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20 March 2008, Volume 34 Issue 6
    

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  • LI Li-wei; MA Jian-wen; OUYANG Yun;
    Computer Engineering. 2008, 34(6): 1-2. https://doi.org/10.3969/j.issn.1000-3428.2008.06.001
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    Based on the spectral feature neighborhood, this paper proposes a tolerant rough set classification method to handle the uncertainty in the process of satellite remote sensing data classification. Experiment is carried out with Landsat-5 TM image of eastern Beijing. Classification result is compared with result from the current tolerant rough set method. Outcome indicates that the method is more interpretable and reliable, and effectively handles the uncertainty in the process of satellite remote sensing classification. It is a promising tool at classifying areas with complex spectral feature.
  • YAO Bin; LI Hai-sen; ZHOU Tian; WEI Yu-kuo
    Computer Engineering. 2008, 34(6): 3-6. https://doi.org/10.3969/j.issn.1000-3428.2008.06.002
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    k-ary n-cube( ) interconnect networks are widely used in the parallel processing system. If the numbers of nodes in some dimensions are different, generalized K-ary n-cube interconnect networks ( , )are defined using cross product of 1D ring. Calculation methods of surface and volume are proposed, and the best structure of broadcasting is determined using the surface. Formula of minimal routing path between tow nodes and the method of path selecting are ananlyzed.
  • LAN Zhang-li; YANG Xiao-fan;
    Computer Engineering. 2008, 34(6): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2008.06.003
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    This paper analyzes algorithms of gravity model, Hough transform, circle fitting, and spatial moment operators. An improved algorithm of laser spot center location is given after theoretical analysis and experiment, which can improve the location precision and anti-interference performance efficiently, and is suitable for real-time measurement. The algorithm is used in a laser deflection measurement system installed on Taipingzhang bridge and Anwen bridge of Yuqian expressway.
  • DAI Jin-you; YU Shao-hua
    Computer Engineering. 2008, 34(6): 10-12. https://doi.org/10.3969/j.issn.1000-3428.2008.06.004
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    This paper analyzes adaptive clock methods for circuit emulation service over packet switch network, describes adaptive clock methods based on jitter buffer, and proposes a fast adaptive clock method based on jitter buffer. The method is contrasted with the present congener methods. A kind of simulation device is designed and a test platform is set up to test. Experimental results show that the improved method is effective.
  • ZHAO Tao; CAI Wan-dong; LI Yong-jun
    Computer Engineering. 2008, 34(6): 13-15. https://doi.org/10.3969/j.issn.1000-3428.2008.06.005
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    This paper proposes a performance measurement method based on network tomography techniques in sensor network. It analyses the data which is transfered in sensor network received by the sink node and infers the sensor network performance characteristics. In response to the nature of sensor network, it introduces the loss model based on passive measurements and solves the loss inference problem by using MLE-EM algorithm. Simulation results demonstrate that the methodology can infer the link loss rate accurately without any additional overhead for sensor network, and scale to large sensor network.
  • FAN Hao; WU Zhe-hui
    Computer Engineering. 2008, 34(6): 16-21. https://doi.org/10.3969/j.issn.1000-3428.2008.06.006
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    Combining CPEBSDL, Petri nets reachable marking graph, and Petri net process, this paper proposes an approach named PMA_CPEBSDL that can automatically construct a Petri nets model for communication protocol, presents some methods of protocol validation and test. PMA_CPEBSDL approach and methods of protocol validation and test are introduced with a factual example about LAPD protocol.
  • WANG Shu-feng; WU Geng-feng; PAN Jian-guo
    Computer Engineering. 2008, 34(6): 22-24. https://doi.org/10.3969/j.issn.1000-3428.2008.06.007
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    Extraction Algorithm of Approximate Sequence Decision Rules (EAASDR) extracting decision rule from border region of rough set is proposed. It can extract all knowledge from decision information systems. Comparison tests between EAASDR and ID3 in 16 UCI data sets show that the algorithm is prior to ID3 in the accuracy of rule set and the average condition number of rule sets. A new rule measure criterion of certainty and consistency is proposed in order to accurately reflect the performance of all decision rules extracted from decision table.

  • GAO Wei; WANG Ning
    Computer Engineering. 2008, 34(6): 25-27. https://doi.org/10.3969/j.issn.1000-3428.2008.06.008
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    This paper applies Support Vector Machine (SVM) based on the rule of structural risk minimization to the reverberation time series prediction, and compares the predict results with Radial Basic Function(RBF) neural network. Experimental results of an ocean reverberation show that the SVM method is more effective than RBF and suitable to predict the reverberation time series.
  • MENG Liang; FANG Jin-yun; HAN Cheng-de
    Computer Engineering. 2008, 34(6): 28-29. https://doi.org/10.3969/j.issn.1000-3428.2008.06.009
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    With respect to triangle meshes, this paper proposes a symmetry edge dual-circulation linked list structure. Symmetry edge means that one edge is expressed by two directed edge. Dual-circulation linked list means that these edges take two endpoint of one edge as original point, and by same original point relation, it can associate clockwise and anticlockwise between each other. This data structure can conveniently maintain triangle meshes topology structure, and provide several pseudocode implementation of triangle meshes basic operations. Compared with general purpose polygonal meshes data structure, the structure has the advantage of easy understanding, convenient operation and thrifty memory usages.
  • ZHANG Ying; WANG Yao-nan
    Computer Engineering. 2008, 34(6): 30-32. https://doi.org/10.3969/j.issn.1000-3428.2008.06.010
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    The method based on Generalized Discriminant Analysis(GDA) is proposed for face recognition. Data points are mapped by means of nonlinear kernel function to high dimensional feature space to solve the problem in linear discriminant analysis algorithm, thus nonlinear characteristics of judgment can be available in input space, which is well adapt to facial illumination, expression, posture and other complicated changes. Experimental results show that GDA can get higher classification accuracy rate than Eigenfaces algorithm and Fisherfaces algorithm with less eigenvectors.
  • WANG Ling-ling; ZHANG Guo-yin; MA Chun-guang
    Computer Engineering. 2008, 34(6): 33-34. https://doi.org/10.3969/j.issn.1000-3428.2008.06.011
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    A new concept called forward-secure ring signature scheme based on conic curve over Zn is proposed. The scheme considers the key exposure problem, and adopted difficulties of factoring large integer and computing discrete logarithm, which strengthens the performance of the security. Because the whole signature is operated in conic curve over Zn, the scheme is easier to accomplish for embedding plaintext, computing element order and points in curves, and speeding up the inverse operation.
  • LI Kai; CUI Li-juan
    Computer Engineering. 2008, 34(6): 35-37. https://doi.org/10.3969/j.issn.1000-3428.2008.06.012
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    From point of view of diversity, the paper studies ensemble learning algorithms based on feature sets and data. Methods of creating diversity for these ensemble learning algorithms are analyzed. And experimental studies for using decision trees and neural networks as basis models are conducted on 10 standard data sets. The results show that performances of ensemble learning algorithms depend on character of data sets, method of creating diversity, and etc. In general, performances of ensemble learning algorithms based on data are superior to one based on feature sets.

  • JIAO Hui-ying; AN Jian-ping
    Computer Engineering. 2008, 34(6): 38-40. https://doi.org/10.3969/j.issn.1000-3428.2008.06.013
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    A channel estimation method based on parametric channel model using pilots in STC-OFDM systems is proposed here. The channel frequency response of the pilots is firstly estimated using LS algorithm, and then the correlation matrix of the channel is estimated by using the time-average channel correlation matrix in place of the statistical correlation matrix. The number of the multi-path is estimated by low rank Eigen-value decomposition and the time delay is estimated by using Estimation of Signal Parameters via Rotational Invariance Techniques(ESPRIT). The entire channel frequency response is interpolated in time and frequency domain. The method need not know the prior information of channel, and the simulation results show the efficiency of the proposed method.


