Context-aware applications must manage a continuous stream of context according to dedicated business logic. Research was limited on proposing frameworks and platforms that have predefined behavior toward applications. This thesis attempts to extend background works by proposing new concepts serving as foundation for a flexible approach for building context-aware applications. The thesis examines the state of the art of context-aware computing, then adopts well-established software design principles and a functional decomposition for designing a reference model for context management enabling seamless integration of context-awareness into applications. Also, the thesis studies the use of context in common applications and proposes a context-centric modeling approach which allows the creation of a graph-based representation where entities are connected to each other through links representing context. Furthermore, the context graph decouples the presentation and the semantics of context, leaving each application to manage the appropriate semantic for their context data. Case studies are conducted for the evaluation of the proposed system in terms of its support for the creation of applications enhanced with context-awareness. A simulation study is performed to analyze the performance properties of the proposed system. The result of this thesis is the introduction of a novel approach for supporting the creation of context-aware applications that supports the integration of context-awareness to existing applications. It empowers developers as well as users to participate in the creation process, thereby reducing usability issues

Up to now various recommendation systems have been proposed for web based applications such as e-commerce and information retrieval where a large amount of product or information is available. Basically, the task of the recommendation systems in those applications, for example the e-commerce, is to find and recommend the most relevant items to users/customers. In this domain, the most prominent approaches are collaborative filtering and content-based filtering. Sometimes these approaches are called as user profiling as well. In this work, a context-aware recommendation system is proposed for mobile environment, which also can be considered as an extension of those recommendation systems proposed for web-based information retrieval and e-commerce applications. In the web-based information retrieval and e-commerce applications, for example in an online book store (e-commerce), the users&amp / #8217 / actions are independent of their instant context (location, time&amp / #8230 / etc). But as for mobile environment, the users&amp / #8217 / actions are strictly dependent on their instant context. These dependencies give raise to need of filtering items/actions with respect to the users&amp / #8217 / instant context. In this thesis, an approach coupling approaches from two different domains, one is the mobile environment and other is the web, is proposed. Hence, it will be possible to separate whole approach into two phases: context-aware prediction and user profiling. In the first phase, combination of two methods called fuzzy c-means clustering and learning automata will be used to predict the mobile user&amp / #8217 / s motions in context space beforehand. This provides elimination of a large amount of items placed in the context space. In the second phase, hierarchical fuzzy clustering for users profiling will be used to determine the best recommendation among the remaining items.

L’ étude de la littérature montre que la sensibilité au contexte est devenue un élément primordial pourla mise en place des services adaptatifs dans les applications interactives pervasives. Le contexten’est plus un modéle préétabli et prédéfini au moment de la conception des systèmes des applicationsinteractives mais plutôt une description dynamique des situations courantes qui peuvent êtredécouvertes dans les données de contexte et qui peuvent changer dynamiquement en fonction deschangements des exigences et des préférences des utilisateurs. Les applications pervasives doiventpouvoir s’exécuter dans différents contextes d’utilisation selon l’environnement de l’utilisateur, sonprofil, le terminal qu’il utilise, sa localisation, . . . Afin de répondre aux différentes exigences d’adaptationaux changements dynamiques des situations contextuelles, nous proposons des m´ecanismespermettant de fournir la trac¸abilitéde contexte sous la forme de Cartes de Visite COntextuelles(CVCO). Ces mécanismes s’appuient sur la technique de Mapping OWL afin de donner des modèlesontologiques de trac¸abilité de contexte. Les différentes ontologies créées pendant ce travail sontintégrées au sein de l’architecture de notre nouvelle plateforme d’adaptation de contexte COALA(COntext Adaptation Platform), afin de permettre l’adaptation automatique des services offerts parles application interactives pervasives. Ces travaux ont été r éalis ´es et appliqu éés dans le cadre d’unethèse en co-tutelle entre la Tunisie et France. / The study of the literature proves that context-awareness has become a key element for the implementationof adaptive services in pervasive interactive applications. In fact, the present work focuseson the context of modeling issues for the adaptation of services provided by the invective pervasiveapplications to the sensitivity of context situations. The context is no longer a pre-established and predefinedtemplate when designing interactive applications systems but rather a dynamic description ofthe common situations that can be discovered in the context data and can dynamically be changedwhen changing user’s requirements and preferences. The systems of pervasive applications must beavailable in different contexts of use according to the user’s environment, the terminal being used, location. . .. The major challenge of these systems accordingly relates to the adaptation of the servicesoffered by interactive applications to the user context. In Order to respond to different requirementsof dynamic adaptation to changes in contextual situations, following the changes in usage patternsas well as the dynamics of the pervasive environment and the heterogeneity of context data sources,we propose mechanisms used to provide the traceability of the context as Virtual contextual Cards(VCOC). These works were carried out and applied as part a PhD under joint supervision betweenTunisia and France.

