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Table of Content

    01 December 2012, Volume 32 Issue 12
    Advanced computing
    Metadata processing optimization in distributed file systems
    LIU Lian ZHENG Biao GONG Yi-li
    2012, 32(12):  3271-3273.  DOI: 10.3724/SP.J.1087.2012.03271
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    This paper analyzed the metadata processing in PVFS2, and took the remove operation as an example. To find out the bottlenecks in the remove operation, the time of each step was tested. And an optimization method to reduce the communication number by placing judgmental process on the server side was proposed, which is also suitable for other metadata operations. The optimization method was implemented in PVFS2. Compared with the original remove operation, this proposed method shows about 10% improvement in performance.
    Indirect spectral clustering towards large text datasets
    HOU Hai-xia YUAN Min-min LIU Chun-xia
    2012, 32(12):  3274-3277.  DOI: 10.3724/SP.J.1087.2012.03274
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    To alleviate the computational bottleneck of spectral clustering, in this paper a general ensemble algorithm, called indirect spectral clustering, was developed. The algorithm first grouped a given large dataset into many overclusters and then regarded each obtained overcluster as a basic object. And then the standard spectral clustering ran at this object level. By convention, when applying this new idea to large text datasets, the cosine distance would be the appropriate manner in measuring the similarities between overclusters. The empirical studies on 20-Newgroups dataset show that the proposed algorithm has a 14.72% higher accuracy on average than the K-Means algorithm and has a 0.88% lower accuracy than the normalizedcut spectral clustering. However, the proposed algorithm saves 16.8 times computation time compared to the normalizedcut spectral clustering. In conclusion, with the increase of data size, the computation time of the normalizedcut spectral clustering might become unacceptable; however, the proposed algorithm might efficiently give the nearoptimal solutions.
    Improved graph clustering algorithm and its application
    Li Ding XIANG Lai-sheng LIU Xi-yu SONG Chao-chao
    2012, 32(12):  3278-3282.  DOI: 10.3724/SP.J.1087.2012.03278
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    The fourth-party logistics company alliance building problem is to study how to build alliance with a method of high efficiency and low cost. An improved algorithm about graph clustering based on Particle Swarm Optimization (PSO) was proposed to solve the problem, and it contributed to reduce the connection cost between companies in the group. Discretization PSO was used to optimize the clustering result of graph clustering algorithm, and the result with disturbance strategies got enhanced. Clustering the 100 virtual companies, the cost was reduced from 39991 to 24800. The experimental result shows that, the improved graph clustering algorithm based on discretization PSO can solve the problem in a way with high efficiency and low cost.
    Cellular automata method for solving nonlinear systems of equations and its global convergence proof
    LU Qiuqin YANG Shao-min HUANG Guang-qiu
    2012, 32(12):  3283-3286.  DOI: 10.3724/SP.J.1087.2012.03283
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    To get all the accurate solutions to Nonlinear Systems of Equations (NSE), the algorithm with global convergence was constructed for solving NSE based on the characteristics of Cellular Automata (CA). In the algorithm, the theoretical search space of NSE was divided into the discrete space, the discrete space was defined as the cellular space; each point in the discrete space was a cell in the cellular space, and each cell was a trial solution of NSE; a cellular state consisted of position and increment of position. The cellular space was divided into many nonempty subsets, and states evolution of all cells from one nonempty subset to another realized the search of the cellular space on the theoretical search space. During evolution process of all cells, each cells transition probability from one position to any another position could be simply calculated; each state of cells during evolution corresponded to a state of a finite Markov chain. The stability condition of a reducible stochastic matrix was used to prove the global convergence of the algorithm. The case study shows that the algorithm is efficient.
    Max correntropy criteria-based nonlinear noise processing in time domain and unitary space
    JIANG Xiao MA Wen-tao
    2012, 32(12):  3287-3290.  DOI: 10.3724/SP.J.1087.2012.03287
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    Considering the problems for nonlinearnoise processing and taking account of that higher-order statistics of the signal and unitary space can be a good deal with non-Gaussian noise,the noise processing algorithm based on Max Correntropy Criteria (MCC) in the time domain and the unitary space was proposed. Combining the MCC and gradient descent algorithm, a nonlinearnoise filtering algorithm in the time domain was designed. At the same time, extending the algorithm to the noise processing in the unitary space, the unitary space filtering algorithm based on the MCC was put forward. The simulation study shows that the algorithm based on the MCC algorithm has significant advantages compared with the traditional Least Mean Square (LMS) based filtering algorithm, which means it can achieve more complete signal characteristics by faster convergence.
    Design of intelligent multi-Agent for virtual resource in cloud computing
    WANG Liu-yang YU Yang-xin ZHOU Huai
    2012, 32(12):  3291-3294.  DOI: 10.3724/SP.J.1087.2012.03291
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    Network management becomes more difficult for the increase of data transmission speed and network complexity, so the paper presented an intelligent multi-Agent model for virtual resource, described the process of the multi-Agent to virtual resource, and discussed the processing mechanism of different Agent. The proposed model was able to analyze social media resources in real-time by user context and system state. It automatically allocated resources suitable for users according to the virtual resource usage type and the information demand analysis of user context. The model was evaluated by dynamic scheduling method of virtual resources in cloud computing and the MovieLens system. The results show that the proposed model has better performance, can achieve the dynamic scheduling and load balancing of virtual resource, so that users can utilize efficiently virtual resource in the cloud computing.
    Energy-aware dynamic application partitioning algorithm in mobile computing
    NIU Rui-fang LIU Yong
    2012, 32(12):  3295-3298.  DOI: 10.3724/SP.J.1087.2012.03295
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    The limited battery life is a big obstacle for the further growth of mobile devices, so a new dynamic application partitioning algorithm was proposed to minimize power consumption of mobile devices by offloading its computation to a remote resource-rich server. An Object Relation Graph (ORG) for such an application was set up, and then it was transformed into a network. By using network flow theory, the optimization problem of power consumption was transformed into the optimal bipartition problem of a flow network which can be partitioned by the max-flow min-cut algorithm. The simulation results show that the proposed algorithm can greatly save more energy than the existing algorithms, and better adapt to environment changes.
    Fish swarm algorithm optimized by PSO applied in maximum power point tracking of photovoltaic power system
    DUAN Qi-chang TANG Ruo-li LONG Xia
    2012, 32(12):  3299-3302.  DOI: 10.3724/SP.J.1087.2012.03299
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    Introducing the velocity inertia, memory capacity of each individual and learning or communicating capacity of Particle Swarm Optimization (PSO) into the Artificial Fish-Swarm Algorithm (AFSA), a new algorithm called the “Fish-Swarm Algorithm optimized by PSO(PSO-FSA)” was put forward. In this new algorithm, the swimming of each fish has velocity inertia, and the PSO-FSA has totally five kinds of behavior pattern as follows: swarming, following, remembering, communicating and searching. The simulation analysis shows that PSO-FSA has more stable and higher performance in convergence speed and searching precision than PSO and AFSA. Finally, the PSO-FSA was applied to the maximum power point tracking of photovoltaic power generation system under partially shaded condition, and the experimental results show that PSO-FSA can find the maximum power point under partially shaded insolation conditions quickly and precisely.
    Superword level parallelism instruction analysis and redundancy optimization algorithm on DSP
    SUO Wei-yi ZHAO Rong-cai YAO Yuan LIU Peng
    2012, 32(12):  3303-3307.  DOI: 10.3724/SP.J.1087.2012.03303
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    Today, SIMD (Single Instruction Multiple Data) technology has been widely used in Digital Signal Processor (DSP), and most of the existing compilers realize automatic vectorization functions. However,the compiler cannot support SIMD auto-vectorization with the feature of DSP, because of DSP complex instruction set, the specific addressing model, the obstacle of dependence relation to vectorization non-aligned data or other reasons. In order to solve this problem, in this paper, for the automatic vectorization in the Superword Level Parallelism (SLP) based on the Open64 compiler back end, the instruction analysis and redundancy optimization algorithm were improved, so as to transform more efficient vectorized source program. The experimental results show that the proposed method can improve DSP performances and reduce power consumption efficiently.
