2,919 research outputs found

    Deep generative models for network data synthesis and monitoring

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    Measurement and monitoring are fundamental tasks in all networks, enabling the down-stream management and optimization of the network. Although networks inherently have abundant amounts of monitoring data, its access and effective measurement is another story. The challenges exist in many aspects. First, the inaccessibility of network monitoring data for external users, and it is hard to provide a high-fidelity dataset without leaking commercial sensitive information. Second, it could be very expensive to carry out effective data collection to cover a large-scale network system, considering the size of network growing, i.e., cell number of radio network and the number of flows in the Internet Service Provider (ISP) network. Third, it is difficult to ensure fidelity and efficiency simultaneously in network monitoring, as the available resources in the network element that can be applied to support the measurement function are too limited to implement sophisticated mechanisms. Finally, understanding and explaining the behavior of the network becomes challenging due to its size and complex structure. Various emerging optimization-based solutions (e.g., compressive sensing) or data-driven solutions (e.g. deep learning) have been proposed for the aforementioned challenges. However, the fidelity and efficiency of existing methods cannot yet meet the current network requirements. The contributions made in this thesis significantly advance the state of the art in the domain of network measurement and monitoring techniques. Overall, we leverage cutting-edge machine learning technology, deep generative modeling, throughout the entire thesis. First, we design and realize APPSHOT , an efficient city-scale network traffic sharing with a conditional generative model, which only requires open-source contextual data during inference (e.g., land use information and population distribution). Second, we develop an efficient drive testing system — GENDT, based on generative model, which combines graph neural networks, conditional generation, and quantified model uncertainty to enhance the efficiency of mobile drive testing. Third, we design and implement DISTILGAN, a high-fidelity, efficient, versatile, and real-time network telemetry system with latent GANs and spectral-temporal networks. Finally, we propose SPOTLIGHT , an accurate, explainable, and efficient anomaly detection system of the Open RAN (Radio Access Network) system. The lessons learned through this research are summarized, and interesting topics are discussed for future work in this domain. All proposed solutions have been evaluated with real-world datasets and applied to support different applications in real systems

    Wearable gaming technology: A study on the relationships between wearable features and gameful experiences

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    With the parallel advancement and evolution of psycho-physiological sensors, haptics, and overall wearable computing, wearable devices have become a mainstay in everyday life. While gaming is one of the most intuitively appealing areas for using wearable devices, most gaming concepts relying on wearable devices have had only moderate success. Therefore, further knowledge is needed by game developers for innovating new gaming concepts, by wearable designers to innovate new affordances for gaming in wearables, and by gamers for seeing the possibilities of what wearables can bring to gaming. To address this research problem, we combined vignette and survey studies (N = 289) to investigate which features of wearables (integrability, wearability, modularity, sociability, programmability, bio-adaptability, audiovisuality, and embodied modality) would lead to gameful experiences. Overall, the results indicate that integrability to games, wearability, modularity, and sociability were dimensions of wearables which were most strongly connected with the expectation of a heightened game experience. The findings of the study contribute to the current understanding on the experiential value of gaming wearables, as well as providing practical guidance for gaming wearables designers and marketers.Peer reviewe

    UMSL Bulletin 2023-2024

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    The 2023-2024 Bulletin and Course Catalog for the University of Missouri St. Louis.https://irl.umsl.edu/bulletin/1088/thumbnail.jp

    UMSL Bulletin 2022-2023

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    The 2022-2023 Bulletin and Course Catalog for the University of Missouri St. Louis.https://irl.umsl.edu/bulletin/1087/thumbnail.jp

    Digital Innovations for a Circular Plastic Economy in Africa

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    Plastic pollution is one of the biggest challenges of the twenty-first century that requires innovative and varied solutions. Focusing on sub-Saharan Africa, this book brings together interdisciplinary, multi-sectoral and multi-stakeholder perspectives exploring challenges and opportunities for utilising digital innovations to manage and accelerate the transition to a circular plastic economy (CPE). This book is organised into three sections bringing together discussion of environmental conditions, operational dimensions and country case studies of digital transformation towards the circular plastic economy. It explores the environment for digitisation in the circular economy, bringing together perspectives from practitioners in academia, innovation, policy, civil society and government agencies. The book also highlights specific country case studies in relation to the development and implementation of different innovative ideas to drive the circular plastic economy across the three sub-Saharan African regions. Finally, the book interrogates the policy dimensions and practitioner perspectives towards a digitally enabled circular plastic economy. Written for a wide range of readers across academia, policy and practice, including researchers, students, small and medium enterprises (SMEs), digital entrepreneurs, non-governmental organisations (NGOs) and multilateral agencies, policymakers and public officials, this book offers unique insights into complex, multilayered issues relating to the production and management of plastic waste and highlights how digital innovations can drive the transition to the circular plastic economy in Africa. The Open Access version of this book, available at https://www.taylorfrancis.com, has been made available under a Creative Commons Attribution-Non Commercial-No Derivatives (CC-BY-NC-ND) 4.0 license

