On a daily basis humans interact with an increasing variety of personal electronic devices, ranging from laptops, tablets, smartphones, and e-readers to shared devices such as projected displays and interactive, digital tabletops. An emerging area of study focuses on understanding how these devices can be used together to support collaborative work. Where prior research has shown benefits of devices used individually, there is currently a lack of understanding of how devices should be used in conjunction to optimize a group's performance. In particular, the research presented in this dissertation combines qualitative and quantitative analyses of group work in three empirical studies to link the use of shared and personal devices to changes in group performance and process. In the first study, participants performed an optimization task with either a single, shared projected display or with the shared, projected display and personal laptops. Analyses of study data indicated that when personal displays were present, group performance was improved for the optimization task ($p = 0.025$). However, personal devices also reduced a group's ability to coordinate ($p = 0.016$). Additionally, when personal devices were present, individuals primarily used those devices instead of dividing time between their laptops and the shared display. To further investigate the support that shared displays provide groups, and in particular, how shared displays might support group work in multi-display settings, a follow-up study was conducted. The second study investigated how two different types of shared displays supported group work. In particular, shared workspaces, which allowed multiple users to simultaneously interact with shared content, and status displays, which provided awareness of the overall problem state to groups, were investigated. While no significant impact on group performance was observed between the two shared display types, qualitative analysis of groups working in these conditions provided insight into how the displays supported collaborative activities. Shared workspace displays provided a visual reference that aided individuals in grounding communication with their collaborators. On the other hand, status displays enabled the monitoring of a group's overall task progress. Regardless of which display was present, an individual's gaze and body position relative to the shared display supported the synchronization of group activities. Finally, where the previous two studies identified collaborative activities that were supported by the use of shared and personal displays, the experimental task performed by participants did not explore the transfer of task materials between shared and personal devices or alternative personal and shared devices. The third study addressed these limitations through the adoption of a new experimental task that enabled the exploration of how the manipulation of task artefacts supported collaborative activities, and alternative shared and personal devices in the form of interactive digital tabletops and tablet computers. In particular, the third study compared how personal and shared displays supported sensemaking groups working under three conditions: with shared, digital tables, with shared digital tables plus personal tablets, and with only personal tablets. Quantitative analyses revealed that the presence of the shared, digital tabletop significantly improved a group's ability to perform the sensemaking task ($p = 0.019$). Further, qualitative analyses revealed that the table supported key sensemaking activities: the prioritization of task materials, the ability to compare data, and the formation of group hypotheses. This dissertation makes four primary contributions to the field of Computer Supported Cooperative Work. First, it identifies cases where the presence of shared and personal displays provide performance benefits to groups, and through qualitative analyses links these performance benefits to group processes. Second, observed uses are grounded in an established process model, and used to identify collaborative activities that are supported by personal and shared devices. Third, equity of participation on shared displays is found to positively correlate ($p = 0.028$), and equity of participation on personal displays is found to negatively correlate ($p = 0.01$) with group performance for sensemaking tasks. Fourth, the method for studying group process and performance based on teamwork and taskwork provides a useful foundation for future studies of collaborative work.

The emergence of pervasive computing power and networking infrastructure is enabling new applications. Still, many milestones need to be reached before pervasive computing becomes an integral part of our lives. An important missing piece is the middleware that allows developers to easily create interesting pervasive computing applications. This dissertation explores the middleware needs of distributed pervasive applications. The main contributions of this thesis are the design, implementation, and evaluation of two systems: D-Stampede and Crest. D-Stampede allows pervasive applications to access live stream data from multiple sources using time as an index. Crest allows applications to organize historical events, and to reason about them using time, location, and identity. Together they meet the important needs of pervasive computing applications. D-Stampede supports a computational model called the thread-channel graph. The threads map to computing devices ranging from small to high-end processing elements. Channels serve as the conduits among the threads, specifically tuned to handle time-sequenced streaming data. D-Stampede allows the dynamic creation of threads and channels, and for the dynamic establishment (and removal) of the plumbing among them. The Crest system assumes a universe that consists of participation servers and event stores, supporting a set of applications. Each application consists of distributed software entities working together. The participation server helps the application entities to discover each other for interaction purposes. Application entities can generate events, store them at an event store, and correlate events. The entities can communicate with one another directly, or indirectly through the event store. We have qualitatively and quantitatively evaluated D-Stampede and Crest. The qualitative aspect refers to the ease of programming afforded by our programming abstractions for pervasive applications. The quantitative aspect measures the cost of the API calls, and the performance of an application pipeline that uses the systems.

