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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Weighted Granular Best Matching Algorithm For Context-aware Computing Systems

Kocaballi, Ahmet Baki 01 January 2005 (has links) (PDF)
Weighted granular best matching algorithm is proposed for the operation of context matching in context-aware computing systems. New algorithm deals with the subjective, fuzzy and multidimensional characteristics of contextual information by using weights and a granular structure for contextual information. The proposal is applied on a case: CAPRA &ndash / Context-Aware Personal Reminder Agent tool to show the applicability of the new context matching algorithm. The obtained outputs showed that proposed algorithm produces the results which are more sensitive to the user&rsquo / s intention, more adaptive to the characteristics of the contextual information and applicable to a current Context-aware system.
192

Intelligent actor mobility in wireless sensor and actor networks

Krishnakumar, Sita Srinivasaraghavan 19 May 2008 (has links)
Wireless sensor and actor networks are used in situations where interaction is required between a network and the environment in which the network is deployed. This research studies the functioning of a single mobile actor deployed in a sparsely connected network. When deployed in a sparsely connected network, an actor has to do more than acting. It has to perform the additional duties of an event collector - collecting events from the naturally occurring clusters - so that it can fulfill its primary obligation as an actor. The path taken by a mobile actor node is generated by a mobility model. The existing random mobility models are non-intelligent mobility models. While they may bring about a chance meeting between an actor and an event, there is no guarantee that these meetings will actually happen. This motivates the development of intelligent mobility models for the actor node, which will generate paths that are reflective of the network in which the actor is deployed. In this thesis, intelligent mobility models for the actor node were developed using the inherent clustering information of a sparsely connected network. These models were applied to an actor node in networks of varying sparseness and the following conclusions were reached: (i) Existing random mobility models are unsuitable for an actor in a sparsely connected network. (ii) High probability of events can be sensed when a sparsely connected network is used. (iii) 100% event detection by the actor node is possible at higher speeds. (iv) When the single actor functioned both as an event collector and as an actor, the number of events acted upon by the actor was very close to the number of events acted upon by an actor in a fully connected network. (v) The Correlation Theory developed in this research suggests using a combination of the intelligent mobility models to obtain the best performance results under all circumstances. (vi) Early detection of events can be supported where it is required. All of the above conclusions justify the deployment of a single actor and a sparsely connected network, either individually or as a combination.
193

Infrastructure mediated sensing

Patel, Shwetak Naran 08 July 2008 (has links)
Ubiquitous computing application developers have limited options for a practical activity and location sensing technology that is easy-to-deploy and cost-effective. In this dissertation, I have developed a class of activity monitoring systems called infrastructure mediated sensing (IMS), which provides a whole-house solution for sensing activity and the location of people and objects. Infrastructure mediated sensing leverages existing home infrastructure (e.g, electrical systems, air conditioning systems, etc.) to mediate the transduction of events. In these systems, infrastructure activity is used as a proxy for a human activity involving the infrastructure. A primary goal of this type of system is to reduce economic, aesthetic, installation, and maintenance barriers to adoption by reducing the cost and complexity of deploying and maintaining the activity sensing hardware. I discuss the design, development, and applications of various IMS-based activity and location sensing technologies that leverage the following existing infrastructures: wireless Bluetooth signals, power lines, and central heating, ventilation, and air conditioning (HVAC) systems. In addition, I show how these technologies facilitate automatic and unobtrusive sensing and data collection for researchers or application developers interested in conducting large-scale in-situ location-based studies in the home.
194

Uma infraestrutura para monitoramento de sistemas cientes do contexto. / An infrastructure for monitoring systems aware of the context.