    Social Media Analytics in Disaster Response: A Comprehensive Review

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    Social media has emerged as a valuable resource for disaster management, revolutionizing the way emergency response and recovery efforts are conducted during natural disasters. This review paper aims to provide a comprehensive analysis of social media analytics for disaster management. The abstract begins by highlighting the increasing prevalence of natural disasters and the need for effective strategies to mitigate their impact. It then emphasizes the growing influence of social media in disaster situations, discussing its role in disaster detection, situational awareness, and emergency communication. The abstract explores the challenges and opportunities associated with leveraging social media data for disaster management purposes. It examines methodologies and techniques used in social media analytics, including data collection, preprocessing, and analysis, with a focus on data mining and machine learning approaches. The abstract also presents a thorough examination of case studies and best practices that demonstrate the successful application of social media analytics in disaster response and recovery. Ethical considerations and privacy concerns related to the use of social media data in disaster scenarios are addressed. The abstract concludes by identifying future research directions and potential advancements in social media analytics for disaster management. The review paper aims to provide practitioners and researchers with a comprehensive understanding of the current state of social media analytics in disaster management, while highlighting the need for continued research and innovation in this field.Comment: 11 page

    Microcredentials to support PBL

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    AktivitÀtstracker im Alltag: Charakteristika von Motivation und User Diversity zur ErklÀrung individueller Nutzungstrajektorien

