275 research outputs found

    A Data Annotation Architecture for Semantic Applications in Virtualized Wireless Sensor Networks

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    Wireless Sensor Networks (WSNs) have become very popular and are being used in many application domains (e.g. smart cities, security, gaming and agriculture). Virtualized WSNs allow the same WSN to be shared by multiple applications. Semantic applications are situation-aware and can potentially play a critical role in virtualized WSNs. However, provisioning them in such settings remains a challenge. The key reason is that semantic applications provisioning mandates data annotation. Unfortunately it is no easy task to annotate data collected in virtualized WSNs. This paper proposes a data annotation architecture for semantic applications in virtualized heterogeneous WSNs. The architecture uses overlays as the cornerstone, and we have built a prototype in the cloud environment using Google App Engine. The early performance measurements are also presented.Comment: This paper has been accepted for presentation in main technical session of 14th IFIP/IEEE Symposium on Integrated Network and Service Management (IM 2015) to be held on 11-15 May, 2015, Ottawa, Canad

    Peer - Mediated Distributed Knowledge Management

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    Distributed Knowledge Management is an approach to knowledge management based on the principle that the multiplicity (and heterogeneity) of perspectives within complex organizations is not be viewed as an obstacle to knowledge exploitation, but rather as an opportunity that can foster innovation and creativity. Despite a wide agreement on this principle, most current KM systems are based on the idea that all perspectival aspects of knowledge should be eliminated in favor of an objective and general representation of knowledge. In this paper we propose a peer-to-peer architecture (called KEx), which embodies the principle above in a quite straightforward way: (i) each peer (called a K-peer) provides all the services needed to create and organize "local" knowledge from an individual's or a group's perspective, and (ii) social structures and protocols of meaning negotiation are introduced to achieve semantic coordination among autonomous peers (e.g., when searching documents from other K-peers). A first version of the system, called KEx, is imple-mented as a knowledge exchange level on top of JXTA

    Mobile support in CSCW applications and groupware development frameworks

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    Computer Supported Cooperative Work (CSCW) is an established subset of the field of Human Computer Interaction that deals with the how people use computing technology to enhance group interaction and collaboration. Mobile CSCW has emerged as a result of the progression from personal desktop computing to the mobile device platforms that are ubiquitous today. CSCW aims to not only connect people and facilitate communication through using computers; it aims to provide conceptual models coupled with technology to manage, mediate, and assist collaborative processes. Mobile CSCW research looks to fulfil these aims through the adoption of mobile technology and consideration for the mobile user. Facilitating collaboration using mobile devices brings new challenges. Some of these challenges are inherent to the nature of the device hardware, while others focus on the understanding of how to engineer software to maximize effectiveness for the end-users. This paper reviews seminal and state-of-the-art cooperative software applications and development frameworks, and their support for mobile devices

    A schema-based P2P network to enable publish-subscribe for multimedia content in open hypermedia systems

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    Open Hypermedia Systems (OHS) aim to provide efficient dissemination, adaptation and integration of hyperlinked multimedia resources. Content available in Peer-to-Peer (P2P) networks could add significant value to OHS provided that challenges for efficient discovery and prompt delivery of rich and up-to-date content are successfully addressed. This paper proposes an architecture that enables the operation of OHS over a P2P overlay network of OHS servers based on semantic annotation of (a) peer OHS servers and of (b) multimedia resources that can be obtained through the link services of the OHS. The architecture provides efficient resource discovery. Semantic query-based subscriptions over this P2P network can enable access to up-to-date content, while caching at certain peers enables prompt delivery of multimedia content. Advanced query resolution techniques are employed to match different parts of subscription queries (subqueries). These subscriptions can be shared among different interested peers, thus increasing the efficiency of multimedia content dissemination

