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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.
521

Personal Informatics and Context: Using Context to Reveal Factors that Affect Behavior

Li, Ian Anthony Rosas 01 August 2011 (has links)
Personal informatics systems help people collect and reflect on behavioral information to better understand their own behavior. Because most systems only show one type of behavioral information, finding factors that affect one’s behavior is difficult. Supporting exploration of multiple types of contextual and behavioral information in a single interface may help. To explore this, I developed prototypes of IMPACT, which supports reflection on physical activity and multiple types of contextual information. I conducted field studies of the prototypes, which showed that such a system could increase people’s awareness of opportunities for physical activity. However, several limitations affected the usage and value of these prototypes. To improve support for such systems, I conducted a series of interviews and field studies. First, I interviewed people about their experiences using personal informatics systems resulting in the Stage-Based Model of Personal Informatics Systems, which describes the different stages that systems need to support, and a list of problems that people experience in each of the stages. Second, I identified the kinds of questions people ask about their personal data and found that the importance of these questions differed between two phases: Discovery and Maintenance. Third, I evaluated different visualization features to improve support for reflection on multiple kinds of data. Finally, based on this evaluation, I developed a system called Innertube to help people reflect on multiple kinds of data in a single interface using a visualization integration approach that makes it easier to build such tools compared to the more common data integration approach.
522

The context-aware middleware in ambient intelligence

Xu, Tao 09 December 2013 (has links) (PDF)
Almost 20 years ago, Marc Weiser envisioned the prospect of computer in 21st century, and proposed the pioneering notion of ubiquitous computing. One of Weiser's primary ideas has recently evolved to a more general paradigm known as context awareness, becoming a central research theme in many other ubiquitous computing programs. From Active Badge considered as the first context-aware application, there are numerous attempts to build effective context-aware systems. However, how to acquire context, how to process context and how to create context-aware applications is still faced with enormous challenges in the both of research and practice. This dissertation investigates deeply some chosen key issues in context awareness and develops a context-aware middleware. The main research contributions are presented in three categories: a spatialtemporal context represent model, a context-aware middleware and an intelligence context inference engine. The spatial-temporal context representation model is proposed to organize context and relations for context-aware system. Ontology-based method is adopted to construct our model, supporting both knowledge sharing and reuse as well as logic inference. This model adopts two-layer hierarchy structure for different situation. The higher layer comes up with the generic common context, while the lower layer focuses on various specific situations. Differing from existing models, besides taking locational factors into account, it supports different historical context service depending on different context resource. These context histories may be used to predict and infer the context. A context-aware middleware is designed as a platform associated with context retrieval and context processing. It is organized in two layers: the low layer provides a solution to integrate sensors and actuators with a standardized data representation; the high layer: versatile context interpreter focuses on context processing, which is made up of four parts: Context Aggregator, Inference Engine, Context Knowledge Base, and Query Engine in charge of context inferences, expressive query, and persistent storage. This middleware provides an environment for rapid prototyping of context aware services in ambient intelligent. The intelligent inference engine is the central and intellectual component of context-aware middleware. We review all the methods on activity context recognition published in three premier conferences in past decade and conclude that activity context recognition is divided into three facets: basic activity inference, dynamic activity analysis and future activity recommendation. Then we propose an intelligent inference engine based on our context-aware middleware. Beside satisfying requirements of checking the context consistency, our inference engine integrates the three most popular methods on activity context recognition: Rules, Decision Tree, and Hide Markov Model. It provides a solution for all facets of activity context recognition based on our context-aware middleware. The individuals' information collecting from their social networks under permission are leveraged to train intelligent inference engine. We finally use two scenarios (applications) to explain the generic process to develop application via our middleware, and compare and analyze the main aspects of our middleware with other five representative context-aware applications. Our middleware profits good features from existing context-aware systems and improve intelligence via supporting activity context recognition. It provides an efficient platform for a rapid developing of new context-aware applications in ambient intelligence.
523

Auto-configuration, supervision et contrôle d'entités physiques par l'intermédiaire de réseaux de capteurs et actionneurs