  • ZHAO Guo-sheng; WANG Hui-qiang; WANG Jian
    Computer Engineering. 2008, 34(6): 41-42. https://doi.org/10.3969/j.issn.1000-3428.2008.06.014
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    This paper proposes a quantitative analysis model for information system survivability based on conflict analysis method. Each player’s efficiency matrix on its credible motion collection can be obtained based on the three dimensional state space of conflict; then the player whose desires moving are strongest initiates the moving, thus the overall state transition matrix of information system is gotten. The final result of situation, and changing the stability analysis of conflict into a Markov analysis process is discussed. Numerical results indicate that the proposed method may effectively be applied in the quantitative analysis of survivability.
  • QU Li-ping; LIU Da-xin; YANG Jing
    Computer Engineering. 2008, 34(6): 43-44. https://doi.org/10.3969/j.issn.1000-3428.2008.06.015
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    This paper proposes an automated approach to refactoring object oriented programs to the aspect-oriented paradigm. The approach is based upon the application of two steps: mining and refactoring. After mining potential crosscutting concerns, the refactoring phase transforms crosscutting concerns to a new aspect. This paper presents the results of an evaluation in which about 13000 LoC program is refactored.
  • LI Ling-zhi; DING Qiu-lin
    Computer Engineering. 2008, 34(6): 45-47. https://doi.org/10.3969/j.issn.1000-3428.2008.06.016
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    Anycast is a kind of network communication service, and it is vital in VoD domain and so on. This paper proposes the question model of QoS anycast flows routing optimization. And it gives genetic algorithm expressions of the QoS constraint and the optimal objective such as end-to-end delay, server load and networks traffic. It demonstrates the important steps and implementation process of the algorithm solution. Simulation results show that the algorithm can implement anycast routing combinatorial optimization under QoS constraint.
  • GUI Jin-song; CHEN Zhi-gang; HU Yu-ping;
    Computer Engineering. 2008, 34(6): 48-50. https://doi.org/10.3969/j.issn.1000-3428.2008.06.017
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    Because current grid virtual organization access control models do not support grid workflow authorization effectively, a Grid Workflow Access Control Model(GWACM) is proposed. Delegation step, delegation unit and their dependency relationships are defined to formally describe inherent restriction relationships between flow tasks. Life period model of delegation step is described, arithmetics of constructing contexts of delegation steps and delegation units are presented, and dynamic management of delegation permissions is effectively supported.
  • Software Technology and Database
  • ZHU Jian-ping; LE Yan-bo
    Computer Engineering. 2008, 34(6): 51-53. https://doi.org/10.3969/j.issn.1000-3428.2008.06.018
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    The fitness of time is seldom illustrated by traditional association rules. Temporal association rules are improved by regarding every association rule with valid time area. Weighted temporal association rule is presented in this paper based on these researches, which can reflect the time value of data and the time tendency of discovered rules, and the results of different association rules mining on the same data are also compared and achieve a fine performance.
  • LI Jian-hui; SHE Huai-hua; YAN Bao-ping
    Computer Engineering. 2008, 34(6): 54-56. https://doi.org/10.3969/j.issn.1000-3428.2008.06.019
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    This paper proposes a metadata based approach for semantic integration of relational databases, through which relational databases can be dynamically translated to virtual Resource Description Framework(RDF) views according to a domain ontology, which enables both people and machine to understand and process the “smart data”. It introduces the semantic integration framework, analyzes the semantic mapping principle from relational databases to domain ontology, and gives the metadata model and approach to decompose and translate semantic query to distributed relational databases query. The implementation of a prototype is also introduced.
  • LIU Pei-jiang; FU Xiu-fen; CHEN Chang-yao
    Computer Engineering. 2008, 34(6): 57-59. https://doi.org/10.3969/j.issn.1000-3428.2008.06.020
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    Most of advanced workflow management systems are kinds of applications based on the database system, and it has been an bottle neck in data connection and exchange with database. This paper proposes a new kind of fruition of workflow management system based on the technology of active database and the theory of Event Condition Action(ECA) rule. A preliminary exploration is made into the reference model of implementation of workflow management system based on active database. Its reasonableness and feasibility are confirmed compared with traditional workflow reference model.
  • LIU Huan-zhou; MIAO Huai-kou
    Computer Engineering. 2008, 34(6): 60-62. https://doi.org/10.3969/j.issn.1000-3428.2008.06.021
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    This paper proposes a conception of Logic Component (LC), which divides the system-under-test into LCs and ultimately mapping LCs to physical components. Digraphs are used to represent the structure relationship between LCs, and automata are used for action relationship. Interactions between LCs are described by the combination of automata, which use a created action mapping table to generate test cases. This article also proposes a test criteria and a LC sequence coverage according to this criteria.

  • GUO Bing-xuan; ZHANG Jing-li; ZHANG Zhi-chao
    Computer Engineering. 2008, 34(6): 63-64. https://doi.org/10.3969/j.issn.1000-3428.2008.06.022
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    Due to the characteristics of geographical information data, when massive spatial data processed with computer, frequent data interaction between external memory and internal memory will lead to higher occupancy, and lower efficiency. But memory pool can be used to dispatch spatial data and enhance efficiency. Based on a variety of specific map using models, adoption of the technology utilizing different memory pools page replacement algorithm can effectively reducee the interaction between external memory and internal memory. Experimental results show the proposed solution is ideal for GIS system in the embedded equipment with limited memory capacity.
  • LI Li; ZOU Hai
    Computer Engineering. 2008, 34(6): 65-66. https://doi.org/10.3969/j.issn.1000-3428.2008.06.023
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    In rough set theory, the discernibility matrix is used on the whole data set. In this paper, the application of extended discernibility matrix is presented. The discernibility matrix can be used to not only the whole data set but also the partial data. An algorithm is introduced, which is used to find the attributes that negate the high reliability decision rules on some condition attributes. It selects anyone among all the condition attributes and decision attributes to calculate its indiscernibility binary relation. The algorithm is based on equivalence classes and uses a part of data of the whole data set to construct the discernibility matrix. The question can be solved by the discernibility function. An experiment with medical data is presented. Experimental results show that the algorithm is more efficient and has less space complexity and time complexity .
  • WANG Shu-feng; WU Geng-feng; PAN Jian-guo
    Computer Engineering. 2008, 34(6): 67-69. https://doi.org/10.3969/j.issn.1000-3428.2008.06.024
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    By regarding the significance of attributes defined from the viewpoint of information theory as heuristic information, and introducing the heuristic information into genetic algorithm which takes attribute lengths as fitness function, this paper proposes an effective heuristic genetic algorithm for minimizing relative reduction. It uses the heuristic genetic algorithm to select the important attributes from the original decision table, and forms an optimal decision table which contains minimal missing value. A method for extracting rules in optimal decision table based on attribute extension is presented. It can get the rule sets without estimating missing attribute value. Experiments justify that the accuracy of obtained rule set is better than the highest accuracy among those of the estimating missing attribute value methods.
  • XU Gui-ping; CAI Bo-ke
    Computer Engineering. 2008, 34(6): 70-71. https://doi.org/10.3969/j.issn.1000-3428.2008.06.025
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    The aim of real-time main memory database systems is to avoid the operation of I/O. But in the recovery subsystem, there are two I/O operations that are necessary, namely, data refurbishing in MDB to the disk and log writing. Therefore, a system with two nodes is designed in which each node can work independently. Advantages of the system are that the recovery subsystem need not write the data in the main memory to the disk during the system running and the database system can keep working without ceasing if one node fails.
  • XIAO Man-sheng ; LIU You-shi; YANG Di-lan
    Computer Engineering. 2008, 34(6): 72-73. https://doi.org/10.3969/j.issn.1000-3428.2008.06.026
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    This paper analyzes the process about the integration of the C-Omega language and the query language, points out the merit of using inquiry operator in the integration, and proposes a solution about impedance mismatch on operating the data set based on the C-Omega and query language on basis of this. The solution can solve the contradiction about the differences of the programming style and the data type in developing the software between the query language and the host language, and it also can discover errors earlier in the database.