    Artificial intelligence
    Semi-supervised multi-label classification algorithm based on local learning
    LV Jia
    2012, 32(12):  3308-3310.  DOI: 10.3724/SP.J.1087.2012.03308
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    Semi-supervised multi-label classification problem is usually decomposed into a set of single-label semi-supervised binary classification problems. However, it results in the ignorance of the inner relationship between labels. A semi-supervised multi-label classification algorithm was presented, which avoided multiple single-label semi-supervised binary classification problems but adopted the overall approach in this paper. On the basis of undirected graph, local learning regularizer for data points and Laplace regularizer for labels were introduced and regularization framework of the problem was constructed. The experimental result shows the proposed algorithm has higher precision and recall.
    k-nearest neighbors classifier over manifolds
    WEN Zhi-qiang HU Yong-xiang ZHU Wen-qiu
    2012, 32(12):  3311-3314.  DOI: 10.3724/SP.J.1087.2012.03311
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    For resolving the problem of the existing noise sample and large number of dimensions, the k-nearest neighbors classifier over manifolds was presented in this paper. Firstly the classic k-nearest neighbors was extended by Bayes theorem and local joint probability density was estimated by kernel density estimation in classifier. In addition, after building the noise sample model, an objective function was defined via improved marginal intrinsic graph and its weight matrix for searching the optimal dimension reduction mapping matrix. At last, details about k-nearest neighbors algorithm over manifolds were provided. The experimental results demonstrate that the presented method has lower classification error rate than six kinds of classic methods in most cases on twelve data sets.
    Pairwise constraint-guided sparsity preserving projections
    QI Ming-ming
    2012, 32(12):  3315-3318.  DOI: 10.3724/SP.J.1087.2012.03315
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    Concerning the deficiency of supervision information in the process of sparse reconstruction in Sparsity Preserving Projection (SPP), Pairwise Constraint-guided Sparsity Preserving Projection (PCSPP) was proposed, which introduced supervision information of must-link constraints and cannot-link constraints to guide sparse reconstruction in the process of sparsity reconstruction of training samples, making SPP fuse constraint supervise information efficiently. The experimental results in UMIST,YALE and AR face datasets show, in contrast to unsupervised sparsity preserving projections, our algorithm achieves approximately 5%~15% increase in recognition accuracy based on the nearest neighbor classifier and promotes efficiently the performance of dimensionality reduction classification.
    Improved particle swarm optimization for constrained optimization functions
    LI Ni OUYANG Ai-jia LI Ken-li
    2012, 32(12):  3319-3321.  DOI: 10.3724/SP.J.1087.2012.03319
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    To overcome the weakness of over-concentration when the population of Particle Swarm Optimization (PSO) is initialized and the search precision of basic PSO is not high, an Improved PSO (IPSO) for constrained optimization problems was proposed. A technique of Good Point Set (GPS) was introduced to distribute the initialized particles evenly and the population with diversity would not fall into the local extremum. Co-evolutionary method was utilized to maintain communication between the two populations; thereby the search accuracy of PSO was increased. The simulation results indicate that, the proposed algorithm obtains the theoretical optimal solutions on the test of five benchmark functions used in the paper and the statistical variances of four of them are 0. The proposed algorithm improves the calculation accuracy and robustness and it can be widely used in the constrained optimization problems.
    Strengthened learning and associative memory particle swarm optimization algorithm
    DUAN Qi-chang ZHANG Guang-feng HUANG Da-wei ZHOU Hua-xin
    2012, 32(12):  3322-3325.  DOI: 10.3724/SP.J.1087.2012.03322
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    In order to overcome the weakness of direction and the poorness of purpose in multidimensional search and the premature convergence, this paper presented an improved particle swarm optimization algorithm. For both the best and the worst information of the cognitive part and the best and the worst information of the social part, the improved algorithm respectively assigned different learning factors, and the algorithm has a greater ability to learn. Each particle associatively memorized the best information and the worst information in its history, and then found the optimal position in accordance with the principle of chasing the best and avoiding the worst. Associative memory overcomes the weakness of direction and the poorness of purpose in multidimensional search. The principle of chasing the best and avoiding the worst keeps the diversity of population, helps to improve the convergence speed, and overcomes the premature convergence. Simulation test of the benchmark function has verified the validity of the algorithm.
    Artificial bee colony algorithm with modified search strategy
    ZHANG Yin-xue TIAN Xue-min CAO Yu-ping
    2012, 32(12):  3326-3330.  DOI: 10.3724/SP.J.1087.2012.03326
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    A modified Artificial Bee Colony (ABC) algorithm was proposed for numerical function optimization in this paper, in order to solve the problems of slow convergence and low computational precision of conventional ABC algorithm. The modified ABC algorithm can adjust the step size of the selected neighbor food source position adaptively according to the objective function. On the other hand, the searching method based on a nonlinear adjustment of search range depending on the iteration was introduced for scout bees. The modified ABC algorithm can improve the exploitation, and avoids the premature convergence effectively. The experimental results on six benchmark functions show that, the modified ABC algorithm significantly improves the optimization ability. The modified ABC algorithm can achieve the global minimum values for numerous multimodal functions with high dimension. Compared to the other approaches, the proposed method not only obtains higher quality solutions, but also has a faster convergence speed.
    Two-tier weighting aggregation ranking algorithm
    HU Xiao-sheng ZHONG Yong
    2012, 32(12):  3331-3334.  DOI: 10.3724/SP.J.1087.2012.03331
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    In ranking for document retrieval, queries often vary greatly from one another. However, most of the existing ranking methods do not consider significant differences between queries. Correctly ranking documents on the top of the result list is crucial, and one must conduct training in a way that such ranked results are accurate. A two-tier weighting aggregation ranking method was proposed. This method consisted of two steps, training of base rankers and query-level ranker aggregation. First, base rankers were established based on each query, assigning asymmetric weights to its relevant documents, then, query-level ranker aggregation used a supervised approach to learn query-dependent weights when these base rankers were combined. The experimental results on the benchmark data set LETRO ONHSUMED show that the ranking performance has been significantly improved.
    Algorithm for Chinese short-text classification using concept description
    YANG Tian-ping ZHU Zheng-yu
    2012, 32(12):  3335-3338.  DOI: 10.3724/SP.J.1087.2012.03335
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    In order to solve the problem that traditional classification is not very satisfactory due to fewer text features in short text, an algorithm using concept description was presented. At first, a global semantic concept word list was built. Then the test set and training set were conceptualized by the global semantic concept word list to combine the test short texts by the same description of concept in the training set, and at the same time, training long texts were combined by the training short texts in the training set. At last, the long text was classified by traditional classification algorithm. The experiments show that the proposed method could mine implicit semantic information in short text efficiently while expanding short text on semantics adequately, and improving the accuracy of short text classification.
    Matrix computing-based batch learning for Madaline network with one hidden layer
    ZHANG Yin-chuan BAI Shu-kui
    2012, 32(12):  3339-3342.  DOI: 10.3724/SP.J.1087.2012.03339
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    In this paper, a matrix computing-based mathematic model was established for the feedforward discrete Madaline network with one hidden layer. By analyzing the matrix representing samples and the matrix representing attributes of the network, and combining the hyperplane division theory in high dimensional space, a batch learning method was proposed for Madaline network with the input of lower dimensional samples. This method can effectively solve the problem of two-category classification of discrete data.