HU, Zheng 22 January 2014 (has links) (PDF)
Les entités physiques prises en compte par les applications dites M2M dans les télécoms sont aujourd'hui de plus en plus hétérogènes. Le défi adressé par ce travail est donc l'intégration, et la configuration automatiques de toutes ces différentes variétés d'entités physiques d'une façon homogène dans les systèmes M2M, en généralisant les approches de configuration automatique déjà connues et utilisées pour les objets communicants numériques. Cette thèse présente un cadre théorique général et des mécanismes de base pour l'identification de modèles de telles entités physiques dans les systèmes d'information embarqués répartis, en englobant dans une même approche les équipements et les sous-ensembles de l'espace, faisant se rejoindre les points de vue "internet des objets" et "environnement interactif" dans une nouvelle vision unifiée de l'intelligence ambiante. Ce travail, motivé initialement par les applications à la gestion d'énergie domestique, cherche à intégrer au réseau local de la maison des entités physiques qui ont un impact énergétique mais ne sont dotés d'aucune connexion réseau, ce qui correspond à une extension qualitative du périmètre de l'Internet des Objets. Cette intégration se fait de manière tout à fait similaire à ce qui est fait classiquement pour des équipements numériques état de l'art, c'est-à-dire par des mécanismes de découverte et configuration spontanés. Ces mécanismes comportent les étapes suivantes : détection de la présence d'une entité physique par analyse de la coïncidence d'évènements significatifs reçus de capteurs ; sélection d'un premier modèle générique représentatif de l'entité physique détectée depuis une ontologie de référence en analysant des données reçues les capteurs ; création d'un composant logiciel représentant l'entité physique détectée, à partir du modèle sélectionné, et associant les capteurs et actionneurs utiles ; supervision et contrôle de l'entité cible par l'intermédiaire de ce composant logiciel ; mise à jour incrémentale du modèle de l'entité identifiée par analyse des données issues des capteurs associés. Ce travail est parti d'applications dans l'environnement de la maison, pour lesquelles il a été validé et mis en œuvre. Mais notre approche a vocation à être généralisée et étendue à des environnements comme les bâtiments ou la ville, en offrant suivant le même principe une infrastructure partagée pour toutes les applications M2M dans ces environnements
524

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.
525

Extending a networked robot system to include humans, tiny devices, and everyday objects

Rashid, Md. Jayedur January 2011 (has links)
In networked robot systems (NRS), robots and robotic devices are distributed in the environment; typically tasks are performed by cooperation and coordination of such multiple networked components. NRS offer advantages over monolithic systems in terms of modularity, flexibility and cost effectiveness, and they are thus becoming a mainstream approach to the inclusion of robotic solutions in everyday environments. The components of a NRS are usually robots and sensors equipped with rich computational and communication facilities. In this thesis, we argue that the capabilities of a NRS would greatly increase if it could also accommodate among its nodes simpler entities, like small ubiquitous sensing and actuation devices, home appliances, or augmented everyday objects. For instance, a domestic robot needs to manipulate food items and interact with appliances. Such a robot would benefit from the ability to exchange information with those items and appliances in a direct way, in the same way as with other networked robots and sensors. Combining such highly heterogeneous devices inside one NRS is challenging, and one of the major challenges is to provide a common communication and collaboration infrastructure. In the field of NRS, this infrastructure is commonly provided by a shared middleware. Unfortunately, current middlewares lack the generality needed to allow heterogeneous entities such as robots, simple ubiquitous devices and everyday objects to coexist in the same system. In this thesis we show how an existing middleware for NRS can be extended to include three new types of “citizens” in the system, on peer with the other robots. First, we include computationally simple embedded devices, like ubiquitous sensors and actuators, by creating a fully compatible tiny version of the existing robotic middleware. Second, we include augmented everyday objects or home appliances which are unable to run the middleware on board, by proposing a generic design pattern based on the notion of object proxy. Finally,we go one step further and include humans as nodes in the NRS by defining the notion of human proxy. While there exist a few other NRS which are able to include both robots and simple embedded devices in the same system, the use of proxies to include everyday objects and humans in a generic way is a unique feature of this work. In order to verify and validate the above concepts, we have implemented them in the Peis-Ecology NRS model. We report a number of experiments based on this implementation, which provide both quantitative and qualitative evaluations of its performance, reliability, and interoperability.
526

Operationalization of collaborative blended learning scripts: a model, computational mechanisms and experiments