Mobile communication is very mature today due to the powerful computation and communication capabilities of mobile devices, the flourishing of mobile networks, the popularity of electronic commerce, and the completeness of e-payment mechanisms. It is a pleasure for mobile users to roam around the mobile networks and enjoy the mobile network services. However, there are a lot of security threats in the mobile networks, and thus we need an anonymous mutual authentication and key exchange scheme to guarantee the security and privacy for mobile users in the networks. A payment protocol is also required for charging the mobile users after using the mobile services. However, the existing payment schemes do not support anonymity and credit-based chargeability at the same time. In this dissertation, we propose a secure authentication scheme such that the mobile users can be anonymously authenticated by the system and the system can still make correct charge to these anonymous mobile users via a credit-based way simultaneously. We also propose a novel e-cash scheme which can support each mobile user to withdraw a generic e-cash and decide to spend it as an on-line e-cash or an off-line e-cash according to the payment requirement of the anonymous authentication scheme. Our proposed schemes are convenient and flexible for the mobile users, the system operator, and the bank. Besides, full privacy can be achieved for mobile users owing to the combination of our proposed schemes, which can be performed in current mobile devices efficiently with few battery energy consumptions. Furthermore, we provide anonymity control, no swindling, tamper resistance, secure mutual authentication, secure key exchange, and secure forward secrecy in the proposed anonymous authentication scheme and the e-cash scheme, where these security features are demonstrated by formal security models and theoretical proofs.

In the last decade, with the extensive use of mobile electronic and wireless communication devices, there is a growing need for context aware applications and many pervasive computing applications have become integral parts of our daily lives. Context aware recommender systems are one of the popular ones in this area. Such systems surround the users and integrate with the environment / hence, they are aware of the users&#039 / context and use that information to deliver personalized recommendations about everyday tasks. In this manner, predicting user&rsquo / s next activity preferences with high accuracy improves the personalized service quality of context aware recommender systems and naturally provides user satisfaction. Predicting activities of people is useful and the studies on this issue in ubiquitous environment are considerably insufficient. Thus, this thesis proposes an activity prediction model to forecast a user&rsquo / s next activity preference using past preferences of the user in certain contexts and current contexts of user in ubiquitous environment. The proposed model presents a new approach for activity prediction by taking advantage of ontology. A prototype application is implemented to demonstrate the applicability of this proposed model and the obtained outputs of a sample case on this application revealed that the proposed model can reasonably predict the next activities of the users.

<p><p>Context represents any information regarding the situation of entities, being these a person, place or object that is considered relevant to the interaction between a user and an application.</p><p><p>The results obtained permits an user to save context information attached to a picture in a database, as well as retrieve pictures from that database and show it in a web interface with its context information associated. The web interface also allows the user to perform searches by using different criteria, so only the pictures that matches with that criteria will be shown.</p></p></p> / Final Degree Project - Thesis

The purpose of this study was to examine a ubiquitous/pervasive computing initiative from a Community of Practice perspective. It sought to understand how faculty fit technology use into the already paramount goals they had for their students learning, and how that technology’s role became a part of that essential domain. Furthermore, it sought to determine the extent to which a community of practice emerged around the use of technology as a central practice. Using case study methodology with mixed-methods data collection strategies, this study explored practice among faculty participating in a ubiquitous laptop initiative within a pre-kindergarten through fourth-grade teacher preparation program. This program was part of a college of education in a major research university in the southern United States. Doing so involved an examination of the roles of participants, primarily faculty, in the community or communities to identify the primary domains of concern, and to determine to what extent the use of laptops in the classroom has itself become a practice around which a community has emerged. Findings from this study suggested that instructors were, to varying extents, involved in an emerging community of practice that included the use of technology, specifically laptops, to enhance the development of elementary school teachers. This community of practice was heavily dependent upon infrastructure provided by the administration of the college and the ubiquitous laptop initiative. At the same time, these instructors were less involved with a domain that included teaching teachers to use technology, or Technological Pedagogical Content Knowledge (Mishra & Koehler, 2006). / text