André Luiz Barbosa Rodrigues 07 August 2009 (has links)
Aplicações ubíquas e pervasivas são cientes do contexto dos recursos utilizados no que diz respeito à disponibilidade e qualidade. Esta classe de aplicações pode se beneficiar de mecanismos para descobrir recursos que atendam aos requisitos não-funcionais desejados, e mecanismos para monitorar a qualidade destes recursos. Neste trabalho é proposta uma arquitetura para dois serviços que deveriam ser incluídos na infra-estrutura de suporte a ser utilizada pelas aplicações mencionadas: um Serviço de Contexto, que provê acesso a informações de contexto, e um Serviço de Descoberta, que permite a descoberta dinâmica de recursos, levando em conta restrições de contexto a serem satisfeitas. Estes serviços se apóiam em Agentes de Recursos, que efetivamente monitoram os recursos e sensores. Uma implementação de referência foi desenvolvida, oferecendo os serviços mencionados na forma de Serviços Web e implementando os Agentes de Recursos empregando um padrão de projeto simples. Para avaliar os serviços estes foram utilizados como infra-estrutura para o desenvolvimento de um sistema tolerante a falhas e uma aplicação de assistência domiciliar remota (tele-saúde). O desempenho dos serviços também foi avaliado. / Ubiquitous and pervasive applications are aware of the context of the used resources, regarding their availability and quality. This class of application can benefit from mechanisms to discover resources that meet their non-functional requirements and mechanisms to monitor the quality of those resources. We proposed architecture for two services that should be included in the supporting infrastructure used by the mentioned applications: a Context Service that provides access to context information; and a Discovery Service, which allows the dynamic discovery of resources, considering context constraints to be satisfied. These services rely on Resource Agents, which monitor the actual resources and sensors. A reference implementation was developed, providing the mentioned services as Web Services and implementing the Resource Agents using a simple design pattern. To evaluate these services were employed them as the infrastructure to design a fault tolerant system and a remote assisted living application. The performance of the services was also evaluated.
195

Modèle profond pour le contrôle vocal adaptatif d'un habitat intelligent / Deep model for adaptive vocal control of a smart home

Brenon, Alexis 14 December 2017 (has links)
Les habitats intelligents, résultants de la convergence de la domotique, de l'informatique ubiquitaire et de l'intelligence artificielle, assistent leurs habitants dans les situations du quotidien pour améliorer leur qualité de vie.En permettant aux personnes dépendantes et âgées de rester à domicile plus longtemps, ces habitats permettent de fournir une première réponse à des problèmes de société comme la dépendance due au vieillissement de la population.En nous plaçant dans un habitat contrôlé par la voix, l'habitat doit répondre aux requêtes d’un utilisateur concernant un ensemble d’actions pouvant être automatisées (contrôle des lumières, des volets, des dispositifs multimédia, etc.).Pour atteindre cet objectif, le système de contrôle de l'habitat a besoin de prendre en compte le contexte dans lequel un ordre est donné mais également de connaitre les habitudes et préférences de l’utilisateur.Pour cela, le système doit pouvoir agréger les informations issues du réseau de capteurs domotiques hétérogènes et prendre en compte le comportement (variable) de l'utilisateur.La mise au point de systèmes de contrôle intelligent d'un habitat est particulièrement ardue du fait de la grande variabilité concernant aussi bien la topologie des habitats que les habitudes des utilisateurs.Par ailleurs, l'ensemble des informations contextuelles doivent être représentées dans un référentiel commun dans un objectif de raisonnement et de prise de décision.Pour répondre à ces problématiques, nous proposons de développer un système qui d'une part modifie continuellement son modèle de manière à s'adapter à l'utilisateur, et qui d'autre part utilise directement les données issues des capteurs à travers une représentation graphique. L'intérêt et l'originalité de cette méthode sont de ne pas nécessiter d'inférence pour déterminer le contexte.Notre système repose ainsi sur une méthode d'apprentissage par renforcement profond qui couple un réseau de neurones profond du type convolutif permettant l'extraction de données contextuelles, avec un mécanisme d'apprentissage par renforcement pour la prise de décision.Ce mémoire présente alors deux systèmes, un premier reposant uniquement sur l'apprentissage par renforcement et montrant les limites de cette approche sur des environnements réels pouvant comporter plusieurs milliers d'états possibles.L'introduction de l'apprentissage profond a permis la mise au point du second système, ARCADES, dont les bonnes performances montrent la pertinence d'une telle approche, tout en ouvrant de nombreuses voies d'améliorations. / Smart-homes, resulting of the merger of home-automation, ubiquitous computing and artificial intelligence, support inhabitants in their activity of daily living to improve their quality of life.Allowing dependent and aged people to live at home longer, these homes provide a first answer to society problems as the dependency tied to the aging population.In voice controlled home, the home has to answer to user's requests covering a range of automated actions (lights, blinds, multimedia control, etc.).To achieve this, the control system of the home need to be aware of the context in which a request has been done, but also to know user habits and preferences.Thus, the system must be able to aggregate information from a heterogeneous home-automation sensors network and take the (variable) user behavior into account.The development of smart home control systems is hard due to the huge variability regarding the home topology and the user habits.Furthermore, the whole set of contextual information need to be represented in a common space in order to be able to reason about them and make decisions.To address these problems, we propose to develop a system which updates continuously its model to adapt itself to the user and which uses raw data from the sensors through a graphical representation.This new method is particularly interesting because it does not require any prior inference step to extract the context.Thus, our system uses deep reinforcement learning; a convolutional neural network allowing to extract contextual information and reinforcement learning used for decision-making.Then, this memoir presents two systems, a first one only based on reinforcement learning showing limits of this approach against real environment with thousands of possible states.Introduction of deep learning allowed to develop the second one, ARCADES, which gives good performances proving that this approach is relevant and opening many ways to improve it.
196