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    Die fortlaufend stĂ€rkere Durchdringung unseres Alltags mit digitalen Technologien wird besonders deutlich durch tragbare GerĂ€te wie Smartphones, auf die jederzeit zugegriffen werden kann. Noch einen Schritt weiter gehen körpernah getragene, vernetzte Self-Tracking-Systeme wie AktivitĂ€tstracker, welche kontinuierlich Bewegungsdaten und physiologische Parameter erfassen, algorithmisch aufbereiten und an die Nutzer*innen als quantifiziertes Feedback, oft zur Verhaltensmodifikation, zurĂŒckmelden. Diese spezifische Form der Interaktion zwischen Mensch und Technologie – körpernah, kontinuierlich, quantifiziert, vernetzt und persuasiv – ist fĂŒr die Ingenieurpsychologie besonders relevant, da sie eine sehr enge Verbindung von Körper und Technik erfordert und spezifische Herausforderungen fĂŒr die StĂ€rkung der Selbstbestimmung ihrer Nutzer*innen bereithĂ€lt. Einerseits dienen AktivitĂ€tstracker der erleichterten Selbstreflexion durch Sichtbarmachung von ZusammenhĂ€ngen, die zuvor verborgen blieben, wie etwa zwischen sportlicher AktivitĂ€t und Ruheherzfrequenz. Andererseits sollen AktivitĂ€tstracker die Motivation fĂŒr körperliche VerhaltensĂ€nderungen steigern. Die Nutzung von AktivitĂ€tstrackern bewegt sich also potenziell in einem Spannungsfeld zwischen der Steigerung von Selbstbestimmung durch erweitertes Wissen sowie Aufzeigen von Handlungsoptionen und der EinschrĂ€nkung der Selbstbestimmung durch persuasive Strategien zur Motivationssteigerung. Dieses Spannungsfeld bedingt neue AnsĂ€tze zur Beziehungsgestaltung zwischen Mensch und Trackingsystem. In der empirischen Forschung zur Nutzung von AktivitĂ€tstrackern wird hĂ€ufig darauf hingewiesen, dass ein Großteil der Nutzenden nach wenigen Wochen oder Monaten den kontinuierlichen Gebrauch beendet. Dieser Befund deutet daraufhin, dass Barrieren existieren, die die Langzeitnutzung unwahrscheinlicher machen. Des Weiteren wird immer wieder ĂŒber negative Effekte der Trackernutzung berichtet, beispielsweise Stress. Allerdings ist auch bekannt, dass zahlreiche andere Personen ihr Trackingsystem ĂŒber Jahre hinweg intensiv und erfolgreich gebrauchen. Es lĂ€sst sich also in Bezug auf die Nutzungstrajektorien eine bedeutsame Varianz feststellen, die es zu erklĂ€ren gilt, um Self-Tracking-Anwendungen fĂŒr diverse Nutzende gewinnbringend zu gestalten. Um diesem Vorhaben gerecht zu werden, ist es unabdingbar zu verstehen, welche individuellen Differenzen in der Gruppe der Nutzer*innen die Interaktion mit dem AktivitĂ€tstracker, insbesondere in Bezug auf motivationale Aspekte, prĂ€gen. Dieser Herausforderung stellt sich die vorliegende Dissertation und greift dazu auf etablierte Theorien und Konzepte der Persönlichkeits- und Sozialpsychologie zurĂŒck. Da der theoriegeleitete Einbezug von Personenmerkmalen in die ingenieurpsychologische Forschung noch wenig vorangetrieben war, bestand zu Beginn des Promotionsvorhabens die Notwendigkeit, ein Konstrukt zu konzeptualisieren, welches zum einen auf einem stabilen psychologischen Theoriefundament steht und zum anderen spezifisch auf den Kontext der Mensch-Technik-Interaktion zugeschnitten ist. Im Rahmen der vorliegenden Dissertation wurde aus diesem Grund an der Herleitung der interaktionsbezogenen TechnikaffinitĂ€t (ATI) als kontextspezifische Variante der Denkfreude und ihrer Messbarmachung gearbei-tet. Insgesamt umfassten die Datenerhebungen zur Bestimmung der GĂŒtekriterien der ATI-Skala fĂŒnf DatensĂ€tze mit ĂŒber 1500 Teilnehmenden. Das Resultat der Skalenentwicklung ist ein unidimensionales, ökonomisches, reliables und valides Erhebungsinstrument der interaktionsbezogenen TechnikaffinitĂ€t (Artikel 1). Als relativ stabiles Persönlichkeitsmerkmal, das die Motivation zur Auseinandersetzung mit Technik grundlegend beeinflusst, wurde ATI in die folgenden Studien zur Interaktion zwischen Mensch und AktivitĂ€tstracker miteinbezogen. Um die alltĂ€gliche, individuelle Mensch-Tracker-Interaktion umfassend zu verstehen und erklĂ€ren zu können, wie es zu den unterschiedlichen NutzungsverlĂ€ufen kommt, mĂŒssen verschiedene Phasen der Nutzung untersucht werden. ZunĂ€chst ist zu klĂ€ren, welche Motivatoren Menschen eigentlich dazu veranlassen, mit der Trackernutzung zu beginnen. Weiterhin ist die Nutzungsphase selbst zu beleuchten, um zu beschreiben, wie sich die oben beschriebene, spezifische Form der Trackerinteraktion auf die Nutzungserfahrung und anhaltende Motivation auswirkt und wie sich negative Nutzungskonsequenzen bemerkbar machen. Schließlich sind zum VerstĂ€ndnis der Nutzungstrajektorien die GrĂŒnde fĂŒr den Abbruch zu berĂŒcksichtigen, sodass auch die Phase nach der Nutzung relevant ist. Da sich diese Dissertation dezidiert damit beschĂ€ftigt, wie sich die Interaktion mit AktivitĂ€tstrackern im Alltag gestaltet, ist die Untersuchung der Nutzung in Stichproben von tatsĂ€chlichen bzw. ehemaligen AktivitĂ€tstracker-Nutzer*innen angezeigt. Aus diesem Grund wurden zwei Online-Erhebungen durchgefĂŒhrt, um ebendiese Stichproben zu erreichen. Das Ziel der ersten Studie (N = 210) war die quantitative Analyse von Nutzungsmotivationen sowie unintendierten, negativen Effekten der Trackernutzung im Alltagsgebrauch. Es zeigte sich, dass das Tracken sowohl zum Selbstzweck (intrinsische Motivation) als auch zur Erreichung eines externen Ziels (extrinsische Motivation) durchgefĂŒhrt wird und diese Motivationstypen oft gleichzeitig auftreten. DarĂŒber hinaus konnte gezeigt werden, dass negative Effekte in Form von Motivationsverlusten in Bezug auf die Trackernutzung und die körperliche AktivitĂ€t eine Rolle im Alltag vieler Nutzer*innen spielen. Die Wahrscheinlichkeit des Auftretens dieser Effekte wird teilweise von Personenmerkmalen wie ATI und der Nutzungsmotivation bestimmt (Artikel 2). Die zweite Studie nahm ehemalige Nutzer*innen (N = 159) in den Blick und fokussierte auf die Erfassung der GrĂŒnde fĂŒr den Nutzungsabbruch sowie die StabilitĂ€t der Abbruchentscheidung. Die Ergebnisse machten deutlich, dass zahlreiche Nutzungsbarrieren fĂŒr die Entscheidung, den Tracker abzulegen, ausschlaggebend sind. Außerdem sind die Abbruchentscheidungen oft nicht permanent, was auf eine episodische Trackernutzung hindeutet (Artikel 3). Schließlich wurden wiederum Personenmerkmale und außerdem Interaktionscharakteristika in Betracht gezogen, um die große Varianz hinsichtlich AbbruchgrĂŒnden und -permanenz zu erklĂ€ren. Die Analysen offenbarten unter anderem, dass eine episodische Nutzung (d. h. nicht endgĂŒltige Beendigung) wahrscheinlicher ist, wenn sich die Nutzungsmotivation durch einen hohen Grad an Selbstbestimmung