Context-aware systems use context information to decide what adaptation actions to perform in response to changes in their environment. Depending on applications, context information includes physical context (e.g. temperature and location), user context (e.g. user preferences and user activity), and ICT context (e.g. device capabilities and battery power). Sensors are the main mean of capturing context. Unfortunately, sensed context data are commonly prone to imperfection due to the technical limitations of sensors, their availability, dysfunction, and the highly dynamic nature of environment. Consequently, sensed context data might be imprecise, erroneous, conflicting, or simply missing. To limit the impact of context imperfection on the behavior of a context-aware system, a notion of Quality of Context (QoC) is used to measure quality of any information that is used as context information. Adaptation is performed only if the context data used in the decision-making has an appropriate quality level. This thesis conducts a novel framework for QoC in context-aware systems, which is called MCFQoC (Multilayered-Context Framework for Quality of Context). The main innovative features of our framework, MCFQoC, include: (1) a new definition that generalizes the notion of QoC to encompass sensed context as well as user profiled context; (2) a novel multilayer context model, that distinguishes between three context abstractions: context situation, context object, and context element in descending order. A context element represents a single value and many context elements can be compound into a context object. Many context objects in turn form a context situation; (3) a novel model of QoC parameters which extends the existing parameters with new quality parameter and explicitly distributes the quality parameters across the three layers of context abstraction; (4) a novel algorithm, RCCAR (Resolving Context Conflicts Using Association Rules), which has been developed to resolve conflicts in context data using the Association Rules (AR) technique; (5) a novel mechanism to define QoC policy by assigning weights to QoC parameters using a multi-criteria decision-making technique called Analytical Hierarchy Process (AHP); (6) and finally, a novel quality control algorithm called IPQP (Integrating Prediction with Quality of context Parameters for Context Quality Control) for handling context conflicts, context missing values, and context erroneous values. IPQP is extension of RCCAR. Our framework, MCFQoC, has been implemented in MatLab and evaluated using a case study of a flood forecast system. Results show that the framework is expressive and modular, thanks to the multilayer context model and also to the notion QoC policy which enables us to assign weights for QoC’s parameters depending on quality requirements of each specific application. This flexibility makes it easy to apply our approach to a wider type of context-aware applications. As a part of MCFQoC framework, IPQP algorithm has been successfully tested and evaluated for QoC control using a variety of scenarios. The algorithm RCCAR has been tested and evaluated either individually and as a part of MCFQoC framework with a significant performance concerning resolving context conflicts. In addition, RCCAR has achieved a good success comparing to traditional prediction methods such as moving average (MA), weighted moving average, exponential smoothing, doubled exponential smoothing, and autoregressive moving average (ARMA).

L'informatique sensible au contexte vise à réduire la quantité d'informations explicites qu'un utilisateur doit fournir pour que le système accomplisse la tâche souhaitée. Ceci est particulièrement vrai dans le domaine récent de l'intelligence ambiante où les objets de la vie courante deviennent capables de déclencher une action ou un échange spontané d'informations, sans interaction avec l'utilisateur. Les progrès techniques en matière de réseaux de communication sans fil, d'équipements mobiles individuels, de capteurs et de logiciels embarqués, rendent aujourd'hui possibles des services aux usagers dépendants du contexte, mais les applications concrètes demeurent encore très limitées. Les travaux existants dans la littérature décomposent la gestion de contexte en quatre fonctionnalités: la collecte, l'interprétation, la détection de situations et l'utilisation pour l'adaptation. L'élément discriminant des solutions existantes est la qualité des informations abstraites obtenues par inférence et devant caractériser les situations de l'utilisateur. Les limites de ces solutions sont le manque de composition aisée des informations de contexte, le passage à l'échelle, tant en termes de quantité d'informations de contexte que de nombre d'applications clientes, l'absence de garantie sur la cohérence et la qualité des informations de contexte, et le manque de solutions intergicielles permettant de libérer le concepteur d'applications des aspects liés à la gestion de contexte. Nous nous intéressons dans cette thèse à la gestion de la qualité de contexte (QoC) dans un environnement ambiant. Les problématiques de gestion de la qualité de contexte sont multiples: choisir la méthode adéquate pour la gestion du contexte, extraire la qualité associée au contexte, interpréter et analyser la qualité de contexte pour les applications sensibles au contexte. Nous proposons de répondre à ces problématiques en intégrant la qualité de contexte au sein de la plateforme de gestion de contexte COSMOS (http://picoforge.lntevrv.fr/proiects/svn/cosmos) de l'équipe MARGE (http://www-inf.itsudparis.eu/MARGE) de Télécom SudParis. Afin d'effectuer cette intégration, nous avons conçu des éléments spécifiques à la qualité de contexte et avons mis en place