  • ZHAO Yi; TANG Rong-feng; CHEN Huan; XIONG Jin; MA Jie;
    Computer Engineering. 2008, 34(6): 74-76. https://doi.org/10.3969/j.issn.1000-3428.2008.06.027
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    File systems on the servers require both massive capacity and high I/O performance for large quantities of concurrent accesses. In this paper, a technology of building a logical file system by integrating a number of physical file systems is presented. It integrates the bandwidth and capacity of those physical file systems, and combines the performance of both meta-data and file data from different kinds of existing file systems. Performance evaluation result shows that the logical file system technology is an effective way of building high performance file system with the ability to support highly concurrent accesses.
  • CHEN Jun; MIAO Yan-chao; ZHOU Ying-chao; MA Jie; YANG Xiao-jun;
    Computer Engineering. 2008, 34(6): 77-79. https://doi.org/10.3969/j.issn.1000-3428.2008.06.028
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    This paper introduces a prototype of a multiprocessor system based on NUMA and analyzes its physical memory management in operating system. A global shared memory system is implemented based on the system, and it can allow operating system to use system-wide memory to decrease the execution time of the application. Results show that the system supports memory-intensive applications better.
  • SONG Gang; JIANG Meng-qi; ZHANG Yun-quan; LI Yu-cheng
    Computer Engineering. 2008, 34(6): 80-81. https://doi.org/10.3969/j.issn.1000-3428.2008.06.029
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    With the release of the Intel and AMD’s dual-core and muti-core processor, parallel computing becomes pervasive. To make effective use of the muti-core processor, the original sequential program has to be parallelized. In this paper, the OpenMP is used to parallelize the element computation subroutine of finite element method. And the test on a SMP node with dual-CPU of a cluster shows that the performance is improved almost twice compared with the original sequential program.
  • WANG You-rong; ZENG Qing-kai;
    Computer Engineering. 2008, 34(6): 82-84. https://doi.org/10.3969/j.issn.1000-3428.2008.06.030
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    Inlined reference monitor is an important way for monitoring program behavior dynamically. The different ways, which various IRMs use to ensure the safety and efficiency, lack a common architecture. As a result, it is very difficult to integrate them and the cost to develop new IRMs is raised. This paper proposes a general framework called IPBMF(Inlined Program Behavior Monitoring Framework), which provides a general mechanism to guarantee the non-circumventability, integrity and efficiency of RMs. It also solves the problem of reusing and integrating existing IRMs.So IPBMF can well support dynamic program behavior monitoring.
  • SHI Xiang-bin; ; WANG Yue; LI Qiang; WANG Xiao-guang; WANG Jing
    Computer Engineering. 2008, 34(6): 85-87. https://doi.org/10.3969/j.issn.1000-3428.2008.06.031
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    Mobile agent brings new problems about real-time scheduler in the applications of P2P MMOG. This paper proposes a dynamic priority-variation strategy which can schedule the players’ tasks dynamically according to the trusted degree of agent services, the CPU occupating coefficient of agent service in the players’ computers, the network traffic of the players’ computers and the tasks’ latency time in the scheduler queue. The simulation results show that this strategy fulfills the real-time demand of the games, shortens the system latency time, and solves the problem about load balance in P2P MMOG.

  • YANG Xin; LI Chong
    Computer Engineering. 2008, 34(6): 88-89. https://doi.org/10.3969/j.issn.1000-3428.2008.06.032
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    IA64, as a processor of 64-bit, supplies more ILP, and it stands for the developing orientation of new microprocessor. This paper introduces the representation of IA-64 instructions based on SLED and the reverse tool which produces by MLTK, discusses the design and implementation of IA64 instruction decoder. It is very significant for automatic analysis and transform of IA64 binary instruction streams in the realization of automatic translation of binary and reverse direction engineering based on the descriptions of computer and operating system.
  • XIE Zhen-hua; LAI Sheng-li; CHEN Peng
    Computer Engineering. 2008, 34(6): 90-92. https://doi.org/10.3969/j.issn.1000-3428.2008.06.033
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    Against the common tag collision problem in Radio Frequency Identification (RFID) system, the tag identification ability is discussed when disordered and successive ID number is encountered. A binary-tree searching anti-collision algorithm based on dynamic adjustment and a roll polling algorithm are designed to solve the corresponding problem. Their algorithm performances are analyzed and compared. Simulation shows that the dynamic adjustment algorithm can be effectively applied to ISO/IEC 18000-6B standard. Conclusions point out that both algorithms have well practical value.
  • LI Ai-guo; ZHANG Yan-li
    Computer Engineering. 2008, 34(6): 93-94. https://doi.org/10.3969/j.issn.1000-3428.2008.06.034
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    It is an important task to generate test data automatically within the software testing process. The previous approaches of generating structural test data are mostly based on variant Genetic Algorithms(GA). These approaches have two shortcomings: the algorithms are too complex to use, and the parameters of the algorithms are not easy to be set by users. A novel approach for generating structural test data based on Particle Swarm Optimizer(PSO) is proposed. The approach employs the summation of branch-function as fitness function of PSO. Two triangle discrimination programs are used to experiment. The experimental results show that the approach is more efficient than GA based approach: when the number of particles of PSO is equal to the size of GA, the mean number of iteration of proposed approach is about 1/16 as many as that of GA-based approach.
  • LIU Yin; YANG Shi-ping
    Computer Engineering. 2008, 34(6): 95-97. https://doi.org/10.3969/j.issn.1000-3428.2008.06.035
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    Packet classification is widely used in many network services, and the qualities of these network services are basically determined by the performance of packet classification these network services use. RFC algorithm is a representative packet classification algorithm and it behaves fast in classification, but the storage it costs is so large that implementation of RFC algorithm is extravagant. This paper introduces a fast packet classification algorithm applying in multi-fields, which is based on recursive flow classification algorithm. By using Hash technology, it costs less storage than RFC algorithm and keeps high speed.
  • Networks and Communications
  • ZHANG Zhan-guo; LIU Shu-fen; BAO Tie; ZHANG Xin-jia; WANG Xiao-yan; ZHANG Chan
    Computer Engineering. 2008, 34(6): 98-100. https://doi.org/10.3969/j.issn.1000-3428.2008.06.036
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    Topology discovery is an important foundation for network management. This paper proposes a new physical topology discovery algorithm relying on Spanning Tree Protocol(STP). The algorithm gets spanning tree status information of each switch by SNMP. According to STP, physical topology of the network is derived. Comparing with other existing algorithms, the algorithm does not require that the FDB information of each bridge is complete. Meanwhile, it can find backup link and equipments that do not support SNMP such as hub and dump switches. Experiments show that the algorithm is an accurate, comprehensive topology discovery algorithm.
  • GAO Li-wen; YAO Yao-wen
    Computer Engineering. 2008, 34(6): 101-102. https://doi.org/10.3969/j.issn.1000-3428.2008.06.037
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    This paper puts forward a Linear Optical Network Protocol(LONP) based on Metropolitan Area Network(MAN) protocol DQDB. The pattern of building network is an important tache of it. The paper introduces how to build a large MAN with linear subnets, and studies the problem of extending the linear subnet, which deals with an arithmetic, used for determine whether to extend to linear subnet or not, and a method to carry out the extending of the linear subnet. As an application example, it gives a MAN layout of Guangzhou city.
  • WANG Hui; LUO Jun-yong; KOU Xiao-rui
    Computer Engineering. 2008, 34(6): 103-105. https://doi.org/10.3969/j.issn.1000-3428.2008.06.038
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    The packets of OSPF protocol contains topology information of network. This paper proposes an arithmetic which uses database description packet and link state update packet of OSPF protocol. The main idea of this arithmetic is simulating the process of router to construct link state database, which is classified by area, and calculates the topology in every area, then uses border router to connect the area topology to get the whole network topology. Experimental result illustrates that the arithmetic can capture network topology very well.