    Multi-objective optimization algorithm for flow shop scheduling with family setup times
    YANG Kai-bing LIU Xiao-bing
    2012, 32(12):  3343-3346.  DOI: 10.3724/SP.J.1087.2012.03343
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    The objective optimization was to minimize total earliness/tardiness and number of setups at machine. A jointed algorithm to solve problems based on Control Weight Evolutionary Algorithm (CWEA) and optimization algorithm was presented. Firstly, the CWEA was used to determine scheduling sequence preference. Secondly, a kind of optimization algorithm was put forward to adjust the starting time for determined scheduler. The simulation results show that the effectiveness of the proposed algorithm in solving the problem.
    Service composition optimization approach based on affection ant colony algorithm
    MA Hong-jiang ZHOU Xiang-bing
    2012, 32(12):  3347-3352.  DOI: 10.3724/SP.J.1087.2012.03347
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    In the service computing mode, affection behaviour was employed to improve the efficiency of service composition. Firstly, an affection space was built to meet behaviour demands, and cognition was defined to reason state change of affection. In the change processing, mapping was done between affection and cognition, and emotion decay and emotion update were defined to maintain the stability of affective change. Secondly, affective mechanism was put into ant colony algorithm, which formed an affection ant colony algorithm, and the algorithm was applied to Web Service Modeling Ontology (WSMO) service composition. Finally, the paper adopted a Virtual Travel Agency (VTA) example under WSMO to show this approach was effective and feasible.
    Graphics and image technology
    Multifocus image fusion algorithm based on Brenner function and new contourlet transform
    MO Jian-wen MA Ai-hong SHOU Zhao-yu CHEN Li-xia
    2012, 32(12):  3353-3356.  DOI: 10.3724/SP.J.1087.2012.03353
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    In order to eliminate the aliasing phenomena of the spectrum in each direction subband of the fusion algorithm in contourlet domain and to improve the accuracy of extracting effective coefficients, a multifocus image fusion method was proposed based on the Brenner function and the New Contourlet Transform with Sharp Frequency Localization (NCT-SFL). Firstly, the new contourlet transform was used to decompose the multifocus images which to be fused. And then the traditional arithmetic mean fusion rule was used to fuse the low-frequency coefficients and the maximum local energy based on the Brenner function to fuse the high-frequency coefficients. Finally, the inverse new contourlet transform was used to obtain fused images. Using the proposed fusion method, the experimental results demonstrate that the algorithm can effectively extract the contour information of the images which to be fused, and under the premise of obtaining a better performance in terms of subjective vision, objective evaluation criterions of mutual information and transferred edge information have improved by 99.34% and 77.95% respectively. In addition, the more levels of the new contourlet decomposition, the more obvious advantages of the algorithm will show.
    High quality median prior image reconstruction algorithm based on wavelet shrinkage and forward-and-backward diffusion
    LI Xiao-hong ZHANG Quan LIU Yi GUI Zhi-guo
    2012, 32(12):  3357-3360.  DOI: 10.3724/SP.J.1087.2012.03357
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    A median priori image reconstruction algorithm based on mixed model was put forward to solve the problems of over-smoothness and stepladder edge of reconstructed image by Maximum A Posterior (MAP). First,in the median priori distribution of MAP reconstruction method,the combination of wavelet shrinkage and forward-and-backward anisotropic diffusion filter was introduced before each of median filtering. In addition, if the background area still kept a small amount of noise, the fine filter with a nonlinear diffusion that smoothed the smaller image gradient threshold region could be chosen to join in the last of iteration,so as to optimize the image.The simulation results show that the algorithm has good performance in both lowering noise effect and preserving edges. Compared with other classical algorithms,the Signal-to-Noise Ratio (SNR) can be improved by 0.9dB to 3.8dB.
    Robust variational segmentation method of 3D object in multiple-view scenes
    LIU Guang-shuai LI Bai-lin
    2012, 32(12):  3361-3364.  DOI: 10.3724/SP.J.1087.2012.03361
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    In order to solve the problems that exist in 3D segmentation reconstruction given a series of images from calibrated cameras, a variational method based on probabilistic formulation was proposed. First, through computing most probable surface that gave rise to the images, a 3D surface consistent with these segmentations was built. Then, through fusing joint probabilities, the mean intensity and variance of the extracted object and background were reconstructed. At last, by using a level set framework, the numerical implementation of surface energy equation was carried out. The proposed method can reconstruct complex topologies and cope with noisy data. Compared to carving techniques and stereoscopic segmentation, the experimental results show the effectiveness and robustness of the method with segmentation and reconstruction of arbitrary 3D objects.
    3D reconstruction method based on turntable multiple-view registration
    LI Huai-ze SHEN Hui-liang CHENG Yue
    2012, 32(12):  3365-3368.  DOI: 10.3724/SP.J.1087.2012.03365
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    An effective registration approach was proposed for multiple-view images captured on a turntable. In combination with binocular stereo, a complete system for 3D reconstruction was proposed. The calibration target was mounted on a step-motor-controlled turntable and it was acquired under multiple views. The coordinate transformation between the turntable and the camera coordinate systems was computed by the angular point information on the calibration target. The coordinate transformation among multiple views was used for data registration at the fixed viewpoint. The experimental results show that the proposed registration method achieves high precision and can be effectively used in 3D reconstruction.
    Image quality assessment based on local invariant features
    YANG Ya-zhou YIN Xiao-qing Guang-Quan Cheng TU Dan
    2012, 32(12):  3369-3372.  DOI: 10.3724/SP.J.1087.2012.03369
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    In order to overcome the deficiency of the weighted average strategy which is adopted in the structure similarity algorithm for the perception of image quality, considering that certain regions in an image may not bear the same importance as others, an image quality assessment metric based on local invariant features was put forward. The algorithm used structural similarity to calculate the quality map of distorted image, and then extracted the local invariant features points in the distorted image. The region around features points was given more visual importance, and the quality of the image distortion could be evaluated by using integrated weighting strategy. The experimental results on the standard image library show that the computational complexity of this algorithm is relatively lower and the evaluation performance of structure similarity algorithm can be considerably increased, which achieves better consistency with the subjective assessment of human eyes.
    Adaptive stereo matching based on color similarity
    LI Hong LI Da-hai WANG Qiong-hua CHENG Ying-feng ZHANG Chong
    2012, 32(12):  3373-3376.  DOI: 10.3724/SP.J.1087.2012.03373
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    A kind of area matching method that combined weights matrix with similarity coefficient matrix was proposed in this article. The article was organized as follows: first of all, the method got the weights matrix by using color similarity and distance proximity, and the value of the matrix was corrected with an edge matrix for improving correction of the edge pixels. Then a similarity coefficient matrix was adaptively obtained according to each point pairs sum of absolute difference in matching window between left image and right image. Finally, the method was investigated by matching four stereo images (Tsukuba, Venus, Teddy, and Cones) with ground truth provided in Middlebury stereo database and the rate of overall accuracy reaches 91.82%,96.19%,76.6%,86.9%,respectively.
    Three-dimensional terrain modeling based on regional feature distance weighting
    FU Yan-qiang HAN Hui-jian
    2012, 32(12):  3377-3380.  DOI: 10.3724/SP.J.1087.2012.03377
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    To improve the rendering realistic effect of the three-dimensional terrain in virtual scene, a new three-dimensional terrain modeling approach was put forward, which was based on reginal distance weighting method. In this method, the sample data was classified by the elevation value and the mapping relationship between classified data and the number of interpolation points constructed. Then, distance weighted factor was obtained by combining the Diamond-square subdivision method to compute the interpolation point coordinate data. At last, to ensure the smoothness and continuity of interpolation points, distance weighting calculation equations was established with the judgment of the interpolation point regional features. Compared with the traditional terrain modeling method, theoretical analysis and simulation results show that this method can improve the realistic effect of the 3D terrain and reduce the terrain rendering time by 20 percent.
