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05 November 2009, Volume 35 Issue 21
    

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  • LIAO Wei; LIU Jin-gao
    Computer Engineering. 2009, 35(21): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2009.21.001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To improve the decoding performance of Low Density Parity Check(LDPC) code, an efficient decoding algorithm based on min-sum algorithm is proposed. The proposed algorithm analyzes the check node update equation and at the view of probability to form an approximation min-sum equation. It adopts a dynamic normalization factor to improve the decoding performance. Detailed simulation results and comparisons with Belief Propagation(BP) algorithm show that, with little decoding performance loss, the proposed algorithm not only decreases computational load, but also improves decoding efficiency.
  • YIN Zhao-tao; LI Tie-ke; XIAO Yong-jun
    Computer Engineering. 2009, 35(21): 4-6,9. https://doi.org/10.3969/j.issn.1000-3428.2009.21.002
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    Aiming at Flowshop scheduling problem with limited waiting time, a Hybrid Genetic Algorithm(HGA) combined with constraint satisfaction and variable neighborhood search is proposed. Based on constraint satisfaction, job starting time is repaired by recursive backtracking and constraint propagation in order to solve the violated waiting time constraints. The crossover and mutation are designed according to the job backtracking positions. The convergence is enhanced by variable neighborhood search. Simulation experiment shows that the HGA is effective and analyzes the influence of upper bound of waiting time on the objective.
  • LIU Hua-lin; YANG Guang
    Computer Engineering. 2009, 35(21): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2009.21.003
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    In order to solve larger workload problems when Kernel Nearest Feature Line(KNFL) and Kernel Nearest Feature Plane(KNFP) classifiers compute large data size and high dimensionality, an improved strategy for these two classifiers is proposed according to locally nearest neighbor rule, which reduces the disabled possibility, and promotes the algorithms real-time performances under condition of similar recognition rate. It is tested by using the real range profiles of three types of aircrafts. Experimental results show this strategy is effective and feasible.
  • ZHAO Geng; WANG Bing; YUAN Yang; WANG Zhi-gang;
    Computer Engineering. 2009, 35(21): 10-12,1. https://doi.org/10.3969/j.issn.1000-3428.2009.21.004
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    In the light of the inadequate of the sequence which produced by LFSR, this paper proposes a sequence encryption method based on chaos. A Legendre sequence is used as the parameter sequence and the perturbation sequence. B-M algorithm is used to analyze the linear complexity of the new chaotic sequence. The computer simulation results show that the chaotic sequence has better linear complexity properties than original method. This method is fairly good in security and can be implemented easily in software.
  • LIU Jian-bin
    Computer Engineering. 2009, 35(21): 13-16. https://doi.org/10.3969/j.issn.1000-3428.2009.21.005
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    Aiming at common problems such as separate representation, poor efficiency and quality, difficult maintenance existed in traditional programming technologies for a long time, this paper proposes a kind of multi-phrase program procedure representation model across the analysis, design and implementation phrases with the architecture of three abstract views at conceptual, logical and implementing level, and two-level mappings on the control flow and data flow, and its views derivation approaches for the procedure blueprint. By means of establishing mapping constraint rules and corresponding relationship among the views, the procedure blueprint not only realizes association and unification of the outer views, but also assures validity and consistency of the derived artifacts, normalizing incremental, iterative and step by step refinement model-driven programming process, and improving productivity and maintainability of program effectively.
  • CHEN Kai
    Computer Engineering. 2009, 35(21): 17-19. https://doi.org/10.3969/j.issn.1000-3428.2009.21.006
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    This paper introduces a new ensemble algorithm, SER-BagBoosting Trees ensemble algorithm, which is a combination of tree predictors and is based on variational similarity cluster technology and greedy method, and it is combined with the features of Boosting and Bagging. Compared with a series of other learning algorithms, it often has better generalization ability and higher running efficiency.
  • XIE Hong-wei; LUO Yan-hua
    Computer Engineering. 2009, 35(21): 20-22. https://doi.org/10.3969/j.issn.1000-3428.2009.21.007
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    Aiming at the problems of lower precision of solution and the lower speed of convergence in relevant algorithms for DNA Sequencing By Hybridization(SBH) problem, this paper makes a model for SBH problem and extracts the heuristic information. An Improved Parallel Ant Colony Optimization(IPACO) algorithm is proposed for DNA SBH. Simulation experimental results show this algorithm has better performance compared with serial ACO, tabu search and evolutionary algorithm in precision and convergence.
  • ZHOU Guo-liang; CHEN Hong; WANG Shan;
    Computer Engineering. 2009, 35(21): 23-25. https://doi.org/10.3969/j.issn.1000-3428.2009.21.008
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    The What-if analysis in Main Memory On Line Analytical Processing(MMOLAP) environments is discussed. The expression form and original operating of what-if analysis in OLAP are formulated. On this basis, an algorithm for dynamically creating HCube or VCube with users query is proposed, Which supports multi-edition What-if analysis. The system structure is introduced, and the a type of proto-system is implemented.
  • FAN Tang-huai; XIAO Xian-jian; YIN Ling-ling; XU Li-zhong
    Computer Engineering. 2009, 35(21): 26-28,3. https://doi.org/10.3969/j.issn.1000-3428.2009.21.009
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    An adaptive and distributive Cellular Automata(CA) machine self-organization algorithm is proposed in Wireless Sensor Network(WSN). Each node of the network is assumed to be equipped with CA machine, which controls the decision on its state transition (active/standby) at different time, and avoids frequent communication with its neighbors. The power consumption is reduced. Simulation experimental results show this algorithm has stronger target detection capability.
  • Software Technology and Database
  • YAN Bo; SANG Jun; XIANG Hong; HU Hai-bo
    Computer Engineering. 2009, 35(21): 29-32. https://doi.org/10.3969/j.issn.1000-3428.2009.21.010
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    In order to study the consistency between software dynamical architecture and static architecture, software dynamical architecture needs to be obtained. To solve this problem, this paper advances a set of mapping rules, which map system running events into software architecture components. Colored Petri nets and state machine are used to formally describe this set of mapping rules with a Java program. The similarities and different application fields of the two methods are concluded.
  • CHEN Jian-min; SHU Hui; XIONG Xiao-bing
    Computer Engineering. 2009, 35(21): 33-35. https://doi.org/10.3969/j.issn.1000-3428.2009.21.011
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    This paper designs and implements an approach of Fuzzing test based on symbolic execution. The path constraints are collected and generated through code instrumentation during the application execution, and new path constraints are generated with a search algorithm and solved, which constructs new inputs that can steer the application to follow alternative execution paths. An improved taint analysis mechanism is presented to optimize the path constraints. This approach improves the code coverage and the vulnerabilities exploiting efficiency.
  • KANG Xiao-wen; YANG Ying-jie; DU Xin
    Computer Engineering. 2009, 35(21): 36-38,4. https://doi.org/10.3969/j.issn.1000-3428.2009.21.012
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    Based on the analysis of virtual storage technology and its application in disaster tolerant system, this paper designs a virtual file system which is adapted to disaster tolerant system. This system bases on Windows platform, and adds a filter driver layer in Windows storage stack to implement the isolation between file system and volume manager. It implements virtual storage mapping mechanism which is adapted to disaster tolerant system in filter driver layer.
