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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.
21

Semantic-Based Context-Aware Service Discovery in Pervasive-Computing Environments

El-Sayed, Abdur-Rahman January 2006 (has links)
Recent technological advancements are enabling the vision of pervasive or ubiquitous computing to become a reality. Service discovery is vital in such a computing paradigm, where a great number of devices and software components collaborate unobtrusively and provide numerous services. Current service-discovery protocols do not make use of contextual information in discovering services, and as a result, fail to provide the most appropriate and relevant services for users. In addition, current protocols rely on keyword-based search techniques and do not consider the semantic description of services. Thus, they suffer from poor precision and recall. To address the need for a discovery architecture that supports the envisioned scenarios of pervasive computing, we propose a context-aware service-discovery protocol that exploits meaningful contextual information, either static or dynamic, to provide users with the most suitable and relevant services. The architecture relies on a shared, ontology-based, semantic representation of services and context to enhance precision and recall, and to enable knowledge sharing, capability-based search, autonomous reasoning, and semantic matchmaking. Furthermore, the architecture facilitates a dynamic service-selection mechanism to filter and rank matching services, based on their dynamic contextual attributes, which further enhances the discovery process and saves users time and effort. Our empirical results indicate the effectiveness and feasibility of the proposed architecture.
22

Non-Intrusive Computing

Chen, Hao January 2008 (has links)
Pervasive computing is an important trend today. It concerns devices and services in a smart space that interact with users in a simple, natural, and harmonious way. Many problems in this domain have been studied from different perspectives in various projects. However, one important characteristic of pervasive computing, which is how to make it non-intrusive so that users can focus on their tasks, has received little formal attention. Nowadays, many computing entities including smart devices, and software components, are involved in our daily lives, and users need to deal with them as well as with other people. Besides, people are easy to reach with multiple devices. We believe there should be a systematic way to help users avoid intrusive ones. We propose a model for posing and answering two questions: will an interaction intrude on its receiver if delivered, and given that the interaction is deliverable, how can it be delivered effectively and not too overtly? With this model, the intrusion problem is analyzed and the essential factors are identified. A quantitative approach is used, so that factors have quantitative values for comparison and computation. We also apply context to refine them in order to achieve better results. We then illustrate how to materialize the model and build a system whose design is inspired by the Jabber framework that includes a collection of standards, technologies, and projects for instant messaging. The discussion is at a general level that does not depend on Jabber. However, by choosing Jabber in implementation, we reuse existing software and technologies, and benefit from Jabber/XMPP standardization, its low entry barrier for application developers, and its rich community support. The main contributions of our work are two-fold. First, we propose a model for intrusiveness in pervasive computing. Second, we address the problem at the system level by designing and realizing it. We also make use of standardized instant-messaging technologies, more precisely Jabber, in the system instantiation to reuse existing software, making the system more flexible and extensible.
23

A dynamic trust-based context-aware secure authentication framework for pervasive computing environments

Abi-Char, Pierre 30 March 2010 (has links) (PDF)
To provide personalized services to users in pervasive environments, we should consider both user's privacy, trust and security requirements. Traditional authentication and access control mechanisms are not able to adapt their security policies to a changing context while insuring privacy and trust issues. This thesis introduces a new global vision for the protection of pervasive environments, based on context-aware principle. The aim of this thesis is to get a flexible and scalable framework including user authentication, user privacy preserving and trust management in order to optimize the access control strategy to personalized services. The first contribution include the proposal of a mutual authentication protocol supported by both robust key establishment schemes based on elliptic curves (MaptoPoint/Curve algorithm, Weil Pairing) and a dynamic model based on attributes issued from contextual data. The second contribution include the design of a new architecture built on an attribute based model and organized over 3 layers: the privacy control layer which insure the protection of the user private life by controlling their personal data, the access layer which associate authentication and access control processes while providing mechanisms dedicated to trust parameters management , and finally the service layer for service access management according to the user profile and his environment. The third contribution the implementation and the deployment of a prototype within the service delivery platform in Handicom lab of Telecom & Management SudParis.
24

