The dream of weaving technology into our everyday fabric of life is recently being made possible by advances in ubiquitous computing and sensor technologies. Countless sensors of various sizes have made their way into everyday commercial applications. Many projects aim to explore new ways to utilize these new technologies to aid and interact with the general population. Context-aware systems use available context information to assist users automatically, without explicit user input. By inferring user intent and configuring the system proactively for each user, context-aware systems are an integral part of achieving user-friendly ubiquitous computing environments. <br /><br /> A common issue with building a distributed context-aware system is the need to develop a supporting infrastructure providing features such as storage, distributed messaging, and security, before the real work on processing context information can be done. This thesis proposes a coordination framework that provides an effective common foundation for context-aware systems. The separation between the context-processing logic component and the underlying supporting foundation allows researchers to focus their energy at the context-processing part of the system, instead of spending their time re-inventing the supporting infrastructure. <br /><br /> As part of an ongoing project, Impress, the framework uses the open standard, Jabber, as its communication protocol. The Publish-Subscribe (pubsub) extension to Jabber provides interesting features that match those needed by a context-aware system. The main contribution of this thesis is the design and implementation of a coordination framework, called the Impress Context Store, that provides an effective common foundation for context-aware systems. The separation between the context-processing logic and the underlying supporting foundation allows researchers to focus their energy at the context-processing part of the system, instead of spending their time re-inventing the supporting infrastructure.

The emergence of pervasive computing power and networking infrastructure is enabling new applications. Still, many milestones need to be reached before pervasive computing becomes an integral part of our lives. An important missing piece is the middleware that allows developers to easily create interesting pervasive computing applications. This dissertation explores the middleware needs of distributed pervasive applications. The main contributions of this thesis are the design, implementation, and evaluation of two systems: D-Stampede and Crest. D-Stampede allows pervasive applications to access live stream data from multiple sources using time as an index. Crest allows applications to organize historical events, and to reason about them using time, location, and identity. Together they meet the important needs of pervasive computing applications. D-Stampede supports a computational model called the thread-channel graph. The threads map to computing devices ranging from small to high-end processing elements. Channels serve as the conduits among the threads, specifically tuned to handle time-sequenced streaming data. D-Stampede allows the dynamic creation of threads and channels, and for the dynamic establishment (and removal) of the plumbing among them. The Crest system assumes a universe that consists of participation servers and event stores, supporting a set of applications. Each application consists of distributed software entities working together. The participation server helps the application entities to discover each other for interaction purposes. Application entities can generate events, store them at an event store, and correlate events. The entities can communicate with one another directly, or indirectly through the event store. We have qualitatively and quantitatively evaluated D-Stampede and Crest. The qualitative aspect refers to the ease of programming afforded by our programming abstractions for pervasive applications. The quantitative aspect measures the cost of the API calls, and the performance of an application pipeline that uses the systems.

In this thesis work, a certificate based authentication model supported by mobile devices is provided for ubiquitous computing environments. The model primarily aims to create an infrastructure for controlling and regulating access requests through mobile devices to local resources and services. The model also allows users from different domains to use local resources and services within the scope of agreements between domains. In addition to conceptual description of the model, a real prototype implementation is developed and successful application of the model is demonstrated. Within the prototype implementation, a mobile application is developed for access requests and sensors are used as representative local resources. Sample cases applied on the prototype demonstrate applicability and feasibility of the model.

Significant developments in microprocessor and sensor technology make wirelessly connected small computing devices widely available / hence they are being used frequently to collect data from the environment. In this study, we construct a framework in order to extract high level information in an environment containing such pervasive computing devices. In the framework, raw data originating from wireless sensors are collected using an event driven system and converted to simple events for transmission over a network to a central processing unit. We also utilize complex event processing approach incorporating temporal constraints, aggregation and sequencing of events in order to define complex events for extracting high level information from the collected simple events. We develop a prototype using easily accessible hardware and set it up in a classroom within our university. The results demonstrate the feasibility of our approach, ease of deployment and successful application of the complex event processing framework.

