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05 March 2009, Volume 35 Issue 5
    

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  • CHEN Xin; ZHOU Yong-jun; WAN Jian-xiong
    Computer Engineering. 2009, 35(5): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2009.05.001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper concentrates on the construction of AFDX End System(ES) and brings out a sound framework based on analysis of crucial techniques of AFDX protocol. It designs and implements Tx protocol processing algorithm and traffic shaping-scheduling algorithm of key modules in AFDX ES for address mapping and real-time mechanism. The results of simulation on Linux OS confirm that this framework can meet reliability and real-time requirements of avionics data transmission.
  • MA Tao; SHAN Hong
    Computer Engineering. 2009, 35(5): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2009.05.002
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    This paper studies the Denial of Service(DoS) attacks modeling with an on-off characteristic in mobile Ad Hoc network. In order to reflect the realistic mobile Ad Hoc network traffic in the scenarios, building method of self-similar traffic in Qualnet is discussed. DoS attacks by injected with data are simulated and analyzed under three different network traffic models. Simulation results show DoS attacks with the on-off characteristic can destroy the network nodes, reduce the network performance, and can also save the energy and undetected.
  • WANG Xian-min; NIU Rui-qing
    Computer Engineering. 2009, 35(5): 7-8,11. https://doi.org/10.3969/j.issn.1000-3428.2009.05.003
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    This paper realizes secret annotation information hiding technique for color remote sensing image, studies the chosen method of information embedding area and proposes spatial information hiding W(L) method. The experimental results show that this technique has the virtues of good transparency, large hiding amount, accurate detecting results of secret signal and low algorithm complexity. It does no influence on the applied value of the remote sensing image, and has high practicability.

  • ZHANG Zhi-gang; MA Guang-wen; YE Wei-bao; ZHANG Jun-liang
    Computer Engineering. 2009, 35(5): 9-11. https://doi.org/10.3969/j.issn.1000-3428.2009.05.004
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    Aimed at disadvantages of the normal electricity price forecasting algorithm, this paper proposes which a method based on Adaptive Dynamic Programming(ADP) that has self study and self adaptive ability. Based on the Bellman optimization theory, that is gradually interaction with the environment to seek error minimum of the actual price and the forecast price with the Agent. It can obtain the optimal solution of System Marginal Price(SMP). It uses the California electricity market price data as forecasting simulation. Compared with the conventional method, results show that fitting accuracy and MAPE are greatly improved.
  • WU Li-hui; ZHANG Jie
    Computer Engineering. 2009, 35(5): 12-14,1. https://doi.org/10.3969/j.issn.1000-3428.2009.05.005
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    In order to meet demands of electronic assembly industry Manufacturing Executed System(MES), the MES software architecture of Web service is introduced, which is based on SOA. In order to develop MES software architecture, the implementation technologies of MES software architecture with workflow are researched. The frameworks of real-time visualization, real-time dynamic scheduling, and real-time process tracking of electronic assembly shop based on workflow are proposed. And the technology framework of MES software architecture is introduced based on the Web Services technology and J2EE development platform. The application of MES on a SMT shop shows that the software has well real-time, component-based, configuration and integration performance.
  • JIANG Yue-qiu; ZHANG Wen-bo; SUN Bin; FENG Yong-xin
    Computer Engineering. 2009, 35(5): 15-18. https://doi.org/10.3969/j.issn.1000-3428.2009.05.006
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    This paper analyzes the characteristics of the satellite network and the problem of current slow-start. A slow-start algorithm is presented, which approaches the slow-start threshold gradually and provides a smooth transition between the exponential and linear growth phases. Simulation results show that this algorithm can improve the performance of TCP congestion control at the start of a TCP connection or after a retransmission timeout, and improves throughput of satellite network.