    New algorithm for motion blur parameters synchronous identification under noise conditions
    GE Cheng-wei CHENG Hao LIU Guo-qing
    2012, 32(12):  3381-3384.  DOI: 10.3724/SP.J.1087.2012.03381
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    Under noise conditions, the black stripes of the spectrum for the uniform linear motion blurred image become obscure or even disappear. It is difficult to estimate the motion blur parameters by means of the characteristics of the black stripes. Thus, a new algorithm was proposed for motion blur parameters synchronous identification under noise conditions, which was based on the spectrum of the motion blurred image. Firstly, the contour of the white bound area was extracted using region growing algorithm, and then the minimum bounding rectangle of the contour was calculated, the motion direction and the motion length were identified simultaneously by the length, width and tilt of the minimum bounding rectangle. The experimental results indicate that, for different signal-to-noise ratios, different motion directions and motion lengths, the algorithm can be more accurate to estimate the motion blur parameters, and has good robustness. parameters, and has good robustness.
    PDE-based Image Noise Removal Models Based on Priwitt Operator
    LIU Xi-lin WANG Ze-wen QIU Shu-fang
    2012, 32(12):  3385-3388.  DOI: 10.3724/SP.J.1087.2012.03385
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    Using the normal Priwitt operator as weights, two denoising models based on Partial Differential Equation (PDE), which integrated the Gauss curvature and mean curvature diffusion, were proposed for keeping important features effectively while removing noises. First, the normal Priwitt operator of the filtered image obtained by the Gauss filter from noise image was calculated; second, the proposed models adaptively obtain the balance between the Gauss curvature diffusion noise removal and the mean curvature diffusion noise removal, thus removing noises of image. The iterative schemes of the proposed models were presented by the difference method of PDE. Then some numerical experiments were carried out. Results of experiments show that the proposed models not only converge quickly, but also are better than the denoising model based on single curvature diffusion, and better maintain the image features.
    Snow simulation model based on landscape and topography
    PENG Mian LI Chao GAN Jian-hong
    2012, 32(12):  3389-3391.  DOI: 10.3724/SP.J.1087.2012.03389
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    The author presented a snow simulation model in the 3D meteorological disaster analysis system. It could help analysts prevent snow storm and avalanches. First, the author classified the pixels of the satellite remote sensing images by their color vectors’ distance. Each of the colors represents a landscape. Then the author derived a formula by using mechanics. This formula was used to determine whether or not the snow could be covered on different regions. These regions had same landscape but different topography. If the regions were determined covered by snow according to the formula, the snow color was used to fill the regions. After this process, the satellite remote sensing images were used as textures in the 3D meteorological disasters analysis system. The experimental results show that snow effects can be produced by the snow simulation model.
    Hand gesture recognition based on bag of features and support vector machine
    ZHANG Qiu-yu WANG Dao-dong ZHANG Mo-yi LIU Jing-man
    2012, 32(12):  3392-3396.  DOI: 10.3724/SP.J.1087.2012.03392
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    According to the influence of approximate skin color information or complex background, it is hard to get precise gesture contour by hand gesture segmentation, which will have effect on later gesture recognition rate and real-time interaction. Therefore, this paper proposed a gesture recognition method based on the BOF-SVM (Bag Of Features-Support Vector Machine). At first, local invariant features of the gesture images were extracted by the Scale Invariant Feature Transformation (SIFT) algorithm. Then the visual code book was generated by gesture local eigenvector (SIFT descriptors) through K-means clustering. And visual code set of every image got quantized by visual code book. As a result, the characterized vector of gesture images with fixed dimensional was obtained to train multi-class SVM classifier. This method only needed to frame the gesture area instead of segmenting gesture accurately. The experimental results indicate that the average recognition rate of the nine interactive hand gestures based on this method can reach 92.1%. Besides, it has good robustness and efficiency, and can adapt to the changes of environment.
    Visibility estimation on road based on lane detection and image inflection
    SONG Hong-jun CHEN Yang-zhou GAO Yuan-yuan
    2012, 32(12):  3397-3403.  DOI: 10.3724/SP.J.1087.2012.03397
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    The traditional visibility meters are expensive, their sampling is limited, and some of the existing video measurement methods need artificial markers and are of poor stability. In order to solve these problems, a new algorithm for weather recognition and traffic visibility estimation through fixed camera was proposed based on lane detection and image inflection. Different from previous research, our traffic model added homogenous fog factor in traffic scenes. The algorithm consisted of three steps. Firstly, calculate the scene activity map. With the help of the Area Search Algorithm (ASA) combined with texture features, extract area for identifying. The current weather condition is foggy if the pixels from top to bottom in the extracted area change in hyperbolic fashion. At the same time calculate inflection point of image brightness curve in the extracted area. Secondly, detect traffic lane based on the retractable window algorithm, extract the lane’s endpoint and calibrate the fixed camera. Finally, according to the visibility definition, calculate traffic scene visibility by International Meteological Organization based on monocular camera model and light propagation model in fog weather condition. Through experiments of visibility estimation for three different scenes, the experimental results show that the algorithm is consistent with human eye’s observation and the accuracy rate is up to 86% while the inspection error is within 20m.
    High dimensional transfer function design based on K-Means++ for volume visualization
    CEN Zi-yuan LI Bin TIAN Lian-fang
    2012, 32(12):  3404-3407.  DOI: 10.3724/SP.J.1087.2012.03404
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    The problem how to render the important information of the volume data qualitatively in medical visualization needs to be resolved urgently. The method of designing high dimensional transfer function interactively according to the high dimension histogram was used widely, but this method is complex and is of low quality. To solve the design problems of the characteristic high dimensional transfer function, a volume rendering method of automatic and interactive design of high dimensional transfer function based on K-Means++ clustering algorithm was presented in this paper. Firstly, feature extraction was done on the volume data, then to cluster the feature space, K-Means++ clustering algorithm was used, and the group of label transfer function was generated automatically. Finally, a convenient interactive user interface was provided to users to adjust. The GPU (Graphic Processing Unit) based volume rendering was used to perform the strong parallel computing ability for real-time rendering. The experimental results show that this method can eliminate the complexity of the design of high dimensional transfer function, and many kinds of human body organization structure characteristics can be shown in the rendering results.
    Anti-shake and coordinate interpolation techniques in machine vision electronic whiteboard system application
    ZHOU Zu-wei LIU Sen WANG Yi-wen LI Hui
    2012, 32(12):  3408-3410.  DOI: 10.3724/SP.J.1087.2012.03408
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    In the electronic whiteboard system based on machine vision, an improved mean filter was proposed to eliminate touching-point jitter. In order to enhance the working fluency without hardware restrictions,a coordinate interpolation based on curve-fitting was adopted to improve the real-time performance of the whole system and smooth the trajectory of moving touching-point. The experimental results show that: on one hand, touching-point jitter can be eliminated. On the other hand, the system can output 180 touching-point coordinates per second when the camera works at its highest speed of 60 frame per second. The real-time performance of the whole system gets effectively improved without any new hardware cost.
    Improved MPEG-2 video coding scheme based on compressed sensing
    JDUAN Ji-zhong ZHANG Li-yi LIU Yu SUN Yun-shan
    2012, 32(12):  3411-3414.  DOI: 10.3724/SP.J.1087.2012.03411
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    In order to seek for applications in video coding of Compressed Sensing (CS) and improve the coding efficiency of MPEG-2, a CS and MPEG-2 based improved scheme was proposed. The improved video coding scheme chose the method producing an image with smaller Sum of Squared Differences (SSD) as the final reconstruction method between the standard reconstruction method and the Total Variation (TV) minimization algorithm in the pixel domain, which is based on the fact that the original image has sparser gradient than the residual image. The experimental results show that the proposed scheme is efficient for all kinds of video sequences. The improvement of Peak Signal-to-Noise Ratio (PSNR) is greater than 0.5dB for the sequences with sharp edges, and 0.26dB~0.41dB for sequences with smooth areas or complex textures.