Delivering accurate and opportune information on people's activities and behaviors has become one of the most important tasks within pervasive computing. Its wide spectrum of potential applications in medical, entertainment, and tactical scenarios, motivates further research and development of new strategies to improve accuracy, pervasiveness, and eciency. This dissertation addresses the recognition of human activities (HAR) with wearable sensors in three main regards: In the rst place, physiological signals have been incorporated as a new source of information to improve the recognition accuracy achieved by conventional approaches, which rely on accelerometer signals solely. A new HAR system, Centinela, was born from such concept, employing structural feature extraction along with classier ensembles, and achieving over 95% of recognition accuracy. In the second place, real time activity recognition was enabled by Vigilante, a mobile HAR framework under the AndroidTM platform. Providing immediate feedback on the user's activities is especially benecial in healthcare and military applications, which may require alert triggering or support of decision making. The evaluation demonstrates that Vigilante is energy ecient while maintaining high accuracy (i.e., up to 96.8%) and low response time. The system features MECLA, a mobile library for the evaluation of classification algorithms, which is also suitable for further machine learning applications. Finally, the activity recognition accuracy is improved by two new strategies for decision fusion and selection in multiple classier systems: the failure product and the precision-recall dierence. The experimental analysis conrms that the presented methods are benecial, not only for recognizing human activities, but also for many other classication problems.

Pervasive computing or ambient computing aims to integrate information systems into the environment, in a manner as transparent as possible to the users. It allows the information systems to be tightly coupled with the physical activities within the environment. Everyday used objects, along with their environment, are made smarter with the use of embedded computing, sensors etc. and also have the ability to communicate among themselves. In pervasive computing, it is necessary to sense the real physical world and to perceive its "context" ; a high level representation of the physical situation. There are various ways to derive the context. Typically, the approach is a multi-step process which begins with sensing. Various sensing technologies are used to capture low level information of the physical activities, which are then aggregated, analyzed and computed elsewhere in the information systems, to become aware of the context. Deployed applications then react, depending on the context situation. Among sensors, RFID is an important emerging technology which allows a direct digital link between information systems and physical objects. Besides storing identification data, RFID also provides a general purpose storage space on objects, enabling new architectures for pervasive computing. In this thesis, we defend an original approach adopting the later use of RFID i.e. a digital memory integrated to real objects. The approach uses the principle where the objects self-support information systems. This way of integration reduces the need of communication for remote processing. The principle is realized in two ways. First, objects are piggybacked with semantic information, related to itself ; as self-describing objects. Hence, relevant information associated with the physical entities are readily available locally for processing. Second, group of related objects are digitally linked using dedicated or ad-hoc data structure, distributed over the objects. Hence, it would allow direct data processing - like validating some property involving the objects in proximity. This property of physical relation among objects can be interpreted digitally from the data structure ; this justifies the appellation "Tangible Data Structures". Unlike the conventional method of using identifiers, our approach has arguments on its benefits in terms of privacy, scalability, autonomy and reduced dependency with respect to infrastructure. But its challenge lies in the expressivity due to limited memory space available in the tags. The principles are validated by prototyping in two different application domains. The first application is developed for waste management domain that helps in efficient sorting and better recycling. And the second, provides added services like assistance while assembling and verification for composite objects, using the distributed data structure across the individual pieces.