  • LU Yang; CHEN Ming
    Computer Engineering. 2008, 34(6): 106-108. https://doi.org/10.3969/j.issn.1000-3428.2008.06.039
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    P2P lookup protocol based on DHT has become a hot-spot field. Focusing on the problem of hot spots and inefficient routing, a new tree-based lookup protocol Treed is presented. Treed introduces landmark in order to divide nodes into different regions, and constructs lookup tree according to landmark region. The experimental results show that Treed is highly effective in distributing routing traffic, and significantly reduces lookup latency.
  • GUO Qiu; WANG Li; WEI Ying; GUO Lu
    Computer Engineering. 2008, 34(6): 109-111. https://doi.org/10.3969/j.issn.1000-3428.2008.06.040
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    This paper discusses the bandwidth allocation scheme in multimedia file server, puts forward a automatic bandwidth allocation scheme for different applications in single-disk. The bandwidth allocation techniques consist of two key components: a workload monitoring module that efficiently monitors the load in each application class, and a bandwidth manager module that uses these workload statistics to dynamically determine the allocation of each class. It raises the manageability of the multimedia file server and provides stable behavior even during transient overloads.
  • WU Hua; ZHOU Ming-zhong; GONG Jian
    Computer Engineering. 2008, 34(6): 112-114. https://doi.org/10.3969/j.issn.1000-3428.2008.06.041
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    This paper studies TRACEs with different characteristics. The flows length distribution characteristics are discovered by analyzing those TRACEs. Based on the discussions, the empirical model of IP flows distribution for large-scale networks is proposed based on the characteristics analysis, whose precision is better than Pareto model, and the complexity is less than double Pareto model. Goodness-of-fit test is employed to inspect the effect of this model and its parameters. And then, this empirical model is contrasted with other distribution models presented by former researchers, and the same and different characteristics among all of these models are discussed, and so do their causes. The possible tendency of IP flow distribution is forecasted based on those discussions.
  • WEI Yuan-lei; QI Yu-qing; HU Xi-hong
    Computer Engineering. 2008, 34(6): 115-117. https://doi.org/10.3969/j.issn.1000-3428.2008.06.042
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    The basic performance parameters of Local Area Network(LAN) system are summarized as follows: network connectivity, transmission rate, throughout, transmission latency, packet loss rate, link utilization, frame error rate, broadcast frame rate, multicast frame rate and collision rate. The normative test methods are presented for the former parameters. The sampling criteria of links are proposed for acceptance test of LAN systems. Test results validate the applicability and operability of the methods.
  • ZHOU Li-ping; LI Zhi-shu; YIN-Feng; LEI Qi-min; NI Jian-cheng; LI Qing
    Computer Engineering. 2008, 34(6): 118-120. https://doi.org/10.3969/j.issn.1000-3428.2008.06.043
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    Active Network Congestion Control(ACC) uses dropping packets to relax congestion which can not satisfy the current network. This paper puts forward an improved ACC algorithm which can avoid and control congestion through modifying the congestion parameters carried with every active packet by congestion control codes in active routers. Experimental results show that the algorithm keeps high efficiency, good fairness, and rare packet dropping.
  • XING Chang-ming; YANG Lin; LIU Fang-ai
    Computer Engineering. 2008, 34(6): 121-123. https://doi.org/10.3969/j.issn.1000-3428.2008.06.044
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    Replica mechanism is the efficient method of improving grid performances and reducing client delay. Replica placement strategy is the key problem of replica mechanism. This paper introduces the architecture of education resource grid. According to the architecture, it presents three dynamic replica location strategies, optimizes three strategies from different aspects, and reduces client delay on the premise of keeping the storage space of replica. Experimental results show that strategies are effective.
  • YANG Yan; TAN Cheng-xiang
    Computer Engineering. 2008, 34(6): 124-126. https://doi.org/10.3969/j.issn.1000-3428.2008.06.045
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    With some insecure factors existing Short Message Service(SMS) system which is on the basis of wireless network, such as the short message will be filched, intercepted and lost. GSM modem based on SMS system for secure communication is discussed and implemented. Solutions of certificate and authentic bytes added in the SMS package are analyzed for secure authentication of the system, and encryption & decryption are called to the SMS package. The study shows that it is necessary to ensure the secure of the SMS system by mutual authentication and encryption.
  • ZOU Dong-yao; SONG Mei-na; SONG Jun-de
    Computer Engineering. 2008, 34(6): 127-128. https://doi.org/10.3969/j.issn.1000-3428.2008.06.046
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    In structured P2P systems, the topology of underlying physical network is not considered on building logical overlay, whose route mechanism is designed from nodes border upon logic, so neighboring nodes in physical network have large delay. A P-Chord system model is proposed on the basis of Chord in the paper, which uses the topology of physical network and adds neighbor route table. The experimental results show there are preferable improvements in route delay and hops of overlay network when P-Chord is compared with Chord.
  • YU Guo-fang; WANG Yao-cai; ZHUANG Li-yun; JIA Dong-qing
    Computer Engineering. 2008, 34(6): 129-130. https://doi.org/10.3969/j.issn.1000-3428.2008.06.047
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    Based on analysis and comparison of existed load balancing program on the cluster server distributor, this paper studies a kind of dynamic fuzzy queue length distributor, which is suited to the small Web server clusters. The distributor focuses on the quality of service regulation, and overall cluster load balance. Feasibility of the scheme on the simulation platform programmed by Visual C++ is tested. Experimental results show that the scheme is effective.
  • Security Technology
  • ZHANG Song-hong; WANG Ya-di; HAN Ji-hong
    Computer Engineering. 2008, 34(6): 131-133. https://doi.org/10.3969/j.issn.1000-3428.2008.06.048
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    The multi-step attack is one of the primary forms of the current attack. Intrusion detection system only detects attack, but cannt forecast next attack. This paper presents an approach to forecasting attack based on HMM after analyzing the defaults of some approaches to forecasting attack. To recognize the attacker’s attack intention and forecast next possible attack using the Forward and Viterbi algorithm. Experimental results prove the validity of the approach.

  • ZHAO Pei-dong; XIE Jian-ying
    Computer Engineering. 2008, 34(6): 134-136. https://doi.org/10.3969/j.issn.1000-3428.2008.06.049
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    A coordinate system of the original image is established by using the feature points which satisfy with a function relation. After the original image transforms into a standard coordinate system, a rectangle ring watermark is adaptively embedded in Discrete Wavelet Transform (DWT) domain from the center to margin by level and level. Then the feature points are embedded into the image and searched before watermark detection. Regardless of the shape that the host image is cropped, the watermark is detected from center to margin after the watermarked image is transformed into the standard coordinate system. The watermark can be detected without the size of original image. The detection is blind. Experimental results show that the proposed scheme is effectively against general and crop attacks.
  • ZHANG Le-jun; WANG Wei; GUO Lin; YANG Wu; YANG Yong-tian
    Computer Engineering. 2008, 34(6): 137-139. https://doi.org/10.3969/j.issn.1000-3428.2008.06.050
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    This paper presents a survivability quantitative analysis method for network information system based on intrusion scenario. The method indicates that the survivability is not only relevant to the system but also to its running environment. So the survivability computing formulas are given according to attack scene. A case study proves the correctness and effectiveness of the method, it can find out the weak nodes that can be damaged by attacker and give the network administrator valuable suggestions to enhance system survivability.
  • CHEN Jian-hui ; XU Tao
    Computer Engineering. 2008, 34(6): 140-142. https://doi.org/10.3969/j.issn.1000-3428.2008.06.051
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    Authentication protocol has a DoS attack weakness. Based on the idea of cookie solution and proof of work, this paper uses weak authentication and strong authentication, presents the security solution for protecting two-party authentication protocols against DoS attack, gives the detail and some experimental data, analyses the solution’s security. It improves the Lowe’s NSPK protocol using the solution, and analyses the improved protocol’s performance.
  • PU Fang; SUN Dao-qing; CAO Qi-ying; CAI Hai-bin; LI Cai-xia
    Computer Engineering. 2008, 34(6): 143-144. https://doi.org/10.3969/j.issn.1000-3428.2008.06.052
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    In order to solve the contradiction between information sharing, cooperation and security privacy in the ubiquitous computing environment, a dynamic and semantic security policy management mechanism for ubiquitous computing is presented. The mechanism imports unified ontologies knowledge base. Ontologies service varies with the context information and adjusts policy service to act on the managed targets. The policy management framework, dynamic policy implementation and policy specification are described. A typical example of the ubiquitous computing scenario is given to show how to apply the mechanism.

