Current Issue : July - September Volume : 2016 Issue Number : 3 Articles : 4 Articles
The processing capacity and power of nodes in a Wireless Sensor Network (WSN) are limited. And most image compression\nalgorithms in WSN are subject to random image content changes or have low image qualities after the images are decoded.Therefore,\nan image compression method based on multilayer Restricted Boltzmann Machine (RBM) network is proposed in this paper. The\nalternative iteration algorithm is also applied in RBM to optimize the training process. The proposed image compression method\nis compared with a region of interest (ROI) compression method in simulations. Under the same compression ratio, the qualities\nof reconstructed images are better than that of ROI. When the number of hidden units in top RBM layer is 8, the peak signal-to noise\nratio (PSNR) of the multilayer RBM network compression method is 74.2141, and it is much higher than that of ROI which\nis 60.2093. The multilayer RBM based image compression method has better compression performance and can effectively reduce\nthe energy consumption during image transmission in WSN....
An ISO/IEC/IEEE21451 smart sensor network for distributed measurement of pavement structural temperature (PST) is\nproposed in this paper. The proposed network architecture is a star network based on GPRS communication, adapting to the\nmeasurement environment of PST. The proposed network node consists of autonomous power supply system, network capable\napplication processor (NCAP), and smart transducer interface module (STIM). The design of hardware and software is based on\nISO/IEC/IEEE21451-1 and ISO/IEC/IEEE21451-2 standards. A human-computer interaction website is designed based on B/S three layer\narchitecture. Users having access rights can access the PST data using a browser connected to the internet. The proposed\nsystem has been used in the experimental research of the PST distribution of asphalt and cement pavement. The experimental\nresults demonstrate that the proposed smart sensor network can adapt to the distributed fieldwork and unattended measurement\nenvironment of PST.The validity and reliability of the system have also been verified....
Cooperative downloading in mobile ad hoc networks is an effective way to improve the efficiency of downloading files. This work\naddresses the problem while distributing content to a group of mobile terminals (MTs) that cooperate during the download process\nby form in g mobile ad hoc networks.However, the efficiency, cost, and energy consumption of cooperative downloading are sensitive\nby content distribution, which is a challenge to get the optimal in mobile ad hoc networks. This paper proposes a cost distribution\n(OCD) algorithm and a content distribution algorithm based on auction (OCDA) for mobile ad hoc networks based on relative\nlocation of nodes and local optimization theory. In order to make cooperative users take part when the downloading is beginning,\nseveral rounds of content distribution approach are designed based on users� relative location in the cooperative ad hoc network. To\nsatisfy users� personal demands, the paper also designs a local optimization mechanism based on cost and energy.The simulation\nresults show that the cost and content distribution method can achieve better performance, higher downloading efficiency, and\nlower energy consumption than the self-organized market algorithm (SOMA) and the average distribution algorithm (ADA)....
Network reliability of Wireless Sensor Networks (WSNs) is difficult to be evaluated because of its complexity, multistates, and\ndynamic characteristics. To satisfy the user�s need of reliability evaluation for network transmission we propose some evaluation\nmodels and a dynamical evaluation framework. The evaluation models are mission-oriented and based on transmission paths\n(uplink and downlink). The dynamic evaluation framework can be on-demand customized and it will be auto updated once the\ncommunication environment changes or the nodes fail. Finally, we simulated clustered and mesh WSNs with NS-2. Simulation\nresult shows that the proposed evaluation framework was effective and accurate....
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