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05 August 2012, Volume 38 Issue 15
    

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    Networks and Communications
  • XU Chao, LIU Li-Xiang
    Computer Engineering. 2012, 38(15): 1-4. https://doi.org/10.3969/j.issn.1000-3428.2012.15.001
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    This paper enhances the reliability of the data communication mechanism in GMPRS Logical Link Control(LLC) protocol, to address the issues of long delay and high bit error rates over GEO link. It proposes RBM-ARQ algorithm based on bitmap for reliable data communication. RBM-ARQ enhances the recovery of channel impairment by keeping the terminals updating the buffer status. Simulation results show when retransmission time and count are set properly, LLC layer throughput gets better and delay becomes smaller, and compared with GMPRS LLC layer acknowledged data transfer, RBM-ARQ algorithm achieves better performance and the better recovery of data.

  • GAO Lin, FAN Yong, CHEN Nian-Nian, LI Yu-Feng, LI Gui-Zhuo, ZHANG Jin-Feng
    Computer Engineering. 2012, 38(15): 5-8. https://doi.org/10.3969/j.issn.1000-3428.2012.15.002
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    A novel visual tracking algorithm based on sparse representation is proposed to solve the problem of occlusion. The tracked object is described using the sparse representation method, and the image Gabor-features are used to construct the object dictionary and occlusion dictionary. The optimal sparse coding coefficients are obtained via l1-norm minimization. The tracking algorithm is designed in a particle filtering framework. The occlusion is judged according to the distribution of nonzero values in sparse coding coefficients. Under occlusion, the particles’ weight is calculated based on the approximation residual of observation by sparse representation. A template reliability evaluation method is introduced to suppress the drift during the object dictionary update. Experimental results show that the proposed algorithm can handle occlusion efficiently, and be robust to pose and illumination variations.

  • HU Chong-Bin, LIN Gang, LIN Xiao-Kang
    Computer Engineering. 2012, 38(15): 9-11,15. https://doi.org/10.3969/j.issn.1000-3428.2012.15.003
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    In systems with delay constrained traffic, the Channel State Information at the Transmitter(CSIT) is obtained slot by slot. The precoder design exploiting this incomplete CSIT is studied in this paper. An Optimized(OPT) power allocation algorithm based on the quantization of received power and a suboptimal but much simpler Hybrid Power Allocation(HPA) algorithm are proposed. Numerical results verify the efficiency of the proposed designs. For example, in a system with delay constraint 4 slots, the OPT and HPA precoders improve the system performance by 6.1 dB and 5.8 dB respectively.

  • TAO Jian-Bei, ZHANG Chao
    Computer Engineering. 2012, 38(15): 12-15. https://doi.org/10.3969/j.issn.1000-3428.2012.15.004
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    Mutual information game theory is introduced in the decision-making process of the cryptographic chips designers (defense party) and the attacker, a risk quantification evaluation model based on mutual information game is built. It investigates the attack and designs tactics choice to security risks, and combining with the quantitative methods of the mutual information, gives the optimization tactics selection method of the both sides of attack and designs on Nash equilibrium conditions, gives the mutual information benefits of the both sides of attack and designs on Nash equilibrium. Through the case analysis, the validity of the strategy is proved.

  • LUO Dun, ZHANG Guo-Beng
    Computer Engineering. 2012, 38(15): 16-19. https://doi.org/10.3969/j.issn.1000-3428.2012.15.005
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    Aiming at the encryption system with lower security requirements, this paper puts forward a symmetrical key automatic changing cryptography scheme based on simple hybrid selection coding, with the combination of unilateral canonical Huffman coding and fixed-length coding. The statistical results of plaintext are used as their own encrypted key and coding basis, which makes the scheme to be easy to implement and calculate and of cost low. It is proved that when the keys are completely unknown, the cracking of the encryption system has great difficulty.

  • ZHENG Zhi-Wen-?, LIN Zhen-Fang, LI Dun, LI Lun
    Computer Engineering. 2012, 38(15): 20-22,27. https://doi.org/10.3969/j.issn.1000-3428.2012.15.006
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    A pre-transfer method based on Segment Selection Not Used Recently(SSNUR) algorithm is presented to solve low availability caused by the traditional copy technology in the virtual machine hot standby. The used memory pages are pre-transferred in the running phase of the virtual machine, in order to reduce the number of memory pages to copy in the shutdown phase, and SSNUR algorithm is proposed to select the pages need to copy in order to reduce the repetition rate of pre-transfer and stop-transfer. Experimental results show that the pre-transfer Remus compred with the original method has obvious advantages when the virtual machines have heavy load and long intervals, and downtime can be reduced up to 23.37%.

  • LENG Meng, SUN Ling-Yu, BIAN Ji-Nian, MA Yu-Chun, SHU Beng
    Computer Engineering. 2012, 38(15): 23-27. https://doi.org/10.3969/j.issn.1000-3428.2012.15.007
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    The Cellular Automata(CA) model for the problem by applying the CA theory and a min-cut partitioning algorithm based on the model for bisecting weighted hypergraph are proposed. In the model, the vertex of hypergraph can be considered as the cell, the vertices of adjacent hypergraph are denoted by the CA-neighborhoods and each cell’s state represents the partitioning which the corresponded vertex belongs to. Furthermore, the two-dimensional auxiliary array is designed for counting the vertices of each hypergraph in different partitions. The rapid method of calculating the cell’s gain and the cut’s size are proposed to avoid traversing each vertex of hypergraph. Experimental results show that the algorithm not only can find the better partitioning of weighted hypergraph than the move-based method and graph parti-tioning algorithm, but also can reduce the time complexity and the space complexity.

  • JIAO Dong-Lai, ZHANG Shu-Liang, SHU Cai-Yang
    Computer Engineering. 2012, 38(15): 28-30. https://doi.org/10.3969/j.issn.1000-3428.2012.15.008
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    According to the Geography Markup Language(GML) application requirements, this paper designs a GML data parsing method based on simple API. It defines the GML application semantics, and analyzes the GML mode with Xerces. Through recursive algorithm to determine the semantics of GML tags, it builds the parser based on the adapter pattern and event-driven, and extracts GML data of semantic block. Experimental results show that this method can realize the query, index and visualization of GML data.
  • GUO Chao-Zhong, HU Jin-Chen, CHEN Jian-Xun
    Computer Engineering. 2012, 38(15): 31-34. https://doi.org/10.3969/j.issn.1000-3428.2012.15.009
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    This paper proposes an improved general algorithm for the transcendental functions, which is appropriate for the high-performance computing. Based on various technologies, such as conversion, approximation and reconstruction, it advances the progression algorithm and iteration algorithm, designs the functions with the aid of the interval with best astringency. Additionally, the cumulative error caused by repeated operations is also reduced by minimizing the operation frequencies, so as to guarantee the function accuracies. At the same time, algorithm overheads are well reduced by constructing auxiliary tables with the look-up table algorithm. Experimental results show that the performance of the mathematic library functions based on this paper can be promoted by 50.91% compared with those of the GNU mathematic library.
  • WANG Xu, CHEN Yu-Ting
    Computer Engineering. 2012, 38(15): 35-38,42. https://doi.org/10.3969/j.issn.1000-3428.2012.15.010
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    A multi-threaded program can contain a data race when two or more threads access the same memory location under no ordering constraints and at least one access is a write operation. The existence of data races can lead to many kinds of harmful program behaviors, including determinism violations, corrupted memory, and so on. It proposes a new algorithm for static detection of data races in X10 parallel programs, which contains four steps: pairs of sources accesses computation, pairs of reachable accesses computation, pairs of clockwise accesses computation, and escape analysis of accessing pairs computation. The essential idea of this approach is to construct the call graph of the program on the basis of the WALA, and then to compute pairs of sources accesses for detecting potential data races. Experimental results show that the algorithm performs well and can find and report potential data races in a cost-effective manner.