Jogos em ambientes pervasivos / Games in pervasive environments

Vázquez, Sonia Andrea Lugo January 2009 (has links)
Dispositivos eletrônicos com características de computadores pessoais, como um alto poder de processamento de dados e armazenamento, estão espalhando-se cada vez mais na vida das pessoas. Variando desde notebooks a PocketPCs e, mais recentemente, telefones celulares com funcionalidades extras, os chamados smart phones, estes dispositivos oferecem recursos antes disponíveis apenas em desktops em praticamente qualquer lugar. Essa tendência em difundir cada vez mais serviços computacionais de forma a integrálos na vida das pessoas deu origem à computação pervasiva. Este ramo da computação almeja integrar os serviços computacionais de forma transparente na vida das pessoas. Um uso interessante desta nova tecnologia ainda relativamente pouco explorado é o entretenimento, mais exatamente jogos pervasivos. A criação deste novo tipo de jogo exige que certos cuidados inerentes ao ambiente pervasivo sejam tomados para aumentar a qualidade dos produtos desenvolvidos e permitir que eles de fato resultem na experiência a que se propõe. Este trabalho contribui apresentando uma pesquisa realizada sobre quais são as características desejáveis em jogos pervasivos. Para embasar essas características foi realizado um estudo sobre o que autores clássicos classificam como sendo as características de jogos tradicionais, isto é, jogos que são encontrados no universo físico, sem o auxílio de computadores. Também foram analizados trabalhos que descrevem os elementos usualmente presentes em jogos de video game, que são jogos que utilizam extensivamente recursos computacionais. Utilizando essas duas análises, é possível identificar pontos em comum entre essas duas formas de jogos, e então derivar importantes características que deveriam estar presentes em jogos pervasivos. Um jogo pervasivo foi desenvolvido para verificar se a utilização dessas características aumentam as possibilidades de um jogo pervasivo ser mais fiel ao projeto de seu idealizador. O conceito desse jogo pervasivo é similar ao conceito de um jogo de video game já existente, porém levando em consideração as necessidades do ambiente pervasivo. O jogo foi projetado utilizando as ferramentas de modelagem da UML, respeitando sempre as características quando uma decisão deveria ser tomada. Um protótipo do jogo foi desenvolvido e testado com usuários, sempre procurando avaliar quando as características estavam de fato presentes. Este trabalho finaliza apresentando uma conclusão e algumas possibilidades de trabalhos futuros. / Electronic devices with characteristics of personal computers (such as high processing power and high data storage capacities) are becoming more common in everybody lives. These devices vary from laptops to PocketPCs and, recently, to cell phones with expanded functionality, the so called smart phones. All these equipments make available everywhere possibilities that have been available before only in desktops. This new paradigm of spreading computational services and integrating them into the lives of everybody created the concept of pervasive computing. This branch of computer science aims to integrate computational services transparently into the lives of everyone. An interesting use of this new technology that still has not been widely explored is for entertainment, specifically for pervasive games. The creation of this new type of game demands certain precautions relative to the pervasive environment. This is a necessity, such that the final product has higher quality and actually corresponds to the satisfying experience it proposes. This work contributes by presenting a research about desirable characteristics in pervasive games. A study about the elements of traditional games as classified by classic authors was performed. Traditional games are games that happen in the physical universe, without the use of computers. This work also includes an analysis of different works that describe the characteristics of video games. Video games are games that extensively use computational resources. This work uses both analysis to identify similarities between these two different forms of games, and then builds important characteristics that should be present in pervasive games. A pervasive game has been developed to verify if the use of these characteristics increase the possibilities of a pervasive game meet the design goals set by its designer. The idea behind this pervasive game is similar to the concept of an existing video game, but now considering the requirements of a pervasive environment. This game was designed using the UML tools, always respecting the characteristics when a decision should be made. A prototype of this game was coded and tests have been performed with different users, always trying to verify if the characteristics were indeed present in the game. In the end of this work there is a conclusion section, along with some possibilities for future work.
25

