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20 January 2010, Volume 36 Issue 2
    

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  • YANG Xue-qing; LIU Zhong-kan;
    Computer Engineering. 2010, 36(2): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2010.02.001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In terms of the feature of trapdoor base of the RSA public-key cryptosystem, parallel kind computing model, this paper proposes a new model of DNA computing. Based on the model it presents a method on attacking RSA public-key cryptosystem. DNA molecule encodes the trapdoor base and public key. The trapdoor is sorted out by combination, separation, set, and clear and private key is computed by trapdoor. The expected bio-steps in the technique is only O(1bn)3 and volume of DNA is no more than 1 m3.
  • FAN Na; CAI Wan-dong; ZHAO Yu
    Computer Engineering. 2010, 36(2): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2010.02.002
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    This paper presents a novel method of extracting subjective relation between opinion targets and opinion-bearing words in Chinese opinion sentences. This method analyzes lexical and part of speech information in the sentence. Syntactic analyzing is adopted to achieve syntactic path information which is regerded as semantic feature. The two kinds of feature are both applied in maximum entropy model. According to this model, all subjective relations in the sentence are extracted. Experimental results show that this method is better than Baseline method in precision rate and F-measure.

  • LIU Dong; XIONG Wei; XING Wei-yan; WANG Peng; ZHANG Rui
    Computer Engineering. 2010, 36(2): 7-8. https://doi.org/10.3969/j.issn.1000-3428.2010.02.003
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    In order to sample precisely the state transition time when simulating non-Markovian system, a new sampling method named Approximate Sampling for Residual Distribution(ASRD) method is put forward, in which several uniform distributions are used to approach general residual life distributions. The approach-coefficient d is used to adjust sampling precision and efficiency. Another method named Forced Transitions(FT) based ASRD(FT-ASRD) simulation method is brought forward to simulate high-reliable non-Markovian systems. FT-ASRD uses FT strategy to get the unreliability parameter. Several examples show that, when 5≤d≤10, FT-ASRD is more efficient and has lower relative error compared with crude simulation methods.

  • LI Ting-yi; WANG Jin-lin; WANG Ling-fang
    Computer Engineering. 2010, 36(2): 9-12. https://doi.org/10.3969/j.issn.1000-3428.2010.02.004
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    Aiming at the problem of replica placement in a distributed media system to reduce the cost of transferring data among nodes, this paper proposes an heuristic replica placement algorithm——Zero2min based on global information, compared with common algorithm, its cost is reduced by 10%~36%. It further proposes a method to place the media data when the data is imported into the system. Simulation results show that its cost is less than Max2min.
  • ZHANG Xi-guang; CHEN Tao; LV Wei-zhong; YAN Bao-ping
    Computer Engineering. 2010, 36(2): 13-14. https://doi.org/10.3969/j.issn.1000-3428.2010.02.005
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    In the application of database on Web, when Large OBject(LOB) type columns exist in the result set of a database querying, it can easily result in some problems like running out of memory of server and network traffic if using the general methods to read and transfer the result set in the network. A novel algorithm——SBBR is provided to avoid those problems, it can handle the result set in chunks and the block size can be dynamically set. SBBR is implemented in the grid middleware-DAS of science data grid. Test results show it can handle the result set which includes LOB well.
  • MENG Qing-chun; LIU Yun-qing
    Computer Engineering. 2010, 36(2): 15-17. https://doi.org/10.3969/j.issn.1000-3428.2010.02.006
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    Existing algorithms adopt the method based on the reservation of the time when scheduling non-periodic tasks. This method can not fully response the non-periodic tasks. In order to solve the problem mentioned above, this paper proposes a new fault-tolerant schedule algorithm for distributed control system. It uses the method of partitioning the task set to execute different periodic task subset in different processors and to guarantee every processor has different reserved time. When the non-periodic task starts, the method can schedule it effectively. Result manifests that new method can improves the efficiency of the fault-tolerant schedule.
  • MAO Jun-jun; ZHU Liang-yan; ZHANG Xue-you; WU-tao;
    Computer Engineering. 2010, 36(2): 18-20. https://doi.org/10.3969/j.issn.1000-3428.2010.02.007
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    This paper analyses the dynamic characteristics and evolutionary principle of Hefei’s temperature over the past fifty-four years, it combine R/S analysis with wavelet transform, choosing db4 wavelet function, deconstruct and reconstruct the original data. It analyses the temperature based on multi-fractal analysis, discusses the stability, long-term memory, statistical self-similarity and multi-fractal of the temperature trend in Hefei from fractal dimension, non-periodic length of circulation, singular index, and multi-fractal spectrum. Analysis results show that the temperature change in Hefei whose level is clear has a multiple-scale structure, the fractal dimension of Janmary, August, November shows that the irregular degrees and the complexities of temperatures are higher than the others.
  • SHAN Zhi-long; LAN Li
    Computer Engineering. 2010, 36(2): 21-24. https://doi.org/10.3969/j.issn.1000-3428.2010.02.008
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    This paper discusses the antenna models, the ways of antennas transmission and receiving, and the problems using the directional antennas in Ad hoc networks. It summarizes the MAC protocols in Ad hoc networks with directional antennas, the problems and the solutions. Result shows that MAC protocols in Ad hoc networks with directional antennas can improve the system performance.
  • DUAN Shi-hui; WANG Jin-lin
    Computer Engineering. 2010, 36(2): 25-27. https://doi.org/10.3969/j.issn.1000-3428.2010.02.009
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    This paper studies search mechanism in unstructured Peer-to-Peer(P2P) network and introduces an improved algorithm based on Bloom Filter(BF). The algorithm uses BF technology to generate routing item and exchanges local routing table in limited range, which makes nodes know others’ shared information in this range. So it can realize purposive search and avoid traditional blind search. Simulation results show that the amount of message created by queries of this algorithm is one order of magnitude lower than traditional search and this algorithm can gain better recall rate.
  • ZHANG Jing-liang; ZHANG Jun-wei; ZHANG Jian-gang; XU Lu
    Computer Engineering. 2010, 36(2): 28-30. https://doi.org/10.3969/j.issn.1000-3428.2010.02.010
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    Aiming at the performance interference between metadata and data access, this paper proposes a novel mechanism in Blue Whale File System(BWFS) to isolate metadata from data both in physical storage and I/O path. The isolatI/On is realized by the resource separatI/On and I/O request dispatching. Test results show that, after metadata is separated and put in the high-performance media, the applicatI/On I/O bandwidth is increased by 2.6 times~2.8 times, while OPS is improved by 2 times~5 times.
  • SHI Xing-xi; ZHAO Chun-xia
    Computer Engineering. 2010, 36(2): 31-32. https://doi.org/10.3969/j.issn.1000-3428.2010.02.011
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    During the mobile robot Simultaneous Localization And Mapping(SLAM), the location is unknown and the environment round is also unpredictable. Aiming at these uncertain factors, the Bayes rule is as a theory foundation, the probability model of the mobile robot SLAM is founded, the realization process of the SLAM by Extended Kalman Filter(EKF) is discussed. A data association method between the laser radar and the feature map is introduced. Experimental results show this method is effective and reliable to realize SLAM.

  • Software Technology and Database
  • LIU Hao; ZOU Xue-cheng; LI Peng; LIU Ming; REN Hong-qiang
    Computer Engineering. 2010, 36(2): 33-35. https://doi.org/10.3969/j.issn.1000-3428.2010.02.012
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    Focusing on the structural characteristics of the wireless self-organization network and the requirements of wireless mobile terminal, a five-stage BootLoader design approach for mobile terminal based on Linux in wireless sensor network is derived. The approach can make starting flow of BootLoader program design more clearly. This paper analyzes configure and design methods of four key issues in BootLoader program implementation. The results show that the 5-stage BootLoader program can normally run in the self-design terminal platform.