  • LI Fei; HU Wen-sheng; LIU Wei
    Computer Engineering. 2009, 35(5): 19-21,3. https://doi.org/10.3969/j.issn.1000-3428.2009.05.007
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    This paper puts forward an improvement goals for the Chord model, such as reducing query waiting time, and analyzes the existing ideas and methods to achieve these goals. It introduces the bidirectional routing mechanism into the new algorithm and takes the successors list into the consideration of the next route hop chosen mechanism. Simulation result shows the algorithm has less queries waiting time than the original algorithm.
  • Software Technology and Database
  • YU Jing; ZHAO Meng; LIU Guo-hua
    Computer Engineering. 2009, 35(5): 22-24. https://doi.org/10.3969/j.issn.1000-3428.2009.05.008
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    Skyline operator and skyline computation play an important role in many applications, such as database communication, decision support, data visualization, spatial database. This paper analyzes the existing methods, and points out some problems in progressive disposal, query efficiency and convenience of following user selection. It proposes and proves a theorem for pruning query space based on dynamic scan theorem. Based on the thought of the theorem, a 3D algorithm of dynamic cutting plane scan queries for skyline queries is proposed. It analyzes and verifies the feasibility, efficiency and veracity of the algorithm through instance and experiment.
  • XU Yi-wen; FANG Yu; CHEN Hong-zhong;
    Computer Engineering. 2009, 35(5): 25-27. https://doi.org/10.3969/j.issn.1000-3428.2009.05.009
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    Overflow page is commonly used to deal with the duplicate keys of a B+ tree index, although it is easy to implement, it introduces great space waste. This paper adopts an alternative approach to make the B+ tree explicitly support the duplicate keys by revising the index structure, and provides the basic algorithms to implement the idea. Experiment indicates that the revised B+ tree can significantly reduce the size of the index file, which broadens the application area of B+ tree.
  • ZHANG Yu; SHEN Hong
    Computer Engineering. 2009, 35(5): 28-30,3. https://doi.org/10.3969/j.issn.1000-3428.2009.05.010
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    This paper targets at aggregate queries over historical data in data stream within time intervals, and proposes a novel storage model called Multi-Bloom Filters(MBF) based on Bloom Filters(BF). It uses a global bit vector to realize high efficiency of insertion and query, combines dynamically allocated local counter vectors to store historical data over different time intervals into these counter vectors. Therefore, MBF efficiently supports to store and query historical data over data stream using multiple levels of time granularities. A method of compressing space of MBF is given under the condition that the time span is very large. Analysis shows that MBF has great flexibility and supports approximate aggregate queries over historical data within time intervals, where optimal parameters of MBF are provided in term of query accuracy.
  • YU Xing-jiang; TAO Yang
    Computer Engineering. 2009, 35(5): 31-33. https://doi.org/10.3969/j.issn.1000-3428.2009.05.011
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    It is because the resources are geographic distributed, heterogeneous and dynamic in computational grid environments that makes QoS guided scheduling a complex and challenging problem, especially when the tasks have multiple QoS needs. The economic model is applied to solve the resource allocation problem controlled by QoS in grid. Integration function is used to quantitative QoS as an object to achieve high system utilization. A classified optimization scheduling algorithm for a set of independent tasks under the limitation of time and cost is proposed which can satisfy the multi-QoS attributes effectively. The results of the simulation in virtual Grid environment show that the algorithm can well tradeoff the actual executing cost and its budget in grid economy model.
  • CHEN He-ping; HE Lu; CHEN Bin; GU Jin-guang
    Computer Engineering. 2009, 35(5): 34-36,4. https://doi.org/10.3969/j.issn.1000-3428.2009.05.012
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    In order to make use of the existing relational database to generate ontology automatically, this paper analyzes the correspondent relationship between relational database and OWL Ontology, designs a set of conversion rules and implements an Ontology generator based on relational database in VC++ environment, which converts relational database to OWL Ontology successfully and shortens the construction time of Ontology effectively. The ontology generator is verified with a concrete example.