AdaptiveRME e aspectCompose: um middleware adaptativo e um processo de composição orientado a aspecto para o desenvolvimento de software móvel e ubíquo / AdaptiveRME and aspectCompose: A middleware adaptative and a guided process of composition the aspects for the development of software móvel and ubiquitous

Rocha, Lincoln Souza January 2007 (has links)
ROCHA, Lincoln Souza. AdaptiveRME e aspectCompose: um middleware adaptativo e um processo de composição orientado a aspecto para o desenvolvimento de software móvel e ubíquo. 2007. 102 f. Dissertação (Mestrado em ciência da computação)- Universidade Federal do Ceará, Fortaleza-CE, 2007. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-07-11T18:16:05Z No. of bitstreams: 1 2007_dis_lsrocha.pdf: 2405680 bytes, checksum: 7063a81265f0d1a3757c5dff48a28581 (MD5) / Approved for entry into archive by Rocilda Sales (rocilda@ufc.br) on 2016-07-18T16:10:13Z (GMT) No. of bitstreams: 1 2007_dis_lsrocha.pdf: 2405680 bytes, checksum: 7063a81265f0d1a3757c5dff48a28581 (MD5) / Made available in DSpace on 2016-07-18T16:10:13Z (GMT). No. of bitstreams: 1 2007_dis_lsrocha.pdf: 2405680 bytes, checksum: 7063a81265f0d1a3757c5dff48a28581 (MD5) Previous issue date: 2007 / Ubiquitous computing is an extensive computational paradigm, which can provide solutions to regular citizens or can be useful to handle complex medical environment data, for example. This paradigm proposes a new human-computer interaction approach based on the proactivity of computers that makes users’ life easier. However, this approach demands a high level of collaboration and communication among the computational elements that compose the mobile and ubiquitous environments. One of the main challenges is related to the way of conceiving software systems capable of dealing with the high variation of resources and services, along with guaranteeing the interoperability among the diversity of computational elements that compose these environments. Therefore, this work proposes an adaptive middleware for móbile and ubiquitous environments that intends to solve heterogeneity and dynamicity problems. This dissertation also proposes a software composition process to reduce coupling between the proposed middleware and applications. The middleware uses dynamic adaptation and support for context-aware software development mechanisms, and the composition process uses Aspect-Oriented Programming (AOP) techniques. A case study is developed to evaluate the adaptive middleware’s functionalities and demonstrate the composing process. Furthermore, a performance analysis is presented to measure the proposed middleware’s impact in a wireless network. / A computação ubíqua é um paradigma computacional de grande abrangência, com aplicabilidades tanto para o cotidiano de um cidadão comum quanto para o tratamento de informações complexas em ambientes hospitalares. Este paradigma propõe uma nova forma de interação homem-computador baseada na proatividade dos computadores para facilitar a vida dos usuários. Entretanto, tal forma de interação demanda um alto grau de colaboração e comunicação entre os elementos computacionais que compõem os ambientes móveis e ubíquos. Um dos principais desafios está relacionado a maneira de como conceber sistemas de software capazes de lidar com a alta variação de recursos e serviços, além de garantir a interoperabilidade entre os diversos elementos computacionais que compõem estes ambientes. Este trabalho propõe, então, um middleware adaptativo para ambientes móveis e ubíquos com o objetivo de solucionar problemas de heterogeneidade e dinamicidade. Para diminuir o acoplamento entre o middleware proposto e as aplicações que o utilizam, esta dissertação também propõe um processo de composição de software. O middleware utiliza mecanismos de adaptação dinâmica e suporte ao desenvolvimento de software sensível ao contexto, e o processo de composição faz uso de técnicas de Programação Orientada a Aspectos (POA). Um estudo de caso é desenvolvido para avaliar a funcionalidade do middleware adaptativo e demonstrar a utilização do processo de composição. Além disso, uma análise de desempenho é apresentada para medir o impacto provocado pelo uso do middleware proposto em um ambiente de rede sem fio.
197

