Veröffentlichungen

2022 [ nach oben ]

1.
Steinhaeusser, S.C., Oberdörfer, S., von Mammen, S., Latoschik, M.E., Lugrin, B.: Joyful Adventures and Frightening Places - Designing Emotion-Inducing Virtual Environments. Frontiers in Virtual Reality. (2022).
[ BibTeX ] [ URL ] [ DOI ]
 
@article{steinhaeusser2022joyful, author = {Steinhaeusser, Sophia C and Oberdörfer, Sebastian and von Mammen, Sebastian and Latoschik, Marc Erich and Lugrin, Birgit}, journal = {Frontiers in Virtual Reality}, keywords = {birgit endrass lugrin mi myown oberdoerfer}, title = {Joyful Adventures and Frightening Places - Designing Emotion-Inducing Virtual Environments}, year = 2022 }
2.
Riedmann, A., Schaper, P., Lugrin, B.: Integration of a social robot and gamification in adult learning and effects on motivation, engagement and performance. AI & Society. (2022).
[ BibTeX ] [ DOI ]
 
@article{Riedmann_2022, author = {Riedmann, Anna and Schaper, Philipp and Lugrin, Birgit}, journal = {AI & Society}, keywords = {birgit learning mi myown riedmann schaper}, publisher = {Springer}, title = {Integration of a social robot and gamification in adult learning and effects on motivation, engagement and performance}, year = 2022 }
3.
Hoßfeld, T., Raffeck, S., Loh, F., Geißler, S.: Analytical Model for the Energy Efficiency in Low Power IoT Deployments. 1st International Workshop on Network Energy Efficiency in the Softwarization Era (2022).
[ Abstract ] [ BibTeX ]
 
The recent rise of the Internet of Things (IoT) has given way to numerous challenges and research questions. One of the most critical issues in the area of low powered devices is the question of energy efficiency. Here, technologies like LoRa or Zigbee emerged, promising low power consumption while maintaining adequate performance. However, even when using these tailor made technologies, several configuration aspects need to be taken into account to provide high performance, energy efficient operation. To this end, we propose a generic model to compute the energy efficiency of wireless sensors under the assumption of perfect CSMA/CA channel access. We present numerical results for a typical LoRa device and highlight extensions towards other channel access mechanisms. Finally, we apply Kleinrock's power metric to obtain ideal system configurations for varying load parameters.
@inproceedings{info3-inproceedings-2022-6, abstract = {The recent rise of the Internet of Things (IoT) has given way to numerous challenges and research questions. One of the most critical issues in the area of low powered devices is the question of energy efficiency. Here, technologies like LoRa or Zigbee emerged, promising low power consumption while maintaining adequate performance. However, even when using these tailor made technologies, several configuration aspects need to be taken into account to provide high performance, energy efficient operation. To this end, we propose a generic model to compute the energy efficiency of wireless sensors under the assumption of perfect CSMA/CA channel access. We present numerical results for a typical LoRa device and highlight extensions towards other channel access mechanisms. Finally, we apply Kleinrock's power metric to obtain ideal system configurations for varying load parameters.}, author = {Hoßfeld, Tobias and Raffeck, Simon and Loh, Frank and Geißler, Stefan}, booktitle = {1st International Workshop on Network Energy Efficiency in the Softwarization Era}, keywords = {myown can}, month = 6, title = {Analytical Model for the Energy Efficiency in Low Power IoT Deployments}, year = 2022 }
4.
Raffeck, S., Geißler, S., Hoßfeld, T.: DBM: Decentralized Burst Mitigation for Self-Organizing LoRa Deployments. KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2022 (2022).
[ BibTeX ]
 
@inproceedings{info3-inproceedings-2022-7, author = {Raffeck, Simon and Geißler, Stefan and Hoßfeld, Tobias}, booktitle = {KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2022}, keywords = {myown can}, month = 7, title = {DBM: Decentralized Burst Mitigation for Self-Organizing LoRa Deployments}, year = 2022 }
5.
Vomhoff, V., Geißler, S., Hoßfeld, T.: Identification of Signaling Patterns in Mobile IoT Signaling Traffic. WueWoWAS 22 - KuVS Fachgespräch - Würzburg Workshop on Next-Generation Communication Networks (2022).
[ BibTeX ]
 
@inproceedings{info3-inproceedings-2022-8, author = {Vomhoff, Viktoria and Geißler, Stefan and Hoßfeld, Tobias}, booktitle = {WueWoWAS 22 - KuVS Fachgespräch - Würzburg Workshop on Next-Generation Communication Networks}, keywords = {myown 5cale can}, month = 7, title = {Identification of Signaling Patterns in Mobile IoT Signaling Traffic}, year = 2022 }
6.
Henrichs, E., Lesch, V., Straesser, M., Kounev, S., Krupitzer, C.: A literature review on optimization techniques for adaptation planning in adaptive systems: State of the art and research directions. Information and Software Technology. 149, 106940 (2022).
[ Abstract ] [ BibTeX ] [ URL ]
 
Context: Recent developments in modern IT systems including internet of things, edge/fog computing, or cyber–physical systems support intelligent and seamless interaction between users and systems. This requires a reaction to changes in their environment or the system. Adaptive systems provide mechanisms for these reactions. Objective: To implement this functionality, several approaches for the planning of adaptations exist that rely on rules, utility functions, or advanced techniques, such as machine learning. As the adaptation space with possible options is often extensively huge, optimization techniques might support efficient determination of the adaptation space and identify the system’s optimal configuration. With this paper, we provide a systematic review of adaptation planning as the optimization target. Method: In this paper, we review which optimization techniques are applied for adaptation planning in adaptive systems using a systematic literature review approach. Results: We reviewed 115 paper in detail out of an initial search set of 9,588 papers. Our analysis reveals that learning techniques and genetic algorithms are by far dominant; in total, heuristics (anytime learning) are more frequently applied as exact algorithms. We observed that around 57% of the approaches target multi-objectiveness and around 30% integrate distributed optimization. As last dimension, we focused on situation-awareness, which is only supported by two approaches. Conclusion: In this paper, we provide an overview of the current state of the art of approaches that rely on optimization techniques for planning adaptations in adaptive systems and further derive open research challenges, in particular regarding the integration of distributed optimization and situation-awareness.
@article{HENRICHS2022106940, abstract = {Context: Recent developments in modern IT systems including internet of things, edge/fog computing, or cyber–physical systems support intelligent and seamless interaction between users and systems. This requires a reaction to changes in their environment or the system. Adaptive systems provide mechanisms for these reactions. Objective: To implement this functionality, several approaches for the planning of adaptations exist that rely on rules, utility functions, or advanced techniques, such as machine learning. As the adaptation space with possible options is often extensively huge, optimization techniques might support efficient determination of the adaptation space and identify the system’s optimal configuration. With this paper, we provide a systematic review of adaptation planning as the optimization target. Method: In this paper, we review which optimization techniques are applied for adaptation planning in adaptive systems using a systematic literature review approach. Results: We reviewed 115 paper in detail out of an initial search set of 9,588 papers. Our analysis reveals that learning techniques and genetic algorithms are by far dominant; in total, heuristics (anytime learning) are more frequently applied as exact algorithms. We observed that around 57% of the approaches target multi-objectiveness and around 30% integrate distributed optimization. As last dimension, we focused on situation-awareness, which is only supported by two approaches. Conclusion: In this paper, we provide an overview of the current state of the art of approaches that rely on optimization techniques for planning adaptations in adaptive systems and further derive open research challenges, in particular regarding the integration of distributed optimization and situation-awareness.}, author = {Henrichs, Elia and Lesch, Veronika and Straesser, Martin and Kounev, Samuel and Krupitzer, Christian}, journal = {Information and Software Technology}, keywords = {adaptation_optimization descartes planning self_adaptive_systems survey t_journalmagazine myown}, pages = 106940, title = {A literature review on optimization techniques for adaptation planning in adaptive systems: State of the art and research directions}, volume = 149, year = 2022 }
7.
Casas, P., Wassermann, S., Wehner, N., Seufert, M., Hoßfeld, T.: Not all Web Pages are Born the Same. Content Tailored Learning for Web QoE Inference. IEEE International Symposium on Measurements & Networking (M&N 2022) (2022).
[ Abstract ] [ BibTeX ]
 
Web Quality of Experience (QoE) monitoring is a critical task for Internet Service Providers (ISPs), especially due to the key role played by customer experience in churn management. Previously, we have tackled the problem of Web QoE inference from the ISP perspective, relying on passive measurement of encrypted network traffic and machine learning models. In this paper, we exploit the broad heterogeneity of contents embedded in web pages to improve the state of the art performance in Web QoE inference, relying on web-content learning model tailoring. By analyzing the top-500 most popular web pages of the Internet through unsupervised learning, we discover different web page content classes which realize significantly different Web QoE inference performance. We train supervised learning inference models separately for each of these classes, using the well-known Speed Index (SI) metric as proxy to Web QoE. Empirical evaluations on a large corpus of Web QoE measurements for top popular websites demonstrate that our combined content-tailored approach improves the inference performance of the SI by almost 30% with respect to previous single-model approaches, reducing the QoE inference error in terms of mean opinion scores by more than 40%.
@inproceedings{info3-inproceedings-2022-10, abstract = {Web Quality of Experience (QoE) monitoring is a critical task for Internet Service Providers (ISPs), especially due to the key role played by customer experience in churn management. Previously, we have tackled the problem of Web QoE inference from the ISP perspective, relying on passive measurement of encrypted network traffic and machine learning models. In this paper, we exploit the broad heterogeneity of contents embedded in web pages to improve the state of the art performance in Web QoE inference, relying on web-content learning model tailoring. By analyzing the top-500 most popular web pages of the Internet through unsupervised learning, we discover different web page content classes which realize significantly different Web QoE inference performance. We train supervised learning inference models separately for each of these classes, using the well-known Speed Index (SI) metric as proxy to Web QoE. Empirical evaluations on a large corpus of Web QoE measurements for top popular websites demonstrate that our combined content-tailored approach improves the inference performance of the SI by almost 30% with respect to previous single-model approaches, reducing the QoE inference error in terms of mean opinion scores by more than 40%.}, author = {Casas, Pedro and Wassermann, Sarah and Wehner, Nikolas and Seufert, Michael and Hoßfeld, Tobias}, booktitle = {IEEE International Symposium on Measurements & Networking (M&N 2022)}, keywords = {myown}, month = 7, title = {Not all Web Pages are Born the Same. Content Tailored Learning for Web QoE Inference}, year = 2022 }
8.
Riedmann, A., Schaper, P., Donnermann, M., Lein, M., Steinhaeusser, S.C., Karageorgos, P., Müller, B., Richter, T., Lugrin, B.: Iteratively Digitizing an Analogue Syllable-Based Reading Intervention. Interacting with Computers. (2022).
[ BibTeX ] [ DOI ]
 
@article{2022, author = {Riedmann, Anna and Schaper, Philipp and Donnermann, Melissa and Lein, Martina and Steinhaeusser, Sophia C. and Karageorgos, Panagiotis and Müller, Bettina and Richter, Tobias and Lugrin, Birgit}, journal = {Interacting with Computers}, keywords = {MI birgit donnermann learning lein myown riedmann schaper steinhaeusser}, publisher = {Oxford University Press}, title = {Iteratively Digitizing an Analogue Syllable-Based Reading Intervention}, year = 2022 }
9.
Casas, P., Wassermann, S., Seufert, M., Wehner, N., Dinica, O., Hoßfeld, T.: X-Ray Goggles for the ISP: Improving in-Network Web and App QoE Monitoring with Deep Learning. Network Traffic Measurement and Analysis Conference (TMA) (2022).
[ Abstract ] [ BibTeX ]
 
The wide adoption of end-to-end encryption is drastically limiting the visibility Internet Service Providers (ISPs) have on the performance of the services consumed by their customers. In times of strong competition, where customer experience plays a key role in churn management, ISPs require novel solutions enabling network-wide Quality of Experience (QoE) monitoring. To this end, we present DeepQoE, a deep-learning based approach to infer the QoE of web services and mobile applications from the ISP perspective, relying exclusively on the analysis of encrypted network traffic. Using raw features derived from the encrypted stream of bytes as input to deep Convolutional Neural Networks (CNNs), DeepQoE infers the Speed Index of web browsing sessions and general mobile apps with unprecedented accuracy, improving the state of the art by more than 25%, and reducing the QoE inference error in terms of mean opinion scores by nearly 40%. DeepQoE implements a web fingerprinting solution to identify individual web browsing sessions within concurrent web pages traffic, enabling highly detailed, per web page QoE inference in practical deployments. Extensive evaluations over a large and heterogeneous dataset composed of web and app measurements, using different device types and for top-popular websites and apps, confirm the out-performance of DeepQoE over previously used shallow-learning models, as well as the deep-model generalization to different devices, web pages, apps, and network setups. DeepQoE is the first deployable system providing such a deep, highly-detailed QoE for individual web browsing and mobile apps over encrypted traffic, using deep learning models on heterogeneous measurements.
@inproceedings{info3-inproceedings-2022-11, abstract = {The wide adoption of end-to-end encryption is drastically limiting the visibility Internet Service Providers (ISPs) have on the performance of the services consumed by their customers. In times of strong competition, where customer experience plays a key role in churn management, ISPs require novel solutions enabling network-wide Quality of Experience (QoE) monitoring. To this end, we present DeepQoE, a deep-learning based approach to infer the QoE of web services and mobile applications from the ISP perspective, relying exclusively on the analysis of encrypted network traffic. Using raw features derived from the encrypted stream of bytes as input to deep Convolutional Neural Networks (CNNs), DeepQoE infers the Speed Index of web browsing sessions and general mobile apps with unprecedented accuracy, improving the state of the art by more than 25%, and reducing the QoE inference error in terms of mean opinion scores by nearly 40%. DeepQoE implements a web fingerprinting solution to identify individual web browsing sessions within concurrent web pages traffic, enabling highly detailed, per web page QoE inference in practical deployments. Extensive evaluations over a large and heterogeneous dataset composed of web and app measurements, using different device types and for top-popular websites and apps, confirm the out-performance of DeepQoE over previously used shallow-learning models, as well as the deep-model generalization to different devices, web pages, apps, and network setups. DeepQoE is the first deployable system providing such a deep, highly-detailed QoE for individual web browsing and mobile apps over encrypted traffic, using deep learning models on heterogeneous measurements.}, author = {Casas, Pedro and Wassermann, Sarah and Seufert, Michael and Wehner, Nikolas and Dinica, Olivia and Hoßfeld, Tobias}, booktitle = {Network Traffic Measurement and Analysis Conference (TMA)}, keywords = {myown}, month = 6, title = {X-Ray Goggles for the ISP: Improving in-Network Web and App QoE Monitoring with Deep Learning}, year = 2022 }
10.
Geißler, S.: Performance Evaluation of Next-Generation Data Plane Architectures and their Components, (2022).
[ Abstract ] [ BibTeX ]
 
In this doctoral thesis we cover the performance evaluation of next generation data plane architectures, comprised of complex software as well as programmable hardware components that allow fine granular configuration. In the scope of the thesis we propose mechanisms to monitor the performance of singular components and model key performance indicators of software based packet processing solutions. We present novel approaches towards network abstraction that allow the integration of heterogeneous data plane technologies into a singular network while maintaining total transparency between control and data plane. Finally, we investigate a full, complex system consisting of multiple software-based solutions and perform a detailed performance analysis. We employ simulative approaches to investigate overload control mechanisms that allow efficient operation under adversary conditions. The contributions of this work build the foundation for future research in the areas of network softwarization and network function virtualization.
@phdthesis{info3-dissertation-2022-1, abstract = {In this doctoral thesis we cover the performance evaluation of next generation data plane architectures, comprised of complex software as well as programmable hardware components that allow fine granular configuration. In the scope of the thesis we propose mechanisms to monitor the performance of singular components and model key performance indicators of software based packet processing solutions. We present novel approaches towards network abstraction that allow the integration of heterogeneous data plane technologies into a singular network while maintaining total transparency between control and data plane. Finally, we investigate a full, complex system consisting of multiple software-based solutions and perform a detailed performance analysis. We employ simulative approaches to investigate overload control mechanisms that allow efficient operation under adversary conditions. The contributions of this work build the foundation for future research in the areas of network softwarization and network function virtualization.}, author = {Geißler, Stefan}, keywords = {myown 5cale sendate-planets can ngn}, month = 4, school = {University of Würzburg}, title = {Performance Evaluation of Next-Generation Data Plane Architectures and their Components}, year = 2022 }
11.
Wehner, N., Amir, M., Seufert, M., Schatz, R., Hoßfeld, T.: A Vital Improvement? Relating Google’s Core Web Vitals to Actual Web QoE. 14th International Conference on Quality of Multimedia Experience (QoMEX) (2022).
[ Abstract ] [ BibTeX ]
 
Providing sophisticated Web Quality of Experience (QoE) has become paramount for web service providers and network operators alike. Due to advances in Web technologies (HTML5, responsive design, etc.), traditional Web QoE models focusing mainly on loading times have to be refined and improved. In this work, we relate Google's Core Web Vitals, a set of metrics for improving user experience, to the loading time aspects of Web QoE. To this end, we first perform objective measurements in the Web using Google's Lighthouse. To close the gap between metrics and experience, we complement these objective measurements with subjective assessment by performing multiple crowdsourcing QoE studies. In these studies, we use CWeQS, a customized framework to emulate the entire web page loading process, and ask users for their experience while controlling the Core Web Vitals. Our results suggest that the Core Web Vitals have less predictive value for Web QoE than expected and that page loading times remain the main influence factor in this context.
@inproceedings{info3-inproceedings-2022-12, abstract = {Providing sophisticated Web Quality of Experience (QoE) has become paramount for web service providers and network operators alike. Due to advances in Web technologies (HTML5, responsive design, etc.), traditional Web QoE models focusing mainly on loading times have to be refined and improved. In this work, we relate Google's Core Web Vitals, a set of metrics for improving user experience, to the loading time aspects of Web QoE. To this end, we first perform objective measurements in the Web using Google's Lighthouse. To close the gap between metrics and experience, we complement these objective measurements with subjective assessment by performing multiple crowdsourcing QoE studies. In these studies, we use CWeQS, a customized framework to emulate the entire web page loading process, and ask users for their experience while controlling the Core Web Vitals. Our results suggest that the Core Web Vitals have less predictive value for Web QoE than expected and that page loading times remain the main influence factor in this context.}, author = {Wehner, Nikolas and Amir, Monisha and Seufert, Michael and Schatz, Raimund and Hoßfeld, Tobias}, booktitle = {14th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {myown ucn}, month = 9, title = {A Vital Improvement? Relating Google's Core Web Vitals to Actual Web QoE}, year = 2022 }
12.
Schell, C., Sieper, F., Latoschik, M.E.: Who is Alyx?, https://github.com/cschell/who-is-alyx, (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
This dataset contains over 57 hours of motion and eye-tracking data from 37 players of the virtual reality game "Half-Life: Alyx". Each player played the game on two separate days for about 45 minutes using a HTC Vive Pro.
@dataset{who_is_alyx_2022, abstract = {This dataset contains over 57 hours of motion and eye-tracking data from 37 players of the virtual reality game "Half-Life: Alyx". Each player played the game on two separate days for about 45 minutes using a HTC Vive Pro.}, author = {Schell, Christian and Sieper, Fabian and Latoschik, Marc E.}, keywords = {BiometricData Dataset VirtualReality myown}, month = {April}, title = {Who is Alyx?}, year = 2022 }
13.
Metzger, F., Geißler, S., Grigorjew, A., Loh, F., Moldovan, C., Seufert, M., Hoßfeld, T.: An Introduction to Online Video Game QoS and QoE Influencing Factors. IEEE Communications Surveys & Tutorials. (2022).
[ Abstract ] [ BibTeX ]
 
Online video games and cloud gaming are rapidly growing in pervasiveness. Their resource demands can put significant stress on the global communication infrastructure. And network conditions are amongst the chief factors that influence one's enjoyment while playing games. This makes it imperative for video games to be considered for network dimensioning, server placement or protocol development. For that reason, in this work we provide an introduction to the technical aspects of video games in general and of their network aspects in particular. This understanding forms the basis for a rich taxonomy of factors that influence and provide context to a video game's Quality of Service (QoS) and Quality of Experience (QoE). The taxonomy covers influence factors from all aspects involved in a video game, from the subjective player and game influence factors to the system and networking influence factors. Finally, this work gives an overview of conducted and ongoing research as well as future research opportunities while taking into account lessons learned from past approaches.
@article{info3-article-2022-16, abstract = {Online video games and cloud gaming are rapidly growing in pervasiveness. Their resource demands can put significant stress on the global communication infrastructure. And network conditions are amongst the chief factors that influence one's enjoyment while playing games. This makes it imperative for video games to be considered for network dimensioning, server placement or protocol development. For that reason, in this work we provide an introduction to the technical aspects of video games in general and of their network aspects in particular. This understanding forms the basis for a rich taxonomy of factors that influence and provide context to a video game's Quality of Service (QoS) and Quality of Experience (QoE). The taxonomy covers influence factors from all aspects involved in a video game, from the subjective player and game influence factors to the system and networking influence factors. Finally, this work gives an overview of conducted and ongoing research as well as future research opportunities while taking into account lessons learned from past approaches.}, author = {Metzger, Florian and Geißler, Stefan and Grigorjew, Alexej and Loh, Frank and Moldovan, Christian and Seufert, Michael and Hoßfeld, Tobias}, journal = {IEEE Communications Surveys & Tutorials}, keywords = {myown 10.1109/COMST.2022.3177251}, month = 5, title = {An Introduction to Online Video Game QoS and QoE Influencing Factors}, year = 2022 }
14.
Oberdörfer, S., Krop, P., Straka, S., Grafe, S., Latoschik, M.E.: Fly My Little Dragon: Using AR to Learn Geometry. Proceedings of the IEEE Conference on Games (CoG ’22) (2022).
[ BibTeX ]
 
@inproceedings{oberdorfer2022little, author = {Oberdörfer, Sebastian and Krop, Philipp and Straka, Samantha and Grafe, Silke and Latoschik, Marc Erich}, booktitle = {Proceedings of the IEEE Conference on Games (CoG '22)}, keywords = {myown oberdoerfer}, note = {in publication}, title = {Fly My Little Dragon: Using AR to Learn Geometry}, year = 2022 }
15.
Seufert, A., Schweifler, R., Poignée, F., Seufert, M., Hoßfeld, T.: Waiting along the Path: How Browsing Delays Impact the QoE of Music Streaming Applications. 14th International Conference on Quality of Multimedia Experience (QoMEX) (2022).
[ Abstract ] [ BibTeX ]
 
Streaming has become the dominant source of media consumption, which not only applies to the widely researched field of video streaming, but also to music streaming. Here, previous studies so far have only researched the impact of streaming aspects, such as stalling events or initial loading times, on the QoE of music streaming. However, when using a music streaming application, users are already facing waiting times along the click path before they can start the actual streaming. These waiting times are caused by browsing delays, e.g., during searching for songs or scrolling through playlists, and can potentially deteriorate the QoE of the music streaming application. In this work, we conduct an online QoE study to quantify the impact of these browsing delays with the support of an emulated mobile music streaming web app. We found that browsing delays have no impact on the music streaming QoE, which shows that users are able to clearly distinguish between the two main functionalities of such apps, namely, browsing and streaming. However, browsing delays significantly reduce the QoE of the entire music streaming application, to a similar extent as if QoE degradations happen during the actual streaming. This shows that both browsing and streaming are equally important and have to be considered when designing music streaming applications.
@inproceedings{info3-inproceedings-2022-13, abstract = {Streaming has become the dominant source of media consumption, which not only applies to the widely researched field of video streaming, but also to music streaming. Here, previous studies so far have only researched the impact of streaming aspects, such as stalling events or initial loading times, on the QoE of music streaming. However, when using a music streaming application, users are already facing waiting times along the click path before they can start the actual streaming. These waiting times are caused by browsing delays, e.g., during searching for songs or scrolling through playlists, and can potentially deteriorate the QoE of the music streaming application. In this work, we conduct an online QoE study to quantify the impact of these browsing delays with the support of an emulated mobile music streaming web app. We found that browsing delays have no impact on the music streaming QoE, which shows that users are able to clearly distinguish between the two main functionalities of such apps, namely, browsing and streaming. However, browsing delays significantly reduce the QoE of the entire music streaming application, to a similar extent as if QoE degradations happen during the actual streaming. This shows that both browsing and streaming are equally important and have to be considered when designing music streaming applications.}, author = {Seufert, Anika and Schweifler, Ralf and Poignée, Fabian and Seufert, Michael and Hoßfeld, Tobias}, booktitle = {14th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {myown}, month = 9, title = {Waiting along the Path: How Browsing Delays Impact the QoE of Music Streaming Applications}, year = 2022 }
16.
Zink, J., Walter, J., Baumeister, J., Wolff, A.: Layered drawing of undirected graphs with generalized port constraints. Computational Geometry: Theory and Applications. 105-106, 101886 (2022).
[ Abstract ] [ BibTeX ]
 
The aim of this research is a practical method to draw cable plans of complex machines. Such plans consist of electronic components and cables connecting specific ports of the components. Since the machines are configured for each client individually, cable plans need to be drawn automatically. The drawings must be well readable so that technicians can use them to debug the machines. In order to model plug sockets, we introduce port groups; within a group, ports can change their position (which we use to improve the aesthetics of the layout), but together the ports of a group must form a contiguous block. We approach the problem of drawing such cable plans by extending the well-known Sugiyama framework such that it incorporates ports and port groups. Since the framework assumes directed graphs, we propose several ways to orient the edges of the given undirected graph. We compare these methods experimentally, both on real-world data and synthetic data that carefully simulates real-world data. We measure the aesthetics of the resulting drawings by counting bends and crossings. Using these metrics, we experimentally compare our approach to Kieler JVLC 2014, a library for drawing graphs in the presence of port constraints. Our method produced 10--30 % fewer crossings, while it performed equally well or slightly worse than Kieler with respect to the number of bends and the time used to compute a drawing.
@article{ZINK2022101886, abstract = {The aim of this research is a practical method to draw cable plans of complex machines. Such plans consist of electronic components and cables connecting specific ports of the components. Since the machines are configured for each client individually, cable plans need to be drawn automatically. The drawings must be well readable so that technicians can use them to debug the machines. In order to model plug sockets, we introduce port groups; within a group, ports can change their position (which we use to improve the aesthetics of the layout), but together the ports of a group must form a contiguous block. We approach the problem of drawing such cable plans by extending the well-known Sugiyama framework such that it incorporates ports and port groups. Since the framework assumes directed graphs, we propose several ways to orient the edges of the given undirected graph. We compare these methods experimentally, both on real-world data and synthetic data that carefully simulates real-world data. We measure the aesthetics of the resulting drawings by counting bends and crossings. Using these metrics, we experimentally compare our approach to Kieler JVLC 2014, a library for drawing graphs in the presence of port constraints. Our method produced 10–30 \% fewer crossings, while it performed equally well or slightly worse than Kieler with respect to the number of bends and the time used to compute a drawing.}, author = {Zink, Johannes and Walter, Julian and Baumeister, Joachim and Wolff, Alexander}, journal = {Computational Geometry: Theory and Applications}, keywords = {myown rokt}, pages = 101886, title = {Layered drawing of undirected graphs with generalized port constraints}, volume = {105-106}, year = 2022 }
17.
Straesser, M., Grohmann, J., von Kistowski, J., Eismann, S., Bauer, A., Kounev, S.: Why Is It Not Solved Yet? Challenges for Production-Ready Autoscaling. Proceedings of the 2022 ACM/SPEC on International Conference on Performance Engineering. S. 105–115. Association for Computing Machinery, New York, NY, USA (2022).
[ Abstract ] [ BibTeX ] [ URL ]
 
Autoscaling is a task of major importance in the cloud computing domain as it directly affects both operating costs and customer experience. Although there has been active research in this area for over ten years now, there is still a significant gap between the proposed methods in the literature and the deployed autoscalers in practice. Hence, many research autoscalers do not find their way into production deployments. This paper describes six core challenges that arise in production systems that are still not solved by most research autoscalers. We illustrate these problems through experiments in a realistic cloud environment with a real-world multi-service business application and show that commonly used autoscalers have various shortcomings. In addition, we analyze the behavior of overloaded services and show that these can be problematic for existing autoscalers. Generally, we analyze that these challenges are only insufficiently addressed in the literature and conclude that future scaling approaches should focus on the needs of production systems.
@inproceedings{10.1145/3489525.3511680, abstract = {Autoscaling is a task of major importance in the cloud computing domain as it directly affects both operating costs and customer experience. Although there has been active research in this area for over ten years now, there is still a significant gap between the proposed methods in the literature and the deployed autoscalers in practice. Hence, many research autoscalers do not find their way into production deployments. This paper describes six core challenges that arise in production systems that are still not solved by most research autoscalers. We illustrate these problems through experiments in a realistic cloud environment with a real-world multi-service business application and show that commonly used autoscalers have various shortcomings. In addition, we analyze the behavior of overloaded services and show that these can be problematic for existing autoscalers. Generally, we analyze that these challenges are only insufficiently addressed in the literature and conclude that future scaling approaches should focus on the needs of production systems.}, address = {New York, NY, USA}, author = {Straesser, Martin and Grohmann, Johannes and von Kistowski, J{ó}akim and Eismann, Simon and Bauer, Andr{é} and Kounev, Samuel}, booktitle = {Proceedings of the 2022 ACM/SPEC on International Conference on Performance Engineering}, keywords = {autoscaling cloud_computing descartes microservices t_full myown}, pages = {105–115}, publisher = {Association for Computing Machinery}, series = {ICPE '22}, title = {Why Is It Not Solved Yet? Challenges for Production-Ready Autoscaling}, year = 2022 }
18.
Casas, P., Seufert, M., Wassermann, S., Gardlo, B., Wehner, N., Schatz, R.: DeepCrypt - Deep Learning for QoE Monitoring and Fingerprinting of User Actions in Adaptive Video Streaming. IEEE Conference on Network Softwarization (IEEE NetSoft 2022) (2022).
[ Abstract ] [ BibTeX ]
 
We introduce DeepCrypt, a deep-learning based approach to analyze YouTube video streaming Quality of Experience (QoE) from the Internet Service Provider (ISP) perspective, relying exclusively on the analysis of encrypted network traffic. Using raw features derived on-line from the encrypted stream of bytes, DeepCrypt can infer six different video QoE indicators capturing the user-perceived performance of the service, including the initial playback delay, the number and frequency of rebuffering events, the video playback quality, the video encoding bitrate, and the number of quality changes. DeepCrypt offers deep visibility into the behavior of the end-user, enabling the fingerprinting and detection of different user actions on the video player, such as video pauses and playback scrubbing (forward, backward, out-of-buffer), offering a complete visibility on the video streaming process from in-network traffic measurements. Extensive evaluations over a large and heterogeneous dataset composed of mobile and fixed-line measurements, using the YouTube HTML5 player, the native YouTube mobile app, as well as a generic HTML5 video player built on top of open source libraries, and considering measurements collected at different ISPs, confirm the out-performance of DeepCrypt over previously used shallow-learning models, as well as the deep-model generalization to different video players and network setups. To the best of our knowledge, this is the first paper tackling such a combined QoE and user-actions approach for video streaming applications, using deep learning models over heterogeneous measurements.
@inproceedings{info3-inproceedings-2022-9, abstract = {We introduce DeepCrypt, a deep-learning based approach to analyze YouTube video streaming Quality of Experience (QoE) from the Internet Service Provider (ISP) perspective, relying exclusively on the analysis of encrypted network traffic. Using raw features derived on-line from the encrypted stream of bytes, DeepCrypt can infer six different video QoE indicators capturing the user-perceived performance of the service, including the initial playback delay, the number and frequency of rebuffering events, the video playback quality, the video encoding bitrate, and the number of quality changes. DeepCrypt offers deep visibility into the behavior of the end-user, enabling the fingerprinting and detection of different user actions on the video player, such as video pauses and playback scrubbing (forward, backward, out-of-buffer), offering a complete visibility on the video streaming process from in-network traffic measurements. Extensive evaluations over a large and heterogeneous dataset composed of mobile and fixed-line measurements, using the YouTube HTML5 player, the native YouTube mobile app, as well as a generic HTML5 video player built on top of open source libraries, and considering measurements collected at different ISPs, confirm the out-performance of DeepCrypt over previously used shallow-learning models, as well as the deep-model generalization to different video players and network setups. To the best of our knowledge, this is the first paper tackling such a combined QoE and user-actions approach for video streaming applications, using deep learning models over heterogeneous measurements.}, author = {Casas, Pedro and Seufert, Michael and Wassermann, Sarah and Gardlo, Bruno and Wehner, Nikolas and Schatz, Raimund}, booktitle = {IEEE Conference on Network Softwarization (IEEE NetSoft 2022)}, keywords = {myown}, month = 6, title = {DeepCrypt - Deep Learning for QoE Monitoring and Fingerprinting of User Actions in Adaptive Video Streaming}, year = 2022 }
19.
Raffeck, S., Geißler, S., Krolikowski, M., Gebert, S., Hoßfeld, T.: Anonymized GTP Tunnel Trace in Mobile IoT, (2022).
[ Abstract ] [ BibTeX ]
 
Extensive dataset containing one whole month of create and delete events as well as the total, received, and transmitted volume of devices. We obtained data tunnel related events and volume values over 30 days in October 2021. In total the dataset contains a sample of 500000 unique devices that generate 155 million individual data tunnels.
@misc{info3-misc-2022-1, abstract = {Extensive dataset containing one whole month of create and delete events as well as the total, received, and transmitted volume of devices. We obtained data tunnel related events and volume values over 30 days in October 2021. In total the dataset contains a sample of 500000 unique devices that generate 155 million individual data tunnels.}, author = {Raffeck, Simon and Geißler, Stefan and Krolikowski, Michael and Gebert, Steffen and Hoßfeld, Tobias}, howpublished = {https://zenodo.org/record/6045708}, keywords = {myown 5cale can}, month = 2, title = {Anonymized GTP Tunnel Trace in Mobile IoT}, year = 2022 }
20.
Zimmerer, C., Krop, P., Fischbach, M., Latoschik, M.E.: Reducing the Cognitive Load of Playing a Digital Tabletop Game with a Multimodal Interface. CHI Conference on Human Factors in Computing Systems. Association for Computing Machinery, New Orleans, LA, USA (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Multimodal Interfaces (MMIs) combining speech and spatial input have the potential to elicit minimal cognitive load. Low cognitive load increases effectiveness as well as user satisfaction and is regarded as an important aspect of intuitive use. While this potential has been extensively theorized in the research community, experiments that provide supporting observations based on functional interfaces are still scarce. In particular, there is a lack of studies comparing the commonly used Unimodal Interfaces (UMIs) with theoretically superior synergistic MMI alternatives. Yet, these studies are an essential prerequisite for generalizing results, developing practice-oriented guidelines, and ultimately exploiting the potential of MMIs in a broader range of applications. This work contributes a novel observation towards the resolution of this shortcoming in the context of the following combination of applied interaction techniques, tasks, application domain, and technology: We present a comprehensive evaluation of a synergistic speech & touch MMI and a touch-only menu-based UMI (interaction techniques) for selection and system control tasks in a digital tabletop game (application domain) on an interactive surface (technology). Cognitive load, user experience, and intuitive use are evaluated, with the former being assessed by means of the dual-task paradigm. Our experiment shows that the implemented MMI causes significantly less cognitive load and is perceived significantly more usable and intuitive than the UMI. Based on our results, we derive recommendations for the interface design of digital tabletop games on interactive surfaces. Further, we argue that our results and design recommendations are suitable to be generalized to other application domains on interactive surfaces for selection and system control tasks.
@inproceedings{10.1145/3491102.3502062, abstract = {Multimodal Interfaces (MMIs) combining speech and spatial input have the potential to elicit minimal cognitive load. Low cognitive load increases effectiveness as well as user satisfaction and is regarded as an important aspect of intuitive use. While this potential has been extensively theorized in the research community, experiments that provide supporting observations based on functional interfaces are still scarce. In particular, there is a lack of studies comparing the commonly used Unimodal Interfaces (UMIs) with theoretically superior synergistic MMI alternatives. Yet, these studies are an essential prerequisite for generalizing results, developing practice-oriented guidelines, and ultimately exploiting the potential of MMIs in a broader range of applications. This work contributes a novel observation towards the resolution of this shortcoming in the context of the following combination of applied interaction techniques, tasks, application domain, and technology: We present a comprehensive evaluation of a synergistic speech & touch MMI and a touch-only menu-based UMI (interaction techniques) for selection and system control tasks in a digital tabletop game (application domain) on an interactive surface (technology). Cognitive load, user experience, and intuitive use are evaluated, with the former being assessed by means of the dual-task paradigm. Our experiment shows that the implemented MMI causes significantly less cognitive load and is perceived significantly more usable and intuitive than the UMI. Based on our results, we derive recommendations for the interface design of digital tabletop games on interactive surfaces. Further, we argue that our results and design recommendations are suitable to be generalized to other application domains on interactive surfaces for selection and system control tasks.}, address = {New York, NY, USA}, author = {Zimmerer, Chris and Krop, Philipp and Fischbach, Martin and Latoschik, Marc Erich}, booktitle = {CHI Conference on Human Factors in Computing Systems}, keywords = {mmi myown}, publisher = {Association for Computing Machinery}, series = {CHI '22}, title = {Reducing the Cognitive Load of Playing a Digital Tabletop Game with a Multimodal Interface}, year = 2022 }
21.
Bauer, A., Straesser, M., Beierlieb, L., Meissner, M., Kounev, S.: Automated Triage of Performance Change Points Using Time Series Analysis and Machine Learning. Proceedings of the 2022 ACM/SPEC on International Conference on Performance Engineering. ACM (2022).
[ BibTeX ]
 