  • YANG Yi-fu; LIU Yan-bing; LIU Ping; GUO Li
    Computer Engineering. 2009, 35(21): 39-41. https://doi.org/10.3969/j.issn.1000-3428.2009.21.013
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    Automaton is one kind of data structure often being used in string matching algorithms. By realizing compact representation of automaton, the algorithm space can be decreased. This paper summarizes several frequently used compact representations of automaton, analyzes their principles, time efficiencies, space efficiencies, merits and demerits, and gives relationships between above methods and sparsity character. It implements the basic AC algorithm with compact representation method. Experimental results of random and real data demonstrate the efficiency of this algorithm.
  • QIAN Jian-ping; SHEN Bei-jun; CHEN De-lai;
    Computer Engineering. 2009, 35(21): 42-44,4. https://doi.org/10.3969/j.issn.1000-3428.2009.21.014
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    This paper studies and develops a development tool for service component of model drive, and presents the relevent development flow of these service components. Based on Service Component Architecture(SCA), this tool defines the component model, validates the correctness of the model, and generates the code skeleton by using model drive development technology. The tool supports the three key procedures of component development——components making, components composition and components management. Practice results show that this tool can increase the software development efficiency.
  • ZHANG Rui; LIU Xiao-xia
    Computer Engineering. 2009, 35(21): 45-47. https://doi.org/10.3969/j.issn.1000-3428.2009.21.015
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    Interaction filtering algorithm based on use case diagram uses matrix operation to filter interaction by describing call flow with use case diagram. In order to solve the problems of large time consumption for matrix operation and of low filtering efficiency in original algorithm, this paper adds pre-conditions to filter feature combinations that will not conflict, and reduces the combinations of uncertain types, so that filtering efficiency of the algorithm is improved. The algorithm is compared with another improved interaction filtering algorithm.
  • LI Wen-jing; LIAO Wei-zhi; WANG Ru-liang
    Computer Engineering. 2009, 35(21): 48-50,5. https://doi.org/10.3969/j.issn.1000-3428.2009.21.016
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    According to Petri nets system for parallel control and implementation, Petri nets system function partition and its parallel algorithm is put forward. The place-invariants technology of Petri nets for function division is adopted to get the function parting algorithm of Petri nets based on non-negative place-invariants. After the analysis of the parallelism of the internal and in-between process, the parallel algorithm and its application example of Petri nets are given in message passing interface. Experimental results show that the algorithm can better reflect actual running process of Petri nets and it is a feasible and effective method for Petri nets system to achieve parallel control and running.
  • JIANG Hong-chao; WANG Da-liang; BAN Xiao-juan; RUAN Jin-xi
    Computer Engineering. 2009, 35(21): 51-53. https://doi.org/10.3969/j.issn.1000-3428.2009.21.017
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    It is an important aspect of data extraction and mining that how to exactly gain and chronically trace the content regarded by users on Internet with huge information. This paper discusses Web data extraction theories and its application technologies, gives a sime-automatic extraction model, and designs a extraction system based on tourism industry data to prove the feasibility data sime-automatic extraction.
  • YU Quan-xi; ZHANG Yi-kun; HU Yan-jing; ZHU Wei
    Computer Engineering. 2009, 35(21): 54-56,5. https://doi.org/10.3969/j.issn.1000-3428.2009.21.018
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    This paper depicts embedded software dynamic test characteristic and path coverage test strategy to design a data collection and processing framework, which includes program instrumentation, data collection, data transmission and results processing. The results of static analysis show instrumentation, using message queue to collect and transmit data, and making rudimental report based on the results. Through simulated collection and processing data of a path, the feasibility of the framework is proved.
  • LIU Yi; ZHANG Kan
    Computer Engineering. 2009, 35(21): 57-59. https://doi.org/10.3969/j.issn.1000-3428.2009.21.019
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    Aiming at the problem of task assignment in Workflow Management System(WfMS), this paper presents a strategy for task assignment which supports load balance of task actors and experiential value, and bridges the gap between roles and task actors. On the basis of predicting the load of task actors, the strategy takes the following factors into account: the working load of task actors, the quality achieved by them and their interest of different categories of tasks. According to the prediction of load deviation, the load of task actors is divided into several sets, and the task is assigned to the actor who has the highest experiential value in light load set.
  • YU Bo; KONG Liang; PENG Chen
    Computer Engineering. 2009, 35(21): 60-61,6. https://doi.org/10.3969/j.issn.1000-3428.2009.21.020
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    For testing Web services automatically, the method testing Web service based on algebraic specification is proposed. The algebraic specification language ASOWS for describing Web service is represented. The test cases are automatically generated based on algebraic specification of Web service according to the method coverage criterion and the equation coverage criterion. The prototype tool for testing Web service is implemented. Experimental result shows that the method can be applied to test Web service automatically deployed on Web application server.
  • YU Yuan; QIAN Xu; ZHONG Feng; LI Xiao-rui
    Computer Engineering. 2009, 35(21): 62-64. https://doi.org/10.3969/j.issn.1000-3428.2009.21.021
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    Aiming at the problems during construction process of increment concept lattices such as low efficiency of nodes updating and generation element judgement, this paper presents an increment construction algorithm for concept lattice based on maximal concept which reduces the judgement process of generation element by tracking the largest concept with same connotations of concepts in concept lattice. The algorithm limits the search space while searching the father node of a new generated node, avoids judging unnecessary borders of generation element and improves the speed of concept lattice construction. Complexity analysis results demonstrate that this algorithm has better time performance than other kindred algorithms.
  • LI Juan; WANG Hou-xiang; JIAO Zhi-qiang
    Computer Engineering. 2009, 35(21): 65-66,7. https://doi.org/10.3969/j.issn.1000-3428.2009.21.022
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    Aiming at the middle-aligned problem between logic service and physics service in the development of the service-oriented dynamic ERP system, a middle-aligned method for service concept twoness is provided including description of structural consistency and subjection relation for content. An applied instance of this method from processes of services classification, services exposure, and service implementation, to deal with the stock management domain in the dynamic ERP is presented. Simulation experimental results show this method can transform candidate logic services to physics services seamlessly which perfects the Service-Oriented Architecture(SOA) life cycle model in the dynamic ERP system.
  • ZHANG Long-jie; XIE Xiao-fang; YUAN Sheng-zhi; LI Hong-zhou
    Computer Engineering. 2009, 35(21): 67-70. https://doi.org/10.3969/j.issn.1000-3428.2009.21.023
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    This paper researches and analyzes the compiling strategy of n-conditional branch statements, and offers a formal description to the typical realization strategy of n-conditional branch statements under intricacy mode. By analyzing the formats of calling instructions to the index table and the jump table, a novel recognition algorithm is proposed based on characteristic instruction matching. To eliminate the influence caused by type and edition varieties of different compilers, it establishes two standard calling expressions to the index table and the jump table, which improves the universality of the algorithm.
  • TANG Xiao-chun; HAO Ting
    Computer Engineering. 2009, 35(21): 71-73. https://doi.org/10.3969/j.issn.1000-3428.2009.21.024
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    Scientific workflow on distributed computing environment has huge data transfer and storage. Aiming at this problem, on the environment of an executing machine which have limited storage resource, this paper disassembles the tasks of workflow into data jobs and computing jobs. The model of new workflow which include data jobs and computing jobs is proposed. It inserts data clear job when those data are no longer needed and transfer jobs when data need to transfer from one executing node to others, the method of creating the new workflow is provided. Schedule algorithm for scientific workflow based on the consider of available storage is proposed. Experimental results indicate that the schedule algorithm consumes less response time and raises the efficiency.