  • MENG Tao; DAI Zi-bin
    Computer Engineering. 2008, 34(6): 145-147. https://doi.org/10.3969/j.issn.1000-3428.2008.06.053
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    This paper analyzes symmetry ciphers algorithm, summarizes kinds of modulo operations, contrives high-performance and reconfigurable modulo unit, which supports modulo28 addition, modulo28 subtraction, modulo28 multiplication, modulo216 addition, modulo216 subtraction, modulo216 multiplication, modulo(216+1) multiplication, modulo232 addition, modulo232 subtraction, modulo232 multiplication and modulo(232-1) multiplication, and also supports any two parallel operations of modulo28 addition, modulo28 subtraction, modulo28 multiplication, modulo216 addition, modulo216 subtraction, modulo216 multiplication, modulo(216+1) multiplication. Universal instructions of the unit is given. Experimental results show that the modulo unit is effective.
  • 于 江;戴紫彬;张永福
    Computer Engineering. 2008, 34(6): 148-150. https://doi.org/10.3969/j.issn.1000-3428.2008.06.054
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    This paper analyzes the structure of Windows2000 NDIS architecture, and introduces a design project of encrypt Ethernet card communication system. By discussing the design and implementation theory of the link layer communication system based on NDIS, it presents the implementation of the communication encrypt in miniport driver and analyzes the use and management method of the key in the encryption module. This encryption communication system realizes transparent encryption and high efficiency.
  • XU Peng-fei; SHEN Lei
    Computer Engineering. 2008, 34(6): 151-152. https://doi.org/10.3969/j.issn.1000-3428.2008.06.055
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    An improved BP algorithm is proposed,in the algorithm,the learning rate α is not given by experts, but the best value is computed during learning. The experimental results indicate that this improved algorithm can increase learning speed and shorten training time. have become a part of security infrastructures. As high false alarm rate exists in current network intrusion detection systems, this improved algorithm can improve the intrusion detection rate.
  • TANG Zhen-jun; WEI Wei-min
    Computer Engineering. 2008, 34(6): 153-154. https://doi.org/10.3969/j.issn.1000-3428.2008.06.056
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    This paper proposes a scrambling scheme for color image without iterative computation. By shifting the rows and columns, the relativity among the adjacent pixels is scrambled. To improve the security, the method of storing color components in different pixels is applied. During the shift, different color components have different parameters. Then image is divided into blocks. XOR operation is used to alter the pixel value in each block and the operand of XOR is determined by the position of pixel. Theoretical analysis and experimental results show that the algorithm is effective and secure. It is faster than Arnold transform method.
  • DING Guang-hua; LIU Jia-yong; SUN Ke-qiang
    Computer Engineering. 2008, 34(6): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2008.06.057
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    The paper proposes an information-hiding method based on the structure of XML, based on analysis of the data structure of XML file. The secret data is preprocessed, then according to the structure of the elements, the secret data is hided by replacing the element name with thesaurus. Experimental results prove the method is easy to implement, and has high expansibility and high security.
  • CHENG Lei; SI Tian-ge; DAI Yi-qi
    Computer Engineering. 2008, 34(6): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2008.06.058
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    This paper proposes a new solution to the security of LAN in perspective of architecture. There are two characteristics in this solution: consolidating discrete storage devices in the LAN by means of transparence computing technology, the LAN has a star topology with a central monitor, which can proactively regulate the network traffic. With mandatory access control over the communication among the entities in the network, the monitor can filter the traffic and dynamically isolate the physical connections among host computers, and between host computers and outside network.
  • ZHOU Jia-jun; WANG Ting-ting
    Computer Engineering. 2008, 34(6): 161-163. https://doi.org/10.3969/j.issn.1000-3428.2008.06.059
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    The commonality, flexibility and extensibility of the worm diffusion are limited, so an auto-generation model of worm diffusion strategy based on diffusion strategy tree is proposed. Based on the model, a description language is designed to descript the procession of worm diffusion and implement the worm diffusion with language interpreter. The paper formally demonstrates the worm diffusion description ability of the language, constructs the framework of the model, and expounds its work flow. Theoretically the model can achieve more prevalent diffusion process.
  • ZHAO Ting; WANG Xiao-feng; WANG Shang-ping; WU Xiao-feng; GUO Hu
    Computer Engineering. 2008, 34(6): 164-166. https://doi.org/10.3969/j.issn.1000-3428.2008.06.060
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    The tripartite key agreement protocol is more efficient than previous protocol, but it is unable to authenticate the user’s identity and is vulnerable to man-in-the-middle attack. This paper extends it to multi-party, and proposes two ID-based key agreement schemes. The new schemes are able to authenticate the user’s identity, and the signature to realize the function is a short signature, so the executing phase is efficient. Password evolution scheme is introduced in order to improve its security. The new schemes have many properties such as equal contribution, non-key control, against man-in-middle attack, etc.
  • CAO Fang; DU Xue-hui; QIAN Yan-bin
    Computer Engineering. 2008, 34(6): 167-169. https://doi.org/10.3969/j.issn.1000-3428.2008.06.061
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    In order to solve the security issues of the binding update message in the IPv6 route optimization process, this paper presents a new security mechanism based on Cryptographically Generated Addresses(CGA) through the analysis of the Return Routability Procedure (RRP) and CAM protocols. Security analysis proves that the mechanism can authenticate the nodes based on IPv6 address without PKI infrastructure, and prevent the forged binding update messages and the reflecting attack.
  • LU Ke; ZHOU Bao-qun; WANG Hui-fang
    Computer Engineering. 2008, 34(6): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2008.06.062
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    This paper analyzes the administrative model of RBAC and Usage Control(UCON)model, and points out the deficiency of UCON core model. Based on the results, authorization mechanism of separated rights grant and revoke is introduced into UCON model, and a role-based usage control model with time character is presented. The description of the model and its implementation administration are presented.
  • JIANG Xiao-biao; TANG Guang-ming; SUN Yi-feng; HUANG Hao
    Computer Engineering. 2008, 34(6): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2008.06.063
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    This paper achieves the qualification of theoretic-security of steganography based on concrete memoryless carriers, by restricting the visual and statistical characteristics of the carrier. It releases the expressions of the capacity of steganography threatened by active or passive attackers. It analyzes the countermeasure essence and defines two strategy sets, including the safe cryptoclastic strategy set and active attack one.
  • LIU Wan; TAN Ming; ZHENG Jun
    Computer Engineering. 2008, 34(6): 176-178. https://doi.org/10.3969/j.issn.1000-3428.2008.06.064
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    Trusted computing technologies typically used in trusted terminal, trusted connect, trusted network, focusing on the self immunity of terminal and network, put forwards the thinking which accomplishes security in the way of building trust. It becomes the first choice of many information security companies. This paper chooses the trusted-chain model of trusted terminal technology as the research object, studies the conception model of trusted-chain, gives the modeling process, the realization of the model’s antetype, and points out the advantages of the model compared with the conditional information security model.

  • Artificial Intelligence and Recognition Technology
  • SHEN Jian; SHE Shi-gang; WANG Kai; HUANG Yi-chang
    Computer Engineering. 2008, 34(6): 179-181. https://doi.org/10.3969/j.issn.1000-3428.2008.06.065
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to decrease operation costs and improve the performance of networks, a new and efficient swarm intelligence search method based on particle swarm optimization algorithm for solving the problem of link Capacity and Flow Assignment(CFA) in computer communication networks is presented. Results of a great number of computer simulation experiments show that, not only the effectiveness of particle swarm optimization algorithm for solving CFA problem is borne out, but also, compared with the traditional lagrangean relaxation and subgradient optimization method, the obtained solution has higher accuracy, and compared with the genetic algorithm, the superiority of particle swarm optimization algorithm is further shown in the complexity and running speed.