  • YE Fu-jun
    Computer Engineering. 2010, 36(2): 36-38. https://doi.org/10.3969/j.issn.1000-3428.2010.02.013
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    Aiming at the problems that the traditional methods can not perform well on the short Web page fields, a Modified Edit Distance(MED) algorithm is proposed. In the process of encoding and calculating, the algorithm uses the position, order, and distance information, so the problem on the relevance between the corresponding query and short field can be converted to the problem on the similarity between the encoding strings. Simulation experimental results show this algorithm can significantly outperform the traditional algorithms for relevance ranking on short Web fields, especially for very short fields.
  • ZHOU Yue-ming; DU Yu-yue; LIU Wei
    Computer Engineering. 2010, 36(2): 39-41. https://doi.org/10.3969/j.issn.1000-3428.2010.02.014
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    This paper extends the structure of Petri nets. The generic controlling and managing system is improved into fault tolerance one. The system is layer modeled with Petri nets, which are basic layer, error detection layer and recover layer. Fault-tolerance is added into the system with recover fault policy and behavior tracking with state logos Petri-based layered modeling, error detection for software behavior and recovers the error. And correctness of this system is analyzed.
  • CHEN Hai-bo; DONG Jian-ming
    Computer Engineering. 2010, 36(2): 42-44. https://doi.org/10.3969/j.issn.1000-3428.2010.02.015
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    For the question that the executable tools of Model Driven Architecture(MDA) such as xUML, OCL, ASL are too emphasis on the semantic integrity to observe and understand for designer, a human-computer interaction supported meta model Visual Action Model(VAM) is proposed by reconstructing UML model element in MOF2, and an executable engine of VAM is developed, which makes the process of the model code and the process of actual implementation code very similar, so as to enhance availability of requirement validation and test in model-driven development.
  • YUAN Zhi-xiang; WANG Xiao-ping
    Computer Engineering. 2010, 36(2): 45-47. https://doi.org/10.3969/j.issn.1000-3428.2010.02.016
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    This paper analyses the load imbalance problem and the QoS-based fault-tolerant schedule algorithm in grid resource schedule, and proposes a schedule algorithm based on the priority of a task-based parameters of QoS constrained schedule strategy. The method is based on using the generalized stochastic Petri net with inhibitor arc to establish the grid schedule model and improve the Min-Min algorithm. Experimental results show that the algorithm can decrease the overall cost of time and cost, when the grid resource schedule runs an urgent task.

  • ZHENG Zhen; CAO Bao-xiang
    Computer Engineering. 2010, 36(2): 48-50. https://doi.org/10.3969/j.issn.1000-3428.2010.02.017
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    In order to achieve better resource sharing and interaction among distributed component libraries, make reusers search components in multiple component libraries more easily and improve the accuracy, this paper puts forward a distributed software component library retrieval mechanism based on P2P. The mechanism uses a mixed-layered architecture of P2P network. The super nodes can automatically refactor the query conditions. Thereby the reusers can be transparent to retrieve components in multiple libraries. The mechanism can enhance information sharing of distributed component libraries and increase the convenience and effectiveness of retrieval.
  • LI Hui; WANG Rui-bo
    Computer Engineering. 2010, 36(2): 51-52. https://doi.org/10.3969/j.issn.1000-3428.2010.02.018
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    With the increasing amount of data, paging query efficiency of database becomes an important issue to improve the access performance of database. This paper begins with the analysis of key factors which impact the speed of paging query, combining with the optimization theory of SQL statement in the optimized device and paging algorithms, and through the analysis of theoretical infers and experimental results, to point out design methods of paging query optimization. It achieves good results to imply the methods into paging framework of actual systems.
  • WANG Xiao-long; LI Ming
    Computer Engineering. 2010, 36(2): 53-55. https://doi.org/10.3969/j.issn.1000-3428.2010.02.019
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    The traditional UML metamodel of SWRL is difficult to express individuals of OWL class in antecedents of rules. To solve this problem, this paper represents an improved metamodel, using boolean operator to connect and to distinguish OWL properties and individuals of different OWL classes in a UML model of rules. A method to model rules with UML profile is represented. For a part of rules modeled by UML, the feasibility of formalizing them into description logics is proved, and a technique to realize that is represented.
  • ZHOU Bing; LI Xu-zhi
    Computer Engineering. 2010, 36(2): 56-57. https://doi.org/10.3969/j.issn.1000-3428.2010.02.020
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    This paper analyzes that different software in different missions is the traditional way in ground system of satellite. The level of software reuse is very low, only level up with code-level. A brand new plug-in structure software faced ground system of satellite is provided. This kind of software increases the efficiency of research. It can be reused in framework-level, and fast integrated to adapt different missions.
  • HUANG Hai-yu; HE Da-ke
    Computer Engineering. 2010, 36(2): 58-60. https://doi.org/10.3969/j.issn.1000-3428.2010.02.021
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    Among the task schedule algorithms, optimal bipartite matching can not be used for scheduling the DAG tasks directly, and the computing capabilities of machines and communication times used for data transfers between them are not considered in Earliest Time Path(ETF) algorithm. Considering such problems, an improved ETF task schedule algorithm based on optimal bipartite matching for heterogeneous computing environment is provided. Based on optimal bipartite matching for independent tasks and ETF algorithm, the algorithm considers not only the execution orders of the tasks and performance of the machines, but also the capabilities of communication between each machines and the results of the previous schedule results. Simulation experiments demonstrate that the algorithm can significantly improve the schedule performance in terms of schedule length and load balance.

  • SUN Ling-yu; LENG Ming; TAN Yun-lan; YU Song-nian
    Computer Engineering. 2010, 36(2): 61-63. https://doi.org/10.3969/j.issn.1000-3428.2010.02.022
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    According to the existence of feasible solutions, this paper proposes the Minimum Spanning Tree(MST) characteristic of weighted directed graph based on the criteria that the maximum in-degree of tree node is less than or equal to one. It proves the correctness of MST characteristic with the reduction to absurdity, by adjusting the path from root of spanning tree to sink of directed edge. Based on the MST characteristic, it also proposes the improved Prim algorithm, the improved Kruskal algorithm and its time complexity analysis. It gives the MST construction of the specified weighted directed graph. Experiment and analysis show that the improved Prim and Kruskal algorithm can find the MST of weighted directed graph correctly and effectively.
  • WU Xiao-qiong; XIAO De-bao; CHANG Ya-nan
    Computer Engineering. 2010, 36(2): 64-66. https://doi.org/10.3969/j.issn.1000-3428.2010.02.023
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    Simple Network Management Protocol(SNMP) can not meet the needs of network configuration management in nowadays development. Therefore, XML is used in network management to solve this problem. This paper aims to give a data conversion mode of SNMP Management Information Base(MIB) to XML format which includes compressing and categorizing SNMP MIB data reasonably, analyzing the characteristics of SMI and XML, and converting them correspondingly. Meanwhile, this proposed data conversion mode fills the Network Configuration(NETCONF) protocol data modeling limitations, and makes the implementation of NETCONF with better commonality and extensibility.
  • YANG Wang-dong; ZHU Qing; XI Sheng-feng; LI Chang-yun
    Computer Engineering. 2010, 36(2): 67-69. https://doi.org/10.3969/j.issn.1000-3428.2010.02.024
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    Aiming at the main form of data exchange and information sharing between information systems, called messaging service application increases increasingly and service information becomes more and more diverse, this paper presents a channel-oriented message service model. Based on the encapsulation of the message transmission channel, it uses a logical organizational unit of message(channel) to do the registration and management of messaging services dynamically. It can manage channel message service categories and add features such as messaging integration. Experimental results prove that it can enhance the flexibility of the message service and performance of message transmission.
  • ZHANG Yu; ZHANG Yan-song ;
    Computer Engineering. 2010, 36(2): 70-72. https://doi.org/10.3969/j.issn.1000-3428.2010.02.025
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    This paper focuses on requirements of multi-version management in What-if analysis. Multi-version update policy is presented in main-memory OLAP system with What-if analysis support based on different hypothetical update techniques which includes traditional cascade multi-version update and multi-version update based on difference value delta tuples. Delta tuple pre-merge mechanism is proposed to improve the performance of cascade hypothetical version merging procedure. Performance experiment shows that the pre-merge hypothetical update can reduce both time cost of multi-version updates and total time cost of What-if queries remarkably compared with cascade multi-version update.
  • CHAI Zhe-li; LIN Jia-qi; ZHU Jin-ping; TANG Ping;
    Computer Engineering. 2010, 36(2): 73-74. https://doi.org/10.3969/j.issn.1000-3428.2010.02.026
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    On basis of Bayes formula, a modified method about evaluation of software reliability is presented according to the probability-density function of the correctness of the software and mathematical characteristics of the number of test cases passing software obeying binomial distribution. The probability distribution function of the correctness of the software is deduced. Compared with the process evaluating software reliability by defining parameter, the modified method is more simply and has less calculated amount. The reliability of the platform of learning for Chinese study is evaluated with Matlab platform. Experimental results show this method is more practical.