  • XU Xiu-lin; HU Ke-jin
    Computer Engineering. 2009, 35(21): 74-77. https://doi.org/10.3969/j.issn.1000-3428.2009.21.025
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    When Jha makes research on the survivability of information system with the method of model checking, it lacks the research on the relation between the different attacking scenes and failed system nodes, and it does not consider how to measure the survivability when the system provides multi-services at the same time. Aiming at such problems, this paper proposes an improved algorithm of measuring the survivability of information system based on Model Checking(MC), and constructs the survivability model of the system supplying multi-services at the same time facing different test scenes. It is proved that the new method is suit for survivability analysis.
  • MO Xi; ZHAO Fang
    Computer Engineering. 2009, 35(21): 78-81. https://doi.org/10.3969/j.issn.1000-3428.2009.21.026
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    Aiming at the problems in Graphical User Interface(GUI) program automation test, this paper designs and implements a reusable data- model-driven software automation test framework which is based on RFT tool and supports distributed multi-platform network environment. The framework separates test object, test case data, test case logic and execution control reasonably. The implementation of the framework can enhance the reusability, reduce the maintenance costs, increase the execution automation degree of the test cases and improve the software regression test process.
  • ZHANG Feng-gui; CHENG Liang-lun
    Computer Engineering. 2009, 35(21): 82-84. https://doi.org/10.3969/j.issn.1000-3428.2009.21.027
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    The characteristics of query data for RFID middleware are analyzed. Based on the characteristics, a method named aggregate transformation is proposed to save storage cost of index and reduce insertion time. The performance of several existing multidimensional indexes is analyzed and compared, KDB-tree index is supplied into RFID middleware. Theoretic analysis and experimental results demonstrate that KDB-tree index outperforms others in synthesized consideration of storage cost, insertion time cost and query time cost. In particular the query time cost of KDB-tree is distinctly lower than others because it provides single-path traverse in the query processing.
  • WANG Chang-wu; HAN Jing-hua; ZHANG Fu-zhi
    Computer Engineering. 2009, 35(21): 85-87. https://doi.org/10.3969/j.issn.1000-3428.2009.21.028
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    Metadata records duplicate detection and management of federated digital library are one of key issues to ensure metadata quality and improve federal retrieval services. Many duplicate record detection methods exist for conventional federated digital library, but they are computationally intensive and low accuracy and so on. This paper proposes an efficient duplication approach for a relatively large federated digital library based on improved N-Gram method. Simulation experimental results show that the method improve the performance of duplicate detection effectively, accelerate the rate of duplicate detection.
  • QIU Jing
    Computer Engineering. 2009, 35(21): 88-90. https://doi.org/10.3969/j.issn.1000-3428.2009.21.029
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    This paper analyzes the structural feature of common functions after decompiling, proposes function identification technology based on basic block partition, and applies it in the design of fast library function identification. It provides the solution for the problems in library function identification such as relocation and cascade identification. Realization method on how to build and read the function feature database and library identification algorithm is represented. Experimental results prove that the technology can identify library functions precisely.
  • Networks and Communications
  • MA Yong-guang; CHEN Wen-ying; WANG Bing-shu; CHEN Xiao-wei
    Computer Engineering. 2009, 35(21): 91-93. https://doi.org/10.3969/j.issn.1000-3428.2009.21.030
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    This paper proposes a schedule method based on network-induced error is designed to solve collision of communication in network control systems. Traditional static and dynamic schedule policy is analyzed, criterion to satisfy network resource scheduling is given, some restrictions to get good stable performance is brought out. For under schedule, by monitoring network-induced error, to change sensor’ sample periods and to remedy sample data in controller. Simulation validates the effectiveness of the proposed schedule method.
  • WU Zhi-gang; BAI Guang-wei; WU Yan-jie
    Computer Engineering. 2009, 35(21): 94-96,1. https://doi.org/10.3969/j.issn.1000-3428.2009.21.031
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    Aiming at the problem that wireless Ad Hoc networks can not provide any priority scheme, this paper proposes a proved mechanism based on 802.11DCF back-off algorithm. The new mechanism, by reducing the retransmission number of high-priority data flows at the data link layer, can make high-priority data flow(such as Real-time data flow) access channel more easily, the high-priority data flow can obtain more bandwidth, and the average end-to-end delay is reduced as well. Analysis results show that the new algorithm can improve the transmission performance of data flows in high priority significantly.
  • PENG Ai; HUANG Lan; WANG Zhong-yi; WANG Cheng
    Computer Engineering. 2009, 35(21): 97-100. https://doi.org/10.3969/j.issn.1000-3428.2009.21.032
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    Aiming at the problem of limited energy of Wireless Sensor Networks(WSN), this paper proposes an approach of energy-saving improving for LEACH protocol in aspect of stability. Using a simulation software NS-2 simulation, this paper compares performances of the improved version of LEACH protocol with the original one and discussed the influence of the energy dissipation of sensing module on the protocol improvement. Simulation results show that the modified protocol improves 45.87% longer lifetime and 35.16% more data than the original one as well as the value of CV. But it is found that when the energy dissipation of sensing module is more than 60% of the total energy, the improvement of the protocol is invalid.
  • ZHU Fang-dong; WANG Jun-feng
    Computer Engineering. 2009, 35(21): 101-103,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.033
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    This paper summarizes the three-layer modeling mechanism of those widely used tools, and points out the disadvantages of this mechanism in complex network condition. To deal with these shortcomings, an extended three-layer modeling mechanism is proposed. According to this mechanism, Aeronautical Telecommunication Network(ATN), a rather complex network, is modeled by OPNET. By analyzing the quality of services and calculate the degree of reliability based on the network measurement, it is proved that this mechanism can model the complex network efficiently.
  • LI Ke-qing; CUI Yan-rong
    Computer Engineering. 2009, 35(21): 104-107. https://doi.org/10.3969/j.issn.1000-3428.2009.21.034
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    This paper analyzes stochastic deployment of sensor nodes, puts forward a new Node Coverage and Round-robin Schedule(NCRS) algorithm based on nodes track. Working role of node is negotiated according to the built location information of monitoring objects, each monitoring sensor node constructs an independent routing path to sink nodes, which including those not yet unused relaying nodes, thus all of monitoring objects will be covered by different monitoring sensor nodes more than one times. Simulation experimental results indicate that NCRS can not only improve the coverage degree of monitoring objects effectively, but also increase the proportion of working nodes, and prolong the life time of sensor networks.
  • KONG Jun; JI Hai-bo
    Computer Engineering. 2009, 35(21): 108-110. https://doi.org/10.3969/j.issn.1000-3428.2009.21.035
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    Aiming at the lack of accuracy in the traditional localization method of least-square, the DFP algorithm is adopted in this paper to solve the Wireless Sensor Networks(WSN) localization problem. The algorithm avoids the calculation of a second derivative matrix and its inverse, especially for high-dimensional problems and achieves the optimization result of nodes localization. Simulation experimental result shows the algorithm can effectively increase the node positioning accuracy.
  • WEI Ya-qing; LI Jie; ZHENG Ding
    Computer Engineering. 2009, 35(21): 111-113. https://doi.org/10.3969/j.issn.1000-3428.2009.21.036
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    Nodes in Ad Hoc network move without rule, so the problems of routing protocol and QoS guarantee face new difficulties. Architecture of grade is applied widely in Ad Hoc networks to reduce the route cost, and satisfies the request of network extending. A clustering algorithm based on transmission power is given. Comparing the performance of the algorithm with three other clustering algorithms in terms of reaffiliation frequency and dominant set update, it is proved validity in respect of cluster architecture stability through simulation experiments.