Förstärkt verklighet eller Augmented Reality (AR) är idag en av de viktigaste riktningarna inom informationsteknologiområdet (IT). AR-tekniken har redan använts inom områden såsom underhållning, konstruktion, medicinsk behandling, utbildning och är tillgänglig i flera olika enheter som till exempel mobiltelefoner, surfplattor, etcetera. Under de senaste åren har allt snabbare framsteg gjorts inom mobilapplikationer som erbjuder AR-upplevelser, men det finns fortfarande ett behov av en djupare förståelse för hur en bättre användarupplevelse eller User Experience (UX) kan designas i dessa Augmented Reality Mobile Applications (ARMA). Detta examensarbete fokuserar på de aspekter av interaktionen som måste beaktas när ett grafiskt användargränssnitt baserat på ARMA utformas i syfte att göra applikationerna kontextkänsliga. Det betyder att hjälpa användaren få relevant information som passar situationen eller den kontext denne befinner sig in när hen använder sin mobiltelefon och därmed erbjuda hen bättre användarupplevelser. Studien omfattar en heuristisk utvärdering och ett användbarhetstest av mobilapplikationen Layar som bland annat känner igen olika Points of Interest (POI) och som ger direkt digital kontextuell information om dem. Baserat på resultatet av den heuristiska utvärderingen och användbarhetstestet i kombination med tidigare forskning inom området, har åtta stycken designriktlinjer tagits fram. Jag hoppas att dessa riktlinjer kan fungera som ett stöd vid utformningen av gränssnittet på kontextkänsliga ARMA och i förlängningen förbättra användarupplevelsen.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / In ubiquitous systems, due to the complexity added by the use of contextual information, the application of context aware exception handling (CAEH) techniques has many challenges and in the literature several approaches have been found to define concepts and abstractions useful for modeling CAEH. However, only one of these approaches proposes a method for specification and verification of models in the field of ubiquitous systems, which provides a tool for specifying the CAEH model using a Java API, and also generates an error report to a text file. The disadvantage of this approach is that the designer should strive to understand programming details that are irrelevant to the analysis process of the exceptional behavior of the system. Then, this work aims to propose a domain specific language for modeling CAEH, which provides abstractions and constructors that allow to express relevant concepts and make the task of designing CAEH models simpler and more intuitive. In addition, the language is integrated with the tool mentioned before that allows automatic model verification. The errors generated by the verifier are now shown directly in the source code making their identification and correction easier for the designer. In order to evaluate the language, a case study is conducted to provide evidence of its viability as an alternative to modeling CAEH. / Em sistemas ubÃquos, devido à complexidade inserida pela utilizaÃÃo de informaÃÃes contextuais, a aplicaÃÃo de tÃcnicas de tratamento de exceÃÃo sensÃvel ao contexto (TESC) tem sido objeto de estudo para muitos pesquisadores. Na literatura sÃo encontradas diversas abordagens que definem conceitos e abstraÃÃes Ãteis para modelagem de TESC. Entretanto, apenas uma dessas abordagens propÃe um mÃtodo para especificaÃÃo e verificaÃÃo de modelos no domÃnio de sistemas ubÃquos o qual fornece uma ferramenta para especificaÃÃo do modelo de TESC atravÃs de uma API Java, e gera ainda um relatÃrio de erros em um arquivo texto. A desvantagem dessa abordagem à que o projetista deve se esforÃar para entender detalhes de programaÃÃo irrelevantes ao processo de anÃlise do comportamento excepcional do sistema. Esta dissertaÃÃo tem portanto como objetivo propor uma linguagem de domÃnio especÃfico para modelagem de TESC, com o intuito de oferecer abstraÃÃes e construtores que permitem expressar conceitos pertinentes e tornar a tarefa de projetar modelos de TESC mais simples e intuitiva. AlÃm disso, a linguagem à integrada com a ferramenta citada anteriormente, o que permite realizar a verificaÃÃo do modelo de forma automÃtica. Os erros gerados pelo verificador sÃo mostrados agora diretamente no cÃdigo do modelo facilitando a identificaÃÃo e correÃÃo dos mesmos pelo projetista. A fim de avaliar a linguagem, um estudo de caso à realizado para fornecer indÃcios de sua viabilidade como alternativa para modelagem de TESC.