  • YUAN Kai-Yin, GUO Rui, LIU Xiang-Sheng, TUN Jin-Zhao
    Computer Engineering. 2012, 38(15): 39-42. https://doi.org/10.3969/j.issn.1000-3428.2012.15.011
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    This paper establishes the Promela model of the Web Ontology Language for Service(OWL-S) process model for Role Goal Process Service(RGPS) process level meta-model, uses Linear Temporal Logic(LTL) to describe the properties of models, and uses the partial order reduction and on-the-fly optimization techniques of model checking tools Spin to verify the properties. It designs and implements RGPS process level meta-model correctness verification platform. The effectiveness of this verification framework is demonstrated by a case study in urban transportation system.
  • LIU Dong, WEI Yong-Qing, XUE Wen-Juan
    Computer Engineering. 2012, 38(15): 43-45. https://doi.org/10.3969/j.issn.1000-3428.2012.15.012
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    Traditional data mining algorithm has computing power shortage in dealing with mass data set. Aiming at the problem, a distributed sequential pattern mining algorithm based on Map Reduce programming model named MR-PrefixSpan is proposed. Mining tasks are decomposed to many, the Map function is used to mine each Prefix-projected sequential pattern, and the projected databases are constructed parallelly. It simplifies the search space and acquires a higher mining efficiency. Then the intermediate values are passed to a Reduce function which merges together all these values to produce a possibly smaller set of values. Experimental results on Hadoop cluster show that MR-PrefixSpan can reduce the time of scanning data base, has higher parallel speed up ratio and better expansibility.
  • GAO Jun, HAO Zhong-Xiao
    Computer Engineering. 2012, 38(15): 46-49. https://doi.org/10.3969/j.issn.1000-3428.2012.15.013
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    This paper proposes the concept of Line Point Nearest Neighbor(LPNN) query in spatial database on the base of line segment Nearest Neighbor(NN) query and designs the LPNN query algorithms. The algorithm uses filter-refine frame. It filters query data sets by means of the direct influence area of line and choosing rules to reduce search area. It uses priority queue in refinement process for avoiding overlap compute of same point and gets the line point NN query results. Experimental results show that the algorithm has a better query performance.
  • WANG Jian, LI Zhi-Bin, LIN Hong-Fei
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    This paper concerns with the issue of how to enhance Web retrieval with social annotations. It proposes a weighted social SimRank algorithm to get the similarity information of pages and annotations from social tagging system. The two types of similarity information are used to calculate quality of the pages and the relevance between pages and queries, respectively. And the pages are reordered according to the pages’ quality and relevance information. Experiments are carried out on a real-world annotation data set which is sampled from del.icio.us. Experimental results show the significant improvements over traditional methods and the effectiveness of the proposed algorithm.
  • DIAO Shuo, CHEN Zhong-Yo, XIAO Chun-Shui
    Computer Engineering. 2012, 38(15): 53-55,58. https://doi.org/10.3969/j.issn.1000-3428.2012.15.015
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    Aiming at the problem that individual component can not completely meet users requirements in Component-based Software Development(CBSD), a component combination method is presented. Based on category theory, this paper presents a method to formal description components. Using the graphical characteristics supported in category theory, it models the components and interactions between components behavior. A combination method of component behavior based on graphic pushout is given and presented. Example application result shows that the method of components formal description is more accurate, more effective and efficient components combination.
  • CAI Rang-Zhuo-Ma, CAI Zhi-Jie
    Computer Engineering. 2012, 38(15): 56-58. https://doi.org/10.3969/j.issn.1000-3428.2012.15.016
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    Based on the research foundlings of Chinese corpus’ extraction, this paper presents the Tibetan preprocessing method and the high-frequency words extraction algorithm, which consists of the tables of noise words, tighten-word, preprocessing method and high-frequency words extraction algorithm. Experimental results show that this algorithm achieves a precision of 86.22%, a recall of 89.79%, and an F-measure of 87.94%.
  • LI Kai-Li, WANG Li-Hong
    Computer Engineering. 2012, 38(15): 59-61,65. https://doi.org/10.3969/j.issn.1000-3428.2012.15.017
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    Some concepts such as all attribute itemset, absolute association rule, key antecedent of association rule are proposed to solve information annihilating problem caused by the combination explosive of itemset in associated rules mining without support. This paper proves an important theory, the association rule with the antecedent of key antecedent’s super set must be absolute association rule, and it is upward closure. Based on this principle, a targeting association rule mining algorithm is designed to eliminate redundancy association rule significantly. Through an instance, the feasibility and effectiveness of the algorithm are verified.
  • HUI Ting-Ting, NIE De-Guo, WANG Ju, JIANG Yun-Cheng
    Computer Engineering. 2012, 38(15): 62-65. https://doi.org/10.3969/j.issn.1000-3428.2012.15.018
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    There are two shortcomings in the traditional Ontology-based Texts Classification(OTC) research, one is the Information Content(IC) that the concepts are not taken into account, the other is that they usually ignore the importance of the ontology reasoning abilities. This paper presents a tourism domain ontology based approach for texts classification, which solves the two problems mentioned above. This approach takes the structure of ontology as classification standard, which is realized by combining the semantic correlation degree of concepts and terms and the ontology reasoning abilities. The text is classified to the ontology concepts as the individuals. Experimental results show that this approach has at least 8.7% improvement over the traditional classification method on the measure of F1.
  • SU Fan-Jun, FANG Hui-Cong, XU Jian, WU Chun-Hua
    Computer Engineering. 2012, 38(15): 66-69. https://doi.org/10.3969/j.issn.1000-3428.2012.15.019
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    Aiming at the unfair bandwidth allocation problem in Wireless Mesh Network(WMN) based on IEEE802.11 when transferring data through multi-hop, this paper proposes an improved bandwidth allocation algorithm——Detection-based Adjustment and Schedule(DBAS). DBAS detects the active end node numbers of its child nodes to calculate the allocation indexes, and then sends them to its child nodes. A child node adjusts the size of contention window of Media Access Control(MAC) level after receiving the allocation index. In addition, a modified round robin schedule algorithm is adopted when a node sends packets to its father node. NS2 experimental result verifies the effectiveness of the proposed algorithm.
  • ZHANG Meng, WANG Jing-Zhuo, DONG Zi-Jian
    Computer Engineering. 2012, 38(15): 70-73. https://doi.org/10.3969/j.issn.1000-3428.2012.15.020
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    In order to reduce node energy consumption and improve channel utilization, an energy-efficient Medium Access Control(MAC) algorithm based on cluster for Wireless Sensor Network(WSN) called EEC-MAC is proposed. It adopts time-slot factor based on TDMA to adjust slot size to reduce data transmission delay and allows a longer sleep time for the part of nodes which have no data transmission to save energy, and forms a slot order by the residual energy coefficient to reduce the state conversion energy consumption. It uses CSMA/CA mechanism to communicate with cluster heads. Simulation results show that EEC-MAC has a better energy saving, a smaller average network delay and a longer lifetime.
