An important goal of Educational Data Mining is to provide data and visualization about students’ state of knowledge and students’ affective states. The combination of these provides an understanding of the easiness or hardness of the concepts being taught and the student’s comfortability in it. While various studies have been conducted on estimating students’ knowledge and affect, little research has been done to transform this collected (Raw) data into meaningful information that is more relatable to teachers, parents and other stakeholders, i.e. Non-Researchers. This research seeks to enhance existing Teacher Tools (An application designed within the MathSpring - An Intelligent Tutoring system) to generate a live dashboard for teachers to use in the classroom, as their students are using MathSpring. The system captures student performance and detects students’ facial expressions, which highlight students emotion and engagement, using a deep learning model that detects facial expressions. The live dashboard enables teachers to understand and juxtapose the state of knowledge and corresponding affect of students as they practice math problem solving. This should help teachers understand students’ state of mind better, and feed this information back to act and alter their instruction or interaction with each student in a personalized way. We present results of teachers' perceptions of the usefulness of the Live Dashboard, through a qualitative and quantitative survey.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22301号 / 医博第4542号 / 新制||医||1040(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 渡邊 直樹, 教授 椛島 健治, 教授 林 康紀 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Migrer à chaud une machine virtuelle (VM) est une opération basique dans un centre de données. Tous les jours, des VM sont migrées pour répartir la charge, économiser de l'énergie ou préparer la maintenance de serveurs. Bien que les problèmes de placement des VM soient beaucoup étudiés, on observe que la gestion des migrations permettant de transiter vers ces nouveaux placements reste un domaine de second plan. Cette phase est cependant critique car chaque migration à un coût en terme de CPU, de bande passante et d'énergie. Des algorithmes de décision reposent alors sur des hypothèses irréalistes et calculent des ordonnancements conduisant à des migrations longues et incontrôlables qui réduisent les bénéfices attendus de la ré-organisation des VM.Dans cette thèse nous nous sommes fixé comme objectif d'améliorer la qualité des ordonnancements de migrations dans les centres de données. Pour cela, nous avons d'abord modélisé l'ordonnancement de migrations en considérant l'architecture réseau et l'activité mémoire des VM. Pour évaluer l'efficacité de notre modèle, nous avons ensuite implémenté un ordonnanceur de migrations au sein du gestionnaire de VM BtrPlace. Nous avons ensuite étendu notre ordonnanceur en développant des contraintes d'ordonnancement, des objectifs personnalisés, une heuristique de recherche ainsi qu'un modèle énergétique.Nous avons validé notre approche par l'étude pratique de scénarios d'ordonnancement réalisés en environnement réel. Nous avons ainsi pu analyser la précision de notre modèle de migration, valider la qualité des décisions prises par notre modèle d'ordonnancement et évaluer l'extensibilité ainsi que le passage à l'échelle de notre solution / A live-migration of a virtual machine (VM) is a basic operation in a data center. Every day, VMs are migrated to distribute the load, save energy or prepare maintenance operations on production servers. Although VM placement problems have been extensively studied, we observe that the migrations management needed to apply these new placements did not get much attention. This phase is however critical as each migration has a cost in terms of CPU, bandwidth and energy. Decision algorithms are thus based on unrealistic assumptions and compute schedules which can lead to unnecessarily long and uncontrollable migrations. This reduces the ultimate benefits expected from the VMs re-organization.In this thesis, our main ojective is to improve the efficiency of live-migrations scheduling within data centers. To achieve our goal, we have first modeled the scheduling of live migrations based on the network architecture and the VMs memory activity. To evaluate the efficiency of our model, we have then implemented and optimized a migrations scheduler within the VMs manager BtrPlace. We have then extended our scheduler by developing scheduling constraints, custom objectives, a search heuristic and an energy model.We have validated our approach by the practical study of many scheduling scenarios executed in a real environment. We have then analyzed the accuracy of our migration model, assessed the quality of the decisions taken by our scheduling model, and evaluated the extensibility and the scalability of our solution

Aus der Ablehnung Positives schaffen – um die beim Bibliothekskongress 2016 nicht angenommenen Beiträge dennoch in der Öffentlichkeit zu platzieren, wurde mit dem Bibcast im Vorfeld des Kongresses ein neues, erfolgreiches Forum geschaffen. Die Resonanz war positiv, der Zuspruch groß. Nächstes Jahr soll eine Fortsetzung folgen.