  • CHEN Hong-liang; LI Jie; WANG Tao
    Computer Engineering. 2009, 35(21): 114-116. https://doi.org/10.3969/j.issn.1000-3428.2009.21.037
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    (College of Information Science and Engineering, Central South University, Changsha 410075)
  • LV Lin-tao; FAN Yong-lin
    Computer Engineering. 2009, 35(21): 117-119. https://doi.org/10.3969/j.issn.1000-3428.2009.21.038
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    Aiming at the problem of unbalanced energy consumption in the existing Wireless Sensor Networks(WSN) uneven clustering routing algorithm, this paper proposes an energy-balanced uneven clustering WSN routing algorithm. It constructs a middle layer in the divided non-uniform zone to achieve the energy consumption balance of cluster head and inter-cluster node, which realizes the overall energy consumption balance of WSN. Experimental results show that the algorithm can balance the WSN energy consumption, improve the WSN energy efficiency and extend 100~200 rounds of WSN life cycle.
  • Security Technology
  • YANG Rui-jun; CHENG Yan; WANG Wei-nong
    Computer Engineering. 2009, 35(21): 120-122. https://doi.org/10.3969/j.issn.1000-3428.2009.21.039
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    Mobile Ad hoc network is a crossbred of computer network and wireless communication. A new Intrusion Detection System(IDS) scheme based on allocated tasks of IDS functions is proposed, and the main functional modules implementation is provided. Experimental result shows that new IDS scheme not only satisfies the basic requirements same as the traditional IDS, but also saves the network resources effectively with enhancing the availability of mobile nodes in Ad hoc networks.
  • GAO Zhi-hui; XIAO Jun; WANG Ying; YAO Zhi-qiang
    Computer Engineering. 2009, 35(21): 123-124,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.040
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    By using side information in frame and between frames, this paper proposes a video watermark algorithm in wavelet domain with side information. In the algorithm, dither modulation is adopted, and the motion feature and texture feature are used as side information to determine the adaptive quantification step of every frame. Experimental results indicate that the algorithm can implement blinding examination and the invisibility is good. It is also robust to the special attacks of video watermark such as Gaussian noise, frame average, frame delete and frame displacement.
  • CHEN Hu; SONG Ru-shun
    Computer Engineering. 2009, 35(21): 125-127,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.041
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    This paper studies ring signature in the newly proposed certificatelss public key setting. Due to the practical application of the ring signature, using bilinear maps, it constructs a certificateless ring signature scheme. It is proved secure in the strong security model. In the certain anonymous universal set, it just needs one pairing operation in its signing and verification phases. The analysis shows that the scheme satisfies all the security requirements. The security of the scheme is based on the fact that computational Diffie-Hellman problem is hard. It may have practical application in electronic election and electronic auction, etc.
  • CHEN Meng
    Computer Engineering. 2009, 35(21): 128-130. https://doi.org/10.3969/j.issn.1000-3428.2009.21.042
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    By amending System Service Dispatch Table(SSDT), the malicious code can avoid being cleared by antivirus software or anti-malice software. Aiming at SDDT hook technology, this paper realizes an anti-malicious code technology based on SSDT restoration through system file relocation. It expatiates the method of resetting Ntoskrnl.exe files and the method of shifting comparison of Ntoskrnl.exe files. Experimental results show that this technology can invalidate malicious codes and Trojan programs and guarantee system security.
  • LIU Jun; JIN Cong; DENG Qing-hua
    Computer Engineering. 2009, 35(21): 131-133,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.043
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    An E-mail virus spreading model based on the scale-free network is proposed. By mathematical calculations, the density of infected users is obtained, and it is affected by many parameters, e.g., spreading rate, recovery rate and average degree of network, etc. Experiments show that the density of infected users finally becomes a stable state before anti-virus technique appearing. Moreover, the spreading rate and average of degree of network take the key important role in this phase.
  • CHEN Fan; GU Da-wu; ZHANG Yuan-yuan
    Computer Engineering. 2009, 35(21): 134-137. https://doi.org/10.3969/j.issn.1000-3428.2009.21.044
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    In the field of security research of Wireless Sensor Networks(WSN), there exists three main kinds of key predistribution schemes, which are the basic key predistribution, the q-composite key predistribution scheme, both for homogeneous sensor networks, and the key predistribution scheme for heterogeneous sensor networks. By analyzing the security of all these key predistribution schemes, a more accurate threat model is established, and a flexible method for security quantitative analysis is presented. Statistical analysis and simulation experiments show that the method can evaluate in quantity the security of different key predistribution schemes.
  • BAI Yu; TENG Jian-fu; ZHANG Li-yi; GUO Ji-chang
    Computer Engineering. 2009, 35(21): 138-139,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.045
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    The Radio Frequency Identification(RFID) authentication protocol based on Hash lock and key updating may lead to desynchronization which makes the tag-to-reader authentication fall into failure. In the paper, the anti-desynchronization methods of several RFID authentication protocols are analyzed and the disadvantages of which are also pointed out, and a novel scheme, Hash lock-based strengthen synchronization RFID authentication protocol is proposed. The scheme achieves the anti-desynchronization requirement by adding anti-desynchronization Key Kp into the database. Analysis result shows that the new scheme realizes the requirement of anti-information leakage, intraceability and synchronization with a low computing load.
  • JIANG Chang-yong; ZHANG Jian-ming; WANG Liang-min
    Computer Engineering. 2009, 35(21): 140-143. https://doi.org/10.3969/j.issn.1000-3428.2009.21.046
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    According to the drawbacks that methods of attack detection in wireless sensor networks require cooperation of nodes or hardware, selective forwarding attack is studied and a light-weight method based on trust degree and behavior of packet loss is proposed. The method detects the attack by calculating trust degree and evaluating behavior of packet loss of nodes, which are based on statistics of receiving and forwarding packets. The calculating and storage pressure of the method are concentrated on the base station and the method works without auxiliary equipment. Experimental results show that the method has relatively higher detection rate than existing methods.
  • WANG Lei; ZHANG Yu-qing
    Computer Engineering. 2009, 35(21): 144-146,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.047
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The growing mobile phone viruses brings great threat to the users. In this paper, an anti-virus software named WMAV on the Windows Mobile(WM) platform is presented. A fast, accurate virus scan engine in this software is designed and implemented, and the file system filter is used to achieve a real-time monitoring and virus scanning under the storage management of the file system.
  • ZHAO Bin-bin; ZHANG Yu-qing; LIU Yu
    Computer Engineering. 2009, 35(21): 147-150. https://doi.org/10.3969/j.issn.1000-3428.2009.21.048
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper presents a method of detecting Instant Messaging(IM) worm on the base of its propagation characteristics. It monitors all the IM messages at the gateway and detects worm through statistical growth of suspicious messages. It adopts dynamical queues to reduce the storage and implements a user confirmation module to verify suspicious messages which improves the detection accuracy. Experiments show that on the basis of assuring the detection accuracy, it can effectively reduce the burden of the server, save the memory resources and reduce the impact on normal communication.