    LSB matching steganalysis based on second-order differential-based Markov feature
    ZHAO Yan-li LI Zheng-yan
    2012, 32(12):  3415-3417.  DOI: 10.3724/SP.J.1087.2012.03415
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    In this paper, the author put forward a Least Significant Bit (LSB) matching steganalytic algorithm. Through calculating the second-order differential of the image pixels on horizontal and vertical directions, the differential matrix was obtained and it was used as sensitive feature extracting source and the second-order Markov transformation matrix of the differential matrix was extracted as the features, according to the LSB matching steganography with high security. According to the experimental result shows that the algorithm proposed in the paper speedups the detection process in a large extent and enhances the performance and practicability of the steganalytic algorithm while maintaining high detection accuracy, compared with the algorithms based on first-order differential Markov transition probability matrix.
    Gait recognition based on dynamic feature
    CHE Lin-lin KONG Ying-hui
    2012, 32(12):  3418-3421.  DOI: 10.3724/SP.J.1087.2012.03418
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    Considering clothes and accouterments, gait recognition method based on dynamic feature was proposed in this paper. Firstly, a value could be got by solving the Poisson equation in the gait shape area and a threshold function was constructed for dynamic feature of gait sequence. Secondly, the angle interval mean and variance of all values of the gait silhouette images in a sector region were computed. And the dynamic feature vector was constructed by them. Finally, Support Vector Machine (SVM) was used to classify the gait sequences with clothes and accouterments. The experimental results show the effectiveness of the proposed method in the CASIA gait database.
    Information security
    Research on secure interoperation in multi-domain environment
    YE Chun-xiao GUO Dong-heng
    2012, 32(12):  3422-3425.  DOI: 10.3724/SP.J.1087.2012.03422
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    The role-based access control policy is mainly to take the role mapping to achieve inter-domain interoperability. The role mapping does not consider the extent of the same role of impact on different domains, and different level of mutual trust between one domain and the other domain. Role mapping properties of the threshold and domain properties of the threshold were proposed, to solve the different problems of the same role on different domains and inter-domain trust level, and the different domains were organized in a more fine-grained access control, thus further improving the inter-domain interoperability security issues.
    Safety analysis for UCONpreA model with delegation feature and expression for DBRM0
    YE Chun-xiao YU Yi-feng
    2012, 32(12):  3426-3429.  DOI: 10.3724/SP.J.1087.2012.03426
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    In order to resolve the problem of safety analysis for Usage Control with delegation feature, this article first formalized the delegation process for its one child model, pre-authorization model; the security of a general UCONpreA model with delegation feature was undecidable through analysis, by means of constructing a finite state machine, the security of a constrained UCONpreA model with delegation feature was proved decidable; lastly, the traditional role based delegation model was simulated successfully using the constrained model. This research enhances the expression power of UCON even further, and ensures its safety effectively.
    Access control policies composition for composite Web services
    ZHANG Hong-qi Zhi-yu REN
    2012, 32(12):  3430-3434.  DOI: 10.3724/SP.J.1087.2012.03430
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    For access control policy composition problem of composite services in Web services multi-domain environment, the attribute based Web services access control policy description framework was proposed and the services access control policies were formally expressed with atomic attribute value constraint. After analyzing the control structures in services composition description document, combing the access control policy composition operators and access control policy rule composition operation, the composite Web services access control policies composition method was designed to compose the composite service access control policies. Finally, the Web services access control policy composition process was given and the practicability of composition method was verified by a case.
    Trust prediction model based on fuzzy logic in mobile Ad Hoc networks
    2012, 32(12):  3435-3438. 
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    In order to enhance the security of Ad hoc networks, a dynamic trust prediction model is presented in this paper, This model takes the account of two factors that affect trust: the node’s historical behaviors and capacity of providing services, A time decay function is introuduced to estimate the node’sdirect trust value accurately, and the node’s current trust value is assessed by using fuzzy logic rules prediction methods.Finally,we applied this model into AODV routing protocol so as to verify the validity of the model,which is defined as FTAODV routing protocol,and compared two protocol by using NS-2 simulator. Simulation results show that FTAODV routing protocol can effectively detect malicious nodes, thereby improves packet delivery ratio, decreases average end-to-end delay and routing packet overhead.
    System call anomaly detection with least entropy length based on process traces
    WU Ying JIANG Jian-hui
    2012, 32(12):  3439-3444.  DOI: 10.3724/SP.J.1087.2012.03439
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    In system call trace of a process, there are two kinds of invariability, program behavior invariability and user behavior invariability, of which the former can be further subdivided into temporal order invariability and frequency invariability. The existing researches on system call based intrusion detection techniques focus on program behavior invariability only, ignoring user behavior invariability. Based on frequency invariability embedded in process traces, the existence and description of user behavior invariability were studied, on which the least entropy length was proposed to measure the invariability. The experiment on Sendmail datasets shows that, least entropy length excellently describes user behavior invariability and significantly improves the performance of system call anomaly detection with the help of program behavior invariability.
    New virtual desktop antivirus model
    ZHAN Xu-sheng GAO Yun-wei FENG Bai-ming JIANG Yun YANG Peng-fei
    2012, 32(12):  3445-3448.  DOI: 10.3724/SP.J.1087.2012.03445
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    The existing antivirus methods take too much system overhead, consume a lot of network bandwidth and can not detect the unknown programs in time. Therefore, this paper improved the previous work and presented a new virtual desktop antivirus model regarding virtual desktop infrastructure. It supported active antivirus and passive antivirus moves. Privileged virtual machines were used to scan viruses, manage the trust-list and transmit signatures of every virtual machine to others. Agents were used to analyze the signatures and characteristics of files, optimize the bytes to be uploaded and scanned, and scan the programs timely when being loaded. The experimental results show that model can detect viruses in real-time, in the meantime reduce system overhead and network bandwidth usage.
    Research of defense scheme against buffer overflow attack in embedded system
    Liu-Bin WANG WEI Guo-heng LI Zheng
    2012, 32(12):  3449-3452.  DOI: 10.3724/SP.J.1087.2012.03449
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    Embedded system is vulnerable to buffer overflow attack. In order to solve this problem, a block based protection scheme was proposed after analyzing the memory management of μC/OS-Ⅱ. By making a combination of all the memory blocks which belong to one task and managing it through the established block_table, the introduced scheme protected the safety through creating isolation between task memories, checking and controlling the access of memory blocks. Then, an effective analysis about this scheme was given. In addition, a buffer overflow attack experiment was operated on Nios Ⅱ with the improved uC/OS-Ⅱ, and the results show that the proposed scheme is feasible.
    Implementation of complex computing cryptography algorithm based on Bluetooth chip
    HUANB Yi-cai YU Bin
    2012, 32(12):  3453-3455.  DOI: 10.3724/SP.J.1087.2012.03453
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    Through analysis on the internal structure and the working characteristic of Bluetooth chip, a parallel cryptography algorithm instruction structure model based on Digtal Signal Processor (DSP) coprocessor and the algorithm working procedure was designed. The model was designed by considering two aspects of time overhead and storage space. And the model implemented the high computational and complex cryptography algorithm with DSP coprocessor possible during the Bluetooth communication. The experimental results show that the method can reduce the influence of complex cryptography to Bluetooth transmission.