This study was conducted to assess physical and perceptual properties of a tactile display for a vibrotactile notification system within the CIRMMT Live Electronics Framework (CLEF), a Max-based modular environment for composition and performance of live electronic music. The tactile display was composed of two rotating eccentric mass actuators driven by a PWM signal generated from an Arduino microcontroller. Physical measurements using an accelerometer were carried out in order to estimate intensity and spectral peak frequency as function of duty cycle of the PWM signal. In addition, three user-based studies were conducted to estimate perceptual vibrotactile absolute threshold, differential threshold and temporal differential threshold. Obtained results provided us with precise guidelines that facilitate the design of perceptually robust vibrotactile stimuli for our tactile application. A set of eight simple tactons (vibrotactile icons) was defined, whereafter an absolute identification test was conducted in order to estimate mean tacton recognition rates. Results were promising; mean tacton recognition rate was found to be 74 %. Based on all findings described above, a Max-based prototype used for exploration of tactile stimuli was developed. The prototype contained a library of tactile notification presets to be loaded into CLEF, along with a simple tacton editor for design of customized tactile events. / Syftet med denna studie var att undersöka fysiska och perceptuella egenskaper hos en taktil display som designats för att presentera taktila notifikationssignaler till användare av CIRMMT Live Electronics Framework (CLEF), en Max-baserad modulär miljö för komposition och framförande av musikstycken som involverar Live Electronics. Live Electronics är ett begrepp som innefattar elektronik som används för att generera, processera eller modifiera ljud i realtid. Den taktila display som användes i denna studie var uppbyggd av två roterande excentriska massor, drivna av en pulsbreddsmodulerad signal som genereras av en Arduino mikrokontroller. Accelerometermätningar och tre användarbaserade studier genomfördes för att undersöka följande: intensitet och spektral toppfrekvens som funktion av pulskvot, sensorisk tröskel och intensitetsdiskriminering mellan presenterade stimuli, samt JND i millisekunder för två efterföljande taktila stimuli. Erhållna resultat analyserades varefter riktlinjer för design av perceptuellt robusta signaler för vår taktila display sattes upp. I slutfasen av studien designades åtta taktila signaler, varefter en användarbaserad studie genomfördes för att uppskatta hur lätta dessa signaler var att identifiera. En genomsnittlig identifikationsnivå på 74 % kunde noteras. Baserat på ovan beskrivna resultat utvecklades slutligen en taktil modulprototyp i form av ett bibliotek av fördefinierade taktila stimuli. Denna prototyp inkluderande även en funktion som gav användaren möjlighet att designa och skräddarsy egna taktila signaler.

Adaptive streaming approaches over Hypertext Transfer Protocol (HTTP), such as Apple's HTTP Live streaming (HLS) and Microsoft's Live Smooth Streaming, have recently become very popular. This master's thesis project developed and evaluated several media rate adaptation algorithms optimized for mobile networks with a client running on Google's Android operating system. The deployed service supports HLS and the emerging ISO/IEC MPEG standard called Dynamic Adaptive Streaming over HTTP (MPEG-DASH). Live media was the focus of the evaluation, since this content can not be cached in advance at the user's device, hence the quality of the user's experience will be affected by the currently available bandwidth which the user can utilize. Experiments were performed for multiples scenarios illustrating different network capabilities, especially various amounts of bandwidth available to the user. This project has produced an implementation of HTTP-based adaptive streaming. This implementation follows the MPEG standard and enables robust and smooth playback of live video content via Google's Android devices. Results of the experiments have shown that the proposed adaptation mechanisms efficiently utilize the available bandwidth of the network. A clear conclusion of this thesis is that adaptive streaming will in fact enable substantial numbers of users to enjoy live media streaming to their devices / Adaptiv strömnings metoder över Hypertext Transfer Protocol (HTTP), till exempel Apples HTTP Live streaming (HLS) och Microsoft Live Smooth Streaming, har nyligen blivit mycket populära. Detta examensarbete utvecklas och utvärderar flera medier algoritmer anpassning av överföringshastigheten optimerad för mobila nätverk med en klient som körs på Googles Android-operativsystem. Systemet kommer att överväga HLS och den framväxande ISO/IECMPEG-standarden som kallas Dynamisk Adaptiv Strömmande över HTTP (MPEG-DASH). Direktsänd media var i fokus för utvärderingen, eftersom detta innehåll inte kan cachas i förväg på användarens enhet, därmed kvaliteten på användarens upplevelse kommer att påverkas av den aktuella tillgängliga bandbredden som användaren kan utnyttja. Experimenten utfördes för flera scenarier och illustrerar olika nätverksfunktioner, särskilt hur olika mängder bandbredd är tillgänglig för användaren. Detta projekt har producerat ett genomförande av HTTP-baserade adaptiva strömning. Denna implementering följer MPEG-standarden och möjliggör robusta och smidig uppspelning av direktsänd video innehåll via Googles Android-enheter. Resultat av experiment har visat att den föreslagna anpassningsmekanismerna effektiva sätt att utnyttja den tillgängliga bandbredden i nätverket. En tydlig slutsats i denna avhandling är att adaptive strömning faktiskt kommer att möjliggöra ett stort antal användare att njuta av direktsänd medieströmning till sina enheter.