  • ZHANG Yan-Yu, SHU Xi-Jun, ZHANG Shui-Lian
    Computer Engineering. 2012, 38(15): 74-76,80. https://doi.org/10.3969/j.issn.1000-3428.2012.15.021
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    In traditional distributed Multiple Input Multiple Output(MIMO) system, the transmitting power is not allowed to be shared among antennas. To deal with this problem, capacity-optimal precede with per-antenna power-constrained is discussed. The optimization problem is solved by Lagrange dual optimizing procedures, the correlative algorithms and the signal emission strategy under different antenna configuration and capacity criterion are given. Simulation results indicate that the numerical capacity-optimal preceding enhances the channel capacity, compared with that of sub-optimal solution when the number of transmit antennas is more than that of receive antennas, or when the channel matrix is rank-deficient.
  • JIANG Li-Sai, CENG Ju-Ling
    Computer Engineering. 2012, 38(15): 77-80. https://doi.org/10.3969/j.issn.1000-3428.2012.15.022
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    An optimal mapping from differential service to wireless link with multiple Quality of Service(QoS) support is presented, which include two steps. The first is the optimal service category mapping from the difference service to the wireless link subjected to the packets loss ratio based on the line integer programming and its search solution. The second is to set up an optimal bandwidth allocation model for the mapped service subjected to the minimum error of the packets loss ratio and the delay based on the queue statistical flow theory and to solve the model using the steepest descent method, where the numerical description for the bandwidth gradient is used and the effect of the time variation to the bandwidth allocation is involved. Simulation results show that the mapping can make the resource consumption and the mapping error of the packets loss ratio and delay the least, and the result can be adaptive to the time variation of the link.
  • CHEN Xiao-Fang, SHU Cui-Chao
    Computer Engineering. 2012, 38(15): 81-83. https://doi.org/10.3969/j.issn.1000-3428.2012.15.023
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    A collaborative spectrum detection based on backtracking blind sparsity matching pursuit algorithm is proposed for sparse signals with unknown sparsity which the cognitive radio users receive. The algorithm can control the rapidity and accuracy of spectrum detection. It chooses the candidate set automatically, adopts staged changing process to estimate sparsity and backoff mechanism to obtain the global optimal support sets, and chooses the optimal collaborative users although SNR estimate. Experimental results show that the algorithm is superior to other algorithms in the same test conditions, and the probability of detection is increased by about 25% than the collaborative detection method of nonselective object.
  • XU Fu-Xin, SHEN Wen-Wu, LIU Yan-Qun, DAO Shao-Hua, LIU Ying, SHU Feng-Yan
    Computer Engineering. 2012, 38(15): 84-86,89. https://doi.org/10.3969/j.issn.1000-3428.2012.15.024
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    An opening experimental test system based on wireless communication is designed between the master module and the slave module, and the man-machine interface based on the LabVIEW is developed. Lots of functions for the slave machine are realized, such as real time data acquisition, transmission and storage, processing, etc. The AVR M16 is adopted as a terminal’s controller due to its strong function, good performance, small size and so on. The radio frequency module IA4432 chip is used as the wireless transceiver because of its good features, such as high level of integration, low cost, lean peripheral and so on. The degree of design difficulty is reduced and the flexibility of the system is strengthened. A series of test in a multiple experimental terminals verify the system reliability is better.
  • WANG Yan-Bin, DIAO Xiao-Dong, DIAO Xin-Wei
    Computer Engineering. 2012, 38(15): 87-89. https://doi.org/10.3969/j.issn.1000-3428.2012.15.025
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    A double-ring optical protection architecture is constructed for Ethernet Passive Optical Networks(EPON) architecture, the Optical Line Terminal(OLT), the Optical Network Unit(ONU) and all fiber links are protected by this architecture, the node-architecture, the fault-tolerant and the restoring mechanism are explained. The compared results show that, when the backbone fiber are failed, the resume time of this architecture is only 45.01 percent of ITU-T and 14.67 percent of SRA.
  • YANG Jian, LIANG Yi-Long, WANG Yong-Hua, WANG Rong-Jie, TU Song-Sen
    Computer Engineering. 2012, 38(15): 90-92,96. https://doi.org/10.3969/j.issn.1000-3428.2012.15.026
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    Based on weight adaptive optimization, a novel cooperative spectrum-sensing algorithm is proposed. According to the Signal to Noise Ratio(SNR) of each cooperative user, appropriate weight vector is chosen, reflecting each cooperative user’s contribution to the system detecting statistic. The weight vector has the ability of adaptive optimization on the principle of minimum mean square error, considering the actual SNR of each cooperative user, so that the detecting performance is improved on the condition of the low SNR users existence in cognitive network. Simulation results imply that the proposed algorithm has better detecting performance than traditional algorithm and agreeable convergence speed, on both condition of low SNR and high SNR of cooperative users.
  • GUO Shi-Xu, JIANG Jian-Zhong, LIU Shi-Gang
    Computer Engineering. 2012, 38(15): 93-96. https://doi.org/10.3969/j.issn.1000-3428.2012.15.027
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    The traditional deterministic semi-blind algorithm has low efficiency when finding the weighting parameter. This paper focuses on the deterministic semi-blind methods, and proposes a new semi-blind method based on noise subspace. Based on the classical subspace decomposition, an orthogonality property between the signal subspace and the noise subspace is exploited to build a linear system of equations; then, additional equations are derived by the referenced symbols; at last, the estimated channel is derived by least-square method. Simulation examples demonstrate the performance of the algorithm.
  • LIU Hai-Yan, ZHOU Hua-Yu, WEI De-Bin
    Computer Engineering. 2012, 38(15): 97-99,107. https://doi.org/10.3969/j.issn.1000-3428.2012.15.028
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    In order to solve the problem of poor performance of TCP-Casablanca algorithm when it is implemented in the satellite network, a new algorithm called Bias Queue Management on Sat(BQM_Sat) for the satellite network is proposed. Based on the loss discrimination algorithm, BQM_Sat can judge the bit error status of the channel according to the feedback of ACK and change the modulation mode automatically with physical layer to meet the requirements of sending rate and anti-noise performance for the transmission system. Simulation results show that BQM_Sat algorithm can significantly improve the throughput and the link bandwidth utilization of the satellite network as well as guarantee the stability of the network.
  • YANG Chun-Xia, HU Dan-Ting, HU Sen
    Computer Engineering. 2012, 38(15): 100-103. https://doi.org/10.3969/j.issn.1000-3428.2012.15.029
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    This paper uses a directed scale-free network to describe the MicroBlog users’ relationships, takes the behaviors of twitter users like the probability of opening twitter information and transmitting information, the time to check information and so on into account to construct a MicroBlog virus model. All the obtained results indicate that the behaviors of opening a twitter short link can prompt virus diffusing while the behaviors of transmitting warning information can restrain it spreading. The shorter the time to check information is, the faster virus spreads, and the earlier the time to transmit warning information is, the smaller the range of virus outbreaks is.
  • MENG Fan-Li, ZHANG Wei, WANG Hua
    Computer Engineering. 2012, 38(15): 104-107. https://doi.org/10.3969/j.issn.1000-3428.2012.15.030
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    The inherent characteristics of P2P system, such as dispersivenes, anonymity and randomness, are apt to plunge the system into attacks from Distributed Denial of Service(DDoS) on a large scale. In order to solve the problem, this paper proposes a distributive defense method. A mechanism to authorize the sending and receipt of data is constructed in the application platform, thus the node in the P2P platform can not send data to the system unless authorized by the target node and in this way the target can stay safe from the destructive data. Simulation experimental results show that the model can defend the DDoS attacks which takes advantage of the weakness of P2P software.