  • SHEN Shou-zhong; ZHANG Yu-qing
    Computer Engineering. 2009, 35(21): 151-154. https://doi.org/10.3969/j.issn.1000-3428.2009.21.049
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Through the deep study and analysis of the Cross Site Scripting(XSS) vulnerability, this paper knows that how the XSS vulnerability produces and to be used. Further analysis and improvement are made about the XSS vulnerability’s detection mechanism. This paper realizes an XSS vulnerability detection tools(XSS-Scan) based on Crawler’s technology, and does the analysis and comparison with some popular softwares. This tool can be used to audit the Web site’s safety and detect the existence of XSS vulnerability in it.
  • CAI Ji-wen; YI Ping; ZHOU Yong-kai; TIAN Ye; LIU Ning
    Computer Engineering. 2009, 35(21): 155-158. https://doi.org/10.3969/j.issn.1000-3428.2009.21.050
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper compares several attack models aiming at mobile Ad Hoc network’s prosperity of routing vulnerable, and presents a classification that divides black hole attacks into two specific types, such as passive black hole attacks and active black hole attacks under Dynamic Source Routing(DSR) protocol. It implements three attack patterns, including the RREQ flooding attacks, the passive black hole attacks and the active black hole attacks, on DSR protocol using the Network Simulator 2(NS2). It demonstrates different performances of the network under these attacks and compares their fatality, so as to draw the conclusion that RREQ flooding attack is more harmful than the two kinds of black holes, and additionally, among black hole attacks, an active one is more dangerous.
  • LUO Xiao-gang; LI Xuan; PENG Cheng-lin; HOU Chang-jun; HUO Dan-qun
    Computer Engineering. 2009, 35(21): 159-161. https://doi.org/10.3969/j.issn.1000-3428.2009.21.051
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    According to the storage characteristics of digital image, an image encryption algorithm based on extended two-dimensional Cellular Automata(CA) is proposed in this paper. It combines the two-dimensional CA with the technology of image encryption, which uses CA to generate a two-dimensional matrix pseudo-random number ranged from 0 to 255 automatically and takes a part of this matrix as the code to encrypt image pixels, and the size of this matrix is the same as the image. The decryption is the converse process of encryption. Experimental results demonstrate this algorithm can generate cryptogram rapidly and has a simple encrypt form as well as a better performance against attacks. It is suitable for encrypting digital images with huge data.
  • ZHOU Hai-yan
    Computer Engineering. 2009, 35(21): 162-163,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.052
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the certificate revocation problems in Public Key Infrastructure(PKI), a Certificate Revocation B_Tree(CRBT) scheme is proposed, which keeps maximal time complexity as O(logd((n+1)/2)+1) in query and update process. Compared with other schemes, it shows more superiority when the data volume is extreme huge. The certificate management scheme based on B_tree is introduced. Experimental results show this scheme is significant to engineering implementation.
  • LIU Mei
    Computer Engineering. 2009, 35(21): 164-166. https://doi.org/10.3969/j.issn.1000-3428.2009.21.053
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Existing self-adaptive image encryption algorithm is resistant to known plaintext attacks and with high speed of single round encryption, but its security and speed of whole round encryption is low. This paper proposes a new fast image encryption algorithm based on self-adaptive permutation. This algorithm insures the simpleness and high efficiency of encryption operation, and changes the pixel distribution of encrypted image compared with that of original image. Experimental results show that this algorithm has better performance than other kindred algorithms.
  • ZHANG Jiu-hua; LI Min; HE Guang-pu; ZHANG Jian-ping
    Computer Engineering. 2009, 35(21): 167-168. https://doi.org/10.3969/j.issn.1000-3428.2009.21.054
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    According to the similarity constant character of image maximum DCT normalization coefficient, an image digital watermark algorithm based on spread spectrum coding is proposed, which uses spread spectrum strategy to insert larger quantity of watermark into original images. It has better robustness to printing scanning attacks. Simulation experimental results show this algorithm can avoid both pixel distortion and geometry distortion at the same time produced in process of printing and scanning, and fit for applications of electronic seal and paperwork digital watermark anti-counterfeiting.
  • LV Lin-tao; WANG Wei
    Computer Engineering. 2009, 35(21): 169-170,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.055
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the weak robust to the geometric attacks of the public-key watermark algorithm, a public-key watermark algorithm based on Scale Invariant Feature Transform(SIFT) is proposed for resisting Rotation Scale Translation(RST) attack in this paper. The feature keypoints of original image are extracted. The watermark in the DCT domain of the feature zone is embedded, so that it can resist the RST attack better, and the verification of the watermark is public. Experimental results demonstrate this algorithm can resist general RST attacks and signal processing attacks.
  • MA Xin-qiang; HUANG Yi; LI Dan-ning
    Computer Engineering. 2009, 35(21): 171-173. https://doi.org/10.3969/j.issn.1000-3428.2009.21.056
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to give attention to BLP model and Biba model in process of implementing multi-level security system, the lattice theory shaped in math of security model sensitivity labels sets is analyzed. A security theoretical model of sensitivity labels lattice is proposed, which can fuse these two models. The information confidentiality and integrity are labeled. By setting up new sensitivity labels lattice theoretical models, the theory basis is provided to information security research.
  • MI Jun-li; ZHANG Jian-zhong
    Computer Engineering. 2009, 35(21): 174-175. https://doi.org/10.3969/j.issn.1000-3428.2009.21.057
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    This paper presents a threshold-signature with proxy signers, in which some signers can delegate their proxies to do the signatures. The scheme can recall the proxy signature right of the proxy signer delegated by the original signer if the original signer needs. Signature generation needs an interactive protocol among participants without the trusted dealer. This scheme is secure and efficient, and it has smaller key and is easy to realize. Security analysis proves it is secure and effective.
  • ZHU Ying-hong; ZHAO Huai-xun; SU Guang-wei
    Computer Engineering. 2009, 35(21): 176-177,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.058
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the problem that the public key and key trustee must be proved by certificate in electronic cash schemes, this paper proposes a certificateless off line electronic cash scheme. It uses the bilinear pairing to structure the frame of certificateless authentication in electronic cash, solves the problem of users’ key trustee and improves the security of electronic cash. This scheme reduces the processes of identity authentication and increases the rate and efficiency of the trade. It constructs a simple and effective key exchange method. Analysis results of security and feasibility show that the scheme is reliable.
  • Artificial Intelligence and Recognition Technology
  • WANG Zhi-wen; LIU Mei-zhen; CAI Qi-xian; XIE Guo-qing
    Computer Engineering. 2009, 35(21): 178-180. https://doi.org/10.3969/j.issn.1000-3428.2009.21.059
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    There is data redundancy temporal database and the quantities of temporal database are increasing fleetly, aiming at these problems, this paper puts forward compressed storage tactics based on improved genetic algorithm for temporal data which combine compress technology in existence in order to settle data redundancy in the course of temporal data storage. Temporal relation data at any moment is decomposed into least granularity data and be coded meanwhile. Optimized storage data are figured out by using improved genetic algorithm, and the ratio of compression is enhanced. Celerity astringency of the algorithm can heighten speed of removing data redundancy largely.
  • XUE Jun; CHENG Jun; WANG Li; GAO Xiao-rong; JIANG Jun;
    Computer Engineering. 2009, 35(21): 181-182,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.060
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Traditional template matching methods are not proper for the rotation situation of component logo in the industrial production detection. Aiming at this problem, this paper proposes a rotation invariance detection scheme based on circular projection and vector sum. Through making mask of which coefficient is multiplied by the corresponding pixel, this method realizes function of circular projection statistics of grayscale image and 1D eigenvector vector circularity summing. Experimental results demonstrate that this method can realize symbol matching after the target is rotated and has higher noise suppression ability and detection speed than SIFT algorithm.
