Wireless sensor networks (WSNs) require more complex sensor selection strategies than other distributed networks to perform optimal state estimation. In addition to constraints associated with distributed state estima...
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As larger sets of wireless sensor networks are being deployed, an important characteristic of the network which could enhance its capabilities is position awareness. While several approaches have been proposed for loc...
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ISBN:
(纸本)9781424421435
As larger sets of wireless sensor networks are being deployed, an important characteristic of the network which could enhance its capabilities is position awareness. While several approaches have been proposed for localization, that is, position awareness without using GPS, most techniques are either centralized or rely on anchor nodes. In this paper, a decentralized localization method is developed, based upon self-organizing maps. The algorithm is implemented for different size networks and the simulation results show the algorithm is efficient when compared to single processor or centralized localization methods;further the approach does not require anchor nodes. An error analysis shows that the proposed approach is a feasible method for computing the localization of sensor networks using a distributed architecture.
The proceedings contain 101 papers. The topics discussed include: role based access control in distributed object systems;security framework in a virtual large-scale disk system;pose estimation for evaluating standing...
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ISBN:
(纸本)9780769531731
The proceedings contain 101 papers. The topics discussed include: role based access control in distributed object systems;security framework in a virtual large-scale disk system;pose estimation for evaluating standing long jumps via dynamic Bayesian networks;delivery infrastructure for secure scalable coded multimedia;adaptive layered multimedia transmissions over wireless networks;bipartite graph based dynamic spectrum allocation for wireless mesh networks;real-time routing in wireless sensor networks;fast link assessment in wireless mesh networks by using non-constant weight code;flip error resistant stitching in sensor network localizations;on improving the precision of localization with gross error removal;game theoretic packet scheduling to combat non-cooperativeness in wireless mesh networks;a middleware services simulation platform for wireless sensor networks;data collection with multiple mobile actors in underwater sensor networks.
Recent years have seen the emergence of wireless sensor network systems that must support the real time query with the high data rate. sensor top K query plays a critical role for energy efficient of wireless sensor s...
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ISBN:
(纸本)9781424421077
Recent years have seen the emergence of wireless sensor network systems that must support the real time query with the high data rate. sensor top K query plays a critical role for energy efficient of wireless sensor system. In this paper we present the Filter based Top query monitoring system, which is an efficient and dynamic TOP query processing algorithm for distributedsensor networks. The objective of a top-k query is to find the k highest ranked answers/set to a user defined similarity function. The evaluation of such a query in a sensor network environment is allied with the transfer of data over an extremely expensive communication medium. Our propose system helps in order to minimize the number of tuples that have to be transferred towards the sink node. Furthermore, this system resolves queries in the network rather than in a centralized fashion, which minimizes even more the consumption of bandwidth and delay increasing the network life time and making the system energy efficient one.
Location information is always useful in Wireless sensor Networks (WSN). The precision of localization is crucial for some specific applications. Methods for node localization in WSN usually rely on the measurements o...
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Wireless sensor networks are increasingly being used in environmental monitoring applications. Collecting raw data from these networks can lead to excessive energy consumption. This is especially true when the applica...
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ISBN:
(数字)9783540691709
ISBN:
(纸本)9783540691693
Wireless sensor networks are increasingly being used in environmental monitoring applications. Collecting raw data from these networks can lead to excessive energy consumption. This is especially true when the application requires specialized sensors that have very high energy consumption, e.g. hydrological sensors for monitoring marine environments. We describe an adaptive sensor sampling scheme where nodes change their sampling frequencies autonomously based on the variability of the measured parameters. The sampling scheme also meets the user's sensing coverage requirements by using information provided by the underlying MAC protocol. This allows the scheme to automatically adapt to topology changes. Our results based on real and synthetic data sets, indicate a reduction in sensor sampling by up to 93%, reduction in message transmissions by up to 99% and overall energy savings of up to 87%. We also show that generally more than 90% of the collected readings fall within the user-defined error threshold.
A number of recently proposed mobile sensor network architectures rely on uncontrolled, or weakly-controlled mobility to achieve sensing coverage over time at low cost, an opportunistic sensor networking approach. How...
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ISBN:
(数字)9783540691709
ISBN:
(纸本)9783540691693
A number of recently proposed mobile sensor network architectures rely on uncontrolled, or weakly-controlled mobility to achieve sensing coverage over time at low cost, an opportunistic sensor networking approach. However, this reliance on mobility also introduces a number of challenges. In this paper, we discuss the challenges inherent in this networking paradigm, and describe two composable techniques, sensor sharing and substitution, to make the system more robust in terms of data fidelity and delay. We present a numerical analysis of these techniques, separately and in combination, based on a simple Markov model of an opportunistic sensor network.
Wireless sensor nodes can act as distributed detectors for recognizing activities online, with the final goal of assisting the users in their working environment. We propose an activity recognition architecture based ...
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ISBN:
(数字)9783540691709
ISBN:
(纸本)9783540691693
Wireless sensor nodes can act as distributed detectors for recognizing activities online, with the final goal of assisting the users in their working environment. We propose an activity recognition architecture based on fuzzy logic, through which multiple. nodes collaborate to produce a reliable recognition result from unreliable sensor data. As an extension to the regular fuzzy inference, we incorporate temporal order knowledge of the sequences of operations involved in the activities. The performance evaluation is based on experimental data from a car assembly trial. The system achieves an overall recognition performance of 0.81 recall and 0.79 precision with regular fuzzy inference, and 0.85 recall and 0.85 precision when considering temporal order knowledge. We also present early experiences with implementing the recognition system on sensor nodes. The results show that the algorithms can run online, with execution times in the order of 40ms, for the whole recognition chain, and memory overhead in the order of 1.5kB RAM.
Time synchronization is a critical component in many wireless sensor network applications. Although several synchronization protocols have recently been developed, they tend to break down when implemented on networks ...
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ISBN:
(数字)9783540691709
ISBN:
(纸本)9783540691693
Time synchronization is a critical component in many wireless sensor network applications. Although several synchronization protocols have recently been developed, they tend to break down when implemented on networks of heterogeneous devices consisting of different hardware components and operating systems, and communicate over different network media. In this paper, we present a methodology for time synchronization in heterogeneous sensor networks (HSNs). This includes synchronization between mote and PC networks, a communication pathway that is often used in sensor networks, but has received little attention with respect to time synchronization. In addition, we evaluate clock skew compensation methods including linear regression, exponential averaging, and phase-locked loops. Our HSN synchronization methodology has been implemented as a network service and tested on an experimental testbed. We show that a 6-hop heterogeneous sensor network can be synchronized with an accuracy on the order of microseconds.
Interactive wireless sensor networks (IWSNs) manifest diverse application architectures, hardware capabilities, and user interactions that challenge existing centralized [1], or VM-based [2] query system designs. To s...
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ISBN:
(数字)9783540691709
ISBN:
(纸本)9783540691693
Interactive wireless sensor networks (IWSNs) manifest diverse application architectures, hardware capabilities, and user interactions that challenge existing centralized [1], or VM-based [2] query system designs. To support in-network processing of streaming sensor data in such heterogeneous environments, we created SenQ a multi-layer embedded query system. SenQ enables user-driven and peer-to-peer in-network query issue by wearable interfaces and other resource-constrained devices. Complex virtual sensors and user-created streams can be dynamically discovered and shared, and SenQ is extensible to new sensors and processing algorithms. We evaluated SenQ's efficiency and performance in a testbed for assisted-living, and show that on-demand buffering, query caching, efficient restart and other optimizations reduce network overhead and minimize data latency.
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