  • YAO Chong-hua; JIANG Xin-hong; CHENG Ling-yu; CHENG Yong-yu
    Computer Engineering. 2010, 36(2): 75-77. https://doi.org/10.3969/j.issn.1000-3428.2010.02.027
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    Aiming at the problem of low performance issue of soft timer manager which is commonly used in high performance telecom system, a series of optimized algorithm and solution are proposed including double hash time wheel and mutex with small granularity which is inspired by lock-free theory. It decreases the theoretical complexity from O(n) to O(1). Through high load test, and analysis is made with SunStudio11’s performance analyzer, and the results show this optimized scheme can promote the system performance effectively.
  • JIN Wei-zu; ZHANG Xiao-xiang
    Computer Engineering. 2010, 36(2): 78-80. https://doi.org/10.3969/j.issn.1000-3428.2010.02.028
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    It is the most efficient way to make full utility of resources by sharing resource. But the differences among the heterogeneous IT systems and the independency of their transactions make the integration more difficult. Aiming at the problem, this paper proposes a service specification based on Service Oriented Architecture(SOA) to realize IT and business alignment and respond to the flexible business changes. Using this method can solve the scientific resource sharing problem and keep all kinds of resource Web sites heterogeneous and independent at the same time.
  • ZHOU Qing-lei; ZHANG Wen-ning; ZHAO Dong-ming; LI Xi-yan
    Computer Engineering. 2010, 36(2): 81-82. https://doi.org/10.3969/j.issn.1000-3428.2010.02.029
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    For solving the low defect detection rate of traditional class test technology based on state, the state construction approach based on functional test methods, such as equivalence partitioning and boundary analysis is given. The strategy of using W method to generate test sequences is described. Experimental result based on Mujava shows that the class test strategy has effective defect detection rate.
  • Networks and Communications
  • ZHANG Cui-ling; CHEN Zhi-gang; LIU An-feng; ZENG Zhi-weng
    Computer Engineering. 2010, 36(2): 83-86. https://doi.org/10.3969/j.issn.1000-3428.2010.02.030
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    The data and energy load of each position in Wireless Sensor Network(WSN) is analyzed. A novel nonuniform node distribution strategy is proposed, whose core is uniformly deploying working sensors which can satisfy the demand of monitoring in all the place of the network and more relay sensors in the place closer to the sink. These relay sensors just transmit data but not generate data. The setting of the optimal transmission radius is analyzed. Experimental results show this strategy can not only debase energy depletion but make the network lifetime extended.
  • WANG Xuan; CUI Li-mei; YU Ke; ZHANG Lin
    Computer Engineering. 2010, 36(2): 87-90. https://doi.org/10.3969/j.issn.1000-3428.2010.02.031
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    WiMAX technology which based on IEEE802.16 standard has become the dominant technique in broadband wireless access. IEEE802.16 standard leaves the choice of schedule and resource allocation schemes to the network operator. According to the users’ requirements and considering the channel conditions, this paper proposes an expanded WiMAX system-level simulation platform based on NS2 and gives a fair efficient schedule and resource allocation scheme. Simulation results prove that the scheme can meet the QoS requirements of different types of service flow and maximize the system through-output.

