Xem 1-20 trên 35 kết quả Sensor nodes
  • Wireless Sensor Networks (WSNs) can be defined as a self-configured and infrastructure-less wireless networks to monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants and to cooperatively pass their data through the network to a main location or sink where the data can be observed and analysed. A sink or base station acts likean interface between users and the network. One can retrieve required information from the network by injecting queries and gathering results from the sink.

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  • Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Reliable Event Detectors for Constrained Resources Wireless Sensor Node Hardware

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  • Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Robust Distributed Noise Reduction in Hearing Aids with External Acoustic Sensor Nodes

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  • For the past decade, there has been rapid development and advancement in the communication and sensor technologies that results in the growth of a new, attractive and challenging research area – the wireless sensor network (WSN). A WSN, which typically consists of a large number of wireless sensor nodes formed in a network fashion, is deployed in environmental fields to serve various sensing and actuating applications.

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  • A WSN is composed of a large number of sensor nodes that are communicating using a wireless medium. The sensor nodes are deployed in the environment to be monitored in ad hoc structure. In WSN, there is sink node that collects data from all sensors, and usually not all nodes hear all other nodes. WSN is considered a multi-hop network.

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  • Event detection is one of the required services in sensor network applications such as environmental monitoring and object tracking. Composite event detection faces several challenges.The first challenge is uncertainty caused by variety of factors, while the second one is heterogeneity of sensor nodes in sensing capabilities. Finally, distributed detection,which is vital to facilitate uncovering composite events in large scale sensor networks, is challenging.

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  • Mạng cảm biến không dây (Wireless Sensor Network) là sự kết hợp các khả năng cảm biến, xử lý thông tin và các thành phần lien lạc để tạo khả năng quan sát, phân tích và phản ứng lại với các sự kiện,hiên tượng xảy ra trong môi trường cụ thể nào đó.Các cảm biến được phân bố theo mô hình tập trung hay phân bố rải. Mạng lưới liên kết giữa các cảm biến (có dây hoặc vô tuyến). Điểm trung tâm tập hợp dữ liệu . Bộ phận xử lý dữ liệu ở trung tâm....

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  • Wireless sensor nodes are small, embedded computing devices that interface with sensors/ actuators and communicate using short-range wireless transmitters. Such nodes act autonomously, but cooperatively to form a logical network, in which data packets are routed hop-by-hop towards management nodes, typically called sinks or base stations. A Wireless Sensor Network (WSN) comprises of a potentially large set of nodes that may be distributed over a wide geographical area, indoor or outdoor

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  • There are several improvements for bipartite network flows [2]. However they require the network to be unbalanced in order to substantially speed up the algorithms, i.e. either |U | |V | or |U | |V |, which is not the case in our context. The complexity of finding an optimal (minimum or maximum weight) matching might be reduced if the cost label is also a metric on the node set of the underlying graph. For example if the nodes of the graph are points in the plane and the cost label is the L1 (manhattan), L2 (Euclidean) or L∞ metric...

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  • An extended range of new sensing applications and solutions have emerged in different fields such as rural and forest fire detection [1], monitoring of industrial manufacturing processes [2], transport/logistics [3], and for personal services in areas such as healthcare and Ambient Assisted Living (AAL) [4]. These new advanced applications based on a new generation of sensing and communication capabilities are a consequence of the continuous advances in sensor technologies and wireless communication protocols that allow for greater autonomy of sensor nodes.

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  • Coverage: In WSN, each sensor node is given a glimpse of the environment. This follows are limited in range and accuracy (Figure 1), it can only include a limited physical area of environment. Therefore, coverage is also an important design parameter in WSNs. Each node receives a local view of its environment, limited by the scope and accuracy of it. the coverage of a large area composed by the union of a number of smaller insurance. Connectivity: Most of the high density of WSNs sensor, thus preventing the isolation of the nodes.

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  • Wireless Sensor Networks came into prominence around the start of this millennium motivated by the omnipresent scenario of small-sized sensors with limited power deployed in large numbers over an area to monitor different phenomenon. The sole motivation of a large portion of research efforts has been to maximize the lifetime of the network, where network lifetime is typically measured from the instant of deployment to the point when one of the nodes has expended its limited power source and becomes in-operational – commonly referred as first node failure....

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  • Query processing takes place on a database front-end while signal-processing functions are executed on the sensor nodes involved in the query. The query execution engine on the database front-end includes a mechanism for interacting with remote sensors. On each sensor a lightweight query execution engine is responsible for executing signal processing functions and sending data back to the front-end. In COUGAR, we assume that there...

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  • Existing sensor network architectures are based on the as- sumption that data will be polled. Therefore, they are not adequate for long-term battery-powered use in applications that must sense or react to events that occur at unpre- dictable times.

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  • For small join tables, REED always chooses to push them into the network if their selectivity is smaller than one. For intermediate tables, the REED query optimizer makes a decision as to whether to push the join into the network based on the estimated selectivity of the predicate (which may be learned from past performance or gathered statistics, or estimated using basic query optimization tech- niques [28]) and the average depth of sensor nodes in the network.

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  • Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Distributed and Collaborative Node Mobility Management for Dynamic Coverage Improvement in Hybrid Sensor Networks

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  • Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Collaborative Area Monitoring Using Wireless Sensor Networks with Stationary and Mobile Nodes

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  • Furniture is a ubiquitous object, i.e., it can be found everywhere at home or the office, and it can integrate and hide the sensors of a network. This work addresses the lack of an exhaustive study of the effect of furniture on signal losses. In addition an easy-to-use tool for estimating the robustness of the communication channel among the sensor nodes and gateways is proposed. Specifically, the losses in a sensor network signal due to the materials found within the communication link are evaluated.

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  • The integration of sensors in furniture brings many advantages to AmI systems, compared to other approaches that install sensors independently, for example on the wall.

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  • Consider typicalWSN applications involving the reliable de- tection and/or estimation of event features based on the collec- tive reports of several sensor nodes observing the event. Let us assume that for reliable temporal tracking, the sink must de- cide on the event features every time units. Here, represents the duration of a decision interval and is fixed by the applica- tion. At the end of each decision interval, the sink decides based on reports received from sensor nodes during that interval.

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