  • YIN Shu-ming; WANG Yi-huai
    Computer Engineering. 2009, 35(5): 37-39,4. https://doi.org/10.3969/j.issn.1000-3428.2009.05.013
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    A method of multi-program in-circuit programming is presented in embedded system according to the demand of locating multi-program in the main chip, in which the key technices are adopted based on MC9S12DG128 to achieve the allocation of system resource among multi programs such as dividing technic of flash memory space, vector redirect, design of supervisory control program. The actual application in the fundamental platform of robot development for education show that the embedded system which adopts the technic of multi-program in-circuit programming runs stably and updates conveniently.
  • ZHOU Guo-jian; WU Shao-gang; LI Zu-song; SHI Gang
    Computer Engineering. 2009, 35(5): 40-43. https://doi.org/10.3969/j.issn.1000-3428.2009.05.014
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    For embedded systems with very limited memory resources, code size becomes one of the most important optimization concerns. Using the oprofile profiling tool, this paper focuses on the Four-Phase Manual Optimization(FPMO) for the software pipelining technique when running the EEMBC benchmark. Experimental result of telecom-autocorrelation shows the FPMO method gets 40.678% performance promotion by increasing 2.04% code size but the pure compiler automatic optimization trades 38.33% performance improvements by 33.35% code size expansion.
  • LIU Zhi-yong; GENG Xin-qing
    Computer Engineering. 2009, 35(5): 44-45,4. https://doi.org/10.3969/j.issn.1000-3428.2009.05.015
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    The main defect of traditional methods of FCM algorithm is sensitive to the isolated data and is to know the number of clustering in advance. A fuzzy clustering algorithm NSFCM is presented in this paper, and NSFCM agorithm is applied to text mining. This algorithm adds a weight to the membership of the data, which is to decrease the effect on the initial cluster center. This paper applies average information entropy to find the number of clusters and adopts a density function algorithm to find the initial cluster centers. The experiment shows both the precision and the efficiency of clustering NSFCM are higher than those of FCM.
  • NIE Jian-ping; HAN Ke; DONG Chao
    Computer Engineering. 2009, 35(5): 46-49. https://doi.org/10.3969/j.issn.1000-3428.2009.05.016
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    Because capture-recapture’s estimators have a general trend of underestimation, this paper puts forward a new experience-based algorithm. Based on some data of two literatures, virtual software inspections are carried out, and the performance of both original and improved estimators are compared and analyzed. Result verifies that the estimation accuracy of new estimators is better than that of the olds.
  • WANG Wei-yi; HAO Wen-ning; ZHAO Shui-ning; JIANG Wei
    Computer Engineering. 2009, 35(5): 50-52. https://doi.org/10.3969/j.issn.1000-3428.2009.05.017
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    The particularity of military training causes the outlier phenomenon of the data in this domain, and also brings special demand of the outlier detection method. Some existing representative algorithms have their localization in this domain. In general, the attributes of data object are classified as the spatial attributes, the environment attributes and the characteristic attributes. The spatial attributes categorize data objects, the environment attributes decide the neighborhood data objects field, and the characteristic attributes count the outlier score. On the bases of the improvement of relative density method, this paper proposes a new detection algorithm based on Local Relative Density Factor(LRDF), and experimental result shows that this algorithm improves the detection accuracy, efficiency and usability compared with the other existing algorithms.
  • HUANG Xin; SANG Nan
    Computer Engineering. 2009, 35(5): 53-55. https://doi.org/10.3969/j.issn.1000-3428.2009.05.018
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    Taking into account of the characteristics of DOM tree, the paper presents a new Zone tree model bases on DOM tree and recursive x-y cut algorithm, which is generated by geometric layout and illustrates its advantage over DOM tree when it is applied to information retrieval and describes a Zone tree model algorithm. This model is mainly applied to extract bibliographic data from online articles. It is better than DOM tree used by most browsers with speed and high accuracy.