    Integrating secure mobile P2P systems and Wireless Sensor Networks

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    Aquesta tesi tracta de les diferents limitacions trobades a WSN per a habilitar-ne el desplegament en nous escenaris i facilitar la difusiĂł de la informaciĂł obtinguda. A un nivell baix, ens centrem en el consum d'energia, mentre que, a un nivell mĂ©s alt, ens focalitzem en la difusiĂł i la seguretat de la informaciĂł. ReduĂŻm el consum d'una mote individual en xarxes amb patrons de trĂ nsit dinĂ mic mitjançant la definiciĂł d'una funciĂł de planificaciĂł basada en el conegut controlador PID i allarguem la vida d'una WSN globalment distribuint equitativament el consum energĂštic de totes les motes, disminuint el nombre d'intervencions necessĂ ries per a canviar bateries i el cost associat. Per tal d'afavorir la difusiĂł de la informaciĂł provinent d'una WSN, hem proposat jxSensor, una capa d'integraciĂł entre les WSN i el conegut sistema P2P JXTA. Com que tractem informaciĂł sensible, hem proposat una capa d'anonimat a JXTA i un mecanisme d'autenticaciĂł lleuger per a la seva versiĂł mĂČbil.Esta tesis trata las diferentes limitaciones encontradas en WSN para habilitar su despliegue en nuevos escenarios, asĂ­ como facilitar la diseminaciĂłn de la informaciĂłn obtenida. A bajo nivel, nos centramos en el consumo de energĂ­a, mientras que, a un nivel mĂĄs alto, nos focalizamos en la diseminaciĂłn y seguridad de la informaciĂłn. Reducimos el consumo de una mota individual en redes con patrones de trĂĄfico dinĂĄmico mediante la definiciĂłn de una funciĂłn de planificaciĂłn basada en el conocido controlador PID y alargamos la vida de una WSN globalmente distribuyendo equitativamente el consumo energĂ©tico de todas las motas, disminuyendo el nĂșmero de intervenciones requeridas para cambiar baterĂ­as y su coste asociado. Para favorecer la diseminaciĂłn de la informaciĂłn procedente de una WSN hemos propuesto jxSensor, una capa de integraciĂłn entre las WSN y el conocido sistema P2P JXTA. Como estamos tratando con informaciĂłn sensible, hemos propuesto una capa de anonimato en JXTA y un mecanismo de autenticaciĂłn ligero para su versiĂłn mĂłvil.This thesis addresses different limitations found in WSNs in order to enable their deployment in new scenarios as well as to make it easier to disseminate the gathered information. At a lower level, we concentrate on energy consumption while, at a higher level, we focus on the dissemination and security of information. The consumption of an individual mote in networks with dynamic traffic patterns is reduced by defining a scheduling function based on the well-known PID controller. Additionally, the life of a WSN is extended by equally distributing the consumption of all the motes, which reduces the number of interventions required to replace batteries as well as the associated cost. To help the dissemination of information coming from a WSN we have proposed jxSensor, which is an integration layer between WSNs and the well-known JXTA P2P system. As we are dealing with sensitive information, we have proposed an anonymity layer in JXTA and a light authentication method in its mobile version

    Araignee Project

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2003.Includes bibliographical references (leaf 56).y Pierre Poignant.S.M

    A lightweight distributed super peer election algorithm for unstructured dynamic P2P systems

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    Dissertação apresentada na Faculdade de CiĂȘncias e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia ElectrotĂ©cnica e de ComputadoresNowadays with the current growth of information exchange, and the increasing mobility of devices, it becomes essential to use technology to monitor this development. For that P2P networks are used, the exchange of information between agencies is facilitated, these now being applied in mobile networks, including MANETs, where they have special features such as the fact that they are semi-centralized, where it takes peers more ability to make a greater role in the network. But those peer with more capacity, which are used in the optimization of various parameters of these systems, such as optimization\to research, are difficult to identify due to the fact that the network does not have a fixed topology, be constantly changing, (we like to go online and offline, to change position, etc.) and not to allow the exchange of large messages. To this end, this thesis proposes a distributed election algorithm of us greater capacity among several possible goals, enhance research in the network. This includes distinguishing characteristics, such as election without global knowledge network, minimal exchange of messages, distributed decision made without dependence on us and the possibility of influencing the election outcome as the special needs of the network

    Collaborative Virtual Environment for Advanced Computing

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    Synchronous collaborative systems allow geographically distributed participants to form a virtual work environment enabling cooperation between peers and enriching the human interaction. The technology facilitating this interaction has been studied for several years and various solutions can be found at present. In this paper, we discuss our experiences with one such widely adopted technology, namely the Access Grid. We describe our experiences with using this technology, identify key problem areas and propose our solution to tackle these issues appropriately. Moreover, we propose the integration of Access Grid with an Application Sharing tool, developed by the authors. Our approach allows these integrated tools to utilise the enhanced features provided by our underlying dynamic transport layer
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