By researching Voronoi diagram, parallel algorithm, and divide-and-conquer method, we present a special data structure(change doubly-connected list little) for Voronoi diagram generation in parallel. In this paper we ...
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By researching Voronoi diagram, parallel algorithm, and divide-and-conquer method, we present a special data structure(change doubly-connected list little) for Voronoi diagram generation in parallel. In this paper we also present two proposal, they are one processor gradually to merge and 22-merger on the parallel machine, the experiment results show that the present algorithm runs faster than the serial program. By analyzing the various results, we should choose the most suitable number of processors according to the point set scale. At last, we can conclude that gradually merger with one processor is better proposal for Voronoi diagram parallel generation.
The population protocol model has emerged as an ele gant paradigm for describing mobile ad hoc networks, con sisting of a number of nodes that interact with each other to carry out a computation. One essential propert...
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The population protocol model has emerged as an ele gant paradigm for describing mobile ad hoc networks, con sisting of a number of nodes that interact with each other to carry out a computation. One essential property of self stabilizing population protocols is that all nodes must even tually converge to the correct output value, with respect to all possible initial configurations. It has been shown that fairness constraints play a crucial role in designing popula tion protocols. The Process Analysis Toolkit (PAT) has been developed to perform verifications under different fairness constraints efficiently. In particular, it can handle global fairness, which is required for the correctness of most of population protocols. It is an ideal candidate for automati cally verifying population protocols. In this paper, we sum marize our latest empirical evaluation of PAT on a set of self-stabilizing population protocols for ring networks. We report one previously unknown bug in a protocol for leader election identified using PAT.
In this work, we study a link-weighted and distance-constrained channel assignment problem in multi-channel mesh networks with stationary router nodes, such as community wireless networks. A good channel assignment is...
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In this work, we study a link-weighted and distance-constrained channel assignment problem in multi-channel mesh networks with stationary router nodes, such as community wireless networks. A good channel assignment is given as the one which can minimize interference of each link from its neighboring links and subsequently improve the network throughput. In response to it, we introduce an interference metric, namely, min-max i-value of an edge (MMIE), to explicitly accounts for interference among links that are at distance one. In addition, we further show that the link-weighted and distance-constrained channel assignment problem with respect to the interference metric is NP-hard in computation. This guides us to propose a new heuristic channel assignment algorithm called LD-CA algorithm. We study the performance of our algorithm by implementing it in a wireless simulation environment consisting of 25 nodes, each equipped with one 802.11 wireless card. The ns-2 simulation results show that in a multi-channel environment, the LD-CA algorithm significantly outperforms previously proposed channel assignment schemes by minimizing MMIE of all links.
In this paper, an eXtended Stepwise Dimension Reduction approach (XSDR) to evolutionary design of relatively large combinational logic circuits is proposed. In our previous work, a Stepwise Dimension Reduction approac...
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In this paper, an eXtended Stepwise Dimension Reduction approach (XSDR) to evolutionary design of relatively large combinational logic circuits is proposed. In our previous work, a Stepwise Dimension Reduction approach (SDR) is introduced. The SDR divides a circuit into several layers. The layers are evolved one after another. However, some layers are difficult to be evolved. The XSDR improves the SDR by decomposing the original truth table of a layer to two truth tables. The new truth tables after decomposing are easy to be evolved. The proposed method has been tested with multipliers and the circuits taken from the Microelectronics Center of North Carolina (MCNC) benchmark library. The experimental results demonstrate that the XSDR extensively improves the performance of the SDR in terms of the number of fitness evaluations and the computational time.
作者:
GUYuZHAOBaohuaDepartment of Computer Science
University of Science and Technology of China Anhui Province Key Laboratory of Software in Computing and Communication Hefei 230027 China
In this paper, we focus on the target tracking problem in sensor networks and propose an Powersaving target localization scheme (PSTL) based on a conjecture model that reflects the moving pattern of a target, and also...
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In this paper, we focus on the target tracking problem in sensor networks and propose an Powersaving target localization scheme (PSTL) based on a conjecture model that reflects the moving pattern of a target, and also a corresponding two-step communication protocol between Base station (BS) and sensors. BS executes a query mechanism to determine which sensors should be used for detailed information according to a limited amount of data received from sensors. This scheme reduces both energy consumption and communication bandwidth requirement, prolongs the lifetime of the wireless sensor networks. Simulation results indicate that it can achieve a high accuracy while saving a large amount of energy.
作者:
HUTianZHAOBaohuaDepartment of Computer Science
University of Science and Technology of China Anhui Province Key Laboratory of Software in Computing and Communication Hefei 230027 China
This paper focuses on the problem of constructing the minimum-energy broadcast trees in all-wireless networks. We proposed a greedy algorithm called Greedy maximum-branch replacement algorithm (GMBR) to decrease the t...
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This paper focuses on the problem of constructing the minimum-energy broadcast trees in all-wireless networks. We proposed a greedy algorithm called Greedy maximum-branch replacement algorithm (GMBR) to decrease the total power of the broadcast tree further. This algorithm can be developed to a distributed one easily. Compared with the previous algorithms, GMBR was proved to have better performance, especially when the propagation loss exponent and the network size become larger.
At present, moving vehicle detection on airborne platform has been an important technology for urban traffic surveillance. In such a situation, most commonly used methods (e.g. image subtraction) could hardly work wel...
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The task of Aircraft Landing Scheduling (ALS) is to give a landing sequence and landing times for a given set of aircrafts where many constraints must be satisfied. ALS is an NP-hard problem with large-scale and multi...
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Since infrared images reflect the temperature-field distributing of vein¿s embranchment of the face, expression recognition from them should focus on changes of thermal distribution on facial muscles and blood ve...
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Since infrared images reflect the temperature-field distributing of vein¿s embranchment of the face, expression recognition from them should focus on changes of thermal distribution on facial muscles and blood vessels, which caused by mood variety. These thermal changes can be regarded as texture features of images. Wavelet transform is a good tool to analyze multi-scale, multi- direction changes of texture. Therefore, this paper presented a facial expression recognition method from thermal images using wavelet transform. Firstly, the status quo of the researches on infrared facial expression recognitions was briefly surveyed and analyzed. Secondly, wavelet transforms were used to extract image features. Thirdly, the ¿Euclidian Distance Maximizing Method¿ we proposed was adopted to select features. Then principal component analysis was employed to reduce feature dimension and NN was used as a classifier. Finally, experiments on medium-wave thermal facial expressions database of Equinox evaluated the effectiveness of our approach.
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