une gestion fine et efficiente de cette qualité en limitant le surcoût associé. Nous proposons également un processus de conception basé sur l'ingénierie dirigée par les modèles afin de générer les éléments requis à la gestion de la qualité de contexte. Nous avons validé nos contributions à l'aide de deux applications fonctionnant sur téléphone mobile : une application de "vente flash" dans un centre commercial et une application de détection de localisation sur un campus. Les tests de performances que nous avons effectués permettent de comparer les résultats avec et sans la prise en compte de la QoC et montrent le faible coût de la gestion de la qualité par rapport aux améliorations apportées aux applications sensibles au contexte / Context-aware computing aims to reduce the amount of explicit information required from a user for a system to perform a task. This is particularly true in the recent domain of ambient intelligence where everyday life objects are able to trigger an action or a spontaneous information exchange, without any interaction with the user. Technical advances in wireless communication, personal mobile devices, sensors and embedded software make context-aware services possible, but concrete applications are still very limited. The solutions proposed in the literature decompose context management into four functions: acquisition, interpretation, situation detection and application adaptation. The differentiating element in these proposals is the quality of the high-level context information obtained by inference and characterising the situation of the user. The limits of these solutions are the difficulty for composing context information scalability in terms of the quantity of context information and of the number of client applications, the absence of guarantee on the consistency of context information and the lack of middleware solutions able to free the designer of context-aware applications from the management of context data. In this thesis, we are interested in the management of the quality of context information (QoC) in an ambient environment. There are several key issues in QoC management: choosing the adequate method for context management, extracting the quality associated to the context, analysing and interpreting the quality of the context with regard to the requirements of context-aware applications. We propose to answer these questions by integrating QoC management into the COSMOS context management framework (http://picoforge.int-evry.fr/projects/svn/cosmos) developed by the MARGE team (http://www-inf.itsudparis.eu/MARGE) of Télécom SudParis.For this purpose, we have designed the necessary components dedicated to QoC management and we have implemented the mechanisms allowing a fine-grain manipulation of the QoC together with a limitation of the associated overhead. We also propose a design process based on model-driven engineering in order to automatically generate the elements responsible of QoC management. We validate our contributions through the development of two prototype applications running on mobile phones: a Flash sale offer application to be used in malls and a location detection application proposed to the students of a campus. The performance tests we have conducted allow to compare the results obtained with and without taking into account the QoC and show the low overhead associated to QoC manaqement with regard to the benefits brought to context-aware applications and services

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2016-08-10T13:23:57Z No. of bitstreams: 2 Dissertação - Márcio Vinicius Oliveira Sena - 2016.pdf: 1222160 bytes, checksum: ca880e6a18b3f494d8b0e578a83d6b24 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-10T13:40:14Z (GMT) No. of bitstreams: 2 Dissertação - Márcio Vinicius Oliveira Sena - 2016.pdf: 1222160 bytes, checksum: ca880e6a18b3f494d8b0e578a83d6b24 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-10T13:40:14Z (GMT). No. of bitstreams: 2 Dissertação - Márcio Vinicius Oliveira Sena - 2016.pdf: 1222160 bytes, checksum: ca880e6a18b3f494d8b0e578a83d6b24 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-05-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / More than a decade after the first training paradigm Computer Context Sensitive, the term Quality of Context (QoC) emerged in a setting filled with services that provide userapplication interactions seamlessly, highlighting the need for managers of information context. These infrastructures that handle context information, CMS (Context Management System), are full of inputs and outputs relevant data or not. The relevance of information is studied by many lines of sensitive computing the context, including QoC. Although there are a large number of QoC metrics, the literature still lacks general values to characterize the relevance of context information, ie from metrics produce an overall value that represents the importance of information. The objective of this work is to propose, from fuzzy logic, a combination of metrics in order to produce a QoC value for each information received, and possible disposal, if this information does not meet the expected relevance, described in this work by policies of QoC. In order to disseminate the context of consumers that information produced, this research proposes also, from an ontology domain independent QoC, annotate semantically the data that refer to the quality of information, thus avoiding the need for new measures in a short-term time. Finally, this paper presents the application of the solutions found in a case study of monitoring vital signs of patients in ICU. / Mais de uma década depois da primeira formulação do paradigma de Computação Sensível ao Contexto, o termo de Quality of Context (QoC) emergiu em um cenário repleto de serviços que proporcionam interações usuário-aplicação de forma transparente, evidenciando a necessidade de gerenciadores de informações de contexto. Estas infraestruturas que manipulam informações de contexto, CMS (Context Management System), estão repletas de entradas e saídas de dados relevantes ou não. A relevância das informações é objeto de estudo de muitas linhas da computação sensível a contexto, inclusive QoC. Embora haja uma infinidade de métricas de QoC, a literatura ainda carece de valores gerais para caracterizar a relevância de uma informação de contexto, ou seja, a partir de métricas, produzir um valor geral que represente a importância de uma informação. O objetivo deste trabalho é propor, a partir de Lógica Nebulosa, uma combinação de métricas, a fim de produzir um valor de QoC para cada informação recebida, sendo possível o descarte, caso essa informação não atenda a relevância esperada, descrita nesse trabalho por políticas de QoC. Buscando disseminar aos consumidores de contexto essas informações produzidas, esta pesquisa propôe também, a partir de uma ontologia de QoC independente de domínio, anotar semanticamente os dados que se referem a qualidade da informação, evitando assim a necessidade de novas medições em um prazo curto de tempo. Por fim, este trabalho apresenta a aplicação das soluções encontradas em um estudo de caso de monitoramento de sinais vitais de pacientes em UTIs.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / U -Learning environments seek to collect information about users' preferences and needs to formulate its context and make adjustments to their content and interface to suit the user's profile, whereas in traditional VLEs, such as Moodle, this profile is hardly considered. Added to this, context information that are collected are characterized by being very volatile, which increases the probability that there are inconsistencies and inaccuracies. Based on this, the Quality of Context aims to treat this information with the application of quality standards that aim to create greater assurance that the context information reflects the momentary situation of the user. This paper presents a ubiquitous virtual learning environment, in which was developed three modules and integrated with Moodle, which was used as the basis for the development of this work. Parameters and metrics for Quality of Context are applied on the information collected in the environment, so that greater assurance can be created so that the context made the environment is appropriate to the preferences and needs of the user. Adaptations to the environment are performed using the Adaptive Hypermedia, and the types of information collected are cognitive user profile and your connection speed, which are captured through SEDECA 2.0 and U -SEA 2.0, respectively modules and that also suffered a restructuring in its mode of operation. Moreover, an automatic adaptation module provides the interface to the environment of use on mobile devices. As a result, testing software and users have shown that the environment UVLEQoC operated satisfactorily, based on the assessments made by the group of people who tested the modules and their operation. The questionnaire on the SUS and the developed modules, which included the validation of the technique through Cronbach's alpha, showed results within a range considered good, which reproduces the completion of the objectives proposed in this work, even if some difficulties and problems have been identified during development. / Os ambientes U-Learning buscam coletar informações referentes às preferências e necessidades dos usuários para formular o seu contexto e realizar adaptações no seu conteúdo e interface para se adequar ao perfil do usuário, visto que em AVAs tradicionais, como o Moodle, este perfil dificilmente é considerado. Agregado a isto, as informações de contexto que são coletadas têm como característica serem muito voláteis, o que aumenta a probabilidade de existirem inconsistências e imprecisões. Com base nisso, a Qualidade do Contexto busca tratar estas informações, com a aplicação de parâmetros de qualidade que objetivam criar maiores garantias de que as informações de contexto reflitam a situação momentânea do usuário. Essa dissertação apresenta um ambiente virtual de aprendizagem ubíquo, no qual foram desenvolvidos três módulos e integrados ao Moodle, que foi utilizado como base para o desenvolvimento deste trabalho. São aplicados parâmetros e métricas de Qualidade do Contexto sobre as informações coletadas no ambiente, de forma que possam ser criadas maiores garantias para que o contexto formulado no ambiente esteja adequado às preferências e necessidades do usuário. As adaptações no ambiente são realizadas utilizando a Hipermídia Adaptativa, sendo que os tipos de informações coletadas são o perfil cognitivo do usuário e sua velocidade de conexão, que são capturados por meio dos módulos SEDECA 2.0 e U-SEA 2.0, respectivamente e que também sofreram uma reestruturação em seu modo de operação. Além disso, um módulo provê a adaptação automática da interface para o uso do ambiente em dispositivos móveis. Como resultados, os testes de Software e com usuários demonstraram que o ambiente UVLEQoC operou de forma satisfatória, tendo como base as avaliações feitas pelo grupo de pessoas que testou os módulos e seu funcionamento. Os questionários aplicados do SUS e sobre os módulos desenvolvidos, que contou com a sua validação por meio da técnica de Alfa de Cronbach, apresentaram resultados dentro de uma escala considerada como boa, o que reproduz a completude dos objetivos propostos neste trabalho, mesmo que algumas limitações e dificuldades tenham sido identificados durante o desenvolvimento.