@conference{bauer2022automated, author = {Bauer, André and Straesser, Martin and Beierlieb, Lukas and Meissner, Maximilian and Kounev, Samuel}, booktitle = {Proceedings of the 2022 ACM/SPEC on International Conference on Performance Engineering}, keywords = {descartes machine_learning myown t_short timeseries}, month = 4, publisher = {ACM}, title = {Automated Triage of Performance Change Points Using Time Series Analysis and Machine Learning}, year = 2022 }
22.
Evans, W.S., Fleszar, K., Kindermann, P., Saeedi, N., Shin, C.-S., Wolff, A.: Minimum Rectilinear Polygons for Given Angle Sequences. Computational Geometry: Theory and Applications. 100, 1–39 (2022).
[ Abstract ] [ BibTeX ] [ DOI ]
 
A rectilinear polygon is a simple polygon whose edges are axis-aligned. Walking counterclockwise on the boundary of such a polygon yields a sequence of left turns and right turns. The number of left turns always equals the number of right turns plus four. It is known that any such sequence can be realized by a rectilinear polygon. par In this paper, we consider the problem of finding realizations that minimize the perimeter or the area of the polygon or the area of the bounding box of the polygon. We show that all three problems are NP-hard in general. This answers an open question of Patrignani [CGTA 2001], who showed that it is NP-hard to minimize the area of the bounding box of an orthogonal drawing of a given planar graph. We also show that realizing a polyline within a bounding box of minimum area (or within a fixed given rectangle) is NP-hard. Then we consider the special cases of x-monotone and xy-monotone rectilinear polygons. For these, we can optimize the three objectives efficiently.
@article{efkssw-mrpga-CGTA22, abstract = {A rectilinear polygon is a simple polygon whose edges are axis-aligned. Walking counterclockwise on the boundary of such a polygon yields a sequence of left turns and right turns. The number of left turns always equals the number of right turns plus four. It is known that any such sequence can be realized by a rectilinear polygon. \par In this paper, we consider the problem of finding realizations that minimize the perimeter or the area of the polygon or the area of the bounding box of the polygon. We show that all three problems are NP-hard in general. This answers an open question of Patrignani [CGTA 2001], who showed that it is NP-hard to minimize the area of the bounding box of an orthogonal drawing of a given planar graph. We also show that realizing a polyline within a bounding box of minimum area (or within a fixed given rectangle) is NP-hard. Then we consider the special cases of x-monotone and xy-monotone rectilinear polygons. For these, we can optimize the three objectives efficiently.}, author = {Evans, William S. and Fleszar, Krzysztof and Kindermann, Philipp and Saeedi, Noushin and Shin, Chan-Su and Wolff, Alexander}, journal = {Computational Geometry: Theory and Applications}, keywords = {myown}, number = 101820, pages = {1–39}, title = {Minimum Rectilinear Polygons for Given Angle Sequences}, volume = 100, year = 2022 }
23.
Hadry, M., Lesch, V., Kounev, S.: FADE: Towards Flexible and Adaptive Distance Estimation Considering Obstacles. Companion of the 13th ACM/SPEC International Conference on Performance Engineering (ICPE 2022). ACM (2022).
[ BibTeX ]
 
@inproceedings{hadry2022towards, author = {Hadry, Marius and Lesch, Veronika and Kounev, Samuel}, booktitle = {Companion of the 13th ACM/SPEC International Conference on Performance Engineering (ICPE 2022)}, keywords = {select myown descartes intelligent_transportation_systems t_visionposition cyber-physical_systems}, month = {April}, publisher = {ACM}, title = {FADE: Towards Flexible and Adaptive Distance Estimation Considering Obstacles}, year = 2022 }
24.
Seufert, A., Poignée, F., Hoßfeld, T., Seufert, M.: Pandemic in the Digital Age: Analyzing WhatsApp Communication Behavior before, during, and after the COVID-19 Lockdown. Humanities and Social Sciences Communications. 9, 140 (1–9) (2022).
[ Abstract ] [ BibTeX ]
 
The strict restrictions introduced by the COVID-19 lockdowns, which started from March 2020, changed people’s daily lives and habits on many different levels. In this work, we investigate the impact of the lockdown on the communication behavior in the mobile instant messaging application WhatsApp. Our evaluations are based on a large dataset of 2577 private chat histories with 25,378,093 messages from 51,973 users. The analysis of the one-to-one and group conversations confirms that the lockdown severely altered the communication in WhatsApp chats compared to pre-pandemic time ranges. In particular, we observe short-term effects, which caused an increased message frequency in the first lockdown months and a shifted communication activity during the day in March and April 2020. Moreover, we also see long-term effects of the ongoing pandemic situation until February 2021, which indicate a change of communication behavior towards more regular messaging, as well as a persisting change in activity during the day. The results of our work show that even anonymized chat histories can tell us a lot about people’s behavior and especially behavioral changes during the COVID-19 pandemic and thus are of great relevance for behavioral researchers. Furthermore, looking at the pandemic from an Internet provider perspective, these insights can be used during the next pandemic, or if the current COVID-19 situation worsens, to adapt communication networks to the changed usage behavior early on and thus avoid network congestion.
@article{info3-article-2022-14, abstract = {The strict restrictions introduced by the COVID-19 lockdowns, which started from March 2020, changed people’s daily lives and habits on many different levels. In this work, we investigate the impact of the lockdown on the communication behavior in the mobile instant messaging application WhatsApp. Our evaluations are based on a large dataset of 2577 private chat histories with 25,378,093 messages from 51,973 users. The analysis of the one-to-one and group conversations confirms that the lockdown severely altered the communication in WhatsApp chats compared to pre-pandemic time ranges. In particular, we observe short-term effects, which caused an increased message frequency in the first lockdown months and a shifted communication activity during the day in March and April 2020. Moreover, we also see long-term effects of the ongoing pandemic situation until February 2021, which indicate a change of communication behavior towards more regular messaging, as well as a persisting change in activity during the day. The results of our work show that even anonymized chat histories can tell us a lot about people’s behavior and especially behavioral changes during the COVID-19 pandemic and thus are of great relevance for behavioral researchers. Furthermore, looking at the pandemic from an Internet provider perspective, these insights can be used during the next pandemic, or if the current COVID-19 situation worsens, to adapt communication networks to the changed usage behavior early on and thus avoid network congestion.}, author = {Seufert, Anika and Poignée, Fabian and Hoßfeld, Tobias and Seufert, Michael}, journal = {Humanities and Social Sciences Communications}, keywords = {myown gbc ucn}, month = 4, number = 1, pages = {140 (1-9)}, title = {Pandemic in the Digital Age: Analyzing WhatsApp Communication Behavior before, during, and after the COVID-19 Lockdown}, volume = 9, year = 2022 }
25.
Prantl, T., Engel, S., Bauer, A., Ben Yahya, A.E., Herrnleben, S., Iffländer, L., Dmitrienko, A., Kounev, S.: An Experience Report on the Suitability of a Distributed Group Encryption Scheme for an IoT Use Case. 2022 IEEE 95th Vehicular Technology Conference (VTC2022. IEEE (2022).
[ BibTeX ]
 
@inproceedings{PrEnBaAlHeIfDmKo2022-IoT/CPS-DistributedGroupEncryption, author = {Prantl, Thomas and Engel, Simon and Bauer, Andre and Ben Yahya, Ala Eddine and Herrnleben, Stefan and Iffländer, Lukas and Dmitrienko, Alexandra and Kounev, Samuel}, booktitle = {2022 IEEE 95th Vehicular Technology Conference (VTC2022}, keywords = {descartes t_workshop myown}, organization = {IEEE}, title = {An Experience Report on the Suitability of a Distributed Group Encryption Scheme for an IoT Use Case}, year = 2022 }
26.
Glémarec, Y., Lugrin, J.-L., Bosser, A.-G., Buche, C., Latoschik, M.E.: Controlling the STAGE: A High-Level Control System for Virtual Audiences In Virtual Reality. Frontiers in Virtual Reality – Virtual Reality and Human Behaviour. (2022).
[ Abstract ] [ BibTeX ] [ URL ]
 
This article presents a novel method for controlling a virtual audience system (VAS) in Virtual Reality (VR) application, called STAGE, which has been originally designed for supervised public speaking training in university seminars dedicated to the preparation and delivery of scientific talks. We are interested in creating pedagogical \emphnarratives: narratives encompass affective phenomena and rather than organizing events changing the course of a training scenario, pedagogical plans using our system focus on organizing the affects it arouses for the trainees. Efficiently controlling a virtual audience towards a specific training objective while evaluating the speaker's performance presents a challenge for a seminar instructor: the high level of cognitive and physical demands required to be able to control the virtual audience, whilst evaluating speaker's performance, adjusting and allowing it to quickly react to the user’s behaviors and interactions. It is indeed a critical limitation of a number of existing systems that they rely on a Wizard of Oz approach, where the tutor drives the audience in reaction to the user’s performance. We address this problem by integrating with a VAS a high-level control component for tutors, which allows using predefined audience behavior rules, defining custom ones, as well as intervening during run-time for finer control of the unfolding of the pedagogical plan. At its core, this component offers a tool to program, select, modify and monitor interactive training narratives using a high-level representation. The STAGE offers the following features: i) a high-level API to program pedagogical narratives focusing on a specific public speaking situation and training objectives, ii) an interactive visualization interface iii) computation and visualization of user metrics, iv) a semi-autonomous virtual audience composed of virtual spectators with automatic reactions to the speaker and surrounding spectators while following the pedagogical plan V) and the possibility for the instructor to embody a virtual spectator to ask questions or guide the speaker from within the Virtual Environment. We present here the design, implementation of the tutoring system and its integration in STAGE, and discuss its reception by end-users.
@article{glemarec2022controlling, abstract = {This article presents a novel method for controlling a virtual audience system (VAS) in Virtual Reality (VR) application, called STAGE, which has been originally designed for supervised public speaking training in university seminars dedicated to the preparation and delivery of scientific talks. We are interested in creating pedagogical \emph{narratives}: narratives encompass affective phenomena and rather than organizing events changing the course of a training scenario, pedagogical plans using our system focus on organizing the affects it arouses for the trainees. Efficiently controlling a virtual audience towards a specific training objective while evaluating the speaker's performance presents a challenge for a seminar instructor: the high level of cognitive and physical demands required to be able to control the virtual audience, whilst evaluating speaker's performance, adjusting and allowing it to quickly react to the user’s behaviors and interactions. It is indeed a critical limitation of a number of existing systems that they rely on a Wizard of Oz approach, where the tutor drives the audience in reaction to the user’s performance. We address this problem by integrating with a VAS a high-level control component for tutors, which allows using predefined audience behavior rules, defining custom ones, as well as intervening during run-time for finer control of the unfolding of the pedagogical plan. At its core, this component offers a tool to program, select, modify and monitor interactive training narratives using a high-level representation. The STAGE offers the following features: i) a high-level API to program pedagogical narratives focusing on a specific public speaking situation and training objectives, ii) an interactive visualization interface iii) computation and visualization of user metrics, iv) a semi-autonomous virtual audience composed of virtual spectators with automatic reactions to the speaker and surrounding spectators while following the pedagogical plan V) and the possibility for the instructor to embody a virtual spectator to ask questions or guide the speaker from within the Virtual Environment. We present here the design, implementation of the tutoring system and its integration in STAGE, and discuss its reception by end-users.}, author = {Glémarec, Yann and Lugrin, Jean-Luc and Bosser, Anne-Gwenn and Buche, Cedric and Latoschik, Marc Erich}, journal = {Frontiers in Virtual Reality – Virtual Reality and Human Behaviour}, keywords = {myown}, title = {Controlling the STAGE: A High-Level Control System for Virtual Audiences In Virtual Reality}, year = 2022 }
27.
Riedmann, A., Schaper, P., Jakob, B., Lugrin, B.: A Theory Based Adaptive Pedagogical Agent in a Reading App for Primary Students - A User Study. In: Crossley, S. und Popescu, E. (hrsg.) Intelligent Tutoring Systems. ITS 2022. Lecture Notes in Computer Science. Springer (2022).
[ BibTeX ] [ DOI ]
 
@inproceedings{riedmann2022theory, author = {Riedmann, Anna and Schaper, Philipp and Jakob, Benedikt and Lugrin, Birgit}, booktitle = {Intelligent Tutoring Systems. ITS 2022. Lecture Notes in Computer Science}, editor = {Crossley, S. and Popescu, E.}, keywords = {birgit learning mi myown riedmann schaper}, publisher = {Springer}, title = {A Theory Based Adaptive Pedagogical Agent in a Reading App for Primary Students - A User Study}, volume = 13284, year = 2022 }
28.
Zimmerer, C., Fischbach, M., Latoschik, M.E.: A Case Study on the Rapid Development of Natural and Synergistic Multimodal Interfaces for XR Use-Cases. CHI Conference on Human Factors in Computing Systems Extended Abstracts. Association for Computing Machinery, New Orleans, LA, USA (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Multimodal Interfaces (MMIs) supporting the synergistic use of natural modalities like speech and gesture have been conceived as promising for spatial or 3D interactions, e.g., in Virtual, Augmented, and Mixed Reality (XR for short). Yet, the currently prevailing user interfaces are unimodal. Commercially available software platforms like the Unity or Unreal game engines simplify the complexity of developing XR applications through appropriate tool support. They provide ready-to-use device integration, e.g., for 3D controllers or motion tracking, and according interaction techniques such as menus, (3D) point-and-click, or even simple symbolic gestures to rapidly develop unimodal interfaces. A comparable tool support is yet missing for multimodal solutions in this and similar areas. We believe that this hinders user-centered research based on rapid prototyping of MMIs, the identification and formulation of practical design guidelines, the development of killer applications highlighting the power of MMIs, and ultimately a widespread adoption of MMIs. This article investigates potential reasons for the ongoing uncommonness of MMIs. Our case study illustrates and analyzes lessons learned during the development and application of a toolchain that supports rapid development of natural and synergistic MMIs for XR use-cases. We analyze the toolchain in terms of developer usability, development time, and MMI customization. This analysis is based on the knowledge gained in years of research and academic education. Specifically, it reflects on the development of appropriate MMI tools and their application in various demo use-cases, in user-centered research, and in the lab work of a mandatory MMI course of an HCI master’s program. The derived insights highlight successful choices made as well as potential areas for improvement.
@inproceedings{10.1145/3491101.3503552, abstract = {Multimodal Interfaces (MMIs) supporting the synergistic use of natural modalities like speech and gesture have been conceived as promising for spatial or 3D interactions, e.g., in Virtual, Augmented, and Mixed Reality (XR for short). Yet, the currently prevailing user interfaces are unimodal. Commercially available software platforms like the Unity or Unreal game engines simplify the complexity of developing XR applications through appropriate tool support. They provide ready-to-use device integration, e.g., for 3D controllers or motion tracking, and according interaction techniques such as menus, (3D) point-and-click, or even simple symbolic gestures to rapidly develop unimodal interfaces. A comparable tool support is yet missing for multimodal solutions in this and similar areas. We believe that this hinders user-centered research based on rapid prototyping of MMIs, the identification and formulation of practical design guidelines, the development of killer applications highlighting the power of MMIs, and ultimately a widespread adoption of MMIs. This article investigates potential reasons for the ongoing uncommonness of MMIs. Our case study illustrates and analyzes lessons learned during the development and application of a toolchain that supports rapid development of natural and synergistic MMIs for XR use-cases. We analyze the toolchain in terms of developer usability, development time, and MMI customization. This analysis is based on the knowledge gained in years of research and academic education. Specifically, it reflects on the development of appropriate MMI tools and their application in various demo use-cases, in user-centered research, and in the lab work of a mandatory MMI course of an HCI master’s program. The derived insights highlight successful choices made as well as potential areas for improvement.}, address = {New York, NY, USA}, author = {Zimmerer, Chris and Fischbach, Martin and Latoschik, Marc Erich}, booktitle = {CHI Conference on Human Factors in Computing Systems Extended Abstracts}, keywords = {mmi myown}, publisher = {Association for Computing Machinery}, series = {CHI EA '22}, title = {A Case Study on the Rapid Development of Natural and Synergistic Multimodal Interfaces for XR Use-Cases}, year = 2022 }
29.
Krop, P., Straka, S., Ullrich, M., Ertl, M., Latoschik, M.E.: IT-Supported Request Management for Clinical Radiology: Contextual Design and Remote Prototype Testing. CHI Conference on Human Factors in Computing Systems Extended Abstracts. S. 1–8. Association for Computing Machinery, New York, NY, USA (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Management of radiology requests in larger clinical contexts is characterized by a complex and distributed workflow. In our partner hospital, representing many similar clinics, these processes often still rely on exchanging physical papers and forms, making patient or case data challenging to access. This often leads to phone calls with long waiting queues, which are time-inefficient and result in frequent interrupts. We report on a user-centered design approach based on Rapid Contextual Design with an additional focus group to optimize and iteratively develop a new workflow. Participants found our prototypes fast and intuitive, the design clean and consistent, relevant information easy to access, and the request process fast and easy. Due to the COVID pandemic, we switched to remote prototype testing, which yielded equally good feedback and increased the participation rate. In the end, we propose best practices for remote prototype testing in hospitals with complex and distributed workflows.
@inproceedings{krop2022a, abstract = {Management of radiology requests in larger clinical contexts is characterized by a complex and distributed workflow. In our partner hospital, representing many similar clinics, these processes often still rely on exchanging physical papers and forms, making patient or case data challenging to access. This often leads to phone calls with long waiting queues, which are time-inefficient and result in frequent interrupts. We report on a user-centered design approach based on Rapid Contextual Design with an additional focus group to optimize and iteratively develop a new workflow. Participants found our prototypes fast and intuitive, the design clean and consistent, relevant information easy to access, and the request process fast and easy. Due to the COVID pandemic, we switched to remote prototype testing, which yielded equally good feedback and increased the participation rate. In the end, we propose best practices for remote prototype testing in hospitals with complex and distributed workflows.}, address = {New York, NY, USA}, author = {Krop, Philipp and Straka, Samantha and Ullrich, Melanie and Ertl, Maximilian and Latoschik, Marc Erich}, booktitle = {CHI Conference on Human Factors in Computing Systems Extended Abstracts}, keywords = {dzptm krop latoschik myown straka}, month = {April}, number = 45, pages = {1-8}, publisher = {Association for Computing Machinery}, series = {CHI EA '22}, title = {IT-Supported Request Management for Clinical Radiology: Contextual Design and Remote Prototype Testing}, year = 2022 }
30.
Hein, R., Steinbock, J., Eisenmann, M., Wienrich, C., Latoschik, M.E.: Virtual Reality im modernen Englischunterricht und das Potenzial für Inter- und Transkulturelles Lernen. MedienPädagogik Zeitschrift für Theorie und Praxis der Medienbildung. 47, 246–266 (2022).
[ BibTeX ] [ URL ] [ DOI ]
 
@article{hein2021medienpaed, author = {Hein, Rebecca and Steinbock, Jeanine and Eisenmann, Maria and Wienrich, Carolin and Latoschik, Marc Erich}, journal = {MedienPädagogik Zeitschrift für Theorie und Praxis der Medienbildung}, keywords = {c.wienrich coteach myown rhein}, pages = {246-266}, title = {Virtual Reality im modernen Englischunterricht und das Potenzial für Inter- und Transkulturelles Lernen}, volume = 47, year = 2022 }
31.
Steinhaeusser, S.C., Lugrin, B.: Effects of Colored LEDs in Robotic Storytelling on Storytelling Experience and Robot Perception. Proceedings of the 2022 ACM/IEEE International Conference on Human-Robot Interaction (HRI2022). IEEE Press (2022).
[ BibTeX ]
 
@inproceedings{steinhaeusser2022effects, author = {Steinhaeusser, Sophia C. and Lugrin, Birgit}, booktitle = {Proceedings of the 2022 ACM/IEEE International Conference on Human-Robot Interaction (HRI2022)}, keywords = {birgit mi myown steinhaeusser storyteller}, publisher = {IEEE Press}, title = {Effects of Colored LEDs in Robotic Storytelling on Storytelling Experience and Robot Perception}, year = 2022 }
32.
Leznik, M., Grohmann, J., Kliche, N., Bauer, A., Seybold, D., Eismann, S., Kounev, S., Domaschka, J.: Same, Same, but Dissimilar: Exploring Measurements for Workload Time-Series Similarity. Proceedings of the 2022 ACM/SPEC on International Conference on Performance Engineering. S. 89–96. Association for Computing Machinery, New York, NY, USA (2022).
[ Abstract ] [ BibTeX ] [ URL ]
 
Benchmarking is a core element in the toolbox of most systems researchers and is used for analyzing, comparing, and validating complex systems. In the quest for reliable benchmark results, a consensus has formed that a significant experiment must be based on multiple runs. To interpret these runs, mean and standard deviation are often used. In case of experiments where each run produces a time series, applying and comparing the mean is not easily applicable and not necessarily statistically sound. Such an approach ignores the possibility of significant differences between runs with a similar average. In order to verify this hypothesis, we conducted a survey of 1,112 publications of selected performance engineering and systems conferences canvassing open data sets from performance experiments. The identified 3 data sets purely rely on average and standard deviation. Therefore, we propose a novel analysis approach based on similarity analysis to enhance the reliability of performance evaluations. Our approach evaluates 12 (dis-)similarity measures with respect to their applicability in analysing performance measurements and identifies four suitable similarity measures. We validate our approach by demonstrating the increase in reliability for the data sets found in the survey.
@inproceedings{leznik2022dissimilar, abstract = {Benchmarking is a core element in the toolbox of most systems researchers and is used for analyzing, comparing, and validating complex systems. In the quest for reliable benchmark results, a consensus has formed that a significant experiment must be based on multiple runs. To interpret these runs, mean and standard deviation are often used. In case of experiments where each run produces a time series, applying and comparing the mean is not easily applicable and not necessarily statistically sound. Such an approach ignores the possibility of significant differences between runs with a similar average. In order to verify this hypothesis, we conducted a survey of 1,112 publications of selected performance engineering and systems conferences canvassing open data sets from performance experiments. The identified 3 data sets purely rely on average and standard deviation. Therefore, we propose a novel analysis approach based on similarity analysis to enhance the reliability of performance evaluations. Our approach evaluates 12 (dis-)similarity measures with respect to their applicability in analysing performance measurements and identifies four suitable similarity measures. We validate our approach by demonstrating the increase in reliability for the data sets found in the survey.}, address = {New York, NY, USA}, author = {Leznik, Mark and Grohmann, Johannes and Kliche, Nina and Bauer, Andr{é} and Seybold, Daniel and Eismann, Simon and Kounev, Samuel and Domaschka, J{ö}rg}, booktitle = {Proceedings of the 2022 ACM/SPEC on International Conference on Performance Engineering}, keywords = {analysis descartes metrics t_short timeseries myown}, pages = {89–96}, publisher = {Association for Computing Machinery}, series = {ICPE '22}, title = {Same, Same, but Dissimilar: Exploring Measurements for Workload Time-Series Similarity}, year = 2022 }
33.
Seibt, S., von Ramon Lipinski, B., Latoschik, M.E.: Dense Feature Matching based on Homographic Decomposition. IEEE Access. X, 1–1 (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Finding robust and accurate feature matches is a fundamental problem in computer vision. However, incorrect correspondences and suboptimal matching accuracies lead to significant challenges for many real-world applications. In conventional feature matching, corresponding features in an image pair are greedily searched using their descriptor distance. The resulting matching set is then typically used as input for geometric model fitting methods to find an appropriate fundamental matrix and filter out incorrect matches. Unfortunately, this basic approach cannot solve all practical problems, such as fundamental matrix degeneration, matching ambiguities caused by repeated patterns and rejection of initially mismatched features without further reconsideration. In this paper we introduce a novel matching pipeline, which addresses all of the aforementioned challenges at once: First, we perform iterative rematching to give mismatched feature points a further chance for being considered in later processing steps. Thereby, we are searching for inliers that exhibit the same homographic transformation per iteration. The resulting homographic decomposition is used for refining matches, occlusion detection (e.g. due to parallaxes) and extrapolation of additional features in critical image areas. Furthermore, Delaunay triangulation of the matching set is utilized to minimize the repeated pattern problem and to implement focused matching. Doing so, enables us to further increase matching quality by concentrating on local image areas, defined by the triangular mesh. We present and discuss experimental results with multiple real-world matching datasets. Our contributions, besides improving matching recall and precision for image processing applications in general, also relate to use cases in image-based computer graphics.
@article{seibt2022dense, abstract = {Finding robust and accurate feature matches is a fundamental problem in computer vision. However, incorrect correspondences and suboptimal matching accuracies lead to significant challenges for many real-world applications. In conventional feature matching, corresponding features in an image pair are greedily searched using their descriptor distance. The resulting matching set is then typically used as input for geometric model fitting methods to find an appropriate fundamental matrix and filter out incorrect matches. Unfortunately, this basic approach cannot solve all practical problems, such as fundamental matrix degeneration, matching ambiguities caused by repeated patterns and rejection of initially mismatched features without further reconsideration. In this paper we introduce a novel matching pipeline, which addresses all of the aforementioned challenges at once: First, we perform iterative rematching to give mismatched feature points a further chance for being considered in later processing steps. Thereby, we are searching for inliers that exhibit the same homographic transformation per iteration. The resulting homographic decomposition is used for refining matches, occlusion detection (e.g. due to parallaxes) and extrapolation of additional features in critical image areas. Furthermore, Delaunay triangulation of the matching set is utilized to minimize the repeated pattern problem and to implement focused matching. Doing so, enables us to further increase matching quality by concentrating on local image areas, defined by the triangular mesh. We present and discuss experimental results with multiple real-world matching datasets. Our contributions, besides improving matching recall and precision for image processing applications in general, also relate to use cases in image-based computer graphics.}, author = {Seibt, Simon and von Ramon Lipinski, Bartosz and Latoschik, March Erich}, journal = {IEEE Access}, keywords = {latoschik myown}, pages = {1-1}, title = {Dense Feature Matching based on Homographic Decomposition}, volume = {X}, year = 2022 }
34.
Wienrich, C., Fries, L., Latoschik, M.E.: Remote at Court – Challenges and Solutions of Video Conferencing in the Judicial System. Proceedings 25th HCI International Conference. Springer (2022).
[ BibTeX ]
 
@inproceedings{wienrich2022remote, author = {Wienrich, Carolin and Fries, Lennart and Latoschik, Marc Erich}, booktitle = {Proceedings 25th HCI International Conference}, keywords = {hci-uwb myown}, note = {to appear}, publisher = {Springer}, title = {Remote at Court – Challenges and Solutions of Video Conferencing in the Judicial System}, volume = {Design, Operation and Evaluation of Mobile Communications}, year = 2022 }
35.
Chaplick, S., Felsner, S., Kindermann, P., Klawitter, J., Rutter, I., Wolff, A.: Simple Algorithms for Partial and Simultaneous Rectangular Duals with Given Contact Orientations. Theoretical Computer Science. (2022).
[ Abstract ] [ BibTeX ] [ DOI ]
 
A rectangular dual of a graph \($G$\) is a contact representation of \($G$\) by axis-aligned rectangles such that (i) no four rectangles share a point and (ii) the union of all rectangles is a rectangle. The emphpartial representation extension problem for rectangular duals asks whether a given partial rectangular dual can be extended to a rectangular dual, that is, whether there exists a rectangular dual where some vertices are represented by prescribed rectangles. The emphsimultaneous representation problem for rectangular duals asks whether two (or more) given graphs that share a subgraph admit rectangular duals that coincide on the shared subgraph. Combinatorially, a rectangular dual can be described by a regular edge labeling (REL), which determines the orientations of the rectangle contacts. par We describe linear-time algorithms for the partial representation extension problem and the simultaneous representation problem for rectangular duals when each input graph is given together with a REL. Both algorithms are based on formulations as linear programs, yet they have geometric interpretations and can be seen as extensions of the classic algorithm by Kant and He that computes a rectangular dual for a given graph.
@article{cfkkrw-sapsr-TCS22, abstract = {A rectangular dual of a graph $G$ is a contact representation of $G$ by axis-aligned rectangles such that (i) no four rectangles share a point and (ii) the union of all rectangles is a rectangle. The \emph{partial representation extension problem} for rectangular duals asks whether a given partial rectangular dual can be extended to a rectangular dual, that is, whether there exists a rectangular dual where some vertices are represented by prescribed rectangles. The \emph{simultaneous representation problem} for rectangular duals asks whether two (or more) given graphs that share a subgraph admit rectangular duals that coincide on the shared subgraph. Combinatorially, a rectangular dual can be described by a regular edge labeling (REL), which determines the orientations of the rectangle contacts. \par We describe linear-time algorithms for the partial representation extension problem and the simultaneous representation problem for rectangular duals when each input graph is given together with a REL. Both algorithms are based on formulations as linear programs, yet they have geometric interpretations and can be seen as extensions of the classic algorithm by Kant and He that computes a rectangular dual for a given graph.}, author = {Chaplick, Steven and Felsner, Stefan and Kindermann, Philipp and Klawitter, Jonathan and Rutter, Ignaz and Wolff, Alexander}, journal = {Theoretical Computer Science}, keywords = {myown partial_representation_extension rectangular_dual simultaneous_representation}, title = {Simple Algorithms for Partial and Simultaneous Rectangular Duals with Given Contact Orientations}, year = 2022 }
36.
Straesser, M., Grohmann, J., von Kistowski, J., Eismann, S., Bauer, A., Kounev, S.: Why Is It Not Solved Yet? Challenges for Production-Ready Autoscaling. Proceedings of the 2022 ACM/SPEC on International Conference on Performance Engineering. S. 105–115. Association for Computing Machinery, New York, NY, USA (2022).
[ Abstract ] [ BibTeX ] [ URL ]
 
Autoscaling is a task of major importance in the cloud computing domain as it directly affects both operating costs and customer experience. Although there has been active research in this area for over ten years now, there is still a significant gap between the proposed methods in the literature and the deployed autoscalers in practice. Hence, many research autoscalers do not find their way into production deployments. This paper describes six core challenges that arise in production systems that are still not solved by most research autoscalers. We illustrate these problems through experiments in a realistic cloud environment with a real-world multi-service business application and show that commonly used autoscalers have various shortcomings. In addition, we analyze the behavior of overloaded services and show that these can be problematic for existing autoscalers. Generally, we analyze that these challenges are only insufficiently addressed in the literature and conclude that future scaling approaches should focus on the needs of production systems.
@inproceedings{10.1145/3489525.3511680, abstract = {Autoscaling is a task of major importance in the cloud computing domain as it directly affects both operating costs and customer experience. Although there has been active research in this area for over ten years now, there is still a significant gap between the proposed methods in the literature and the deployed autoscalers in practice. Hence, many research autoscalers do not find their way into production deployments. This paper describes six core challenges that arise in production systems that are still not solved by most research autoscalers. We illustrate these problems through experiments in a realistic cloud environment with a real-world multi-service business application and show that commonly used autoscalers have various shortcomings. In addition, we analyze the behavior of overloaded services and show that these can be problematic for existing autoscalers. Generally, we analyze that these challenges are only insufficiently addressed in the literature and conclude that future scaling approaches should focus on the needs of production systems.}, address = {New York, NY, USA}, author = {Straesser, Martin and Grohmann, Johannes and von Kistowski, J{ó}akim and Eismann, Simon and Bauer, Andr{é} and Kounev, Samuel}, booktitle = {Proceedings of the 2022 ACM/SPEC on International Conference on Performance Engineering}, keywords = {autoscaling cloud_computing descartes microservices t_full myown}, pages = {105–115}, publisher = {Association for Computing Machinery}, series = {ICPE '22}, title = {Why Is It Not Solved Yet? Challenges for Production-Ready Autoscaling}, year = 2022 }
37.
und David Schantz und Julian Gröh und Andreas Knote und Prof. Dr. Sebastian von Mammen und Prof. Dr. Juliano Cabral, A.L.: bioDIVERsity. Ein Computerspiel gegen das Imageproblem von Wasserpflanzen. Mitteilungen der Fränkischen Geographischen Gesellschaft. 29–36 (2022).
[ Abstract ] [ BibTeX ] [ URL ]
 
Wasserpflanzen haben ein Imageproblem: Sie stören vermeintlich beim Baden in Seen, was zu panikartigenReaktionen führen kann. Begriffe wie „Schlingpflanzen“ und „Veralgung“ werden falsch verwendet odersind negativ konnotiert. Zudem sieht man Wasserpflanzen kaum, da sie überwiegend unter der Wasseroberflächewachsen. Ihre vielen wertvollen Funktionen im Ökosystem See bleiben daher oft unerkannt undsind durch die schlechte Erreichbarkeit und Erfahrbarkeit nur schwer zu vermitteln.Virtuelle Medien eröffnen eine neue Möglichkeit, schwierig erreichbare Orte erfahrbar zu machen. Fürdie Vermittlung von Umweltthemen – gerade an eine jüngere Zielgruppe – wird ein großes Potential indigitalen Spielen und Simulationen (Computerspiele, Apps, Virtual Reality-Spiele), speziell sogenanntenSerious Games, gesehen.Ein Prototyp für das Serious Game bioDIVERsity wurde im Rahmen eines interdisziplinären Kurses derArbeitsgruppe Games Engineering am Institut für Informatik in Zusammenarbeit mit dem Center for Computationaland Theoretical Biology an der Universität Würzburg entwickelt. Ziel des Spiels ist es, KindernKenntnisse über das Ökosystem See und die Auswirkungen der Wasserqualität und der Klimabedingungenauf Wasserpflanzen zu vermitteln. Darüber hinaus soll ein Bewusstsein für dieses Ökosystem und die Auswirkungenmenschlicher Eingriffe entstehen.
@article{Lewerentz:2022aa, abstract = {Wasserpflanzen haben ein Imageproblem: Sie stören vermeintlich beim Baden in Seen, was zu panikartigenReaktionen führen kann. Begriffe wie „Schlingpflanzen“ und „Veralgung“ werden falsch verwendet odersind negativ konnotiert. Zudem sieht man Wasserpflanzen kaum, da sie überwiegend unter der Wasseroberflächewachsen. Ihre vielen wertvollen Funktionen im Ökosystem See bleiben daher oft unerkannt undsind durch die schlechte Erreichbarkeit und Erfahrbarkeit nur schwer zu vermitteln.Virtuelle Medien eröffnen eine neue Möglichkeit, schwierig erreichbare Orte erfahrbar zu machen. Fürdie Vermittlung von Umweltthemen – gerade an eine jüngere Zielgruppe – wird ein großes Potential indigitalen Spielen und Simulationen (Computerspiele, Apps, Virtual Reality-Spiele), speziell sogenanntenSerious Games, gesehen.Ein Prototyp für das Serious Game bioDIVERsity wurde im Rahmen eines interdisziplinären Kurses derArbeitsgruppe Games Engineering am Institut für Informatik in Zusammenarbeit mit dem Center for Computationaland Theoretical Biology an der Universität Würzburg entwickelt. Ziel des Spiels ist es, KindernKenntnisse über das Ökosystem See und die Auswirkungen der Wasserqualität und der Klimabedingungenauf Wasserpflanzen zu vermitteln. Darüber hinaus soll ein Bewusstsein für dieses Ökosystem und die Auswirkungenmenschlicher Eingriffe entstehen.}, author = {und David Schantz und Julian Gröh und Andreas Knote und Prof. Dr. Sebastian von Mammen und Prof. Dr. Juliano Cabral, Anne Lewerentz}, journal = {Mitteilungen der Fränkischen Geographischen Gesellschaft}, keywords = {imported myown}, number = 67, pages = {29–36}, title = {bioDIVERsity. Ein Computerspiel gegen das Imageproblem von Wasserpflanzen}, year = 2022 }
38.
Eismann, S., Costa, D., Liao, L., Bezemer, C.-P., Shang, W., van Hoorn, A., Kounev, S.: A case study on the stability of performance tests for serverless applications. Journal of Systems and Software (JSS). 189, (2022).
[ Abstract ] [ BibTeX ] [ URL ]
 