Arquitetura da informação pervasiva: contribuições conceituais

Oliveira, Henry Poncio Cruz de [UNESP] 28 April 2014 (has links) (PDF)
Made available in DSpace on 2014-11-10T11:09:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-04-28Bitstream added on 2014-11-10T11:58:46Z : No. of bitstreams: 1 000793107.pdf: 12514867 bytes, checksum: 855b24cf3e1ca655547b5d680a190b4a (MD5) Bitstreams deleted on 2015-09-21T13:18:47Z: 000793107.pdf,. Added 1 bitstream(s) on 2015-09-21T13:19:49Z : No. of bitstreams: 1 000793107.pdf: 12638238 bytes, checksum: 2f1c10174d47348f48b14b522ccfb5f7 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No campo da informação, os impactos hodiernos estão relacionados aos avanços da técnica e da tecnologia, com a diversidade de ambientes de informação digital e com a necessidade de lidar com os estoques informacionais que nem sempre se transformam em conhecimento na estrutura cognitiva dos sujeitos. Constatamos a emergência de novas ações teóricas e práticas na disciplina de Arquitetura da Informação, cuja preocupação se fixa na pervasividade da informação em ambientes analógicos, digitais ou híbridos. Estas ações têm utilizado os comportamentos dos sujeitos no cotidiano como elemento norteador para produção de artefatos tecnológicos transparentes ou ubíquos. Evidenciamos que Arquitetura da Informação Pervasiva carece ser melhor concebida no plano conceitual e teórico. Fomos norteados pela seguinte questão de pesquisa: O que é a Arquitetura da Informação Pervasiva e como pode ser representada conceitualmente para tratar as atuais demandas tecnológicas. Traçamos como objetivo geral: Construir um conceito de Arquitetura da Informação Pervasiva com base na fenomenologia e na Ciência da Informação. Defendemos a tese de que sobre a Arquitetura da Informação Pervasiva pode ser feita uma conceituação de base fenomenológica e na perspectiva da Ciência da Informação. Utilizamos o método quadripolar e construímos o polo teórico, o polo epistemológico, o polo técnico e o polo morfológico, incluindo as perspectivas fenomenológica e sistêmica, tratadas como fundamentos epistêmicos da pesquisa e enquadradas no polo epistemológico. Concluímos apresentando teoricamente a Arquitetura da Informação Pervasiva sob a forma de conceito, mapa conceitual e representação visual do conceito, como forma de oferecer mecanismos plurais de disseminação do conceito para alunos, pesquisadores, arquitetos da informação e afins que podem ter preferências cognitivas... / In the information field, the modern-day impacts are related to the advances of the technique and technology, with the diversity of digital information environments and with the need to deal with informational stocks that not always are transformed into knowledge in the subject's cognitive structure. We found the emergence of new theoretical and practical actions in the Information Architecture subject, whose concern is fixed in the information pervasiveness in physical, digital or hybrid environments. These actions have used the subjects' behavior in daily life as a guide for the production of transparent or ubiquitous technological artifacts. We showed that the Pervasive Information Architecture needs to be better designed in conceptual and theoretical level. We were guided by the following research question: What is the Pervasive Information Architecture and how can it be conceptually represented to deal with current technological demands. We draw as general objective: Build a concept of Pervasive Information Architecture based on phenomenology and Information Science. We start from the thesis that on Pervasive Information Architecture a conceptualization with phenomenological basis and in the perspective of Information Science can be made. We use the quadrupole method and construct the theoretical pole, the epistemological pole, the technical pole and the morphological pole, including phenomenological and systemic perspectives, treated as epistemic foundations of research and framed in the epistemological pole. We conclude theoretically presenting Pervasive Information Architecture in the form of concept, conceptual map and visual representation of the concept, as a way to provide plural mechanisms for concept dissemination to students, researchers, information architects and the like, that may have distinct cognitive preferences for knowledge absorption.
26