L’Internet des Objets (IdO) est un nouveau paradigme, dont l’idée de base est d’avoir un grand nombre d’objets de façon ubiquitaire. Ces objets sont capables d’interagir les uns avec les autres et de coopérer avec leurs voisins en partageant des données acquises directement en mesurant certains faits. Tout cela, afin d’atteindre des objectifs communs. Cette information ne représente pas seulement l’état des utilisateurs, mais aussi les processus dans lesquels ils sont impliqués, on appelle cela le Contexte. Le Contexte informe à la fois la reconnaissance et le mappage des opérations en fournissant une vue structurée et unifiée du monde dans lequel un système fonctionne.Avec l’IdO, de nombreuses applications récupèrent des informations de contexte concernant les utilisateurs (propriétaires de contexte) tels que, leurs habitudes, leurs comportements et leur «sentiment» (état de santé). Ceci, offre alors beaucoup d’avantages pour les utilisateurs, mais au dépend de leur intimité. La problématique de recherche de cette thèse se situe dans la vision orientée sémantique de l’IdO. Dans ce cadre, les technologies sémantiques jouent un rôle clé dans l’exploitation des solutions de modélisation parfaitement appropriée pour intégrer la notion de sécurité de la vie privée dans l’IdO. Les applications et services (consommateurs de contexte), qui sont sensibles au contexte, attendent des données de contexte correctes et fiables afin d’adapter leurs fonctionnalités. Dans cette thèse, la qualité de Contexte (QoC) est une métadonnée qui est associée aux informations de contexte. Elle décrit une série de critères exprimant la qualité de l’information de contexte. Ces métadonnées peuvent être utilisées pour déterminer la valeur de l’information pour une application particulière dans une situation particulière. Nous explorons des solutions intergicielles et des structures logiciels pour intégrer la gestion de la vie privée et QoC dans l’IdO.Cette thèse se distingue des autres recherches du domaine de la gestion de contexte et tient compte du découplage des participants IdO; à savoir, les propriétaires des informations de contexte et les consommateurs de ces informations de contexte. De plus, nous considérons la QoC comme un facteur affectant la vie privée des individus. Cette thèse fournit les contributions suivantes selon deux axes: Axe 1: Concevoir un contexte contrat méta-modèle pour définir la vie privée et QoC pour exprimer les préoccupations des propriétaires et consommateurs de contexte; basé sur la confiance réciproque, puisque les deux sont découplés. Cette conception est basée sur deux points : Premièrement, nous considérons que la vie privée est la capacité des propriétaires de contexte à contrôler quoi, comment, quand, où et avec qui partager des informations. Par conséquent, nous identifions quatre dimensions de la vie privée (le but, la visibilité, la rétention, la QoC), pour les utiliser au moment de la définition des politiques et des obligations d’accès. Deuxièmement, les consommateurs de contexte attendent un certain niveau de QoC afin d’accomplir leurs tâches. Nous proposons alors de définir deux types de contrat de contexte : le premier, pour la partie producteur et un second pour le côté du consommateur.Axe 2 : Proposer un algorithme pour créer des accords entre les producteurs et les consommateurs de contexte en évaluant et en comparant les exigences par rapport aux garanties indiquées sur leurs contrats de contexte respectives.Comme les deux participants de l’IdO ont des contrats symétriques, quand un participant définit ses besoins, l’autre définit ses garanties. Le processus de correspondance de ces contrats de contexte vérifie si les exigences de l’une des parties sont incluses dans les garanties offertes par l’autre partie.A partir de cette définition, nous avons conçu des algorithmes pour déterminer si l’accès et la consommation sont autorisés ou non, selon la correspondance des contrats de contexte / The Internet of Things (IoT) is a novel paradigm, which basic idea is the pervasive presence around us of a variety of things or objects that are able to interact with each other and cooperate with their neighbors by sharing data, directly acquired by measuring some facts, in order to reach common goals. This information not only represents the state of users but also the processes in which they are involved, this is called the Context. The context informs both recognition and mapping operations by providing a structured, unified view of the world in which a system operates. With the IoT, many applications consume context information concerning users (context owners) such as, daily routines, behaviors and health, offering lots of benefits to users, but compromising their privacy. The re-search problematic of this thesis lies within the “semantic-oriented” IoT vision. In this context, semantic technologies play a key role in exploiting appropriate modelling solutions for integrating privacy security into the IoT. Context-aware applications and services (context consumers) expect correct and reliable context data to adapt their functionalities. In this thesis the Quality of Context (QoC) is meta-data attached to context information describing a range of criteria that express context information quality. These meta-data can be used to