Context: While in serverless computing, application resource management and operational concerns are generally delegated to the cloud provider, ensuring that serverless applications meet their performance requirements is still a responsibility of the developers. Performance testing is a commonly used performance assessment practice; however, it traditionally requires visibility of the resource environment. Objective: In this study, we investigate whether performance tests of serverless applications are stable, that is, if their results are reproducible, and what implications the serverless paradigm has for performance tests. Method: We conduct a case study where we collect two datasets of performance test results: (a) repetitions of performance tests for varying memory size and load intensities and (b) three repetitions of the same performance test every day for ten months. Results: We find that performance tests of serverless applications are comparatively stable if conducted on the same day. However, we also observe short-term performance variations and frequent long-term performance changes. Conclusion: Performance tests for serverless applications can be stable; however, the serverless model impacts the planning, execution, and analysis of performance tests.
@article{eismann2022study, abstract = {Context: While in serverless computing, application resource management and operational concerns are generally delegated to the cloud provider, ensuring that serverless applications meet their performance requirements is still a responsibility of the developers. Performance testing is a commonly used performance assessment practice; however, it traditionally requires visibility of the resource environment. Objective: In this study, we investigate whether performance tests of serverless applications are stable, that is, if their results are reproducible, and what implications the serverless paradigm has for performance tests. Method: We conduct a case study where we collect two datasets of performance test results: (a) repetitions of performance tests for varying memory size and load intensities and (b) three repetitions of the same performance test every day for ten months. Results: We find that performance tests of serverless applications are comparatively stable if conducted on the same day. However, we also observe short-term performance variations and frequent long-term performance changes. Conclusion: Performance tests for serverless applications can be stable; however, the serverless model impacts the planning, execution, and analysis of performance tests.}, author = {Eismann, Simon and Costa, Diego and Liao, Lizhi and Bezemer, Cor-Paul and Shang, Weiyi and van Hoorn, André and Kounev, Samuel}, journal = {Journal of Systems and Software (JSS)}, keywords = {descartes t_journalmagazine myown}, title = {A case study on the stability of performance tests for serverless applications}, volume = 189, year = 2022 }
39.
Döllinger, N., Wolf, E., Mal, D., Erdmannsdörfer, N., Botsch, M., Latoschik, M.E., Wienrich, C.: Virtual Reality for Mind and Body: Does the Sense of Embodiment Towards a Virtual Body Affect Physical Body Awareness?. CHI 22 Conference on Human Factors in Computing Systems Extended Abstracts. S. 7 (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Mind-body therapies aim to improve health by combining physical and mental exercises. Recent developments tend to incorporate virtual reality (VR) into their design and execution, but there is a lack of research concerning the inclusion of virtual bodies and their effect on body awareness in these designs. In this study, 24 participants performed in-VR body awareness movement tasks in front of a virtual mirror while embodying a photorealistic, personalized avatar. Subsequently, they performed a heartbeat counting task and rated their perceived body awareness and sense of embodiment towards the avatar. We found a significant relationship between sense of embodiment and self-reported body awareness but not between sense of embodiment and heartbeat counting. Future work can build on these findings and further explore the relationship between avatar embodiment and body awareness.
@inproceedings{dollinger2022virtual, abstract = {Mind-body therapies aim to improve health by combining physical and mental exercises. Recent developments tend to incorporate virtual reality (VR) into their design and execution, but there is a lack of research concerning the inclusion of virtual bodies and their effect on body awareness in these designs. In this study, 24 participants performed in-VR body awareness movement tasks in front of a virtual mirror while embodying a photorealistic, personalized avatar. Subsequently, they performed a heartbeat counting task and rated their perceived body awareness and sense of embodiment towards the avatar. We found a significant relationship between sense of embodiment and self-reported body awareness but not between sense of embodiment and heartbeat counting. Future work can build on these findings and further explore the relationship between avatar embodiment and body awareness.}, author = {Döllinger, Nina and Wolf, Erik and Mal, David and Erdmannsdörfer, Nico and Botsch, Mario and Latoschik, Marc Erich and Wienrich, Carolin}, journal = {CHI 22 Conference on Human Factors in Computing Systems Extended Abstracts}, keywords = {dmal ewolf myown}, month = {April}, pages = 7, title = {Virtual Reality for Mind and Body: Does the Sense of Embodiment Towards a Virtual Body Affect Physical Body Awareness?}, year = 2022 }
40.
Raffeck, S., Geißler, S., Krolikowski, M., Gebert, S., Hoßfeld, T.: Data Usage in IoT: A Characterization of GTP Tunnels in M2M Mobile Networks. 2nd IFIP/IEEE International workshop on Fully-Flexible Internet Architectures and Protocols for the Next-Generation Tactile Internet (FlexNGIA) (2022).
[ Abstract ] [ BibTeX ]
 
IoT and M2M devices have seen a significant growth in usage and deployment over the last years. Gaining insight into device and data usage behavior exhibited by the participants of mobile networks is elementary for MNO and MVNO to scale their networks and provide a reliable service. This work aims to make use of its first of a kind dataset, spanning multiple countries and MNO, to provide a detailed characterization of GTP tunnels and devices. To this end, general statistics are used to describe the observed data traffic focusing on the distribution of the tunnel duration and volume as well as periodic device behavior. An approximate metric is introduced to analyze the periodicity and synchronicity of IoT devices. Lastly, we publish the data investigated in this work and provide a large scale dataset on the data usage behavior of IoT devices to interested researchers.
@inproceedings{info3-inproceedings-2022-5, abstract = {IoT and M2M devices have seen a significant growth in usage and deployment over the last years. Gaining insight into device and data usage behavior exhibited by the participants of mobile networks is elementary for MNO and MVNO to scale their networks and provide a reliable service. This work aims to make use of its first of a kind dataset, spanning multiple countries and MNO, to provide a detailed characterization of GTP tunnels and devices. To this end, general statistics are used to describe the observed data traffic focusing on the distribution of the tunnel duration and volume as well as periodic device behavior. An approximate metric is introduced to analyze the periodicity and synchronicity of IoT devices. Lastly, we publish the data investigated in this work and provide a large scale dataset on the data usage behavior of IoT devices to interested researchers.}, author = {Raffeck, Simon and Geißler, Stefan and Krolikowski, Michael and Gebert, Steffen and Hoßfeld, Tobias}, booktitle = {2nd IFIP/IEEE International workshop on Fully-Flexible Internet Architectures and Protocols for the Next-Generation Tactile Internet (FlexNGIA)}, keywords = {myown 5cale can}, month = 4, title = {Data Usage in IoT: A Characterization of GTP Tunnels in M2M Mobile Networks}, year = 2022 }
41.
Vomhoff, V., Geißler, S., Loh, F., Bauer, W., Hoßfeld, T.: Characterizing Mobile Signaling Anomalies in the Internet-of-Things. 2nd IFIP/IEEE International workshop on Fully-Flexible Internet Architectures and Protocols for the Next-Generation Tactile Internet (FlexNGIA) (2022).
[ Abstract ] [ BibTeX ]
 
The development and adoption speed of new Internet of Things (IoT) devices and applications is constantly increasing. In particular in mobile networks, however, constant connectivity for all newly developed, globally spread, and occasionally geographically mobile devices is challenging. While the main business of current network operators is in particular, not to roam these new device generation between different networks, whereas new so-called Mobile Virtual Network Operators (MVNOs) arise with exactly this business case. They use already available Radio Access Networks and deploy SIM cards that are able to establish data connection everywhere on the basis of international roaming agreements. However, because of the complex interconnection of different systems, additional challenges arise. Outages in one network component might impact the whole system. In this work, we study these signaling anomalies called incidents based on a dataset received from a global MVNO. The goal of this work is to determine traffic characteristics during these incidents towards a better understanding of signaling traffic in IoT networks. Thus, this work can be seen as a fundamental basis to help operators in a characterization, and in particular prediction and avoidance of signaling incidents.
@inproceedings{info3-inproceedings-2022-4, abstract = {The development and adoption speed of new Internet of Things (IoT) devices and applications is constantly increasing. In particular in mobile networks, however, constant connectivity for all newly developed, globally spread, and occasionally geographically mobile devices is challenging. While the main business of current network operators is in particular, not to roam these new device generation between different networks, whereas new so-called Mobile Virtual Network Operators (MVNOs) arise with exactly this business case. They use already available Radio Access Networks and deploy SIM cards that are able to establish data connection everywhere on the basis of international roaming agreements. However, because of the complex interconnection of different systems, additional challenges arise. Outages in one network component might impact the whole system. In this work, we study these signaling anomalies called incidents based on a dataset received from a global MVNO. The goal of this work is to determine traffic characteristics during these incidents towards a better understanding of signaling traffic in IoT networks. Thus, this work can be seen as a fundamental basis to help operators in a characterization, and in particular prediction and avoidance of signaling incidents.}, author = {Vomhoff, Viktoria and Geißler, Stefan and Loh, Frank and Bauer, Wolfgang and Hoßfeld, Tobias}, booktitle = {2nd IFIP/IEEE International workshop on Fully-Flexible Internet Architectures and Protocols for the Next-Generation Tactile Internet (FlexNGIA)}, keywords = {myown 5cale can}, month = 4, title = {Characterizing Mobile Signaling Anomalies in the Internet-of-Things}, year = 2022 }
42.
Loh, F., Mehling, N., Geißler, S., Hoßfeld, T.: Simulative Performance Study of Slotted Aloha for LoRaWAN Channel Access. IEEE/IFIP Network Operations and Management Symposium (2022).
[ Abstract ] [ BibTeX ]
 
Future Internet of Things deployments generate a multitude of new challenges and opportunities. While 5G networks promise massive throughput rates with ultra low delays, many verticals in the areas of Industry 4.0, Smart City, or Smart Agriculture only transmit tiny amounts of data and instead demand high energy efficiency. This is addressed by access technologies like Low Power Wide Area Networks being com- plementary to high performance 5G networks. Especially Long Range Wide Area Network (LoRaWAN) promises transmissions across long distances with low energy requirements with the drawback of unreliable transmission due to potential message collisions through random channel access. For that reason, a broad parameter study simulation for LoRaWAN channel access with slotted Aloha is presented for real world scenarios and influences like clock drifts or cross traffic. The key impact factors of this channel access approach are studied with focus on the collision probability in various scenarios and simulation results are compared to the current state of the art. The contribution of this work are guidelines for parameter settings in a LoRaWAN with slotted Aloha channel access and performance comparisons for different settings. This information is crucial to scale and operate future LoRaWANs.
@inproceedings{info3-article-2022-13, abstract = {Future Internet of Things deployments generate a multitude of new challenges and opportunities. While 5G networks promise massive throughput rates with ultra low delays, many verticals in the areas of Industry 4.0, Smart City, or Smart Agriculture only transmit tiny amounts of data and instead demand high energy efficiency. This is addressed by access technologies like Low Power Wide Area Networks being com- plementary to high performance 5G networks. Especially Long Range Wide Area Network (LoRaWAN) promises transmissions across long distances with low energy requirements with the drawback of unreliable transmission due to potential message collisions through random channel access. For that reason, a broad parameter study simulation for LoRaWAN channel access with slotted Aloha is presented for real world scenarios and influences like clock drifts or cross traffic. The key impact factors of this channel access approach are studied with focus on the collision probability in various scenarios and simulation results are compared to the current state of the art. The contribution of this work are guidelines for parameter settings in a LoRaWAN with slotted Aloha channel access and performance comparisons for different settings. This information is crucial to scale and operate future LoRaWANs.}, author = {Loh, Frank and Mehling, Noah and Geißler, Stefan and Hoßfeld, Tobias}, booktitle = {IEEE/IFIP Network Operations and Management Symposium}, keywords = {myown 5mart can}, month = 4, title = {Simulative Performance Study of Slotted Aloha for LoRaWAN Channel Access}, year = 2022 }
43.
Loh, F., Mehling, N., Hoßfeld, T.: Towards LoRaWAN without Data Loss: Studying the Performance of Different Channel Access Approaches. Sensors. (2022).
[ Abstract ] [ BibTeX ]
 
The Long Range Wide Area Network (LoRaWAN) is one of the fastest growing Internet of Things (IoT) access protocols. It operates in the license free 868 MHz band and gives everyone the possibility to create their own small sensor networks. The drawback of this technology is often unscheduled or random channel access, which leads to message collisions and potential data loss. For that reason, recent literature studies alternative approaches for LoRaWAN channel access. In this work, state-of-the-art random channel access is compared with alternative approaches from the litera- ture by means of collision probability. Furthermore, a time scheduled channel access methodology is presented to completely avoid collisions in LoRaWAN. For this approach, an exhaustive simulation study was conducted and the performance was evaluated with random access cross-traffic. In a general theoretical analysis the limits of the time scheduled approach are discussed to comply with duty cycle regulations in LoRaWAN.
@article{info3-inproceedings-2022-3, abstract = {The Long Range Wide Area Network (LoRaWAN) is one of the fastest growing Internet of Things (IoT) access protocols. It operates in the license free 868 MHz band and gives everyone the possibility to create their own small sensor networks. The drawback of this technology is often unscheduled or random channel access, which leads to message collisions and potential data loss. For that reason, recent literature studies alternative approaches for LoRaWAN channel access. In this work, state-of-the-art random channel access is compared with alternative approaches from the litera- ture by means of collision probability. Furthermore, a time scheduled channel access methodology is presented to completely avoid collisions in LoRaWAN. For this approach, an exhaustive simulation study was conducted and the performance was evaluated with random access cross-traffic. In a general theoretical analysis the limits of the time scheduled approach are discussed to comply with duty cycle regulations in LoRaWAN.}, author = {Loh, Frank and Mehling, Noah and Hoßfeld, Tobias}, journal = {Sensors}, keywords = {myown 5mart}, month = 1, title = {Towards LoRaWAN without Data Loss: Studying the Performance of Different Channel Access Approaches}, year = 2022 }
44.
Palmisano, C., Kullmann, P., Hanafi, I., Verrecchia, M., Latoschik, M.E., Canessa, A., Fischbach, M., Isaias, I.U.: A Fully-Immersive Virtual Reality Setup to Study Gait Modulation. Frontiers in Human Neuroscience. 16, (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Objective: Gait adaptation to environmental challenges is fundamental for independent and safe community ambulation. The possibility of precisely studying gait modulation using standardized protocols of gait analysis closely resembling everyday life scenarios is still an unmet need.Methods: We have developed a fully-immersive virtual reality (VR) environment where subjects have to adjust their walking pattern to avoid collision with a virtual agent (VA) crossing their gait trajectory. We collected kinematic data of 12 healthy young subjects walking in real world (RW) and in the VR environment, both with (VR/A+) and without (VR/A-) the VA perturbation. The VR environment closely resembled the RW scenario of the gait laboratory. To ensure standardization of the obstacle presentation the starting time speed and trajectory of the VA were defined using the kinematics of the participant as detected online during each walking trial.Results: We did not observe kinematic differences between walking in RW and VR/A-, suggesting that our VR environment per se might not induce significant changes in the locomotor pattern. When facing the VA all subjects consistently reduced stride length and velocity while increasing stride duration. Trunk inclination and mediolateral trajectory deviation also facilitated avoidance of the obstacle.Conclusions: This proof-of-concept study shows that our VR/A+ paradigm effectively induced a timely gait modulation in a standardized immersive and realistic scenario. This protocol could be a powerful research tool to study gait modulation and its derangements in relation to aging and clinical conditions.
@article{10.3389/fnhum.2022.783452, abstract = {Objective: Gait adaptation to environmental challenges is fundamental for independent and safe community ambulation. The possibility of precisely studying gait modulation using standardized protocols of gait analysis closely resembling everyday life scenarios is still an unmet need.Methods: We have developed a fully-immersive virtual reality (VR) environment where subjects have to adjust their walking pattern to avoid collision with a virtual agent (VA) crossing their gait trajectory. We collected kinematic data of 12 healthy young subjects walking in real world (RW) and in the VR environment, both with (VR/A+) and without (VR/A-) the VA perturbation. The VR environment closely resembled the RW scenario of the gait laboratory. To ensure standardization of the obstacle presentation the starting time speed and trajectory of the VA were defined using the kinematics of the participant as detected online during each walking trial.Results: We did not observe kinematic differences between walking in RW and VR/A-, suggesting that our VR environment per se might not induce significant changes in the locomotor pattern. When facing the VA all subjects consistently reduced stride length and velocity while increasing stride duration. Trunk inclination and mediolateral trajectory deviation also facilitated avoidance of the obstacle.Conclusions: This proof-of-concept study shows that our VR/A+ paradigm effectively induced a timely gait modulation in a standardized immersive and realistic scenario. This protocol could be a powerful research tool to study gait modulation and its derangements in relation to aging and clinical conditions.}, author = {Palmisano, Chiara and Kullmann, Peter and Hanafi, Ibrahem and Verrecchia, Marta and Latoschik, Marc Erich and Canessa, Andrea and Fischbach, Martin and Isaias, Ioannis Ugo}, journal = {Frontiers in Human Neuroscience}, keywords = {hci-uwb myown}, title = {A Fully-Immersive Virtual Reality Setup to Study Gait Modulation}, volume = 16, year = 2022 }
45.
Halbig, A., Babu, S.K., Gatter, S., Latoschik, M.E., Brukamp, K., von Mammen, S.: Opportunities and Challenges of Virtual Reality in Healthcare – A Domain Experts Inquiry. Frontiers in Virtual Reality. 3, (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
In recent years, the applications and accessibility of Virtual Reality (VR) for the healthcare sector have continued to grow. However, so far, most VR applications are only relevant in research settings. Information about what healthcare professionals would need to independently integrate VR applications into their daily working routines is missing. The actual needs and concerns of the people who work in the healthcare sector are often disregarded in the development of VR applications, even though they are the ones who are supposed to use them in practice. By means of this study, we systematically involve health professionals in the development process of VR applications. In particular, we conducted an online survey with 102 healthcare professionals based on a video prototype which demonstrates a software platform that allows them to create and utilise VR experiences on their own. For this study, we adapted and extended the Technology Acceptance Model (TAM). The survey focused on the perceived usefulness and the ease of use of such a platform, as well as the attitude and ethical concerns the users might have. The results show a generally positive attitude toward such a software platform. The users can imagine various use cases in different health domains. However, the perceived usefulness is tied to the actual ease of use of the platform and sufficient support for learning and working with the platform. In the discussion, we explain how these results can be generalized to facilitate the integration of VR in healthcare practice.
@article{halbig:2022q, abstract = {In recent years, the applications and accessibility of Virtual Reality (VR) for the healthcare sector have continued to grow. However, so far, most VR applications are only relevant in research settings. Information about what healthcare professionals would need to independently integrate VR applications into their daily working routines is missing. The actual needs and concerns of the people who work in the healthcare sector are often disregarded in the development of VR applications, even though they are the ones who are supposed to use them in practice. By means of this study, we systematically involve health professionals in the development process of VR applications. In particular, we conducted an online survey with 102 healthcare professionals based on a video prototype which demonstrates a software platform that allows them to create and utilise VR experiences on their own. For this study, we adapted and extended the Technology Acceptance Model (TAM). The survey focused on the perceived usefulness and the ease of use of such a platform, as well as the attitude and ethical concerns the users might have. The results show a generally positive attitude toward such a software platform. The users can imagine various use cases in different health domains. However, the perceived usefulness is tied to the actual ease of use of the platform and sufficient support for learning and working with the platform. In the discussion, we explain how these results can be generalized to facilitate the integration of VR in healthcare practice.}, author = {Halbig, Andreas and Babu, Sooraj K. and Gatter, Shirin and Latoschik, Marc Erich and Brukamp, Kirsten and von Mammen, Sebastian}, journal = {Frontiers in Virtual Reality}, keywords = {hci-uwb myown via-vr}, title = {Opportunities and Challenges of Virtual Reality in Healthcare – A Domain Experts Inquiry}, volume = 3, year = 2022 }
46.
Hein, R.M., Latoschik, M.E., Wienrich, C.: Inter- and Transcultural Learning in Social Virtual Reality: A Proposal for an Inter- and Transcultural Virtual Object Database to be Used in the Implementation, Reflection, and Evaluation of Virtual Encounters. Multimodal Technologies and Interaction. 6, 50 (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Visual stimuli are frequently used to improve memory, language learning or perception, and understanding of metacognitive processes. However, in virtual reality (VR), there are few systematically and empirically derived databases. This paper proposes the first collection of virtual objects based on empirical evaluation for inter-and transcultural encounters between English- and German-speaking learners. We used explicit and implicit measurement methods to identify cultural associations and the degree of stereotypical perception for each virtual stimuli (n = 293) through two online studies, including native German and English-speaking participants. The analysis resulted in a final well-describable database of 128 objects (called InteractionSuitcase). In future applications, the objects can be used as a great interaction or conversation asset and behavioral measurement tool in social VR applications, especially in the field of foreign language education. For example, encounters can use the objects to describe their culture, or teachers can intuitively assess stereotyped attitudes of the encounters.
@article{mti6070050, abstract = {Visual stimuli are frequently used to improve memory, language learning or perception, and understanding of metacognitive processes. However, in virtual reality (VR), there are few systematically and empirically derived databases. This paper proposes the first collection of virtual objects based on empirical evaluation for inter-and transcultural encounters between English- and German-speaking learners. We used explicit and implicit measurement methods to identify cultural associations and the degree of stereotypical perception for each virtual stimuli (n = 293) through two online studies, including native German and English-speaking participants. The analysis resulted in a final well-describable database of 128 objects (called InteractionSuitcase). In future applications, the objects can be used as a great interaction or conversation asset and behavioral measurement tool in social VR applications, especially in the field of foreign language education. For example, encounters can use the objects to describe their culture, or teachers can intuitively assess stereotyped attitudes of the encounters.}, author = {Hein, Rebecca M. and Latoschik, Marc Erich and Wienrich, Carolin}, editor = {{Mark Billinghurst, Fotis Liarokapis}, Lars Erik Holmquist and Su, Mu-Chun}, journal = {Multimodal Technologies and Interaction}, keywords = {c.wienrich coteach hci-uwb myown rebecca.hein rhein}, number = 7, pages = 50, title = {Inter- and Transcultural Learning in Social Virtual Reality: A Proposal for an Inter- and Transcultural Virtual Object Database to be Used in the Implementation, Reflection, and Evaluation of Virtual Encounters}, volume = 6, year = 2022 }
47.
Donnermann, M., Schaper, P., Lugrin, B.: Social Robots in Applied Settings: A Long-Term Study on Adaptive Robotic Tutors in Higher Education. Frontiers in Robotics and AI. 9, (2022).
[ BibTeX ] [ URL ] [ DOI ]
 
@article{Donnermann_2022, author = {Donnermann, Melissa and Schaper, Philipp and Lugrin, Birgit}, journal = {Frontiers in Robotics and AI}, keywords = {birgit donnermann learning mi myown schaper}, publisher = {Frontiers Media SA}, title = {Social Robots in Applied Settings: A Long-Term Study on Adaptive Robotic Tutors in Higher Education}, volume = 9, year = 2022 }
48.
Döllinger, N., Wolf, E., Mal, D., Wenninger, S., Botsch, M., Latoschik, M.E., Wienrich, C.: Resize Me! Exploring the User Experience of Embodied Realistic Modulatable Avatars for Body Image Intervention in Virtual Reality. arXiv preprint arXiv:2203.05060. (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Obesity is a serious disease that can affect both physical and psychological well-being. Due to weight stigmatization, many affected individuals suffer from body image disturbances whereby they perceive their body in a distorted way, evaluate it negatively, or neglect it. Beyond established interventions such as mirror exposure, recent advancements aim to complement body image treatments by the embodiment of visually altered virtual bodies in virtual reality (VR). We present a high-fidelity prototype of an advanced VR system that allows users to embody a rapidly generated personalized, photorealistic avatar and to realistically modulate its body weight in real-time within a carefully designed virtual environment. In a formative multi-method approach, a total of 12 participants rated the general user experience (UX) of our system during body scan and VR experience using semi-structured qualitative interviews and multiple quantitative UX measures. By using body weight modification tasks, we further compared three different interaction methods for real-time body weight modification and measured our system's impact on the body image relevant measures body awareness and body weight perception. From the feedback received, demonstrating an already solid UX of our overall system and providing constructive input for further improvement, we derived a set of design guidelines to guide future development and evaluation processes of systems supporting body image interventions.
@article{dollinger2022resize, abstract = {Obesity is a serious disease that can affect both physical and psychological well-being. Due to weight stigmatization, many affected individuals suffer from body image disturbances whereby they perceive their body in a distorted way, evaluate it negatively, or neglect it. Beyond established interventions such as mirror exposure, recent advancements aim to complement body image treatments by the embodiment of visually altered virtual bodies in virtual reality (VR). We present a high-fidelity prototype of an advanced VR system that allows users to embody a rapidly generated personalized, photorealistic avatar and to realistically modulate its body weight in real-time within a carefully designed virtual environment. In a formative multi-method approach, a total of 12 participants rated the general user experience (UX) of our system during body scan and VR experience using semi-structured qualitative interviews and multiple quantitative UX measures. By using body weight modification tasks, we further compared three different interaction methods for real-time body weight modification and measured our system's impact on the body image relevant measures body awareness and body weight perception. From the feedback received, demonstrating an already solid UX of our overall system and providing constructive input for further improvement, we derived a set of design guidelines to guide future development and evaluation processes of systems supporting body image interventions.}, author = {Döllinger, Nina and Wolf, Erik and Mal, David and Wenninger, Stephan and Botsch, Mario and Latoschik, Marc Erich and Wienrich, Carolin}, journal = {arXiv preprint arXiv:2203.05060}, keywords = {dmal ewolf myown vitras}, title = {Resize Me! Exploring the User Experience of Embodied Realistic Modulatable Avatars for Body Image Intervention in Virtual Reality}, year = 2022 }
49.
Kindermann, P., Sauer, J., Wolff, A.: The Computational Complexity of the ChordLink Model. In: Di Giacomo, E. und Montecchiani, F. (hrsg.) Proc. 38th Europ. Workshop Comput. Geom. (EuroCG’22). S. 10:1–7 (2022).
[ BibTeX ]
 
@inproceedings{ksw-cccm-EuroCG22, author = {Kindermann, Philipp and Sauer, Jan and Wolff, Alexander}, booktitle = {Proc. 38th Europ. Workshop Comput. Geom. (EuroCG'22)}, editor = {{Di Giacomo}, Emilio and Montecchiani, Fabrizio}, keywords = {myown}, pages = {10:1–7}, title = {The Computational Complexity of the {ChordLink} Model}, year = 2022 }
50.
Kounev, S., van Hoorn, A., Straesser, M., Bauer, A.: SPEC Research Group Newsletter, Issue 11, (2022).
[ BibTeX ]
 
@misc{SPEC-RG-NEWSLETTER-11, author = {Kounev, Samuel and van Hoorn, Andre and Straesser, Martin and Bauer, Andr{é}}, keywords = {SPEC descartes t_other myown}, month = {April}, note = {Published by Standard Performance Evaluation Corporation (SPEC)}, title = {SPEC Research Group Newsletter, Issue 11}, year = 2022 }
51.
Brübach, L., Westermeier, F., Wienrich, C., Latoschik, M.E.: Breaking Plausibility Without Breaking Presence - Evidence For The Multi-Layer Nature Of Plausibility. IEEE Transactions on Visualization and Computer Graphics. 1–1 (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
A novel theoretical model recently introduced coherence and plausibility as the essential conditions of XR experiences, challenging contemporary presence-oriented concepts. This article reports on two experiments validating this model, which assumes coherence activation on three layers (cognition, perception, and sensation) as the potential sources leading to a condition of plausibility and from there to other XR qualia such as presence or body ownership. The experiments introduce and utilize breaks in plausibility (in analogy to breaks in presence): We induce incoherence on the perceptual and the cognitive layer simultaneously by a simulation of object behaviors that do not conform to the laws of physics, i.e., gravity. We show that this manipulation breaks plausibility and hence confirm that it results in the desired effects in the theorized condition space but that the breaks in plausibility did not affect presence. In addition, we show that a cognitive manipulation by a storyline framing is too weak to successfully counteract the strong bottom-up inconsistencies. Both results are in line with the predictions of the recently introduced three-layer model of coherence and plausibility, which incorporates well-known top-down and bottom-up rivalries and its theorized increased independence between plausibility and presence.
@article{9714117, abstract = {A novel theoretical model recently introduced coherence and plausibility as the essential conditions of XR experiences, challenging contemporary presence-oriented concepts. This article reports on two experiments validating this model, which assumes coherence activation on three layers (cognition, perception, and sensation) as the potential sources leading to a condition of plausibility and from there to other XR qualia such as presence or body ownership. The experiments introduce and utilize breaks in plausibility (in analogy to breaks in presence): We induce incoherence on the perceptual and the cognitive layer simultaneously by a simulation of object behaviors that do not conform to the laws of physics, i.e., gravity. We show that this manipulation breaks plausibility and hence confirm that it results in the desired effects in the theorized condition space but that the breaks in plausibility did not affect presence. In addition, we show that a cognitive manipulation by a storyline framing is too weak to successfully counteract the strong bottom-up inconsistencies. Both results are in line with the predictions of the recently introduced three-layer model of coherence and plausibility, which incorporates well-known top-down and bottom-up rivalries and its theorized increased independence between plausibility and presence.}, author = {Brübach, Larissa and Westermeier, Franziska and Wienrich, Carolin and Latoschik, Marc Erich}, journal = {IEEE Transactions on Visualization and Computer Graphics}, keywords = {myown}, note = {IEEE VR Best Journal Paper Nominee 🏆}, pages = {1-1}, title = {Breaking Plausibility Without Breaking Presence - Evidence For The Multi-Layer Nature Of Plausibility}, year = 2022 }
52.
Latoschik, M.E., Wienrich, C.: Congruence and Plausibility, not Presence?! Pivotal Conditions for XR Experiences and Effects, a Novel Model. Frontiers in Virtual Reality. 3, (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Presence is often considered the most important quale describing the subjective feeling of being in a computer-generated and/or computer-mediated virtual environment. The identification and separation of orthogonal presence components, i.e., the place illusion and the plausibility illusion, has been an accepted theoretical model describing Virtual Reality (VR) experiences for some time. This perspective article challenges this presence-oriented VR theory. First, we argue that a place illusion cannot be the major construct to describe the much wider scope of virtual, augmented, and mixed reality (VR, AR, MR: or XR for short). Second, we argue that there is no plausibility illusion but merely plausibility, and we derive the place illusion caused by the congruent and plausible generation of spatial cues and similarly for all the current model’s so-defined illusions. Finally, we propose congruence and plausibility to become the central essential conditions in a novel theoretical model describing XR experiences and effects.
@article{latoschik2021coherence, abstract = {Presence is often considered the most important quale describing the subjective feeling of being in a computer-generated and/or computer-mediated virtual environment. The identification and separation of orthogonal presence components, i.e., the place illusion and the plausibility illusion, has been an accepted theoretical model describing Virtual Reality (VR) experiences for some time. This perspective article challenges this presence-oriented VR theory. First, we argue that a place illusion cannot be the major construct to describe the much wider scope of virtual, augmented, and mixed reality (VR, AR, MR: or XR for short). Second, we argue that there is no plausibility illusion but merely plausibility, and we derive the place illusion caused by the congruent and plausible generation of spatial cues and similarly for all the current model’s so-defined illusions. Finally, we propose congruence and plausibility to become the central essential conditions in a novel theoretical model describing XR experiences and effects.}, author = {Latoschik, Marc Erich and Wienrich, Carolin}, journal = {Frontiers in Virtual Reality}, keywords = {myown}, month = {jun}, title = {Congruence and Plausibility, not Presence?! Pivotal Conditions for XR Experiences and Effects, a Novel Model}, volume = 3, year = 2022 }
53.
Birnstiel, S., Oberdörfer, S., Latoschik, M.E.: Stay Safe! Safety Precautions for Walking on a Conventional Treadmill in VR. Proceedings of the 29th IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VR ’22). 732–733 (2022).
[ BibTeX ] [ URL ] [ DOI ]
 
@article{birnstiel2022safety, author = {Birnstiel, Sandra and Oberdörfer, Sebastian and Latoschik, Marc Erich}, journal = {Proceedings of the 29th IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VR '22)}, keywords = {myown oberdoerfer}, pages = {732-733}, title = {Stay Safe! Safety Precautions for Walking on a Conventional Treadmill in VR}, year = 2022 }
54.
Mal, D., Wolf, E., Döllinger, N., Botsch, M., Wienrich, C., Latoschik, M.E.: Virtual Human Coherence and Plausibility – Towards a Validated Scale. Proceedings of the 29th IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VR ’22). S. 788–789 (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Virtual humans contribute to users’ state of plausibility in various XR applications. We present the development and preliminary evaluation of a self-assessment questionnaire to quantify virtual human’s plausibility in virtual environments based on eleven concise items. A principal component analysis of 650 appraisals collected in an online survey revealed two highly reliable components within the items. We interpret the components as possible factors, i.e., appearance and behavior plausibility and match to the virtual environment, and propose future work aiming towards a standardized virtual human plausibility scale by validating the structure and sensitivity of both sub-components in XR environments.
@inproceedings{mal2022virtual, abstract = {Virtual humans contribute to users’ state of plausibility in various XR applications. We present the development and preliminary evaluation of a self-assessment questionnaire to quantify virtual human’s plausibility in virtual environments based on eleven concise items. A principal component analysis of 650 appraisals collected in an online survey revealed two highly reliable components within the items. We interpret the components as possible factors, i.e., appearance and behavior plausibility and match to the virtual environment, and propose future work aiming towards a standardized virtual human plausibility scale by validating the structure and sensitivity of both sub-components in XR environments.}, author = {Mal, David and Wolf, Erik and Döllinger, Nina and Botsch, Mario and Wienrich, Carolin and Latoschik, Marc Erich}, booktitle = {Proceedings of the 29th IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VR '22)}, keywords = {dmal ewolf myown vitras}, pages = {788-789}, title = {Virtual Human Coherence and Plausibility – Towards a Validated Scale}, year = 2022 }
55.
Firman, O., Kindermann, P., Klawitter, J., Klemz, B., Klesen, F., Wolff, A.: Outside-Obstacle Representations with All Vertices on the Outer Face. In: Di Giacomo, E. und Montecchiani, F. (hrsg.) Proc. 38th Europ. Workshop Comput. Geom. (EuroCG’22). S. 54:1–8 (2022).
[ BibTeX ]
 