  • SHI Nian-yun; ZHANG Jin-ming; CHU Xi
    Computer Engineering. 2009, 35(5): 56-58. https://doi.org/10.3969/j.issn.1000-3428.2009.05.019
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    To inspect duplicated records, the Clustering Using Representatives(CURE) algorithm is ameliorated. The definition of pre-sampling is put forward, which can find the distribution of duplicated records so as to improve exactness of random sampling in record sets. A new method of choosing representative records for a cluster is proposed, which is based on distance infection weight. With this method, representative points are selected not only according to the density of the clusters, but also according to the importance of points including some isolated points. This method can make selecting representative points suitable. Both theory and experiment show that it is an effective approach to detect the similar duplicated records.
  • XIE Shen-quan
    Computer Engineering. 2009, 35(5): 59-60,8. https://doi.org/10.3969/j.issn.1000-3428.2009.05.020
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    Algorithm by removing an element is presented in this paper, which is to calculate m-ary de Bruijn sequences by removing element of m+1-ary de Bruijn sequence. The implementing method is by means of finding the Look-up table labels of m+1-ary n stage de Bruijn sequences from m+1-ary n stage de Bruijn sequences and finding m-ary n stage Look-up table labels by ameliorating the m+1-ary n stage Look-up table labels, then generating m-ary n stage de Bruijn sequences by using the relative Look-up table. The algorithm is effective while a de Bruijn sequence is given.
  • SHANG Shi-ju; DONG Xiang-jun; ZHAO Long
    Computer Engineering. 2009, 35(5): 61-63,9. https://doi.org/10.3969/j.issn.1000-3428.2009.05.021
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    Negative association rules can catch mutually exclusive correlations among items and play an important role in decision-making. The current mining algorithm is mainly directed against mono-database, and mining negative association rules in multi-database do not arouse people’s attention. This paper elaborates on the negative association rules of the status quo, mainly mining methods and redundant positive and negative association rules pruning methods, and then expatiates the present situation and main technology of association rules in multi-database, and developments tendency of negative association rules in multi-database is forecasted.
  • HUANG Chong-ben; TAO Jian-wen;
    Computer Engineering. 2009, 35(5): 64-67,9. https://doi.org/10.3969/j.issn.1000-3428.2009.05.022
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    In allusion to the problem of current graph indexing algorithm, this paper proposes a contrasting sub graph indexing model and developes a redundancy sensitive procedure to select a small discriminative indexing feature set, which improves the indexing performance. Experimental results on real test data show that this algorithm achieves near-optimal pruning power on various containment search workloads, and confirms its obvious advantage over indices built for traditional graph search in this new scenario.
  • YAO Lu; YANG Hai-tao; WANG Zheng-hua; YANG Peng
    Computer Engineering. 2009, 35(5): 68-71,9. https://doi.org/10.3969/j.issn.1000-3428.2009.05.023
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    Due to the shortage of sync-capacity-adaption mechanism, the performance of Sync4j is unstable and even drops dramatically when syncronizing a huge set of data records. To handle this problem, this paper proposes and implements the “horizontal division” technique to control the sync load for a higher reliability, and the “resuming at the savepoints” mechanism to upgrade the efficiency of sync abort recovery. Experimental results show that, these approaches can guarantee the performance stability of data sync for major commercial DBMSs and MS SQL Server, and improve the efficiency of sync abort recovery.
  • ZHANG You-wei; LIU Xiao-chun; WANG Yong-hong
    Computer Engineering. 2009, 35(5): 72-73,1. https://doi.org/10.3969/j.issn.1000-3428.2009.05.024
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    In static disassembly, there are disassembly indirect jump and indirect call of instructions, it is difficult to find their program invoked by these instructions. This paper gives a kind of algorithm to found program flowchart, describes data structure and flow. Moreover one removal method about abnormal nodes in flowchart is expatiated. Experimental results show that the algorithm is effective.
