2,566 research outputs found

    A Survey of Multi-Source Energy Harvesting Systems

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    Energy harvesting allows low-power embedded devices to be powered from naturally-ocurring or unwanted environmental energy (e.g. light, vibration, or temperature difference). While a number of systems incorporating energy harvesters are now available commercially, they are specific to certain types of energy source. Energy availability can be a temporal as well as spatial effect. To address this issue, ‘hybrid’ energy harvesting systems combine multiple harvesters on the same platform, but the design of these systems is not straightforward. This paper surveys their design, including trade-offs affecting their efficiency, applicability, and ease of deployment. This survey, and the taxonomy of multi-source energy harvesting systems that it presents, will be of benefit to designers of future systems. Furthermore, we identify and comment upon the current and future research directions in this field

    Overlay networks for smart grids

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    Dynamic and heterogeneous wireless sensor network for virtual instrumentation services

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    En el presente Trabajo Fin de Master se ha llevado a cabo el desarrollo de un sistema orientado a la adquisición de información sensorial, a través del uso de redes de sensores inalámbricas (WSN, del inglés Wireless Sensor Networks), de un sistema dinámico cuyo comportamiento se desea caracterizar. Para la gestión de la información de los sensores heterogéneos presentes en la red se han aplicado los conceptos de SOA (Service Oriented Architecture) a dicha red inalámbrica, de manera que cada uno de los sensores presentes en la red se trata como un servicio de medida. La arquitectura propuesta incorpora un mecanismo de "Plug & Play" para la reconfiguración dinámica de la red así como un proceso de composición de servicios que permite la creación de los denominados instrumentos virtuales a través de la asociación de diferentes sensores. Estos instrumentos virtuales agrupan las capacidades de varios sensores heterogeneos de forma que pueden ofrecer al usuario final información de alto nivel complementada con indicios de calidad de dicha información. Para la obtención de este sistema, las tareas que se han llevado a cabo en este trabajo han sido: se han realizado estudios previos de la utilizacion actual de las redes de sensores inalámbricas y de las arquitecturas SOA aplicadas a WSN. Se ha diseñado la arquitectura de la WSN más adecuada para esta sistema así como el mecanismo "Plug & Play" necesario para el descubrimiento de dispositivos y servicios. Se han estudiado y evaluado los criterios más adecuados para la agrupación de sensores para formar el instrumento virtual de forma automática y transparente. Por último, se ha evaluado la validez de la arquitectura propuesta por medio de su aplicación en un caso concreto en el campo de la logística, en particular, en la supervisión de artículos perecederos. Para ello, ha sido necesario diseñar y definir previamente los módulos de sofware necesarios para la implementación del sistema

    an open and modular hardware node for wireless sensor and body area networks

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    Health monitoring is nowadays one of the hottest markets due to the increasing interest in prevention and treatment of physical problems. In this context the development of wearable, wireless, open-source, and nonintrusive sensing solutions is still an open problem. Indeed, most of the existing commercial architectures are closed and provide little flexibility. In this paper, an open hardware architecture for designing a modular wireless sensor node for health monitoring is proposed. By separating the connection and sensing functions in two separate boards, compliant with the IEEE1451 standard, we add plug and play capabilities to analog transducers, while granting at the same time a high level of customization. As an additional contribution of the work, we developed a cosimulation tool which simplifies the physical connection with the hardware devices and provides support for complex systems. Finally, a wireless body area network for fall detection and health monitoring, based on wireless node prototypes realized according to the proposed architecture, is presented as an application scenario

    Middleware Technologies for Cloud of Things - a survey

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    The next wave of communication and applications rely on the new services provided by Internet of Things which is becoming an important aspect in human and machines future. The IoT services are a key solution for providing smart environments in homes, buildings and cities. In the era of a massive number of connected things and objects with a high grow rate, several challenges have been raised such as management, aggregation and storage for big produced data. In order to tackle some of these issues, cloud computing emerged to IoT as Cloud of Things (CoT) which provides virtually unlimited cloud services to enhance the large scale IoT platforms. There are several factors to be considered in design and implementation of a CoT platform. One of the most important and challenging problems is the heterogeneity of different objects. This problem can be addressed by deploying suitable "Middleware". Middleware sits between things and applications that make a reliable platform for communication among things with different interfaces, operating systems, and architectures. The main aim of this paper is to study the middleware technologies for CoT. Toward this end, we first present the main features and characteristics of middlewares. Next we study different architecture styles and service domains. Then we presents several middlewares that are suitable for CoT based platforms and lastly a list of current challenges and issues in design of CoT based middlewares is discussed.Comment: http://www.sciencedirect.com/science/article/pii/S2352864817301268, Digital Communications and Networks, Elsevier (2017

    Middleware Technologies for Cloud of Things - a survey

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    The next wave of communication and applications rely on the new services provided by Internet of Things which is becoming an important aspect in human and machines future. The IoT services are a key solution for providing smart environments in homes, buildings and cities. In the era of a massive number of connected things and objects with a high grow rate, several challenges have been raised such as management, aggregation and storage for big produced data. In order to tackle some of these issues, cloud computing emerged to IoT as Cloud of Things (CoT) which provides virtually unlimited cloud services to enhance the large scale IoT platforms. There are several factors to be considered in design and implementation of a CoT platform. One of the most important and challenging problems is the heterogeneity of different objects. This problem can be addressed by deploying suitable "Middleware". Middleware sits between things and applications that make a reliable platform for communication among things with different interfaces, operating systems, and architectures. The main aim of this paper is to study the middleware technologies for CoT. Toward this end, we first present the main features and characteristics of middlewares. Next we study different architecture styles and service domains. Then we presents several middlewares that are suitable for CoT based platforms and lastly a list of current challenges and issues in design of CoT based middlewares is discussed.Comment: http://www.sciencedirect.com/science/article/pii/S2352864817301268, Digital Communications and Networks, Elsevier (2017

    Towards persistent structural health monitoring through sustainable wireless sensor networks

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    This paper documents the design, implementation and characterisation of a wireless sensor node (GENESI Node v1.0), applicable to long-term structural health monitoring. Presented is a three layer abstraction of the hardware platform; consisting of a Sensor Layer, a Main Layer and a Power Layer. Extended operational lifetime is one of the primary design goals, necessitating the inclusion of supplemental energy sources, energy awareness, and the implementation of optimal components (microcontroller(s), RF transceiver, etc.) to achieve lowest-possible power consumption, whilst ensuring that the functional requirements of the intended application area are satisfied. A novel Smart Power Unit has been developed; including intelligence, ambient available energy harvesting (EH), storage, electrochemical fuel cell integration, and recharging capability, which acts as the Power Layer for the node. The functional node has been prototyped, demonstrated and characterised in a variety of operational modes. It is demonstrable via simulation that, under normal operating conditions within a structural health monitoring application, the node may operate perpetually
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