@inproceedings{fkkkkw-ooravof-EuroCG22, author = {Firman, Oksana and Kindermann, Philipp and Klawitter, Jonathan and Klemz, Boris and Klesen, Felix and Wolff, Alexander}, booktitle = {Proc. 38th Europ. Workshop Comput. Geom. (EuroCG'22)}, editor = {{Di Giacomo}, Emilio and Montecchiani, Fabrizio}, keywords = {myown}, pages = {54:1–8}, title = {Outside-Obstacle Representations with All Vertices on the Outer Face}, year = 2022 }
56.
Schmid, K., Knote, A., Mück, A., Pfeiffer, K., von Mammen, S., Fischer, S.C.: Interactive, Visual Simulation of a Spatio-Temporal Model of Gas Exchange in the Human Alveolus. Frontiers in Bioinformatics. 1, (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
In interdisciplinary fields such as systems biology, good communication between experimentalists and theorists is crucial for the success of a project. Theoretical modeling in physiology usually describes complex systems with many interdependencies. On one hand, these models have to be grounded on experimental data. On the other hand, experimenters must be able to understand the interdependent complexities of the theoretical model in order to interpret the model’s results in the physiological context. We promote interactive, visual simulations as an engaging way to present theoretical models in physiology and to make complex processes tangible. Based on a requirements analysis, we developed a new model for gas exchange in the human alveolus in combination with an interactive simulation software named Alvin. Alvin exceeds the current standard with its spatio-temporal resolution and a combination of visual and quantitative feedback. In Alvin, the course of the simulation can be traced in a three-dimensional rendering of an alveolus and dynamic plots. The user can interact by configuring essential model parameters. Alvin allows to run and compare multiple simulation instances simultaneously. We exemplified the use of Alvin for research by identifying unknown dependencies in published experimental data. Employing a detailed questionnaire, we showed the benefits of Alvin for education. We postulate that interactive, visual simulation of theoretical models, as we have implemented with Alvin on respiratory processes in the alveolus, can be of great help for communication between specialists and thereby advancing research.
@article{10.3389/fbinf.2021.774300, abstract = {In interdisciplinary fields such as systems biology, good communication between experimentalists and theorists is crucial for the success of a project. Theoretical modeling in physiology usually describes complex systems with many interdependencies. On one hand, these models have to be grounded on experimental data. On the other hand, experimenters must be able to understand the interdependent complexities of the theoretical model in order to interpret the model’s results in the physiological context. We promote interactive, visual simulations as an engaging way to present theoretical models in physiology and to make complex processes tangible. Based on a requirements analysis, we developed a new model for gas exchange in the human alveolus in combination with an interactive simulation software named Alvin. Alvin exceeds the current standard with its spatio-temporal resolution and a combination of visual and quantitative feedback. In Alvin, the course of the simulation can be traced in a three-dimensional rendering of an alveolus and dynamic plots. The user can interact by configuring essential model parameters. Alvin allows to run and compare multiple simulation instances simultaneously. We exemplified the use of Alvin for research by identifying unknown dependencies in published experimental data. Employing a detailed questionnaire, we showed the benefits of Alvin for education. We postulate that interactive, visual simulation of theoretical models, as we have implemented with Alvin on respiratory processes in the alveolus, can be of great help for communication between specialists and thereby advancing research.}, author = {Schmid, Kerstin and Knote, Andreas and Mück, Alexander and Pfeiffer, Keram and von Mammen, Sebastian and Fischer, Sabine C.}, journal = {Frontiers in Bioinformatics}, keywords = {myown}, title = {Interactive, Visual Simulation of a Spatio-Temporal Model of Gas Exchange in the Human Alveolus}, volume = 1, year = 2022 }
57.
Klawitter, J., Klesen, F., Wolff, A.: Algorithms for Floor Planning with Proximity Requirements. In: Gerber, D.J., Nahmad, A., Bogosian, B., Pantazis, E., und Miltiadis, C. (hrsg.) Proc. CAAD Future 2021. S. 151–171. Springer-Verlag (2022).
[ BibTeX ] [ DOI ]
 
@inproceedings{kkw-afppr-CAADF21, author = {Klawitter, Jonathan and Klesen, Felix and Wolff, Alexander}, booktitle = {Proc. CAAD Future 2021}, editor = {Gerber, David J. and Nahmad, Alicia and Bogosian, Biayna and Pantazis, Evan and Miltiadis, Constantinos}, keywords = {myown}, pages = {151–171}, publisher = {Springer-Verlag}, series = {CCIS}, title = {Algorithms for Floor Planning with Proximity Requirements}, volume = 1465, year = 2022 }
58.
Oberdörfer, S., Schraudt, D., Latoschik, M.E.: Embodied Gambling–Investigating the Influence of Level of Embodiment, Avatar Appearance, and Virtual Environment Design on an Online VR Slot Machine. Frontiers in Virtual Reality. 3, (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Slot machines are one of the most played games by players suffering from gambling disorder. New technologies like immersive Virtual Reality (VR) offer more possibilities to exploit erroneous beliefs in the context of gambling. Recent research indicates a higher risk potential when playing a slot machine in VR than on desktop. To continue this investigation, we evaluate the effects of providing different degrees of embodiment, i.e., minimal and full embodiment. The avatars used for the full embodiment further differ in their appearance, i.e., they elicit a high or a low socio-economic status. The virtual environment (VE) design can cause a potential influence on the overall gambling behavior. Thus, we also embed the slot machine in two different VEs that differ in their emotional design: a colorful underwater playground environment and a virtual counterpart of our lab. These design considerations resulted in four different versions of the same VR slot machine: 1) full embodiment with high socio-economic status, 2) full embodiment with low socio-economic status, 3) minimal embodiment playground VE, and 4) minimal embodiment laboratory VE. Both full embodiment versions also used the playground VE. We determine the risk potential by logging gambling frequency as well as stake size, and measuring harm-inducing factors, i.e., dissociation, urge to gamble, dark flow, and illusion of control, using questionnaires. Following a between groups experimental design, 82 participants played for 20 game rounds one of the four versions. We recruited our sample from the students enrolled at the University of Würzburg. Our safety protocol ensured that only participants without any recent gambling activity took part in the experiment. In this comparative user study, we found no effect of the embodiment nor VE design on neither the gambling frequency, stake sizes, nor risk potential. However, our results provide further support for the hypothesis of the higher visual angle on gambling stimuli and hence the increased emotional response being the true cause for the higher risk potential.
@article{oberdorfer2022embodied, abstract = {Slot machines are one of the most played games by players suffering from gambling disorder. New technologies like immersive Virtual Reality (VR) offer more possibilities to exploit erroneous beliefs in the context of gambling. Recent research indicates a higher risk potential when playing a slot machine in VR than on desktop. To continue this investigation, we evaluate the effects of providing different degrees of embodiment, i.e., minimal and full embodiment. The avatars used for the full embodiment further differ in their appearance, i.e., they elicit a high or a low socio-economic status. The virtual environment (VE) design can cause a potential influence on the overall gambling behavior. Thus, we also embed the slot machine in two different VEs that differ in their emotional design: a colorful underwater playground environment and a virtual counterpart of our lab. These design considerations resulted in four different versions of the same VR slot machine: 1) full embodiment with high socio-economic status, 2) full embodiment with low socio-economic status, 3) minimal embodiment playground VE, and 4) minimal embodiment laboratory VE. Both full embodiment versions also used the playground VE. We determine the risk potential by logging gambling frequency as well as stake size, and measuring harm-inducing factors, i.e., dissociation, urge to gamble, dark flow, and illusion of control, using questionnaires. Following a between groups experimental design, 82 participants played for 20 game rounds one of the four versions. We recruited our sample from the students enrolled at the University of Würzburg. Our safety protocol ensured that only participants without any recent gambling activity took part in the experiment. In this comparative user study, we found no effect of the embodiment nor VE design on neither the gambling frequency, stake sizes, nor risk potential. However, our results provide further support for the hypothesis of the higher visual angle on gambling stimuli and hence the increased emotional response being the true cause for the higher risk potential.}, author = {Oberdörfer, Sebastian and Schraudt, David and Latoschik, Marc Erich}, journal = {Frontiers in Virtual Reality}, keywords = {myown oberdoerfer}, title = {Embodied Gambling–Investigating the Influence of Level of Embodiment, Avatar Appearance, and Virtual Environment Design on an Online VR Slot Machine}, volume = 3, year = 2022 }
59.
Zink, J., Walter, J., Baumeister, J., Wolff, A.: Layered Drawing of Undirected Graphs with Generalized Port Constraints. Computational Geometry: Theory and Applications. (2022).
[ Abstract ] [ BibTeX ]
 
The aim of this research is a practical method to draw cable plans of complex machines. Such plans consist of electronic components and cables connecting specific ports of the components. Since the machines are configured for each client individually, cable plans need to be drawn automatically. The drawings must be well readable so that technicians can use them to debug the machines. In order to model plug sockets, we introduce port groups; within a group, ports can change their position (which we use to improve the aesthetics of the layout), but together the ports of a group must form a contiguous block. par We approach the problem of drawing such cable plans by extending the well-known Sugiyama framework such that it incorporates ports and port groups. Since the framework assumes directed graphs, we propose several ways to orient the edges of the given undirected graph. We compare these methods experimentally, both on real-world data and synthetic data that carefully simulates real-world data. We measure the aesthetics of the resulting drawings by counting bends and crossings. Using these metrics, we experimentally compare our approach to Kieler [JVLC 2014], a library for drawing graphs in the presence of port constraints. Our method produced 10--30 % fewer crossings, while it performed equally well or slightly worse than Kieler with respect to the number of bends and the time used to compute a drawing.
@article{zwbw-ldugg-CGTA22, abstract = {The aim of this research is a practical method to draw cable plans of complex machines. Such plans consist of electronic components and cables connecting specific ports of the components. Since the machines are configured for each client individually, cable plans need to be drawn automatically. The drawings must be well readable so that technicians can use them to debug the machines. In order to model plug sockets, we introduce port groups; within a group, ports can change their position (which we use to improve the aesthetics of the layout), but together the ports of a group must form a contiguous block. \par We approach the problem of drawing such cable plans by extending the well-known Sugiyama framework such that it incorporates ports and port groups. Since the framework assumes directed graphs, we propose several ways to orient the edges of the given undirected graph. We compare these methods experimentally, both on real-world data and synthetic data that carefully simulates real-world data. We measure the aesthetics of the resulting drawings by counting bends and crossings. Using these metrics, we experimentally compare our approach to Kieler [JVLC 2014], a library for drawing graphs in the presence of port constraints. Our method produced 10–30 \% fewer crossings, while it performed equally well or slightly worse than Kieler with respect to the number of bends and the time used to compute a drawing.}, author = {Zink, Johannes and Walter, Julian and Baumeister, Joachim and Wolff, Alexander}, journal = {Computational Geometry: Theory and Applications}, keywords = {Sugiyama_framework experimental_evaluation layered_drawings myown port_constraints}, note = {To appear}, title = {Layered Drawing of Undirected Graphs with Generalized Port Constraints}, year = 2022 }
60.
Wolf, E., Fiedler, M.L., Döllinger, N., Wienrich, C., Latoschik, M.E.: Exploring Presence, Avatar Embodiment, and Body Perception with a Holographic Augmented Reality Mirror. 2022 IEEE Conference on Virtual Reality and 3D User Interfaces (VR). S. 350–359 (2022).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
The embodiment of avatars in virtual reality (VR) is a promising tool for enhancing the user's mental health. A great example is the treatment of body image disturbances, where eliciting a full-body illusion can help identify, visualize, and modulate persisting misperceptions. Augmented reality (AR) could complement recent advances in the field by incorporating real elements, such as the therapist or the user's real body, into therapeutic scenarios. However, research on the use of AR in this context is very sparse. Therefore, we present a holographic AR mirror system based on an optical see-through (OST) device and markerless body tracking, collect valuable qualitative feedback regarding its user experience, and compare quantitative results regarding presence, embodiment, and body weight perception to similar systems using video see-through (VST) AR and VR. For our OST AR system, a total of 27 normal-weight female participants provided predominantly positive feedback on display properties (field of view, luminosity, and transparency of virtual objects), body tracking, and the perception of the avatar’s appearance and movements. In the quantitative comparison to the VST AR and VR systems, participants reported significantly lower feelings of presence, while they estimated the body weight of the generic avatar significantly higher when using our OST AR system. For virtual body ownership and agency, we found only partially significant differences. In summary, our study shows the general applicability of OST AR in the given context offering huge potential in future therapeutic scenarios. However, the comparative evaluation between OST AR, VST AR, and VR also revealed significant differences in relevant measures. Future work is mandatory to corroborate our findings and to classify the significance in a therapeutic context.
@inproceedings{wolf2022holographic, abstract = {The embodiment of avatars in virtual reality (VR) is a promising tool for enhancing the user's mental health. A great example is the treatment of body image disturbances, where eliciting a full-body illusion can help identify, visualize, and modulate persisting misperceptions. Augmented reality (AR) could complement recent advances in the field by incorporating real elements, such as the therapist or the user's real body, into therapeutic scenarios. However, research on the use of AR in this context is very sparse. Therefore, we present a holographic AR mirror system based on an optical see-through (OST) device and markerless body tracking, collect valuable qualitative feedback regarding its user experience, and compare quantitative results regarding presence, embodiment, and body weight perception to similar systems using video see-through (VST) AR and VR. For our OST AR system, a total of 27 normal-weight female participants provided predominantly positive feedback on display properties (field of view, luminosity, and transparency of virtual objects), body tracking, and the perception of the avatar’s appearance and movements. In the quantitative comparison to the VST AR and VR systems, participants reported significantly lower feelings of presence, while they estimated the body weight of the generic avatar significantly higher when using our OST AR system. For virtual body ownership and agency, we found only partially significant differences. In summary, our study shows the general applicability of OST AR in the given context offering huge potential in future therapeutic scenarios. However, the comparative evaluation between OST AR, VST AR, and VR also revealed significant differences in relevant measures. Future work is mandatory to corroborate our findings and to classify the significance in a therapeutic context.}, author = {Wolf, Erik and Fiedler, Marie Luisa and Döllinger, Nina and Wienrich, Carolin and Latoschik, Marc Erich}, booktitle = {2022 IEEE Conference on Virtual Reality and 3D User Interfaces (VR)}, keywords = {ewolf myown vitras}, pages = {350-359}, title = {Exploring Presence, Avatar Embodiment, and Body Perception with a Holographic Augmented Reality Mirror}, year = 2022 }
61.
Dietz, K., Gray, N., Seufert, M., Hoßfeld, T.: ML-based Performance Prediction of SDN using Simulated Data from Real and Synthetic Networks. 33th IEEE/IFIP Network Operations and Management Symposium (NOMS). , Budapest, Hungary (2022).
[ BibTeX ]
 
@inproceedings{info3-inproceedings-2022-2, address = {Budapest, Hungary}, author = {Dietz, Katharina and Gray, Nicholas and Seufert, Michael and Hoßfeld, Tobias}, booktitle = {33th IEEE/IFIP Network Operations and Management Symposium (NOMS)}, keywords = {myown wintermute ucn}, month = 4, title = {ML-based Performance Prediction of SDN using Simulated Data from Real and Synthetic Networks}, year = 2022 }
62.
Goeßmann, I., Klawitter, J., Klemz, B., Klesen, F., Kobourov, S.G., Kryven, M., Wolff, A., Zink, J.: The Segment Number: Algorithms and Universal Lower Bounds for Some Classes of Planar Graphs. In: Bekos, M. und Kaufmann, M. (hrsg.) Proc. 48th Int. Workshop Graph-Theoretic Concepts Comput. Sci. (WG’22). Springer-Verlag (2022).
[ BibTeX ]
 
@inproceedings{gkkkkkwz-snaul-WG22, author = {Goeßmann, Ina and Klawitter, Jonathan and Klemz, Boris and Klesen, Felix and Kobourov, Stephen G. and Kryven, Myroslav and Wolff, Alexander and Zink, Johannes}, booktitle = {Proc. 48th Int. Workshop Graph-Theoretic Concepts Comput. Sci. (WG'22)}, editor = {Bekos, Michael and Kaufmann, Michael}, keywords = {arc_number convex_drawings graph_drawing myown segment_number universal_lower_bounds visual_complexity}, note = {To appear}, publisher = {Springer-Verlag}, series = {Lecture Notes in Computer Science}, title = {The Segment Number: Algorithms and Universal Lower Bounds for Some Classes of Planar Graphs}, year = 2022 }
63.
Wehner, N., Ring, M., Schüler, J., Hotho, A., Hoßfeld, T., Seufert, M.: On Learning Hierarchical Embeddings from Encrypted Network Traffic. 33th IEEE/IFIP Network Operations and Management Symposium (NOMS). , Budapest, Hungary (2022).
[ Abstract ] [ BibTeX ]
 
This work presents a novel concept for learning embeddings from encrypted network traffic. In contrast to existing approaches, we evaluate the feasibility of hierarchical embeddings by iteratively aggregating packet embeddings to flow embeddings, and flow embeddings to trace embeddings. The hierarchical embedding concept was designed to especially consider complex dependencies of Internet traffic on different time scales. We describe this novel embedding concept for the domain of network traffic in full detail, and evaluate its performance for the downstream task of website fingerprinting, i.e., identifying websites from encrypted traffic, which is relevant for network management, e.g., as a prerequisite for QoE monitoring or for intrusion detection. Our evaluation reveals that embeddings are a promising solution for website fingerprinting as our model correctly labels up to 99.8% of traces from 500 target websites.
@inproceedings{info3-inproceedings-2022-1, abstract = {This work presents a novel concept for learning embeddings from encrypted network traffic. In contrast to existing approaches, we evaluate the feasibility of hierarchical embeddings by iteratively aggregating packet embeddings to flow embeddings, and flow embeddings to trace embeddings. The hierarchical embedding concept was designed to especially consider complex dependencies of Internet traffic on different time scales. We describe this novel embedding concept for the domain of network traffic in full detail, and evaluate its performance for the downstream task of website fingerprinting, i.e., identifying websites from encrypted traffic, which is relevant for network management, e.g., as a prerequisite for QoE monitoring or for intrusion detection. Our evaluation reveals that embeddings are a promising solution for website fingerprinting as our model correctly labels up to 99.8\% of traces from 500 target websites.}, address = {Budapest, Hungary}, author = {Wehner, Nikolas and Ring, Markus and Schüler, Joshua and Hotho, Andreas and Hoßfeld, Tobias and Seufert, Michael}, booktitle = {33th IEEE/IFIP Network Operations and Management Symposium (NOMS)}, keywords = {myown}, month = 4, title = {On Learning Hierarchical Embeddings from Encrypted Network Traffic}, year = 2022 }
64.
Klawitter, J., Klemz, B., Klesen, F., Kobourov, S., Kryven, M., Wolff, A., Zink, J.: Universal Lower Bounds on the Segment Number of Some Classes of Planar Graphs. In: Di Giacomo, E. und Montecchiani, F. (hrsg.) Proc. 38th Europ. Workshop Comput. Geom. (EuroCG’22). S. 53:1–7 (2022).
[ BibTeX ]
 
@inproceedings{kkkkkwz-ulbsn-EuroCG22, author = {Klawitter, Jonathan and Klemz, Boris and Klesen, Felix and Kobourov, Stephen and Kryven, Myroslav and Wolff, Alexander and Zink, Johannes}, booktitle = {Proc. 38th Europ. Workshop Comput. Geom. (EuroCG'22)}, editor = {{Di Giacomo}, Emilio and Montecchiani, Fabrizio}, keywords = {myown}, pages = {53:1–7}, title = {Universal Lower Bounds on the Segment Number of Some Classes of Planar Graphs}, year = 2022 }
65.
Ganal, E., Heimbrock, M., Schaper, P., Lugrin, B.: Don’t Touch This! - Investigating the Potential of Visualizing Touched Surfaces on the Consideration of Behavior Change. In: Baghaei, N., Vassileva, J., Ali, R., und Oyibo, K. (hrsg.) Persuasive Technology 2022. Springer International Publishing (2022).
[ BibTeX ]
 
@inproceedings{ganal2022touch, author = {Ganal, E. and Heimbrock, M. and Schaper, P. and Lugrin, B.}, booktitle = {Persuasive Technology 2022}, editor = {Baghaei, N. and Vassileva, J. and Ali, R. and Oyibo, K.}, keywords = {birgit ganal mi myown reflectedreality schaper}, publisher = {Springer International Publishing}, title = {Don’t Touch This! - Investigating the Potential of Visualizing Touched Surfaces on the Consideration of Behavior Change}, year = 2022 }

2021 [ nach oben ]

1.
Schreiner, L., von Mammen, S.: Modding Support of Game Engines. The 16th International Conference on the Foundations of Digital Games (FDG) 2021. Association for Computing Machinery, Montreal, QC, Canada (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
This paper aims at showing how different game engines support modding. To this end, the concepts of modding and game engines alongside their historical evolution are introduced first. Additionally, some well-known game engines and mods are presented, and their unique features are described. Further, the effects of using game engines and those that modding has on games, developers, and players are laid out. Particular focus is placed on the effects on competitive games. These effects include an enhanced lifespan for games and the requirement for more development effort. Finally, the modding-support of selected game engines is illustrated and compared with each other. These engines are the id Tech engine(s), Unreal Engine, the Source engine, and Unity. The paper is then concluded with an outlook on future research possibilities and recommendations to developers.
@inproceedings{10.1145/3472538.3472574, abstract = {This paper aims at showing how different game engines support modding. To this end, the concepts of modding and game engines alongside their historical evolution are introduced first. Additionally, some well-known game engines and mods are presented, and their unique features are described. Further, the effects of using game engines and those that modding has on games, developers, and players are laid out. Particular focus is placed on the effects on competitive games. These effects include an enhanced lifespan for games and the requirement for more development effort. Finally, the modding-support of selected game engines is illustrated and compared with each other. These engines are the id Tech engine(s), Unreal Engine, the Source engine, and Unity. The paper is then concluded with an outlook on future research possibilities and recommendations to developers.}, address = {New York, NY, USA}, author = {Schreiner, Lukas and von Mammen, Sebastian}, booktitle = {The 16th International Conference on the Foundations of Digital Games (FDG) 2021}, keywords = {myown}, publisher = {Association for Computing Machinery}, series = {FDG'21}, title = {Modding Support of Game Engines}, year = 2021 }
2.
Dietz, K., Mühlhauser, M., Seufert, M., Gray, N., Hoßfeld, T., Herrmann, D.: Browser Fingerprinting: How to Protect Machine Learning Models and Data with Differential Privacy?. 1st International Workshop on Machine Learning in Networking (MaLeNe). , Lübeck, Germany (Virtual Conference) (2021).
[ BibTeX ]
 
@inproceedings{info3-inproceedings-2021-16, address = {Lübeck, Germany (Virtual Conference)}, author = {Dietz, Katharina and Mühlhauser, Michael and Seufert, Michael and Gray, Nicholas and Hoßfeld, Tobias and Herrmann, Dominik}, booktitle = {1st International Workshop on Machine Learning in Networking (MaLeNe)}, keywords = {myown wintermute ucn}, month = 9, title = {Browser Fingerprinting: How to Protect Machine Learning Models and Data with Differential Privacy?}, year = 2021 }
3.
Tran, H.T., Pham Ngoc, N., Hoßfeld, T., Seufert, M., Thang, T.C.: Cumulative Quality Modeling for HTTP Adaptive Streaming. ACM Transactions on Multimedia Computing, Communications, and Applications. 17, 22 (1–24) (2021).
[ BibTeX ]
 
@article{info3-article-2021-1, author = {Tran, Huyen TT and Pham Ngoc, Nam and Hoßfeld, Tobias and Seufert, Michael and Thang, Truong Cong}, journal = {ACM Transactions on Multimedia Computing, Communications, and Applications}, keywords = {myown ucn}, month = 4, number = 1, pages = {22 (1-24)}, title = {Cumulative Quality Modeling for HTTP Adaptive Streaming}, volume = 17, year = 2021 }
4.
Loh, F., Raffeck, S., Metzger, F., Hoßfeld, T.: Improving LoRaWAN’s Successful Information Transmission Rate with Redundancy. 17th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob) (2021).
[ Abstract ] [ BibTeX ]
 
The adaptation of Internet of Things in our everyday life shows different new demands and challenges. One of the fastest growing technologies in this context are Low Power Wide Area Networks with LoRaWAN as one of their most prominent representatives. The promise of this technology is to transmit sensor data over large distances with very little energy consumption. But transmission behavior, and especially overhead and collision probability, must be studied in detail to improve transmission quality and energy consumption due to the random access nature of LoRaWAN. Because of that, this work investigates the LoRaWAN channel capacity by analyzing the transmission overhead, the collision probability, and the data loss. At the end, an energy consumption comparison is done. The contribution is a novel approach based on aggregation and retransmission that shows a decreased data loss of up to 20% compared to the currently used random channel access.
@inproceedings{info3-inproceedings-2021-19, abstract = {The adaptation of Internet of Things in our everyday life shows different new demands and challenges. One of the fastest growing technologies in this context are Low Power Wide Area Networks with LoRaWAN as one of their most prominent representatives. The promise of this technology is to transmit sensor data over large distances with very little energy consumption. But transmission behavior, and especially overhead and collision probability, must be studied in detail to improve transmission quality and energy consumption due to the random access nature of LoRaWAN. Because of that, this work investigates the LoRaWAN channel capacity by analyzing the transmission overhead, the collision probability, and the data loss. At the end, an energy consumption comparison is done. The contribution is a novel approach based on aggregation and retransmission that shows a decreased data loss of up to 20% compared to the currently used random channel access.}, author = {Loh, Frank and Raffeck, Simon and Metzger, Florian and Hoßfeld, Tobias}, booktitle = {17th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)}, keywords = {myown 5mart}, month = 10, title = {Improving LoRaWAN’s Successful Information Transmission Rate with Redundancy}, year = 2021 }
5.
Bosch, Y., Schäfer, P., Spoerhase, J., Storandt, S., Zink, J.: Consistent Simplification of Polyline Tree Bundles. Proc. 27th International Computing and Combinatorics Conference (COCOON’21) (2021).
[ BibTeX ]
 
@inproceedings{bosch-etal21:polyline-simplification, author = {Bosch, Yannick and Schäfer, Peter and Spoerhase, Joachim and Storandt, Sabine and Zink, Johannes}, booktitle = {Proc. 27th International Computing and Combinatorics Conference (COCOON'21)}, keywords = {approximability graph myown network polyline simplification tree}, note = {to appear}, title = {Consistent Simplification of Polyline Tree Bundles}, year = 2021 }
6.
Ripka, G., Grafe, S., Latoschik, M.E.: Peer group supervision in Zoom and social VR-Preparing preservice teachers for planning and designing digital media integrated classes. EdMedia+ Innovate Learning. S. 602–616. Association for the Advancement of Computing in Education (AACE) (2021).
[ Abstract ] [ BibTeX ]
 
21-century challenges demand a change towards collaborative and constructive seminar designs in initial teacher education regarding preservice teachers acquiring meta-conceptual awareness (TPACK) about how to implement emerging technologies in their future profession. Against this background the paper addresses the following research questions: 1) How should a pedagogical concept for remote initial teacher education be designed to promote metacognitive learning processes of preservice teachers? 2) How do preservice teachers perceive these learning processes in video-based communication and social VR? Regarding the pedagogical concept, peer group supervision and an action-and development-oriented approach using Zoom and social VR were identified as relevant for an instructional design that provides collaborative and constructive learning processes for students. In this exploratory study, 17 students participated in two iterative cycles of peer group supervision performing design tasks in groups. A content analysis of reflective video statements and qualitative group interviews was carried out using a qualitative research design. Results indicate the successful implementation of peer group supervision. Regarding media's implementation, Zoom's screen-sharing option and breakout session benefitted the consultation process as well as social VR's "realistic" experience of creating a "sense of community".
@inproceedings{ripka2021peer, abstract = {21-century challenges demand a change towards collaborative and constructive seminar designs in initial teacher education regarding preservice teachers acquiring meta-conceptual awareness (TPACK) about how to implement emerging technologies in their future profession. Against this background the paper addresses the following research questions: 1) How should a pedagogical concept for remote initial teacher education be designed to promote metacognitive learning processes of preservice teachers? 2) How do preservice teachers perceive these learning processes in video-based communication and social VR? Regarding the pedagogical concept, peer group supervision and an action-and development-oriented approach using Zoom and social VR were identified as relevant for an instructional design that provides collaborative and constructive learning processes for students. In this exploratory study, 17 students participated in two iterative cycles of peer group supervision performing design tasks in groups. A content analysis of reflective video statements and qualitative group interviews was carried out using a qualitative research design. Results indicate the successful implementation of peer group supervision. Regarding media's implementation, Zoom's screen-sharing option and breakout session benefitted the consultation process as well as social VR's "realistic" experience of creating a "sense of community".}, author = {Ripka, Gabriela and Grafe, Silke and Latoschik, Marc Erich}, booktitle = {EdMedia+ Innovate Learning}, keywords = {myown}, organization = {Association for the Advancement of Computing in Education (AACE)}, pages = {602-616}, title = {Peer group supervision in Zoom and social VR-Preparing preservice teachers for planning and designing digital media integrated classes}, year = 2021 }
7.
Korger, A., Baumeister, J.: Rule-based Semantic Relation Extraction in Regulatory Documents. Learning. Knowledge. Data. Analytics. , Munich, Germany (2021).
[ BibTeX ]
 
@inproceedings{Korger2021, address = {Munich, Germany}, author = {Korger, Andreas and Baumeister, Joachim}, booktitle = {Learning. Knowledge. Data. Analytics}, keywords = {myown rokt}, month = {September}, title = {Rule-based Semantic Relation Extraction in Regulatory Documents}, year = 2021 }
8.
Hirth, M., Seufert, M., Lange, S., Meixner, M., Tran-Gia, P.: Performance Evaluation of Hybrid Crowdsensing and Fixed Sensor Systems for Event Detection in Urban Environments. Sensors. 21, 5880 (1–19) (2021).
[ Abstract ] [ BibTeX ]
 
Crowdsensing offers a cost-effective way to collect large amounts of environmental sensor data. However, the spatial distribution of crowdsensing sensors can hardly be influenced, as the participants carry the sensors, and, additionally, the quality of the crowdsensed data can vary significantly. Hybrid systems that use mobile users in conjunction with fixed sensors might help to overcome these limitations, as such system allow assessing the quality of the submitted crowdsensed data and provide sensor values where no crowdsensing data is available. In this work, we use a simulation study to first analyze a simple crowdsensing system concerning the detection performance of spatial events to highlight the potential and limitations of a pure crowdsourcing system. The results indicate that even if only a small share of inhabitants participates in crowdsensing, events that have locations correlated with the population density can be easily and quickly detected using such a system. On the contrary, events with uniformly randomly distributed locations are much harder to detect using a simple crowdsensing-based approach. A second evaluation shows that hybrid systems improve the detection probability and time. Finally, we illustrate how to compute the minimum number of fixed sensors for given detection time thresholds in our exemplary scenario.
@article{info3-article-2021-4, abstract = {Crowdsensing offers a cost-effective way to collect large amounts of environmental sensor data. However, the spatial distribution of crowdsensing sensors can hardly be influenced, as the participants carry the sensors, and, additionally, the quality of the crowdsensed data can vary significantly. Hybrid systems that use mobile users in conjunction with fixed sensors might help to overcome these limitations, as such system allow assessing the quality of the submitted crowdsensed data and provide sensor values where no crowdsensing data is available. In this work, we use a simulation study to first analyze a simple crowdsensing system concerning the detection performance of spatial events to highlight the potential and limitations of a pure crowdsourcing system. The results indicate that even if only a small share of inhabitants participates in crowdsensing, events that have locations correlated with the population density can be easily and quickly detected using such a system. On the contrary, events with uniformly randomly distributed locations are much harder to detect using a simple crowdsensing-based approach. A second evaluation shows that hybrid systems improve the detection probability and time. Finally, we illustrate how to compute the minimum number of fixed sensors for given detection time thresholds in our exemplary scenario.}, author = {Hirth, Matthias and Seufert, Michael and Lange, Stanislav and Meixner, Markus and Tran-Gia, Phuoc}, journal = {Sensors}, keywords = {myown gbc ucn}, month = 8, number = 17, pages = {5880 (1-19)}, title = {Performance Evaluation of Hybrid Crowdsensing and Fixed Sensor Systems for Event Detection in Urban Environments}, volume = 21, year = 2021 }
9.
Bartl, A., Wenninger, S., Wolf, E., Botsch, M., Latoschik, M.E.: Affordable but not Cheap: A Case Study of the Effects of Two 3D-Reconstruction Methods of Virtual Humans. Frontiers in Virtual Reality. 2, (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Realistic and lifelike 3D-reconstruction of virtual humans has various exciting and important use cases. Our and others' appearances have notable effects on ourselves and our interaction partners in virtual environments, e.g., on acceptance, preference, trust, believability, behavior (the Proteus effect), and more. Today, multiple approaches for the 3D-reconstruction of virtual humans exist. They significantly vary in terms of the degree of achievable realism, the technical complexities, and finally, the overall reconstruction costs involved. This article compares two 3D-reconstruction approaches with very different hardware requirements. The high-cost solution uses a typical complex and elaborated camera rig consisting of 94 digital single-lens reflex (DSLR) cameras. The recently developed low-cost solution uses a smartphone camera to create videos that capture multiple views of a person. Both methods use photogrammetric reconstruction and template fitting with the same template model and differ in their adaptation to the method-specific input material. Each method generates high-quality virtual humans ready to be processed, animated, and rendered by standard XR simulation and game engines such as Unreal or Unity. We compare the results of the two 3D-reconstruction methods in an immersive virtual environment against each other in a user study. Our results indicate that the virtual humans from the low-cost approach are perceived similarly to those from the high-cost approach regarding the perceived similarity to the original, human-likeness, beauty, and uncanniness, despite significant differences in the objectively measured quality. The perceived feeling of change of the own body was higher for the low-cost virtual humans. Quality differences were perceived more strongly for one's own body than for other virtual humans.
@article{2021:bartl:affordable, abstract = {Realistic and lifelike 3D-reconstruction of virtual humans has various exciting and important use cases. Our and others' appearances have notable effects on ourselves and our interaction partners in virtual environments, e.g., on acceptance, preference, trust, believability, behavior (the Proteus effect), and more. Today, multiple approaches for the 3D-reconstruction of virtual humans exist. They significantly vary in terms of the degree of achievable realism, the technical complexities, and finally, the overall reconstruction costs involved. This article compares two 3D-reconstruction approaches with very different hardware requirements. The high-cost solution uses a typical complex and elaborated camera rig consisting of 94 digital single-lens reflex (DSLR) cameras. The recently developed low-cost solution uses a smartphone camera to create videos that capture multiple views of a person. Both methods use photogrammetric reconstruction and template fitting with the same template model and differ in their adaptation to the method-specific input material. Each method generates high-quality virtual humans ready to be processed, animated, and rendered by standard XR simulation and game engines such as Unreal or Unity. We compare the results of the two 3D-reconstruction methods in an immersive virtual environment against each other in a user study. Our results indicate that the virtual humans from the low-cost approach are perceived similarly to those from the high-cost approach regarding the perceived similarity to the original, human-likeness, beauty, and uncanniness, despite significant differences in the objectively measured quality. The perceived feeling of change of the own body was higher for the low-cost virtual humans. Quality differences were perceived more strongly for one's own body than for other virtual humans.}, author = {Bartl, Andrea and Wenninger, Stephan and Wolf, Erik and Botsch, Mario and Latoschik, Marc Erich}, journal = {Frontiers in Virtual Reality}, keywords = {ewolf hci-uwb myown via-vr vitras}, title = {Affordable but not Cheap: A Case Study of the Effects of Two 3D-Reconstruction Methods of Virtual Humans}, volume = 2, year = 2021 }
10.
Loh, F., Geissler, S., Schaible, F., Hoßfeld, T.: Talk to Me: Investigating the Traffic Characteristics of Amazon Echo Dot and Google Home. International Conference on Communications and Electronics, ICCE (2021).
[ Abstract ] [ BibTeX ]
 
The application area of smart speakers is steadily increasing with the Amazon Echo family and Google Home being brand leaders. Use cases include, among others, updating the calendar, home automation, or simply assisting users in their every day life. With the increasing amount of devices, the traffic generation and requesting process becomes a relevant subject to be studied in order to create traffic models and predict the impact on networks by these types of devices. Furthermore, with a detailed understanding of the devices, service quality can be monitored and improved for the end user. For that reason, in this work the requesting and traffic generation process of the Amazon Echo Dot and Google Home are studied and the generated network load of both devices is compared. With the insights of this study and additional device usage statistics, detailed traffic and usage models can be created.
@inproceedings{info3-inproceedings-2021-5, abstract = {The application area of smart speakers is steadily increasing with the Amazon Echo family and Google Home being brand leaders. Use cases include, among others, updating the calendar, home automation, or simply assisting users in their every day life. With the increasing amount of devices, the traffic generation and requesting process becomes a relevant subject to be studied in order to create traffic models and predict the impact on networks by these types of devices. Furthermore, with a detailed understanding of the devices, service quality can be monitored and improved for the end user. For that reason, in this work the requesting and traffic generation process of the Amazon Echo Dot and Google Home are studied and the generated network load of both devices is compared. With the insights of this study and additional device usage statistics, detailed traffic and usage models can be created.}, author = {Loh, Frank and Geissler, Stefan and Schaible, Fabian and Hoßfeld, Tobias}, booktitle = {International Conference on Communications and Electronics, ICCE}, keywords = {myown}, month = 1, title = {Talk to Me: Investigating the Traffic Characteristics of Amazon Echo Dot and Google Home}, year = 2021 }
11.
Casas, P., Wassermann, S., Wehner, N., Seufert, M., Schüler, J., Hoßfeld, T.: Mobile Web and App QoE Monitoring for ISPs - from Encrypted Traffic to Speed Index through Machine Learning. 13th Wireless and Mobile Networking Conference (WMNC), Best Paper Award. , Montreal, Canada (Virtual Conference) (2021).
[ BibTeX ]
 