  • CHEN Gao, SHU Yan-Qin, LUO Chi-Shao
    Computer Engineering. 2012, 38(15): 108-110,113. https://doi.org/10.3969/j.issn.1000-3428.2012.15.031
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    Halevi’s adaptive leakage-resilient Public Key Encryption(PKE) scheme can only resist Chosen-Plaintext-Attack(CPA) but can not resist Chosen-Cipertext-Attack(CCA). This paper uses double encryption and non-interactive zero knowledge proof systems to improve the scheme, and proposes a formal definition on adaptive leakage-resilient against CCA. Based on the definition, an adaptive-resilient PKE against CCA is constructed. Security analysis shows that improved scheme has the same secret key size, and it is more secure.
  • LUO Jiang-Dan, CHU Ti-Fei, GU Chun-Xiang
    Computer Engineering. 2012, 38(15): 111-113. https://doi.org/10.3969/j.issn.1000-3428.2012.15.032
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    The time-memory trade-off method based on rainbow table method proposed by Thing can not order the stored data and remove the repeated data, therefore the disadvantages in the probability of false alarm and the cost of table searching are obvious. According to problems of Thing’s method, this paper presents a new rainbow table method based on block storage structure. By designing new table structure and table searching method, and combining the chains that have the same end point in precomputation, the possibility of false alarm is decreased and efficiency of table searching is improved. Analysis shows that the method has advantages in success rate, space utilization rate and the cost of table searching compared with the similar method.
  • SUN Ling, TIAN Yuan, GENG Hong-Zhi
    Computer Engineering. 2012, 38(15): 114-118. https://doi.org/10.3969/j.issn.1000-3428.2012.15.033
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    There are disconnection problems in Internet Key Exchange version2(IKEv2) scheme of IETF standards when nodes changing IP address during Security Association(SA) update. Mobile IKE(MOBIKE) has low efficiency and is unable to resist malicious reflection attack during SA update. So this paper presents a new management scheme by improving the creation of SA, decreasing renegotiation processing on mobile nodes SA, creating relativity between security association and mobile node’s home address. Analysis result shows that the new scheme guarantees the SA update when mobile nodes changing address off-line and behaves better in efficiency and security compared with MOBIKE.
  • HE Dun-Jie, SUN Fang, QI Chuan-Da
    Computer Engineering. 2012, 38(15): 119-122. https://doi.org/10.3969/j.issn.1000-3428.2012.15.034
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    Security analysis of designated verifier proxy blind signature scheme with message recovery which is proposed by Yu Jianying shows that the scheme exists follow security flaws: the designated verifier can impersonate proxy signer to forge proxy blind signature of any message; the proxy signer can track the message owner colluded with the designated verifier. An improved scheme which can resist the designated verifier’s forgery attack and linkability attack is proposed. Analysis result shows that the improved scheme satisfies strong unforgeability, undeniability, unlinkability and privacy.
  • ZHANG Mei-Hua, CHEN Liang
    Computer Engineering. 2012, 38(15): 123-127. https://doi.org/10.3969/j.issn.1000-3428.2012.15.035
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    In order to analyze intrusion evidences automatically, a new hierarchical forensics algorithm based on forensics graph is proposed. The status of network entities are identified by using Rule-based Fuzzy Cognitive Map(RBFCM) model, important entities are selected from forensics graph by using Eigenvector Centrality Metric(ECM), and attack groups are extracted from large part of association nodes in the attack scenario. Experiments on DARPA 2000 prove that the method achieves high accuracy in the attack group extraction and scenario reconstruction.
  • LI Ye-Da, LIU Heng
    Computer Engineering. 2012, 38(15): 128-133. https://doi.org/10.3969/j.issn.1000-3428.2012.15.036
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    In order to enhance secure level of mobile informatization access and protect business of organization running securely, based on traditional network security architecture, this paper uses Layer 2 Tunneling Protocol(L2TP) and mixed encryption technology to construct a security access platform. According the functionality and security feature of the platform, the platform is classified to 5 parts. For each area, the different security policy is deployed, so that Internal business application with high security can be safely used on the mobile devices. Application result shows that the platform guarantees anonymity of user identification, confidentiality and integrity, availability and non-repudiation of data.
  • HU Jian, YANG Geng, CHEN Zheng-Yu, WANG Hai-Yong, YANG Shen
    Computer Engineering. 2012, 38(15): 134-138. https://doi.org/10.3969/j.issn.1000-3428.2012.15.037
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    The special characteristics of Wireless Sensor Network(WSN), such as resource constraints and self-organizing nature of its architecture, introduce unique challenges for privacy preservation in WSN. The privacy-preserving aggregation techniques are classified into three categories: cluster-based, slice-based and encrypt-based depending on the protocol operation. It reviews the existing techniques for privacy- preserving data aggregation, including CPDA, iCPDA, SMART, ESPART, CDA, RCDA, KIPDA and so on, evaluates their performances in terms of several metrics, such as computation complexity, communication complexity, delay, privacy, accuracy, and then summarizes the pros and cons of each algorithm. Some important future research directions in the field of privacy-preserving data aggregation for WSN are discussed.
  • LIU Cong-Shan, LI Xiang-Bao, YANG Yu-Pu
    Computer Engineering. 2012, 38(15): 139-141. https://doi.org/10.3969/j.issn.1000-3428.2012.15.038
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    This paper proposes a novel algorithm named K-NCA based on Neighborhood Component Analysis(NCA). It uses NCA to learn a Mahalanobis distance measure and reduces the dimension of the input dataset. The algorithm defines a class imbalance factor and introduces K Nearest Neighbor(KNN) to compute the test sample’s class-conditional probability estimation. The sample’s class label is decided by this probability. A text classifier is designed to accomplish the algorithm. Experimental results show that K-NCA algorithm can improve the accuracy of text classification.
  • LIU Zhen-Hua, FU Shan
    Computer Engineering. 2012, 38(15): 142-144,147. https://doi.org/10.3969/j.issn.1000-3428.2012.15.039
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    The trajectory distribution patterns of pilot operation gesture are learned based on an improved self-organizing neural network model. Wilcoxon rank sum test and the edit distance technology are introduced to determine the matches in the internal net neighborhood, and the cross-validation technique is used to get the threshold for abnormal detection. Using the learned patterns, this paper considers both local and global anomaly detection as well as object behavior prediction. Experimental results demonstrate the effectiveness of this approach.
  • YIN Fang, CHEN De-Yun, TUN Dui
    Computer Engineering. 2012, 38(15): 145-147. https://doi.org/10.3969/j.issn.1000-3428.2012.15.040
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    Gabor wavelet transformation feature extraction method based on direction pre-classification is presented to resolve the recognition of scene text which is together with complex background, inconsistent of color, strong noise, deformation, incomplete, blur, fracture and so on. The method uses the frequency and direction selectivity of Gabor function, and fully considers the direction offset. Direction pre-classification makes the stroke direction selection more accurate. Experimental result shows the method is adaptive for character of stroke deformation or low resolution and can recognize low-quality scene text effectively.
  • ZHANG Xiao-Feng, ZHENG Dan, HUI Gui-Fang, LI Zhi-Nong, YANG Guo-Wei
    Computer Engineering. 2012, 38(15): 148-151,155. https://doi.org/10.3969/j.issn.1000-3428.2012.15.041
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    The double chains quantum genetic algorithm based on real-coded and gradient of objective function increases the diversity of population, expands the search field about space, accelerates the algorithm evolutionary process, avoids the premature convergence phenomenon, is an effective optimization algorithm, but does prove theoretically convergence. This paper gives the corresponding theorem on the basis of previous work, theoretically proves the convergence of the algorithm by the theorem, and discusses the effects of the quantum coding and quantum rotation gate in terms of the algorithm convergence and optimization efficiency by simulation example. Results show that his research enriches and improves the double chains quantum genetic theory.