  • WANG Tong; HE Pi-Lian
    Computer Engineering. 2008, 34(6): 182-184. https://doi.org/10.3969/j.issn.1000-3428.2008.06.066
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to identify the user in the Web mining, an idea, which uses the biometric recognition technology, is put forward. At the same time, an iris identification technology based on the hidden Markov model is proposed, too. The robust of iris matching can be achieved by only depending on the orientation field of the iris and less sensitive to the noise and the distortions of the iris image. By recognizing the users affirmatively, the shortcoming of the current Web architecture, the non-state property, can be overcome. By this way, the Web log can be sliced up by the user dimension. This makes the mining result can be used to fit the need of the personal requirement.

  • WANG Dong; WU Xiang-bin; MAO Xian-cheng; LIU Wen-jian
    Computer Engineering. 2008, 34(6): 185-187. https://doi.org/10.3969/j.issn.1000-3428.2008.06.067
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For resolving the two problems, premature convergence and slow-footed convergence, when utilizing particle swarm optimization to solve combinatorial optimization problem, it is necessary tointegrate particle swarm optimization and local search optimization algorithms. This can enhance to restrain premature of particle swarm optimization, and accelerate the convergence rate of the algorithms. The solution quality and solution efficiency of local search algorithms can be improved through establishing reference optimization edge set used by local search algorithms. New hybrid particle swarm optimization utilizing the above-mentioned methods converges high efficaciously to global optimal solutions of middling and small scale TSP. The results of numerous experiments indicate that the new algorithm is efficacious.
  • HU Xue-hai; WANG Hou-jun; GU Tian-xiang
    Computer Engineering. 2008, 34(6): 188-190. https://doi.org/10.3969/j.issn.1000-3428.2008.06.068
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    The current decision fusion algorithms of distributed system isn’t fit to the practical application, because these algorithms reckon without alterable target and need the prior probability of the testing-target of given system. This paper develops a new method for self-adaptive decision fusion based on Bayesian, which estimates target by accumulation and volatility strategy of pheromone as ant-colony. Test result shows that detection performance possesses good convergence property with increasing feedback stage, and is suitable for variable systems by changing self-adaptively correlative parameter.
  • 周中华;吴根秀;连 钢;吴志远
    Computer Engineering. 2008, 34(6): 191-193. https://doi.org/10.3969/j.issn.1000-3428.2008.06.069
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    In rough set theory, accuracy measure is an important numerical characterization that quantifies the imprecision of a rough set caused by its boundary region. However, the traditional accuracy measure does not take into consideration the granularity of the partition induced by an equivalence relation. This paper analyzes the limitation of the traditional accuracy measure and proposes a new kind of definition of accuracy measure based on the one proposed by Baowen Xu et al. Some of its good properties are proved. It is more suitable to measure the imprecision of rough sets and its algorithm is simpler than Xu Baowen et al’s, which are illustrated by examples.
  • WU Zhong-qin; HUANG Xuan-jing; WU Li-de
    Computer Engineering. 2008, 34(6): 194-195. https://doi.org/10.3969/j.issn.1000-3428.2008.06.070
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a new question-focused summarization method based on Semantic Relational Triple(SRT). After syntax parsing, it abstracts the semantic relational triple both from sentences and questions, and calculates the similarity of triples by using search engine. The similarities of sentences and questions are calculated to form the final question-focused summarization. Experiments on authoritative corpus show that this feature outperforms classical features and its ROUGE-4 score rises by 46.4%. The system using the single feature ranks 10/32 in a global evaluation.
  • LI Lin-yi; LI De-ren
    Computer Engineering. 2008, 34(6): 196-198. https://doi.org/10.3969/j.issn.1000-3428.2008.06.071
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    Particle Swarm Optimization(PSO) is a stochastic global optimization technique based on swarm intelligence. This paper introduces aerial image texture classification. The particles in the swarm are constructed and swarm search strategies are proposed in terms of the needs of classification application after many texture features such as wavelet features and factual features extracted from texture samples. The classification method as PSO is implemented. Compared with the texture classification method based on Genetic Algorithms(GA), PSO has better search ability and the classification method based on it has higher classification accuracy and needs less computation time in the experiment.
  • NIU He-ming; ZENG Ming; ZHANG Jian-xun
    Computer Engineering. 2008, 34(6): 199-201. https://doi.org/10.3969/j.issn.1000-3428.2008.06.072
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    Because there is mismatch between the statistic data and the information of gray levels in the algorithm of global histogram equalization. An algorithm of image enhancement in spatial domain using frequency analysis as an accessorial tool has been made. It regards the wavelet information in frequency domain as the statistic data of gray levels of an image, adjusts the statistic data by subsection, makes image enhancement in spatial domain using the adjusted statistic data, and gives two evaluable index of the enhanced effect.
  • QIAN Wen-guang; LIN Xiao-zhu
    Computer Engineering. 2008, 34(6): 202-204. https://doi.org/10.3969/j.issn.1000-3428.2008.06.073
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    Corner is one of the important features of image contour. A technique for detecting corners precisely and rapidly is proposed. The technique is based on the calculation of contour sharp degree. The procedure processes the contour through Gaussian multi-scale smoothing, calculates the shape degree of each contour point within the region of local support, and determines corners by a process of corner filtering at some criteria. Rationality and feasibility of the algorithm are verified mathematically. Contrast experiments show that the new approach is robust and accurate.
  • ZHANG Guo-yun; PENG Shi-yu
    Computer Engineering. 2008, 34(6): 205-206. https://doi.org/10.3969/j.issn.1000-3428.2008.06.074
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    A method of image compression using anti-symmetrical biorthogonal wavelets is presented, where the space and the structure redundancy in the static picture are analysized. The wavelet transform coefficients of the image and their correlation information degrees are computed, and the low frequency and the high frequency part of wavelet transform are encoded respectively. Experimental results show that the proposed method has explicit performance. When testing Lena image, its PSNR is 1.42 dB higher than that of DCT.
  • HUANG Ying-jie; LU Hu-chuan
    Computer Engineering. 2008, 34(6): 207-209. https://doi.org/10.3969/j.issn.1000-3428.2008.06.075
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    An improved moving object detection algorithm is proposed. It is robust to changes in background illumination and can detect multiple moving objects accurately in various complex scenes. Generally, the shadow is also detected as moving object because of the same characters between them. Another method of shadow removal based on edge information is presented too, which is independent of the direction of shadow, and can effectively remove the cast shadow of a moving object. Implemented by computer of P4 2.0 GHz, it runs at about 20 f/s. Experiments show that the method is reliable, and can be used in relevant real-time applications.
  • ZHAO Jian-lei; WANG Hui-yuan; FANG Ying
    Computer Engineering. 2008, 34(6): 210-211. https://doi.org/10.3969/j.issn.1000-3428.2008.06.076
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    In vehicle license plate recognition systems, it is common that the background of the gray level vehicle license plate image becomes unclear or close to the color of the word because of vidicon aberration, narrow dynamic area and polluted plates, which makes it difficult to segment the characters from the plate, therefore a new method is presented, where characters of the image are enhanced by morphologic filtering using the top-hat and the bottom-hat at the same time to eliminate the negative effect of the background, and the plate image is binarized by an improved iterative method. Experimental results show that this algorithm is robust in dealing with the degraded license plates with unclear and white setting.
  • GUO Jin-yu; YUAN Wei-qi
    Computer Engineering. 2008, 34(6): 212-213. https://doi.org/10.3969/j.issn.1000-3428.2008.06.077
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    In the FLD-based recognition, the within-class scatter matrix is always singular. To overcome the above problem, a new way is to directly project the image matrix based on Two-Dimensional FLD(2DFLD). In PolyU palmprint database, this paper applies PCA, PCA+FLD and 2DFLD to extract the palmprint feature subspace. The images to be recognized are projected on small dimension subspace. A classifier to palmprint match based on cosine distance is used. Experimental results show that the recognition rate of PCA+FLD is about 1.18% higher than that of PCA. Compared with PCA+FLD, this method is able to yield recognition rate as high as 99.34%, with accuracy enhanced by 7.61%, while the feature extraction time is only 0.032 s.