Made available in DSpace on 2018-06-27T18:56:27Z (GMT). No. of bitstreams: 3 Jonas Bulegon Gassen.pdf: 799149 bytes, checksum: 2d5d71d3a957faa5f82feebbf14e88fc (MD5) Jonas Bulegon Gassen.pdf.txt: 183193 bytes, checksum: ac769c0da06ca7ce3b8154b94c90eaf6 (MD5) Jonas Bulegon Gassen.pdf.jpg: 3509 bytes, checksum: dfc698f4611f3e08f6acfc0f11a92b31 (MD5) Previous issue date: 2010-03-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / For a hospital environment can be called as "pervasive", it requires that all the entities that are present in this context (like people and equipment) are sinchronized to perform the daily common tasks. Inside these environments, the computational devices should be considered tools to access information and, therefore, they shouldn't be the focus of attention of the professional. Thus, they should be used naturally. For the system to behave in such a way, it is necessary that it adapts itself to the users contexts. One of the most indicated ways to represent these contexts is through ontologies, due to the great expressivity that they allow. However, environments such as proposed require an extremely dynamic system to represent the context in a coherent manner with the changes in this environment, because their professionals encounter a frequent changing of shifts and tasks in which they work with diferent patients and information from diferent sources. To this end, this dissertation proposes an architecture for a hospital pervasive that seeks to provide all the features mentioned above. / Para que um ambiente hospitalar possa vir a tornar-se pervasivo, necessita-se que as entidades presentes neste contexto (como pessoas e equipamentos) estejam em perfeita sincronia para a realização das tarefas comuns do dia-a-dia. Dentro destes ambientes, os dispositivos computacionais devem ser considerados ferramentas para o acesso à informação e, portanto, não devem ser foco de atenção dos profissionais. Desta forma, os mesmos devem ser utilizados de forma natural. Para que o sistema possa se comportar de tal forma, é necessário que o mesmo se adapte ao contexto dos usuários. Uma das maneiras mais indicadas para efetuar a representação destes contextos é através de ontologias, devido a grande expressividade que estas permitem. Entretanto, ambientes como o proposto necessitam de um sistema extremamente dinâmico para representar o contexto de forma coerente com as modificações ocorridas neste ambiente, pois seus profissionais contam com uma freqüente modificação de turnos e tarefas, onde os mesmos trabalham com diferentes pacientes e informações provenientes de diferentes fontes. Para tal, esta dissertação propõe uma arquitetura para um ambiente hospitalar pervasivo que busca prover todas as funcionalidades acima citadas.