auszeichnet (Artikel 4). Abschließend betonen die Befunde der Dissertation die zentrale Rolle der wahrgenommenen Selbstbestimmung im Kontext der Mensch-Tracker-Interaktion und geben Anlass fĂŒr Designrichtlinien, die die Beziehung zwischen Trackingsystem und Nutzer*in mit all ihren gegenseitigen AbhĂ€ngigkeiten und individuellen Merkmalen berĂŒcksichtigen, um so die Selbstbestimmung zu erhalten oder sogar durch vertieftes Selbstwissen zu stĂ€rken.The ongoing permeation of our daily life with digital technologies is particularly evident in wearable devices such as smartphones, which can be accessed at any time. Wearable, connected self-tracking systems such as activity trackers go even a step further. They continuously record movement data and physiological parameters, process them algorithmically and provide quantified feedback to the user, often for behavioral modification. This specific form of interaction between humans and technology – close to the body, continuous, quantified, connected, and persuasive – is particularly relevant for engineering psychology, as it requires a very close connection between body and technology and poses specific challenges for strengthening the self-determination of its users. That is, on the one hand, activity trackers serve to facilitate self-reflection by revealing relationships which were previously hidden, such as the relationship between physical activity and resting heart rate. On the other hand, activity trackers are intended to enhance motivation for physical behavioral changes. The use of activity trackers thus potentially moves in a field of tension between the increase of self-determination through expanded knowledge as well as the identification of behavioral options and the restriction of self-determination through persuasive strategies to increase motivation. This tension requires new approaches to the design of relationships between people and tracking systems. Empirical research on activity tracker usage often highlights that a large proportion of users stop continuous use after a few weeks or months. This finding suggests the existence of barriers that make long-term use less likely. Furthermore, negative effects of tracker use, such as stress, are repeatedly reported. However, it is also known that many other users have enjoyed intensive and successful use of their tracking system for many years. Thus, a significant variance in usage trajectories can be observed, which needs to be explained in order to make self-tracking applications beneficial for diverse users. To meet this goal, it is essential to understand which individual differences in the group of users shape the interaction with their activity tracker, especially with respect to motivational aspects. This dissertation addresses this challenge by drawing on established theories and concepts of personality and social psychology. At the beginning of the dissertation project, the theory-based inclusion of personal characteristics in engineering psychology had not yet been sufficiently advanced. Thus, there was a need to conceptualize a construct which, on the one hand, stands on a stable psychological theoretical foundation and, on the other hand, is specifically tailored to the context of human-technology interaction. For this reason, the conceptualization of affinity for technology interaction (ATI) as a context-specific variant of need for cognition and its measurability took place within the context of the dissertation. In total, the data collection to determine the quality criteria of the ATI scale comprised five data sets with over 1500 participants. The result of the scale development is a unidimensional, economical, reliable, and valid survey instrument of ATI (Article 1). As a relatively stable personality trait that fundamentally influences motivation to engage with technology, ATI was included in subsequent studies of human-activity tracker interaction. In order to comprehensively understand the everyday, individual human-tracker interaction and to be able to explain how the various usage patterns occur, different phases of usage must be examined. First, it must be clarified which motivators actually cause a person to start using a tracker. Furthermore, the usage phase itself must be examined to describe how the specific form of tracker interaction described above affects the usage experience and ongoing motivation, and how negative usage consequences become apparent. Finally, to understand usage trajectories, the reasons for discontinuation need to be considered, hence the post-usage phase is also relevant. Since this dissertation decidedly focuses on the interaction with activity trackers in everyday life, the investigation of actual or former activity tracker users is indicated. For this reason, two online surveys were conducted to assess these actual (former) users. The aim of the first study (N = 210) was to quantitatively analyze motivations for usage as well as unintended, negative effects of tracker usage in daily use. It was shown that tracking is performed both for an end in itself (intrinsic motivation) and to achieve an external goal (extrinsic motivation), and that these motivation types often occur simultaneously. Furthermore, it was shown that negative effects in terms of motivation losses with respect to tracker use as well as physical activity play a role in many users' daily lives. The likelihood of these effects occurring is partly determined by personal characteristics such as ATI and motivation for usage (Article 2). The second study examined former users (N = 159) and focused on the reasons for discontinuing use and the stability of abandonment. The results indicated that numerous barriers to use are decisive for the decision to discontinue tracking. In addition, abandonment decisions are often not permanent, suggesting episodic tracker use (Article 3). Finally, person and interaction characteristics were considered to explain the large variance in abandonment reasons and permanence. The analyses revealed, among other things, that episodic use (i.e., not definitive termination) is more likely when the motivation for usage is characterized by a high degree of self-determination (Article 4). In conclusion, the findings of the dissertation emphasize the central role of perceived self-determination in the context of human-tracker interaction and give rise to design guidelines that take into account the relationship between the tracking system and the user with all its interdependencies and individual characteristics in order to preserve or even strengthen self-determination through deeper self-knowledge