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-18T16:32:06Z No. of bitstreams: 1 PAULO VICTOR SILVA OURIQUES - DISSERTAÇÃO PPGCC 2014..pdf: 15529498 bytes, checksum: 878a0f70f377ee9edf9e0347c482a19b (MD5) / Made available in DSpace on 2018-04-18T16:32:06Z (GMT). No. of bitstreams: 1 PAULO VICTOR SILVA OURIQUES - DISSERTAÇÃO PPGCC 2014..pdf: 15529498 bytes, checksum: 878a0f70f377ee9edf9e0347c482a19b (MD5) Previous issue date: 2014-02-15 / A Propaganda Pervasiva diferencia-se das demais formas de veiculação de anúncios por permitir a entrega responsiva ao contexto dos consumidores. Dessa forma, é possível entregar aos consumidores os anúncios mais relevantes, proporcionando maior efetividade à campanha publicitária. Atualmente, os sistemas de entrega de anúncios apenas levam em consideração a relevância do anúncio para o cliente, não se preocupando com a maneira com a qual esses anúncios serão exibidos e nem com a influência causada por essa forma de exibição na relevância do anúncio. Sendo assim, objetiva-se neste trabalho elaborar um mecanismo que permita exibir um anúncio ao consumidor através do canal de veiculação mais apropriada. Para isso,é preciso que este mecanismo leve em consideração a influência que o canal de veiculação exerce sobre a relevância do anúncio e qual o propósito da campanha publiciária à qual pertence o anúncio. Tendo esta infraestrutura desenvolvida, será muito mais fácil elaborar mecanismos de avaliação da campanha publicitária levando em consideração a forma de exibição dos anúncios. Estes mecanismos poderão indicar qual o canal de veiculação que mais impactou o cliente, qual a que obteve maior audiência, qual foi a mais indicada, etc. Para validar os modelos desenvolvidos, foram realizadas baterias de experimentos com foco no impacto do tempo de resposta de um canal de veiculação na relevância do anúncio. A análise dos resultados permite mostrar que é possível sim utilizar o tempo de resposta para escolher o canal mais adequando para veicular um anúncio, assegurando-se que o propósito da campanha publicitária seja satisfeito. / Pervasive Advertising differs from other forms of ad serving because allows responsive delivery to the consumer context. Thus, it’s possible to deliver to consumers the most relevant ads, providing greater effectiveness to advertising campaign. Nowadays the delivering ads systems only consider the relevance of the ad to the client, not worrying about the way those ads are displayed and ignoring the influence caused by this form of display in ad relevance. Thus, the objective of this work is develop a mechanism that shows an ad to the consumer through the most appropriate display interface. For this,the mechanism must to consider the influence that the interface exerts on relevance of the ad. Whith this infrastructure, will be much easier to develop mechanisms for evaluating the hype,considering the way of delivering ads. These mechanisms may indicate the display interface that most impacted the user, which obtained larger audience, which was better indicated, etc. To validate the developed models, experiments focusing on the impact the response time of a channel broadcasting in ad relevance were held. The result analysis shows that it’s possible to use the response time to choose the channel ad serving, ensuring that the purpose of the advertising campaign is satisfied.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-08-06T17:16:31Z No. of bitstreams: 1 LUCAS VIERA DE SOUZA - DISSERTAÇÃO PPGCC 2012..pdf: 7997009 bytes, checksum: e5aaa6bb999df33f4638781b37b9dde5 (MD5) / Made available in DSpace on 2018-08-06T17:16:31Z (GMT). No. of bitstreams: 1 LUCAS VIERA DE SOUZA - DISSERTAÇÃO PPGCC 2012..pdf: 7997009 bytes, checksum: e5aaa6bb999df33f4638781b37b9dde5 (MD5) Previous issue date: 2012-02-29 / Capes / O avanço dos recursos computacionais dos aparelhos portáteis e a convergência de novas funcionalidades nestes dispositivos, tem criado novas oportunidades para o universo da computação pervasiva. Esses novos atributos, aliados a facilidade de conectividade entre eles e a disponibilização de serviços móveis, tem motivado o compartilhamento e a bilhetagem de recursos entre os usuários desses dispositivos. São exemplos de serviços: o compartilhamento de conteúdo multimídia, o controle de equipamentos eletrônicos e eletrodomésticos, o acesso à Internet, entre outros. Os aplicativos móveis que oferecem a bilhetagem de recursos, em sua maioria, apresentam apenas formas de cobrança online, com necessidade de uma conexão com a internet para a validação das transações. ne, com a necessidade de uma conexão com a Internet para a validação das transações. Outras aplicações apresentam uma forma de cobrança offline, porém são soluções que necessitam de um hardware específico para o seu funcionamento, o que inviabiliza a adoção de diversos dispositivos já presentes no mercado. Tendo em vista esses aspectos, neste trabalho é apresentada uma infraestrutura para o desenvolvimento de aplicações com suporte a bilhetagem em modo offline e sem a necessidade de um hardware específico para seu funcionamento. A validação do trabalho foi realizada a partir da implementação de um estudo de caso de um