Jogos em ambientes pervasivos / Games in pervasive environments

Vázquez, Sonia Andrea Lugo January 2009 (has links)
Dispositivos eletrônicos com características de computadores pessoais, como um alto poder de processamento de dados e armazenamento, estão espalhando-se cada vez mais na vida das pessoas. Variando desde notebooks a PocketPCs e, mais recentemente, telefones celulares com funcionalidades extras, os chamados smart phones, estes dispositivos oferecem recursos antes disponíveis apenas em desktops em praticamente qualquer lugar. Essa tendência em difundir cada vez mais serviços computacionais de forma a integrálos na vida das pessoas deu origem à computação pervasiva. Este ramo da computação almeja integrar os serviços computacionais de forma transparente na vida das pessoas. Um uso interessante desta nova tecnologia ainda relativamente pouco explorado é o entretenimento, mais exatamente jogos pervasivos. A criação deste novo tipo de jogo exige que certos cuidados inerentes ao ambiente pervasivo sejam tomados para aumentar a qualidade dos produtos desenvolvidos e permitir que eles de fato resultem na experiência a que se propõe. Este trabalho contribui apresentando uma pesquisa realizada sobre quais são as características desejáveis em jogos pervasivos. Para embasar essas características foi realizado um estudo sobre o que autores clássicos classificam como sendo as características de jogos tradicionais, isto é, jogos que são encontrados no universo físico, sem o auxílio de computadores. Também foram analizados trabalhos que descrevem os elementos usualmente presentes em jogos de video game, que são jogos que utilizam extensivamente recursos computacionais. Utilizando essas duas análises, é possível identificar pontos em comum entre essas duas formas de jogos, e então derivar importantes características que deveriam estar presentes em jogos pervasivos. Um jogo pervasivo foi desenvolvido para verificar se a utilização dessas características aumentam as possibilidades de um jogo pervasivo ser mais fiel ao projeto de seu idealizador. O conceito desse jogo pervasivo é similar ao conceito de um jogo de video game já existente, porém levando em consideração as necessidades do ambiente pervasivo. O jogo foi projetado utilizando as ferramentas de modelagem da UML, respeitando sempre as características quando uma decisão deveria ser tomada. Um protótipo do jogo foi desenvolvido e testado com usuários, sempre procurando avaliar quando as características estavam de fato presentes. Este trabalho finaliza apresentando uma conclusão e algumas possibilidades de trabalhos futuros. / Electronic devices with characteristics of personal computers (such as high processing power and high data storage capacities) are becoming more common in everybody lives. These devices vary from laptops to PocketPCs and, recently, to cell phones with expanded functionality, the so called smart phones. All these equipments make available everywhere possibilities that have been available before only in desktops. This new paradigm of spreading computational services and integrating them into the lives of everybody created the concept of pervasive computing. This branch of computer science aims to integrate computational services transparently into the lives of everyone. An interesting use of this new technology that still has not been widely explored is for entertainment, specifically for pervasive games. The creation of this new type of game demands certain precautions relative to the pervasive environment. This is a necessity, such that the final product has higher quality and actually corresponds to the satisfying experience it proposes. This work contributes by presenting a research about desirable characteristics in pervasive games. A study about the elements of traditional games as classified by classic authors was performed. Traditional games are games that happen in the physical universe, without the use of computers. This work also includes an analysis of different works that describe the characteristics of video games. Video games are games that extensively use computational resources. This work uses both analysis to identify similarities between these two different forms of games, and then builds important characteristics that should be present in pervasive games. A pervasive game has been developed to verify if the use of these characteristics increase the possibilities of a pervasive game meet the design goals set by its designer. The idea behind this pervasive game is similar to the concept of an existing video game, but now considering the requirements of a pervasive environment. This game was designed using the UML tools, always respecting the characteristics when a decision should be made. A prototype of this game was coded and tests have been performed with different users, always trying to verify if the characteristics were indeed present in the game. In the end of this work there is a conclusion section, along with some possibilities for future work.
27