  • PIAN Zhao-bin; BAI Guang-wei; WANG Jun-yuan
    Computer Engineering. 2010, 36(2): 91-93. https://doi.org/10.3969/j.issn.1000-3428.2010.02.032
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    This paper presents Fractional Brownian Motion(FBM) model and applies it in feature analysis of multimedia communication traffic. The multimedia communication traffic under wire network and wireless network is gained through NS simulation experiment. It studies the autocorrelation coefficient, probability characteristic and abruptness of the two kinds of communication traffic. Results prove that the classical FBM model can not characterize all the nature of the multimedia communication traffic.
  • CHEN Wen-ping; ZHANG Xing-ming; ZHANG Jian-hui; WANG Bin
    Computer Engineering. 2010, 36(2): 94-96. https://doi.org/10.3969/j.issn.1000-3428.2010.02.033
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    Network congestion is easily to be caused by traditional single-next-hop routing protocol that always chooses the best path to route. Aiming at this problem, this paper proposes a multi-next-hop Route Information Protocol(RIP). The optimization route information is changed between neighborhood node and the route directed graph is constructed. The multi-next-hop route table for the nodes is established to realize loop free parallel transmission. Analysis results based on extended SSFNet show that this protocol can decrease the network congestion risk.
  • TAN Yi-hong; LIN Ya-ping; OUYANG Jing-cheng; LI Bin
    Computer Engineering. 2010, 36(2): 97-99. https://doi.org/10.3969/j.issn.1000-3428.2010.02.034
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    Super peers in super-peers network may become the network performance bottleneck and affect retrieval result global ranking. Aiming at this problem, this paper presents a parallel query and ranking mechanism. A building method for indexes such as class feature and a selection algorithm for query peers are presented to decrease the storage and computation burden of super peers and make it connect more common peers as possible in the scope of load capacity. A query and ranking method of query peers is presented to improve retrieval quality. Experimental results show that the mechanism is efficient.
  • ZHUANG Chun-mei; WANG Li-li; LU Jian-de
    Computer Engineering. 2010, 36(2): 100-101. https://doi.org/10.3969/j.issn.1000-3428.2010.02.035
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    This paper analyzes the problems existing in route caching of Dynamic Source Routing(DSR) protocol for mobile Ad hoc networking and its effects to DSR protocol performance. Aiming at the performance decrease problem of DSR protocol caused by stale routes in DSR route caching, the local connectivity management mechanism in AODV protocol are introduced into DSR protocol. It presents DSR with Stale Route Active Discover(DSR-SRAD) protocol and expatiates its design thoughts and implementation detail. DSR-SRAD, DSR and AODV are tested by network simulation software——NS2 and the results show that DSR-SRAD protocol has high packets delivery ratio, lower average end to end delay and routing control overhead.
  • WANG Chun-juan; DONG Li-li; JIA Li
    Computer Engineering. 2010, 36(2): 102-104. https://doi.org/10.3969/j.issn.1000-3428.2010.02.036
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    If uses cluster technology to build necessary servers, the utilization rate of every server system resources always has a great distance with each other. In order to solve the problem, this paper proposes an improved dynamic feedback load balance algorithm by analyzing the existing methods. The director receives performance data of every server, calculates the present load proportion of every server, and calculates the distribution proportion to distribute the users’ requests reasonably. Experimental result proves that the algorithm can improve the whole performance of the cluster system.
  • YANG Hong-zhang; YANG Ming-xi
    Computer Engineering. 2010, 36(2): 105-107. https://doi.org/10.3969/j.issn.1000-3428.2010.02.037
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    A novel Directed Diffusion(DD) routing protocol for Wireless Sensor Network(WSN) based on network coding is presented. Randomized linear network coding is used in the processes of establishing Directed Diffusion(DD) routing. The intermediate nodes performs coding on received packets, then forwards them. The number of packets transmission is reduced. The use of bandwidth is more efficient. Simulation results based on NS2 show that compared with the original DD routing protocol, the average remain energy of nodes and network throughput are both increased efficiently.
  • LIU Tao; LIN Lin; ZHOU Xian-wei; PENG Lai
    Computer Engineering. 2010, 36(2): 108-109. https://doi.org/10.3969/j.issn.1000-3428.2010.02.038
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    Aiming at the problem of multicast routing with minimum bandwidth consumption, a Label Optimization based Heuristic Algorithm(LOHA) is proposed, including labeling rule and the modified rule of adjacent relationship between nodes. It minimizes bandwidth consumption by modifying the labels of the nodes in the multicast tree. The time complexity of LOHA is O(n3). The multicast trees obtained by LOHA is compared with Breadth-First-Search(BFS) algorithm from two aspects such as the average forwarding node number and the average hop number. Experimental results show the multicast tree obtained by LOHA consumes less bandwidth.
  • LI Bing-zhi ; ZHENG Yang-ke
    Computer Engineering. 2010, 36(2): 110-112. https://doi.org/10.3969/j.issn.1000-3428.2010.02.039
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    Aiming at the increasingly development of network service and limited network resources, this paper puts forward to a solution of achieving multi-service data routing on gateway, which includes local service and forward service. According to the characteristic of local service, it overwrites a way that makes use of the attribute of Socket to achieve local service routing. This solution can increase the utilization ration of network resources, and reduce the cost of operators.
  • BAO Wei; XU Yun; HUANG Liu-sheng; XU Hong-li; FENG Wei;
    Computer Engineering. 2010, 36(2): 113-115. https://doi.org/10.3969/j.issn.1000-3428.2010.02.040
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    The existing prediction-based and clustering-based target tracking algorithms are usually calculation-complicated or communication- complicated which will greatly decrease the lifetime of the network. Considering all those shortcomings, this paper proposes a Speed Adaptive Tracking(SAT) algorithm which can adaptively schedule the sensors’ activities according to the speed of targets. Simulation results show that SAT algorithm can reduce at least 47% of active sensors in the tracking area, decrease the cost of communication and calculation and improve the network energy utilization ratio.
  • LI Jian-jun; XIONG Xuan-dong; TAN Xiao-zhen
    Computer Engineering. 2010, 36(2): 116-118. https://doi.org/10.3969/j.issn.1000-3428.2010.02.041
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    By analyzing Chord protocol, this paper proposes an improved Chord algorithm called MR-Chord(Chord Based on the Combination of Ring and Group), which is based on multi-ring. MR-Chord uses the structure combining multi-ring and group. Each node in the group records the whole routing of the group and the groups link into multi-ring with recursive algorithm. Analysis on theory and simulation results show that MR-Chord has better performance and adaptability of the system, and the routing tables have few redundancy.
  • DENG Ze-lin; FU Ming; LIU Yi-nan
    Computer Engineering. 2010, 36(2): 119-120. https://doi.org/10.3969/j.issn.1000-3428.2010.02.042
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    To discover heterogeneous network topology structure, a bottom-to-top discovery algorithm is proposed. All of the switches are put into a queue according to the count of their descendants, then it keeps determining the direct parent switch of the first element in the queue, deleting the first element until the queue is empty, the dummy nodes, such as hub, can be discovered. Test results show the algorithm can discover the network topology structure.
  • ZHOU Xue-mei; SUN Hao; LI Du-ning
    Computer Engineering. 2010, 36(2): 121-123. https://doi.org/10.3969/j.issn.1000-3428.2010.02.043
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    Each node makes its own decisions independently in wireless mobile Ad hoc networks. Consequently, fully cooperative behaviors cannot be taken for granted. To run the net perfectly, it is necessary to solve the cooperation between the nodes. On the basis of the specialization in wireless mobile Ad hoc networks, this paper views the interaction among the users’ decision for packet forwarding as two players packet forwarding game. Moreover, a protocol is proposed to make the payoff of each player optimal, and to make the networks optimal. It addresses these issues under more realistic scenarios how can distinguish a failure of packet forwarding, because of error prone communication channels, or malicious nodes, whose goal is to cause damage to other nodes.

  • Security Technology
  • LU Wen-jing; HUANG Kai-zhi; LUO Xing-guo; WANG Shan-shan
    Computer Engineering. 2010, 36(2): 124-126. https://doi.org/10.3969/j.issn.1000-3428.2010.02.044
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the network-layer authentication structure which relys on Protocol for carrying Authentication for Network Access(PANA) and Extensible Authentication Protocol(EAP), this paper adopts two ways of pre-authentication and authentication-associate certification, proposes a network-layer union authentication mechanism optimization way for reducing handover delay in heterogeneous networks. By simulating and comparing with IEEE 802.11i pre-authentication and network-layer-assisted pre-authentication, result on the proposed method demonstrates that the authentication delay of handover in heterogeneous networks is effectively decreased.
  • ZHANG Qing-gui
    Computer Engineering. 2010, 36(2): 127-129. https://doi.org/10.3969/j.issn.1000-3428.2010.02.045
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on quicksort theory, this paper presents a basic plaintext pair sieve algorithm and an improved algorithmone, and the computational complexity of improved algorithm is O(nlogn), which is less than O(n2) of the method by checking each pairs. It analyzes the computational complexity of plaintext pair sieve in impossible differential attacks on ARIA etc with the new algorithm, and proves that the computational complexity is higher remarkably than that in the key solving process for the one impossible differential attack on ARIA presented in ICISA 2008.

  • HUANG Yu-wen; LIU Chun-ying; LI Xiao-jian;
    Computer Engineering. 2010, 36(2): 130-131. https://doi.org/10.3969/j.issn.1000-3428.2010.02.046
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper describes the basic principles of buffer overflow and the current detection technology, and presents a detection model for buffer overflow vulnerability on binary executable file. The model uses static and dynamic detection technologies, and analyzes artificially the result in stain-tracking way. It gives specific reality for the detection model for buffer overflow in plug-in technology. Experimental results show effectiveness of the defection model.
  • JIANG Ming-fang; ZHU Ning-bo
    Computer Engineering. 2010, 36(2): 132-134. https://doi.org/10.3969/j.issn.1000-3428.2010.02.047
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A novel robust image watermark technology is presented by combining Block Truncation Coding(BTC) and secret sharing. The feature share of the original image constructed by BTC is combined with the watermark to generate the private share. In watermark extraction, the watermark can be retrieved by XOR operation between the private share and the feature share from the suspected image. The private share is dependent of the feature share, and it is possible to register multiple watermarks for a single host image, and the robustness of the feature share ensures the robustness of the watermark algorithm. This algorithm does not alter the host image when the private share is generated. Experimental results show high robustness of the proposed algorithm against common signal processing attacks.
  • YANG Xue-qing; LIU Zhong-kan;
    Computer Engineering. 2010, 36(2): 135-136. https://doi.org/10.3969/j.issn.1000-3428.2010.02.048
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In terms of the features of International Data Encryption Algorithm(IDEA), this paper presents an attacking method on IDEA code system, which is based on the sticker model of DNA computing. It uses known-plaintext to realize attack. All possible key and the known plaintext are encoded by DNA strands, and the desired key is sorted out by applying combination, separation, set and clear. The corresponding key is read out by gel electrophoresis. The method requires only one pair of plaintext-ciphertext and its time complexity is O(n2).
  • FENG Jing; XU Yong
    Computer Engineering. 2010, 36(2): 137-140. https://doi.org/10.3969/j.issn.1000-3428.2010.02.049
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Identity authentication and key exchange technology is the important means to ensure wireless communication security. Aiming at the demand of contactless smart card, this paper proposes a new mutual authentication key exchange protocol based on low power computing devices. The protocol is secure against replay attacks, man-in-the-middle attacks and interleaving attacks, and the security of the protocol is proved in the random oracle model. Result shows that the designed protocol is of good feasibility and needs smaller computing power.
  • WANG Ping; QIU Jin; QIU Yu-hui
    Computer Engineering. 2010, 36(2): 141-143. https://doi.org/10.3969/j.issn.1000-3428.2010.02.050
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to resolve the trust problem in open and autonomous P2P network, a trust model based on Gossip algorithm is proposed in which peers can autonomously deal with the information and identify trust belief with aging factor in P2P network. Simulation experimental result shows that the model can identify the peers’ trust with lower overhead and higher efficiency.
  • ZHU Wen-ye; ZHU Yue-fei; LIU Nan; CHEN Chen
    Computer Engineering. 2010, 36(2): 144-146. https://doi.org/10.3969/j.issn.1000-3428.2010.02.051
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Certification is important properties of security protocols, but Tree Automata based on Automatic Approximation for the Analysis of Security Protocols(TA4SP) can not detect certification of security protocols. To solove the above problem, this paper proposes a certification detection method for TA4SP. Based on the analysis of TA4SP, the method introduces the hierarchical certification, and achieves the expanding of certification for TA4SP. The method is a clear structure and easy to foamal. Examples show that the adoption of impoved method can detect certification of security protocols effectively.
  • XU Yan-gui; QIAN Huan-yan; DU Hong-jun
    Computer Engineering. 2010, 36(2): 147-149. https://doi.org/10.3969/j.issn.1000-3428.2010.02.052
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In Mbile IPv4(MIPv4) networks environment, it presents MIPv4-Worm, a new type of worm, and a method is presented to calculate contact rate of MIPv4 nodes. In MIPv4 networks, it analyzes and resarches the propagation strategy of worm. It establishes MIPv4-Worm Model(MWM), an epidemic model of MIPv4 networks worm. The model preferably shows how parameters influence propagation of worm. Simulation experiments of MIPv4-Worm propagation show the model can simulate the spread process of worm correctly in MIPv4 network, and provides a theoretical basis to take effective measures to prevent the propagation of MIPv4 worm in the large-scale.