    Multi-key agreement protocol based on signature scheme
    DENG Fei HE Jun
    2012, 32(12):  3456-3457.  DOI: 10.3724/SP.J.1087.2012.03456
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    Multi-key agreement protocol can generate multi-keys in one session, so researchers are interested in it these days. In this paper, a new multi-key agreement protocol based on the traditional signature scheme was proposed. The new scheme realizes the hiding of the information between the participants and enhanced the security of our protocol by using Hash function. This paper discussed the security and computational cost of the new scheme. The result shows that the new protocol realizes the secure key agreement with lower computational cost.
    RFID authentication protocol based on secret-sharing scheme
    YANG Chao ZHANG Hong-qi
    2012, 32(12):  3458-3461.  DOI: 10.3724/SP.J.1087.2012.03458
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    The authentication efficiency of tags is always an important factor that restricts the extensive application of Radio Frequency IDentification (RFID). But there is not a good method to solve the problem till now. On the basis of tree-based RFID protocol, this article shared the secret of each path with many portions using the secret-sharing scheme. A new secret tree was created and a secret-sharing-based protocol was proposed while still keeping the searching efficiency. After being analyzed, the protocol is proved to be secure and efficient, and it also solves the key-updating problem which has slowed the study of RFID system for a long time.
    Secure LZW coding algorithm and its application in GIF image encryption
    XIANG Tao WANG An
    2012, 32(12):  3462-3465.  DOI: 10.3724/SP.J.1087.2012.03462
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    This paper proposed a Secure LZW (SLZW) coding algorithm, where encryption was embedded into the improved LZW coding process, and SLZW can fulfill compression and encryption in a single step. In SLZW algorithm, dynamic Huffman tree was utilized to code the dictionary of LZW, and the initialization and updating of Huffman tree were controlled by a sequence of keystream generated by Coupled Map Lattcie (CML). The code words were further XORed with the keystream to generate the ciphertext. The SLZW was applied to GIF image encryption. The experimental results and their analyses indicate that the proposed SLZW algorithm not only has good security, but can also improves the compression ratio by about 10%. Therefore, SLZW can find its wide applications in practice.
    Analysis and improvement of verifiable ring signature schemes
    LI Xiao-lin LIANG Xiang-qian LIU Kui PAN Shuai
    2012, 32(12):  3466-3469.  DOI: 10.3724/SP.J.1087.2012.03466
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    By analyzing the certificateless verifiable ring signature scheme (LUO DAWEN, HE MINGXING, LI XIAO. Certificateless verifiable ring signature scheme. Computer Engineering,2009, 35(15): 135-137) and the verifiable proxy ring signature scheme (LUO DAWEN, HE MINGXING, LI XIAO.A verifiable proxy ring signature scheme.Journal of Southwest University for Nationalities:Natural Science Edition, 2009, 35(3):608-611), it was found that these convertible ring signature schemes were susceptible to non-repudiation attack, i.e., any member in the ring can impersonate others identity to sign the message and the verifier believed the signature was signed by the latter. To address the above problems, improved schemes were proposed by using the private key of the signer to have a secret value. The security analysis proves that the improved schemes overcome the security defect of the original scheme and satisfy all security requirements of verifiable ring signature.
    Linear model for blind evaluation of image scrambling degree based on difference statistic distribution
    WANG Cong-li CHEN Zhi-bin XUE Ming-xi ZHANG Chao
    2012, 32(12):  3470-3473.  DOI: 10.3724/SP.J.1087.2012.03470
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    Most of the current approaches to evaluate the degree of image scrambling depend on original images. And there are no scientific mathematical models as their theoretic basis. A linear model for difference statistic distribution of ideal scrambled image was put forward in this paper by analyzing the difference statistic distribution of scrambled image. Furthermore,three methods were presented based on this model to evaluate image scrambling degree. The first one was the absolute difference of slope, the second was the absolute difference of difference, and the third was method of overlapping area. The experimental results indicate that these methods are very sensitive to the statistical distribution of image difference, and they are independent of original image with good agreement with human vision system, so they can achieve blind evaluation for image scrambling degree objectively.
    Network and communications
    TCP performance improvement of long term evolution handover
    LI Yun ZHAO Xiao-juan ZHANG Bo
    2012, 32(12):  3474-3477.  DOI: 10.3724/SP.J.1087.2012.03474
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    A dynamic Retransmission Timeout (RTO) algorithm: DRTO (Dynamic RTO) for solving the TCP packets out-of-order caused by LTE network handover was proposed. The essence of DRTO was to use the TCP packet sequence number to distinguish the old and the new packets. Hence the multiplicative factor calculated in the past traditional RTO could be replaced by the difference of the serial number. The algorithm did not need to modify the handover mechanism, which can solve the packet out-of-order between the first part of packets (the packets transferred from source eNB to target eNB) which was transferred before handover process and the second part of the packets (the packets sent by server) which was transferred after handover process. Finally, the DRTO algorithm was compared with the traditional RTO algorithm on NS-2 simulation platform. The simulation results show the DRTO algorithm is better than the traditional RTO algorithm in terms of throughput, the number of retransmission packets and latency.
    Cognitive engine based on binary ant colony simulated annealing algorithm
    XIA Ling FENG Wen-jiang
    2012, 32(12):  3478-3481.  DOI: 10.3724/SP.J.1087.2012.03478
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    In cognitive radio system, cognitive engine can dynamically configure its working parameters according to the changes of communication environment and users’ requirement. Intelligent optimization algorithm of cognitive engine had been studied, and a Binary Ant Colony Simulated Annealing (BAC&SA) algorithm was proposed for parameters optimization of cognitive radio system. The new algorithm, which introduced the Simulated Annealing (SA) algorithm into the Binary Ant Colony Optimization (BACO) algorithm, combined the rapid optimization ability of BACO with probability jumping property of SA, and effectively avoided the defect of falling into local optimization result of BACO. The simulation results show that cognitive engine based on BAC&SA algorithm has considerable advantage over GA and BACO algorithm in the global search ability and average fitness.
    Cluster Head Extraction for Data Compression in Wireless Sensor Networks
    LIN Wei LI Bo HAN Li-hong
    2012, 32(12):  3482-3485.  DOI: 10.3724/SP.J.1087.2012.03482
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    Douglas-Peucker (DP) compression algorithm of vector data compression algorithm was introduced to wireless sensor networks, at the same time for the number of scans of the data compression process, the paper put forward an improved cluster head extraction for data compression algorithm, and the cluster head was called data cluster head. Cluster head extraction compression algorithm reduced the number of data scan in compression process by setting step, and used the optimum curve fitting method for monitoring data point to do linear optimization fitting, according to the attachment relationship of the data, and extracted the cluster head data that reflected the overall characteristics; meanwhile, the subgroups of non-cluster head data subgroups were divided. The simulation results show that, the process of cluster head extraction compression algorithm is simpler; for the large fluctuation data it has a better cluster head extraction effect; besides, it reduces the amount of network data transmission, and effectively saves the energy consumption across the network.
    Network cognitive model based on fuzzy comprehensive evaluation
    WANG Wei WANG Hui ZHANG Xiao
    2012, 32(12):  3486-3489.  DOI: 10.3724/SP.J.1087.2012.03486
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    In view of the limitation of the traditional Transmission Control Protocol (TCP) used in the heterogeneous network, a network cognitive model based on fuzzy comprehensive evaluation was proposed. This model, by building the membership functions and different dynamic weight distribution under the different network environment, distinguished the wireless error loss from congestion loss according to fuzzy comprehensive evaluation. The simulation results show: compared with the traditional TCP, under different network conditions, the model can more accurately distinguish the wireless error loss from congestion loss, and improve the TCP throughput and network performance.