serviço de envio de mensagens SMS, que encaminha mensagens texto para dispositivos celulares a partir da transferência de arquivos, demonstrando o suporte oferecido pela infraestrutura para o desenvolvimento de aplicações móveis que oferecem bilhetagem de recursos. / The improvement of computational resources of mobile devices and the convergence of new features in these devices has created new opportunities for the world of pervasive computing. These new attributes, combined with ease of connectivity between them and the provision of mobile services has motivated the sharing of resources and billing between the users of these devices. Examples of services: the sharing of multimedia content, the electronics control and appliances, Internet access, others. Mobile applications that offer resource billing, most of them, have only online charging, with the need of an Internet connection to validate transactions. Other applications presents offline charging, but they are solutions that require specific hardware for its operation, which prevents the adoption of devices already on the market. Considering these aspects, this work presents an infrastructure for developing applications that supports service billing, which offers a new way of charging. The infrastructure allows billing in offline mode without the need for specific hardware to function. The work validation was performed by implementing a case study of a service for sending SMS messages, which sends text messages to mobile phones through file transfer, showing the support offered by the infrastructure for the development of mobile applications that provide the service billing.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-07-30T15:07:27Z No. of bitstreams: 1 OLYMPIO CIPRIANO DA SILVA FILHO - DISSERTAÇÃO PPGEE 2007..pdf: 1354330 bytes, checksum: 4271b1c8fe8556d562518fb586e85376 (MD5) / Made available in DSpace on 2018-07-30T15:07:27Z (GMT). No. of bitstreams: 1 OLYMPIO CIPRIANO DA SILVA FILHO - DISSERTAÇÃO PPGEE 2007..pdf: 1354330 bytes, checksum: 4271b1c8fe8556d562518fb586e85376 (MD5) Previous issue date: 2007-12-14 / Com o desenvolvimento tecnológico a computação está cada vez mais integrada ao cotidiano das pessoas. Esta integração faz parte de um novo paradigma da computação: o da Computação Pervasiva. Neste paradigma, a computação está sempre a disposição do usuário, em qualquer lugar, a qualquer momento, através de ambientes repletos de dispositivos computacionais embutidos em uma grande variedade de objetos do dia-a-dia das pessoas como, automóveis, telefones, etc. Nestes ambientes, os dispositivos interagem entre si através de serviços devendo ser capazes lidar com a grande variedade de protocolos de descoberta de serviços disponíveis. Ainda,essas interações entre os dispositivos podem ocorrer em ambientes sem infra-estrutura de redes de computadores e entre dispositivos que podem agir desonestamente. Neste trabalho, é desenvolvido um modelo para avaliar a confiança nos serviços nos ambientes pervasivos a partir de experiências e recomendações. Este modelo é implementado por um Gerenciador de Informação de Confiança o qual disponibiliza um mecanismo de tomada de decisão para realizar a seleção de clientes e provedores de serviço. Ainda, o Gerenciador de Informação de Confiança é integrado a um middleware para computação pervasiva, o Wings, possibilitando a descoberta de serviços confiáveis. Foram utilizadas simulações e uma aplicação de teste para avaliar o Gerenciador de Informação de Confiança e sua integração ao middleware Wings. A partir dos resultados obtidos observou-se que a solução apresentada se mostrou satisfatória para a utilização em ambientes pervasivos. / The development of technology is integrating computing to people every day life. This integration belongs to a new computing paradigm: the pervasive computing. In this paradigm, the computation is always available, in every place at any time, through environments crowd of computing devices embedded in a great variety of objects like cars,cell phones, etc. In these environments, devices interact through services and should be able to deal with different service announcement solutions available. These interactions can occur without computing network infrastructure andamong malicious devices. In this work, it is developed a model to evaluate service trust in pervasive environments from experiences and recommendations. This model is implemented by a Trust Information Manager that provides a mechanism to make trust based decision. This Trust Information Manager is integrated to a pervasive computing middle ware,called Wings, enabling trusted service discover. Simulations and a test application were used to evaluate theTrust Information Manager and its integration with the Wings middleware. From the results it could be seen that the presented solution is efficient and can be widely used in pervasive computing environments.

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