  • HU Qiang-Wu, AI Meng-Yao, YAN Mo-Ling, YUAN Hui
    Computer Engineering. 2012, 38(15): 152-155. https://doi.org/10.3969/j.issn.1000-3428.2012.15.042
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    Images with large rotation angle from low altitude Unmanned Aerial Vehicle(UAV) with weakness stability cannot realize automatically mosaic using the traditional methods with geo-referenced orthographic images. In this paper, an image mosaics technique with Scale Invariant Feature Transform(SIFT) and multi-resolution spline merging is proposed for low attitude UAV images. A fast and batch image distortion correction algorithm based on single image distortion look-up table is presented for multiple images. A novel homograph-constrained image matching algorithm based on SIFT feature is proposed to calculate the optimal transformation matrix between overlapping images. A multi-resolution spline mosaics technique with optimal transformation matrix of overlap images is presented. Experimental result shows that the proposed method can obtain a large number of stable correspondences and transformation matrix of overlap images for further seamless image mosaic, which can be useful for fast and automatic images mosaic from low altitude UAV with large rotate angle and instability.
  • WANG Xing, MA Zong-Min, CHEN Ji
    Computer Engineering. 2012, 38(15): 156-158. https://doi.org/10.3969/j.issn.1000-3428.2012.15.043
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    Aiming at the problem that fuzzy rule language f-SW-if-then-unless-RL cannot interchange rules with languages in f-RIF interchange framework, a mapping between f-SW-if-then-unless-RL and f-RIF is constructed. A prototype system named Rule Interchange System(RIS) is designed and implemented to deal with f-SW-if-then-unless-RL rules and to interchange fuzzy rules between these two languages. The implemented prototype system is an important part of the f-RIF interchange framework.
  • MEI Xue, ZHANG Ji-Fa, HU Song-Song, HU Dan
    Computer Engineering. 2012, 38(15): 159-161,165. https://doi.org/10.3969/j.issn.1000-3428.2012.15.044
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    Aiming at the activities directions of human are arbitrary, this paper proposes the viewpoint independent behavior recognition method. A camera with fixed position is used to measure the motion direction based on the change of mass center coordinates in world space. According to the direction, video sequences can be selected taken by the camera which visual angle is orthogonal or parallel to the movement direction. A database on key features of motion activity sequences is taken orthogonally and parallel to the subject’s movement is established for several human behaviors indoors. The method of parallel line bound with single camera is used to reconstruct 3D coordinate of key points by image coordinate and conversion factor. The method is tested on sequences of video data of human motions indoors, and experimental results validate the good performance of the proposed approach in viewpoint independent behavior recognition.
  • GUO Jing-Ren, LUO Dian-Sheng, HE Hong-Yang, JIU Zhi-Jiang, BANG Han-Beng, ZHANG Gong-Yan
    Computer Engineering. 2012, 38(15): 162-165. https://doi.org/10.3969/j.issn.1000-3428.2012.15.045
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    Aiming at weak stability, volatility larger bus load forecasting of simple algorithm, this paper puts forward a chaos optimization combination forecasting model based on multi-neural network. This model puts the predictive value of fuzzy network, wavelet network and gray network for chaos optimization combination by the improved chaotic learning algorithm, determines the optimal weight coefficients, and gets the final prediction results. Example analysis shows that the combination model is better than a single network model and the traditional combination model, and significantly improves the precision of the load forecast and convergence speed.
  • SU Wei, WANG Ji-Dai, SUN Ai-Qin, ZHANG Dong-Yue
    Computer Engineering. 2012, 38(15): 166-168,171. https://doi.org/10.3969/j.issn.1000-3428.2012.15.046
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    Traditional inspection robots on high voltage transmission line have low intelligence and can not move steadily. In order to solve the problem, this paper proposes an expert control system based on rules. It includes the structure of the expert system, the design method of knowledge base, and uses a hybrid programming method of Visual C++ and CLIPS to build the inference engine. A motion planning for robots needs to be made, and a rules base established afterwards. Facts produced in the process of operation are taken to compare with these rules until they find the matched ones. Then the robot acts according to the matched rules. Experimental results verify the feasibility of this system.
  • LIANG Meng, HUANG Nan
    Computer Engineering. 2012, 38(15): 169-171. https://doi.org/10.3969/j.issn.1000-3428.2012.15.047
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    Aiming at the traditional methods have easy fabrication, complex recognition process etc defects, this paper proposes a pension authentication algorithm based on face recognition technology uniqueness for stability and uncontested advantages. The retirees face is collected and matched with face database in server to realize the retiree identity authentication. The algorithm is applied to pension identity authentication system. Results show that the proposed algorithm improves the pension authentication accuracy compared with other algorithms, and it can effectively prevent identity fraud.
  • LIU Bing, LI Hui, GENG Gang
    Computer Engineering. 2012, 38(15): 172-174. https://doi.org/10.3969/j.issn.1000-3428.2012.15.048
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    Different sensors provide different evidence importance in a target recognizing system with heterogeneous multi-sensor data fusion method. This paper proposes a fuzzy information fusion target recognition method. The evidences are transformed according to their weights before fused together using the Dempster-Shafer(D-S) evidence theory. The sensor measurements and data in the database are simulated by using the fuzzy mathematical model, and the mutual support degree among evidences is obtained from the evidence distances in order that the information weight of the evidence to the system is obtained. Analysis results show that this method has higher accuracy and reliability.
  • JIN Xin, LIANG Xue-Chun, GONG Ning-Sheng
    Computer Engineering. 2012, 38(15): 175-178. https://doi.org/10.3969/j.issn.1000-3428.2012.15.049
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    In order to solve the problem about multitarget tracking, this paper proposes a new video-based traffic tracking counting method. The frame difference method is used to extract the moving target and the image needs morphological processing. Connected domain analysis is applied to create the human node and get the node’s centroid. According to the nodes’ centroids which are created in the list, first search forward is used. All target pixels are searched in the next frame which are used to determine the new position of the object in the video. Experimental results show that the method is simple and feasible, and achieves statistical data with high accuracy.
  • HU Xiao-Xia, YANG Tu-Wang, MO Ran
    Computer Engineering. 2012, 38(15): 179-182,186. https://doi.org/10.3969/j.issn.1000-3428.2012.15.050
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    Based on the digital video developing platform SEED-DEC643 and the camera FCB-CX1010P, this paper proposes an algorithm of moving target detection. It realizes the single moving target detection under the static background, including image preprocessing, background subtraction, the fetching of threshold, image binarization, morphological image processing and the calculation of the moving target coordinates. This paper utilizes the gray projection algorithm to calculate the motion vectors, then realizes motion compensation and the single moving target detection under the dynamic background. Experimental results show that this algorithm can get well background motion compensation, and highlights the moving targets.
  • HONG Tan-Feng, CHEN Yao-Wu
    Computer Engineering. 2012, 38(15): 183-186. https://doi.org/10.3969/j.issn.1000-3428.2012.15.051
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    In order to meet the demands of real-time statistics for classification, this paper proposes a design for real-time intelligent recognition system of plankton target with high recognition rate. This paper acquires real-time image with CCD sensor, develops target frame selection in the processing of frames. A fast segmentation based on background subtraction instead of traditional iteration is proposed. Fast linear classifier with adaptive feature extraction is achieved for target classification. At the same time, this paper achieves parallel processing with load balancing. Experimental results show that the system reaches real-time recognition while average single-frame recognition time is less than 29.1 ms and recognition rate is as high as 91%.