  • Networks and Communications
  • YAN Xiu-ying; ZHOU Ya-jian; HU Zheng-ming
    Computer Engineering. 2009, 35(5): 74-75,7. https://doi.org/10.3969/j.issn.1000-3428.2009.05.025
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    With the development of network technology, remote screen monitor is used in more and more sceneries. Although there are many remote monitor systems, rarely exists ones based on Java on the Linux platform. In this paper, a method to design a real-time remote system is proposed and implemented. The frame of the system is presented, and also the key techniques are expatiated. In the network teaching system, the tutor can monitor any student’s screen at any time using this system. According to the test, the system has the expectable real-time advantage.
  • NIU Er-li; SUN Xiao-hui; CHEN Jun; WANG Jing-lin;
    Computer Engineering. 2009, 35(5): 76-78. https://doi.org/10.3969/j.issn.1000-3428.2009.05.026
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    This paper researches the interest-based community structure of Gnutella. A new measurement of interest between nodes is proposed, and community structure in Gnutella based on the new measurement is analyzed. Experimental results show that interest-based community structure exists in global Gnutella and local area of Gnutella, and the larger the area is, the stronger the community structure presents.
  • HU Sheng-bo; MENG Xin; JIANG Li-zheng; ZHAO Na
    Computer Engineering. 2009, 35(5): 79-80,1. https://doi.org/10.3969/j.issn.1000-3428.2009.05.027
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    Deep space network is a heterogeneous network and provides long-life space explorations. This enables deep space network to have the capabilities of protocol sensing and self-reconfiguration for various space missions. The deep space network is described. The data link protocol (IEEE802.3 and HDLC) framing structures are analyzed, and the sensing algorithm based on majority rule is presented. Considering the time variant channel of deep space communications, an algorithm based on weighted average using sensing state information is given. Simulation results show the algorithm proposed in this paper outperforms the algorithm based on majority rule.
  • WU Xiang-jun; YANG Zong-kai; ZENG Tian
    Computer Engineering. 2009, 35(5): 81-83. https://doi.org/10.3969/j.issn.1000-3428.2009.05.028
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    For the capability of Resilient Packet Ring(RPR) in independently building a large-size and multiple rings network is poor. What’s more, RPR can not transport the edge to edge transparent data services across the rings. This paper presents a span-ring interconnection and carrying model based on expanding the function of GMPLS’s data plane to interconnect and transport the edge to edge data services for multiple resilient packet ring. The simulation result shows that this approach can be used to achieve transparent and reliable transportation of the span-ring services in the RPR multi-ring network.
  • HAO Xiao-chen; ZHAI Ming; LIU Bin; ZHANG Zeng-ren
    Computer Engineering. 2009, 35(5): 84-86. https://doi.org/10.3969/j.issn.1000-3428.2009.05.029
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    Aiming at the problem of unbalanced load for nodes in Wireless Sensor Network(WSN), a load-balanced Topology Control(TC) algorithm is proposed, which makes nodes as data transmitting nodes and makes the distance between two nodes and residual energy of nodes as the foundation of setting up the topology. The nodes with low energy are given node degree, which balances the network load, solves the problem that the energy consumption of some nodes in network is too fast due to over load of nodes, and extends the network lifetime.
  • JING Na-na; CHENG Dong-nian; HU Yu-xiang; WANG Hao-xue
    Computer Engineering. 2009, 35(5): 87-90. https://doi.org/10.3969/j.issn.1000-3428.2009.05.030
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    In order to solve the mobile and secure problems in the existing network, an indirect communication architecture model HBIA based on HIP protocol is propsed. In HBIA, the identity info and location info is separated, and new access routers are imported as the resonance of indirect communications. Then HBIA is implemented in the test environment and the result indicates this model can support the mobility of hosts and ensure the security very well.