@inproceedings{info3-inproceedings-2021-17, address = {Montreal, Canada (Virtual Conference)}, author = {Casas, Pedro and Wassermann, Sarah and Wehner, Nikolas and Seufert, Michael and Schüler, Joshua and Hoßfeld, Tobias}, booktitle = {13th Wireless and Mobile Networking Conference (WMNC), Best Paper Award}, keywords = {myown ucn}, month = 10, title = {Mobile Web and App QoE Monitoring for ISPs - from Encrypted Traffic to Speed Index through Machine Learning}, year = 2021 }
12.
Pimpinella, A., Redondi, A.E., Loh, F., Seufert, M.: Machine-Learning Based Prediction of Next HTTP Request Arrival Time in Adaptive Video Streaming. 3rd International Workshop on High-Precision, Predictable, and Low-Latency Networking (HiPNet). , Izmir, Turkey (Virtual Conference) (2021).
[ BibTeX ]
 
@inproceedings{info3-inproceedings-2021-18, address = {Izmir, Turkey (Virtual Conference)}, author = {Pimpinella, Andrea and Redondi, Alessandro E.C. and Loh, Frank and Seufert, Michael}, booktitle = {3rd International Workshop on High-Precision, Predictable, and Low-Latency Networking (HiPNet)}, keywords = {myown ucn}, month = 10, title = {Machine-Learning Based Prediction of Next HTTP Request Arrival Time in Adaptive Video Streaming}, year = 2021 }
13.
Glémarec, Y., Lugrin, J.- luc, Bosser, A.-G., Buche, C., Latoschik, M.E.: Conference Talk Training With a Virtual Audience System. ACM Symposium on Virtual Reality Software and Technology. (2021).
[ Abstract ] [ BibTeX ]
 
This paper presents the first prototype of a virtual audience sys-tem (VAS) specifically designed as a training tool for conferencetalks. This system has been tailored for university seminars dedi-cated to the preparation and delivery of scientific talks. We describethe required features which have been identified during the de-velopment process. We also summarize the preliminary feedbackreceived from lecturers and students during the first deployment ofthe system in seminars for bachelor and doctoral students. Finally,we discuss future work and research directions. We believe oursystem architecture and features are providing interesting insightson the development and integration of VR-based educational toolsinto university curriculum.
@article{noauthororeditor, abstract = {This paper presents the first prototype of a virtual audience sys-tem (VAS) specifically designed as a training tool for conferencetalks. This system has been tailored for university seminars dedi-cated to the preparation and delivery of scientific talks. We describethe required features which have been identified during the de-velopment process. We also summarize the preliminary feedbackreceived from lecturers and students during the first deployment ofthe system in seminars for bachelor and doctoral students. Finally,we discuss future work and research directions. We believe oursystem architecture and features are providing interesting insightson the development and integration of VR-based educational toolsinto university curriculum.}, author = {Glémarec, Yann and Lugrin, Jean-luc and Bosser, Anne-Gwenn and Buche, Cédric and Latoschik, Marc Erich}, journal = {ACM Symposium on Virtual Reality Software and Technology}, keywords = {lugrin myown vraudi}, title = {Conference Talk Training With a Virtual Audience System}, year = 2021 }
14.
Oberdörfer, S., Heidrich, D., Birnstiel, S., Latoschik, M.E.: Enchanted by Your Surrounding? Measuring the Effects of Immersion and Design of Virtual Environments on Decision-Making. Frontiers in Virtual Reality. 2, 101 (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@article{oberdorfer2021enchanted, author = {Oberdörfer, Sebastian and Heidrich, David and Birnstiel, Sandra and Latoschik, Marc Erich}, journal = {Frontiers in Virtual Reality}, keywords = {dark-sides-vr myown oberdoerfer}, pages = 101, title = {Enchanted by Your Surrounding? Measuring the Effects of Immersion and Design of Virtual Environments on Decision-Making}, volume = 2, year = 2021 }
15.
Wamser, F., Seufert, A., Hall, A., Wunderer, S., Hoßfeld, T.: Valid Statements by the Crowd: Statistical Measures for Precision in Crowdsourced Mobile Measurements. Network. 1, 215–232 (2021).
[ Abstract ] [ BibTeX ]
 
Crowdsourced network measurements (CNMs) are becoming increasingly popular as they assess the performance of a mobile network from the end user’s perspective on a large scale. Here, network measurements are performed directly on the end-users’ devices, thus taking advantage of the real-world conditions end-users encounter. However, this type of uncontrolled measurement raises questions about its validity and reliability. The problem lies in the nature of this type of data collection. In CNMs, mobile network subscribers are involved to a large extent in the measurement process, and collect data themselves for the operator. The collection of data on user devices in arbitrary locations and at uncontrolled times requires means to ensure validity and reliability. To address this issue, our paper defines concepts and guidelines for analyzing the precision of CNMs; specifically, the number of measurements required to make valid statements. In addition to the formal definition of the aspect, we illustrate the problem and use an extensive sample data set to show possible assessment approaches. This data set consists of more than 20.4 million crowdsourced mobile measurements from across France, measured by a commercial data provider.
@article{info3-article-2021-5, abstract = {Crowdsourced network measurements (CNMs) are becoming increasingly popular as they assess the performance of a mobile network from the end user’s perspective on a large scale. Here, network measurements are performed directly on the end-users’ devices, thus taking advantage of the real-world conditions end-users encounter. However, this type of uncontrolled measurement raises questions about its validity and reliability. The problem lies in the nature of this type of data collection. In CNMs, mobile network subscribers are involved to a large extent in the measurement process, and collect data themselves for the operator. The collection of data on user devices in arbitrary locations and at uncontrolled times requires means to ensure validity and reliability. To address this issue, our paper defines concepts and guidelines for analyzing the precision of CNMs; specifically, the number of measurements required to make valid statements. In addition to the formal definition of the aspect, we illustrate the problem and use an extensive sample data set to show possible assessment approaches. This data set consists of more than 20.4 million crowdsourced mobile measurements from across France, measured by a commercial data provider.}, author = {Wamser, Florian and Seufert, Anika and Hall, Andrew and Wunderer, Stefan and Hoßfeld, Tobias}, journal = {Network}, keywords = {myown can}, month = 9, number = 2, pages = {215–232}, title = {Valid Statements by the Crowd: Statistical Measures for Precision in Crowdsourced Mobile Measurements}, volume = 1, year = 2021 }
16.
Seufert, A., Schröder, S., Seufert, M.: Delivering User Experience over Networks: Towards a Quality of Experience Centered Design Cycle for Improved Design of Networked Applications. SN Computer Science. 2, (2021).
[ Abstract ] [ BibTeX ]
 
To deliver the best user experience (UX), the human-centered design cycle (HCDC) serves as a well-established guideline to application developers. However, it does not yet cover network-specific requirements, which become increasingly crucial, as most applications deliver experience over the Internet. The missing network-centric view is provided by Quality of Experience (QoE), which could team up with UX towards an improved overall experience. By considering QoE aspects during the development process, it can be achieved that applications become network-aware by design. In this paper, the Quality of Experience Centered Design Cycle (QoE-CDC) is proposed, which provides guidelines on how to design applications with respect to network-specific requirements and QoE. Its practical value is showcased for popular application types and validated by outlining the design of a new smartphone application. We show that combining HCDC and QoE-CDC will result in an application design, which reaches a high UX and avoids QoE degradation.
@article{info3-article-2021-6, abstract = {To deliver the best user experience (UX), the human-centered design cycle (HCDC) serves as a well-established guideline to application developers. However, it does not yet cover network-specific requirements, which become increasingly crucial, as most applications deliver experience over the Internet. The missing network-centric view is provided by Quality of Experience (QoE), which could team up with UX towards an improved overall experience. By considering QoE aspects during the development process, it can be achieved that applications become network-aware by design. In this paper, the Quality of Experience Centered Design Cycle (QoE-CDC) is proposed, which provides guidelines on how to design applications with respect to network-specific requirements and QoE. Its practical value is showcased for popular application types and validated by outlining the design of a new smartphone application. We show that combining HCDC and QoE-CDC will result in an application design, which reaches a high UX and avoids QoE degradation.}, author = {Seufert, Anika and Schröder, Svenja and Seufert, Michael}, journal = {SN Computer Science}, keywords = {myown}, month = 9, title = {Delivering User Experience over Networks: Towards a Quality of Experience Centered Design Cycle for Improved Design of Networked Applications}, volume = 2, year = 2021 }
17.
Grigorjew, A., Baier, C., Metzger, F., Hoßfeld, T.: Distributed Implementation of Deterministic Networking in Existing Non-TSN Ethernet Switches. Workshop on Time-sensitive and Deterministic Networking (TsDN) (2021).
[ Abstract ] [ BibTeX ]
 
Deterministic networking is quickly gaining importance, as several domains previously dominated by bus systems are now switching to Ethernet. While standardization efforts, especially from the Time-Sensitive Networking (TSN) group, are ongoing, practical deployments are still far off until configuration guidelines and resource management are able to use these tools to their full potential. As an alternative, this work presents a working implementation of bounded latency with an off-the-shelf non-TSN Ethernet switch. The solution is based on a distributed reservation protocol and admission control. It proves that bounded latency is already possible with simple priority-based transmission, and it provides valuable insights for the development and operation of future real-time networking solutions.
@inproceedings{info3-inproceedings-2021-6, abstract = {Deterministic networking is quickly gaining importance, as several domains previously dominated by bus systems are now switching to Ethernet. While standardization efforts, especially from the Time-Sensitive Networking (TSN) group, are ongoing, practical deployments are still far off until configuration guidelines and resource management are able to use these tools to their full potential. As an alternative, this work presents a working implementation of bounded latency with an off-the-shelf non-TSN Ethernet switch. The solution is based on a distributed reservation protocol and admission control. It proves that bounded latency is already possible with simple priority-based transmission, and it provides valuable insights for the development and operation of future real-time networking solutions.}, author = {Grigorjew, Alexej and Baier, Christian and Metzger, Florian and Hoßfeld, Tobias}, booktitle = {Workshop on Time-sensitive and Deterministic Networking (TsDN)}, keywords = {myown ats-performance ngn}, month = 6, title = {Distributed Implementation of Deterministic Networking in Existing Non-TSN Ethernet Switches}, year = 2021 }
18.
Stauffert, J.-P., Korwisi, K., Niebling, F., Latoschik, M.E.: Ka-Boom!!! Visually Exploring Latency Measurements for XR. Extended Abstracts of the 2021 CHI Conference on Human Factors in Computing Systems. Association for Computing Machinery, Yokohama, Japan (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Latency can be detrimental for the experience of Virtual Reality. High latency can lead to loss of performance and cybersickness. There are simple approaches to measure approximate latency and more elaborated for more insight into latency behavior. Yet there are still researchers who do not measure the latency of the system they are using to conduct VR experiments. This paper provides an illustrated overview of different approaches to measure latency of VR applications, as well as a small decision-making guide to assist in the choice of the measurement method. The visual style offers a more approachable way to understand how to measure latency.
@inproceedings{stauffert_kaboom_2021, abstract = {Latency can be detrimental for the experience of Virtual Reality. High latency can lead to loss of performance and cybersickness. There are simple approaches to measure approximate latency and more elaborated for more insight into latency behavior. Yet there are still researchers who do not measure the latency of the system they are using to conduct VR experiments. This paper provides an illustrated overview of different approaches to measure latency of VR applications, as well as a small decision-making guide to assist in the choice of the measurement method. The visual style offers a more approachable way to understand how to measure latency.}, address = {New York, NY, USA}, author = {Stauffert, Jan-Philipp and Korwisi, Kristof and Niebling, Florian and Latoschik, Marc Erich}, booktitle = {Extended Abstracts of the 2021 CHI Conference on Human Factors in Computing Systems}, keywords = {myown}, publisher = {Association for Computing Machinery}, series = {CHI EA '21}, title = {Ka-Boom!!! Visually Exploring Latency Measurements for XR}, year = 2021 }
19.
Schaper, P., Riedmann, A., Lugrin, B.: Internalisation of Situational Motivation in an E-Learning Scenario Using Gamification. International Conference on Artificial Intelligence in Education (AIED 2021). S. 314–319. Springer (2021).
[ BibTeX ]
 
@inproceedings{schaper2021internalisation, author = {Schaper, Philipp and Riedmann, Anna and Lugrin, Birgit}, booktitle = {International Conference on Artificial Intelligence in Education (AIED 2021)}, keywords = {birgit learning mi myown riedmann schaper}, organization = {Springer}, pages = {314-319}, title = {Internalisation of Situational Motivation in an E-Learning Scenario Using Gamification}, year = 2021 }
20.
Prantl, T., Iffländer, L., Herrnleben, S., Engel, S., Kounev, S., Krupitzer, C.: Performance Impact Analysis of Securing MQTT Using TLS. 2021 ACM/SPEC International Conference on Performance Engineering (ICPE) (2021).
[ BibTeX ]
 
@inproceedings{PrTeIfHeDmKo2021-ICPE-MQTT_TLS, author = {Prantl, Thomas and Iffländer, Lukas and Herrnleben, Stefan and Engel, Simon and Kounev, Samuel and Krupitzer, Christian}, booktitle = {2021 ACM/SPEC International Conference on Performance Engineering (ICPE)}, keywords = {IoT MQTT Performance Pub/Sub Security TLS descartes sss-group t_short myown}, month = {April}, series = {ICPE'21}, title = {Performance Impact Analysis of Securing MQTT Using TLS}, year = 2021 }
21.
Eismann, S., Joel, S., van Eyk, E., Schwinger, M., Grohmann, J., Herbst, N., Abad, C., Iosup, A.: Serverless Applications:Why, When, and How?. IEEE Software. 38, 32–39 (2021).
[ Abstract ] [ BibTeX ] [ URL ]
 
Serverless computing shows good promise for efficiency and ease-of-use. Yet, there are only a few, scattered and sometimes conflicting reports on questions such as Why do so many companies adopt serverless?, When are serverless applications well suited?, and How are serverless applications currently implemented? To address these questions, we analyze 89 serverless applications from open-source projects, industrial sources, academic literature, and scientific computing—the most extensive study to date.
@article{eismann2020serverless, abstract = {Serverless computing shows good promise for efficiency and ease-of-use. Yet, there are only a few, scattered and sometimes conflicting reports on questions such as Why do so many companies adopt serverless?, When are serverless applications well suited?, and How are serverless applications currently implemented? To address these questions, we analyze 89 serverless applications from open-source projects, industrial sources, academic literature, and scientific computing—the most extensive study to date.}, author = {Eismann, Simon and Joel, Scheuner and van Eyk, Erwin and Schwinger, Maximilian and Grohmann, Johannes and Herbst, Nikolas and Abad, Cristina and Iosup, Alexandru}, journal = {IEEE Software}, keywords = {descartes myown select t_journalmagazine}, number = 1, pages = {32–39}, title = {Serverless Applications:Why, When, and How?}, volume = 38, year = 2021 }
22.
Wehner, N., Seufert, M., Schüler, J., Wassermann, S., Casas, P., Hoßfeld, T.: Improving Web QoE Monitoring for Encrypted Network Traffic through Time Series Modeling. ACM SIGMETRICS Performance Evaluation Review. 48, 37–40 (2021).
[ Abstract ] [ BibTeX ]
 
This paper addresses the problem of Quality of Experience (QoE) monitoring for web browsing. In particular, the inference of common Web QoE metrics such as Speed Index (SI) is investigated. Based on a large dataset collected with open web-measurement platforms on different device-types, a unique feature set is designed and used to estimate the RUMSI -- an efficient approximation to SI, with machine-learning based regression and classification approaches. Results indicate that it is possible to estimate the RUMSI accurately, and that in particular, recurrent neural networks are highly suitable for the task, as they capture the network dynamics more precisely.
@article{info3-article-2020-4, abstract = {This paper addresses the problem of Quality of Experience (QoE) monitoring for web browsing. In particular, the inference of common Web QoE metrics such as Speed Index (SI) is investigated. Based on a large dataset collected with open web-measurement platforms on different device-types, a unique feature set is designed and used to estimate the RUMSI – an efficient approximation to SI, with machine-learning based regression and classification approaches. Results indicate that it is possible to estimate the RUMSI accurately, and that in particular, recurrent neural networks are highly suitable for the task, as they capture the network dynamics more precisely.}, author = {Wehner, Nikolas and Seufert, Michael and Schüler, Joshua and Wassermann, Sarah and Casas, Pedro and Hoßfeld, Tobias}, journal = {ACM SIGMETRICS Performance Evaluation Review}, keywords = {myown ucn copy}, month = 3, number = 4, pages = {37-40}, title = {Improving Web QoE Monitoring for Encrypted Network Traffic through Time Series Modeling}, volume = 48, year = 2021 }
23.
Wienrich, C., Döllinger, N.I., Hein, R.: Behavioral Framework of Immersive Technologies (BehaveFIT): How and Why Virtual Reality can Support Behavioral Change Processes. Frontiers Virtual Reality. 2, 84 (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
The design and evaluation of assisting technologies to support behavior change processes have become an essential topic within the field of human-computer interaction research in general and the field of immersive intervention technologies in particular. The mechanisms and success of behavior change techniques and interventions are broadly investigated in the field of psychology. However, it is not always easy to adapt these psychological findings to the context of immersive technologies. The lack of theoretical foundation also leads to a lack of explanation as to why and how immersive interventions support behavior change processes. The Behavioral Framework for immersive Technologies (BehaveFIT) addresses this lack by 1) presenting an intelligible categorization and condensation of psychological barriers and immersive features, by 2) suggesting a mapping that shows why and how immersive technologies can help to overcome barriers and finally by 3) proposing a generic prediction path that enables a structured, theory-based approach to the development and evaluation of immersive interventions. These three steps explain how BehaveFIT can be used, and include guiding questions for each step. Further, two use cases illustrate the usage of BehaveFIT. Thus, the present paper contributes to guidance for immersive intervention design and evaluation, showing that immersive interventions support behavior change processes and explain and predict 'why' and 'how' immersive interventions can bridge the intention-behavior-gap.
@article{wienrich2020mind, abstract = {The design and evaluation of assisting technologies to support behavior change processes have become an essential topic within the field of human-computer interaction research in general and the field of immersive intervention technologies in particular. The mechanisms and success of behavior change techniques and interventions are broadly investigated in the field of psychology. However, it is not always easy to adapt these psychological findings to the context of immersive technologies. The lack of theoretical foundation also leads to a lack of explanation as to why and how immersive interventions support behavior change processes. The Behavioral Framework for immersive Technologies (BehaveFIT) addresses this lack by 1) presenting an intelligible categorization and condensation of psychological barriers and immersive features, by 2) suggesting a mapping that shows why and how immersive technologies can help to overcome barriers and finally by 3) proposing a generic prediction path that enables a structured, theory-based approach to the development and evaluation of immersive interventions. These three steps explain how BehaveFIT can be used, and include guiding questions for each step. Further, two use cases illustrate the usage of BehaveFIT. Thus, the present paper contributes to guidance for immersive intervention design and evaluation, showing that immersive interventions support behavior change processes and explain and predict 'why' and 'how' immersive interventions can bridge the intention-behavior-gap.}, author = {Wienrich, Carolin and D{ö}llinger, Nina Ines and Hein, Rebecca}, journal = {Frontiers Virtual Reality}, keywords = {myown rebecca.hein rhein}, pages = 84, title = {Behavioral Framework of Immersive Technologies (BehaveFIT): How and Why Virtual Reality can Support Behavioral Change Processes}, volume = 2, year = 2021 }
24.
Geissler, S., Wamser, F., Bauer, W., Krolikowski, M., Gebert, S., Hoßfeld, T.: Signaling Traffic in Internet-of-Things Mobile Networks. IFIP/IEEE International Symposium on Integrated Network Management (IM 2021). , Bordeaux, France (Virtual Conference) (2021).
[ Abstract ] [ BibTeX ]
 
The Internet of Things (IoT) is expected to play an increasingly important role in next-generation mobile networks. Detailed knowledge of this type of traffic and the associated signaling in those networks is of interest to operators and standardization in order to run these networks successfully. The aim of this study is to characterize IoT signaling traffic for mobile communication networks (i) from a network operator’s point of view, (ii) at device level, and (iii) for the establishment of data connections. General statistics on signaling and device behavior, such as the observed IoT traffic volume and message composition, are given before device classes with statistically different signaling behavior are identified. Finally, by characterizing the aggre- gated signaling traffic, we show that the Markov assumption, widespread in standardization and literature, regarding the aggregated arrival process for data connections does not apply in reality.
@inproceedings{info3-inproceedings-2021-1, abstract = {The Internet of Things (IoT) is expected to play an increasingly important role in next-generation mobile networks. Detailed knowledge of this type of traffic and the associated signaling in those networks is of interest to operators and standardization in order to run these networks successfully. The aim of this study is to characterize IoT signaling traffic for mobile communication networks (i) from a network operator’s point of view, (ii) at device level, and (iii) for the establishment of data connections. General statistics on signaling and device behavior, such as the observed IoT traffic volume and message composition, are given before device classes with statistically different signaling behavior are identified. Finally, by characterizing the aggre- gated signaling traffic, we show that the Markov assumption, widespread in standardization and literature, regarding the aggregated arrival process for data connections does not apply in reality.}, address = {Bordeaux, France (Virtual Conference)}, author = {Geissler, Stefan and Wamser, Florian and Bauer, Wolfang and Krolikowski, Michael and Gebert, Steffen and Hoßfeld, Tobias}, booktitle = {IFIP/IEEE International Symposium on Integrated Network Management (IM 2021)}, keywords = {myown 5cale can}, month = 5, title = {Signaling Traffic in Internet-of-Things Mobile Networks}, year = 2021 }
25.
Wolf, E., Merdan, N., Döllinger, N., Mal, D., Wienrich, C., Botsch, M., Latoschik, M.E.: The Embodiment of Photorealistic Avatars Influences Female Body Weight Perception in Virtual Reality. Proceedings of the 28th IEEE Virtual Reality Conference (VR ’21). S. 65–74 (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Embodiment and body perception have become important research topics in the field of virtual reality (VR). VR is considered a particularly promising tool to support research and therapy in regard to distorted body weight perception. However, the influence of embodiment on body weight perception has yet to be clarified. To address this gap, we compared body weight perception of 56 female participants of normal weight using a VR application. They either (a) self-embodied a photorealistic, non-personalized virtual human and performed body movements in front of a virtual mirror or (b) only observed the virtual human as other's avatar (or agent) performing the same movements in front of them. Afterward, participants had to estimate the virtual human's body weight. Additionally, we considered the influence of the participants' body mass index (BMI) on the estimations and captured the participants' feelings of presence and embodiment. Participants estimated the body weight of the virtual human as their embodied self-avatars significantly lower compared to participants rating the virtual human as other's avatar. Furthermore, the estimations of body weight were significantly predicted by the participant's BMI with embodiment, but not without. Our results clearly highlight embodiment as an important factor influencing the perception of virtual humans' body weights in VR.
@inproceedings{wolf2021embodiment, abstract = {Embodiment and body perception have become important research topics in the field of virtual reality (VR). VR is considered a particularly promising tool to support research and therapy in regard to distorted body weight perception. However, the influence of embodiment on body weight perception has yet to be clarified. To address this gap, we compared body weight perception of 56 female participants of normal weight using a VR application. They either (a) self-embodied a photorealistic, non-personalized virtual human and performed body movements in front of a virtual mirror or (b) only observed the virtual human as other's avatar (or agent) performing the same movements in front of them. Afterward, participants had to estimate the virtual human's body weight. Additionally, we considered the influence of the participants' body mass index (BMI) on the estimations and captured the participants' feelings of presence and embodiment. Participants estimated the body weight of the virtual human as their embodied self-avatars significantly lower compared to participants rating the virtual human as other's avatar. Furthermore, the estimations of body weight were significantly predicted by the participant's BMI with embodiment, but not without. Our results clearly highlight embodiment as an important factor influencing the perception of virtual humans' body weights in VR.}, author = {Wolf, Erik and Merdan, Nathalie and Döllinger, Nina and Mal, David and Wienrich, Carolin and Botsch, Mario and Latoschik, Marc Erich}, booktitle = {Proceedings of the 28th IEEE Virtual Reality Conference (VR '21)}, keywords = {ewolf myown vitras}, pages = {65-74}, title = {The Embodiment of Photorealistic Avatars Influences Female Body Weight Perception in Virtual Reality}, year = 2021 }
26.
Prantl, T., Ten, P., Iffländer, L., Herrnleben, S., Dmitrenko, A., Kounev, S., Krupitzer, C.: Towards a Group Encryption Scheme Benchmark: A View on Centralized Schemes with focus on IoT. 2021 ACM/SPEC International Conference on Performance Engineering (ICPE) (2021).
[ BibTeX ]
 
@inproceedings{PrTeIfHeDmKo2021-ICPE-GroupEncryptionCentralizedBenchmark, author = {Prantl, Thomas and Ten, Peter and Iffländer, Lukas and Herrnleben, Stefan and Dmitrenko, Alexandra and Kounev, Samuel and Krupitzer, Christian}, booktitle = {2021 ACM/SPEC International Conference on Performance Engineering (ICPE)}, keywords = {Benchmark Energy\_Efficiency Group\_Encyrption\_Scheme Security descartes sss-group t_short myown}, month = {April}, series = {ICPE'21}, title = {Towards a Group Encryption Scheme Benchmark: A View on Centralized Schemes with focus on IoT}, year = 2021 }
27.
Wehner, N., Seufert, M., Wieser, V., Casas, P., Capdehourat, G.: Quality that Matters: QoE Monitoring in Education Service Provider (ESP) Networks. IFIP/IEEE International Symposium on Integrated Network Management (IM 2021). , Bordeaux, France (Virtual Conference) (2021).
[ Abstract ] [ BibTeX ]
 
Education Service Providers (ESPs) play a crucial role in the digitization of education as they equip students and teachers with reliable devices and provide high quality Internet access at schools. This paper investigates four months worth of continuous measurements conducted by an ESP using a largescale, passive, in-device Quality of Experience (QoE) monitoring system deployed into a nationwide network of education-purpose devices. These measurements cover more than 800 education centers and about 4000 devices, used both in schools and at home. Using this rich dataset, we present an exhaustive characterization of the browsing behavior, and a quantification of the web and video QoE in this educational context. Web QoE results showed a better performance for school Wi-Fi networks compared to home connections, suggesting that several issues may arise for ESPs due to the increasing relevance of home-schooling caused by the COVID-19 pandemic.
@inproceedings{info3-inproceedings-2021-3, abstract = {Education Service Providers (ESPs) play a crucial role in the digitization of education as they equip students and teachers with reliable devices and provide high quality Internet access at schools. This paper investigates four months worth of continuous measurements conducted by an ESP using a largescale, passive, in-device Quality of Experience (QoE) monitoring system deployed into a nationwide network of education-purpose devices. These measurements cover more than 800 education centers and about 4000 devices, used both in schools and at home. Using this rich dataset, we present an exhaustive characterization of the browsing behavior, and a quantification of the web and video QoE in this educational context. Web QoE results showed a better performance for school Wi-Fi networks compared to home connections, suggesting that several issues may arise for ESPs due to the increasing relevance of home-schooling caused by the COVID-19 pandemic.}, address = {Bordeaux, France (Virtual Conference)}, author = {Wehner, Nikolas and Seufert, Michael and Wieser, Viktoria and Casas, Pedro and Capdehourat, Germán}, booktitle = {IFIP/IEEE International Symposium on Integrated Network Management (IM 2021)}, keywords = {myown ucn}, month = 5, title = {Quality that Matters: QoE Monitoring in Education Service Provider (ESP) Networks}, year = 2021 }
28.
Chaplick, S., Kindermann, P., Klawitter, J., Rutter, I., Wolff, A.: Extending Partial Representations of Rectangular Duals with Given Contact Orientations. In: Philippou, A. und Georgiou, C. (hrsg.) Proceedings of the 12th International Conference on Algorithms and Complexity (CIAC’21) (2021).
[ Abstract ] [ BibTeX ]
 
A rectangular dual of a graph G is a contact representation of G with axis-aligned rectangles such that (i) no four rectangles share a point and (ii) the union of all rectangles is a rectangle. The partial representation extension problem for rectangular duals asks whether a given partial rectangular dual can be extended to a rectangular dual, that is, whether there exists a rectangular dual where some vertices are represented by prescribed rectangles. Combinatorially, a rectangular dual can be described by a regular edge labeling (REL), which determines the orientations of the rectangle contacts. We characterize the RELs that admit an extension, which leads to a linear-time testing algorithm. In the affirmative, we can construct an extension in linear time.
@inproceedings{ckkrw-eprrd-ciac21, abstract = {A rectangular dual of a graph G is a contact representation of G with axis-aligned rectangles such that (i) no four rectangles share a point and (ii) the union of all rectangles is a rectangle. The partial representation extension problem for rectangular duals asks whether a given partial rectangular dual can be extended to a rectangular dual, that is, whether there exists a rectangular dual where some vertices are represented by prescribed rectangles. Combinatorially, a rectangular dual can be described by a regular edge labeling (REL), which determines the orientations of the rectangle contacts. We characterize the RELs that admit an extension, which leads to a linear-time testing algorithm. In the affirmative, we can construct an extension in linear time.}, author = {Chaplick, Steven and Kindermann, Philipp and Klawitter, Jonathan and Rutter, Ignaz and Wolff, Alexander}, booktitle = {Proceedings of the 12th International Conference on Algorithms and Complexity (CIAC'21)}, editor = {Philippou, Anna and Georgiou, Chryssis}, keywords = {myown}, note = {To appear}, title = {Extending Partial Representations of Rectangular Duals with Given Contact Orientations}, year = 2021 }
29.
Grohmann, J., Straesser, M., Chalbani, A., Eismann, S., Arian, Y., Herbst, N., Peretz, N., Kounev, S.: SuanMing: Explainable Prediction of Performance Degradations in Microservice Applications. Proceedings of the 12th ACM/SPEC International Conference on Performance Engineering (ICPE). ACM, New York, NY, USA (2021).
[ Abstract ] [ BibTeX ] [ URL ]
 
Application performance management (APM) tools are useful to observe the performance properties of an application during production. However, APM is normally purely reactive, that is, it can only report about current or past performance degradation. Although some approaches capable of predictive application monitoring have been proposed, they can only report a predicted degradation but cannot explain its root-cause, making it hard to prevent the expected degradation. In this paper, we present SuanMing---a framework for predicting performance degradation of microservice applications running in cloud environments. SuanMing is able to predict future root causes for anticipated performance degradations and therefore aims at preventing performance degradations before they actually occur. We evaluate SuanMing on two realistic microservice applications, TeaStore and TrainTicket, and we show that our approach is able to predict and pinpoint performance degradations with an accuracy of over 90%.
@inproceedings{GrStChEiArHePeKo2021-ICPE, abstract = {Application performance management (APM) tools are useful to observe the performance properties of an application during production. However, APM is normally purely reactive, that is, it can only report about current or past performance degradation. Although some approaches capable of predictive application monitoring have been proposed, they can only report a predicted degradation but cannot explain its root-cause, making it hard to prevent the expected degradation. In this paper, we present SuanMing—a framework for predicting performance degradation of microservice applications running in cloud environments. SuanMing is able to predict future root causes for anticipated performance degradations and therefore aims at preventing performance degradations before they actually occur. We evaluate SuanMing on two realistic microservice applications, TeaStore and TrainTicket, and we show that our approach is able to predict and pinpoint performance degradations with an accuracy of over 90\%.}, address = {New York, NY, USA}, author = {Grohmann, Johannes and Straesser, Martin and Chalbani, Avi and Eismann, Simon and Arian, Yair and Herbst, Nikolas and Peretz, Noam and Kounev, Samuel}, booktitle = {Proceedings of the 12th ACM/SPEC International Conference on Performance Engineering (ICPE)}, keywords = {descartes performance prediction statistical_estimation_and_machine_learning t_full myown}, month = {April}, note = {Acceptance Rate: 29%}, organization = {ACM}, title = {SuanMing: Explainable Prediction of Performance Degradations in Microservice Applications}, year = 2021 }
30.
Hamzeheinejad, N., Roth, D., Monty, S., Breuer, J., Rodenberg, A., Latoschik, M.E.: The Impact of Implicit and Explicit Feedback on Performance and Experience during VR-Supported Motor Rehabilitation. 2021 IEEE Virtual Reality and 3D User Interfaces (VR). S. 382–391. IEEE (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
This paper examines the impact of implicit and explicit feedback in Virtual Reality (VR) on performance and user experience during motor rehabilitation. In this work, explicit feedback consists of visual and auditory cues provided by a virtual trainer, compared to traditional feedback provided by a real physiotherapist. Implicit feedback was generated by the walking motion of the virtual trainer accompanying the patient during virtual walks. Here, the potential synchrony of movements between the trainer and trainee is intended to create an implicit visual affordance of motion adaption. We hypothesize that this will stimulate the activation of mirror neurons, thus fostering neuroadaptive processes. We conducted a clinical user study in a rehabilitation center employing a gait robot. We investigated the performance outcome and subjective experience of four resulting VR-supported rehabilitation conditions: with/without explicit feedback, and with/without implicit (synchronous motion) stimulation by a virtual trainer. We further included two baseline conditions reflecting the current NonVR procedure in the rehabilitation center. Our results show that additional feedback generally resulted in better patient performance, objectively assessed by the necessary applied support force of the robot. Additionally, our VR supported rehabilitation procedure improved enjoyment and satisfaction, while no negative impacts could be observed. Implicit feedback and adapted motion synchrony by the virtual trainer led to higher mental demand, giving rise to hopes of increased neural activity and neuroadaptive stimulation.
@inproceedings{hamzeheinejad2021impact, abstract = {This paper examines the impact of implicit and explicit feedback in Virtual Reality (VR) on performance and user experience during motor rehabilitation. In this work, explicit feedback consists of visual and auditory cues provided by a virtual trainer, compared to traditional feedback provided by a real physiotherapist. Implicit feedback was generated by the walking motion of the virtual trainer accompanying the patient during virtual walks. Here, the potential synchrony of movements between the trainer and trainee is intended to create an implicit visual affordance of motion adaption. We hypothesize that this will stimulate the activation of mirror neurons, thus fostering neuroadaptive processes. We conducted a clinical user study in a rehabilitation center employing a gait robot. We investigated the performance outcome and subjective experience of four resulting VR-supported rehabilitation conditions: with/without explicit feedback, and with/without implicit (synchronous motion) stimulation by a virtual trainer. We further included two baseline conditions reflecting the current NonVR procedure in the rehabilitation center. Our results show that additional feedback generally resulted in better patient performance, objectively assessed by the necessary applied support force of the robot. Additionally, our VR supported rehabilitation procedure improved enjoyment and satisfaction, while no negative impacts could be observed. Implicit feedback and adapted motion synchrony by the virtual trainer led to higher mental demand, giving rise to hopes of increased neural activity and neuroadaptive stimulation.}, author = {Hamzeheinejad, Negin and Roth, Daniel and Monty, Samantha and Breuer, Julian and Rodenberg, Anuschka and Latoschik, Marc Erich}, booktitle = {2021 IEEE Virtual Reality and 3D User Interfaces (VR)}, keywords = {myown vrgait}, pages = {382-391}, publisher = {IEEE}, title = {The Impact of Implicit and Explicit Feedback on Performance and Experience during VR-Supported Motor Rehabilitation}, year = 2021 }
31.
Geissler, S., Lange, S., Tran-Gia, P., Hoßfeld, T.: Discrete-time Analysis of Multicomponent GI/GI/1 Queueing Networks. Conference on Networked Systems (NetSys) (2021).
[ Abstract ] [ BibTeX ]
 