  • WANG Zhen-Yu, TUN Ze-Heng, HU Fang-Chao
    Computer Engineering. 2012, 38(15): 187-189,193. https://doi.org/10.3969/j.issn.1000-3428.2012.15.052
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    The polarity calculation of word level is the basis of sentiment analysis of sentence level and discourse level. The traditional calculation methods based on Point Mutual Information(PMI) or HowNet have their own defects: methods of PMI depend on the perfection of the corpus, and methods of HowNet depend on accuracy of the similarity calculation based on HowNet. In order to improve these deficiencies, an improved method for calculating the polarity of words is proposed, combining HowNet with PMI. First of all, HowNet is used to expand the synonyms of the emotional words in order to reduce the impact of some emotional words which have low frequency in the corpus, and then, according to the similarity calculation based on HowNet, it integrates the similarity based on HowNet with that of PMI. Experimental results show the new method increases micro average and macro average by 5% compared with traditional methods.
  • LIU Chao-Jie, ZHANG Chao, HU Fu-Jiao, LIAO Ping
    Computer Engineering. 2012, 38(15): 190-193. https://doi.org/10.3969/j.issn.1000-3428.2012.15.053
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    To address the issue that more and more requirements to the multi-objects detection and tracking technology, this paper proposes a real time multi-objects tracking algorithm in traffic scene. It designs background modeling algorithm and the dynamic multi-level tracking algorithm based on corners. Background modeling algorithm is used to extract the foreground. Tracking algorithm has three levels which are Corner, Cluster and Object. It introduces suitable grouping algorithm to the different layers to realize object tracking. Experimental results show that the proposed method can be applied to most traffic scenes. It is robust to light and shadow and to the multi-objects tracking with complex background.
  • XIANG Zheng, TAN Heng-Liang, MA Zheng-Ming
    Computer Engineering. 2012, 38(15): 194-196,200. https://doi.org/10.3969/j.issn.1000-3428.2012.15.054
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    This paper describes the face recognition algorithm of Histograms of Oriented Gradients(HOG), and designs face recognition experiment based on HOG. The Experiment is done on the Face Recognition Technology(FERET) face database. It testes the effect of different HOG parameters on face recognition and tries to find the optimal parameter settings. Experimental results show that the choice of space and range in gradient direction of HOG feature is the same on pedestrian detection and face recognition. The different block mode has different effects too. HOG descriptor can express face effectively when it produce less characteristic dimension in non-overlapping manner. Recognition performance improves significantly when it is standardized.
  • PENG Tong, CENG Qiang-Hua, LIU Jian-Ye, DONG Liang
    Computer Engineering. 2012, 38(15): 197-200. https://doi.org/10.3969/j.issn.1000-3428.2012.15.055
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    To get the attitude of the Unmanned Air Vehicle(UAV) in the process of continuous flight, an attitude algorithm of Micro-unmanned Air Vehicle(MUAV) based on monocular vision is introduced in this paper, by capturing the sequence images with monocular vision of unmanned camera, obtaining the feature points information with using Scale Invariant Feature Transform(SIFT) algorithm, based on epipolar geometry and Random Sample Consensus(RANSAC) method, the attitude transform information and navigation information of MUAV are resolved. Experimental results show that in proper environment with good matching points state, the attitude transform error with monocular vision is less than 0.1 degree, and accumulated attitude error within 180 degree rotation range is less than 1 degree.
  • XIE Jing, XU Chang-Hang, CHEN Guo-Meng, WANG Yu
    Computer Engineering. 2012, 38(15): 201-203,207. https://doi.org/10.3969/j.issn.1000-3428.2012.15.056
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    Imaging principle and environment disturbance have lowered the definition of the infrared thermal image. Aiming at this problem, an infrared thermal image processing framework is proposed based on Fuzzy C-means(FCM) clustering algorithm with spatial and frequency information. A sequence of preprocessing is applied to the original infrared thermal image. FCM with spatial and frequency information is used on the preprocessed image to segment defect and normal surface of a part. Experimental results show that the proposed infrared thermal image processing framework is very effective to detect the surface defect of a metal part.
  • CHENG Jing, HE Hong, FANG Chao
    Computer Engineering. 2012, 38(15): 204-207. https://doi.org/10.3969/j.issn.1000-3428.2012.15.057
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    A novel change detection method based on topic model is proposed for high resolution remote sensing images. It takes every pixel pairs of the bi-temporal remote sensing images as a basic unit, and extracts their low-level features, such as the relevacy, mean value, standard deviation of neighbor brightness, the slope and intercept of neighbor regression line. Then the high-level visual words mapped by theses low-level features are generated. After that, by utilizing the classical topic model of Latent Dirichlet Allocation(LDA) to analyze, the latent topic information is to be found, that is, changed or unchanged, thereby the goal of change detection is achieved. Experimental results show that this method can effectively detect changes in high resolution remote sensing images.
  • JU Hun, WO Yan, ZHANG Jian-Wei
    Computer Engineering. 2012, 38(15): 208-210,214. https://doi.org/10.3969/j.issn.1000-3428.2012.15.058
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    A solid texture synthesis algorithm is proposed to synthesize layered textures which have varying statistical features along the depth direction. It employs the global optimization-based synthesis framework. In preprocessing, a feature distribution map that reflects the varying statistical features along the depth direction of the sample is generated, and it is involved in the similarity measurement. During synthesis, the neighborhood similarity in three orthogonal directions is considered, and k-coherence search is utilized in the iterative optimization. Experimental results show that the algorithm can produce high quality results which bare reasonable feature distributions both along the depth direction and in horizontal slices, and it converges quickly.
  • XIANG Yang, CHONG Yan-Wen, WANG Yi-Nuo, BO Shao-Meng
    Computer Engineering. 2012, 38(15): 211-214. https://doi.org/10.3969/j.issn.1000-3428.2012.15.059
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    Against the problem that the method of color coherence vector is easy to lose the spatial information of image content, a new method for image retrieval is proposed in this paper. It introduces the feature of narrow degree and standard deviation, proposes a new method for image block-dividing, the concept of centrifugal distance and a new distance formula. Specific practices are as follows. It extracts the feature of size, narrow degree and color of color connected regions. It extracts the number of pixels, the standard deviation and centrifugal distance of the image. It calculates the content similarity between images and retrieval. Experimental results in Corel image database show that this method can effectively use the spatial distribution information of the image, and accuracy is increased.
  • JU Xiao-Lin
    Computer Engineering. 2012, 38(15): 215-217,221. https://doi.org/10.3969/j.issn.1000-3428.2012.15.060
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    Min-max cut(Mcut) algorithm completely satisfies the general criterion of the cluster algorithms, so Mcut has good grouping performance. However, in the actual solution, the objective function of Mcut usually is relaxed into the objective function of Normalized cut(Ncut). It does not make full use of the clustering performance of Mcut. In order to overcome this problem, this paper presents an improved Mcut algorithm(SMcut) that uses subspace technology. In order to improve SMcut’s speed in image segmentation, a SMcut based on block(BSMcut) is proposed. Experimental result shows that SMcut and BSMcut has better segmentation performance, at the same time, BSMcut can reduce the computational complexity.