  • ZHANG Qing-gui
    Computer Engineering. 2010, 36(2): 150-151. https://doi.org/10.3969/j.issn.1000-3428.2010.02.053
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper analyzes the computational complexity of the algorithm for computing the XOR differential probability of addition modulo 2n. With the idea of time-memory trade-off, by computing and storing the products of matrices algorithm in advance, and replacing the computing of matrices products with looking up tables, it improves the computing algorithm. The computational complexity of new algorithm is less than 7.7% times of that of the existing method.

  • FENG Bo; GUO Fan; YU Min
    Computer Engineering. 2010, 36(2): 152-155. https://doi.org/10.3969/j.issn.1000-3428.2010.02.054
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Most of the Probability of Packet Marking(PPM) exist many problems such as the lost of marking information, the difficulties to reconstruct attack path, low accuracy and so on. Aiming this problem, this paper presents an IP traceback method based on Dynamic Probabilistic Packet Marking(DPPM), to further improve the effectiveness of PPM. Instead of using a fixed marking probability, this paper proposes to judge whether the packet has been marked or not then choose a proper marking probability. Experimental result shows that it can solve most of the problems in PPM method, reduce sample dependence and increase the accuracy.
  • CHEN Hai-bin; YANG Xiao-yuan; LIANG Zhong-yin; WU Xu-guang
    Computer Engineering. 2010, 36(2): 156-157. https://doi.org/10.3969/j.issn.1000-3428.2010.02.055
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Forward secure characteristic is effective on dealing with the key exposure problem, a forward secure proxy signature scheme based on certificateless public key cryptography is proposed. This new scheme is forward secure by updating secret key frequently. When the proxy signature secret key is stolen, the attacker can not forge the former proxy signature, and it can reduce the loss, which caused by the key exposure to a great extent. Analysis result shows that the new scheme can overcome the problem of the certificate management in the certificate-based public key cryptosystem and the inherent key escrow problem in the identity-based public key cryptosystem.
  • HAO Nian-peng; YUE Qin;
    Computer Engineering. 2010, 36(2): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2010.02.056
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In stream ciphers, k-error linear complexity is an important index of the stability in stream cipher system. The linear complexity will be influenced while the values change in some positions. Based on a binary sequence with period 2n whose first period sequence has even Hamming weight, this paper proposes the concept of 2-position error spectrum over 2n-periodic binary sequence to describe the influence of linear complexity while changing its two positions.
  • ZHANG Peng; HUANG Kai-zhi; HE Xiao-jun
    Computer Engineering. 2010, 36(2): 161-163. https://doi.org/10.3969/j.issn.1000-3428.2010.02.057
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the characteristics of uncertainty and variability in heterogeneous wireless network, this paper proposes a dynamic trust model based on entity credibility. By introducing credibility of the candidate network and credibility of the evaluating entity, malicious behaviors of the dishonest entities are restrained effectively. Time stamp makes the evaluation pay much attention to the most recent performance records. Simulation result shows that the model can accurately evaluate the trustworthiness of the network and effectively restrain the acts of slander and co-fraud.
  • CUI Guang-hai; LIU Feng; GAO Dong-mei; CHENG Xue-han
    Computer Engineering. 2010, 36(2): 164-166. https://doi.org/10.3969/j.issn.1000-3428.2010.02.058
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In the stage of threshold digital signature generation, each signer’s work is equality. So there is not a defined person in charge, when the signature arouses dissension. This paper proposes a new threshold signature scheme that overcomes the above weakness. There is one and only one signer in charge of the signature, who mobilizes the threshold signature in the origination stage. The signer should response for the possible dissension. The scheme can prevent a dishonest of signing group from changing the signing massage to another of his choice while he is cooperating with other signers to produce a threshold signature.
  • LUO Bin; GU Wei; LV Wan-li; GONG Yan-yan
    Computer Engineering. 2010, 36(2): 167-169. https://doi.org/10.3969/j.issn.1000-3428.2010.02.059
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper reduces the dimensionality of the images using Principal Component Analysis(PCA) to decrease computation, and the principal components classified by the entropy and the standard deviation are quantized separately. Additionally, the watermark image is embedded in the sub-codebook which the energy of principal components is medium for enhancing images quality. The EENNS algorithm is substitutes for full search algorithm because of falling encoding time. Experimental results show that the proposed algorithm not only improves codebook quality evidently, but also decreases codebook generation time obviously. In addition, it is robust to common image processing operations, such as JPEG compression, cropping, and rotation and so on.
  • XU Hong-yun; YANG Xin-yuan; MA Zhi; LV Xin
    Computer Engineering. 2010, 36(2): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2010.02.060
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a new three-party quantum secure direct communication protocol with authentication. The scheme uses three-particle partially entangled states and CNOT gate to encode and decode. Two users can simultaneously transmit secret message to the third party, and partially entangled states shared can be used repeatedly. In ideal channel, the protocol is secure against incoherent attack. The advantage of the scheme is that through authentication, one can confirm the client’s legitimate identity, partially entangled states are easy to prepare and store in practice, and two users can simultaneously communicate with the third party.

  • Artificial Intelligence and Recognition Technology
  • LI Jiang; SUN Li-jun
    Computer Engineering. 2010, 36(2): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2010.02.061
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a pedestrian video detection algorithm based on convex hull clipping in order to solve the problem of pedestrian crowd video detection. The algorithm uses part convex hull technology to search pedestrian outlines, clips out contour curves of pedestrians by using concave points mining technology. It gets rid of non-head curves in clipped lines depending on rules, fast ellipse detection based on least square. Experimental results indicate that this algorithm can exactly detect overlap or connected heads and exclude non-head objects, and it has fast processing speed, high practical application value.
  • WANG Tong; LI Yun-qiang
    Computer Engineering. 2010, 36(2): 176-178. https://doi.org/10.3969/j.issn.1000-3428.2010.02.062
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper analyses the schema competitive condition of a class of complete deceptive functions, gives a formula of deceptive attractor, shows the deceptive attractor’s related random order schema to its main competitive schema has competitive superiority. To complete deceptive proportion’s defect, it gives a measuring method, one order main deceptive degree by using schema competitive degree, and proves its rationality by using representative complete deceptive functions. Based on the peculiarity of schema competitive condition of complete deceptive functions, hard complete deceptive functions are defined.