Pérez Sanagustín, Maria del Mar 01 July 2011 (has links)
Portable and interactive technologies are changing the nature of collaborative learning practices. Learning can now occur both in and beyond the classroom and furthermore combine formal and informal activities monitored and orchestrated across spatial locations. This rises to a new type of orchestrated learning that we term Computer Supported Collaborative Blended Learning (CSCBL) scripts. This thesis investigates the challenges associated with the design of CSCBL scripts and with the technologies responsible for their enactment. Three contributions are presented. First, a conceptual model that combines 4 factors to be considered in the design of CSCBL scripts. Second, technological solutions operationalizing the aforementioned factors are proposed and evaluated through synthetic experiences. And third, four CSCBL experiments using 4SPPIces. These experiments are analyzed into two interrelated multicase case studies, whose cross-analyzed results provide an evaluation of the model, of the operationalization solutions supporting the enactment of the involved CSCBL scripts and of the educational value of the experiences themselves. / La introducción de tecnologías interactivas y móviles está produciendo un cambio significativo en la naturaleza de las prácticas educativas. Actualmente, el aprendizaje mediante colaboración se puede dar en situaciones en que secuencias de actividades formales e informales dentro y fuera del aula se combinan e integran de forma coordinada. Esto da lugar a un nuevo tipo de actividades de colaboración orquestadas en entornos mezclados que llamaremos guiones CSCBL (de su acrónimo en inglés). Esta tesis investiga los retos relacionados con diseño de los guiones CSCBL y de la selección apropiada de la tecnología para su puesta en marcha. De este trabajo de investigación se derivan tres contribuciones principales. Primero, se propone un modelo conceptual que combina 4 factores a tener en cuenta en el diseño de guiones CSCBL. Segundo, se proponen un conjunto de soluciones tecnológicas para dar soporte computacional a los diferentes factores del modelo y dar apoyo a la puesta en marcha de guiones CSCBL. Cada una de estas soluciones se evalúa mediante experimentos sintéticos. Finalmente, esta tesis presenta tres experimentos en que se usa el modelo para proponer actividades de colaboración en entornos mezclados y aplicarlas en entornos reales. Estos experimentos han sido evaluados mediante dos estudios múltiples de casos. El análisis cruzado de los resultados de los casos englobados en cada estudio ofrece una evaluación de la utilidad del modelo y de las soluciones tecnológicas adoptadas para su puesta en marcha.
527

Network mobility management for next generation mobile systems

Perera, Algamakoralage Eranga Gayani, Electrical Engineering & Telecommunications, Faculty of Engineering, UNSW January 2007 (has links)
The future Internet will need to cater for an increasing number of powerful devices and entire groups of networks to roam in heterogeneous access networks. The current approach towards meeting such requirements, which is to retrofit mobility solutions to different layers of the protocol stack, has given rise to an increasingly fragmented network control layer. Furthermore, retrofitting solutions in an ad-hoc manner to the protocol stack does not provide consistent support from the network to different applications. This lack of a common control layer for facilitating roaming in heterogeneous networking environments represents a crucial challenge both technically and from a user perspective. To this end, a novel mobility architecture forms the basis and the first part of this dissertation. The work on investigating current network mobility solutions and improving these solutions if deemed necessary, in order to reuse within the novel mobility architecture constitutes the second part of this dissertation. The IETF standard protocol for network mobility was implemented and its performance was analysed on a real networking environment. This enabled to identify problems in the standard which affect the handover and routing performance. To address the identified routing and protocol header overheads of the standard network mobility protocol a novel optimal routing framework, OptiNets was proposed. To address the handover latency issues, optimizations to IPv6 network attachment were incorporated and also an access technology independent multiple interface Make-Before-Break handover mechanism was proposed. The viability of the OptiNets framework and the handover optimizations were demonstrated by analysis and by implementation. A more general external factor that affects the performance of mobile networks which is bandwidth scarcity of Wireless Wide Area Networks was addressed, by proposing a bandwidth fuelling architecture for on-board mobile networks. The feasibility of the bandwidth fuelling architecture was analysed by implementing a prototype and evaluating its performance.
528