  • CHEN Jing; PAN Quan-ke
    Computer Engineering. 2008, 34(6): 214-215. https://doi.org/10.3969/j.issn.1000-3428.2008.06.078
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    An improved discrete Particle Swarm Optimization(PSO) algorithm is presented to tackle the independent task scheduling problem. In the algorithm, a task based representation is designed, and a new method is used to update the positions and velocity of particles. In order to keep the particle swarm algorithm from premature stagnation, the simulated annealing algorithm, which has local search ability, is combined with the PSO algorithm to make elaborate search near the optimal solution, then the quality of solutions is improved effectively. Experimental results compared with genetic algorithm and basic PSO algorithm show that the hybrid algorithm has good performance.
  • WANG Mei; WANG Guo-hong
    Computer Engineering. 2008, 34(6): 216-218. https://doi.org/10.3969/j.issn.1000-3428.2008.06.079
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    This paper presents a method of VLP correction based on characters projection distance. It shows that the VLP characters can be extracted by concomitant and complement feature. The character is projected to vertical axis by rotating the VLP area and the tilt angle is captured by vertical projection minimum distance. The character is projected to horizontal axis by sheering the VLP area and the sheer angle is captured by horizontal projection minimum distance. Corrected image can be executed by bilinear interpolation. The method with good anti-interference does not depend on the VLP frame feature. Experiments on actual images taken under various conditions from traffic stations show good robustness and practicality.

  • CHEN Xian-fu; YAO Hai-dong; JIN Yan-hui; LU Feng
    Computer Engineering. 2008, 34(6): 219-220. https://doi.org/10.3969/j.issn.1000-3428.2008.06.080
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    This paper brings forward a stochastic variable into a typical spiking neuron model that is proposed by Izhikevich in 2003. Improvement makes neuron firing stochastically. Status of networks’ firing consisting of some these neurons is tested. The experimental results indicate that, through setting appropriate connection weights, it can obtain oscillating firing. The loop can be selected from networks by the status of special oscillating firing status. The experiment accomplishes loop memory associative, then puts forward a new train of thought to study spiking neuron’s intelligence.
  • LI Zhi-yun; XU Shi-jin; WU Gang-shan; DONG Shao-chun
    Computer Engineering. 2008, 34(6): 221-223. https://doi.org/10.3969/j.issn.1000-3428.2008.06.081
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    During an information retrieval process in digital museum, normal users may fail to locate their required resources effectively because of the lack of domain knowledge such as particular professional terms etc. This paper starts with a brief introduction on the collaborative tagging technique. After that, an experimental study on the data from delicious website is conducted, based on which some useful conclusions are drawn on how to utilize collaborative tagging technique to improve the efficiency of information retrieval. According to these conclusions, a reference information retrieval framework for the digital museum resource access is proposed.
  • WANG Jun-wen; HOU Ting-bo; ZHU Feng
    Computer Engineering. 2008, 34(6): 224-226. https://doi.org/10.3969/j.issn.1000-3428.2008.06.082
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    For the pose estimation problem using n points or n lines, this paper turns the point or line correspondences into the unified quadratic forms. Since the 2D perspective projection point or line features are corrupted by noise, it introduces EIV model to describe it. It also emploies pseudo-linearization to simplify the problem and proposes an iterative algorithm based on SVD to estimate the pose parameters. The method has a weaker dependence on the initial solution and a fast convergence. Experimental results demonstrate the reliable accuracy and robustness of the method.
  • FU Ping; LUO Ke
    Computer Engineering. 2008, 34(6): 227-228. https://doi.org/10.3969/j.issn.1000-3428.2008.06.083
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    This paper presents a clustering analysis method of immune genetic algorithm based on entropy. Immune algorithm is introduced into genetic algorithm toincorporate immune algorithm’s functions such as immune memory, self-adjustability and the keeping of the diversity. The immune-genetic algorithm based on information entropy can overcome the shortcomings of standard genetic algorithm, e. g., poor local search capability, excessive computational cost and premature convergence, etc. This algorithm adopts DNA to code the antibody, and uses information entropy to denote the affinity and the consistence of the antibodies. The converged affinity is presented to achieve self-adjustability of colony, which keeps the diversity of colony. The experiment demonstrates that the algorithm is better than standard genetic algorithm in clustering analysis.

  • Multimedia Technology and Application
  • HE Jun; TIAN Ying-hong; HONG Zhi-liang
    Computer Engineering. 2008, 34(6): 229-23. https://doi.org/10.3969/j.issn.1000-3428.2008.06.084
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    This paper presents a high performance VLSI architecture design for H.264/AVC entropy encoding. In the design, a fast encode all-zeros block method is proposed to accelerate the encoding process. A double RAM method is designed to avoid the mistake of storage and be easy to control data as a block. A pipeline technology is proposed to erase the RAM and make the process faster. The synthesis result shows the proposed architecture can improve the performance of the CAVLC.
  • WANG Wei; WANG Zhen-song
    Computer Engineering. 2008, 34(6): 233-236. https://doi.org/10.3969/j.issn.1000-3428.2008.06.085
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To meet the urgent needs of measurement and evaluation for IPTV video quality in real-time and respond to the deficiencies of current major commercial measurement solutions, a new real-time IPTV video quality evaluation algorithm is proposed through the analysis of the main factors, which greatly impacts the video quality. This new real-time evaluation algorithm is based on the MPQM model, and the Markov model is also used to model and calculate the network packet loss rate, image complexity and video stream bit rate, and related evaluation equations are deduced for the model. Commercial test results indicate that this algorithm can accurately evaluate the IPTV video quality in real-time.
  • Engineer Application Technology and Realization
  • RONG Ya-jun; LI Jin-bing
    Computer Engineering. 2008, 34(6): 237-239. https://doi.org/10.3969/j.issn.1000-3428.2008.06.086
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    The out voltage of the inverter in an uninterruptible power supply should be kept in frequency and phase with the electric network in order to hold the smooth swapping and the voltage on the load steady. This paper designs multicycle regulative software phase locked loop based on DSP TMS320LF2407A. The implementation of both software and hardware is presented. The experimental results verify the feasibility and validity of the proposed method.
  • LIU Peng-cheng; AI Ting-hua; HU Jing-shan;
    Computer Engineering. 2008, 34(6): 240-242. https://doi.org/10.3969/j.issn.1000-3428.2008.06.087
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Scientific visualization, computer animation and virtual reality are the three focuses on study of modern computer graphics, and 3D realistic image rendering is the core of the three focuses. The detail modeling of tunnel structure attached establishment is presented and how the technique of OpenGL, including modeling, lighting, material, model transformation and view point transformation, is applied on visualization of tunnel is described. The simulation of tunnel is realized. Practical application shows that this approach has good adaptability.
  • ZHANG Xiao-guang; DAI Shu-wu
    Computer Engineering. 2008, 34(6): 243-245. https://doi.org/10.3969/j.issn.1000-3428.2008.06.088
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    This paper describes about spacecraft autonomy, and presents a kind of system architecture based on multi-Agent, in which the system is divided into several Agents according to its software function and hardware structure. The design and implement of system framework under Vxworks is discussed, which is generally applied in space science. In the system, the Agent not only recognizes science events, retargets the spacecraft to respond to the science events, but also cooperates with the other Agents to accomplish the complex space task. In a word, the design promotes the intelligence of system, and satisfies the strict aerospace application.
  • YUAN Ming-hai; LI Dong-bo; WEI Yun
    Computer Engineering. 2008, 34(6): 246-248. https://doi.org/10.3969/j.issn.1000-3428.2008.06.089
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Considering the insufficiency of Manufacturing Execution System(MES), on the basis of the theory of reconfigurable manufacturing pattern, the architecture of reconfigurable assembly line manufacturing execution system based on CORBA and multi-Agent is presented. The reconfiguration and integration of MES can be implemented with this architecture. The system functional modules with IDEF0 are given and introduced in detail. Furthermore, the structure of the system Agent model is designed and the method for assembly resource clustering is researched. The system is used to the enterprise which is reconfigurable and extensible. The results illustrate benefits gained from the system.