  • GUO Hu-sheng; QI Hui; WANG Wen-jian
    Computer Engineering. 2010, 36(2): 181-183. https://doi.org/10.3969/j.issn.1000-3428.2010.02.064
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper presents a Granular Support Vector Machine(GSVM) learning algorithm in order to improve the performance of SVM on imbalanced datasets. The GSVM divides some granules for majority data based on granular computing theory and extracts information granules. So the data becomes balanced, then GSVM finds local support vectors from those granules. SVM learns on these LSVs together with minority data. The satisfactory generalization performance can be obtained on imbalanced data.
  • YANG Yi-zhong; XIE Guang-jun
    Computer Engineering. 2010, 36(2): 184-185. https://doi.org/10.3969/j.issn.1000-3428.2010.02.065
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to implement gate array mode placement, Genetic Algorithm(GA) is combined with Simulated Annealing(SA) algorithm. A novel GASA algorithm is proposed. The GA is served as the main flow of the new algorithm for global search, while the SA algorithm adjusts local search. In this process, excellent results are retained and simulated annealing, which strengthens capabilities of local search and avoids trapping in the local optimum. Experimental results show that, compared with traditional GA, this algorithm can promote the global search capacity effectively.
  • YUAN Bao-she; Wshour Slam
    Computer Engineering. 2010, 36(2): 186-188. https://doi.org/10.3969/j.issn.1000-3428.2010.02.066
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In view of the demand on handwriting Uyghur letter on handset, according to the limitation of handset hardware resources, the Uyghur written language character is divided into two parts. The main body stroke, the attached stroke and so on, totally 21 characteristics as the characteristic set, build the Uyghur written language character recognition data sample template storehouse. Gathers current input coordinate sequences, classifies sketchily on the stroke number, respectively extracts the main stroke characteristics and the appendix characteristics and indicates with the binarization data. Carries on the XOR operation with the binarization and the character sample in template storehouse, and takes the sample which has least 1 integer in result after operation as candidate character. An average correct recognition rate achieves 97%.

  • ZHOU Zhong-yi; ZHU Yuan-yi
    Computer Engineering. 2010, 36(2): 189-181. https://doi.org/10.3969/j.issn.1000-3428.2010.02.067
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to enhance the performance of visual tracking methods with object appearance variation, this paper proposes an visual tracking system based on incremental subspace learning. By using particle filter method based on Incremental Principal Component Analysis(IPCA), this system incrementally learns a low dimensional eigenspace representation of the tracking results to reflect appearance variation of the target object. Experiments demonstrate that the system has better performance when the target objects undergo large pose and illumination changes in some complex environments.
  • CUI Ming-yi
    Computer Engineering. 2010, 36(2): 192-193. https://doi.org/10.3969/j.issn.1000-3428.2010.02.068
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In many Genetic Algorithm(GA) codes, Float Code (FC) is super to other codes in use. This paper is about which noise and its influence on GA performance are ignored by researches in genetic operation. It takes into account which mutation plays an important role of improving GA performance. Float Code Genetic Algorithm based on Wavelet denoising Mutation(FCGAWM) is proposed. Decomposing of FC noise is proved with wavelet in theory. FC denoising mutation is implemented in it. Experimental results indicate that the method is credible in theory and is feasible in technique.
  • Graph and Image Processing
  • XIE Ming-xia; GUO Jian-zhong; CHEN Ke
    Computer Engineering. 2010, 36(2): 194-196. https://doi.org/10.3969/j.issn.1000-3428.2010.02.069
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to promote the quality of Fisher discriminant analysis, this paper uses the two-step clustering to choose training samples and meanwhile expands the dimension of training samples through nonlinear transform in order to decrease the loss of useful information hidden in the samples during the process of Fisher discriminant analysis. The rule of discriminating is gained according to the expanded training samples to classify the unlabelled pattern in images. Experimental results show the image segmentation approach based on decision rules of the paper has a higher precision comparing to Fisher discriminant analysis based on initial training samples in low dimension and seeking much more sample features. It has better image segmentation precise.

  • WANG Chun-hua; MA Guo-chao; MA Miao
    Computer Engineering. 2010, 36(2): 197-200. https://doi.org/10.3969/j.issn.1000-3428.2010.02.070
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Object information may be lost or weakened when infrared image and visible light image are fused. This paper discusses some potential reasons and proposes an image fusion algorithm for infrared image and visible light image. According to the characteristics of infrared image and visible light image, this algorithm detects and extracts infrared image object by grey correlation theory, fuses the acquired object information and the background and detail information of visible light image. Experimental results indicate that the fused image obtained by this algorithm possesses the same object as the one in the infrared image, and keeps the same detail information as the one in the visible image.
  • HAO Hao-gang; LI Yan-ling; HUANG Chun-yan
    Computer Engineering. 2010, 36(2): 201-202. https://doi.org/10.3969/j.issn.1000-3428.2010.02.071
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the generation process of blurred image aroused by the straight and level constant velocity motion, this paper constructs cost function by using constrained least square method, energy differences of edge information approximation and the Lagrange multipliers in image spacial domain to solve the restored image and deduce its solution formula gradually. The algorithm is simple, does not need too many times iterative computations or frequency transformation. Experimental results indicate that the processed image has good quality, can satisfy peoples visual demands and avoid the high frequency deranging phenomenon in the frequency domain restoration.

  • LU Liang; WU Shan-ming; DENG Shu-jun;
    Computer Engineering. 2010, 36(2): 203-205. https://doi.org/10.3969/j.issn.1000-3428.2010.02.072
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the frame of conventional JPEG2000 compression, a segment treatment compression algorithm is put forward to solve the problem of time-consuming processing of remote sensing image. In the coding channel, the scanning stage is combined with the coding stage, so the time of the coding and deciphering process is reduced. After wavelet transformations, unimportant background information of the wavelet coefficient in high frequency sub-bands is eliminated and the handling process of important information is shortened, so the transmission time which has much correlation about compression ratios and data volume can be reduced significantly. Experimental results show the time of the remote sensing image compression, transmission and reconstruction of this algorithm can be shortened without image quality reduced.

  • BAI Ying-qi; PENG Jin-ye; WANG Da-kai; XING Tian-zhang
    Computer Engineering. 2010, 36(2): 206-208. https://doi.org/10.3969/j.issn.1000-3428.2010.02.073
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes an image coding algorithm based on Absolute Minimum Lipschitz Extension(AMLE) of image level set. On the basis of existing AMLE algorithm, this algorithm saves the bound data of image level sets and uses the method of processing scale by scale to reconstruct image. Experimental results show that this algorithm achieves higher PSNR and has better vision effect than existing AMLE algorithm.

  • CHEN Jie-long; YANG Jing
    Computer Engineering. 2010, 36(2): 209-210. https://doi.org/10.3969/j.issn.1000-3428.2010.02.074
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    On basis of analyzing EZW algorithm, an improved image coding algorithm is presented. It decomposes the wavelet coefficient into two groups and codes them separately. Meanwhile, the subordinate pass is removed and the location information of significant coefficients does not need to be kept in memory. So that the times of scanning in EZW algorithm are reduced. The coding speed is much improved and the number of coding symbols are reduced. Experimental restuls show the image quality processed by this algorithm can satisfy the application requirements.
  • Multimedia Technology and Application
  • ZHANG Min; OUYANG Jian-quan; LI Ze-zhou ; LIU Wei;
    Computer Engineering. 2010, 36(2): 211-213. https://doi.org/10.3969/j.issn.1000-3428.2010.02.075
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In view of the current audio hash fingerprinting method is not sufficient to meet the real-time monitoring for specific audio(e.g. advertising), this paper presents a fast fingerprint extraction method for specific audio. It extracts the information with the most relevant perception of each frame in frequency domain and divides the information into 33 bands. It extracts the differences between the equivalent bands from adjacent frames as the fingerprint. For each frame, 32 0/1 values are computed. Compared with existing method, this method ensures the accuracy of detection and extracts fingerprint rapidly at the same time.
  • TAN Li; YANG Ming-hua;CAO Yuan-da; CHENG Bao-dong
    Computer Engineering. 2010, 36(2): 214-216. https://doi.org/10.3969/j.issn.1000-3428.2010.02.076
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to reduce the network load, energy consumption and delay in video sensor network, this paper proposes a stratification image fusion method based on dynamic attention. The region of video monitoring is divided logically according to the structural deployment of network and inter-node regional mapping. Refined optimization of local-important-region is achieved by using dynamic attention module and multi-quality image fusion is implemented. Experimental results show that the method is effective.