Notre travail concerne les systèmes d’aide à la visite de musée et l’accès au patrimoine culturel. L’objectif est de concevoir des systèmes de recommandation, implémentés sur dispositifs mobiles, pour améliorer l’expérience du visiteur, en lui recommandant les items les plus pertinents et en l’aidant à personnaliser son parcours. Nous considérons essentiellement deux terrains d’application : la visite de musées et le tourisme. Nous proposons une approche de recommandation hybride et sensible au contexte qui utilise trois méthodes différentes : démographique, sémantique et collaborative. Chaque méthode est adaptée à une étape spécifique de la visite de musée. L’approche démographique est tout d’abord utilisée afin de résoudre le problème du démarrage à froid. L’approche sémantique est ensuite activée pour recommander à l’utilisateur des œuvres sémantiquement proches de celles qu’il a appréciées. Enfin l’approche collaborative est utilisée pour recommander à l’utilisateur des œuvres que les utilisateurs qui lui sont similaires ont aimées. La prise en compte du contexte de l’utilisateur se fait à l’aide d’un post-filtrage contextuel, qui permet la génération d’un parcours personnalisé dépendant des œuvres qui ont été recommandées et qui prend en compte des informations contextuelles de l’utilisateur à savoir : l’environnement physique, la localisation ainsi que le temps de visite. Dans le domaine du tourisme, les points d’intérêt à recommander peuvent être de différents types (monument, parc, musée, etc.). La nature hétérogène de ces points d’intérêt nous a poussé à proposer un système de recommandation composite. Chaque recommandation est une liste de points d’intérêt, organisés sous forme de packages, pouvant constituer un parcours de l’utilisateur. L’objectif est alors de recommander les Top-k packages parmi ceux qui satisfont les contraintes de l’utilisateur (temps et coût de visite par exemple). Nous définissons une fonction de score qui évalue la qualité d’un package suivant trois critères : l’appréciation estimée de l’utilisateur, la popularité des points d’intérêt ainsi que la diversité du package et nous proposons un algorithme inspiré de la recherche composite pour construire la liste des packages recommandés. L’évaluation expérimentale du système que nous avons proposé, en utilisant un data-set réel extrait de Tripadvisor démontre sa qualité et sa capacité à améliorer à la fois la précision et la diversité des recommandations. / Our work concerns systems that help users during museum visits and access to cultural heritage. Our goal is to design recommender systems, implemented in mobile devices to improve the experience of the visitor, by recommending him the most relevant items and helping him to personalize the tour he makes. We consider two mainly domains of application : museum visits and tourism. We propose a context-aware hybrid recommender system which uses three different methods : demographic, semantic and collaborative. Every method is adapted to a specific step of the museum tour. First, the demographic approach is used to solve the problem of the cold start. The semantic approach is then activated to recommend to the user artworks that are semantically related to those that the user appreciated. Finally, the collaborative approach is used to recommend to the user artworks that users with similar preferences have appreciated. We used a contextual post filtering to generate personalized museum routes depending on artworks which were recommended and contextual information of the user namely : the physical environment, the location as well as the duration of the visit. In the tourism field, the items to be recommended can be of various types (monuments, parks, museums, etc.). Because of the heterogeneous nature of these points of interest, we proposed a composite recommender system. Every recommendation is a list of points of interest that are organized in a package, where each package may constitute a tour for the user. The objective is to recommend the Top-k packages among those who satisfy the constraints of the user (time, cost, etc.). We define a scoring function which estimates the quality of a package according to three criteria : the estimated appreciation of the user, the popularity of points of interest as well as the diversity of packages. We propose an algorithm inspired by composite retrieval to build the list of recommended packages. The experimental evaluation of the system we proposed using a real world data set crawled from Tripadvisor demonstrates its quality and its ability to improve both the relevance and the diversity of recommendations.

Philosophiae Doctor - PhD / This research study investigates optimization of IRS to individual information needs in order of relevance. The research addressed development of algorithms that optimize the ranking of documents retrieved from IRS. In this thesis, we present two aspects of context-awareness in IR. Firstly, the design of context of information. The context of a query determines retrieved information relevance. Thus, executing the same query in diverse contexts often leads to diverse result rankings. Secondly, the relevant context aspects should be incorporated in a way that supports the knowledge domain representing users’ interests. In this thesis, the use of evolutionary algorithms is incorporated to improve the effectiveness of IRS. A context-based information retrieval system is developed whose retrieval effectiveness is evaluated using precision and recall metrics. The results demonstrate how to use attributes from user interaction behaviour to improve the IR effectiveness

Vývoj v informačním systému neustále zvyšuje nároky na účinnou, efektivní a adaptivní spolupráci mezi komponenty systému, aby se vyrovnal se změnami v systému a zaručil tak nejlepší výkon. K dosažení těchto požadavků byly zavedeny dva hlavní přístupy. Přístup k adaptaci umožňuje informačnímu systému přizpůsobit se změnám v kontextu informací systému a jeho okolního prostředí na základě adaptační strategie. Přístup ke zvyšování informovanosti zase napomáhá sledovat informace o kontextu a rozpoznat změny, které mohou proces adaptace vyvolat. V této práci představujeme obecný kontextově orientovaný model vlastní adaptivní architektury pro podporu softwarového systému s adaptačními funkcemi, které zaručují dostupnost systému, provozní podmínky a výkon. Navíc poskytujeme dvě případové studie v reálném životě jako důkaz konceptu použitelnosti našeho navrhovaného adaptačního přístupu.

