100,021 research outputs found

    A Unified Wireless Sensor Network Framework

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    Wireless sensor networks (WSNs) have been a significant area of research over the past decade. WSN systems are used in a wide range of applications such as surveillance, environmental monitoring, target tracking, wildlife tracking, personal health monitoring, machinery monitoring, and many others. With such wide ranging applications, there is active research in nearly every facet of the field including network topologies, communication protocols, node localization, time synchronization, and sensor data processing. This movement has largely been the result of the advances in microelectronics and low-power radio systems. These advancements have enabled the design and implementation of small, powerful, low-power, wireless sensor network systems. Like any emerging technology, a standard needs to be established to allow the advances in the field to be directly leveraged rather than requiring reinvention. This paper outlines the traditional approaches to WSN system design, and in contrast, proposes the necessary components of a unified WSN framework that would support the majority of present applications as well as providing the foundation for further advancements in the field

    Hydrologic Information Systems: Advancing Cyberinfrastructure for Environmental Observatories

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    Recently, community initiatives have emerged for the establishment of large-scale environmental observatories. Cyberinfrastructure is the backbone upon which these observatories will be built, and scientists\u27 ability to access and use the data collected within observatories to address research questions will depend on the successful implementation of cyberinfrastructure. The research described in this dissertation advances the cyberinfrastructure available for supporting environmental observatories. This has been accomplished through both development of new cyberinfrastructure components as well as through the demonstration and application of existing tools, with a specific focus on point observations data. The cyberinfrastructure that was developed and deployed to support collection, management, analysis, and publication of data generated by an environmental sensor network in the Little Bear River environmental observatory test bed is described, as is the sensor network design and deployment. Results of several analyses that demonstrate how high-frequency data enable identification of trends and analysis of physical, chemical, and biological behavior that would be impossible using traditional, low-frequency monitoring data are presented. This dissertation also illustrates how the cyberinfrastructure components demonstrated in the Little Bear River test bed have been integrated into a data publication system that is now supporting a nationwide network of 11 environmental observatory test bed sites, as well as other research sites within and outside of the United States. Enhancements to the infrastructure for research and education that are enabled by this research are impacting a diverse community, including the national community of researchers involved with prospective Water and Environmental Research Systems (WATERS) Network environmental observatories as well as other observatory efforts, research watersheds, and test beds. The results of this research provide insight into and potential solutions for some of the bottlenecks associated with design and implementation of cyberinfrastructure for observatory support

    Early forest fire detection by vision-enabled wireless sensor networks

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    Wireless sensor networks constitute a powerful technology particularly suitable for environmental monitoring. With regard to wildfires, they enable low-cost fine-grained surveillance of hazardous locations like wildland-urban interfaces. This paper presents work developed during the last 4 years targeting a vision-enabled wireless sensor network node for the reliable, early on-site detection of forest fires. The tasks carried out ranged from devising a robust vision algorithm for smoke detection to the design and physical implementation of a power-efficient smart imager tailored to the characteristics of such an algorithm. By integrating this smart imager with a commercial wireless platform, we endowed the resulting system with vision capabilities and radio communication. Numerous tests were arranged in different natural scenarios in order to progressively tune all the parameters involved in the autonomous operation of this prototype node. The last test carried out, involving the prescribed burning of a 95 x 20-m shrub plot, confirmed the high degree of reliability of our approach in terms of both successful early detection and a very low false-alarm rate. Journal compilationMinisterio de Ciencia e Innovación TEC2009-11812, IPT-2011-1625-430000Office of Naval Research (USA) N000141110312Centro para el Desarrollo Tecnológico e Industrial IPC-2011100

    From the Group of Twenty to the Group of Two: The Need for Harmonizing Derivatives Regulation Between the United States and the European Union