In this work, we provide initial insights regarding the error introduced into multicomponent queueing systems by assuming the departure processes of arbitrary GI/GI/1-∞ queues to be renewal processes. To this end, we compute the sojourn time distribution as well as departure distributions of a linear chain of queueing components and compare the results to a simulation of the same system. By applying the renewal approximation, potential autocorrelations of the departure processes are lost. We investigate the magnitude of this error regarding both the sojourn time as well as interdeparture time distributions for a broad set of parameters. Although more indepth studies are needed, our results show that both distributions can be closely approximated, which allows the application of the model to asses the performance of real world NFV function chains.
@inproceedings{info3-inproceedings-2021-4, abstract = {In this work, we provide initial insights regarding the error introduced into multicomponent queueing systems by assuming the departure processes of arbitrary GI/GI/1-∞ queues to be renewal processes. To this end, we compute the sojourn time distribution as well as departure distributions of a linear chain of queueing components and compare the results to a simulation of the same system. By applying the renewal approximation, potential autocorrelations of the departure processes are lost. We investigate the magnitude of this error regarding both the sojourn time as well as interdeparture time distributions for a broad set of parameters. Although more indepth studies are needed, our results show that both distributions can be closely approximated, which allows the application of the model to asses the performance of real world NFV function chains.}, author = {Geissler, Stefan and Lange, Stanislav and Tran-Gia, Phuoc and Hoßfeld, Tobias}, booktitle = {Conference on Networked Systems (NetSys)}, keywords = {myown}, month = 11, title = {Discrete-time Analysis of Multicomponent GI/GI/1 Queueing Networks}, year = 2021 }
32.
Oberdörfer, S., Heidrich, D., Birnstiel, S., Latoschik, M.E.: Measuring the Effects of Virtual Environment Design on Decision-Making. Proceedings of the 28th IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VR ’21). S. 442–443. IEEE (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@inproceedings{oberdorfer2021measuring, author = {Oberdörfer, Sebastian and Heidrich, David and Birnstiel, Sandra and Latoschik, Marc Erich}, booktitle = {Proceedings of the 28th IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VR '21)}, keywords = {myown oberdoerfer}, month = {March}, organization = {IEEE}, pages = {442-443}, title = {Measuring the Effects of Virtual Environment Design on Decision-Making}, year = 2021 }
33.
Oberdörfer, S., Straka, S., Latoschik, M.E.: Effects of Immersion and Visual Angle on Brand Placement Effectiveness. Proceedings of the 28th IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VR ’21). S. 440–441. IEEE (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@inproceedings{oberdorfer2021effects, author = {Oberdörfer, Sebastian and Straka, Samantha and Latoschik, Marc Erich}, booktitle = {Proceedings of the 28th IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VR '21)}, keywords = {myown oberdoerfer}, month = {March}, organization = {IEEE}, pages = {440-441}, title = {Effects of Immersion and Visual Angle on Brand Placement Effectiveness}, year = 2021 }
34.
Bartl, A., Jung, S., Kullmann, P., Wenninger, S., Achenbach, J., Wolf, E., Schell, C., Lindeman, R.W., Botsch, M., Latoschik, M.E.: Self-Avatars in Virtual Reality: A Study Protocol for Investigating the Impact of the Deliberateness of Choice and the Context-Match. Proceedings of the 28th IEEE Virtual Reality conference (VR ’21). IEEE (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@inproceedings{bartl2021selfavatars, author = {Bartl, Andrea and Jung, Sungchul and Kullmann, Peter and Wenninger, Stephan and Achenbach, Jascha and Wolf, Erik and Schell, Christian and Lindeman, Robert W. and Botsch, Mario and Latoschik, Marc Erich}, booktitle = {Proceedings of the 28th IEEE Virtual Reality conference (VR '21)}, keywords = {ewolf myown}, month = {March}, organization = {IEEE}, title = {Self-Avatars in Virtual Reality: A Study Protocol for Investigating the Impact of the Deliberateness of Choice and the Context-Match}, year = 2021 }
35.
Treff, G., Leppich, R., Winkert, K., Steinacker, J.M., Mayer, B., Sperlich, B.: The integration of training and off-training activities substantially alters training volume and load analysis in elite rowers. Scientific reports. 11, 1–10 (2021).
[ BibTeX ]
 
@article{treff2021integration, author = {Treff, Gunnar and Leppich, Robert and Winkert, Kay and Steinacker, J{ü}rgen M and Mayer, Benjamin and Sperlich, Billy}, journal = {Scientific reports}, keywords = {descartes t_interdisciplinary t_journalmagazine myown}, number = 1, pages = {1–10}, publisher = {Nature Publishing Group}, title = {The integration of training and off-training activities substantially alters training volume and load analysis in elite rowers}, volume = 11, year = 2021 }
36.
Schaper, P., Donnermann, M., Doser, N., Lein, M., Riedmann, A., Steinhaeusser, S.C., Karageorgos, P., Müller, B., Richter, T., Lugrin, B.: Towards a digital syllable-based reading intervention: An interview study with second-graders. British HCI Conference 2021 (BCS-HCI 2021) (2021).
[ BibTeX ]
 
@inproceedings{schaper2021towards, author = {Schaper, Philipp and Donnermann, Melissa and Doser, Nicole and Lein, Martina and Riedmann, Anna and Steinhaeusser, Sophia C. and Karageorgos, Panagiotis and Müller, Bettina and Richter, Tobias and Lugrin, Birgit}, booktitle = {British HCI Conference 2021 (BCS-HCI 2021)}, keywords = {birgit donnermann learning lein mi myown riedmann schaper steinhaeusser}, title = {Towards a digital syllable-based reading intervention: An interview study with second-graders}, year = 2021 }
37.
Grigorjew, A., Seufert, M., Wehner, N., Hofmann, J., Hoßfeld, T.: ML-Assisted Latency Assignments in Time-Sensitive Networking. IFIP/IEEE International Symposium on Integrated Network Management (IM 2021). , Bordeaux, France (Virtual Conference) (2021).
[ Abstract ] [ BibTeX ]
 
Recent developments in industrial automation and invehicle communication have raised the requirements of real-time networking. Bus systems that were traditionally deployed in these fields cannot provide sufficient bandwidth and are now shifting towards Ethernet for their real-time communication needs. In this field, standardization efforts from the IEEE and the IETF have developed new data plane mechanisms such as shapers and schedulers, as well as control plane mechanisms such as reservation protocols to support their new requirements. However, their implementation and their optimal configuration remain an important factor for their efficiency. This work presents a machine learning framework that takes on the configuration task. Four different models are trained for the configuration of per-hop latency guarantees in a distributed resource reservation process and compared with respect to their real-time traffic capacity. The evaluation shows that all models provide good configurations for the provided scenarios, but more importantly, they represent a first step for a semi-automated configuration of parameters in Time-Sensitive Networking.
@inproceedings{info3-inproceedings-2021-2, abstract = {Recent developments in industrial automation and invehicle communication have raised the requirements of real-time networking. Bus systems that were traditionally deployed in these fields cannot provide sufficient bandwidth and are now shifting towards Ethernet for their real-time communication needs. In this field, standardization efforts from the IEEE and the IETF have developed new data plane mechanisms such as shapers and schedulers, as well as control plane mechanisms such as reservation protocols to support their new requirements. However, their implementation and their optimal configuration remain an important factor for their efficiency. This work presents a machine learning framework that takes on the configuration task. Four different models are trained for the configuration of per-hop latency guarantees in a distributed resource reservation process and compared with respect to their real-time traffic capacity. The evaluation shows that all models provide good configurations for the provided scenarios, but more importantly, they represent a first step for a semi-automated configuration of parameters in Time-Sensitive Networking.}, address = {Bordeaux, France (Virtual Conference)}, author = {Grigorjew, Alexej and Seufert, Michael and Wehner, Nikolas and Hofmann, Jan and Hoßfeld, Tobias}, booktitle = {IFIP/IEEE International Symposium on Integrated Network Management (IM 2021)}, keywords = {myown kikdin}, month = 5, title = {ML-Assisted Latency Assignments in Time-Sensitive Networking}, year = 2021 }
38.
Obremski, D., Lugrin, J.-L., Schaper, P., Lugrin, B.: Non-native speaker perception of Intelligent Virtual Agents in two languages: the impact of amount and type of grammatical mistakes. Journal on Multimodal User Interfaces. (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Having a mixed-cultural membership becomes increasingly common in our modern society. It is thus beneficial in several ways to create Intelligent Virtual Agents (IVAs) that reflect a mixed-cultural background as well, e.g., for educational settings. For research with such IVAs, it is essential that they are classified as non-native by members of a target culture. In this paper, we focus on variations of IVAs' speech to create the impression of non-native speakers that are identified as such by speakers of two different mother tongues. In particular, we investigate grammatical mistakes and identify thresholds beyond which the agents is clearly categorised as a non-native speaker. Therefore, we conducted two experiments: one for native speakers of German, and one for native speakers of English. Results of the German study indicate that beyond 10% of word order mistakes and 25% of infinitive mistakes German-speaking IVAs are perceived as non-native speakers. Results of the English study indicate that beyond 50% of omission mistakes and 50% of infinitive mistakes English-speaking IVAs are perceived as non-native speakers. We believe these thresholds constitute helpful guidelines for computational approaches of non-native speaker generation, simplifying research with IVAs in mixed-cultural settings.
@article{Obremski2021, abstract = {Having a mixed-cultural membership becomes increasingly common in our modern society. It is thus beneficial in several ways to create Intelligent Virtual Agents (IVAs) that reflect a mixed-cultural background as well, e.g., for educational settings. For research with such IVAs, it is essential that they are classified as non-native by members of a target culture. In this paper, we focus on variations of IVAs' speech to create the impression of non-native speakers that are identified as such by speakers of two different mother tongues. In particular, we investigate grammatical mistakes and identify thresholds beyond which the agents is clearly categorised as a non-native speaker. Therefore, we conducted two experiments: one for native speakers of German, and one for native speakers of English. Results of the German study indicate that beyond 10{\%} of word order mistakes and 25{\%} of infinitive mistakes German-speaking IVAs are perceived as non-native speakers. Results of the English study indicate that beyond 50{\%} of omission mistakes and 50{\%} of infinitive mistakes English-speaking IVAs are perceived as non-native speakers. We believe these thresholds constitute helpful guidelines for computational approaches of non-native speaker generation, simplifying research with IVAs in mixed-cultural settings.}, author = {Obremski, David and Lugrin, Jean-Luc and Schaper, Philipp and Lugrin, Birgit}, journal = {Journal on Multimodal User Interfaces}, keywords = {IVA birgit lugrin mi myown obremski schaper}, title = {Non-native speaker perception of Intelligent Virtual Agents in two languages: the impact of amount and type of grammatical mistakes}, year = 2021 }
39.
Unruh, F., Landeck, M., Oberdörfer, S., Lugrin, J.-L., Latoschik, M.E.: The Influence of Avatar Embodiment on Time Perception - Towards VR for Time-Based Therapy. Frontiers in Virtual Reality. 2, 71 (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Psycho-pathological conditions, such as depression or schizophrenia, are often accompanied by a distorted perception of time. People suffering from this conditions often report that the passage of time slows down considerably and that they are ``stuck in time.'' Virtual Reality (VR) could potentially help to diagnose and maybe treat such mental conditions. However, the conditions in which a VR simulation could correctly diagnose a time perception deviation are still unknown. In this paper, we present an experiment investigating the difference in time experience with and without a virtual body in VR, also known as avatar. The process of substituting a person's body with a virtual body is called avatar embodiment. Numerous studies demonstrated interesting perceptual, emotional, behavioral, and psychological effects caused by avatar embodiment. However, the relations between time perception and avatar embodiment are still unclear. Whether or not the presence or absence of an avatar is already influencing time perception is still open to question. Therefore, we conducted a between-subjects design with and without avatar embodiment as well as a real condition (avatar vs. no-avatar vs. real). A group of 105 healthy subjects had to wait for seven and a half minutes in a room without any distractors (e.g., no window, magazine, people, decoration) or time indicators (e.g., clocks, sunlight). The virtual environment replicates the real physical environment. Participants were unaware that they will be asked to estimate their waiting time duration as well as describing their experience of the passage of time at a later stage. Our main finding shows that the presence of an avatar is leading to a significantly faster perceived passage of time. It seems to be promising to integrate avatar embodiment in future VR time-based therapy applications as they potentially could modulate a user's perception of the passage of time. We also found no significant difference in time perception between the real and the VR conditions (avatar, no-avatar), but further research is needed to better understand this outcome.
@article{10.3389/frvir.2021.658509, abstract = {Psycho-pathological conditions, such as depression or schizophrenia, are often accompanied by a distorted perception of time. People suffering from this conditions often report that the passage of time slows down considerably and that they are ``stuck in time.'' Virtual Reality (VR) could potentially help to diagnose and maybe treat such mental conditions. However, the conditions in which a VR simulation could correctly diagnose a time perception deviation are still unknown. In this paper, we present an experiment investigating the difference in time experience with and without a virtual body in VR, also known as avatar. The process of substituting a person's body with a virtual body is called avatar embodiment. Numerous studies demonstrated interesting perceptual, emotional, behavioral, and psychological effects caused by avatar embodiment. However, the relations between time perception and avatar embodiment are still unclear. Whether or not the presence or absence of an avatar is already influencing time perception is still open to question. Therefore, we conducted a between-subjects design with and without avatar embodiment as well as a real condition (avatar vs. no-avatar vs. real). A group of 105 healthy subjects had to wait for seven and a half minutes in a room without any distractors (e.g., no window, magazine, people, decoration) or time indicators (e.g., clocks, sunlight). The virtual environment replicates the real physical environment. Participants were unaware that they will be asked to estimate their waiting time duration as well as describing their experience of the passage of time at a later stage. Our main finding shows that the presence of an avatar is leading to a significantly faster perceived passage of time. It seems to be promising to integrate avatar embodiment in future VR time-based therapy applications as they potentially could modulate a user's perception of the passage of time. We also found no significant difference in time perception between the real and the VR conditions (avatar, no-avatar), but further research is needed to better understand this outcome.}, author = {Unruh, Fabian and Landeck, Maximilian and Oberd{ö}rfer, Sebastian and Lugrin, Jean-Luc and Latoschik, Marc Erich}, journal = {Frontiers in Virtual Reality}, keywords = {hci-uwb myown vtimes}, pages = 71, title = {The Influence of Avatar Embodiment on Time Perception - Towards VR for Time-Based Therapy}, volume = 2, year = 2021 }
40.
Dallmann, A., Zoller, D., Hotho, A.: A Case Study on Sampling Strategies for Evaluating Neural Sequential Item Recommendation Models. Fifteenth ACM Conference on Recommender Systems. ACM (2021).
[ BibTeX ] [ DOI ]
 
@inproceedings{dallmann2021study, author = {Dallmann, Alexander and Zoller, Daniel and Hotho, Andreas}, booktitle = {Fifteenth {ACM} Conference on Recommender Systems}, keywords = {2021 deep evaluation learning myown recommender sampling systems}, month = {sep}, publisher = {{ACM}}, title = {A Case Study on Sampling Strategies for Evaluating Neural Sequential Item Recommendation Models}, year = 2021 }
41.
Fischer, E., Zoller, D., Hotho, A.: Comparison of Transformer-Based Sequential Product Recommendation Models for the Coveo Data Challenge. SIGIR Workshop On eCommerce. (2021).
[ BibTeX ]
 
@article{fischer2021comparison, author = {Fischer, Elisabeth and Zoller, Daniel and Hotho, Andreas}, journal = {SIGIR Workshop On eCommerce}, keywords = {2021 myown product recommendation transformer}, month = {July}, title = {Comparison of Transformer-Based Sequential Product Recommendation Models for the Coveo Data Challenge}, year = 2021 }
42.
Steininger, M., Kobs, K., Davidson, P., Krause, A., Hotho, A.: Density-based weighting for imbalanced regression. Machine Learning. (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
In many real world settings,imbalanced data impedes model performance of learning algorithms, like neural networks, mostly for rare cases. This is especially problematic for tasks focusing on these rare occurrences. For example, when estimating precipitation, extreme rainfall events are scarce but important considering their potential consequences. While there are numerous well studied solutions for classification settings, most of them cannot be applied to regression easily. Of the few solutions for regression tasks, barely any have explored cost-sensitive learning which is known to have advantages compared to sampling-based methods in classification tasks. In this work, we propose a sample weighting approach for imbalanced regression datasets called DenseWeight and a cost-sensitive learning approach for neural network regression with imbalanced data called DenseLoss based on our weighting scheme. DenseWeight weights data points according to their target value rarities through kernel density estimation (KDE). DenseLoss adjusts each data point’s influence on the loss according to DenseWeight, giving rare data points more influence on modeltraining compared to common data points. We show on multiple differently distributed datasets that DenseLoss significantly improves model performance for rare data points through its density-based weighting scheme. Additionally, we compare DenseLoss to the state-of-the-art method SMOGN, finding that our method mostly yields better performance. Our approach provides more control over model training as it enables us to actively decide on the trade-off between focusing on common or rare cases through a single hyperparameter, allowing the training of better models for rare data points.
@article{steininger2021densitybased, abstract = {In many real world settings,imbalanced data impedes model performance of learning algorithms, like neural networks, mostly for rare cases. This is especially problematic for tasks focusing on these rare occurrences. For example, when estimating precipitation, extreme rainfall events are scarce but important considering their potential consequences. While there are numerous well studied solutions for classification settings, most of them cannot be applied to regression easily. Of the few solutions for regression tasks, barely any have explored cost-sensitive learning which is known to have advantages compared to sampling-based methods in classification tasks. In this work, we propose a sample weighting approach for imbalanced regression datasets called DenseWeight and a cost-sensitive learning approach for neural network regression with imbalanced data called DenseLoss based on our weighting scheme. DenseWeight weights data points according to their target value rarities through kernel density estimation (KDE). DenseLoss adjusts each data point’s influence on the loss according to DenseWeight, giving rare data points more influence on modeltraining compared to common data points. We show on multiple differently distributed datasets that DenseLoss significantly improves model performance for rare data points through its density-based weighting scheme. Additionally, we compare DenseLoss to the state-of-the-art method SMOGN, finding that our method mostly yields better performance. Our approach provides more control over model training as it enables us to actively decide on the trade-off between focusing on common or rare cases through a single hyperparameter, allowing the training of better models for rare data points.}, author = {Steininger, Michael and Kobs, Konstantin and Davidson, Padraig and Krause, Anna and Hotho, Andreas}, editor = {Appice, Annalisa and Escalera, Sergio and Gamez, Jose A. and Trautmann, Heike}, journal = {Machine Learning}, keywords = {2021 data density imbalanced myown regression}, title = {Density-based weighting for imbalanced regression}, year = 2021 }
43.
Wehner, N., Seufert, M., Schüler, J., Casas, P., Hoßfeld, T.: How are your Apps Doing? QoE Inference and Analysis in Mobile Devices. 17th International Conference on Network and Service Management (CNSM). , Izmir, Turkey (Virtual Conference) (2021).
[ Abstract ] [ BibTeX ]
 
Web browsing has become the most important application of the Internet for the end user. When it comes to mobile devices, web services are mainly accessed through apps. This paper tackles the problem of Web Quality of Experience (QoE) in mobile devices, with a specific focus on apps QoE monitoring and analysis, using in-network (encrypted) traffic measurements. Measuring apps QoE is complex, not only from an instrumentation point of view, but also from the heterogeneity of user interactions which might realize substantially different user experience. To this end, we conduct a feasibility study on four specific and popular Android apps and their corresponding web services. Our test automation framework emulates and measures different user interactions commonly executed during an app session, including the app startup, clicking, scrolling, and searching. The resulting traffic is characterized on different dimensions, and machine learning models are trained to identify web services, apps, and user interactions, and to infer their QoE. The proposed models can correctly identify the specific web service and app in 86% of the cases and accurately estimate the associated QoE with small errors. Our preliminary study represents a first step towards an in-network, web QoE monitoring solution for mobile-device apps.
@inproceedings{info3-inproceedings-2021-15, abstract = {Web browsing has become the most important application of the Internet for the end user. When it comes to mobile devices, web services are mainly accessed through apps. This paper tackles the problem of Web Quality of Experience (QoE) in mobile devices, with a specific focus on apps QoE monitoring and analysis, using in-network (encrypted) traffic measurements. Measuring apps QoE is complex, not only from an instrumentation point of view, but also from the heterogeneity of user interactions which might realize substantially different user experience. To this end, we conduct a feasibility study on four specific and popular Android apps and their corresponding web services. Our test automation framework emulates and measures different user interactions commonly executed during an app session, including the app startup, clicking, scrolling, and searching. The resulting traffic is characterized on different dimensions, and machine learning models are trained to identify web services, apps, and user interactions, and to infer their QoE. The proposed models can correctly identify the specific web service and app in 86% of the cases and accurately estimate the associated QoE with small errors. Our preliminary study represents a first step towards an in-network, web QoE monitoring solution for mobile-device apps.}, address = {Izmir, Turkey (Virtual Conference)}, author = {Wehner, Nikolas and Seufert, Michael and Schüler, Joshua and Casas, Pedro and Hoßfeld, Tobias}, booktitle = {17th International Conference on Network and Service Management (CNSM)}, keywords = {myown ucn}, month = 10, title = {How are your Apps Doing? QoE Inference and Analysis in Mobile Devices}, year = 2021 }
44.
Frank, F., Kaufmann, M., Kobourov, S., Mchedlidze, T., Pupyrev, S., Ueckerdt, T., Wolff, A.: Using the Metro-Map Metaphor for Drawing Hypergraphs. In: Burevs, T., Dondi, R., Gamper, J., Guerrini, G., Jurdziński, T., Pahl, C., Sikora, F., und Wong, P. (hrsg.) Proc. 47th Int. Conf. Current Trends Theory & Practice Comput. Sci. (SOFSEM’21). S. 361–372. Springer-Verlag (2021).
[ BibTeX ] [ DOI ]
 
@inproceedings{fkkmpuw-ummmdh-SOFSEM21, author = {Frank, Fabian and Kaufmann, Michael and Kobourov, Stephen and Mchedlidze, Tamara and Pupyrev, Sergey and Ueckerdt, Torsten and Wolff, Alexander}, booktitle = {Proc. 47th Int. Conf. Current Trends Theory \& Practice Comput. Sci. (SOFSEM'21)}, editor = {Bure\v{s}, Tom{á}\v{s} and Dondi, Riccardo and Gamper, Johann and Guerrini, Giovanna and Jurdzi{ń}ski, Tomasz and Pahl, Claus and Sikora, Florian and Wong, Prudence}, keywords = {myown}, pages = {361–372}, publisher = {Springer-Verlag}, series = {Lecture Notes in Computer Science}, title = {Using the Metro-Map Metaphor for Drawing Hypergraphs}, volume = 12607, year = 2021 }
45.
Walter, J., Zink, J., Baumeister, J., Wolff, A.: Layered Drawing of Undirected Graphs with Generalized Port Constraints. In: Auber, D. und Valtr, P. (hrsg.) Proc. 28th Int. Symp. Graph Drawing & Network Vis. (GD’20). S. 220–234. Springer-Verlag (2021).
[ BibTeX ] [ DOI ]
 
@inproceedings{wzbw-ldugg-GD20, author = {Walter, Julian and Zink, Johannes and Baumeister, Joachim and Wolff, Alexander}, booktitle = {Proc. 28th Int. Symp. Graph Drawing \& Network Vis. (GD'20)}, editor = {Auber, David and Valtr, Pavel}, keywords = {myown}, pages = {220–234}, publisher = {Springer-Verlag}, series = {Lecture Notes in Computer Science}, title = {Layered Drawing of Undirected Graphs with Generalized Port Constraints}, volume = 12590, year = 2021 }
46.
Güder, G., Wilkesmann, J., Scholz, N., Leppich, R., Düking, P., Sperlich, B., Rost, C., Frantz, S., Morbach, C., Sahiti, F., others: Establishing a cardiac training group for patients with heart failure: the “HIP-in-Würzburg” study. Clinical Research in Cardiology. 1–10 (2021).
[ BibTeX ]
 
@article{guder2021establishing, author = {G{ü}der, G{ü}lmisal and Wilkesmann, Joana and Scholz, Nina and Leppich, Robert and D{ü}king, Peter and Sperlich, Billy and Rost, Christian and Frantz, Stefan and Morbach, Caroline and Sahiti, Floran and others}, journal = {Clinical Research in Cardiology}, keywords = {descartes medicine t_journalmagazine myown}, pages = {1–10}, publisher = {Springer}, title = {Establishing a cardiac training group for patients with heart failure: the “HIP-in-W{ü}rzburg” study}, year = 2021 }
47.
Evans, W., Gethner, E., Spalding-Jamieson, J., Wolff, A.: Angle Covers: Algorithms and Complexity. Journal of Graph Algorithms & Applications. 25, 643–661 (2021).
[ BibTeX ] [ DOI ]
 
@article{egsw-acac-JGAA21, author = {Evans, William and Gethner, Ellen and Spalding-Jamieson, Jack and Wolff, Alexander}, journal = {Journal of Graph Algorithms \& Applications}, keywords = {myown}, number = 2, pages = {643–661}, title = {Angle Covers: Algorithms and Complexity}, volume = 25, year = 2021 }
48.
Obremski, D., Schäfer, A.L., Lange, B.P., Lugrin, B., Ganal, E., Witt, L., Nu~nez, T.R., Schwarz, S., Schwab, F.: Put that Away and Talk to Me - the Effects of Smartphone induced Ostracism while Interacting with an Intelligent Virtual Agent. Proceedings of the 9th International Conference on Human-Agent Interaction 2021. ACM (2021).
[ BibTeX ] [ DOI ]
 
@inproceedings{Obremski_2021, author = {Obremski, David and Schäfer, Alicia L. and Lange, Benjamin P. and Lugrin, Birgit and Ganal, Elisabeth and Witt, Laura and Nu{\ {n}}ez, Tania R. and Schwarz, Sascha and Schwab, Frank}, booktitle = {Proceedings of the 9th International Conference on Human-Agent Interaction 2021}, keywords = {birgit ganal mi myown obremski}, publisher = {ACM}, title = {Put that Away and Talk to Me - the Effects of Smartphone induced Ostracism while Interacting with an Intelligent Virtual Agent}, year = 2021 }
49.
Ripka, G., Grafe, S., Latoschik, M.E.: Mapping pre-service teachers’ TPACK development using a social virtual reality and a video-conferencing system. In: Bastiaens, T. (hrsg.) Proceedings of Innovate Learning Summit 2021. S. 145–159. Association for the Advancement of Computing in Education (AACE) (2021).
[ Abstract ] [ BibTeX ] [ URL ]
 
Social VR's characteristics, by offering authentic learning environments that enable interaction remotely and synchronously and permit learning experiences that affect learners in a multi-sensory way, offer great potential for teaching and learning processes. However, concerning its use to promote pre-service teachers' TPACK in initial teacher education, there remains a research desideratum. In this context, this exploratory study addressed the following research question: How did pre-service teachers' TPACK develop using a social VR learning environment prototype in comparison to a video conferencing platform throughout a semester? Following a design-based research approach, an action-oriented pedagogical concept for teaching and learning in social VR was designed and implemented for initial teacher education at a German university with a convenience sample of 14 participants. The lesson plans were collected and analyzed with the help of Epistemic Network Analysis (Shaffer, 2017) at three points of time during the semester and the GATI reflection process (Krauskopf et al., 2018). Further, 14 GATI diagrams gave insights into pre-service teachers' self-estimated TPACK. As the results indicate, pre-service students constructed more complex mental models of TPACK in social VR compared to the video conferencing platform, indicating that more interrelations between knowledge domains could be constructed by planning and designing VR-integrated lesson plans.
@inproceedings{gabrielaripka, abstract = {Social VR's characteristics, by offering authentic learning environments that enable interaction remotely and synchronously and permit learning experiences that affect learners in a multi-sensory way, offer great potential for teaching and learning processes. However, concerning its use to promote pre-service teachers' TPACK in initial teacher education, there remains a research desideratum. In this context, this exploratory study addressed the following research question: How did pre-service teachers' TPACK develop using a social VR learning environment prototype in comparison to a video conferencing platform throughout a semester? Following a design-based research approach, an action-oriented pedagogical concept for teaching and learning in social VR was designed and implemented for initial teacher education at a German university with a convenience sample of 14 participants. The lesson plans were collected and analyzed with the help of Epistemic Network Analysis (Shaffer, 2017) at three points of time during the semester and the GATI reflection process (Krauskopf et al., 2018). Further, 14 GATI diagrams gave insights into pre-service teachers' self-estimated TPACK. As the results indicate, pre-service students constructed more complex mental models of TPACK in social VR compared to the video conferencing platform, indicating that more interrelations between knowledge domains could be constructed by planning and designing VR-integrated lesson plans.}, author = {Ripka, Gabriela and Grafe, Silke and Latoschik, Marc Erich}, booktitle = {Proceedings of Innovate Learning Summit 2021}, editor = {Bastiaens, T.}, keywords = {myown}, organization = {Association for the Advancement of Computing in Education (AACE)}, pages = {145-159}, title = {Mapping pre-service teachers' TPACK development using a social virtual reality and a video-conferencing system}, year = 2021 }
50.
Chaplick, S., Kindermann, P., Klawitter, J., Rutter, I., Wolff, A.: Extending Partial Representations of Rectangular Duals with Given Contact Orientations. In: Calamoneri, T. und Coró, F. (hrsg.) Proc. 12th International Conference on Algorithms and Complexity (CIAC’21). S. 340–353. Springer-Verlag (2021).
[ BibTeX ] [ DOI ]
 
@inproceedings{ckkrw-eprrd-CIAC21, author = {Chaplick, Steven and Kindermann, Philipp and Klawitter, Jonathan and Rutter, Ignaz and Wolff, Alexander}, booktitle = {Proc. 12th International Conference on Algorithms and Complexity (CIAC'21)}, editor = {Calamoneri, Tiziana and Cor{ó}, Federico}, keywords = {myown}, pages = {340–353}, publisher = {Springer-Verlag}, series = {Lecture Notes in Computer Science}, title = {Extending Partial Representations of Rectangular Duals with Given Contact Orientations}, volume = 12701, year = 2021 }
51.
Arseneva, E., Kleist, L., Klemz, B., Löffler, M., Schulz, A., Vogtenhuber, B., Wolff, A.: Adjacency Graphs of Polyhedral Surfaces. In: Buchin, K. und Éric Colin de Verdière (hrsg.) Proc. 37th Annu. Sympos. Comput. Geom. (SoCG’21). S. 11:1–11:17. Schloss Dagstuhl~-- Leibniz-Zentrum für Informatik (2021).
[ BibTeX ] [ DOI ]
 
@inproceedings{akklsvw-dgps-SoCG21, author = {Arseneva, Elena and Kleist, Linda and Klemz, Boris and L{ö}ffler, Maarten and Schulz, Andr{é} and Vogtenhuber, Birgit and Wolff, Alexander}, booktitle = {Proc. 37th Annu. Sympos. Comput. Geom. (SoCG'21)}, editor = {Buchin, Kevin and {É}ric {Colin de Verdi{è}re}}, keywords = {contact_representation mykeypub myown polyhedral_complexes realizability}, pages = {11:1–11:17}, publisher = {Schloss Dagstuhl – Leibniz-Zentrum f{ü}r Informatik}, series = {LIPIcs}, title = {Adjacency Graphs of Polyhedral Surfaces}, volume = 189, year = 2021 }
52.
Geiger, J., Cornelsen, S., Haunert, J.-H., Kindermann, P., Mchedlidze, T., Nöllenburg, M., Okamoto, Y., Wolff, A.: ClusterSets: Optimizing Planar Clusters in Categorical Point Data. Comput. Graphics Forum. 40, 471–481 (2021).
[ BibTeX ] [ DOI ]
 
@article{gchkmnow-coplc-EuroVis21, author = {Geiger, Jakob and Cornelsen, Sabine and Haunert, Jan-Henrik and Kindermann, Philipp and Mchedlidze, Tamara and N{ö}llenburg, Martin and Okamoto, Yoshio and Wolff, Alexander}, journal = {Comput. Graphics Forum}, keywords = {myown}, number = 3, pages = {471–481}, title = {ClusterSets: Optimizing Planar Clusters in Categorical Point Data}, volume = 40, year = 2021 }
53.
Halbig, A., Latoschik, M.E.: A Systematic Review of Physiological Measurements, Factors, Methods, and Applications in Virtual Reality. Frontiers in Virtual Reality. 2, 89 (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Measurements of physiological parameters provide an objective, often non-intrusive, and (at least semi-)automatic evaluation and utilization of user behavior. In addition, specific hardware devices of Virtual Reality (VR) often ship with built-in sensors, i.e. eye-tracking and movements sensors. Hence, the combination of physiological measurements and VR applications seems promising. Several approaches have investigated the applicability and benefits of this combination for various fields of applications. However, the range of possible application fields, coupled with potentially useful and beneficial physiological parameters, types of sensor, target variables and factors, and analysis approaches and techniques is manifold. This article provides a systematic overview and an extensive state-of-the-art review of the usage of physiological measurements in VR. We identified 1,119 works that make use of physiological measurements in VR. Within these, we identified 32 approaches that focus on the classification of characteristics of experience, common in VR applications. The first part of this review categorizes the 1,119 works by field of application, i.e. therapy, training, entertainment, and communication and interaction, as well as by the specific target factors and variables measured by the physiological parameters. An additional category summarizes general VR approaches applicable to all specific fields of application since they target typical VR qualities. In the second part of this review, we analyze the target factors and variables regarding the respective methods used for an automatic analysis and, potentially, classification. For example, we highlight which measurement setups have been proven to be sensitive enough to distinguish different levels of arousal, valence, anxiety, stress, or cognitive workload in the virtual realm. This work may prove useful for all researchers wanting to use physiological data in VR and who want to have a good overview of prior approaches taken, their benefits and potential drawbacks.
@article{10.3389/frvir.2021.694567, abstract = {Measurements of physiological parameters provide an objective, often non-intrusive, and (at least semi-)automatic evaluation and utilization of user behavior. In addition, specific hardware devices of Virtual Reality (VR) often ship with built-in sensors, i.e. eye-tracking and movements sensors. Hence, the combination of physiological measurements and VR applications seems promising. Several approaches have investigated the applicability and benefits of this combination for various fields of applications. However, the range of possible application fields, coupled with potentially useful and beneficial physiological parameters, types of sensor, target variables and factors, and analysis approaches and techniques is manifold. This article provides a systematic overview and an extensive state-of-the-art review of the usage of physiological measurements in VR. We identified 1,119 works that make use of physiological measurements in VR. Within these, we identified 32 approaches that focus on the classification of characteristics of experience, common in VR applications. The first part of this review categorizes the 1,119 works by field of application, i.e. therapy, training, entertainment, and communication and interaction, as well as by the specific target factors and variables measured by the physiological parameters. An additional category summarizes general VR approaches applicable to all specific fields of application since they target typical VR qualities. In the second part of this review, we analyze the target factors and variables regarding the respective methods used for an automatic analysis and, potentially, classification. For example, we highlight which measurement setups have been proven to be sensitive enough to distinguish different levels of arousal, valence, anxiety, stress, or cognitive workload in the virtual realm. This work may prove useful for all researchers wanting to use physiological data in VR and who want to have a good overview of prior approaches taken, their benefits and potential drawbacks.}, author = {Halbig, Andreas and Latoschik, Marc Erich}, journal = {Frontiers in Virtual Reality}, keywords = {hci-uwb myown via-vr}, pages = 89, title = {A Systematic Review of Physiological Measurements, Factors, Methods, and Applications in Virtual Reality}, volume = 2, year = 2021 }
54.
Oberdörfer, S., Birnstiel, S., Latoschik, M.E., Grafe, S.: Mutual Benefits: Interdisciplinary Education of Pre-Service Teachers and HCI Students in VR/AR Learning Environment Design. Frontiers in Education. 6, 233 (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@article{oberdorfer2021mutual, author = {Oberdörfer, Sebastian and Birnstiel, Sandra and Latoschik, Marc Erich and Grafe, Silke}, journal = {Frontiers in Education}, keywords = {myown oberdoerfer varyfast}, pages = 233, title = {Mutual Benefits: Interdisciplinary Education of Pre-Service Teachers and HCI Students in VR/AR Learning Environment Design}, volume = 6, year = 2021 }
55.
Münster, S., Maiwald, F., Bruschke, J., Kröber, C., Dietz, R., Messemer, H., Niebling, F.: WHERE ARE WE NOW ON THE ROAD TO 4D URBAN HISTORY RESEARCH AND DISCOVERY?. ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences. VIII-M-1-2021, 109–116 (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@article{isprs-annals-VIII-M-1-2021-109-2021, author = {Münster, S. and Maiwald, F. and Bruschke, J. and Kröber, C. and Dietz, R. and Messemer, H. and Niebling, F.}, journal = {ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences}, keywords = {histstadt4d myown niebling}, pages = {109–116}, title = {WHERE ARE WE NOW ON THE ROAD TO 4D URBAN HISTORY RESEARCH AND DISCOVERY?}, volume = {VIII-M-1-2021}, year = 2021 }
56.
Hoßfeld, T., Seufert, M., Naderi, B.: On Inter-Rater Reliability for Crowdsourced QoE. 13th International Conference on Quality of Multimedia Experience (QoMEX). , Montreal, Canada (Virtual Conference) (2021).
[ BibTeX ]
 