A hybrid model for context-aware proactive recommendation / Un modèle hybride pour la recommandation proactive et contextuelle

Akermi, Imen 05 July 2017 (has links)
L'accès aux informations pertinentes, adaptées aux besoins et au profil de l'utilisateur est un enjeu majeur dans le cadre actuel caractérisé par une prolifération massive des ressources d'information hétérogènes. Le développement d'appareils mobiles équipés de plusieurs fonctionnalités telles que la caméra, le WIFI, la géo-localisation et bien plus d'autres permettent aux systèmes mobiles de recommandation actuels d'être hautement contextualisés et pouvant fournir à l'utilisateur des informations pertinentes au bon moment quand il en a le plus besoin, sans attendre qu'il établisse une interaction avec son appareil. C'est dans ce cadre que s'insère notre travail de thèse. En effet, nous proposons une approche de recommandation contextuelle et proactive dans un environnement mobile qui permet de recommander des informations pertinentes à l'utilisateur sans attendre à ce que ce dernier initie une interaction. Un système proactif peut prendre la forme d'un guide touristique personnalisé qui se base sur la localisation et les préférences de l'utilisateur pour suggérer à ce dernier des endroits intéressants sans qu'il fournisse, sa préférence ou une requête explicite. Cela permettra de réduire les efforts, le temps et l'interaction de l'utilisateur avec son appareil mobile et de présenter les informations pertinentes au bon moment et au bon endroit. Cette approche prend aussi en considération les situations où la recommandation pourrait déranger l'utilisateur. Il s'agit d'équilibrer le processus de recommandation contre les interruptions intrusives. En effet, il existe différents facteurs et situations qui rendent l'utilisateur moins ouvert aux recommandations. Comme nous travaillons dans le contexte des appareils mobiles, nous considérons que les applications mobiles telles que la caméra, le clavier, l'agenda, etc., sont de bons représentants de l'interaction de l'utilisateur avec son appareil puisqu'ils représentent en quelque sorte la plupart des activités qu'un utilisateur pourrait entreprendre avec son appareil mobile au quotidien, comme envoyer des messages, converser, tweeter, naviguer ou prendre des photos. / Just-In-Time recommender systems involve all systems able to provide recommendations tailored to the preferences and needs of users in order to help them access useful and interesting resources within a large data space. The user does not need to formulate a query, this latter is implicit and corresponds to the resources that match the user's interests at the right time. Our work falls within this framework and focuses on developing a proactive context-aware recommendation approach for mobile devices that covers many domains. It aims at recommending relevant items that match users' personal interests at the right time without waiting for the users to initiate any interaction. Indeed, the development of mobile devices equipped with persistent data connections, geolocation, cameras and wireless capabilities allows current context-aware recommender systems (CARS) to be highly contextualized and proactive. We also take into consideration to which degree the recommendation might disturb the user. It is about balancing the process of recommendation against intrusive interruptions. As a matter of fact, there are different factors and situations that make the user less open to recommendations. As we are working within the context of mobile devices, we consider that mobile applications functionalities such as the camera, the keyboard, the agenda, etc., are good representatives of the user's interaction with his device since they somehow stand for most of the activities that a user could use in a mobile device in a daily basis such as texting messages, chatting, tweeting, browsing or taking selfies and pictures.
198

Uma infraestrutura para monitoramento de sistemas cientes do contexto. / An infrastructure for monitoring systems aware of the context.