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    Wireless Sensor Networks are often deployed in great numbers spanning large, sometimes hard to reach and hostile, areas with the aim of monitoring environmental conditions through the use of different sensors. Due to decreasing costs of ownership (e.g. non-proprietary protocols), recent advances in processor, radio, and memory technologies and the engineering of increasingly smaller sensing devices, the availability and area of application for wireless sensor networks have steadily been increasing. Sigma Technology Development Stockholm AB raised the question as to whether a wireless sensor network, running an open-source operating system and communicating over IPv6, could be used in the field of smart autonomous irrigation? The company also required a proof-of-concept system for demonstration purposes and to identify if the design choices made were suitable for an actual implementation. There are numerous of design decisions that have to be made when constructing an irrigation system: the back-end set-up, which irrigation algorithms to use, what hardware to choose and how to communicate? This thesis therefore focuses on the overall system design of a wireless sensor network in the field of irrigation and highlights the trade-offs being made and their pros and cons. Two improvements related to the existing technology and the proof-of-concept system are presented in this thesis. Firstly, the recommendation to use clustered self-healing routing despite claimed power consumption issues. Secondly, a new technique to minimize power consumption, by dynamically changing the sleep interval on the sensor nodes with the help of weather data. Furthermore, the proof-of-concept system is constructed and analysed to assess whether the system design choices made are valid for a real-life deployment.Trådlösa sensor nätverk används för att övervaka lokala miljöförändringar med hjälp av olika sorters sensorer. På grund av nedåtgående driftkostnader (ökad tillgänglighet av open-source mjukvara) och framsteg inom processor-, radio-, och datorminnesteknolgi har både tillgängligheten och användningsområdena för trådlösa sensornätverk stadigt ökat. Sigma Technology Development AB ställde frågan huruvida ett trådlöst sensornätverk, som använder sig av ett open-source operativsystem och kommunicerar över IPv6, kunde användas inom smart konstbevattning? Företaget ville även att ett proof-ofconcept system utvecklades för demonstration samt för att kunna avgöra om de designval som gjorts är lämpliga att använda i en verklig implementation. Det finns en mängd designval som måste göras när man konstruerar ett bevattningsystem: back-end lösningen, vilka bevattningsalogritmer som ska användas, vilken hårdvara som ska användas samt hur kommunikationen mellan noderna ska upprättas? Det här examensarbetet fokuserar därför på den övergripande systemdesigen av ett trådlöst sensornätverk inom konstbevattning, utvärderar och avgör vilka kompromisser som måste göras samt för- och nackdelarna med dessa val. Examensarbetet presenterar vidare två förbättringar på det utvecklade konceptsystemet som inte heller finns på marknanden. Först rekommenderas användandet av robusta självläkande routing protokoll trots påstådda energiförbrukningsproblem. Sedan föreslås även en teknik som minimerar energiåtgången genom att dynamiskt ändra hur länge sensornoden befinner sig i ’sleep mode’, detta med hjälp av insamlad väderdata. Slutligen så konstrueras och analyseras proof-of-concept systemet för att utvärdera om dessa designval är lämpliga för en implementering i det verkliga livet

    Development of miniaturized wireless sensor nodes suitable for building energy management and modelling

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    Buildings consume 40% of Ireland's total annual energy translating to 3.5 billion (2004). The EPBD directive (effective January 2003) places an onus on all member states to rate the energy performance of all buildings in excess of 50m2. Energy and environmental performance management systems for residential buildings do not exist and consist of an ad-hoc integration of wired building management systems and Monitoring & Targeting systems for non-residential buildings. These systems are unsophisticated and do not easily lend themselves to cost effective retrofit or integration with other enterprise management systems. It is commonly agreed that a 15-40% reduction of building energy consumption is achievable by efficiently operating buildings when compared with typical practice. Existing research has identified that the level of information available to Building Managers with existing Building Management Systems and Environmental Monitoring Systems (BMS/EMS) is insufficient to perform the required performance based building assessment. The cost of installing additional sensors and meters is extremely high, primarily due to the estimated cost of wiring and the needed labour. From this perspective wireless sensor technology provides the capability to provide reliable sensor data at the required temporal and spatial granularity associated with building energy management. In this paper, a wireless sensor network mote hardware design and implementation is presented for a building energy management application. Appropriate sensors were selected and interfaced with the developed system based on user requirements to meet both the building monitoring and metering requirements. Beside the sensing capability, actuation and interfacing to external meters/sensors are provided to perform different management control and data recording tasks associated with minimisation of energy consumption in the built environment and the development of appropriate Building information models(BIM)to enable the design and development of energy efficient spaces

    Integrated sensor and management system for urban waste water networks and prevention of critical situations