Smart Devices as U-Learning Tools: Key Factors Influencing Users’ Intention

Aziz, Najibullah January 2015 (has links)
There was a lack of knowledge about the user’s acceptance of smart devices as ubiquitous learning (u-learning) tools at higher education institutions in Sweden. As the mobile technology grows, the demand for mobile devices, particularly smart devices increases as well. With the increase in the usage of smart devices, the higher education institutions provide mobile learning platforms to attract more customers in the competitive industry of education. Thus, understanding the key factors from the perspectives of end-users is important for the institutions to survive in the competitive market. This study explores and explains Behavioral and Continuance intentions of students regarding the acceptance and usage of smart devices (Smartphones and Personal Digital Assistants or PDA) as u-learning tools. Key factors related to the users’ intentions to accept and continue using smart devices as u-learning tools were identified and hypothesized in the Swedish context. Ten hypotheses were suggested based on TAM, UTAUT, and ECT. To achieve the aim and objective of this study, a quantitative approach was chosen, and a survey strategy based on purposive and convenience sampling techniques were used. A web-based questionnaire on five-points Likert Scale was designed to collect the required data. 115 (96 valid) students answered the questionnaire. The collected data were used to conduct statistical operations in SPSS. Five hypotheses were supported, and the other five were not. The findings suggest that Performance Expectancy, Perceived Mobility value, Confirmation, and Satisfaction positively influence both Behavioral and Continuance Intentions of students to accept and continue using smart devices as u-learning tools. According to the findings, Confirmation and Satisfaction from ECT can be included as separate constructs in UTAUT and UTAUT2. Higher education institutions planning to have (and those that already have) learning platforms, compatible with smart devices, can benefit from the findings. Higher education institutions can also design their u-learning platforms according to the Performance Expectancy, Perceived Mobility value, Confirmation, and Satisfaction of the students. / Master program in Strategic-IT Management
529

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.
530

UMA ARQUITETURA PARA A UTILIZAÇÃO DE COMPUTAÇÃO NAS NUVENS NOS AMBIENTES DE COMPUTAÇÃO PERVASIVA / AN ARCHITECTURE FOR THE USE OF CLOUD COMPUTING IN PERVASIVE COMPUTING ENVIRONMENTS

Pereira, Henrique Gabriel Gularte 22 March 2012 (has links)
The modern world can be characterized by the quick proliferation of mobile devices and by the intense use of computers on our daily lives. Both pervasive computing and cloud computing have appeared as very promissing trends, but for pervasive computing to reach mainstream, many paradigm changes are needed on the current computing environments. Some of the problems found in pervasive camputing are not from a technical order, but due to a lack of standards and models to allow devices to interoperate and the problems related to the creation of low cost computing environments. Pervasive environments are marked by having sudden and frequent changes, making it necessary to think of a way to manage context information. This work aims at showing a solution that will allow the creation of pervasive computing environments using resources available in the cloud computing paradigm and taking in consideration requisites like the ability of mixing heterogenous computing devices running on the least possible amount of resources and using ontologies for context information representation and management. In this context, an architecture for the development of pervasive computing environments, an study case in a residencial cenario and an analysis of the results obtained with the proposed architecture are presented. / O mundo atual é caracterizado pela rápida proliferação de dispositivos móveis e pelo intenso uso de computadores no nosso cotidiano. Tanto a computação pervasiva quanto a computação em nuvem têm surgido como uma tendência muito promissora. Porém, para que a computação pervasiva se consolide são necessárias algumas mudanças de paradigma nos ambientes atuais da computação. Boa parte dos problemas encontrados hoje em dia na computação pervasiva não são de ordem técnica, mas sim a falta de padrões e modelos para permitir a interoperabilidade entre os dispositivos e a criação de ambientes computacionais de baixo custo. Os ambientes de computação pervasiva são caracterizados por mudanças rápidas e frequentes, sendo necessária a existência de alguma maneira para gerenciar essa informação de contexto. Essa dissertação visa apresentar uma solução para permitir a criação de ambientes de computação pervasiva utilizando serviços disponíveis no paradigma da computação em nuvem levando em consideração requisitos como a capacidade de trabalhar com dispositivos computacionais heterogêneos consumindo o mínimo possível de recursos e utilizando ontologias para a representação de informação de contexto. Nesse contexto, são apresentadas uma proposta de arquitetura para ambientes pervasivos, um estudo de caso em um cenário residencial e apresentados resultados e conclusões sobre a arquitetura proposta. Os resultados alcançados no estudo de caso permitiram a implementação de um ambiente pervasivo utilizando recursos computacionais disponíveis na nuvem e atingind os objetivos propostos no trabalho.

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