André Luiz Barbosa Rodrigues 07 August 2009 (has links)
Aplicações ubíquas e pervasivas são cientes do contexto dos recursos utilizados no que diz respeito à disponibilidade e qualidade. Esta classe de aplicações pode se beneficiar de mecanismos para descobrir recursos que atendam aos requisitos não-funcionais desejados, e mecanismos para monitorar a qualidade destes recursos. Neste trabalho é proposta uma arquitetura para dois serviços que deveriam ser incluídos na infra-estrutura de suporte a ser utilizada pelas aplicações mencionadas: um Serviço de Contexto, que provê acesso a informações de contexto, e um Serviço de Descoberta, que permite a descoberta dinâmica de recursos, levando em conta restrições de contexto a serem satisfeitas. Estes serviços se apóiam em Agentes de Recursos, que efetivamente monitoram os recursos e sensores. Uma implementação de referência foi desenvolvida, oferecendo os serviços mencionados na forma de Serviços Web e implementando os Agentes de Recursos empregando um padrão de projeto simples. Para avaliar os serviços estes foram utilizados como infra-estrutura para o desenvolvimento de um sistema tolerante a falhas e uma aplicação de assistência domiciliar remota (tele-saúde). O desempenho dos serviços também foi avaliado. / Ubiquitous and pervasive applications are aware of the context of the used resources, regarding their availability and quality. This class of application can benefit from mechanisms to discover resources that meet their non-functional requirements and mechanisms to monitor the quality of those resources. We proposed architecture for two services that should be included in the supporting infrastructure used by the mentioned applications: a Context Service that provides access to context information; and a Discovery Service, which allows the dynamic discovery of resources, considering context constraints to be satisfied. These services rely on Resource Agents, which monitor the actual resources and sensors. A reference implementation was developed, providing the mentioned services as Web Services and implementing the Resource Agents using a simple design pattern. To evaluate these services were employed them as the infrastructure to design a fault tolerant system and a remote assisted living application. The performance of the services was also evaluated.
199

