This paper investigates the problem of locating a continuous chemical source using the concentration measurements provided by a wireless sensor network (WSN). Such a problem exists in various applications: eliminating...
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This paper investigates the problem of locating a continuous chemical source using the concentration measurements provided by a wireless sensor network (WSN). Such a problem exists in various applications: eliminating explosives or drugs, detecting the leakage of noxious chemicals, etc. The limited power and bandwidth of WSNs have motivated collaborative in-network processing which is the focus of this paper. We propose a novel distributed least-squares estimation (DLSE) method to solve the chemical source localization (CSL) problem using a WSN. The DLSE method is realized by iteratively conducting convex combination of the locally estimated chemical source locations in a distributed manner. Performance assessments of our method are conducted using both simulations and real experiments. In the experiments, we propose a fitting method to identify both the release rate and the eddy diffusivity. The results show that the proposed DLSE method can overcome the negative interference of local minima and saddle points of the objective function, which would hinder the convergence of local search methods, especially in the case of locating a remote chemical source.
In Wireless Multimedia Sensor networks (WMSNs), data fusion and collaborative in-network processing operations often require effective multimedia synchronization control. Extensive researches have been done in the tra...
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ISBN:
(纸本)9780769547077
In Wireless Multimedia Sensor networks (WMSNs), data fusion and collaborative in-network processing operations often require effective multimedia synchronization control. Extensive researches have been done in the traditional networks. Most of these works assume that there exists a powerful synchronization controller in the network. However, for WMSNs, the in-networkprocessing of the multimedia content is usually performed based on the resource-constrained sensors. Traditional synchronization control algorithms fail to run on the low-end hardware platform. In this paper, we propose an adaptive synchronization control scheme with multi-level buffer to address this problem. Main contributions of this paper are as follows. (i) To overcome the resource constraint of WMSNs, we perform the synchronization control in a distributed way by combining the sensors in the stream transmission path. (ii) By evaluating the current network state, we adjust the level number of the buffer adaptively to balance the delay and delay jitter. (iii) Through analyzing the buffer state of each level, we propose an efficient packet scheduling scheme to reduce the delay jitter actively. (iv) We implement the proposed scheme and verify its effectiveness in our practical WMSNs platform. The experiment results show that the proposed scheme can maintain the streams synchronization effectively with the low-end sensors.
Randomized gossip algorithms are attractive for collaborative in-network processing and aggregation because they are fully asynchronous, they require no overhead to establish and form routes, and they do not create an...
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ISBN:
(纸本)9781457705137
Randomized gossip algorithms are attractive for collaborative in-network processing and aggregation because they are fully asynchronous, they require no overhead to establish and form routes, and they do not create any bottleneck or single point of failure. Previous studies have focused on analyzing the worst-case number of transmissions required to reach a specified level of accuracy. In a practical implementation, rather than always running for the worst-case number of transmissions, one would like to fix a final level of accuracy and have the algorithm run only until this level of accuracy is achieved, adapting to the initial condition and network topology. This paper describes and analyzes a local silencing rule: when a node's value has not changed significantly for enough consecutive gossip rounds, it no longer initiates new gossip transactions, thereby conserving transmissions. We provide theoretical guarantees on the final accuracy of the estimates, and we study the latency and message complexity of this approach through simulation.
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