  • XU Jin-bao; YE Qiao-lin; YE Ning
    Computer Engineering. 2009, 35(21): 183-185. https://doi.org/10.3969/j.issn.1000-3428.2009.21.061
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    Aiming at the flaw of singular problems appearing in GEPSVM, this paper proposes an improved GEPSVM——SMGEPSVM. Two non-parallel surfaces are obtained by solving simple Eigen-values problems. Compared with GEPSVM, the approach can solve XOR problems, and it further solves the simple Eigen-value problems, avoids the singular problems appearing in GEPSVM, it has better test set correctness and faster training time. Computational results on artificial datasets and UCI indicate the better performance of SMGEPSVM.
  • LI Shao-fang; HU Shan-li
    Computer Engineering. 2009, 35(21): 186-188,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.062
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    During the generating process of coalition structure, two coalitions with same cardinality always have same value or similitude value. It is necessary to search the lowest two levels of the cardinality structure graph while establishing a bound of different coalition with same cardinality and same value. This paper researches the problem about best cardinality structure generating, proposes an algorithm for cardinality structure generating with bound and ascertains cardinality structures need to be further searched. Analysis results show that the required bound can be achieved by searching the cardinality structure set after searching the lowest two levels and the top level of the cardinality structure graph. The number of cardinality structures for searching of this algorithm is minimal comparing with other algorithms for cardinality structure generating.
  • LU Yuan
    Computer Engineering. 2009, 35(21): 189-191. https://doi.org/10.3969/j.issn.1000-3428.2009.21.063
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a gait recognition approach based on Fuzzy Support Vector Machine(FSVM). By using the width vector as feature, it discusses the influence of assign value algorithm and fuzzy C-means algorithm on the recognition rate of gait recognition. Experimental results show that compared with Support Vector Machine(SVM), fuzzy C-means algorithm improves the effectiveness of the classification with FSVM, but the recognition rate of the assign value algorithm is lower than with SVM, which indicates that choosing an appropriate fuzzy membership is the key for FSVM to be applied in gait recognition successfully.
  • ZHAO Da-ming; YU Bin
    Computer Engineering. 2009, 35(21): 192-194. https://doi.org/10.3969/j.issn.1000-3428.2009.21.064
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The query result returned by meta-search engine is from the independent search engine. To evaluate the professional relevance of these results, it must exploit more information than the location information. This paper studies and realizes a training field oriented meta-search engine. It fully mines the file information of Web page, extracts swatch characteristics of professional Web page and gives professional relevance degree algorithm for Web page. Experimental results show that this engine has high ability of professional information filtration and taxis.
  • WANG Zhi-jie; QUAN Hui-yun
    Computer Engineering. 2009, 35(21): 195-196,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.065
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    Aiming at the problems of slow converge-rate and precocity when using Ant System(AS) algorithm to solve Degree-Constrained Minimum Spanning Tree(DCMST) problem, this paper presents an improved algorithm named UDA-ACS(Unequal initial pheromone strategy, Dynamic negative feedback mechanism, Adequately augment the effect of visibility-Ant Colony System). It retains the advantages of Ant Colony System(ACS) algorithm, and adopts the method of augmenting the effect of visibility, dynamic negative feedback mechanism and giving with unequal initial pheromone. Theory analysis and experimental result prove that it gains better solving quality and higher speed than AS algorithm.
  • PAN Wei; SHEN Chao
    Computer Engineering. 2009, 35(21): 197-199. https://doi.org/10.3969/j.issn.1000-3428.2009.21.066
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    The development of Internet gives birth to many unconventional datasets like hierarchical classification labels. Current Part Of Speech(POS) tagging tools fail on these datasets. To solve this problem, this paper proposes a simple method using Max Entropy Model(MEM) framework, which introduces a new tag and two new features extracted from Wordnet and Wikipedia, and comes up with a significant improvement. Experimental results show that the precision reaches 93.77% on DMoz.
  • Graph and Image Processing
  • WANG An-na; YANG Ming-ru; LIU Zuo-qian; WANG Ting-jun
    Computer Engineering. 2009, 35(21): 200-202,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.067
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A medical image fusion method based on the wavelet transformation and Self-Organization feature Map(SOM) neural network is proposed in this paper. Wavelet transformation of image is done. The wavelet coefficients are used as the characteristics. The SOM network is used to realize the cluster of images and the fuzzy classification is done. The image pixels fusion weights are determined according to the classified result. The fusion image is obtained. Simulation experimental results show this method can get better performance.
  • WU Shen-zhi
    Computer Engineering. 2009, 35(21): 203-205. https://doi.org/10.3969/j.issn.1000-3428.2009.21.068
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    The existed algorithms can not distinguish boundary surfaces with low gradient values from cracks resulted from noises for boundary surfaces with gradient values changing from high to low within 3D images. In order to settle this problem, this paper proposes a semi-transparent visualization method. It exploits intelligence and knowledge of human beings to effectively separate boundary surfaces with low gradient values from cracks resulted from noises by visualizing them translucently. It is proved that the boundary surfaces with gradient values changing from high to low within 3D images can be visualized completely and understood correctly.
  • SHI Jing; PENG Jin-ye; WANG Da-kai; ZHANG Huan
    Computer Engineering. 2009, 35(21): 206-207,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.069
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    This paper analyzes the shortage of the current Canny edge detection algorithm which only uses the Gradient Module(GM) to characterize edges and proposes an improved algorithm based on Curvature-Weighted Gradient Module(CWGM), which meets the special need of edge extraction for image coding compression. Experimental results show that the improved Canny edge detection algorithm can compress the stray edges which are non-significant to object representation more effectively, and its performance is better than the current Canny algorithm.
  • GUAN Yan; LIAN Qiu-sheng
    Computer Engineering. 2009, 35(21): 208-210. https://doi.org/10.3969/j.issn.1000-3428.2009.21.070
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    A major drawback of Block Discrete Cosine Transform(BDCT) is that the decoded images, especially at very low bit rates, exhibit highly noticeable blocking artifacts near the block boundaries. This paper proposes the method for combining weighted-Total Variation(w-TV) with complex wavelet threshold. By using the properties of w-TV with complex wavelet threshold, experiment shows that this method can reduce blocking artifacts and keep much more characteristic structures of image, it has the favorable vision effect.
  • HAO Rui; PENG Jin-ye; WANG Da-kai
    Computer Engineering. 2009, 35(21): 211-212,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.071
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The images magnified by traditional interpolation method have shortages such as blurred edges and jagged edges. Aiming at this problem and based on the analysis of the Total Variation(TV) model used in image restoration, this paper adopts Chromaticity-Brightness TV restoration model to color image magnification and transforms image magnification problem into image mending. Experimental results show that the method can keep the lubricity and definition of magnified image edges.
  • ZOU Rong
    Computer Engineering. 2009, 35(21): 213-215. https://doi.org/10.3969/j.issn.1000-3428.2009.21.072
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    In order to remove the effect of weather in degraded image, this paper proposes an improved image defogging algorithm by minimum distortion. Imporoved algorithm divides up the area of sky automatically and gets the optimal estimate of original signal based on minimum distortion rule in information theory, and acquires the dichromatic atmosphere scattering model of all the required parameters automatically. It realizes a fog degraded image de-fogged successfully. Simulation results in the Matlab platform demonstrate that improved algorithm has good real-time and self-adaptability.