    Anti-collision algorithm based on priority grouping
    ZHANG Cong-li PENG Xuan YANG Lei
    2012, 32(12):  3490-3493.  DOI: 10.3724/SP.J.1087.2012.03490
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    Concerning the problems of low recognition efficiency and high misreading rate on the occasions of many tags which move fast, an anti-collision algorithm based on packet-first then handling-second was proposed. The algorithm reduced the misreading rate by to grouping the tags according to the order of arriving, it could adaptively adjust frame length based on slot situation to improve the search efficiency, and use jumping dynamic searching algorithm to deal with conflict slots, which could reduce the number of search for readers and the transmission of system. Matlab simulation results show that the algorithm’s communication complexity is lower than other commonly used algorithms, and throughput can achieve 0.59~0.6. The larger the number of tags is the more obvious superiority of the algorithm is.
    Delay tolerant network routing resource allocation model on general k-anycast
    ZHANG Yong-hui LIN Zhang-xi LIU Jian-hua LIANG Quan
    2012, 32(12):  3494-3498.  DOI: 10.3724/SP.J.1087.2012.03494
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    Delay Tolerant Network (DTN) can modify frequent network disruption and segmentation in mobile Internet access. Its core technology includes routing resource allocation. However, the existed knowledge oracles of DTN routing algorithms are time probabilistic uncertainty in public transport means mobile network or logistics, which reduces the efficiency of resource allocation. So it was proposed that general k-anycast allocates bandwidth resources to k eligible access routers in access period, which diversify the time deviation degrees and decrease the uncertainty. And access router information matrixes decide general k-anycast router aggregation. Therefore packets can be transmitted simultaneously to multiple destinations. The probabilistic uncertain utility model was further proposed for routing resource allocation based on DTN custody transfer. Simulations show that its transmission performance and robustness are better than Multicast DTN routing algorithm.
    IEEE802.15.4 guaranteed time slot performance analysis and allocation optimization under multi-slot
    CAI Hui-juan JIANG Wen-xian
    2012, 32(12):  3499-3504.  DOI: 10.3724/SP.J.1087.2012.03499
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    Every Guaranteed Time Slot (GTS) mechanism in IEEE 802.15.4 standard can be allocated multiple slots to guarantee the real-time data transmission. For the lack of analyzing multi-slot GTS performances under contention free period, the network calculus, was used to analyze the service curves of delay bound and throughput, and the connection with energy consumption.The IEEE802.15.4 sensor node model which has proposed by Jurcik and Koubaa has been improved, and modeling and simulation were done to study how GTS parameters influenced the network performances (delay, throughput and energy consumption). The simulation results indicate that according to high or low burst data rate, there is an optimized allocation of GTS parameters to meet the real-time data transmission.
    Wireless medium access control based on dynamic p-persistent algorithm
    ZHAO Hai-jun CUI Meng-tian LI Ming-dong
    2012, 32(12):  3505-3507.  DOI: 10.3724/SP.J.1087.2012.03505
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    Concerning the medium access control shortcoming of wireless network, a sort of new algorithm was proposed in this paper. The algorithm was based on the dynamic p-persistent algorithm and its kernel idea was derived from virtual transmission or virtual thread. The aim that provided more information for the dynamic p-persistent algorithm to obtain the optimal transmission probability was to increase available efficiency of wireless bandwidth. The simulations show that the proposed algorithm increases throughput about 27%, and reduces collision rate about 28% on average.
    MAC protocol based on adaptive update in wireless senor networks
    LIU Ming-zhu XU Shi-tao CHEN Guang
    2012, 32(12):  3508-3511.  DOI: 10.3724/SP.J.1087.2012.03508
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    In order to solve the energy limitation problem on wireless sensor network nodes, this paper proposed a new adaptive update asynchronous MAC protocol — AU-MAC protocol. This protocol combined the sleep-work state switching mode, asynchronous mode with adaptive update to effectively extend the network life. AU-MAC protocol improved channel usage efficiency by making use of sender monitoring and receiver activating data transfer. And, it established a neighbor node information table and introduced adaptive updating mechanism, to reduce the free monitor. The functions of AU-MAC protocol had been estimated on NS2 network simulation platform. It shows that, AU-MAC protocol improves the energy efficiency at the basis of maintaining the same throughput and end-end transit delay.
    Node energy-aware probabilistic routing algorithm for delay/disruption tolerant network
    FU Kai XIA Jing-bo LI Ming-hui
    2012, 32(12):  3512-3516.  DOI: 10.3724/SP.J.1087.2012.03512
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    Considering the problem of limited energy in Delay/Disruption Tolerant Network (DTN), a node energy-aware probabilistic routing algorithm was proposed. Nodes in network were distinguished according to energy situation, and different message delivery mechanism and energy-efficient buffer management strategy were adopted in order to achieve the balance between delivery ratio and energy consumption. Simulations indicate that the algorithm improves delivery ratio and reduces overhead ratio on low energy consumption, and has better performance on network lifetime compared with other algorithms.
    Positioning algorithm based on Internet of things spatial meshing
    HE Jia-hong ZHANG Xiao-ming WANG Yong-heng
    2012, 32(12):  3517-3520.  DOI: 10.3724/SP.J.1087.2012.03517
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    The three-dimensional spatial target localization based on wireless communication and networking technology is a hot research topic in the field of Internet of Things.However,there are still some problems including location is not accurate enough,the calculation overhead is too high and power consumption is too large.Thus,a distributed three-dimensional localization mechanism for the environment of the Internet of Things is proposed.The algorithm use Cooperative Location-Sensing(CLS) to mesh grid and determine the target location by the estimated distance.It combines Gaussian fitting ,signal sorting mechanism and Bounding-inbox algorithm which have effectively reduced signal interference.Moveover,it use local meshing to reduce the grid voting overhead.Simulation results show that the algorithm is better than the existing three-dimensional localization algorithm in positioning accuracy and have a lower power consumption.
    Improvement on localization precision and positioning rate in Grid-Scan algorithm
    LI Mu-dong XIONG Wei LIANG Qing
    2012, 32(12):  3521-3524.  DOI: 10.3724/SP.J.1087.2012.03521
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    Concerning the poor positioning rate and localization precision of Grid-Scan algorithm, an improved Grid-Scan localization algorithm based on virtual beacon nodes was proposed. Three related works were mentioned as follows: Firstly, the unknown nodes which have neighbor beacon nodes located themselves by using the beacon nodes, and the located unknown nodes were upgraded to virtual beacon nodes. Secondly, the unknown nodes that do not have neighbor beacon nodes got their location through virtual beacon nodes. Finally, different communication radiuses were set between beacon nodes, virtual beacon nodes and unknown nodes to scan in order to accomplish the localization. The simulation results show that the improved algorithm’s positioning accuracy and positioning rate increase by 6.35% and 23.37% on average respectively.
    Computer software technology
    Event-B interpretation for space aircraft description language model
    QI Yan-xia SHEN Hui-li CHEN Zhao-hui GU Bin
    2012, 32(12):  3525-3528.  DOI: 10.3724/SP.J.1087.2012.03525
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    A requirement modeling language called SPARDL was proposed for modeling and analyzing such periodic control systems consisting of periodic behaviors together with the mode transition mechanism. The Event-B interpretation was specified for the SPARDL model. The semantics of SPARDL were presented by Event-B and a refinement framework was introduced to develop the Event-B models based on the features of the SPARDL model. Finally, a case study was analyzed to show the effectiveness of our proposed approach to modeling and validation of the SPARDL model by Event-B.
    Workflow distance metric based on tree edit distance
    JIA Nan FU Xiao-dong HUANG Yuan LIU Xiao-yan DAI Zhi-hua
    2012, 32(12):  3529-3533.  DOI: 10.3724/SP.J.1087.2012.03529
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    For various applications in today’s service-oriented enterprise computing systems, such as process-oriented service discovering or clustering, it is necessary to measure the distance between two process models. In this paper, we propose a quantitative measure to calculate the distance or similarity between different structured processes. We first introduce a structured workflow model and transform each process into a process structure tree, and then calculate the process distance and its similarity based on the tree edit distance of two structure trees. The proposed distance metric satisfies three distance measure properties, i.e., identity of indiscernible, symmetry and triangle inequality. These properties make the distance metric can be used as a quantitative tool in effective process model management activities. Experiment studies show that the method is feasible. Compared to the adjacency matrix method, the proposed method is more reasonable due to the semantic distance between different structures is considered.
