8 research outputs found

    \A Ro- bust Node Selection Strategy for Lifetime Extension in Wireless Sensor Networks

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    Distributed Wireless Sensor Networks (WSNs) consist of energy-constrained sensor nodes that may be deployed in large numbers in order to monitor a given area, track military targets, detect civilian targets or for other purposes. In such densely deployed environments, multiple transmissions can lead to collisions resulting in packet losses and network congestion. This can increase latency and reduce energy efficiency. These networks also feature significant redundancy since nodes close to each other often sense similar data. Therefore, it may be adequate to employ only a subset of the deployed nodes at any given time in the network. In this thesis, node subsets are selected in a manner that coverage and connectivity are consistently achieved. The working subsets are changed after predetermined durations. A framework using concepts from spatial statistics is developed as an approach to selecting the subset of sensor nodes. Proximal nodes negotiate with each other using energy information, to decide which nodes stay working while others go to sleep mode. The algorithm is executed autonomously by the network. The approach presented ensures that the selected subsets while not necessarily exclusive of previous selections covers the region of interest. Simulation results show that the algorithm is robust and retains some level of redundancy. The algorithm shows significant improvement in energy consumption compared with a network with no selection. The selected subset is shown to be able to withstand significant levels of fault in the network. Conclusions regarding the flexibility and application scenarios of the algorithm are drawn and opportunities for future work indicated

    Smart Monitoring and Control in the Future Internet of Things

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    The Internet of Things (IoT) and related technologies have the promise of realizing pervasive and smart applications which, in turn, have the potential of improving the quality of life of people living in a connected world. According to the IoT vision, all things can cooperate amongst themselves and be managed from anywhere via the Internet, allowing tight integration between the physical and cyber worlds and thus improving efficiency, promoting usability, and opening up new application opportunities. Nowadays, IoT technologies have successfully been exploited in several domains, providing both social and economic benefits. The realization of the full potential of the next generation of the Internet of Things still needs further research efforts concerning, for instance, the identification of new architectures, methodologies, and infrastructures dealing with distributed and decentralized IoT systems; the integration of IoT with cognitive and social capabilities; the enhancement of the sensing鈥揳nalysis鈥揷ontrol cycle; the integration of consciousness and awareness in IoT environments; and the design of new algorithms and techniques for managing IoT big data. This Special Issue is devoted to advancements in technologies, methodologies, and applications for IoT, together with emerging standards and research topics which would lead to realization of the future Internet of Things

    Advances in Information Security and Privacy

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    With the recent pandemic emergency, many people are spending their days in smart working and have increased their use of digital resources for both work and entertainment. The result is that the amount of digital information handled online is dramatically increased, and we can observe a significant increase in the number of attacks, breaches, and hacks. This Special Issue aims to establish the state of the art in protecting information by mitigating information risks. This objective is reached by presenting both surveys on specific topics and original approaches and solutions to specific problems. In total, 16 papers have been published in this Special Issue

    Design and Evaluation of Low-Latency Communication Middleware on High Performance Computing Systems