IPTV is gaining increasing attention. It is an expanding field where a lot of people are working hard to solve the problems that delay its wide-spread use. One major problem is that the existing IPTV distribution mechanisms do not seem to work well when applied on a large scale. Especially, IP multicast does not seem to meet the requirements of highly demanding IPTV services. In contrast, peer-to-peer architectures for distributing content have been available for a number of years (since the late 1990’s), and their success suggests that this is a promising alternative means of distributing content. Although peer-to-peer architectures are well known for file transfer, this kind of architecture has been used in this thesis for distributing streaming video flows. We combine results from two different approaches - IPTV and peer-to-peer systems - as part of our design and implementation of a new solution for distributing IPTV. Our proposal aims to avoid any weaknesses that the existing solutions have, whilst offering a viable solution for distributing live content. / Intresset kring IPTV ökar hela tiden, och många människor arbetar på att lösa de problem som hindrar området från att växa snabbt. Ett av huvudproblemen är att den existerande IPTV-distributionstekniken inte fungerar bra då den appliceras på stora lösningar. Bland de största problemen är att IP-Multicast inte möter de krav som marknaden ställer på global distribution av material. I motsats till detta har peer-to-peer teknik, som funnits sedan 90-talet, visat sin styrka för fil distribution på en mycket global skala på existerande infrastruktur. I denna uppstats kombinerar vi dessa två områden för att utröna vilka möjligheterna som finns för att optimera kostnaden för distrubition av live-tv samtidigt som vi försöker att undvika de svagheter som normalt associeras med de olika arkitekturerna. Vårt mål är att utnyttja de bästa egenskaperna från de olika teknikerna för att skapa en livsduglig och långsiktig lösning för TV-distribution.

The ever increasing demand for video content directed the focus of researchfrom traditional server-based schemes to peer-to-peer systems for videodelivery. In such systems, video data is delivered to the users by utilizing theresources of the users themselves, leading to a potentially scalable solution.Users connect to each other, forming a p2p overlay network on top of theInternet and exchange the video segments among themselves. The performanceof a p2p system is characterized by its capability to deliver the videocontent to all peers without errors and with the smallest possible delay. Thisconstitutes a challenge since peers dynamically join and leave the overlay andalso contribute different amounts of resources to the system.The contribution of this thesis lies in two areas. The first area is theperformance evaluation of the most prominent p2p streaming architectures.We study the streaming quality in multiple-tree-based systems. We derivemodels to evaluate the stability of a multiple tree overlay in dynamic scenariosand the efficiency of the data distribution over the multiple trees. Then, westudy the data propagation in mesh-based overlays. We develop a generalframework for the evaluation of forwarding algorithms in such overlays anduse this framework to evaluate the performance of four different algorithms.The second area of the thesis is a study of streaming in heterogeneous p2poverlays. The streaming quality depends on the aggregate resources that peerscontribute to the system: low average contribution leads to low streamingquality. Therefore, maintaining high streaming quality requires mechanismsthat either prohibit non-contributing peers or encourage contribution. In thisthesis we investigate both approaches. For the former, we derive a model tocapture the evolution of available capacity in an overlay and propose simpleadmission control mechanisms to avoid capacity drainage. For the latter, inour last work, we propose a novel incentive mechanism that maximizes thestreaming quality in an overlay by encouraging highly contributing peers tooffer more of their resources. / QC 20100506

Historically virtual machines have been the backbone of the cloud-industry, allowing cloud-providers to offer virtualized multi-tenant solutions. A key aspect of the cloud is its flexibility and abstraction of the underlying hardware. Virtual machines can enhance this aspect by enabling support for live migration and failover. Live migration is the process of moving a running virtual machine from one host to another and failover ensures that a failed virtual machine will automatically be restarted (possibly on another host). Today, as containers continue to increase in popularity and make up a larger portion of the cloud, often replacing virtual machines, it becomes increasingly important for these processes to be available to containers as well. However, little support for container live migration and failover exists and remains largely experimental. Furthermore, no solution seems to exists that offers both live migration and failover for containers in a unified solution. The thesis presents a proof-of-concept implementation and description of a system that enables support for both live migration and failover for containers by extending current container migration techniques. It is able to offer this to any OCI-compliant container, and could therefore potentially be integrated into current container and container orchestration frameworks. In addition, measurements for the proof-of-concept implementation are provided and used to compare the proof-of-concept implementation to a current container migration technique. Furthermore, the thesis presents an overview of the history and implementation of containers, current migration techniques, and metrics that can be used for measuring different migration techniques are introduced. The paper concludes that current container migration techniques can be extended in order to support both live migration and failover, and that in doing so one might expect to achieve a downtime equal to, and total migration time lower than that of pre-copy migration. Supporting both live migration and failover, however, comes at a cost of an increased amount of data needed to be transferred between the hosts.

Live shopping is a relatively new phenomenon that combines live streaming with online shopping. Past research has explored live shopping as a functional marketing tool, used to increase sales and purchase intention. The purpose of this study was to explore consumers’ perspectives on live shopping as an experience, with the experience economy theory as a lens. Furthermore, this study utilized the four realms of an experience and five principles of design to analyze and explain the collected data. The empirical data was gathered through semi-structured interviews with respondents aged 18-27. The findings showed that consumers perceive the live shopping experience as mostly educational in conjunction with aspects of entertainment. Escapist and esthetic aspects are considered complementary and can strengthen the experience. This study contributes to an increased understanding of the live shopping experience from consumers’ perspectives. In addition, the theory of experience economy has not been previously applied to live shopping. In turn, this study has contributed to an increased use of experience economy theory in areas other than tourism and hospitality.