111 research outputs found

    Análisis de desempeño de leach variando el porcentaje de cluster head

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    The LEACH protocol is a “standard” protocol used in the analysis and simulation of wireless sensor networks. This article analyzes the effect of varying parameter values in the LEACH protocol. In particular, the case of varying cluster head node assignments to , , and  of the total nodes of the network. Specifically, it shows the energy effect of this variation and the corresponding data traffic analysis, showing simulation results that illustrate the behavior resulting from this variation by using an approach of time-division multiplexing on the clusters.El protocolo LEACH es un protocolo “patrón” utilizado en análisis y simulación de redes de sensores inalámbricos. En este artículo, se analiza el efecto de variar los valores de los parámetros utilizados en el protocolo LEACH que, para el caso particular, se presenta la variación de asignación de nodos Cluster Head en porcentajes del ,  y  del total de los nodos de la red. En particular, se muestra el efecto energético de esta variación y su respectivo análisis de tráfico de datos, presentando resultados de simulación que ilustran el comportamiento de esta variación, bajo un enfoque de acceso múltiple por división de tiempo sobre los cluster encontrados por LEACH

    Internet of Things From Hype to Reality

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    The Internet of Things (IoT) has gained significant mindshare, let alone attention, in academia and the industry especially over the past few years. The reasons behind this interest are the potential capabilities that IoT promises to offer. On the personal level, it paints a picture of a future world where all the things in our ambient environment are connected to the Internet and seamlessly communicate with each other to operate intelligently. The ultimate goal is to enable objects around us to efficiently sense our surroundings, inexpensively communicate, and ultimately create a better environment for us: one where everyday objects act based on what we need and like without explicit instructions

    Research on Efficiency and Security for Emerging Distributed Applications

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    Distributed computing has never stopped its advancement since the early years of computer systems. In recent years, edge computing has emerged as an extension of cloud computing. The main idea of edge computing is to provide hardware resources in proximity to the end devices, thereby offering low network latency and high network bandwidth. However, as an emerging distributed computing paradigm, edge computing currently lacks effective system support. To this end, this dissertation studies the ways of building system support for edge computing. We first study how to support the existing, non-edge-computing applications in edge computing environments. This research leads to the design of a platform called SMOC that supports executing mobile applications on edge servers. We consider mobile applications in this project because there are a great number of mobile applications in the market and we believe that mobile-edge computing will become an important edge computing paradigm in the future. SMOC supports executing ARM-based mobile applications on x86 edge servers by establishing a running environment identical to that of the mobile device at the edge. It also exploits hardware virtualization on the mobile device to protect user input. Next, we investigate how to facilitate the development of edge applications with system support. This study leads to the design of an edge computing framework called EdgeEngine, which consists of a middleware running on top of the edge computing infrastructure and a powerful, concise programming interface. Developers can implement edge applications with minimal programming effort through the programming interface, and the middleware automatically fulfills the routine tasks, such as data dispatching, task scheduling, lock management, etc., in a highly efficient way. Finally, we envision that consensus will be an important building block for many edge applications, because we consider the consensus problem to be the most important fundamental problem in distributed computing while edge computing is an emerging distributed computing paradigm. Therefore, we investigate how to support the edge applications that rely on consensus, helping them achieve good performance. This study leads to the design of a novel, Paxos-based consensus protocol called Nomad, which rapidly orders the messages received by the edge. Nomad can quickly adapt to the workload changes across the edge computing system, and it incorporates a backend cloud to resolve the conflicts in a timely manner. By doing so, Nomad reduces the user-perceived latency as much as possible, outperforming the existing consensus protocols

    A METHODOLOGY FOR AUTONOMOUS ROOF BOLT INSTALLATION USING INDUSTRIAL ROBOTICS

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    The mining sector is currently in the stage of adopting more automation, and with it, robotics. Autonomous bolting in underground environments remains a hot topic for the mining industry. Roof bolter operators are exposed to hazardous conditions due to their proximity to the unsupported roof, loose bolts, and heavy spinning mass. Prolonged exposure to the risk inevitably leads to accidents and injuries. The current thesis presents the development of a robotic assembly capable of carrying out the entire sequence of roof bolting operations in full and partial autonomous sensor-driven rock bolting operations to achieve a high-impact health and safety intervention for equipment operators. The automation of a complete cycle of drill steel positioning, drilling, bolt orientation and placement, resin placement, and bolt securing is discussed using an anthropomorphic robotic arm.A human-computer interface is developed to enable the interaction of the operators with the machines. Collision detection techniques will have to be implemented to minimize the impact after an unexpected collision has occurred. A robust failure-detection protocol is developed to check the vital parameters of robot operations continuously. This unique approach to automation of small materials handling is described with lessons learned. A user-centered GUI has been developed that allows for a human user to control and monitor the autonomous roof bolter. Preliminary tests have been conducted in a mock mine to evaluate the developed system\u27s performance. In addition, a number of different scenarios simulating typical missions that a roof bolter needs to undertake in an underground coal mine were tested

    Architectural model for Collaboration in The Internet of Things : a Fog Computing based approach