  • WANG Qi-wen; HUANG Dong-jun
    Computer Engineering. 2010, 36(2): 217-219. https://doi.org/10.3969/j.issn.1000-3428.2010.02.077
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Video compression standard H.264/AVC has high compression ratio, but its algorithm is complex and the coding time is long. Aiming at the intra-frame 4×4 block, this paper proposes a fast prediction algorithm based on measurement of direction prediction mode. By measuring the intra-frame prediction direction of 4×4 block, it uses the correlation between neighboring blocks and neighboring direction prediction mode to predict the intra-frame mode. Experimental results show that compared with the full searching algorithm, this algorithm can decrease the coding time by 43% and only increase the output video bit rate by 0.8% while keeping PSNR almost unchanged.
  • SUN Li-fan; PU Jie-xin
    Computer Engineering. 2010, 36(2): 220-222. https://doi.org/10.3969/j.issn.1000-3428.2010.02.078
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the inter-frame mode selection process with large calculation of H.264 video encoder, this paper proposes a fast inter-frame mode selection algorithm. According to the edge feature information and mode correlation of encoding block, the candidate mode type of current macro-block is forecasted. The best mode distribution of inter-frame encoder is counted and analyzed. Scale of all the modes is restricted by setting self-adaptive threshold for early termination to get most matching block mode. Experimental results show that the algorithm can decrease the encoding time by 51% to 68% and reduce the computational complexity of encoder while maintaining quality and coding performance of reconfiguration image.
  • Engineer Application Technology and Realization
  • WU Wei-lu; Ding Ya-fei
    Computer Engineering. 2010, 36(2): 223-224. https://doi.org/10.3969/j.issn.1000-3428.2010.02.079
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the problem of modeling and simulation of superheterodyne receiver in communication Electronic Warfare(EW) system, this paper utilizes Simulink of software bundle in Matlab to construct simulation model of superheterodyne receiver based on Simulink platform. Dynamic simulation example of the amplitude modulation signal with the frequency of 5 kHz is given, and simulation waveforms and frequency chart are given. Experimental results show that the modeling method is effective.

  • FU Xin-hua; XIAO Ming-qing; ZHOU Yue-wen; KONG Qing-chun
    Computer Engineering. 2010, 36(2): 225-228. https://doi.org/10.3969/j.issn.1000-3428.2010.02.080
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    This paper proposes a thought of Reconfigurable Test Unit Adapter(RTUA). RTUA can be configured in real-time with programmable interface to satisfy the test requirements of different UUTs or signals. A kind of matching function is presented to describe the matching degree between test point and instrument port. Matching function integrates signal properties of test point, capability parameters of instrument and instrument’s price and so on. Hardware architecture of RTUA is put forward. Control module is implemented with SOPC and can be configured with different configuration files. Software design method of RTUA is given, test and control computer realizes the configuration management of RTUA with COM.
  • HUANG Zhan-hua; YANG Ji-chun; ZHU Meng; ZHANG Yin-xin
    Computer Engineering. 2010, 36(2): 229-231. https://doi.org/10.3969/j.issn.1000-3428.2010.02.081
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For Intelligent management of car tire production line, a method of fast recognition of car tire size code which combining a drop-in handware system is presented. Tire image is preprocessed including polar transformation, bilinear interpolation stretching and Da-Jing Method to preprocess tire image, segments specifications by connective region. Outline features of size code is extracted based on statistical methods to recognize tire size code. In the drop-in handware system, TMS320C6000 DSP is applied to realize this algorithm, program can be executed quickly by using methods such as soft assembly line, parameter storage and two-buffer memory allocation technology. Experimental result shows that the system method meets the needs of fast recognition of car tire size code.
  • LI Juan
    Computer Engineering. 2010, 36(2): 232-234. https://doi.org/10.3969/j.issn.1000-3428.2010.02.082
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper studies the iron and steel enterprise coking production real-time data gathering system, in view of the process control system’s mass data, it designs a coking production real-time database system based on CART database platform, and gives the method specifically. The system uses data interface procedure gathering process control’s real-time data, realizes the data transmission and multiuser sharing through the work local area network, and realizes the production real-time data visit and the management application using the CART database platform. In the implementation process, it uses DDE, OPC, multithreading, Windows service and many kinds of technologies to guarantee the software’s timeliness.
  • LIAO Yong-hong; LI Luo; CAI Chao-xi
    Computer Engineering. 2010, 36(2): 235-237. https://doi.org/10.3969/j.issn.1000-3428.2010.02.083
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the features of current videophone technology, business operating requirements and the problems of videophone promoting, the design scheme of dual-network integration(PSTN+ADSL/IP) communication services addressing and switch is proposed, which is suitable for telecom network division and regional carriers. It is a kind of softswitch technology, which is based on the features of dual-network integration and PSTN number of business location, the strategy that the region links disseminate and PSTN lines certification. Practice proves that the switch system is secure, controllable and flexible.
  • LI Deng-jing; FAN Shou-wen
    Computer Engineering. 2010, 36(2): 238-240. https://doi.org/10.3969/j.issn.1000-3428.2010.02.084
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    Based on the idea of redundant fault-tolerance, this paper designs a dual CPU fault-tolerant controller based on Field Programmable Gate Array(FPGA). It can detect faults and resume system performance through checkpoint reload in case of failure, and control law can self- reconfigure when sensor faults occur in the system. Simulation results show that fault-tolerance and fault rectification functions can be achieved by switching the redundant CPU and reconfiguring the control law in case of system failure.

  • MAO Hong-yu; WANG Feng-gui; WANG Wen-liang; WANG Shu-shi
    Computer Engineering. 2010, 36(2): 241-243. https://doi.org/10.3969/j.issn.1000-3428.2010.02.085
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    As for status monitoring for computer-controlled instruments, a monitoring scheme for data stream based on computer serial interface is proposed, which avoids the risk form hardware monitoring by pure software technology and judges instrument status by interception and pattern matching data stream between instruments and serial interface. In order to improve the detection efficiency of data stream and reduce the occupancy rate of resources, weighted core-fitting density approximation approach is chosen instead of traditional M-core.

  • Developmental Research
  • HU Wei-fan; YANG Hui-xian; YU Hong; WEI Juan
    Computer Engineering. 2010, 36(2): 244-246. https://doi.org/10.3969/j.issn.1000-3428.2010.02.086
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    When two difficulties in calculating practical distance by longitude and latitude degree should satisfy the error range requested not only in small scope but also in large scope, the error will be enlarged nonlinearly as the longitude enlarged. This paper improves the classical Gauss projection algorithm, splits two points distance of computing crotch strap longitude, makes the longitude difference as a control variable to get the modification factor, amends the distance of linear superposition. Experimental result shows that this method can efficiently reduce errors between areas and control the error range effectively.