  • HUANG Ge-Kun
    Computer Engineering. 2012, 38(15): 218-221. https://doi.org/10.3969/j.issn.1000-3428.2012.15.061
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    In order to raise the performance of Set Partitioning in Hierarchical Trees(SPIHT) algorithm and maintain the encoding speed, an improved SPIHT algorithm based on binary tree is proposed. Four coefficients splited by D-type sets are coded by binary tree. Through coding the significance of L-type sets first, the algorithm can determine the significance of the root of the binary tree in advance with high probability, so as to further improve the coding efficiency. Experimental results show that the speed of the proposed algorithm is as fast as SPIHT algorithm, and it can improve Peak Signal to Noise Ratio(PSNR).
  • LIU Chun-Mei, JU Chuan-Yun, CAO Wen, XU Lei
    Computer Engineering. 2012, 38(15): 222-224,227. https://doi.org/10.3969/j.issn.1000-3428.2012.15.062
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    To reduce the edge sawtooth and blur of image during the digital image interpolation, an image interpolation algorithm based on Pulse Coupled Neural Network(PCNN) is introduced. The clusters and the propagation paths of pulse are obtained by using the synchronous pulse burst property of PCNN, then the different interpolation method is used in the inner and intervals of clusters to finish interpolation of the whole image. Experimental results show that the visual effect of interpolation algorithm is much better than that of the bilinear and spline algorithms, and the Peak Signal to Noise Ratio(PSNR) is increased by more than 0.2 dB.
  • HU Lin, HU Chao-Xiang
    Computer Engineering. 2012, 38(15): 225-227. https://doi.org/10.3969/j.issn.1000-3428.2012.15.063
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    Generalized Auto-calibrating Partially Parallel Acquisition(GRAPPA) algorithm assumes that the reconstruction kernel is shift invariant in the whole K-space, it often generates artifacts and noise in the clinic. Aiming at this problem, this paper proposes an GRAPPA reconstruction algorithm based on anisotropic diffusion. It is used to remove the noise and the singular point in K-space data, while maintaining the phase information, making the reconstruction more accurate. Vivo experimental reconstruction demonstrats that the proposed algorithm can reduce noise and artifacts at any under-sampling condition, and gets higher quality data reconstruction.
  • ZHANG Li-Na, LI Xiao-Lin
    Computer Engineering. 2012, 38(15): 228-229,233. https://doi.org/10.3969/j.issn.1000-3428.2012.15.064
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    Since the model combining image decomposition with edge extraction is not good enough in processing complex image, this paper proposes an improved model. The diffusion tensor by Weickert(International Journal of Computer Vision, 1999, No.2) is used to improve edge b regularization of the model, enabling respectively in the gradient direction and along the edge direction to control the edge b diffusion rate. Experimental results show that the improved model can improve the edge extraction accuracy, and reduce the singularity.
  • XIE Hui, LIU Liu, LI Jian-Xun
    Computer Engineering. 2012, 38(15): 230-233. https://doi.org/10.3969/j.issn.1000-3428.2012.15.065
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    Due to prominent distributional variations of grayscale between multi-source images, traditional image matching methods rooted in grayscale correlations exhibits limited effectiveness on infrared and visible images matching problems. To avoid undependable grayscale correlations, a local structure-based infrared visible image matching method is presented. Harris corner and its neighbor contour segments oriental angles are combined to build Local Oriented Harris Feature(LOHF), affine estimation is derived based on LOHF, and feature matching is realized by point set matching hypothesis-verification combined with RANSAC robust estimation. Experimental results show the capability of proposed method when other methods are failure on infrared visible image matching task.
  • CHANG An-Hui, SHU Dan-Jian, LOU Jing-Dun
    Computer Engineering. 2012, 38(15): 234-236. https://doi.org/10.3969/j.issn.1000-3428.2012.15.066
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    The synchronization of Duffing chaotic systems with uncertainty by sliding mode control is discussed. By choosing an appropriate sliding mode surface, a fuzzy-variable structure controller and adaptive update laws are designed to achieve synchronization based on the Lyapunov stability theory, and the stability of the control system is proved theoretically. This controller is based on adaptive fuzzy sliding mode. In contrast to custom methods, sliding mode of this controller is free from the influence of disturbances, and the system has both better robustness and quick tracking. Synchronization simulations results show the effectiveness of the system.
  • YANG Meng-Hua, DAO Ling-Jiao, YANG Bin, YANG Yin-Gang, CHENG Bin
    Computer Engineering. 2012, 38(15): 237-239,243. https://doi.org/10.3969/j.issn.1000-3428.2012.15.067
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    Aiming at the requirement that security and reliability is very high, this paper designs a high-confidence fault-tolerant computer system to combine trusted computing and high-reliability technology. Depending on technology of trusted computing, password support system is constructed based on TCM to achieve platform integrity, identity authentication and data security. Depending on fault-tolerant technology, system provides uninterruptable service in an error case. The prototype system is tested by experiment, and technical program is verified to be effective.
  • WEI Jian-Gang, ZHANG Xi-Huang
    Computer Engineering. 2012, 38(15): 240-243. https://doi.org/10.3969/j.issn.1000-3428.2012.15.068
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    The biological mechanism, main steps and applicable environment of Dendritic Cell Algorithm(DCA) are described and introduced. Through analyzing the characteristics of real-time task, the required parameters are abstracted and given. Experiment results show that DCA can accurately detect overtime exception appeared in real-time task compared with traditional methods. In addition, this method can provide basis for processing the exceptions.
  • XU Yao-Song, LI Yi-Bo, FU Tong-Ling, JIN Shi-Jiu
    Computer Engineering. 2012, 38(15): 244-246,250. https://doi.org/10.3969/j.issn.1000-3428.2012.15.069
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    A Principal Component Analysis(PCA) based acoustic ranging method is proposed for conducting feature extraction and dimension reduction. The method is used to suppress multipath effect interference and preserve enough information about the covariance matrix of the received signal. Experimental results show that the method can improve the accuracy and robustness of underwater ranging in confined closed environment.
  • GAO Xin-Wen, GUAN Xin-Jian
    Computer Engineering. 2012, 38(15): 247-250. https://doi.org/10.3969/j.issn.1000-3428.2012.15.070
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    Combined with gray theory and Kalman filter prediction method, this paper proposes a new Gray Kalman Filtering(GKF) method to predict the ground subsidence, which utilizes the relationship between the displacement of inclinometer supporting structure and ground subsidence. The new model is verified by Ningbo metro engineering using the comparison between actual monitoring data and predicted results. To test the effect of GKF prediction method, it uses residual test method and the results show that GKF method achieves high accuracy in predicting the ground subsidence of foundation pit excavation.
  • CHEN Xing, SHI Zai-Feng, TAO Su-Yang, ZHANG Zhi-Ku
    Computer Engineering. 2012, 38(15): 251-253,257. https://doi.org/10.3969/j.issn.1000-3428.2012.15.071
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    In order to cover all the combinations of input and output standard quickly and speed up the verification progress of multi-standard video post processing chip, a verification method of chips based on resembling directed test is proposed by using Constrained Random test(CRT) and Coverage Convergence Technology(CCT) as the guidance, then the essay specifies the process of weight correction in resembling directed test. The simulation data and experimental results show that this approach can improve the rate of hitting the blind spots of coverage, and reduce the repetition of configuration. Accordingly, the coverage of the combinations of input and output standard converges fast, and the efficiency of verification increases by 60% to 70% compared with traditional method.