Jogos em ambientes pervasivos / Games in pervasive environments

Vázquez, Sonia Andrea Lugo January 2009 (has links)
Dispositivos eletrônicos com características de computadores pessoais, como um alto poder de processamento de dados e armazenamento, estão espalhando-se cada vez mais na vida das pessoas. Variando desde notebooks a PocketPCs e, mais recentemente, telefones celulares com funcionalidades extras, os chamados smart phones, estes dispositivos oferecem recursos antes disponíveis apenas em desktops em praticamente qualquer lugar. Essa tendência em difundir cada vez mais serviços computacionais de forma a integrálos na vida das pessoas deu origem à computação pervasiva. Este ramo da computação almeja integrar os serviços computacionais de forma transparente na vida das pessoas. Um uso interessante desta nova tecnologia ainda relativamente pouco explorado é o entretenimento, mais exatamente jogos pervasivos. A criação deste novo tipo de jogo exige que certos cuidados inerentes ao ambiente pervasivo sejam tomados para aumentar a qualidade dos produtos desenvolvidos e permitir que eles de fato resultem na experiência a que se propõe. Este trabalho contribui apresentando uma pesquisa realizada sobre quais são as características desejáveis em jogos pervasivos. Para embasar essas características foi realizado um estudo sobre o que autores clássicos classificam como sendo as características de jogos tradicionais, isto é, jogos que são encontrados no universo físico, sem o auxílio de computadores. Também foram analizados trabalhos que descrevem os elementos usualmente presentes em jogos de video game, que são jogos que utilizam extensivamente recursos computacionais. Utilizando essas duas análises, é possível identificar pontos em comum entre essas duas formas de jogos, e então derivar importantes características que deveriam estar presentes em jogos pervasivos. Um jogo pervasivo foi desenvolvido para verificar se a utilização dessas características aumentam as possibilidades de um jogo pervasivo ser mais fiel ao projeto de seu idealizador. O conceito desse jogo pervasivo é similar ao conceito de um jogo de video game já existente, porém levando em consideração as necessidades do ambiente pervasivo. O jogo foi projetado utilizando as ferramentas de modelagem da UML, respeitando sempre as características quando uma decisão deveria ser tomada. Um protótipo do jogo foi desenvolvido e testado com usuários, sempre procurando avaliar quando as características estavam de fato presentes. Este trabalho finaliza apresentando uma conclusão e algumas possibilidades de trabalhos futuros. / Electronic devices with characteristics of personal computers (such as high processing power and high data storage capacities) are becoming more common in everybody lives. These devices vary from laptops to PocketPCs and, recently, to cell phones with expanded functionality, the so called smart phones. All these equipments make available everywhere possibilities that have been available before only in desktops. This new paradigm of spreading computational services and integrating them into the lives of everybody created the concept of pervasive computing. This branch of computer science aims to integrate computational services transparently into the lives of everyone. An interesting use of this new technology that still has not been widely explored is for entertainment, specifically for pervasive games. The creation of this new type of game demands certain precautions relative to the pervasive environment. This is a necessity, such that the final product has higher quality and actually corresponds to the satisfying experience it proposes. This work contributes by presenting a research about desirable characteristics in pervasive games. A study about the elements of traditional games as classified by classic authors was performed. Traditional games are games that happen in the physical universe, without the use of computers. This work also includes an analysis of different works that describe the characteristics of video games. Video games are games that extensively use computational resources. This work uses both analysis to identify similarities between these two different forms of games, and then builds important characteristics that should be present in pervasive games. A pervasive game has been developed to verify if the use of these characteristics increase the possibilities of a pervasive game meet the design goals set by its designer. The idea behind this pervasive game is similar to the concept of an existing video game, but now considering the requirements of a pervasive environment. This game was designed using the UML tools, always respecting the characteristics when a decision should be made. A prototype of this game was coded and tests have been performed with different users, always trying to verify if the characteristics were indeed present in the game. In the end of this work there is a conclusion section, along with some possibilities for future work.
28

Context-aware access control in ubiquitous computing (CRAAC)