In the future, computers will be virtually everywhere: carried by everyone and integrated into the environment. The increased computation and communication capabilities will enable intelligent environments that react to occupants through automated decision-making. Devices (sensors and actuators) are the key to making intelligent environments a reality. We believe that devices must be made more approachable for average users. Existing approaches to application development for intelligent environments require detailed knowledge about devices and their low-leveling programming interfaces, which greatly limits the number of potential users. Instead of limiting users, we must enable everyone to program the devices around them. Intelligent environments will not be commonplace until average people can set up and manage the hardware and software necessary for their personalized applications. In simplifying the programming of intelligent environments, we first made sensors and actuators accessible to average programmers then extended our work to end-users. We term the former contribution Sensor Enablement for Average Programmers (SEAP); the latter work is Sensor Enablement for End-Users (SEEU). In our experience, devices’ disparate, niche programming languages and communication protocols presented great difficulty in developing intelligent environments. To ease the development effort for average programmers, we abstracted and standardized complex sensor and actuator interactions, allowing users to instead think in terms of well-understood web applications. Users have said that SEAP is easy-to-use and exciting. But what about average people, end-users? We found that end-users are incredibly interested in intelligent environments. By engaging end-users we can create intelligent environments even faster and allow domain experts to tailor their environment. This dissertation’s second contribution, Sensor Enablement for End-Users (SEEU) provides a visual programming interface that allows users to create personalized automated behaviors given available devices and data. We performed several user studies to uncover people’s desires for intelligent environments and determine the best interface for managing an intelligent environment. SEEU combines an intuitive interface with the power and flexibility of SEAP. SEEU is a usable end-user programming framework that allows average people to create useful applications for their intelligent environments. With SEEU and SEAP, we simplified the development of intelligent environments, reducing barriers to adoption of emerging sensing and actuation technologies. We demonstrated the feasability with a series of user studies. / text

Depuis la dernière décennie, les outils technologiques et informatiques ont connu un essor considérable dans plusieurs sphères d’activité de la société. L’éducation n’y a pas échappé, et le ministère de l’Éducation, du Loisir et du Sport (MELS) en a d’ailleurs fait une compétence transversale dans le cadre du Programme de formation de l’école québécoise. L’intégration des TIC s’est faite à travers différents moyens, à commencer par les laboratoires informatiques, les ordinateurs à même la salle de classe et, plus récemment, par l’introduction de projets portables où chaque élève et l’enseignant disposent de leur propre ordinateur. Afin d’être mené à terme, ce projet de recherche a été inscrit dans un projet à plus grande échelle, soit celui d’une recherche financée par le Conseil de recherches en sciences humaines du Canada (CRSH), qui a pour objectif d'analyser les obstacles auxquels font face les enseignants dans l'intégration des technologies à l'école. Le présent projet s'est quant à lui attardé plus spécifiquement aux défis technologiques et pédagogiques inhérents aux projets portables. L’étude s'est déroulée en milieu défavorisé, dans une école primaire montréalaise. Une telle intégration demande une planification rigoureuse et un suivi continu afin d’assurer le succès du projet. De plus, il est évident que ce type de projet pose aussi des défis technologiques et pédagogiques particuliers pour les enseignants. À ce sujet, trois catégories de facteurs qui peuvent avoir un impact sur la réussite des projets portables ont été relevées, soit : les facteurs personnels (internes à l’enseignant), les facteurs relatifs au travail (contexte d'enseignement, pratiques pédagogiques, etc.), ainsi que les facteurs relatifs au matériel et à l’infrastructure. À l’intérieur de ce mémoire, différents concepts, dimensions et indicateurs sont donc explicités et mis en relation afin de mieux comprendre les défis technologiques et pédagogiques qui peuvent survenir dans le cadre de la mise en oeuvre de projets portables. Trois enseignantes rattachées à autant de groupes d’élèves ont accepté de participer à une entrevue individuelle et de répondre à un questionnaire. Les échanges par courriel ont aussi été analysés. L'ensemble des données recueillies ont fait l'objet d'analyses qualitatives. Les analyses ont montré que la catégorie de facteurs citée la plus fréquemment était celle des facteurs relatifs au travail avec une forte majorité. Des défis ont toutefois été identifiés pour toutes les dimensions. / During the past decade, the presence of ICT and technology in general has increased significantly in many areas of society. Education was no exception, and MELS has even created a transversal competency for that matter under the Programme de formation de l'école québécoise. ICT integration was made through various means, including computer labs, computers in the classroom and, more recently, by the introduction of ubiquitous computing projects, in which each student and the teacher have their own computer. In order to complete this research project successfully, it has been included within a broader project subsidized by the Social Sciences and Humanities Research Council of Canada. This project is taking place in a disadvantaged community elementary school of Montreal. Ubiquitous computing asks for rigourous planning and ongoing follow-up by teachers, administrative and IT staff. Moreover, such a project obviously presents some technical and pedagogical challenges for teachers. Regarding this matter, three major categories of factors that can impact success of ubiquitous computing projects in education were identified. Those categories can be described as follows : factors that are internal to the teacher (personal matter), factors that are related to work, as well as factors related to infrastructure and equipment. Several concepts, dimensions and indicators are explained in this paper and correlated in order to better understand the challenges that can arise in such projects. Regarding the methodoly used in this research, three teachers accepted to participate in individual interviews, and also answered an online questionnaire. Furthermore, the e-mails exchanged between the research group and the teachers were also analyzed. All data coming from those three sources was subject to a qualitative analysis. The data analysis showed that the dominating category of factors was the one with factors related to work, by a vast majority. Challenges, however, were identified for all dimensions and categories.