@inproceedings{info3-inproceedings-2021-9, address = {Montreal, Canada (Virtual Conference)}, author = {Hoßfeld, Tobias and Seufert, Michael and Naderi, Babak}, booktitle = {13th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {myown ucn}, month = 6, title = {On Inter-Rater Reliability for Crowdsourced QoE}, year = 2021 }
57.
Eismann, S., Scheuner, J., van Eyk, E., Schwinger, M., Grohmann, J., Herbst, N., Abad, C., Iosup, A.: The State of Serverless Applications: Collection, Characterization, and Community Consensus. Transactions on Software Engineering. (2021).
[ Abstract ] [ BibTeX ] [ URL ]
 
Over the last five years, all major cloud platform providers have increased their serverless offerings. Many early adopters report significant benefits for serverless-based over traditional applications, and many companies are considering moving to serverless themselves. However, currently there exist only few, scattered, and sometimes even conflicting reports on when serverless applications are well suited and what the best practices for their implementation are. We address this problem in the present study about the state of serverless applications. We collect descriptions of 89 serverless applications from open-source projects, academic literature, industrial literature, and domain-specific feedback. We analyze 16 characteristics that describe why and when successful adopters are using serverless applications, and how they are building them. We further compare the results of our characterization study to 10 existing, mostly industrial, studies and datasets; this allows us to identify points of consensus across multiple studies, investigate points of disagreement, and overall confirm the validity of our results. The results of this study can help managers to decide if they should adopt serverless technology, engineers to learn about current practices of building serverless applications, and researchers and platform providers to better understand the current landscape of serverless applications.
@article{eismann2021state, abstract = {Over the last five years, all major cloud platform providers have increased their serverless offerings. Many early adopters report significant benefits for serverless-based over traditional applications, and many companies are considering moving to serverless themselves. However, currently there exist only few, scattered, and sometimes even conflicting reports on when serverless applications are well suited and what the best practices for their implementation are. We address this problem in the present study about the state of serverless applications. We collect descriptions of 89 serverless applications from open-source projects, academic literature, industrial literature, and domain-specific feedback. We analyze 16 characteristics that describe why and when successful adopters are using serverless applications, and how they are building them. We further compare the results of our characterization study to 10 existing, mostly industrial, studies and datasets; this allows us to identify points of consensus across multiple studies, investigate points of disagreement, and overall confirm the validity of our results. The results of this study can help managers to decide if they should adopt serverless technology, engineers to learn about current practices of building serverless applications, and researchers and platform providers to better understand the current landscape of serverless applications.}, author = {Eismann, Simon and Scheuner, Joel and van Eyk, Erwin and Schwinger, Maximilian and Grohmann, Johannes and Herbst, Nikolas and Abad, Cristina and Iosup, Alexandru}, journal = {Transactions on Software Engineering}, keywords = {t_journalmagazine myown select descartes}, title = {The State of Serverless Applications: Collection, Characterization, and Community Consensus}, year = 2021 }
58.
Hein, R.M., Steinbock, J., Eisenmann, M., Wienrich, C., Latoschik, M.E.: Inter- und Transkulturelles Lernen in Virtual Reality - Ein Seminarkonzept für die Lehrkräfteausbildung im Fach Englisch. In: Söbke, H. & Weise, M. (Hrsg.), Wettbewerbsband AVRiL 2021. 34–39 (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Inter- und transkulturelle Kompetenzen sind zentrale Elemente einer aktiven Teilhabe in einer modernen Gesellschaft. Die Fremdsprachenforschung setzt sich im Kontext der Digitalisierung mit neuen Konzepten zum Erwerb dieser Kompetenzen im Fremdsprachenunterricht auseinander. Eine Zusammenarbeit mit der HCI-Forschung zum Einsatz von social VR im Klassenzimmer lässt auf einen positiven Erkenntnisgewinn schließen. So lautet die zentrale Forschungshypothese, dass vollimmersive Lernumgebungen verstärkt inter- und transkulturelle Lernprozesse fördern, weil Lernende VR-Welten nicht nur betrachten, sondern innerhalb dieser selbstwirksam interagieren und das Umfeld eigenständig manipulieren können. Darauf aufbauend wurde ein Seminarkonzept entwickelt, in dem Lehramtsstudierende für das Fach Englisch inter- und transkulturelle Lehr/Lernszenarien in VR konzipieren, die sie dann in ihrer Unterrichtspraxis einsetzen können. So lernen Studierende das Potenzial von VR nicht nur kennen, sondern ebenso dieses unterrichtlich umzusetzen.
@article{hein2021inter, abstract = {Inter- und transkulturelle Kompetenzen sind zentrale Elemente einer aktiven Teilhabe in einer modernen Gesellschaft. Die Fremdsprachenforschung setzt sich im Kontext der Digitalisierung mit neuen Konzepten zum Erwerb dieser Kompetenzen im Fremdsprachenunterricht auseinander. Eine Zusammenarbeit mit der HCI-Forschung zum Einsatz von social VR im Klassenzimmer lässt auf einen positiven Erkenntnisgewinn schließen. So lautet die zentrale Forschungshypothese, dass vollimmersive Lernumgebungen verstärkt inter- und transkulturelle Lernprozesse fördern, weil Lernende VR-Welten nicht nur betrachten, sondern innerhalb dieser selbstwirksam interagieren und das Umfeld eigenständig manipulieren können. Darauf aufbauend wurde ein Seminarkonzept entwickelt, in dem Lehramtsstudierende für das Fach Englisch inter- und transkulturelle Lehr/Lernszenarien in VR konzipieren, die sie dann in ihrer Unterrichtspraxis einsetzen können. So lernen Studierende das Potenzial von VR nicht nur kennen, sondern ebenso dieses unterrichtlich umzusetzen.}, author = {Hein, Rebecca M and Steinbock, Jeanine and Eisenmann, Maria and Wienrich, Carolin and Latoschik, Marc Erich}, journal = {In: Söbke, H. & Weise, M. (Hrsg.), Wettbewerbsband AVRiL 2021}, keywords = {Rhein c.wienrich hci-uwb myown rebeccahein rhein}, pages = {34-39}, title = {Inter- und Transkulturelles Lernen in Virtual Reality - Ein Seminarkonzept für die Lehrkräfteausbildung im Fach Englisch}, year = 2021 }
59.
Gall, D., Roth, D., Stauffert, J.-P., Zarges, J., Latoschik, M.E.: Virtual Body Ownership Intensifies Emotional Responses to Virtual Stimuli. Frontiers in Psychology - Cognitive Science. 12, 3833 (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
Modulating emotional responses to virtual stimuli is a fundamental goal of many immersive interactive applications. In this study, we leverage the illusion of illusory embodiment and show that owning a virtual body provides means to modulate emotional responses. In a single-factor repeated-measures experiment, we manipulated the degree of illusory embodiment and assessed the emotional responses to virtual stimuli. We presented emotional stimuli in the same environment as the virtual body. Participants experienced higher arousal, dominance, and more intense valence in the high embodiment condition compared to the low embodiment condition. The illusion of embodiment thus intensifies the emotional processing of the virtual environment. This result suggests that artificial bodies can increase the effectiveness of immersive applications psychotherapy, entertainment, computer-mediated social interactions, or health applications.
@article{gall2021virtual, abstract = {Modulating emotional responses to virtual stimuli is a fundamental goal of many immersive interactive applications. In this study, we leverage the illusion of illusory embodiment and show that owning a virtual body provides means to modulate emotional responses. In a single-factor repeated-measures experiment, we manipulated the degree of illusory embodiment and assessed the emotional responses to virtual stimuli. We presented emotional stimuli in the same environment as the virtual body. Participants experienced higher arousal, dominance, and more intense valence in the high embodiment condition compared to the low embodiment condition. The illusion of embodiment thus intensifies the emotional processing of the virtual environment. This result suggests that artificial bodies can increase the effectiveness of immersive applications psychotherapy, entertainment, computer-mediated social interactions, or health applications.}, author = {Gall, Dominik and Roth, Daniel and Stauffert, Jan-Philipp and Zarges, Julian and Latoschik, Marc Erich}, editor = {DiPaola, Steve Richard and Bernardet, Ulysses and Gratch, Jonathan}, journal = {Frontiers in Psychology - Cognitive Science}, keywords = {myown}, pages = 3833, title = {Virtual Body Ownership Intensifies Emotional Responses to Virtual Stimuli}, volume = 12, year = 2021 }
60.
Metzger, F., Rafetseder, A., Schröder, S., Zwickl, P.: The Prospects of Cloud Gaming: Do the Benefits Outweigh the Costs?, (2021).
[ BibTeX ]
 
@misc{info3-misc-2021-2, author = {Metzger, Florian and Rafetseder, Albert and Schröder, Svenja and Zwickl, Patrick}, howpublished = {https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-242452}, keywords = {myown}, month = 8, title = {The Prospects of Cloud Gaming: Do the Benefits Outweigh the Costs?}, year = 2021 }
61.
Gray, N., Dietz, K., Seufert, M., Hoßfeld, T.: High Performance Network Metadata Extraction Using P4 for ML-Based Intrusion Detection Systems. 22nd International Conference on High Performance Switching and Routing (HPSR). , Paris, France (Virtual Conference) (2021).
[ BibTeX ]
 
@inproceedings{info3-inproceedings-2021-8, address = {Paris, France (Virtual Conference)}, author = {Gray, Nicholas and Dietz, Katharina and Seufert, Michael and Hoßfeld, Tobias}, booktitle = {22nd International Conference on High Performance Switching and Routing (HPSR)}, keywords = {myown wintermute ucn}, month = 6, title = {High Performance Network Metadata Extraction Using P4 for ML-Based Intrusion Detection Systems}, year = 2021 }
62.
Oberdörfer, S., Elsässer, A., Grafe, S., Latoschik, M.E.: Grab the Frog: Comparing Intuitive Use and User Experience of a Smartphone-only, AR-only, and Tangible AR Learning Environment. Proceedings of the 23rd International Conference on Mobile Human-Computer Interaction (MobileHCI ’21). (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@article{oberdorfer2021comparing, author = {Oberdörfer, Sebastian and Elsässer, Anne and Grafe, Silke and Latoschik, Marc Erich}, journal = {Proceedings of the 23rd International Conference on Mobile Human-Computer Interaction (MobileHCI '21)}, keywords = {horst leed myown oberdoerfer}, month = {September}, title = {Grab the Frog: Comparing Intuitive Use and User Experience of a Smartphone-only, AR-only, and Tangible AR Learning Environment}, year = 2021 }
63.
Orsolic, I., Seufert, M.: On Machine Learning based Video QoE Estimation Across Different Networks. 16th International Conference on Telecommunications (ConTEL), Best Paper Award. , Zagreb, Croatia (Virtual Conference) (2021).
[ BibTeX ]
 
@inproceedings{info3-inproceedings-2021-10, address = {Zagreb, Croatia (Virtual Conference)}, author = {Orsolic, Irena and Seufert, Michael}, booktitle = {16th International Conference on Telecommunications (ConTEL), Best Paper Award}, keywords = {myown ucn}, month = 7, title = {On Machine Learning based Video QoE Estimation Across Different Networks}, year = 2021 }
64.
Metzger, F., Schröder, S., Ratetseder, A.: Subjective And Objective Assessment Of Video Game Context Factors, (2021).
[ BibTeX ]
 
@misc{info3-misc-2021-1, author = {Metzger, Florian and Schröder, Svenja and Ratetseder, Albert}, howpublished = {https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-242471}, keywords = {myown}, month = 8, title = {Subjective And Objective Assessment Of Video Game Context Factors}, year = 2021 }
65.
Glémarec, Y., Lugrin, J.-L., Bosser, A.-G., Collins Jackson, A., Buche, C., Latoschik, M.E.: Indifferent or Enthusiastic? Virtual Audiences Animation and Perception in Virtual Reality. Frontiers in Virtual Reality. 2, 72 (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
In this paper, we present a virtual audience simulation system for Virtual Reality (VR). The system implements an audience perception model controlling the nonverbal behaviors of virtual spectators, such as facial expressions or postures. Groups of virtual spectators are animated by a set of nonverbal behavior rules representing a particular audience attitude (e.g., indifferent or enthusiastic). Each rule specifies a nonverbal behavior category: posture, head movement, facial expression and gaze direction as well as three parameters: type, frequency and proportion. In a first user-study, we asked participants to pretend to be a speaker in VR and then create sets of nonverbal behaviour parameters to simulate different attitudes. Participants manipulated the nonverbal behaviours of single virtual spectator to match a specific levels of engagement and opinion toward them. In a second user-study, we used these parameters to design different types of virtual audiences with our nonverbal behavior rules and evaluated their perceptions. Our results demonstrate our system’s ability to create virtual audiences with three types of different perceived attitudes: indifferent, critical, enthusiastic. The analysis of the results also lead to a set of recommendations and guidelines regarding attitudes and expressions for future design of audiences for VR therapy and training applications.
@article{10.3389/frvir.2021.666232, abstract = {In this paper, we present a virtual audience simulation system for Virtual Reality (VR). The system implements an audience perception model controlling the nonverbal behaviors of virtual spectators, such as facial expressions or postures. Groups of virtual spectators are animated by a set of nonverbal behavior rules representing a particular audience attitude (e.g., indifferent or enthusiastic). Each rule specifies a nonverbal behavior category: posture, head movement, facial expression and gaze direction as well as three parameters: type, frequency and proportion. In a first user-study, we asked participants to pretend to be a speaker in VR and then create sets of nonverbal behaviour parameters to simulate different attitudes. Participants manipulated the nonverbal behaviours of single virtual spectator to match a specific levels of engagement and opinion toward them. In a second user-study, we used these parameters to design different types of virtual audiences with our nonverbal behavior rules and evaluated their perceptions. Our results demonstrate our system’s ability to create virtual audiences with three types of different perceived attitudes: indifferent, critical, enthusiastic. The analysis of the results also lead to a set of recommendations and guidelines regarding attitudes and expressions for future design of audiences for VR therapy and training applications.}, author = {Glémarec, Yann and Lugrin, Jean-Luc and Bosser, Anne-Gwenn and Collins Jackson, Aryana and Buche, Cédric and Latoschik, Marc Erich}, journal = {Frontiers in Virtual Reality}, keywords = {lugrin myown vraudi}, pages = 72, title = {Indifferent or Enthusiastic? Virtual Audiences Animation and Perception in Virtual Reality}, volume = 2, year = 2021 }
66.
Seufert, A., Wamser, F., Wunderer, S., Hall, A., Hoßfeld, T.: Trust but Verify: Crowdsourced Mobile Network Measurements and Statistical Validity Measures. 2021 Joint European Conference on Networks and Communications & 6G Summit (EuCNC/6G Summit). , Porto, Portugal (virtual conference) (2021).
[ Abstract ] [ BibTeX ]
 
Network operators, regulators, and big data companies use crowdsourced measurements to study the performance of mobile networks on a large scale. Such a type of measurement is defined as the collection and processing of data measured by the crowd, here the crowd of mobile subscribers. Crowdsourced network measurements make it relatively easy and inexpensive to obtain large amounts of network data that also reflect the quality actually received by the end user. However, this measurement method also involves some uncertainties, since, for example, it is not possible to precisely control when, where and with which devices measurements are taken. Thus, there is a trade-off between the reliability of the individual measurement and the scope of the measurements. Therefore, how data of this type is analyzed is particularly important in order to obtain valid results. To address this issue, our paper defines concepts and guidelines for analyzing the validity of crowdsourced mobile network measurements. In particular, we address precision, for example the number of measurements needed to make valid statements, and also representativeness, for example the spatial and temporal distribution of the data. In addition to the formal definition of these two aspects, we illustrate the issue and possible evaluation approaches with the help of an extensive example data set. This data set consists of more than 11.7M crowdsourced mobile measurements from all over France, measured by a commercial mobile data provider. In the end, we provide an evaluation guideline and two possible use cases.
@inproceedings{info3-inproceedings-2021-11, abstract = {Network operators, regulators, and big data companies use crowdsourced measurements to study the performance of mobile networks on a large scale. Such a type of measurement is defined as the collection and processing of data measured by the crowd, here the crowd of mobile subscribers. Crowdsourced network measurements make it relatively easy and inexpensive to obtain large amounts of network data that also reflect the quality actually received by the end user. However, this measurement method also involves some uncertainties, since, for example, it is not possible to precisely control when, where and with which devices measurements are taken. Thus, there is a trade-off between the reliability of the individual measurement and the scope of the measurements. Therefore, how data of this type is analyzed is particularly important in order to obtain valid results. To address this issue, our paper defines concepts and guidelines for analyzing the validity of crowdsourced mobile network measurements. In particular, we address precision, for example the number of measurements needed to make valid statements, and also representativeness, for example the spatial and temporal distribution of the data. In addition to the formal definition of these two aspects, we illustrate the issue and possible evaluation approaches with the help of an extensive example data set. This data set consists of more than 11.7M crowdsourced mobile measurements from all over France, measured by a commercial mobile data provider. In the end, we provide an evaluation guideline and two possible use cases.}, address = {Porto, Portugal (virtual conference)}, author = {Seufert, Anika and Wamser, Florian and Wunderer, Stefan and Hall, Andrew and Hoßfeld, Tobias}, booktitle = {2021 Joint European Conference on Networks and Communications & 6G Summit (EuCNC/6G Summit)}, keywords = {myown 5gqmon can}, month = 6, title = {Trust but Verify: Crowdsourced Mobile Network Measurements and Statistical Validity Measures}, year = 2021 }
67.
Seufert, A., Wamser, F., Yarish, D., Macdonald, H., Hoßfeld, T.: QoE Models in the Wild: Comparing Video QoE Models Using a Crowdsourced Data Set. 2021 13th International Conference on Quality of Multimedia Experience (QoMEX). , Montreal, Canada (virtual conference) (2021).
[ Abstract ] [ BibTeX ]
 
Crowdsourced measurements solve the problem of being able to assess the performance of a communication network from an end-user perspective, but the new characteristics of the data pose new challenges for QoE modeling. In contrast to existing laboratory or network measurements, this type of measurement at the end-user device primarily involves taking a large number of short sample measurements, which, however, are rich in measured parameters, including many user-, application-, and device-related parameters. To test the applicability and to facilitate the integration of such data, we applied four QoE models from the literature to 290k worldwide video streaming measurements from a commercial data set from August to October 2020. In this work, we will therefore first describe the crowdsourcing video streaming data set to provide insights into the properties of video streaming KPIs in the real-world. Second, we run four popular QoE models using this data set, compare the resulting QoE scores, and derive the impact of individual KPIs for each model. We show that the models assess the QoE at least differently, but sometimes with contradicting statements. Reading this paper, it becomes evident that more work and subjective studies, based on real-world data like the one we have shown, are needed to extend the current QoE models.
@inproceedings{info3-inproceedings-2021-12, abstract = {Crowdsourced measurements solve the problem of being able to assess the performance of a communication network from an end-user perspective, but the new characteristics of the data pose new challenges for QoE modeling. In contrast to existing laboratory or network measurements, this type of measurement at the end-user device primarily involves taking a large number of short sample measurements, which, however, are rich in measured parameters, including many user-, application-, and device-related parameters. To test the applicability and to facilitate the integration of such data, we applied four QoE models from the literature to 290k worldwide video streaming measurements from a commercial data set from August to October 2020. In this work, we will therefore first describe the crowdsourcing video streaming data set to provide insights into the properties of video streaming KPIs in the real-world. Second, we run four popular QoE models using this data set, compare the resulting QoE scores, and derive the impact of individual KPIs for each model. We show that the models assess the QoE at least differently, but sometimes with contradicting statements. Reading this paper, it becomes evident that more work and subjective studies, based on real-world data like the one we have shown, are needed to extend the current QoE models.}, address = {Montreal, Canada (virtual conference)}, author = {Seufert, Anika and Wamser, Florian and Yarish, David and Macdonald, Hunter and Hoßfeld, Tobias}, booktitle = {2021 13th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {myown tutela-video can}, month = 6, title = {QoE Models in the Wild: Comparing Video QoE Models Using a Crowdsourced Data Set}, year = 2021 }
68.
Nguyen Huu, T., Trung Kien, N., Van Hoa, N., Thu Huong, T., Wamser, F., Hoßfeld, T.: Energy-Aware Service Function Chain Embedding in Edge-Cloud Environments for IoT Applications. IEEE Internet of Things Journal. (2021).
[ Abstract ] [ BibTeX ]
 
The implementation of IoT applications faces several challenges in practice, such as compliance with QoS requirements, resource constraints and energy consumption. In this context, the joint paradigm for IoT applications can resolve some of the issues arising in pure cloud computing scenarios, such as those related to latency, energy or privacy. Therefore, an environment could be promising for resource and energy-efficient IoT applications that implement VNF bound together into SFC. However, a resource and energy efficient SFC placement requires smart SFC embedding mechanisms in the environment, as several challenges arise, such as IoT service chain modeling and evaluation, the trade-off between resource allocation, energy efficiency and performance, and the resource dynamics. In this article, we address issues in modeling resource and energy utilization for IoT applications in environments. A smart traffic monitoring IP camera system is deployed as a use case for a realistic modeling of a service chain. The system is implemented in our testbed, which is designed and developed specifically to model and investigate the resource and energy utilization of SFC embedding strategies. A resource and energy-aware SFC strategy in the environment for IoT applications is then proposed. Our algorithm is able to cope with dynamic load and resource situations emerging from dynamic SFC requests. The strategy is evaluated systematically in terms of acceptance ratio of SFC requests, resource efficiency and utilization, power consumption, and VNF migrations depending on the offered system load. Results show that our strategy outperforms some existing approaches in terms of resource and energy efficiency, thus it overcomes the relevant challenges from practice and meets the demands of IoT applications.
@article{info3-article-2021-2, abstract = {The implementation of IoT applications faces several challenges in practice, such as compliance with QoS requirements, resource constraints and energy consumption. In this context, the joint paradigm for IoT applications can resolve some of the issues arising in pure cloud computing scenarios, such as those related to latency, energy or privacy. Therefore, an environment could be promising for resource and energy-efficient IoT applications that implement VNF bound together into SFC. However, a resource and energy efficient SFC placement requires smart SFC embedding mechanisms in the environment, as several challenges arise, such as IoT service chain modeling and evaluation, the trade-off between resource allocation, energy efficiency and performance, and the resource dynamics. In this article, we address issues in modeling resource and energy utilization for IoT applications in environments. A smart traffic monitoring IP camera system is deployed as a use case for a realistic modeling of a service chain. The system is implemented in our testbed, which is designed and developed specifically to model and investigate the resource and energy utilization of SFC embedding strategies. A resource and energy-aware SFC strategy in the environment for IoT applications is then proposed. Our algorithm is able to cope with dynamic load and resource situations emerging from dynamic SFC requests. The strategy is evaluated systematically in terms of acceptance ratio of SFC requests, resource efficiency and utilization, power consumption, and VNF migrations depending on the offered system load. Results show that our strategy outperforms some existing approaches in terms of resource and energy efficiency, thus it overcomes the relevant challenges from practice and meets the demands of IoT applications.}, author = {Nguyen Huu, Thanh and Trung Kien, Nguyen and Van Hoa, Ngo and Thu Huong, Truong and Wamser, Florian and Hoßfeld, Tobias}, journal = {IEEE Internet of Things Journal}, keywords = {myown ecodane}, month = 3, title = {Energy-Aware Service Function Chain Embedding in Edge-Cloud Environments for IoT Applications}, year = 2021 }
69.
Grohmann, J., Eismann, S., Bauer, A., Spinner, S., Blum, J., Herbst, N., Kounev, S.: SARDE: A Framework for Continuous and Self-Adaptive Resource Demand Estimation. ACM Transactions on Autonomous and Adaptive Systems. 15, (2021).
[ Abstract ] [ BibTeX ] [ URL ]
 
Resource demands are crucial parameters for modeling and predicting the performance of software systems. Currently, resource demand estimators are usually executed once for system analysis. However, the monitored system, as well as the resource demand itself, are subject to constant change in runtime environments. These changes additionally impact the applicability, the required parametrization as well as the resulting accuracy of individual estimation approaches. Over time, this leads to invalid or outdated estimates, which in turn negatively influence the decision-making of adaptive systems. In this article, we present SARDE, a framework for self-adaptive resource demand estimation in continuous environments. SARDE dynamically and continuously tunes, selects, and executes an ensemble of resource demand estimation approaches to adapt to changes in the environment. This creates an autonomous and unsupervised ensemble estimation technique, providing reliable resource demand estimations in dynamic environments. We evaluate SARDE using two realistic datasets. One set of different micro-benchmarks reflecting different possible system states and one dataset consisting of a continuously running application in a changing environment. Our results show that by continuously applying online optimization, selection and estimation, SARDE is able to efficiently adapt to the online trace and reduce the model error using the resulting ensemble technique.
@article{GrEiBaSpBlHeKo2021-TaaS-SARDE, abstract = {Resource demands are crucial parameters for modeling and predicting the performance of software systems. Currently, resource demand estimators are usually executed once for system analysis. However, the monitored system, as well as the resource demand itself, are subject to constant change in runtime environments. These changes additionally impact the applicability, the required parametrization as well as the resulting accuracy of individual estimation approaches. Over time, this leads to invalid or outdated estimates, which in turn negatively influence the decision-making of adaptive systems. In this article, we present SARDE, a framework for self-adaptive resource demand estimation in continuous environments. SARDE dynamically and continuously tunes, selects, and executes an ensemble of resource demand estimation approaches to adapt to changes in the environment. This creates an autonomous and unsupervised ensemble estimation technique, providing reliable resource demand estimations in dynamic environments. We evaluate SARDE using two realistic datasets. One set of different micro-benchmarks reflecting different possible system states and one dataset consisting of a continuously running application in a changing environment. Our results show that by continuously applying online optimization, selection and estimation, SARDE is able to efficiently adapt to the online trace and reduce the model error using the resulting ensemble technique.}, address = {New York, NY, USA}, author = {Grohmann, Johannes and Eismann, Simon and Bauer, Andr{é} and Spinner, Simon and Blum, Johannes and Herbst, Nikolas and Kounev, Samuel}, journal = {ACM Transactions on Autonomous and Adaptive Systems}, keywords = {Self-adaptive algorithms demand descartes estimation learning machine optimization performance prediction resource self-tuning statistical_estimation_and_machine_learning systems t_journalmagazine myown}, month = {jun}, number = 2, publisher = {Association for Computing Machinery}, title = {SARDE: A Framework for Continuous and Self-Adaptive Resource Demand Estimation}, volume = 15, year = 2021 }
70.
Metzger, F., Stulier, N., Borchert, K., Hirth, M.: Relationship Status: It’s Complicated. Using APM as a QoE-qualifying Tempo Metric. Proceedings of the 13th International Conference on Quality of Multimedia Experience (QoMEX 2021) (2021).
[ BibTeX ]
 
@inproceedings{info3-inproceedings-2021-13, author = {Metzger, Florian and Stulier, Norman and Borchert, Kathrin and Hirth, Matthias}, booktitle = {Proceedings of the 13th International Conference on Quality of Multimedia Experience (QoMEX 2021)}, keywords = {myown}, month = 6, title = {Relationship Status: It's Complicated. Using APM as a QoE-qualifying Tempo Metric}, year = 2021 }
71.
Loh, F., Poignée, F., Wamser, F., Leidinger, F., Hoßfeld, T.: Uplink vs. Downlink: Machine Learning-Based Quality Prediction for HTTP Adaptive Video Streaming. Sensors. 21, 4172 (2021).
[ Abstract ] [ BibTeX ]
 
Streaming video is responsible for the bulk of Internet traffic these days. For this reason, Internet providers and network operators try to make predictions and assessments about the streaming quality for an end user. Current monitoring solutions are based on a variety of different machine learning approaches. The challenge for providers and operators nowadays is that existing approaches require large amounts of data. In this work, the most relevant quality of experience metrics, i.e., the initial playback delay, the video streaming quality, video quality changes, and video rebuffering events, are examined using a voluminous data set of more than 13,000 YouTube video streaming runs that were collected with the native YouTube mobile app. Three Machine Learning models are developed and compared to estimate playback behavior based on uplink request information. The main focus has been on developing a lightweight approach using as few features and as little data as possible, while maintaining state-of-the-art performance.
@article{info3-article-2021-3, abstract = {Streaming video is responsible for the bulk of Internet traffic these days. For this reason, Internet providers and network operators try to make predictions and assessments about the streaming quality for an end user. Current monitoring solutions are based on a variety of different machine learning approaches. The challenge for providers and operators nowadays is that existing approaches require large amounts of data. In this work, the most relevant quality of experience metrics, i.e., the initial playback delay, the video streaming quality, video quality changes, and video rebuffering events, are examined using a voluminous data set of more than 13,000 YouTube video streaming runs that were collected with the native YouTube mobile app. Three Machine Learning models are developed and compared to estimate playback behavior based on uplink request information. The main focus has been on developing a lightweight approach using as few features and as little data as possible, while maintaining state-of-the-art performance.}, author = {Loh, Frank and Poignée, Fabian and Wamser, Florian and Leidinger, Ferdinand and Hoßfeld, Tobias}, journal = {Sensors}, keywords = {myown youtube can}, number = 12, pages = 4172, title = {Uplink vs. Downlink: Machine Learning-Based Quality Prediction for HTTP Adaptive Video Streaming}, volume = 21, year = 2021 }
72.
Herrnleben, S., Grohmann, J., Rygielski, P., Lesch, V., Krupitzer, C., Kounev, S.: A Simulation-based Optimization Framework for Online Adaptation of Networks. In: Song, H. und Jiang, D. (hrsg.) Proceedings of the 12th EAI International Conference on Simulation Tools and Techniques (SIMUtools). S. 513–532. Springer International Publishing, Cham (2021).
[ Abstract ] [ BibTeX ] [ URL ]
 
Today's data centers face a rapid change of deployed services, growing complexity, and increasing performance requirements. Customers expect not only round-the-clock availability of the hosted services but also high responsiveness. Besides optimizing software architectures and deployments, networks have to be adapted to handle the changing and volatile demands. Approaches from self-adaptive systems can be used for optimizing data center networks to continuously meet Service Level Agreements (SLAs) between data center operators and customers. However, existing approaches focus only on specific objectives like topology design, power optimization, or traffic engineering. In this paper, we present an extensible framework that analyzes networks using different types of simulation and adapts them subject to multiple objectives using various adaptation techniques. Analyzing each suggested adaptation ensures that performance requirements and SLAs are continuously met. We evaluate our framework w.r.t. (i) general requirements and assessments of languages and frameworks for adaptation models, (ii) finding Pareto-optimal solutions considering a multi-dimensional cost model, and (iii) scalability. The evaluation shows that our approach detects the bottlenecks and the violated SLAs correctly, outputs valid and cost-optimal adaptations, and keeps the runtime for the adaptation process constant even with increasing network size and an increasing number of alternative configurations.
@inproceedings{HeGrRyLeKrKo2020-SIMUtools-Network-Online-Adaptation, abstract = {Today's data centers face a rapid change of deployed services, growing complexity, and increasing performance requirements. Customers expect not only round-the-clock availability of the hosted services but also high responsiveness. Besides optimizing software architectures and deployments, networks have to be adapted to handle the changing and volatile demands. Approaches from self-adaptive systems can be used for optimizing data center networks to continuously meet Service Level Agreements (SLAs) between data center operators and customers. However, existing approaches focus only on specific objectives like topology design, power optimization, or traffic engineering. In this paper, we present an extensible framework that analyzes networks using different types of simulation and adapts them subject to multiple objectives using various adaptation techniques. Analyzing each suggested adaptation ensures that performance requirements and SLAs are continuously met. We evaluate our framework w.r.t. (i) general requirements and assessments of languages and frameworks for adaptation models, (ii) finding Pareto-optimal solutions considering a multi-dimensional cost model, and (iii) scalability. The evaluation shows that our approach detects the bottlenecks and the violated SLAs correctly, outputs valid and cost-optimal adaptations, and keeps the runtime for the adaptation process constant even with increasing network size and an increasing number of alternative configurations.}, address = {Cham}, author = {Herrnleben, Stefan and Grohmann, Johannes and Rygielski, Pitor and Lesch, Veronika and Krupitzer, Christian and Kounev, Samuel}, booktitle = {Proceedings of the 12th EAI International Conference on Simulation Tools and Techniques (SIMUtools)}, editor = {Song, Houbing and Jiang, Dingde}, keywords = {descartes myown networking t_full}, month = {August}, pages = {513–532}, publisher = {Springer International Publishing}, series = {SIMUtools 2020}, title = {A Simulation-based Optimization Framework for Online Adaptation of Networks}, year = 2021 }
73.
Grigorjew, A., Gray, N., Hoßfeld, T.: Dynamic Real-Time Stream Reservation with TAS and Shared Time Windows. 2nd International Workshop on Time-Sensitive and Deterministic Networking (TENSOR) (2021).
[ Abstract ] [ BibTeX ]
 