    Quality of experience and access network traffic management of HTTP adaptive video streaming

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    The thesis focuses on Quality of Experience (QoE) of HTTP adaptive video streaming (HAS) and traffic management in access networks to improve the QoE of HAS. First, the QoE impact of adaptation parameters and time on layer was investigated with subjective crowdsourcing studies. The results were used to compute a QoE-optimal adaptation strategy for given video and network conditions. This allows video service providers to develop and benchmark improved adaptation logics for HAS. Furthermore, the thesis investigated concepts to monitor video QoE on application and network layer, which can be used by network providers in the QoE-aware traffic management cycle. Moreover, an analytic and simulative performance evaluation of QoE-aware traffic management on a bottleneck link was conducted. Finally, the thesis investigated socially-aware traffic management for HAS via Wi-Fi offloading of mobile HAS flows. A model for the distribution of public Wi-Fi hotspots and a platform for socially-aware traffic management on private home routers was presented. A simulative performance evaluation investigated the impact of Wi-Fi offloading on the QoE and energy consumption of mobile HAS.Die Doktorarbeit beschĂ€ftigt sich mit Quality of Experience (QoE) – der subjektiv empfundenen DienstgĂŒte – von adaptivem HTTP Videostreaming (HAS) und mit Verkehrsmanagement, das in Zugangsnetzwerken eingesetzt werden kann, um die QoE des adaptiven Videostreamings zu verbessern. Zuerst wurde der Einfluss von Adaptionsparameters und der Zeit pro QualitĂ€tsstufe auf die QoE von adaptivem Videostreaming mittels subjektiver Crowdsourcingstudien untersucht. Die Ergebnisse wurden benutzt, um die QoE-optimale Adaptionsstrategie fĂŒr gegebene Videos und Netzwerkbedingungen zu berechnen. Dies ermöglicht Dienstanbietern von Videostreaming verbesserte Adaptionsstrategien fĂŒr adaptives Videostreaming zu entwerfen und zu benchmarken. Weiterhin untersuchte die Arbeit Konzepte zum Überwachen von QoE von Videostreaming in der Applikation und im Netzwerk, die von Netzwerkbetreibern im Kreislauf des QoE-bewussten Verkehrsmanagements eingesetzt werden können. Außerdem wurde eine analytische und simulative Leistungsbewertung von QoE-bewusstem Verkehrsmanagement auf einer Engpassverbindung durchgefĂŒhrt. Schließlich untersuchte diese Arbeit sozialbewusstes Verkehrsmanagement fĂŒr adaptives Videostreaming mittels WLAN Offloading, also dem Auslagern von mobilen VideoflĂŒssen ĂŒber WLAN Netzwerke. Es wurde ein Modell fĂŒr die Verteilung von öffentlichen WLAN Zugangspunkte und eine Plattform fĂŒr sozialbewusstes Verkehrsmanagement auf privaten, hĂ€uslichen WLAN Routern vorgestellt. Abschließend untersuchte eine simulative Leistungsbewertung den Einfluss von WLAN Offloading auf die QoE und den Energieverbrauch von mobilem adaptivem Videostreaming
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