    Encapsulation method of manufacturing resources based on service templates
    KONG Ling-jun XU Wen-sheng CHA Jian-zhong
    2012, 32(12):  3534-3539.  DOI: 10.3724/SP.J.1087.2012.03534
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    To standardize and accelerate the encapsulation process of manufacturing resources, a novel encapsulation method of manufacturing resources was proposed based on service templates. The concept, structure and types of service templates were given according to the characteristics of manufacturing resources. Then the service template extraction procedure which utilized the existing programs of manufacturing services was proposed, and a service template extraction language was defined. The encapsulation procedure of manufacturing resources based on service templates was proposed, and the manufacturing resources were encapsulated to service-oriented architecture-based manufacturing services. At last the application case shows that the proposed method can standardize the development procedure of manufacturing services and accelerate the encapsulation process of manufacturing resources by fully utilizing existing programs of manufacturing services, so ordinary product developers can encapsulate manufacturing resources without special knowledge of software programming. This method can provide fundamental support for the sharing of manufacturing resources in the network environment.
    EDL: new approach on supporting insert-friendly XML node labels
    QIN Zun-yue HUANG Yun CAI Guo-min LIANG Ping-yuan
    2012, 32(12):  3540-3543.  DOI: 10.3724/SP.J.1087.2012.03540
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    Labeling ordered XML documents can process XML data without accessing the data files. The present labeling schemes have achieved better results in queries, however, the labeling schemes for insertions incurs sacrifices of query performance, lower updates efficiency, and other problems. This paper proposed a new labeling scheme for insertions, EDL(Extended Dewey Labeling), which efficiently realizes the calculations in the insertions of XML documents without degrading query performance . The conducted experiments have shown that EDL is superior to the similar labeling schemes for updates.
    Typical applications
    Burst detection algorithm for data streams in three dimensional under water acoustic sensor networks
    XU Ming LIU Guang-zhong
    2012, 32(12):  3544-3547.  DOI: 10.3724/SP.J.1087.2012.03544
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    Considering the multi-sourcing and heterogeneous data streams in three dimensional underwater acoustic sensor networks (3D UWASNs), this paper gives formalized definition and modeling for describing the characters and attributes of burst and presents an evolutionary game theory based burst detection algorithm for reducing processing time and improving detection performance through optimized choosing the size of slide window. We demonstrate through simulations that our burst detection algorithm consumes less processing time than traditional algorithms in the same condition of data distribution, burst probability or maximum slide window size.
    Algorithmic solution for nurse assignment problem based on GA with perturb mutation
    Lian-Min HU HONG Xu-dong HUANG Han
    2012, 32(12):  3548-3552.  DOI: 10.3724/SP.J.1087.2012.03548
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    Focusing on nurse assignment problem, this paper firstly analyzed nurse assignment problem in aspects of patient-nurse relations, nurses’ professional titles, patients’ nursing grades. An improved stochastic programming model was built which was more suitable for hospitals in China. Then according to the solution structure of the problem, a Genetic Algorithm with Perturb Mutation (PMGA) which was added on every vectors among the solution with a probability was designed. Compared to random greedy algorithm and Bender’s decomposition based greedy algorithm in experiment, PMGA results were more effective than other methods in solving nurse assignment problem within 30 minutes and it would reduce workload more than 8.9% for each nurse in a shift. Especially, GA with perturb mutation was more efficient in solving multi-scenario, multi-trap nurse assignment problems which have solutions without field continuity.
    Rescheduling algorithm for steelmaking and continuous casting based on dynamic constraint satisfaction
    HOU Dong-Liang LI Tie-ke
    2012, 32(12):  3553-3557.  DOI: 10.3724/SP.J.1087.2012.03553
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    A rescheduling problem of steelmaking-continuous casting with tapping tardiness was studied in this paper. And a dynamic constraint satisfaction model was established to minimize the difference of the starting time, processing time and processing machine and waiting time of the heat between the adjacent equipment. According to this model, a local repair algorithm based on dynamic constraint satisfaction techniques and interrupted-cast repair rules was put forward. In this method, variable selection and value selection rules were used to assign one value to a variable. The conflict identification and elimination principles were used to identify and eliminate the conflicts in the assignment. The interrupted-cast repair heuristic rule was used to repair the interrupted-casts in a continuous casting machine. In this experiment, three groups of random data with a uniform distribution were generated. Target values were 0.15, 0.28 and 0.51. The results demonstrate that the size of the delay time has a certain influence on target value and the algorithm can satisfy the needs of real-time and stability as much as possible.
    Tax forecasting based on Adaboost algorithm and BP neural network
    LI Xiang ZHU Quan-yin
    2012, 32(12):  3558-3560.  DOI: 10.3724/SP.J.1087.2012.03558
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    In view of the lower accuracy of traditional tax forecasting models, the authors put forward a method of combining the Adaboost algorithm with BP neural network to forecast revenue. Firstly, the method performed the pretreatment for the historical tax data and initialized the distribution weights of test data; secondly, it initialized the weights and thresholds of BP neural network, and used BP neural network as a weak predictor to train the tax data repeatedly and adjust the weights; finally, it made more weak predictors of BP neural network to form new strong predictors by Adaboost algorithm and forecasted. The authors also carried out simulation experiment for the tax data of China from 1990 to 2010. The results show that this method has reduced the relative value of mean error from 0.50% to 0.18% compared to the traditional BP network, has effectively reduced the effect when single BP gets trapped in local minima, and has improved the prediction accuracy of network.
    Hot rolling products quality test system based on neural network with function of quality-track
    HUA Ji-wei LU Yao LEI Zhao-ming XU Wei-xin
    2012, 32(12):  3561-3564.  DOI: 10.3724/SP.J.1087.2012.03561
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    Concerning the problem in the conventional neural network expert system that can not provide explaining facility and reasoning process, the hot rolling products quality test system based on Radial Basis Function (RBF) neural network with function of qualitytrack can overcome the shortcoming. In the part of quality test, it provided detailed explanations and tracking process of the output of the expert system. According to the characteristics of steel industry, it used multiRBF neural network in the part of physical properties test. Firstly it used RBF neural network to forecast physical properties, and then dealt with the input parameters with the multiquadratic function. Finally it made longitudinal tracing and horizontal tracing to the result. The practical application result shows this system improves the degree of automation and the efficiency quality test in iron and steel enterprise. Compared with the previous way, it saves 60% of the time.
    Spam phone number filtering method based on SMS submission pattern
    ZHU Wu-hui WANG Mei-qing
    2012, 32(12):  3565-3568.  DOI: 10.3724/SP.J.1087.2012.03565
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    In a time flooded with massive spam messages, clearing them waste a huge amount of effort and time. The mining sent feature of spam messages is the key to solving this problem. On the basis of analyzing current text-message filtering mechanisms, an effective interaction period is proposed by combining the discrete interaction units of the message sender into a consecutive interaction unit according to the essence of median filter. Utilizing the ratio of input to output and Effective Interaction Period (EIP), a general filtering algorism of spam message is built. Experimenting on 20 millions real messages, the recall ratio of the proposed algorithm is 99.51% and the precision ratio is 49.90%. The experimental results indicate that the novel algorism greatly enhances the efficiency and velocity of detection, which can be applied to spam messages real-time intercepted technology.
2024 Vol.44 No.3

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