  • Multimedia Technology and Application
  • ZHAO Hai-jun; CUI Meng-tian; LI Ming-dong
    Computer Engineering. 2009, 35(21): 216-218. https://doi.org/10.3969/j.issn.1000-3428.2009.21.073
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    A motion estimation algorithm for block-based MPEG is given by analyzing video traffic transmission performance and modeling in ATM networks and modeling method of high degrees of motion video source, namely, full motion, and a non-linearity model is introduced. and used to AR-based quadratic modeling for MPEG video traffic at GOP layer. Simulation shows that NAR model can provide accurate prediction to real MPEG flow with moderate motion and acceptable prediction to traffic with high motion at various load and buffer sizes.
  • LIU Guo-fan; CAO Shao-kun; PENG Tie-gang
    Computer Engineering. 2009, 35(21): 219-221. https://doi.org/10.3969/j.issn.1000-3428.2009.21.074
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Motion estimation of time-consuming brings great difficulties to real-time video encoding. In order to improve monitoring of real-time video encoding, a rapid motion estimation algorithm for embedded video monitoring system is proposed. Based on the characteristics of a relatively fixed monitoring background, the algorithm uses multi-criteria of early stop, predicts search starting point through vector movement relatively characteristics of time and space, finally, uses improved rood search pattern starting search. Experiment shows that the algorithm has better search rate than adaptive rood search algorithm with slight PSNR decrease, matches the real-time priority principle in embedded video monitoring system.
  • ZHOU Zhi-li; GUO Shu-qin; RUAN Xiu-kai
    Computer Engineering. 2009, 35(21): 222-224,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.075
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the shortcoming which the computation of target bits and Quantization Parameters(QP) in the situations of high motions and scene change of the existing H.264 rate control, this paper proposes a method of frame-level target bits allocation which based on the frame complexity to improve the above-mentioned two aspects. Due to the characteristic of moving image, which the differences in difference image is obvious, it uses frame complexity to re-allocation the target bits, at the same time, uses the frame complexity to detecting scene change to adjust the quantization parameters. Experimental results show that the improved algorithm can make target bits more closer to the actual bits, increase peak signal to noise ratio, decrease fluctuation of peak signal to noise ratio.
  • WU Wei-gang; CHI Xue-fen; LI Hong-xia; JI Feng-lei
    Computer Engineering. 2009, 35(21): 225-227. https://doi.org/10.3969/j.issn.1000-3428.2009.21.076
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    Aiming at the problem that aliasing noise will be introduced when alleviating network congestion by software down-sampling in IP video communication, a spatial processing method of aliasing noise is proposed. It uses mask operator to preprocess image before down-sampling. The system test indicates that this method can effectively reduce the aliasing noise of the low resolution video image. The method is simple, easy to realize and real-time. It guarantees the smoothness and robustness of the video when the network is in congestion.
  • ZHU Bing-lian; LIU Jian-dong
    Computer Engineering. 2009, 35(21): 228-230,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.077
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    Aiming at the problem that the compressed video stream will inevitable be corrupted because of the wireless channel errors, which may degrade the reconstructed image quality, this paper presents an efficient temporal error concealment method which based on improved border-matching function and flexible macroblock mode of H.264 video standard. It utilizes the relativity between lost macroblock and other surrounding macroblocks to predict the block mode, and estimates the motion vector of the lost macroblock depending on the block mode. Simulation results under 3GPP/3GPP2 wireless channel show the proposed method performs better quality than other approaches with the same RTP packet loss rate.
  • Engineer Application Technology and Realization
  • HU Xiao-long; LI Lie-wen; ZHOU Jun-ming
    Computer Engineering. 2009, 35(21): 231-234. https://doi.org/10.3969/j.issn.1000-3428.2009.21.078
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    A design scheme of aircraft cockpit display system based on System on Programmable Chip(SOPC) and graphics accelerating engine is put forward. In order to avoid the memory bottleneck caused by the fragmentary operations of graphics accelerating engine to frame buffer directly, a graphics cache mechanism is introduced in the graphics accelerating engine. According to the pixel graphics storage characteristics, it proposes a “Farthest Area First(FAF)” buffering replacement algorithms. A hardware/software co-design scheme is introduced for Chinese characters and bitmap display by hardware lock mechanism. A visual verification method for system-level simulation is proposed based on logic wave form simulation.
  • DU Yu-chuan; ZHOU Xiao-peng; YUAN Wen-ping; SUN Li-jun
    Computer Engineering. 2009, 35(21): 235-237,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.079
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on requirement analysis of traffic management for urban expressway network in Shanghai, this paper discusses a layered model of system structure to suit for the second-order traffic network management strategy, which is called “independent control in subarea, coordinative management in whole network”. Considering the characters of traffic flow, the principles for allocation of traffic subarea, arrangement of traffic detect devices and setup of multilevel traffic information guidance signs are provided for system design and implementation of traffic network dynamic guidance. The before-after analysis shows that the application of traveler information system in Shanghai urban expressway improves the network service level by 15%.
  • TIAN Shi-yong; WU Li-hui; SUN Lei; ZHANG Jie
    Computer Engineering. 2009, 35(21): 238-241. https://doi.org/10.3969/j.issn.1000-3428.2009.21.080
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    With high automation level, PCB assembly industry is circumscribed by the product marking while it intends to improve its production tracking. To change this, this paper uses Radio Frequency Identification(RFID) to mark the materials and the products instead of barcode as before. It defines the functions of RFID middleware, defines the information exchange between the function modules and develops the middleware. All this make product tracking system more efficient.
  • XIA Yuan-you; LU Qing; LIU Ling-wei
    Computer Engineering. 2009, 35(21): 242-243,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.081
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    Based on the technology requirements of geological survey of geological hazard control engineering for the third period of Three Gorges reservoir area, this paper designs landslide stability system of Three Gorges reservoir area with the technology of GIS, to support quantitative evaluation of stability for alarm conducting system. It elaborates the construction target and details of the landslide stability evaluation system of Three Gorges reservoir area based on GIS, places great emphasis on analyzing the global design, logical structure and functional module design of the system, and shows the implementing interface of the system.
  • QIAN Zhi-hao; WANG Jian-zhong
    Computer Engineering. 2009, 35(21): 244-246. https://doi.org/10.3969/j.issn.1000-3428.2009.21.082
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    In order to monitor and control equipments of the urban sewage pumping station real-time and remotely, this paper analyzes the features and realization method of SNMP protocol and OLE for Process Control(OPC) technology, and constructs an extended manager/Agent system by combining the two technologies, adopting AgentX protocol and embedding OPC client into SNMP Agent. It verifies this method feasibly by examples and this new system can enhance the safe operation of equipment and improve the operating efficiency of the pumping station.
  • Developmental Research
  • WANG Fei; WU Qing-bo; YANG Sha-zhou
    Computer Engineering. 2009, 35(21): 247-249. https://doi.org/10.3969/j.issn.1000-3428.2009.21.083
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    Web page ranking technology is one of the core technologies of search engine. This paper describes the necessity of Web2.0 community to build semantic search, analyzes the factors impacting the page ranking, and implements the ranking algorithm of search engine to the search module technology which is based on Web2.0 community. Based on the improved algorithm of TF/IDF and PageRank, a search module is worked out which is based on semantic ranking on a developing platform of Web2.0 open source community. Experimental results show that the ranking algorithm is featured as exactly finding the wanted contents, and ranking the efficient results on top.