Caracterização de desafios e estratégias de teste para sistemas adaptativos

Siqueira, Bento Rafael 30 June 2016 (has links)
Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-05-09T12:58:24Z No. of bitstreams: 1 DissBRS.pdf: 3255630 bytes, checksum: e4d94f1ee923813cfd91e76e992dbfa8 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-06-01T18:49:57Z (GMT) No. of bitstreams: 1 DissBRS.pdf: 3255630 bytes, checksum: e4d94f1ee923813cfd91e76e992dbfa8 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-06-01T18:50:12Z (GMT) No. of bitstreams: 1 DissBRS.pdf: 3255630 bytes, checksum: e4d94f1ee923813cfd91e76e992dbfa8 (MD5) / Made available in DSpace on 2017-06-01T19:49:40Z (GMT). No. of bitstreams: 1 DissBRS.pdf: 3255630 bytes, checksum: e4d94f1ee923813cfd91e76e992dbfa8 (MD5) Previous issue date: 2016-06-30 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Context: Traditional testing approaches, considering the context of Adaptive Systems (ASs), have been evaluated incipiently and superficially with respect to their effectiveness in identifying faults. It is very clear the challenge of guaranteeing the correctness of ASs, due to the adaptive properties of these systems. Thus, the following question raises: how to characterise adequately and broadly the difficulties for testing ASs? There is not an approach that is driven by challenges found in the literature. Goals: In this work, we analysed and characterised the challenges faced by the testing activity when applied to ASSs. By characterising the challenges, we investigated testing strategies based on them. Methodology: In order to achieve the goals, we performed the following steps: (i) characterising the state-of-art of testing of ASs, using a Systematic Literature Review (SLR); (ii) investigating the challenges in source codes of real ASs that are available online in source code repositories; (iii) defining the testing strategy named T, based on the characterised challenges; (iv) defining the testing strategy T* based on the challenges and comprised by three testing approaches; (v) evaluating the effectiveness of the strategies T and T*; and (vi) investigating the challenges along the application of T and T*. Results: the main results were: (i) a characterisation of fine-grained and coarse-grained challenges for testing ASs; and (ii) two testing strategies based on such challenges. We evaluated the strategies by running an exploratory study which encompassed one AS and both testing strategies. Conclusion: The characterisation of challenges supported the definition and execution of the testing strategies. These strategies were able to reduce the impact of the challenges and to identify faults in the AS. / Contexto: Abordagens de teste tradicionais sao ainda incipientes e superficialmente avaliadas quanto a sua efetividade em revelar defeitos em Sistemas Adaptativos (SAs). E nítido o desafio de garantir a corretude de SAs levando-se em consideração as características de adaptacao desses sistemas, culminando na seguinte pergunta: como caracterizar adequadamente, de forma abrangente, as dificuldades para se testar SAs? Na literatura nao foi encontrada qualquer estrategia de teste que seja guiada por desafios de teste caracterizados. Objetivos: Neste trabalho buscou-se compreender e caracterizar os desafios impostos a atividade de teste de SAs. Uma vez caracterizados, os desafios, propos-se investigar estrategias de teste baseadas nestes desafios. Metodologia: Para atingir o objetivo seguiram-se as etapas: (i) caracterizacao do estado da arte por meio de uma Revisao Sistematica (RS); (ii) investigacao da existencia de desafios de teste em SAs presentes em repositórios de código-fonte; (iii) definho de uma estrategia de teste, denominada T, com base nos desafios caracterizados da RS; (iv) definicao de uma estrategia de teste combinada, denominada T*, composta por três abordagens de teste; (v) avaliaçao da efetividade das estrategias T e T*; e, por fim, (vi) investigacao da presença dos desafios nos SAs analisados, por meio das estrategias T e T*. Resultados: Os principais resultados foram: (i) uma caraterizacao de desafios para o teste de SAs; e (ii) e uma definicao de estrategias de teste baseadas nos desafios caracterizados. A avaliacao foi realizada com a aplicacao de um estudo exploratório, utilizando um SA, de uma estrategia de teste somente baseada em desafios (T) e de uma estrategia de teste baseada em desafios combinada com outras abordagens (T*), a fim de comparar os resultados de ambas as estrategias. Conclusão: A caracterizacao dos desafios auxiliou na definicao e execucao de estrategias de teste, as quais mitigaram os desafios presentes nos SAs e puderam identificar defeitos.
200

SYSSU-DTS: um sistema de suporte à computaÃÃo ubÃqua baseado em espaÃo de tuplas distribuÃdo / SYSSU-DTS: a support system for ubiquitous computing based on distributed tuple spaces