  • JIA Zhi-xin; WANG Zhi-yong; HUANG Ming-ji
    Computer Engineering. 2008, 34(6): 249-251. https://doi.org/10.3969/j.issn.1000-3428.2008.06.090
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    Aiming at improving the Wire Electrical Discharge Machine(WEDM), this paper presents the integration of CAD/CAM technique applicable to WEDM. Visual C++6.0 language is used in the program. The system architecture is introduced, and the key techniques in the process of automatic programming such as automatic path planning, automatic direction judgement, and automatic compensation of cutter path are dealt within this paper. This system adopts the distributed control technique, taking PC as the host, controlling many wire electrical discharge machining tools at the same time, carrying out automatic program. Through the experiment, the operation is simple and convenient. These techniques prove effective in real machining.
  • YU Bo; HE Wei; WANG Ping; LI Xue-fei
    Computer Engineering. 2008, 34(6): 252-254. https://doi.org/10.3969/j.issn.1000-3428.2008.06.091
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    A tele-monitoring system based on embedded computer is presented. The system is based on theories and measurements about vital bio-signals, such as cardiograph, blood pressure, oxygenation of the blood, respiration and body temperature, using embedded computer as baseplate. The system can tele-monitor five vital bio-signals, such as cardiograph, blood pressure, oxygenation of the blood, respiration and body temperature, and patient’s online video through GPRS or Internet.
  • FAN Zhao-bin; SHI Zhong-ke; YANG Jun
    Computer Engineering. 2008, 34(6): 255-257. https://doi.org/10.3969/j.issn.1000-3428.2008.06.092
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    A video-based embedded vehicle detection system is presented. The scheduling of image collection is controled by FPGA and image is processed by DSP. In this system, the alternative background update method is used and the moving objects detection method is improved. It is applied to obtain traffic data for urban traffic signal control machine, and has better performances on function and maintenance compared with traditional detection methods such as inductance coil detection.
  • ZHOU Xiao-qing; QI Cong-qian; TANG Lin-xin
    Computer Engineering. 2008, 34(6): 258-260. https://doi.org/10.3969/j.issn.1000-3428.2008.06.093
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Conducted by theory of similarity, apply the idea of similarity system to analyze similarity, similarity units and similarity degree at multi-levels between different NC systems. According to partitioning principles of similarity units, define the similarity units in all-levels and quantify their eigenvalues and attribute values. Set up the mathematical model to compute the similarity degree of NC instructions. Define the deterministic similitude and fuzzy similitude of NC instructions. Study out the descriptive procedure of program format and the encoded mode of NC code. Accordingly, bring forward a kind of NC code translation system model and emphatically discuss the idea of code translation algorithm.
  • Developmental Research
  • WAN Bo; ZHANG Da-pu
    Computer Engineering. 2008, 34(6): 261-262. https://doi.org/10.3969/j.issn.1000-3428.2008.06.094
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    A linear camera calibration method with vanishing point and the invariance of cross-ratio is proposed. It needn’t know metric measurement on the model plane and the correspondences between points on the model plane and image, and it can be done fully automatically. Experimental results show that the new technique is robust and accurate.
  • LIU Rang-guo; ; PU Bao-ming; DU Sheng-dong; WANG Shou-neng
    Computer Engineering. 2008, 34(6): 263-265. https://doi.org/10.3969/j.issn.1000-3428.2008.06.095
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Regarding the mass spatial database of the satellite remote sensing image analysis system as the background, and taking the practicability and high availability as the goal, the paper explains the design and implementation of the system storage architecture, introduces the design of database optimization and the strategies of database backup, recovery, implements the scheme of disaster tolerance by using Data Guard loose connection technology of stepping the region, and also analyzes the future development of this system.
  • SUN Xiao-zhui; SHANGGUAN You-li; WEN Fu-an
    Computer Engineering. 2008, 34(6): 266-267. https://doi.org/10.3969/j.issn.1000-3428.2008.06.096
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Considering the limitation of the domestic existing network teaching system, and by analysising lightweight J2EE framework, the Web layer, business logic layer and data persistence laye are separated, while Spring, Hibernate and Struts are integrated and extended to develop a network teaching system based on domestic foundation software and hardware (Linux + NC).

  • CHAI Dong-yan; HOU Zi-feng;
    Computer Engineering. 2008, 34(6): 268-270. https://doi.org/10.3969/j.issn.1000-3428.2008.06.097
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    When developing new generation portable devices such as advanced mobile terminal and personal digital assistant, the traditional serial port and Ethernet interface are not suitable for downloading larger files. A novel method using USB to download files in Bootloader is proposed. For TI H2 evaluation board and the self-designed mobile terminal, this paper develops the USB download function, which can be used in developing and production phases for system software download and upgrade.
  • SU Hua-long; LU Song-nian
    Computer Engineering. 2008, 34(6): 271-272. https://doi.org/10.3969/j.issn.1000-3428.2008.06.098
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    With flash memory capacity growing quickly, many serious problems and founel in JFFS2, such as mount time too long and bad scalability. JFFS3 keeps the index information in flash not in RAM, and uses B+ tree to organize the file system. The paper gives a simple implementation that is based on JFFS3’s idea and area management idea.
  • ZHANG Wei-min; ZHOU Bo-sheng; LUO Wen-jie
    Computer Engineering. 2008, 34(6): 273-275. https://doi.org/10.3969/j.issn.1000-3428.2008.06.099
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An extended analytic model of sequential iterative processes is proposed. The rework impact factors included in this model take into account the impact of iteration on the task duration and the remaining time of the task at the same time. An Extended form of Design Structure Matrix(EDSM) is introduced. The EDSM can describe the model. An analytic method for calculating the expected duration of the extended sequential iterative process is presented on the condition of assuming that the model parameters are deterministic. This method is illustrated by an application involving the calculation of the expected duration of software development processes.
  • HAO Dong-bai; YAN Feng; HUANG Hao;
    Computer Engineering. 2008, 34(6): 276-278. https://doi.org/10.3969/j.issn.1000-3428.2008.06.100
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Against the leakiness means of confidential computer, a confidential computer monitor and audit system is established, by using the technology of driver filter, SPI, message broadcast interrupt, virtual printing monitor and hook on Windows platform, key algorithms and implementation methods of this system are focused. Experimental result and practice validate the availability of this system.
  • LIU Jing
    Computer Engineering. 2008, 34(6): 279-280. https://doi.org/10.3969/j.issn.1000-3428.2008.06.101
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The efficiency and quality of document management system development can not be guaranteed by traditional system analysis and design methods. Test-driven development methods in developing document management system can identify development requirement, avoid unnecessary design, quicken the process, and improve software quality. It introduces and analyzes the developing process application of document management system based on test-driven development.

  • LI Quan-zhong; ZHANG Jun-ben; YUE Xun; FEI Yu-kui
    Computer Engineering. 2008, 34(6): 281-282. https://doi.org/10.3969/j.issn.1000-3428.2008.06.102
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    The paper introduces the working theorem of hard disk guard, the composition structure of setup information and the features of the storage area. It points out some of the unconventional problems when using hard disk guard, and analyses the causes of the problems which lie in the attack of certain viruses and the registering operation of certain share softwares. Solutions are given for the protection of the system security.
  • DAI Qin; LIU Jian-bo; LIU Shi-bin
    Computer Engineering. 2008, 34(6): 283-封三. https://doi.org/10.3969/j.issn.1000-3428.2008.06.103
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    After analyzing the status and difficult problems in the remote sensing data sharing research area, this paper does some research work focusing on the key technology of remote sensing data sharing research area, such as meta-data sharing, standard processing level data sharing and remote sensing information sharing, which are the three aspects of remote sensing data sharing services. Moreover, this paper discusses the framework and implementation steps of remote sensing information sharing and integration of remote sensing information sharing services based on Web Services and service chain.