  • PU Xue-feng; ZHU Wei-xing; LU Chen-fang
    Computer Engineering. 2009, 35(21): 250-252. https://doi.org/10.3969/j.issn.1000-3428.2009.21.084
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    This paper designs an automatic detection system aiming at the disadvantage that traditional manpower observation method can not find pigs sick in time. The system monitors the pigs excretion behavior by 24 h based on advanced RISC Microprocessor platform. It orients suspected sick abnormal pigs by using an improved moving object detection algorithm and image recognization algorithm based on symmetrical characteristic of pixel block, the alarming image is send to the monitor center through GPRS. Experimental results show that the system has well real-time and monitor effect, and its commonality is good.
  • LI Hua; ZHANG Ju-ping; YE Xin-ming; WU Cheng-yong
    Computer Engineering. 2009, 35(21): 253-255. https://doi.org/10.3969/j.issn.1000-3428.2009.21.085
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    During the processing of implementation of TTCN-3 test system, there are requirements to divide the test system into protocol related part and System Under Test(SUT) unrelated part. This paper analyzes Coder/Decoder(CD) and Test Runtime Interface(TRI) functions of protocol related part. The implementation approach is discussed. As an example, DHCPv6 related algorithms are given. And the working process of the test system is interpreted by the collaboration diagram of TTCN-3 test system component.
  • WU Shan-ming; SHEN Jian-jing; HAN Qiang
    Computer Engineering. 2009, 35(21): 256-257,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.086
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    Aiming at the ubiquitous problem of semantic heterogeneity in the description of Web service, this paper proposes a Web service composition method based on domain ontology and OWL-S. It takes the ontology concept to annotate Web service at semantic, and achieves semantic Web service composition through customizing composition process on the basis of OWL-S. The example uses protégé and OWL-S Editor tools, result proves that domain ontology and OWL-S can realize to complement each other’s advantages.
  • ZHANG Fu-zhi; ZHANG Qi-feng
    Computer Engineering. 2009, 35(21): 258-260,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.087
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    In order to improve the accuracy of forecast for new-user service, this paper proposes a collaborative filtering algorithm fusing multi-system user information. The algorithm finds neighbor and recommendation item by fusing multi-system user information to low dimensional manifold. It introduces the application process of manifold learning algorithm in recommendation service. Result shows that the proved algorithm can be more effective and accurate than traditional collaborative filtering algorithms for new user by contrastive experiment.
  • TAN Ming; CHEN Hao; SUN Jian-hua
    Computer Engineering. 2009, 35(21): 261-263. https://doi.org/10.3969/j.issn.1000-3428.2009.21.088
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    To achieve the correct lighting in Augmented Reality(AR) in time, a fast dynamic Light Map-based approach is presented. The pixel intensity of the calibration object in different video images is collected. The gain and the bias of the camera are computed. The environmental light condition is used which is recorded by the dynamic Light Map to augment the mixed scenes. If the illumination changes, new frames can update the Light Map immediately. Experimental results indicate that the approach can handle dynamic real-world illuminations and the updating speed is fast enough for real-time applications.
  • XIE Hong-wei; JI Miao-tong
    Computer Engineering. 2009, 35(21): 264-266. https://doi.org/10.3969/j.issn.1000-3428.2009.21.089
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    Based on intensive study of .NET Remoting technology and traditional distributed load balancing algorithms, this paper proposes a load-balancing algorithm of combining sequence queue and hash mapping matrix, gives a dynamic load balancing model based on distributed environment, increases system throughput, and shortens the response time of task requests. The model is modular in design, enhancing its deployment flexibility and fault-tolerant. Sliding window mechanism improves the load-balancing index’s credibility.
  • ZHANG Lei; TANG Jie; WU Gang-shan
    Computer Engineering. 2009, 35(21): 267-269. https://doi.org/10.3969/j.issn.1000-3428.2009.21.090
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    Aiming at limitations of existing PC hardware and the feature of mass seismic data, this paper presents a partitioning multilevel multi-resolution model based on extended octree. The model stores attribute of leaf nodes and intermediate nodes, realizes multi-resolution modeling, and uses data block index method based on Morton code to enhance query efficiency. Experimental results show that the model is an efficient organization style of mass seismic data, and it has well application value of the geological modeling.
  • CHEN Jie; ZHOU Song; ZHU Min
    Computer Engineering. 2009, 35(21): 270-273,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.091
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    Aiming at the problem that limited transmission bandwidth can not meet increasing communication requirements among tactical information applications, this paper proposes a tactical Information Dissemination Management(IDM) prototype system, which is based on wireless network of tactical communication application system. It gives system architecture, design of the system components, and implement process of the critical technology. Experimental result proves that the system can guarantee the pivotal information transmission efficiently and intelligently.
  • ZHANG Jun; HE Yi-gang; HOU Zhou-guo; DAI Yang
    Computer Engineering. 2009, 35(21): 274-276. https://doi.org/10.3969/j.issn.1000-3428.2009.21.092
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    This paper introduces an analysis method of phase noise requirements on a local oscillator for a UHF Radio Frequency Identification (RFID) system. In general case, phase noise requirements are derived considering a reciprocal mixing with an interference signal. In UHF RFID system, the same oscillator is used for the transmitted signal and the Local Oscillator(LO), range correlation phenomenon effects the phase noise requirements. This paper derives new phase noise equation considering the range correlation effect on the RFID system and a simulation is done. Simulation results for UHF RFID system show that range correlation effect is the important factor in RFID system design.
  • LI Yin-guo; TANG Zhuo-qun; JIANG Jian-chun; SHENG Yi-lun
    Computer Engineering. 2009, 35(21): 277-279,. https://doi.org/10.3969/j.issn.1000-3428.2009.21.093
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    This paper analyses OSEK specification applied in vehicle electronic real-time operating system and the working principle and characteristics of OIL configurator. It designs OIL configurator based on generalized table structure combining with the characteristics of AutoOSEK embedded real-time operating system, and introduces design technique and illustration of AutoOSEK embedded real-time operating system for configurator. Experimental result proves that the design can reduce repeatedly exploiting like OIL configuration system, enhance exploiting speed for different embedded operating system according OSEK specification.
  • ZHANG He-sheng; JIN Yu-hong; LI Jie; GAI Jian-ning
    Computer Engineering. 2009, 35(21): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2009.21.094
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    With the structure of aerospace craft increasingly becoming complex and its software scale being more and more inflated, the design of software framework becomes the key technology of the software design. Aiming at this problem, this paper proposes a software modularized design method based on Finite State Machine(FSM) model. It establishes event-driven mechanism and constructs system structure of the software according to the process flow which is event generating, event queue maintaining and event answering. Experimental result indicates that the design improves the reliability and developing efficiency of software, makes it easier vindicating and expanding, and reduces the disabled risk.
  • ZHANG Deng-can; LIN Chun-shen; WAN Jin; LI Xue-lai
    Computer Engineering. 2009, 35(21): 283-封三. https://doi.org/10.3969/j.issn.1000-3428.2009.21.095
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    Aiming at the disturbance of the IP channel in GPRS network, this paper proposes a packet loss resilience encoding algorithm. The algorithm makes data transmission cutted into several sections and encoded by section based on RS erasure code, uses interleaving technology to process optimal grouping and transmission for the data, and acquires approximate linear encoding and decoding time without weakening the ability of erasure correction. Simulation results show that the algorithm can better satisfy the need of real-time for mass data coding than existing RS coding style.