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    Through sensors, actuators and other Internet-connected devices, applications and services are becoming able to perceive and react on the real world. Seamlessly integrating people, and devices is no longer a futuristic idea. Converging the physical world with the human-made realm into one network is rather a present and promising approach called The Internet of Things (IoT). A closer look at the phenomenon of IoT reveals many problems. The current trends are focusing on Cloud-centric approaches to deal with the heterogeneity and the scale of this network. The blessing of the Cloud computing becomes, however, a burden on latency-sensitive applications, which require processing and storage mechanisms in their proximity to meet low-latency, location and better context-awareness requirements. In addition to mobility support and high geographical distribution requirements. Fog computing is a new concept that focuses on extending the Cloud paradigm to the edge of the Internet of Things, via providing communication, computing, and access management support. This research project foresees and is driven by the promising opportunities of the concept behind Fog computing. In this thesis, we leverage this new concept by delivering a Collaboration Architecture for the Fog computing. This architecture constitutes a referential model to better design and to implement Fog platforms. It powers the freedom of abstraction to make development and deployment at the Fog nodes easier and more efficient. Moreover, it provides a nest where IoT-connected objects can interact and collaborate. To this end, we introduce expressive mechanisms to define and abstract objects, data analytics, and services. To leverage Fog nodes with dynamic services and service-based collaboration, we propose the concept of Operation: a formal way to dynamically generate new services through mechanisms such as aggregation, composition, and transformation. Finally, we deliver a comprehensive study and a collaboration-oriented access control model for the proposed architecture. Dans les dernières années, les avantages du Cloud Computing l’ont mis au cœur des architectures proposées pour l’Internet des Objets (IoT). L’infrastructure homogène, prédictible et performante a fait du Cloud une solution adéquate pour le traitement et l’analyse des données en provenance des objets de l’IoT. Cependant, les avantages de l’utilisation du Cloud se révèlent problématiques pour les systèmes IoT sensibles au temps de latence, et qui exigent la distribution géographique, la prise en compte de l’environnement local ainsi que la mobilité des objets. Le Fog Computing est un nouveau concept visant l'extension du Cloud vers la périphérie de l’IoT. Ainsi, il envisage une couche de nœuds (Fogs) permettant de fournir aux objets connectés un support à la gestion de la communication, à la persistance des données et à la gestion d’accès. Ce projet de recherche est motivé par les opportunités prometteuses du concept du Fog computing. Il anticipe ces opportunités et vise à proposer une architecture fédératrice, jusqu’à présent inexistante, pour la collaboration dans le Fog. De ce fait, dans cette thèse, nous tirons parti de l'idée derrière ce nouveau concept afin de proposer une architecture à cette fin. Cette architecture consiste en un modèle référentiel qui promeut à la fois une grande abstraction dans la conception des applications, ainsi que la facilité et l'efficacité dans le développement et le déploiement au niveau des nœuds de la couche du Fog. En effet, pour renforcer ces nœuds avec des services dynamiques, nous proposons des moyens formels pour la génération dynamique de nouveaux services à travers des opérations d'agrégations, de compositions ou de transformations. En conséquence, les nœuds du Fog deviennent un nid où les objets connectés peuvent interagir et collaborer à travers des mécanismes expressifs de définition et d'abstraction d’objets, des analyses de données et des services

    Season of Contemporary American Plays - Head Electrician Bundle

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    The Paperwork Bundle Archive for the Lighting Department for the Entire Season of Contemporary American Play

    High Performance Optical Transmitter Ffr Next Generation Supercomputing and Data Communication

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    High speed optical interconnects consuming low power at affordable prices are always a major area of research focus. For the backbone network infrastructure, the need for more bandwidth driven by streaming video and other data intensive applications such as cloud computing has been steadily pushing the link speed to the 40Gb/s and 100Gb/s domain. However, high power consumption, low link density and high cost seriously prevent traditional optical transceiver from being the next generation of optical link technology. For short reach communications, such as interconnects in supercomputers, the issues related to the existing electrical links become a major bottleneck for the next generation of High Performance Computing (HPC). Both applications are seeking for an innovative solution of optical links to tackle those current issues. In order to target the next generation of supercomputers and data communication, we propose to develop a high performance optical transmitter by utilizing CISCO Systems®\u27s proprietary CMOS photonic technology. The research seeks to achieve the following outcomes: 1. Reduction of power consumption due to optical interconnects to less than 5pJ/bit without the need for Ring Resonators or DWDM and less than 300fJ/bit for short distance data bus applications. 2. Enable the increase in performance (computing speed) from Peta-Flop to Exa-Flops without the proportional increase in cost or power consumption that would be prohibitive to next generation system architectures by means of increasing the maximum data transmission rate over a single fiber. 3. Explore advanced modulation schemes such as PAM-16 (Pulse-Amplitude-Modulation with 16 levels) to increase the spectrum efficiency while keeping the same or less power figure. This research will focus on the improvement of both the electrical IC and optical IC for the optical transmitter. An accurate circuit model of the optical device is created to speed up the performance optimization and enable co-simulation of electrical driver. Circuit architectures are chosen to minimize the power consumption without sacrificing the speed and noise immunity. As a result, a silicon photonic based optical transmitter employing 1V supply, featuring 20Gb/s data rate is fabricated. The system consists of an electrical driver in 40nm CMOS and an optical MZI modulator with an RF length of less than 0.5mm in 0.13&mu m SOI CMOS. Two modulation schemes are successfully demonstrated: On-Off Keying (OOK) and Pulse-Amplitude-Modulation-N (PAM-N N=4, 16). Both versions demonstrate signal integrity, interface density, and scalability that fit into the next generation data communication and exa-scale computing. Modulation power at 20Gb/s data rate for OOK and PAM-16 of 4pJ/bit and 0.25pJ/bit are achieved for the first time of an MZI type optical modulator, respectively
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