Motivated by new use cases such as industrial automation and in-vehicle communication, Time-Sensitive Networking is further improving the layer~2 standards for real-time communication in Ethernet networks. As periodic traffic is a common requirement in such scenarios, the Time Aware Shaper (TAS) is a highly popular mechanism that allows the realization of real-time guarantees in synchronized networks. Most applications in literature suggest to configure the TAS for full stream isolation such that the lowest delays can be achieved. However, this ``zero-queuing'' strategy requires a high amount of computational resources and time, as the configuration of the gate control lists of each port is a complex task, which is not suitable for scenarios with dynamically changing requirements. This paper presents a novel approach with shared time windows. In combination with stream reservation techniques that are commonly applied for asynchronous mechanisms, the network is able to accept new streams during operation without complex reconfiguration, while still benefiting from some degree of isolation compared to conventional asynchronous shapers. The evaluation shows that, given the right circumstances, the number of accepted real-time streams can be improved significantly.
@inproceedings{info3-inproceedings-2021-7, abstract = {Motivated by new use cases such as industrial automation and in-vehicle communication, Time-Sensitive Networking is further improving the layer 2 standards for real-time communication in Ethernet networks. As periodic traffic is a common requirement in such scenarios, the Time Aware Shaper (TAS) is a highly popular mechanism that allows the realization of real-time guarantees in synchronized networks. Most applications in literature suggest to configure the TAS for full stream isolation such that the lowest delays can be achieved. However, this ``zero-queuing'' strategy requires a high amount of computational resources and time, as the configuration of the gate control lists of each port is a complex task, which is not suitable for scenarios with dynamically changing requirements. This paper presents a novel approach with shared time windows. In combination with stream reservation techniques that are commonly applied for asynchronous mechanisms, the network is able to accept new streams during operation without complex reconfiguration, while still benefiting from some degree of isolation compared to conventional asynchronous shapers. The evaluation shows that, given the right circumstances, the number of accepted real-time streams can be improved significantly.}, author = {Grigorjew, Alexej and Gray, Nicholas and Hoßfeld, Tobias}, booktitle = {2nd International Workshop on Time-Sensitive and Deterministic Networking (TENSOR)}, keywords = {myown intedis ngn}, month = 6, title = {Dynamic Real-Time Stream Reservation with TAS and Shared Time Windows}, year = 2021 }
74.
Lugrin, B.: Introduction to Socially Interactive Agents. In: Lugrin, B., Pelachaud, C., und Traum, D. (hrsg.) The Handbook on Socially Interactive Agents – 20 Years of Research on Embodied Conversational Agents, Intelligent Virtual Agents, and Social Robotics, Volume 1: Methods, Behavior, Cognition. S. 1–20. ACM (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@incollection{Lugrin_2021, author = {Lugrin, Birgit}, booktitle = {The Handbook on Socially Interactive Agents – 20 Years of Research on Embodied Conversational Agents, Intelligent Virtual Agents, and Social Robotics, Volume 1: Methods, Behavior, Cognition}, editor = {Lugrin, Birgit and Pelachaud, Catherine and Traum, David}, keywords = {MI birgit myown}, pages = {1-20}, publisher = {ACM}, title = {Introduction to Socially Interactive Agents}, year = 2021 }
75.
Büttner, J., Von Mammen, S.: Training a Reinforcement Learning Agent based on XCS in a Competitive Snake Environment. 2021 IEEE Conference on Games (CoG). S. 1–5 (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@inproceedings{Buttner:2021aa, author = {Büttner, Johannes and Von Mammen, Sebastian}, booktitle = {2021 IEEE Conference on Games (CoG)}, keywords = {imported myown}, pages = {1-5}, title = {Training a Reinforcement Learning Agent based on XCS in a Competitive Snake Environment}, year = 2021 }
76.
Kern, F., Popp, M., Kullmann, P., Ganal, E., Latoschik, M.E.: 3D Printing an Accessory Dock for XR Controllers and its Exemplary Use as XR Stylus. 27th ACM Symposium on Virtual Reality Software and Technology. S. 1–3. Association for Computing Machinery, Osaka, Japan (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
This article introduces the accessory dock, a 3D printed multipurpose extension for consumer-grade XR controllers that enables flexible mounting of self-made and commercial accessories. The uniform design of our concept opens new opportunities for XR systems being used for more diverse purposes, e.g., researchers and practitioners could use and compare arbitrary XR controllers within their experiments while ensuring access to buttons and battery housing. As a first example, we present a stylus tip accessory to build an XR Stylus, which can be directly used with frameworks for handwriting, sketching, and UI interaction on physically aligned virtual surfaces. For new XR controllers, we provide instructions on how to adjust the accessory dock to the controller’s form factor. A video tutorial for the construction and the source files for 3D printing are publicly available for reuse, replication, and extension (https://go.uniwue.de/hci-otss-accessory-dock).
@inproceedings{kern2021printing, abstract = {This article introduces the accessory dock, a 3D printed multipurpose extension for consumer-grade XR controllers that enables flexible mounting of self-made and commercial accessories. The uniform design of our concept opens new opportunities for XR systems being used for more diverse purposes, e.g., researchers and practitioners could use and compare arbitrary XR controllers within their experiments while ensuring access to buttons and battery housing. As a first example, we present a stylus tip accessory to build an XR Stylus, which can be directly used with frameworks for handwriting, sketching, and UI interaction on physically aligned virtual surfaces. For new XR controllers, we provide instructions on how to adjust the accessory dock to the controller’s form factor. A video tutorial for the construction and the source files for 3D printing are publicly available for reuse, replication, and extension (https://go.uniwue.de/hci-otss-accessory-dock).}, address = {Osaka, Japan}, author = {Kern, Florian and Popp, Matthias and Kullmann, Peter and Ganal, Elisabeth and Latoschik, Marc Erich}, booktitle = {27th ACM Symposium on Virtual Reality Software and Technology}, keywords = {myown vilearn}, pages = {1-3}, publisher = {Association for Computing Machinery}, series = {VRST '21}, title = {3D Printing an Accessory Dock for XR Controllers and its Exemplary Use as XR Stylus}, year = 2021 }
77.
BenSiSaid, K., Ababou, N., Ababou, A., Roth, D., von Mammen, S.: Tracking rower motion without on-body sensors using an instrumented machine and an artificial neural network. Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology. (2021).
[ BibTeX ] [ URL ]
 
@article{bensisaid2021tracking, author = {BenSiSaid, Karim and Ababou, Noureddine and Ababou, Amina and Roth, Daniel and von Mammen, Sebastian}, journal = {Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology}, keywords = {myown}, publisher = {SAGE Publications Sage UK: London, England}, title = {Tracking rower motion without on-body sensors using an instrumented machine and an artificial neural network}, year = 2021 }
78.
Kern, F., Keser, T., Niebling, F., Latoschik, M.E.: Using Hand Tracking and Voice Commands to Physically Align Virtual Surfaces in AR for Handwriting and Sketching with HoloLens 2. 27th ACM Symposium on Virtual Reality Software and Technology. S. 1–3. Association for Computing Machinery, Osaka, Japan (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
In this paper, we adapt an existing VR framework for handwriting and sketching on physically aligned virtual surfaces to AR environments using the Microsoft HoloLens 2. We demonstrate a multimodal input metaphor to control the framework’s calibration features using hand tracking and voice commands. Our technical evaluation of fingertip/surface accuracy and precision on physical tables and walls is in line with existing measurements on comparable hardware, albeit considerably lower compared to previous work using controller-based VR devices. We discuss design considerations and the benefits of our unified input metaphor suitable for controller tracking and hand tracking systems. We encourage extensions and replication by providing a publicly available reference implementation (https://go.uniwue.de/hci-otss-hololens).
@inproceedings{kern2021using, abstract = {In this paper, we adapt an existing VR framework for handwriting and sketching on physically aligned virtual surfaces to AR environments using the Microsoft HoloLens 2. We demonstrate a multimodal input metaphor to control the framework’s calibration features using hand tracking and voice commands. Our technical evaluation of fingertip/surface accuracy and precision on physical tables and walls is in line with existing measurements on comparable hardware, albeit considerably lower compared to previous work using controller-based VR devices. We discuss design considerations and the benefits of our unified input metaphor suitable for controller tracking and hand tracking systems. We encourage extensions and replication by providing a publicly available reference implementation (https://go.uniwue.de/hci-otss-hololens).}, address = {Osaka, Japan}, author = {Kern, Florian and Keser, Thore and Niebling, Florian and Latoschik, Marc Erich}, booktitle = {27th ACM Symposium on Virtual Reality Software and Technology}, keywords = {myown niebling vilearn}, note = {Best poster award. 🏆}, pages = {1-3}, publisher = {Association for Computing Machinery}, series = {VRST '21}, title = {Using Hand Tracking and Voice Commands to Physically Align Virtual Surfaces in AR for Handwriting and Sketching with HoloLens 2}, year = 2021 }
79.
Pfister, J., Kobs, K., Hotho, A.: Self-Supervised Multi-Task Pretraining Improves Image Aesthetic Assessment. Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR) Workshops. S. 816–825 (2021).
[ BibTeX ]
 
@inproceedings{Pfister_2021_CVPR, author = {Pfister, Jan and Kobs, Konstantin and Hotho, Andreas}, booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR) Workshops}, keywords = {2021 from:janpfister from:konstantinkobs myown}, month = {June}, pages = {816-825}, title = {Self-Supervised Multi-Task Pretraining Improves Image Aesthetic Assessment}, year = 2021 }
80.
Seufert, C., Oberdörfer, S., Roth, A., Grafe, S., Lugrin, J.-L., Latoschik, M.E.: Classroom management competency enhancement for student teachers using a fully immersive virtual classroom. Computers & Education. 104410 (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
The purpose of this study is to examine whether pre-service teachers studying classroom management (CM) in a virtual reality (VR)-supported setting enhance their CM competencies more than students do in a setting using conventional methods. With this aim in mind and to address a lack of available situations of practicing and reflecting CM competencies besides simply gaining theoretical knowledge about CM in education, we integrated a novel fully immersive VR application in selected CM courses. We evaluated the development of self-assessed and instructor-rated CM competencies and the learning quality in the different learning conditions. Additionally, we evaluated the presence, social presence, believability and utility of the VR application and the VR-assisted and video-assisted course. Participants were pre-service teachers (n = 55) of the university of XXX who participated in a quasi-experimental pre-test/post-test intervention. The students were randomly assigned to one of two intervention groups: the test group used ProjectName during the term (n = 39), and the comparison group's learning was video-assisted (n = 16). The instructor rating shows significant differences between the VR group and the video group, the two points of measurement and for the interaction between the condition and time of measurement. It demonstrates a highly significant improvement in CM competencies in the VR setting between the pre-test and post-test (p < 0.001, Cohen's d = 1.06) as compared to the video-based setting. The participants of the VR setting themselves rated their CM competencies in the post-test significantly higher than in the pre-test (p = 0.02, Cohen's d = 0.39). Interestingly, the video group also rated themselves better in the post-test (p = 0.02, Cohen's d = 0.67), which reveals that self-assessment and external assessment show different results. In addition, we observed that even if both groups gained similar theoretical knowledge, the CM competencies developed to a greater degree in the VR-based settings. The participants rated the CM training system a useful tool to evaluate and reflect on individual teacher actions. Its immersion contributes to a high presence and the simulation of realistic scenarios in a CM course. These findings suggest that VR-based settings can lead to a higher benefit in the enhancement of pre-service teachers' CM competencies.
@article{SEUFERT2021104410, abstract = {The purpose of this study is to examine whether pre-service teachers studying classroom management (CM) in a virtual reality (VR)-supported setting enhance their CM competencies more than students do in a setting using conventional methods. With this aim in mind and to address a lack of available situations of practicing and reflecting CM competencies besides simply gaining theoretical knowledge about CM in education, we integrated a novel fully immersive VR application in selected CM courses. We evaluated the development of self-assessed and instructor-rated CM competencies and the learning quality in the different learning conditions. Additionally, we evaluated the presence, social presence, believability and utility of the VR application and the VR-assisted and video-assisted course. Participants were pre-service teachers (n = 55) of the university of XXX who participated in a quasi-experimental pre-test/post-test intervention. The students were randomly assigned to one of two intervention groups: the test group used ProjectName during the term (n = 39), and the comparison group's learning was video-assisted (n = 16). The instructor rating shows significant differences between the VR group and the video group, the two points of measurement and for the interaction between the condition and time of measurement. It demonstrates a highly significant improvement in CM competencies in the VR setting between the pre-test and post-test (p < 0.001, Cohen's d = 1.06) as compared to the video-based setting. The participants of the VR setting themselves rated their CM competencies in the post-test significantly higher than in the pre-test (p = 0.02, Cohen's d = 0.39). Interestingly, the video group also rated themselves better in the post-test (p = 0.02, Cohen's d = 0.67), which reveals that self-assessment and external assessment show different results. In addition, we observed that even if both groups gained similar theoretical knowledge, the CM competencies developed to a greater degree in the VR-based settings. The participants rated the CM training system a useful tool to evaluate and reflect on individual teacher actions. Its immersion contributes to a high presence and the simulation of realistic scenarios in a CM course. These findings suggest that VR-based settings can lead to a higher benefit in the enhancement of pre-service teachers' CM competencies.}, author = {Seufert, Christian and Oberd{ö}rfer, Sebastian and Roth, Alice and Grafe, Silke and Lugrin, Jean-Luc and Latoschik, Marc Erich}, journal = {Computers & Education}, keywords = {Classroom Evaluation Immersive Initial Professionalization bbb education lugrin management myown}, pages = 104410, title = {Classroom management competency enhancement for student teachers using a fully immersive virtual classroom}, year = 2021 }
81.
Dallmann, A., Kohlmann, J., Zoller, D., Hotho, A.: Sequential Item Recommendation in the MOBA Game Dota 2. 2021 International Conference on Data Mining Workshops (ICDMW). S. 10–17 (2021).
[ Abstract ] [ BibTeX ] [ DOI ]
 
Multiplayer Online Battle Arena (MOBA) games such as Dota 2 attract hundreds of thousands of players every year. Despite the large player base, it is still important to attract new players to prevent the community of a game from becoming inactive. Entering MOBA games is, however, often demanding, requiring the player to learn numerous skills at once. An important factor of success is buying the correct items which forms a complex task depending on various in-game factors such as already purchased items, the team composition, or available resources. A recommendation system can support players by reducing the mental effort required to choose a suitable item, helping, e.g., newer players or players returning to the game after a longer break, to focus on other aspects of the game. Since Sequential Item Recommendation (SIR) has proven to be effective in various domains (e.g. e-commerce, movie recommendation or playlist continuation), we explore the applicability of well-known SIR models in the context of purchase recommendations in Dota 2. To facilitate this research, we collect, analyze and publish Dota-350k, a new large dataset based on recent Dota 2 matches. We find that SIR models can be employed effectively for item recommendation in Dota 2. Our results show that models that consider the order of purchases are the most effective. In contrast to other domains, we find RNN-based models to outperform the more recent Transformer-based architectures on Dota-350k.
@inproceedings{9679858, abstract = {Multiplayer Online Battle Arena (MOBA) games such as Dota 2 attract hundreds of thousands of players every year. Despite the large player base, it is still important to attract new players to prevent the community of a game from becoming inactive. Entering MOBA games is, however, often demanding, requiring the player to learn numerous skills at once. An important factor of success is buying the correct items which forms a complex task depending on various in-game factors such as already purchased items, the team composition, or available resources. A recommendation system can support players by reducing the mental effort required to choose a suitable item, helping, e.g., newer players or players returning to the game after a longer break, to focus on other aspects of the game. Since Sequential Item Recommendation (SIR) has proven to be effective in various domains (e.g. e-commerce, movie recommendation or playlist continuation), we explore the applicability of well-known SIR models in the context of purchase recommendations in Dota 2. To facilitate this research, we collect, analyze and publish Dota-350k, a new large dataset based on recent Dota 2 matches. We find that SIR models can be employed effectively for item recommendation in Dota 2. Our results show that models that consider the order of purchases are the most effective. In contrast to other domains, we find RNN-based models to outperform the more recent Transformer-based architectures on Dota-350k.}, author = {Dallmann, Alexander and Kohlmann, Johannes and Zoller, Daniel and Hotho, Andreas}, booktitle = {2021 International Conference on Data Mining Workshops (ICDMW)}, keywords = {2021 Dota game myown recommender}, month = {dec}, pages = {10-17}, title = {Sequential Item Recommendation in the MOBA Game Dota 2}, year = 2021 }
82.
Tritscher, J., Krause, A., Schlör, D., Gwinner, F., Von Mammen, S., Hotho, A.: A financial game with opportunities for fraud. 2021 IEEE Conference on Games (CoG). S. 1–5 (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@inproceedings{Tritscher:2021aa, author = {Tritscher, Julian and Krause, Anna and Schlör, Daniel and Gwinner, Fabian and Von Mammen, Sebastian and Hotho, Andreas}, booktitle = {2021 IEEE Conference on Games (CoG)}, keywords = {imported myown}, pages = {1-5}, title = {A financial game with opportunities for fraud}, year = 2021 }
83.
Qi, Y., Bruch, D., Krop, P., Herrmann, M.J., Latoschik, M.E., Deckert, J., Hein, G.: Social buffering of human fear is shaped by gender, social concern and the presence of real vs virtual agents. Translational psychiatry. 11, 1–10 (2021).
[ Abstract ] [ BibTeX ] [ URL ]
 
The presence of a partner can attenuate physiological fear responses, a phenomenon known as social buffering. However, not all individuals are equally sociable. Here we investigated whether social buffering of fear is shaped by sensitivity to social anxiety (social concern) and whether these effects are different in females and males. We collected skin conductance responses (SCRs) and affect ratings of female and male participants when they experienced aversive and neutral sounds alone (alone treatment) or in the presence of an unknown person of the same gender (social treatment). Individual differences in social concern were assessed based on a well-established questionnaire. Our results showed that social concern had a stronger effect on social buffering in females than in males. The lower females scored on social concern, the stronger the SCRs reduction in the social compared to the alone treatment. The effect of social concern on social buffering of fear in females disappeared if participants were paired with a virtual agent instead of a real person. Together, these results showed that social buffering of human fear is shaped by gender and social concern. In females, the presence of virtual agents can buffer fear, irrespective of individual differences in social concern. These findings specify factors that shape the social modulation of human fear, and thus might be relevant for the treatment of anxiety disorders.
@article{qi2021social, abstract = {The presence of a partner can attenuate physiological fear responses, a phenomenon known as social buffering. However, not all individuals are equally sociable. Here we investigated whether social buffering of fear is shaped by sensitivity to social anxiety (social concern) and whether these effects are different in females and males. We collected skin conductance responses (SCRs) and affect ratings of female and male participants when they experienced aversive and neutral sounds alone (alone treatment) or in the presence of an unknown person of the same gender (social treatment). Individual differences in social concern were assessed based on a well-established questionnaire. Our results showed that social concern had a stronger effect on social buffering in females than in males. The lower females scored on social concern, the stronger the SCRs reduction in the social compared to the alone treatment. The effect of social concern on social buffering of fear in females disappeared if participants were paired with a virtual agent instead of a real person. Together, these results showed that social buffering of human fear is shaped by gender and social concern. In females, the presence of virtual agents can buffer fear, irrespective of individual differences in social concern. These findings specify factors that shape the social modulation of human fear, and thus might be relevant for the treatment of anxiety disorders.}, author = {Qi, Yanyan and Bruch, Doroth{é}e and Krop, Philipp and Herrmann, Martin J and Latoschik, Marc Erich and Deckert, J{ü}rgen and Hein, Grit}, journal = {Translational psychiatry}, keywords = {myown}, number = 1, pages = {1–10}, publisher = {Nature Publishing Group}, title = {Social buffering of human fear is shaped by gender, social concern and the presence of real vs virtual agents}, volume = 11, year = 2021 }
84.
Truman, S., von Mammen, S.: Interactive Self-Assembling Agent Ensembles. Proceedings of the 1st Games Technology Summit (2021).
[ BibTeX ] [ URL ]
 
@inproceedings{TrumanvonMammen2021, author = {Truman, Samuel and von Mammen, Sebastian}, booktitle = {Proceedings of the 1st Games Technology Summit}, keywords = {imported myown}, title = {Interactive Self-Assembling Agent Ensembles}, year = 2021 }
85.
Truman, S., Seitz, J., von Mammen, S.: Stigmergic, Diegetic Guidance of Swarm Construction. 2021 IEEE International Conference on Autonomic Computing and Self-Organizing Systems Companion (ACSOS-C). S. 226–231 (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@inproceedings{Truman:2021aa, author = {Truman, Samuel and Seitz, Jakob and von Mammen, Sebastian}, booktitle = {2021 IEEE International Conference on Autonomic Computing and Self-Organizing Systems Companion (ACSOS-C)}, keywords = {imported myown}, pages = {226-231}, title = {Stigmergic, Diegetic Guidance of Swarm Construction}, year = 2021 }
86.
Tran-Gia, P., Hoßfeld, T.: Performance Modeling and Analysis of Communication Networks. Würzburg University Press, https://modeling.systems/ (2021).
[ Abstract ] [ BibTeX ]
 
This textbook provides an introduction to common methods of performance modeling and analysis of communication systems. These methods form the basis of traffic engineering, teletraffic theory, and analytical system dimensioning. The fundamentals of probability theory, stochastic processes, Markov processes, and embedded Markov chains are presented. Basic queueing models are described with applications in communication networks. Advanced methods are presented that have been frequently used in recent practice, especially discrete-time analysis algorithms, or which go beyond classical performance measures such as Quality of Experience or energy efficiency. Recent examples of modern communication networks include Software Defined Networking and the Internet of Things. Throughout the book, illustrative examples are used to provide practical experience in performance modeling and analysis. Download: https://modeling.systems/
@book{info3-book-2021-1, abstract = {This textbook provides an introduction to common methods of performance modeling and analysis of communication systems. These methods form the basis of traffic engineering, teletraffic theory, and analytical system dimensioning. The fundamentals of probability theory, stochastic processes, Markov processes, and embedded Markov chains are presented. Basic queueing models are described with applications in communication networks. Advanced methods are presented that have been frequently used in recent practice, especially discrete-time analysis algorithms, or which go beyond classical performance measures such as Quality of Experience or energy efficiency. Recent examples of modern communication networks include Software Defined Networking and the Internet of Things. Throughout the book, illustrative examples are used to provide practical experience in performance modeling and analysis. Download: https://modeling.systems/}, address = {https://modeling.systems/}, author = {Tran-Gia, Phuoc and Hoßfeld, Tobias}, booktitle = {Performance Modeling and Analysis of Communication Networks}, keywords = {myown}, publisher = {Würzburg University Press}, title = {Performance Modeling and Analysis of Communication Networks}, year = 2021 }
87.
Madeira, O., Gromer, D., Latoschik, M.E., Pauli, P.: Effects of Acrophobic Fear and Trait Anxiety on Human Behavior in a Virtual Elevated Plus-Maze. Frontiers in Virtual Reality. 2, (2021).
[ Abstract ] [ BibTeX ] [ URL ] [ DOI ]
 
The Elevated Plus-Maze (EPM) is a well-established apparatus to measure anxiety in rodents, i.e., animals exhibiting an increased relative time spent in the closed vs. the open arms are considered anxious. To examine whether such anxiety-modulated behaviors are conserved in humans, we re-translated this paradigm to a human setting using virtual reality in a Cave Automatic Virtual Environment (CAVE) system. In two studies, we examined whether the EPM exploration behavior of humans is modulated by their trait anxiety and also assessed the individuals' levels of acrophobia (fear of height), claustrophobia (fear of confined spaces), sensation seeking, and the reported anxiety when on the maze. First, we constructed an exact virtual copy of the animal EPM adjusted to human proportions. In analogy to animal EPM studies, participants (N = 30) freely explored the EPM for 5 min. In the second study (N = 61), we redesigned the EPM to make it more human-adapted and to differentiate influences of trait anxiety and acrophobia by introducing various floor textures and lower walls of closed arms to the height of standard handrails. In the first experiment, hierarchical regression analyses of exploration behavior revealed the expected association between open arm avoidance and Trait Anxiety, an even stronger association with acrophobic fear. In the second study, results revealed that acrophobia was associated with avoidance of open arms with mesh-floor texture, whereas for trait anxiety, claustrophobia, and sensation seeking, no effect was detected. Also, subjects' fear rating was moderated by all psychometrics but trait anxiety. In sum, both studies consistently indicate that humans show no general open arm avoidance analogous to rodents and that human EPM behavior is modulated strongest by acrophobic fear, whereas trait anxiety plays a subordinate role. Thus, we conclude that the criteria for cross-species validity are met insufficiently in this case. Despite the exploratory nature, our studies provide in-depth insights into human exploration behavior on the virtual EPM.
@article{madeira:2021x, abstract = {The Elevated Plus-Maze (EPM) is a well-established apparatus to measure anxiety in rodents, i.e., animals exhibiting an increased relative time spent in the closed vs. the open arms are considered anxious. To examine whether such anxiety-modulated behaviors are conserved in humans, we re-translated this paradigm to a human setting using virtual reality in a Cave Automatic Virtual Environment (CAVE) system. In two studies, we examined whether the EPM exploration behavior of humans is modulated by their trait anxiety and also assessed the individuals' levels of acrophobia (fear of height), claustrophobia (fear of confined spaces), sensation seeking, and the reported anxiety when on the maze. First, we constructed an exact virtual copy of the animal EPM adjusted to human proportions. In analogy to animal EPM studies, participants (N = 30) freely explored the EPM for 5 min. In the second study (N = 61), we redesigned the EPM to make it more human-adapted and to differentiate influences of trait anxiety and acrophobia by introducing various floor textures and lower walls of closed arms to the height of standard handrails. In the first experiment, hierarchical regression analyses of exploration behavior revealed the expected association between open arm avoidance and Trait Anxiety, an even stronger association with acrophobic fear. In the second study, results revealed that acrophobia was associated with avoidance of open arms with mesh-floor texture, whereas for trait anxiety, claustrophobia, and sensation seeking, no effect was detected. Also, subjects' fear rating was moderated by all psychometrics but trait anxiety. In sum, both studies consistently indicate that humans show no general open arm avoidance analogous to rodents and that human EPM behavior is modulated strongest by acrophobic fear, whereas trait anxiety plays a subordinate role. Thus, we conclude that the criteria for cross-species validity are met insufficiently in this case. Despite the exploratory nature, our studies provide in-depth insights into human exploration behavior on the virtual EPM.}, author = {Madeira, Octavia and Gromer, Daniel and Latoschik, Marc Erich and Pauli, Paul}, journal = {Frontiers in Virtual Reality}, keywords = {myown}, title = {Effects of Acrophobic Fear and Trait Anxiety on Human Behavior in a Virtual Elevated Plus-Maze}, volume = 2, year = 2021 }
88.
Loh, F., Mehling, N., Metzger, F., Hoßfeld, T.: LoRaPlan: A Software to Evaluate Gateway Placement in LoRaWAN. 17th International Conference on Network and Service Management. (2021).
[ Abstract ] [ BibTeX ]
 
Long Range Wide Area Network (LoRaWAN) is one of the fastest growing Internet of Things (IoT) access network solutions. One major challenge in current LoRaWAN planning is message collision due to the random channel access. To study the collision behavior in LoRaWAN, we present LoRaPlan in this demonstration. LoRaPlan is a software to evaluate gateway placement decisions by studying the collision probability. Therefore, sensor and gateway locations can be imported to create a LoRaWAN. Furthermore, existing networks can be extended by additional gateways. Based on this setup, network coverage, network quality with regard to the number of sensors a single gateway has to manage, and also transmission quality and collision probabilities can be studied. In this demonstration, first the process of network creation with gateway and sensor import and additional manual gateway placement in LoRaPlan is presented. Different adjustable parameters are shown and the influence on network coverage and collision probability is discussed. At the end of this demonstration, it is possible for the audience to place their own gateways and evaluate own placements by means of collision probability and the coverage.
@article{info3-article-2021-11, abstract = {Long Range Wide Area Network (LoRaWAN) is one of the fastest growing Internet of Things (IoT) access network solutions. One major challenge in current LoRaWAN planning is message collision due to the random channel access. To study the collision behavior in LoRaWAN, we present LoRaPlan in this demonstration. LoRaPlan is a software to evaluate gateway placement decisions by studying the collision probability. Therefore, sensor and gateway locations can be imported to create a LoRaWAN. Furthermore, existing networks can be extended by additional gateways. Based on this setup, network coverage, network quality with regard to the number of sensors a single gateway has to manage, and also transmission quality and collision probabilities can be studied. In this demonstration, first the process of network creation with gateway and sensor import and additional manual gateway placement in LoRaPlan is presented. Different adjustable parameters are shown and the influence on network coverage and collision probability is discussed. At the end of this demonstration, it is possible for the audience to place their own gateways and evaluate own placements by means of collision probability and the coverage.}, author = {Loh, Frank and Mehling, Noah and Metzger, Florian and Hoßfeld, Tobias}, journal = {17th International Conference on Network and Service Management}, keywords = {myown 5mart}, month = 10, title = {LoRaPlan: A Software to Evaluate Gateway Placement in LoRaWAN}, year = 2021 }
89.
Hotho, A., Blomqvist, E., Dietze, S., Fokoue, A., Ding, Y., Barnaghi, P.M., Haller, A., Dragoni, M., Alani, H. hrsg.: The Semantic Web - ISWC 2021 - 20th International Semantic Web Conference, ISWC 2021, Virtual Event, October 24-28, 2021, Proceedings. Springer (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@proceedings{DBLP:conf/semweb/2021, editor = {Hotho, Andreas and Blomqvist, Eva and Dietze, Stefan and Fokoue, Achille and Ding, Ying and Barnaghi, Payam M. and Haller, Armin and Dragoni, Mauro and Alani, Harith}, keywords = {2021 conference myown semantic web}, publisher = {Springer}, series = {Lecture Notes in Computer Science}, title = {The Semantic Web - {ISWC} 2021 - 20th International Semantic Web Conference, {ISWC} 2021, Virtual Event, October 24-28, 2021, Proceedings}, volume = 12922, year = 2021 }
90.
Eismann, S., Bui, L., Grohmann, J., Abad, C., Herbst, N., Kounev, S.: Sizeless: Predicting the Optimal Size of Serverless Functions. Proceedings of the 22nd International MIDDLEWARE Conference. S. 248–259 (2021).
[ Abstract ] [ BibTeX ] [ URL ]
 
Serverless functions are an emerging cloud computing paradigm that is being rapidly adopted by both industry and academia. In this cloud computing model, the provider opaquely handles resource management tasks such as resource provisioning, deployment, and auto-scaling. The only resource management task that developers are still in charge of is selecting how much resources are allocated to each worker instance. However, selecting the optimal size of serverless functions is quite challenging, so developers often neglect it despite its significant cost and performance benefits. Existing approaches aiming to automate serverless functions resource sizing require dedicated performance tests, which are time-consuming to implement and maintain. In this paper, we introduce an approach to predict the optimal resource size of a serverless function using monitoring data from a single resource size. As our approach does not require dedicated performance tests, it enables cloud providers to implement resource sizing on a platform level and automate the last resource management task associated with serverless functions. We evaluate our approach on four different serverless applications on AWS, where it predicts the execution time of the other memory sizes based on monitoring data for a single memory size with an average prediction error of 15.3%. Based on these predictions, it selects the optimal memory size for 79.0% of the serverless functions and the secondbest memory size for 12.3% of the serverless functions, which results in an average speedup of 39.7% while also decreasing average costs by 2.6%.
@inproceedings{eismann2021sizeless, abstract = {Serverless functions are an emerging cloud computing paradigm that is being rapidly adopted by both industry and academia. In this cloud computing model, the provider opaquely handles resource management tasks such as resource provisioning, deployment, and auto-scaling. The only resource management task that developers are still in charge of is selecting how much resources are allocated to each worker instance. However, selecting the optimal size of serverless functions is quite challenging, so developers often neglect it despite its significant cost and performance benefits. Existing approaches aiming to automate serverless functions resource sizing require dedicated performance tests, which are time-consuming to implement and maintain. In this paper, we introduce an approach to predict the optimal resource size of a serverless function using monitoring data from a single resource size. As our approach does not require dedicated performance tests, it enables cloud providers to implement resource sizing on a platform level and automate the last resource management task associated with serverless functions. We evaluate our approach on four different serverless applications on AWS, where it predicts the execution time of the other memory sizes based on monitoring data for a single memory size with an average prediction error of 15.3%. Based on these predictions, it selects the optimal memory size for 79.0% of the serverless functions and the secondbest memory size for 12.3% of the serverless functions, which results in an average speedup of 39.7% while also decreasing average costs by 2.6%.}, author = {Eismann, Simon and Bui, Long and Grohmann, Johannes and Abad, Cristina and Herbst, Nikolas and Kounev, Samuel}, booktitle = {Proceedings of the 22nd International MIDDLEWARE Conference}, keywords = {descartes myown t_full select}, note = {Best Student Paper Award, ACM Artifacts Evaluated — Functional}, pages = {248–259}, title = {Sizeless: Predicting the Optimal Size of Serverless Functions}, year = 2021 }
91.
Straesser, M.: Container Start Times: Empirical Analysis and Predictability. (2021).
[ BibTeX ] [ URL ]
 
@presentation{straesser2021container, author = {Straesser, Martin}, keywords = {container descartes empirical_study t_talk myown}, title = {Container Start Times: Empirical Analysis and Predictability}, year = 2021 }
92.
Dulny, A., Hotho, A., Krause, A.: NeuralPDE: Modelling Dynamical Systems from Data, http://arxiv.org/abs/2111.07671, (2021).
[ Abstract ] [ BibTeX ] [ URL ]
 
Many physical processes such as weather phenomena or fluid mechanics are governed by partial differential equations (PDEs). Modelling such dynamical systems using Neural Networks is an emerging research field. However, current methods are restricted in various ways: they require prior knowledge about the governing equations, and are limited to linear or first-order equations. In this work we propose NeuralPDE, a model which combines convolutional neural networks (CNNs) with differentiable ODE solvers to model dynamical systems. We show that the Method of Lines used in standard PDE solvers can be represented using convolutions which makes CNNs the natural choice to parametrize arbitrary PDE dynamics. Our model can be applied to any data without requiring any prior knowledge about the governing PDE. We evaluate NeuralPDE on datasets generated by solving a wide variety of PDEs, covering higher orders, non-linear equations and multiple spatial dimensions.
@misc{dulny2021neuralpde, abstract = {Many physical processes such as weather phenomena or fluid mechanics are governed by partial differential equations (PDEs). Modelling such dynamical systems using Neural Networks is an emerging research field. However, current methods are restricted in various ways: they require prior knowledge about the governing equations, and are limited to linear or first-order equations. In this work we propose NeuralPDE, a model which combines convolutional neural networks (CNNs) with differentiable ODE solvers to model dynamical systems. We show that the Method of Lines used in standard PDE solvers can be represented using convolutions which makes CNNs the natural choice to parametrize arbitrary PDE dynamics. Our model can be applied to any data without requiring any prior knowledge about the governing PDE. We evaluate NeuralPDE on datasets generated by solving a wide variety of PDEs, covering higher orders, non-linear equations and multiple spatial dimensions.}, author = {Dulny, Andrzej and Hotho, Andreas and Krause, Anna}, keywords = {2021 learning model myown network neural pde}, note = {cite arxiv:2111.07671}, title = {NeuralPDE: Modelling Dynamical Systems from Data}, year = 2021 }
93.
Herrnleben, S., Leidinger, M., Lesch, V., Prantl, T., Grohmann, J., Krupitzer, C., Kounev, S.: ComBench: A Benchmarking Framework for Publish/Subscribe Communication Protocols Under Network Limitations. In: Zhao, Q. und Xia, L. (hrsg.) Performance Evaluation Methodologies and Tools. S. 72–92. Springer International Publishing, Cham (2021).
[ Abstract ] [ BibTeX ] [ URL ]
 
Efficient and dependable communication is a highly relevant aspect for Internet of Things (IoT) systems in which tiny sensors, actuators, wearables, or other smart devices exchange messages. Various publish/subscribe protocols address the challenges of communication in IoT systems. The selection process of a suitable protocol should consider the communication behavior of the application, the protocol's performance, the resource requirements on the end device, and the network connection quality, as IoT environments often rely on wireless networks. Benchmarking is a common approach to evaluate and compare systems, considering the performance and aspects like dependability or security. In this paper, we present our IoT communication benchmarking framework ComBench for publish/subscribe protocols focusing on constrained networks with varying quality conditions. The benchmarking framework supports system designers, software engineers, and application developers to select and investigate the behavior of communication protocols. Our benchmarking framework contributes to (i) show the impact of fluctuating network quality on communication, (ii) compare multiple protocols, protocol features, and protocol implementations, and (iii) analyze scalability, robustness, and dependability of clients, networks, and brokers in different scenarios. Our case study demonstrates the applicability of our framework to support the decision for the best-suited protocol in various scenarios.
@inproceedings{10.1007/978-3-030-92511-6_5, abstract = {Efficient and dependable communication is a highly relevant aspect for Internet of Things (IoT) systems in which tiny sensors, actuators, wearables, or other smart devices exchange messages. Various publish/subscribe protocols address the challenges of communication in IoT systems. The selection process of a suitable protocol should consider the communication behavior of the application, the protocol's performance, the resource requirements on the end device, and the network connection quality, as IoT environments often rely on wireless networks. Benchmarking is a common approach to evaluate and compare systems, considering the performance and aspects like dependability or security. In this paper, we present our IoT communication benchmarking framework ComBench for publish/subscribe protocols focusing on constrained networks with varying quality conditions. The benchmarking framework supports system designers, software engineers, and application developers to select and investigate the behavior of communication protocols. Our benchmarking framework contributes to (i) show the impact of fluctuating network quality on communication, (ii) compare multiple protocols, protocol features, and protocol implementations, and (iii) analyze scalability, robustness, and dependability of clients, networks, and brokers in different scenarios. Our case study demonstrates the applicability of our framework to support the decision for the best-suited protocol in various scenarios.}, address = {Cham}, author = {Herrnleben, Stefan and Leidinger, Maximilian and Lesch, Veronika and Prantl, Thomas and Grohmann, Johannes and Krupitzer, Christian and Kounev, Samuel}, booktitle = {Performance Evaluation Methodologies and Tools}, editor = {Zhao, Qianchuan and Xia, Li}, keywords = {descartes networking t_full myown}, pages = {72&ndash;92}, publisher = {Springer International Publishing}, title = {ComBench: A Benchmarking Framework for Publish/Subscribe Communication Protocols Under Network Limitations}, year = 2021 }
94.
Lugrin, B., Rehm, M.: Culture for Socially Interactive Agents. In: Lugrin, B., Pelachaud, C., und Traum, D. (hrsg.) The Handbook on Socially Interactive Agents – 20 Years of Research on Embodied Conversational Agents, Intelligent Virtual Agents, and Social Robotics, Volume 1: Methods, Behavior, Cognition. S. 463–494. ACM (2021).
[ BibTeX ] [ URL ] [ DOI ]
 
@incollection{Lugrin_2021, author = {Lugrin, Birgit and Rehm, Matthias}, booktitle = {The Handbook on Socially Interactive Agents – 20 Years of Research on Embodied Conversational Agents, Intelligent Virtual Agents, and Social Robotics, Volume 1: Meth