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    [EN] This work describes the design and implementation of improvements to the monitoring system of an urban waste water network, resulting in more efficient management of the system. To achieve this objective, the latest communications technology has been incorporated into heterogeneous networks and sensor systems. This technology includes mobile systems, which take measurements and transmit images in real time, an intelligent platform for processing and management of variables, and the implementation of wireless sensor networks (WSNs) designed with specific protocols and tools that allow the rapid deployment of the network and allow measurements to be taken in emergency situations. The sensors in this type of installation are extremely important for the management of the system as they allow us to collect information and make decisions with sufficient time to deal effectively with critical situations such as flooding or overloading of the waste water system, or environmental problems such as dumping of possible pollutants, as well as to make the best use of the water cycle. The solution presented here automates large portions of the processes, minimizing the possibility of human error, and increasing the frequency and accuracy of the measurements taken, ensuring a robust communication system covering all the elements involved to provide ubiquity of information, and finally gives an application layer to manage the system and receive alerts. © 2011 Elsevier Ltd.This work was supported by the MCyT (Spanish Ministry of Science and Technology) under the projects PET2007-0316 and TIN2010-21378-C02-02, which are partially funded by ERDF (European Regional Development Fund).Sempere Paya, VM.; Santonja Climent, S. (2012). Integrated sensor and management system for urban waste water networks and prevention of critical situations. Computers, Environment and Urban Systems. 36(1):65-80. https://doi.org/10.1016/j.compenvurbsys.2011.07.001S658036

    Unmanned aerial vehicle based wireless sensor network for marine-coastal environment monitoring

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    Marine environments are delicate ecosystems which directly influence local climates, flora, fauna, and human activities. Their monitorization plays a key role in their preservation, which is most commonly done through the use of environmental sensing buoy networks. These devices transmit data by means of satellite communications or close-range base stations, which present several limitations and elevated infrastructure costs. Unmanned Aerial Vehicles (UAV) are another alternative for remote environmental monitoring which provide new types of data and ease of use. These aircraft are mainly used in video capture related applications, in its various light spectrums, and do not provide the same data as sensing buoys, nor can they be used for such extended periods of time. The aim of this research is to provide a flexible, easy to deploy and cost-effectiveWireless Sensor Network (WSN) for monitoring marine environments. This proposal uses a UAV as a mobile data collector, low-power long-range communications and sensing buoys as part of a single WSN. A complete description of the design, development, and implementation of the various parts of this system is presented, as well as its validation in a real-world scenario

    Energy efficient organization and modeling of wireless sensor networks

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    With their focus on applications requiring tight coupling with the physical world, as opposed to the personal communication focus of conventional wireless networks, wireless sensor networks pose significantly different design, implementation and deployment challenges. Wireless sensor networks can be used for environmental parameter monitoring, boundary surveillance, target detection and classification, and the facilitation of the decision making process. Multiple sensors provide better monitoring capabilities about parameters that present both spatial and temporal variances, and can deliver valuable inferences about the physical world to the end user. In this dissertation, the problem of the energy efficient organization and modeling of dynamic wireless sensor networks is investigated and analyzed. First, a connectivity distribution model that characterizes the corresponding sensor connectivity distribution for a multi-hop sensor networking system is introduced. Based on this model, the impact of node connectivity on system reliability is analyzed, and several tradeoffs among various sleeping strategies, node connectivity and power consumption, are evaluated. Motivated by the commonality encountered in the mobile sensor wireless networks, their self-organizing and random nature, and some concepts developed by the continuum theory, a model is introduced that gives a more realistic description of the various processes and their effects on a large-scale topology as the mobile wireless sensor network evolves. Furthermore, the issue of developing an energy-efficient organization and operation of a randomly deployed multi-hop sensor network, by extending the lifetime of the communication critical nodes and as a result the overall network\u27s operation, is considered and studied. Based on the data-centric characteristic of wireless sensor networks, an efficient Quality of Service (QoS)-constrained data aggregation and processing approach for distributed wireless sensor networks is investigated and analyzed. One of the key features of the proposed approach is that the task QoS requirements are taken into account to determine when and where to perform the aggregation in a distributed fashion, based on the availability of local only information. Data aggregation is performed on the fly at intermediate sensor nodes, while at the same time the end-to-end latency constraints are satisfied. An analytical model to represent the data aggregation and report delivery process in sensor networks, with specific delivery quality requirements in terms of the achievable end-to-end delay and the successful report delivery probability, is also presented. Based on this model, some insights about the impact on the achievable system performance, of the various designs parameters and the tradeoffs involved in the process of data aggregation and the proposed strategy, are gained. Furthermore, a localized adaptive data collection algorithm performed at the source nodes is developed that balances the design tradeoffs of delay, measurement accuracy and buffer overflow, for given QoS requirements. The performance of the proposed approach is analyzed and evaluated, through modeling and simulation, under different data aggregation scenarios and traffic loads. The impact of several design parameters and tradeoffs on various critical network and application related performance metrics, such as energy efficiency, network lifetime, end-to-end latency, and data loss are also evaluated and discussed
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