  • ZHAO Hao-han; HU Xiao-qin; DENG Hong-min; MA Xiao-xu
    Computer Engineering. 2010, 36(2): 247-248. https://doi.org/10.3969/j.issn.1000-3428.2010.02.087
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    Aiming at the problem of low efficiency and slow speed in file backup area, this paper proposes a remote file backup method based on files difference. Through improvement of traditional Rsync algorithm, it achieves the differences of document in calculation functions, reduces the data transmission network to ensure the transmission efficiency. Experimental results show that this method can significantly reduce network traffic and greatly enhance efficiency of backup and recovery compared with traditional file backup method.
  • XU Na; ZHANG Xiao-tong; WANG Qin; LIANG Jing
    Computer Engineering. 2010, 36(2): 249-251. https://doi.org/10.3969/j.issn.1000-3428.2010.02.088
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    Aiming at the problem that it is difficult to implement complex algorithm to hardware circuit, this paper designs a specific assembler based on macroinstruction set model. It can automatically translate assembly language composed of macroinstructions into binary code. According to structure of Macro instruction Set Computer(MISC) system, the binary code can be organized into the state machine output in the form of VHDL. Performance test proves that the assembler supports auto-translation from assembly language to hardware circuit design language, and it can improve the developing efficiency by using hardware circuit to implement complex algorithm.
  • WANG Wei; HUANG Min; SUN He
    Computer Engineering. 2010, 36(2): 252-253. https://doi.org/10.3969/j.issn.1000-3428.2010.02.089
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    This paper proposes a social Agent oriented framework of network monitor system base on the theory of social Agent. According to the idea of network monitor data and software reuse, this framework is divided into three layers monitor system abstract model, it comprises self-function layer, individual consciousness layer and social awareness layer. A Web page content access monitor software based on this framework has the advantages of quick development speed, high resource reuse rate and strong robustness.
  • MAO Li-rui; CAI Hong-ming; XU Bo-yi; JIANG Li-hong
    Computer Engineering. 2010, 36(2): 254-256. https://doi.org/10.3969/j.issn.1000-3428.2010.02.090
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    To solve the business process integration problem of enterprise information systems in heterogeneous environment, a resource-oriented framework based on Representational State Transfer(REST) for enterprise information integration platform is presented, including resource model representation approach, resource application mechanism based on workflow and platform based on the RESTful Web Service. A sample is provided to verify the feasibility and correctness of the prototype framework and the result shows that it can meet the requirement of enterprise business process integration.
  • WAN Shu-ping
    Computer Engineering. 2010, 36(2): 257-259. https://doi.org/10.3969/j.issn.1000-3428.2010.02.091
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    Due to data fusion of multi-sensor experiment on some characteristic index, applied the least absolute deviation estimation in the theory of statistic, a fusion method for multi-sensor data is brought forward from the angle of stability. Based on the adaptive weight, the object function of the method is to minimize the absolute deviation of sensor’s measurement, the fusion weights are obtained by solving the conditioned extremum problem, so the result of fusion is given. Simulation examples show that the method is not only effective, but also very robust.
  • XIANG Chui-yi; HE Yi-gang; LI Bing; FANG Ge-feng
    Computer Engineering. 2010, 36(2): 260-262. https://doi.org/10.3969/j.issn.1000-3428.2010.02.092
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    In the Radio Frequency Identification(RFID) system, to solve the problem of the data collision resulted from the data transaction between several tags and the reader at the same time, this paper improves dynamic binary system tree search algorithm based on back off thought. On the basis of Type A of ISO14443 standard, it designs and realizes with the use of Field Programmable Gate Array(FPGA), adopts the VHDL language to program. Simulation results indicate that improved algorithm has better data adoption frequency and delivery precision.
  • YANG Qing-wen; ZHENG Yi; WANG Xiao-min; LI Hui-xiang
    Computer Engineering. 2010, 36(2): 263-265. https://doi.org/10.3969/j.issn.1000-3428.2010.02.093
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    Aiming at the structure teaching problem of the rocket launcher structures, the rocket launcher virtual reality walkthrough system using virtual reality technique is put forward. The system adopts B/S structure, and the virtual scene is applied and optimized by combining 3DSMAX and Virtual Reality Modeling Language(VRML) to modeling. Navigation of the scene is realized through joining camcorder viewpoint and suspension menu. Network platform is built with ASP+Access2000. A vivid virtual reality walkthrough learning environment is constructed.
  • ZHONG Xu; WAN Jian-yi; WAN Hong-yan
    Computer Engineering. 2010, 36(2): 266-268. https://doi.org/10.3969/j.issn.1000-3428.2010.02.094
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    In order to solve the conflict between programmability and performance in grid programming, this paper presents a structured grid programming model based on skeleton. It brings the performance prediction model of the structural skeleton into the early stage of grid programming, makes use of remote evaluation mechanism for the remote transmission of structural skeleton parameters. Experimental results prove that this model overcomes the performance problems caused in traditional methods of structural skeleton program, and enhances the development efficiency and reusability of grid software.
  • ZHANG Rui; FANG Zong-de; LI Ai-min; ZHANG Jun-hui
    Computer Engineering. 2010, 36(2): 269-271. https://doi.org/10.3969/j.issn.1000-3428.2010.02.095
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    Aiming at the problem of low retrieval accuracy when single feature describes content-based 3D model, the distance feature of global description is combined with curvature feature of local description and a novel 3D model retrieval algorithm is proposed. The similarity match is identified by using the weight sum of similarity of both distance feature and curvature feature. Simulation experimental results show that, compared with the model retrieval of single shape feature, this algorithm can obtain better retrieval effect.

  • WANG Jian; HAO Yan-bin
    Computer Engineering. 2010, 36(2): 272-274. https://doi.org/10.3969/j.issn.1000-3428.2010.02.096
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    Aiming at the problem of not any uniform metadata standard to mining data, based on related metadata standards, takes the features of environmental safety data in mining industry into consideration. It uses Five Ws and One H(5W1H) method to determine metadata core element set for environmental safety data in mining industry. The framework of metadata is given based on Federal Geographic Data Committee(FGDC) metadata standard and research is done on the algorithm using model management to transform metadata described in different algorithms. Application example proves that this algorithm is in favor of the organization and management for environmental safety data in mining industry.

  • HUANG Bu-gen; LIU Jian-jun; ZHANG Xiao-nan
    Computer Engineering. 2010, 36(2): 275-276. https://doi.org/10.3969/j.issn.1000-3428.2010.02.097
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    In the NTFS file system, video monitor file is divided into a large number of very small block for storage, the entire file is formed by the index tables, the main index table is missing when the file is deleted, but other index tables exist in the extended attributes. This paper proposes a method for recovering data by the extended property according to file. This method can effectively combine many scattered fragments together and recover most of video monitor data which has already been deleted.
  • YANG Yang; YU Ming-yan; JIN Wen-yi
    Computer Engineering. 2010, 36(2): 277-278. https://doi.org/10.3969/j.issn.1000-3428.2010.02.098
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    Aiming at the defect of existing embedded debugging program can not sustain the function of dynamically setting break point, this paper presents a portable monitor debugger design. Based on a new homemade high performance central processing unit ARCAⅢ, it describes the monitor program design procedure in detail, realizes the bootloader based on ARCAⅢ platform by debugging, experimental result proves that this design has good portable performance and high practicable value.
  • ZHANG Yan-mei; CAO Huai-hu
    Computer Engineering. 2010, 36(2): 279-281. https://doi.org/10.3969/j.issn.1000-3428.2010.02.099
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    This paper proposes a two-level service placement strategy based on P2P overlay network framework. Domains are placed on the top level, and the service components of various functions are placed in each domain. The model is built aiming at the single domain placement and associate domains placement problem, and uses three kinds of algorithm to solve. Simulation result shows the associate domains placement strategy decrease the cost of multi-domain composed service.
  • ZHAN He; YANG Ri-jie; ZHOU Xu
    Computer Engineering. 2010, 36(2): 282-284. https://doi.org/10.3969/j.issn.1000-3428.2010.02.100
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    Aiming at the actual problem in aerial anti-submarine war by passive sonobuoy, this paper uses hyperbola intersection method to position, researches how to continuously track underwater target by means of passive sonobuoy, and builds corresponding mathematical model. Simulation results prove the feasibility of this tracking method, and gets the relation between the number of sonobuoys needed and velocity, course, interval of shifting state of target and position of sonobuoy.