determine the worth of the information for a particular application in a particular situation. We explore middleware and framework solutions to integrate the management of privacy and QoC in the IoT. This thesis is distinguished from other context management domain researches by bearing in mind the decoupling of the IoT participants, i.e., the owners of context information and the consumers of this context information. Moreover, we consider the QoC as a factor affecting the privacy of individuals. This thesis provides the following contributions along two axis: 1. Designing a Context Contract Meta-model to define privacy and QoC concerns of decoupled context owners and context consumers based on reciprocal trust. This design is based on two points. Firstly, we consider that privacy is the capacity of context owners to control what, how, when, where and with whom to share information. Therefore, we identify four privacy dimensions (purpose, visibility, retention, QoC), and use them in the definition of access policies and obligations. Secondly, context consumers expect a certain QoC level in order to perform their tasks. We then propose to define two kinds of context contract for the producer and the consumer sides as follows: Context producer contract: A context contract whose clauses are expressions of the production of context data, of privacy requirements, and of QoC guarantees; Context consumer contract: A context contract whose clauses are expressions of the consumption of context data, of QoC requirements, and of privacy guarantees. Each context contract is created without the knowledge of is counter party.2. Proposing an algorithm to create agreements among context producers and context consumers by evaluating and compare requirements against guarantees, stated on their respective context contracts. As both IoT participants have symmetric contracts, when one participant defines its requirements, the other one defines its guarantees. The matching process of these context contracts verifies if the requirements of one party are included within the guarantees offered by the other party. Therefore, taking a decision based on this compatibility match from the producer point of view is to permit or deny the access to context data. Complementarily, from a consumer point of view, the consumption of context data is permitted or denied. From this definition, we designed algorithms to determine whether access and consumption are authorized or not, according to the context contracts matching

Made available in DSpace on 2016-08-17T14:53:29Z (GMT). No. of bitstreams: 1 DISSERTACAO Dejailson Nascimento Pinheiro.pdf: 1433962 bytes, checksum: 4173dad207f09fa2033a834f86a5d4b7 (MD5) Previous issue date: 2014-08-06 / Mobile Social Networks (MSNs) are social structures in which members relate in groups and interaction is accomplished through information and communication technologies using portable devices and wireless network technologies. Healthcare is one among the many possible areas of RSMs application. The MobileHealthNet project, developed in partnership by UFMA and PUC-Rio, aims to develop a middleware that allows access to social networks and facilitate the development of collaborative services targeting the health domain, the exchange of experiences and communication between patients and health professionals, as well as a better management of health resources by government agencies. An important aspect in the development of the MobileHealthNet middleware is the infrastructure necessary for the gathering, distribution and processing of context data. In this master thesis we propose a software infrastructure incorporated to the MobileHealthNet middleware that allows the specification, acquisition, validation and distribution of context data, considering quality requirements, making them available to context-aware applications. The distribution of context data is based on a data-centric the publish/subscribe model, using the OMG-DDS specification. / Redes Sociais Móveis (RSMs) são estruturas sociais em que seus membros relacionam-se em grupos e a interação é realizada através de tecnologias de informação e comunicação utilizando dispositivos portáteis com acesso a tecnologias de rede sem fio. Entre os muitos domínios de aplicação das RSMs, temos a área da saúde. O projeto MobileHealthNet, desenvolvido em parceria pela UFMA e PUC-Rio, tem por objetivo desenvolver um middleware que permita o acesso às redes sociais e facilite o desenvolvimento de serviços colaborativos para o setor da saúde, a troca de experiências e a comunicação entre pacientes e profissionais da saúde, além de uma melhor gestão dos recursos da saúde por órgãos governamentais. Um aspecto importante no desenvolvimento do middleware proposto pelo projeto MobileHealthNet é a infraestrutura necessária para a coleta, distribuição e processamento de dados de contexto. Neste trabalho de mestrado é proposta uma infraestrutura de software incorporada ao middleware MobileHealthNet que permite a especificação, obtenção, validação e distribuição de dados de contexto, considerando requisitos de qualidade, tornando-os disponíveis a aplicações sensíveis ao contexto. A distribuição dos dados de contexto é baseado no modelo publish/subscribe centrado em dados, utilizando-se a especificação OMG-DDS.