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    [Resumen]El inter茅s en Java para computaci贸n paralela est谩 motivado por sus interesantes caracter铆sticas, tales como su soporte multithread, portabilidad, facilidad de aprendizaje,alta productividad y el aumento significativo en su rendimiento omputacional. No obstante, las aplicaciones paralelas en Java carecen generalmente de mecanismos de comunicaci贸n eficientes, los cuales utilizan a menudo protocolos basados en sockets incapaces de obtener el m谩ximo provecho de las redes de baja latencia, obstaculizando la adopci贸n de Java en computaci贸n de altas prestaciones (High Per- formance Computing, HPC). Esta Tesis Doctoral presenta el dise帽o, implementaci贸n y evaluaci贸n de soluciones de comunicaci贸n en Java que superan esta limitaci贸n. En consecuencia, se desarrollaron m煤ltiples dispositivos de comunicaci贸n a bajo nivel para paso de mensajes en Java (Message-Passing in Java, MPJ) que aprovechan al m谩ximo el hardware de red subyacente mediante operaciones de acceso directo a memoria remota que proporcionan comunicaciones de baja latencia. Tambi茅n se incluye una biblioteca de paso de mensajes en Java totalmente funcional, FastMPJ, en la cual se integraron los dispositivos de comunicaci贸n. La evaluaci贸n experimental ha mostrado que las primitivas de comunicaci贸n de FastMPJ son competitivas en comparaci贸n con bibliotecas nativas, aumentando significativamente la escalabilidad de aplicaciones MPJ. Por otro lado, esta Tesis analiza el potencial de la computaci贸n en la nube (cloud computing) para HPC, donde el modelo de distribuci贸n de infraestructura como servicio (Infrastructure as a Service, IaaS) emerge como una alternativa viable a los sistemas HPC tradicionales. La evaluaci贸n del rendimiento de recursos cloud espec铆ficos para HPC del proveedor l铆der, Amazon EC2, ha puesto de manifiesto el impacto significativo que la virtualizaci贸n impone en la red, impidiendo mover las aplicaciones intensivas en comunicaciones a la nube. La clave reside en un soporte de virtualizaci贸n apropiado, como el acceso directo al hardware de red, junto con las directrices para la optimizaci贸n del rendimiento sugeridas en esta Tesis.[Resumo]O interese en Java para computaci贸n paralela est谩 motivado polas s煤as interesantes caracter铆sticas, tales como o seu apoio multithread, portabilidade, facilidade de aprendizaxe, alta produtividade e o aumento signi cativo no seu rendemento computacional. No entanto, as aplicaci贸ns paralelas en Java carecen xeralmente de mecanismos de comunicaci贸n e cientes, os cales adoitan usar protocolos baseados en sockets que son incapaces de obter o m谩ximo proveito das redes de baixa latencia, obstaculizando a adopci贸n de Java na computaci贸n de altas prestaci贸ns (High Performance Computing, HPC). Esta Tese de Doutoramento presenta o dese帽o, implementaci 贸n e avaliaci贸n de soluci贸ns de comunicaci贸n en Java que superan esta limitaci贸n. En consecuencia, desenvolv茅ronse m煤ltiples dispositivos de comunicaci贸n a baixo nivel para paso de mensaxes en Java (Message-Passing in Java, MPJ) que aproveitan ao m谩aximo o hardware de rede subxacente mediante operaci贸ns de acceso directo a memoria remota que proporcionan comunicaci贸ns de baixa latencia. Tam茅n se incl煤e unha biblioteca de paso de mensaxes en Java totalmente funcional, FastMPJ, na cal foron integrados os dispositivos de comunicaci贸n. A avaliaci贸n experimental amosou que as primitivas de comunicaci贸n de FastMPJ son competitivas en comparaci贸n con bibliotecas nativas, aumentando signi cativamente a escalabilidade de aplicaci贸ns MPJ. Por outra banda, esta Tese analiza o potencial da computaci贸n na nube (cloud computing) para HPC, onde o modelo de distribuci贸n de infraestrutura como servizo (Infrastructure as a Service, IaaS) xorde como unha alternativa viable aos sistemas HPC tradicionais. A ampla avaliaci贸n do rendemento de recursos cloud espec铆fi cos para HPC do proveedor l铆der, Amazon EC2, puxo de manifesto o impacto signi ficativo que a virtualizaci贸n imp贸n na rede, impedindo mover as aplicaci贸ns intensivas en comunicaci贸ns 谩 nube. A clave at贸pase no soporte de virtualizaci贸n apropiado, como o acceso directo ao hardware de rede, xunto coas directrices para a optimizaci贸n do rendemento suxeridas nesta Tese.[Abstract]The use of Java for parallel computing is becoming more promising owing to its appealing features, particularly its multithreading support, portability, easy-tolearn properties, high programming productivity and the noticeable improvement in its computational performance. However, parallel Java applications generally su er from inefficient communication middleware, most of which use socket-based protocols that are unable to take full advantage of high-speed networks, hindering the adoption of Java in the High Performance Computing (HPC) area. This PhD Thesis presents the design, development and evaluation of scalable Java communication solutions that overcome these constraints. Hence, we have implemented several lowlevel message-passing devices that fully exploit the underlying network hardware while taking advantage of Remote Direct Memory Access (RDMA) operations to provide low-latency communications. Moreover, we have developed a productionquality Java message-passing middleware, FastMPJ, in which the devices have been integrated seamlessly, thus allowing the productive development of Message-Passing in Java (MPJ) applications. The performance evaluation has shown that FastMPJ communication primitives are competitive with native message-passing libraries, improving signi cantly the scalability of MPJ applications. Furthermore, this Thesis has analyzed the potential of cloud computing towards spreading the outreach of HPC, where Infrastructure as a Service (IaaS) o erings have emerged as a feasible alternative to traditional HPC systems. Several cloud resources from the leading IaaS provider, Amazon EC2, which speci cally target HPC workloads, have been thoroughly assessed. The experimental results have shown the signi cant impact that virtualized environments still have on network performance, which hampers porting communication-intensive codes to the cloud. The key is the availability of the proper virtualization support, such as the direct access to the network hardware, along with the guidelines for performance optimization suggested in this Thesis

    Advances in knowledge discovery and data mining Part II

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    19th Pacific-Asia Conference, PAKDD 2015, Ho Chi Minh City, Vietnam, May 19-22, 2015, Proceedings, Part II</p

    Unmanned Aerial Vehicle (UAV)-Enabled Wireless Communications and Networking

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    The emerging massive density of human-held and machine-type nodes implies larger traffic deviatiolns in the future than we are facing today. In the future, the network will be characterized by a high degree of flexibility, allowing it to adapt smoothly, autonomously, and efficiently to the quickly changing traffic demands both in time and space. This flexibility cannot be achieved when the network鈥檚 infrastructure remains static. To this end, the topic of UAVs (unmanned aerial vehicles) have enabled wireless communications, and networking has received increased attention. As mentioned above, the network must serve a massive density of nodes that can be either human-held (user devices) or machine-type nodes (sensors). If we wish to properly serve these nodes and optimize their data, a proper wireless connection is fundamental. This can be achieved by using UAV-enabled communication and networks. This Special Issue addresses the many existing issues that still exist to allow UAV-enabled wireless communications and networking to be properly rolled out

    Recent Advances in Indoor Localization Systems and Technologies

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    Despite the enormous technical progress seen in the past few years, the maturity of indoor localization technologies has not yet reached the level of GNSS solutions. The 23 selected papers in this book present the recent advances and new developments in indoor localization systems and technologies, propose novel or improved methods with increased performance, provide insight into various aspects of quality control, and also introduce some unorthodox positioning methods

    XXIII Congreso Argentino de Ciencias de la Computaci贸n - CACIC 2017 : Libro de actas

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    Trabajos presentados en el XXIII Congreso Argentino de Ciencias de la Computaci贸n (CACIC), celebrado en la ciudad de La Plata los d铆as 9 al 13 de octubre de 2017, organizado por la Red de Universidades con Carreras en Inform谩tica (RedUNCI) y la Facultad de Inform谩tica de la Universidad Nacional de La Plata (UNLP).Red de Universidades con Carreras en Inform谩tica (RedUNCI
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