  • RUAN Qun-Sheng, LI Shu-Ying, GONG Zi-Jiang
    Computer Engineering. 2012, 38(15): 254-257. https://doi.org/10.3969/j.issn.1000-3428.2012.15.072
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    Aiming at the deficiencies of the traditional features of navigation path about ships collision in the sea and the algorithm limitations for forecasting collision point, a new calculation method based on least square method of ships collision point is proposed. According to the former Global Position System(GPS) navigation data and the Mercator projection transformation, navigation track function is gained in Cartesian coordinates. The point of the intersection navigation track of two ships is identified as the possible collision point, when the ships speed and dangerous distance threshold are taken into account. The results of the numerical simulation analysis and practical application show that the method runs correctly, it is practical and can successfully avoid the limitations of the traditional method.
  • CHEN Xiang-Xian, GUO Qiang, HUANG Hai
    Computer Engineering. 2012, 38(15): 258-259,275. https://doi.org/10.3969/j.issn.1000-3428.2012.15.073
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    This paper designs a new dual-duplex safety-critical computer system used in the rail transport system including I/O module, CPU module and switch module. In the I/O module, the dynamic circuit design can make it achieve safe input and output data. In the CPU module, this paper presents a synchronization vote program based on Ethernet communication. In the switch module, it implements seamless switch by loop control. It is shown through functional and safety test that the dual-duplex safety-critical computer system can meet the needs of computer platform with high reliability and security.
  • DI Yan, WEI Zhen-Chun, HAN Jiang-Hong, WEI Xing
    Computer Engineering. 2012, 38(15): 260-263. https://doi.org/10.3969/j.issn.1000-3428.2012.15.074
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    In order to tackle the End of Life(EOL) test problem of Electronic Control Unit(ECU) equipped with communication bus, this paper designs an integrative system platform for electrical testing and brings out a scheme describing how to compile and implement the structured script language for test cases. Test objects are subdivided and classified. Test system and its workflow are put forward, which comprise ECU under test, test board, and tester. Test cases are regularly described by script language whose syntax is modeled and analyzed by finite state machine method. It gives an example that how to test one programmable port of multiple switch detection interface MC33972. Besides commonality and portability, the proposed design scheme can help to enhance the efficiency and reliability of the EOL test.
  • HUA Kai-Qing, WANG Lin
    Computer Engineering. 2012, 38(15): 264-267. https://doi.org/10.3969/j.issn.1000-3428.2012.15.075
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    Aiming at the camera calibration in the drawing of the scene for the road traffic accident, a method for camera calibration based on planar template is proposed in this paper. Initial values are computed in the image central area where the distortion is small, partial calibration values are calculated through a subspace trust region method based on the interior-reflective Newton method, by introducing distortion model and employing linear feature constrain approach, remaining parameters can be calculated. Experimental results show that the proposed method simplifies calibration process, reduces computation and improves computing speed.
  • DAO Xiang, LIN Bu-Ting
    Computer Engineering. 2012, 38(15): 268-270. https://doi.org/10.3969/j.issn.1000-3428.2012.15.076
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    Evidence theory produces counter-intuitive conclusion when the high conflict information exists. On the basis of analyzing and comparing a few improved combination rules, this paper presents a new combination rule based on partial conflict allocation strategies. It considers actual ratio of evidence as weight coefficient and redistributes the partial conflict into focal element which invokes conflict. Experimental results show that even in the case of high degree of evidence conflict, the new combination rule still can achieve the ideal synthesis result.
  • YANG Xiao-Hui, FENG Zhi-Yong
    Computer Engineering. 2012, 38(15): 271-275. https://doi.org/10.3969/j.issn.1000-3428.2012.15.077
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    Based on the abstraction of Agent from inside and outside, this paper proposes a Service-oriented Social Agent Architecture Model(SAAM) and a Service-oriented Agent Interaction System(SOAIS). Through the separation between function layer and knowledge layer, a control mechanism using descriptions is implemented. Aiming at Agent service interactions, the stages of interaction are divided into types of service find, service negotiation, service coordination, service execution and service organization. A blackboard structure is used to integrate the modules to deal with above mentioned stage interactions. Analysis results show that this model and interaction system can greatly exploit the semantics of services, and thus, a systematic and engineering method of Agent application development is provided.
  • JING Sai-Yuan, SHE Kun
    Computer Engineering. 2012, 38(15): 276-278,282. https://doi.org/10.3969/j.issn.1000-3428.2012.15.078
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    Since current researches on energy efficient consolation in data center only consider part of energy consumed by servers, this paper proposes a novel method considering both servers and network devices. The proposal achieves energy minimization by minimizing the active servers and network devices through analyzing the net topology. Moreover, the problem is modeled and a hybrid particle swarm algorithm called HPSO-NA is designed to implement virtual machine consolidation. Experimental results show that the proposed method can effectively reduce the energy consumption.
  • LI Gao-Ming, HE Yi-Gang, FANG Ge-Feng
    Computer Engineering. 2012, 38(15): 279-282. https://doi.org/10.3969/j.issn.1000-3428.2012.15.079
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    An analog circuit fault diagnosis system is designed based on information fusion and neural network theory. By measuring accessible node voltages and peak of output voltage under different excitation frequencies with microcontroller-based signal acquisition system, two types of fault characteristic parameters of voltage and magnification are acquired. Preliminary diagnosis is performed separately by BP neural networks with these two characteristic parameters. Fused diagnosis and fault location is accomplished by using fuzzy transform method. Experimental results show that this system can locate different types of component fault with higher accuracy compared with diagnosis system based on single test information.
  • XIAO Rui-Jin, QUAN Heng, ZHANG Jia-Jie, YOU Kai-Di, YANG Pan, YU Zhi-Yi
    Computer Engineering. 2012, 38(15): 283-285,289. https://doi.org/10.3969/j.issn.1000-3428.2012.15.080
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    Concerning the issue of limited number of register files in processor, this paper presents an extended register file design scheme for multi-core processors. A multi-bank architecture is employed for hardware design, and the communication ports are mapped in the address space of extended register file, which enables an inter-core communication method with register file direct addressing. A hybrid software configuring method is proposed with both bottom-layer instructions and top-layer packaged functions, and the compiling flow is improved. Estimation result shows this scheme can both double the number of available register files and reduce the number of instructions for inter-core communication by 50%. And the system throughput is optimized.
  • LIN Dao-Miao, GU Hui
    Computer Engineering. 2012, 38(15): 286-289. https://doi.org/10.3969/j.issn.1000-3428.2012.15.081
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    Program understanding is the technology that computer analyzes source code automatically and obtains the knowledge of program structure, an algorithm that represents program function with N-S figure is proposed for the analysis of program structure that belows the function level, based on the information extraction technology and the computer visualization technology. The method resolves the problems of graphical design, graphical zoom, graphical localization, graphical nested and so on. Experimental results show that it can generate N-S figure quickly and effectively, thus help the developers better understand the program source code efficiently.
  • ZHANG Gan-Dong, HE Meng-Min
    Computer Engineering. 2012, 38(15): 290-292,封三. https://doi.org/10.3969/j.issn.1000-3428.2012.15.082
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    The lock-bit anti-collision algorithm based on state arbitration is proposed on the basis of dynamic and back-binary algorithm. This algorithm coalesces lock-bit and multi-state ideas. It estimates searching cards by lock-bit, and does state segmentation of card number in the search process, and can arbitrate two states to direct the two cards for data operation. This paper uses of identification number and bit number of transmission to complete algorithm performance analysis. Simulation results show that the algorithm can reduce identification number, bit number of transmission, and retrench search time.