Benedito Josà de Almeida Neto 29 August 2013 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / nÃo hà / A evoluÃÃo das tecnologias mÃveis favorece o surgimento de sistemas capazes de antever as necessidades do usuÃrio e se adaptar Ãs variaÃÃes de seu contexto de forma imperceptÃvel. Tais sistemas, denominados sistemas ubÃquos, enfrentam o desafio da adaptaÃÃo dinÃmica em um cenÃrio altamente distribuÃdo, heterogÃneo e volÃtil, uma vez que pode se tornar difÃcil coletar e processar informaÃÃes contextuais oriundas de fontes desconhecidas e distribuÃdas. O problema em questÃo à o gerenciamento de dados contextuais em cenÃrios sujeitos a mobilidade e conexÃes intermitentes entre dispositivos mÃveis e servidores. A fim de facilitar o desenvolvimento de sistemas ubÃquos, este trabalho estende um sistema de suporte existente, chamado SysSU (LIMA et al., 2011), que foi baseado em espaÃos de tuplas centralizado. Com o objetivo de gerenciar informaÃÃes de contexto distribuÃdas, à adotada uma abordagem de espaÃo de tuplas descentralizada, oferecendo aos componentes dos sistemas ubÃquos a capacidade de interaÃÃo e cooperaÃÃo em situaÃÃes de total descentralizaÃÃo. Sendo assim, esta dissertaÃÃo propÃe o SysSU-DTS (System Support for Ubiquity - Distribute Tuple Space), um sistema de suporte que fornece a funcionalidade de coordenaÃÃo de sistemas ubÃquos em ambientes abertos, onde nenhuma suposiÃÃo sobre os recursos disponÃveis deve ser feita. O SysSU-DTS à focado em sistemas ubÃquos baseado em dispositivos mÃveis, como smartphones, tablets e ultrabooks, que podem se comunicar atravÃs de redes mÃveis Ad hoc (MANET - Mobile Ad hoc Network). O SysSU-DTS representa informaÃÃes contextuais por meio de tuplas e permite o acesso transparente a informaÃÃes de contexto disponÃveis, estejam elas localizadas dentro do dispositivo mÃvel, em um servidor ou em outro dispositivo mÃvel prÃximo. A partir do acesso a informaÃÃes de contexto oriundas de diferentes provedores, as aplicaÃÃes ubÃquas e sensÃveis ao contexto que adotem o suporte do SysSU-DTS podem ter uma visÃo do contexto global das entidades envolvidas no sistema. AlÃm disso, o SysSU-DTS implementa um mecanismo de escopo que permite a formaÃÃo de subconjuntos de informaÃÃes contextuais disponÃveis, evitando gerenciamento de informaÃÃes desnecessÃrias. SÃo apresentados resultados experimentais obtidos em uma avaliaÃÃo de desempenho realizada em um testbed composto por smartphones e tablets. Esta avaliaÃÃo demonstra a viabilidade prÃtica da abordagem proposta e como o SysSU-DTS promove a distribuiÃÃo de informaÃÃes de contexto adaptando-se dinamicamente a provedores de contexto locais, infra-estruturados e distribuÃdos em redes Ad hoc. / The evolution of mobile technologies allows the emerging of ubiquitous systems, able to anticipate userâs needs and to seamlessly adapt to context changes. These systems present the problem of dynamic adaptation in a highly distributed, heterogeneous and volatile environment, since it may be difficult to collect and process context information from distributed unknown sources. The problem faced is the management of contextual data in scenarios with mobility and intermittent connections between mobile devices and servers. In order to facilitate the development of such systems, this work extends an existing support system based on centralized tuple spaces, called SysSU (LIMA et al., 2011), aiming at the management of distributed information. Hence, a decentralized tuple space approach is adopted, offering to ubiquitous systems components the capability of interaction and cooperation in scenarios of total decentralization. Thus, this work introduces SysSU-DTS (System Support for Ubiquity - Distribute Tuple Space), a system support that provides functionality for coordinating ubiquitous systems in open environments, where no assumptions about available resources should be made. It focuses on ubiquitous systems based on mobile devices such as smartphones, tablets and ultrabooks, which can communicate through a Mobile Ad hoc Network (MANET). SysSU-DTS represents context information by tuples and allows a transparent access to spread context, as follows: (i)local access, which accesses an internal device tuple space; (ii) infrastructured access, tuple spaces located on a server accessed using an infrastructured network; or (iii) Ad hoc access, interacting directly with tuple spaces located in nearby devices via the formation of an Ad hoc network. From the access to different context providers, ubiquitous and context-aware applications, using SysSU-DTSs support, can have an insight of global context related to the system entities. In addition, SysSU-DTS implements a scope mechanism that allows the formation of available contextual information subsets. This mechanism restricts access to contextual tuples only to members of the same scope, avoiding unnecessary information management. This dissertation reports some experimental results obtained in a performance evaluation using a testbed of smartphones and tablets. The evaluation shows the practical feasibility of our approach and point out how SysSU-DTS can grant context data distribution with dynamically adapting to local, infrastructured and distributed over Ad hoc networks context providers.

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