Ahmed, Ali Ahmed Ali January 2010 (has links)
Ubiquitous computing (UbiComp) envisions a new computing environment, where computing devices and related technology are widespread (i.e. everywhere) and services are provided at anytime. The technology is embedded discreetly in the environment to raise users' awareness. UbiComp environments support the proliferation of heterogeneous devices such as embedded computing devices, personal digital assistants (PDAs), wearable computers, mobile phones, laptops, office desktops (PCs), and hardware sensors. These devices may be interconnected by common networks (e.g. wired, wireless), and may have different levels of capabilities (i.e. computational power, storage, power consumption, etc). They are seamlessly integrated and interoperated to provide smart services (i.e. adaptive services). A UbiComp environment provides smart services to users based on the users' and/or system's current contexts. It provides the services to users unobtrusively and in turn the user's interactions with the environment should be as non-intrusive and as transparent as possible. Access to such smart services and devices must be controlled by an effective access control system that adapts its decisions based on the changes in the surrounding contextual information. This thesis aims at designing an adaptive fine-grained access control solution that seamlessly fits into UbiComp environments. The solution should be flexible in supporting the use of different contextual information and efficient, in terms of access delays, in controlling access to resources with divergent levels of sensitivity. The main contribution of this thesis is the proposal of the Context-Risk-Aware Access Control (CRAAC) model. CRAAC achieves fine-grained access control based upon the risk level in the underlying access environment and/or the sensitivity level of the requested resource object. CRAAC makes new contributions to the access control field, those include 1) introducing the concept of level of assurance based access control, 2) providing a method to convert the contextual attributes values into the corresponding level of assurance, 3) Proposing two methods to aggregate the set of level of assurance into one requester level of assurance, 4) supporting four modes of working each suits a different application context and/or access control requirements, 5) a comprehensive access control architecture that supports the CRAAC four modes of working, and 6) an evaluation of the CRAAC performance at runtime.
29

DESIGN AND DELIVERY OF A PERVASIVE WEB APPLICATION INTERFACE

PITKIN, SCOTT GARRETT 17 April 2003 (has links)
No description available.
30

Policy-based approach for context-aware systems

Al-Sammarraie, Mohammed January 2011 (has links)
Pervasive (ubiquitous) computing is a new paradigm where the computers are submerged into the background of the everyday life. One important aspect of pervasive systems is context-awareness. Context-aware systems are those that can adapt their behaviours according to the current context. Context-aware applications are being integrated into our everyday activity aspects such as: health care, smart homes and transportations. There exist a wide range of context-aware applications such as: mobile phones, learning systems, smart vehicles. Some context-aware systems are critical since the consequence of failing to identify a given context may be catastrophic. For example, an auto-pilot system is a critical context-aware system; it senses the humidity, clouds, wind speed and accordingly adjusts the altitude, throttle and other parameters. Being a critical context-aware system has to be provably correct. Policy-based approaches has been used in many applications but not in context-aware systems. In this research, we want to discover the anatomy (i.e. architecture, structure and operational behaviour) of policy-based management as applied to context-aware systems, and how policies are managed within such a dynamic system. We propose a novel computational model and its formalisation is presented using the Calculus of Context-aware Ambients (CCA). CCA has been proposed as a suitable mathematical notation to model mobile and context-aware systems. We decided to use CCA due to three reasons: (i) in CCA, mobility and context-awareness are primitive constructs and are treated as first-class citizens; (ii) properties of a system can be formally analysed; (iii) CCA specifications are executable, and thus, leading to rapid prototyping and early validation of the system properties. We, then show how policies can be expressed in CCA. For illustration, the specification of the event-condition-action (ECA) conceptual policy model is modelled in CCA in a natural fashion. We also propose a policy-based architecture for context-aware systems, showing its different components, and how they interact. Furthermore, we give the specification of the policy enforcement mechanism used in our proposed architecture in CCA. To evaluate our approach, a real-world case study of an infostation-based mobile learning (mLearning) system is chosen. This mLearning system is deployed across a university campus to enable mobile users to access mobile services (mServices) represented by course materials (lectures, tests and tutorials) and communication services (intelligent message notification and VoIP). Users can access the mServices through their mobile devices (Hand-set phones, PDAs and laptops) regardless of their device type or location within a university campus. We have specified the mLearning system in CCA (i.e. specification based on policies of the mServices), afterwards, the specification is simulated using the CCA interpreter tool. We have developed an animation tool specially designed for the mLearning system. The animation tool provides graphical representation of the CCA processes. In terms of safety and liveness, some important properties of the mLearning system have been validated as a proof of concept.

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