To provide users with personalized adaptive services only using the accessible computing resources in a cloud environment, context aware applications need to assimilate both the accessed and derived context, i.e. a combination of more than one sensed data and information in the environment. Context data dependency, dependency that arises between the context data producer and consumer, may get introduced in a system due to numerous reasons. But as the number of context dependencies for a service increases, the more complex the system becomes to manage. The thesis addresses issues of how to identify context dependencies, represent such context dependencies and then reduce them in a system. In the first part of the thesis, we present two efficient approaches to determine context dependency relations among various services in ubiquitous computing environment to help better analyse the pervasive services. One approach is based on graph theory, and we have used the topological sort to determine the context dependencies. The second approach is based on solving constraint networks which determines whether an entity is affected when the state of a certain other entity has its state changed, i.e. determining the dynamic nature of context dependency. In the second part of the thesis, we present a mode for representation of context dependencies within a system. Our model that represents context dependencies is based on set theory and first-order predicate logic. The context dependency representation model also represents alternative sources for context acquisition that can be utilized in a case in which the preferred context producers are not available to service the desired context to the relevant context consumer any more. Further, we try to reduce the context dependencies by presenting the idea of profile context, which is based on the proposal of an open framework for context acquisition, management and distribution. This heuristic approach is based on the idea of utilizing mobile nodes in an ad hoc overlay network with more resources than the context producer itself to store various contextual information under the banner of profile context, and further, provide profile context instead of each context individually based on the queries the nodes receive from the context consumers. Bringing together the context information and context updates from various sources, support for context aware decisions can be implemented efficiently in a mobile environment by addressing the issues of context dependency using profile context

Le déploiement de logiciels répartis dans des environnements à grande échelle et ouverts (tels les systèmes ubiquitaires, les systèmes mobiles et les systèmes P2P) est une problématique actuelle ouverte. Ces environnements sont distribués, hétérogènes et peuvent être de nature instable (dotés d'une topologie dynamique du réseau). Le déploiement dans ces environnements met en jeu un très grand nombre de machines, de liens réseau ainsi qu'un ensemble de contraintes de déploiement. Quelques solutions de déploiement existent aujourd'hui, mais ne sont exploitables que dans le cadre d'architectures figées et fiables. Dans la plupart des solutions, une personne en charge du déploiement doit décrire plus ou moins manuellement la topologie. En outre, la majorité de ces outils ne prennent pas en compte les problèmes dûs à la variabilité de la qualité de service du réseau, aux pannes des hôtes, aux défaillances des liens du réseau ou encore aux changements dynamiques de topologie, qui caractérisent les environnements ouverts. Dans ce mémoire, nous présentons les motivations de la réalisation d'une infrastructure de déploiement logiciel autonomique et les exigences sous-jacentes d'une telle plate-forme. Nous présentons un état de l'art du déploiement logiciel que nous analysons au regard du contexte visé. Ensuite, nous présentons notre contribution pour le déploiement autonomique. Notre proposition s'appuie sur une combinaison de technologies (composants logiciels, agents mobiles adaptables, intergiciel, langage dédié). Nous proposons j-ASD, un intergiciel qui exploite la complémentarité de ces technologies pour réaliser un déploiement logiciel autonomique. Le processus de déploiement contient trois étapes : description des contraintes de déploiement, résolution, et déploiement autonomique. Pour la première étape, nous avons défini un langage dédié (DSL) comme langage de haut niveau pour exprimer des contraintes de déploiement. Pour la deuxième, nous avons conçu une infrastructure répartie pour collecter les propriétés des sites cibles, ce qui permet de résoudre les contraintes de déploiement. Pour la troisième étape, nous proposons un intergiciel à base d'agents mobiles pour la réalisation et la supervision du déploiement autonomique. Enfin, nous donnons les éléments de conception du prototype que nous avons implémenté, ainsi que les résultats de certaines expérimentations pour montrer la validité de notre approche