Context awareness is an important aspect of pervasive and ubiquitous computing. By utilizing contextual information gathered from the environment, applications can adapt to the user’s specific situation. In this thesis, user context is used to automatically discover multimedia devices and services that can be used by a mobile Session Initiation Protocol (SIP) user agent. The location of the user is captured using various sensing technologies to allow users of our SIP user agent to interact with network attached projectors, speakers, and cameras in a home or office environment. In order to determine the location of the user, we have developed and evaluated a context aggregation framework that gathers and analyzes contextual information from various sources such as passive infrared sensors, infrared beacons, light intensity, and temperature sensors. Once the location of the user is determined, the Service Location Protocol (SLP) is used to search for services. For this purpose, we have implemented a mobile SLP user agent and integrated it with an existing SIP user agent. The resulting mobile SIP user agent is able to dynamically utilize multimedia devices around it without requiring the user to do any manual configuration. This thesis also addressed the challenge of building trust relationship between the user agent and the multimedia services. We propose a mechanism which enables the user agent authenticate service advertisements before starting to redirect media streams. The measurements we have performed indicate that the proposed context aggregation framework provides more accurate location determination when additional sensors are incorporated. Furthermore, the performance measurements indicate that the delay incurred by introducing context awareness to the SIP user agent is acceptable for a small deployment such as home and office environment. In order to realize large scale deployments, future investigations are recommended to further improve the performance of the framework. / Att vara medveten om kontexten är en viktig synpunkt av präglande och allestädes närvarande uppskattning av omgivningen. Genom att utnyttja den kontextuella informationen som samlats in från omgivningen, kan applikationen anpassas till användarens specifika situation. I denna avhandling använder man användarens sammanhang för att automatiskt upptäcka multimedia utrustning och tjänster som kan användas av en mobil Session Initiation Protokoll (SIP) användaragent. Placeringen av användaren mäter man med hjälp av olika sensorer för att låta användare av vår SIP användaragent att interagera med nätverk tillkopplat projektorer, högtalare och kameror i hem eller kontorsmiljöer. För att avgöra var användaren befinner har vi utvecklat och utvärderat en sammanhangsstruktur som samlar in och analyserar innehållsbaserad information från olika källor; passiva infraröda sensorer, infraröd beacons, ljusstyrkan och temperaturgivare. Efter bestämmaning användarens placering den så kallade Service Location Protocol (SLP) användas för att söka efter tjänster. För detta ändamål har vi genomfört en mobil SLP användaragent och integrerat denna med ett befintligt SIP användaragent. Den resulterande i mobil SIP användaragent som dynamiskt kan utnyttja multimedia utrustning runt omkring utan att kräva att användaren skall kunna göra någon manuell konfiguration. Avhandlingen tar även upp den utmaningen som krävs för att bygga förtroende mellan användaragenten och multimedia tjänster. Vi föreslår en mekanism som gör det möjligt för användaragenten att verifiera tjänstannonsering innan man börjar dirigera medieströmmar. Dessutom så indikerar mätningarna av prestanda att fördröjningen som man utsätter den för genom att introducera ”medvetenhet om sammanhanget” till SIP användaragenten är acceptabel på hemma eller i en företagsmiljö. För att stora spridningar skall bli verklighet så rekommenderas det att göra mer forskning för att förbättra prestanda.