  • ZHANG Bo; LUO Wei-bing; JIA Fang
    Computer Engineering. 2009, 35(5): 91-93. https://doi.org/10.3969/j.issn.1000-3428.2009.05.031
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    Based on DSDV protocol, an approach of cross-layer routing design is proposed. A reasonable length and the smallest probability of re-routing has been chosen and tested. This is a quality link mechanism which can be applied to Wireless Mesh Networks(WMN) based on IEEE802.11x. It does not require amendments of the existing MAC layer and can be added to the existing protocol as a separate module. This paper uses the cross-layer routing design to choose the routing in multi-hop networks, which can save the system expenditure and optimize system’s integrated performance.
  • TAO Yang; ZHANG Xun
    Computer Engineering. 2009, 35(5): 94-96. https://doi.org/10.3969/j.issn.1000-3428.2009.05.032
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    Based on the classical PACMAN algorithm of passive Duplicate Address Detection(DAD) algorithm, the reasons of inapplicable situations and the reasons of mis-detection are fund out. Thereby, an RPS algorithm with a few of network’s resource and node’s operational resource is proposed, markedly solves the disadvantage above and mis-deteciton. And the advantage of the RPS algorithm using the NS-2 network simulator is evaluated.
  • LIU Huan-min; WANG Hua; HU Xiang-jiang; ZHU Pei-dong
    Computer Engineering. 2009, 35(5): 97-100. https://doi.org/10.3969/j.issn.1000-3428.2009.05.033
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    Improving the ability of self-organization and interoperability is the important way to make the Internet develop well. This paper presents the notion of AS Alliance by analyzing the structure character of inter-domain routing system, which is a group of self-organized AS nodes. The security extended mechanism for inter-domain routing protocol based on AS Alliance can avoid the impact of center-control, and has lower cost of certificate management. Moreover, the stability enhanced mechanism can effectively decrease routing vibration in some extent.
  • BI Xue-jun; YANG Zhao-hong
    Computer Engineering. 2009, 35(5): 101-102. https://doi.org/10.3969/j.issn.1000-3428.2009.05.034
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    This paper proposes the parameters that can influence the data storage and index of wireless sensor networks. It applies these parameters to analyze current storage methods of wireless sensor network, and gives theoretical quantitative analysis results. According to the analysis, the typical usage scenarios of each method are introduced, which can help the design of the data management of wireless sensor networks.
  • FENG Xiu-fang; GUAN Zhi-yan; QUAN Xin-na
    Computer Engineering. 2009, 35(5): 103-105. https://doi.org/10.3969/j.issn.1000-3428.2009.05.035
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    Node coverage is one of the key techniques in Wireless Sensor Netwok(WSN). This paper presents a coverage-enhancing algorithm for non-isomorphic node network based on virtual force, which consists of computational geometry and improved virtual force algorithm. How to maximize the coverage in ideal state is studied. By using virtual potential field, nodes repel each other, which eliminates the sensing overlapping regions. Simulation experimental results show the coverage rate increases by about 20% effectively.
  • SU Jun; HU Fang-yu
    Computer Engineering. 2009, 35(5): 106-107,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.036
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    This paper analyzes the work process of SMAC protocol and the principle of adaptive listening. Aiming at the problem of useless listening existed in this mechanism, an improved scheme is proposed. By introducing the up and down nodes table into this protocol, the nodes can decide whether they are waked up by themselves, which avoids useless listening, and reduces the energy consumption. The scheme is also simulated and experimental results show this improved scheme is effective.
  • BAI Jian-dong; SUN Zhi-gang
    Computer Engineering. 2009, 35(5): 108-110,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.037
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    Aiming at the problems exixted in running process of traditional packet classification algorithm, a novel packet classification algorithm based on Bloom Filter is proposed, and the idea of which is used into the hardware medel of Intrusion Prevention System(IPS). The corresponding pretreatment engine of stream information is set up, and the method of implementation is introduced. Experimental results show this algorithm is effective and has the value of application.
  • ZHU Jian-bing; XU Wei-min
    Computer Engineering. 2009, 35(5): 111-113. https://doi.org/10.3969/j.issn.1000-3428.2009.05.038
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    In order to overcome the lack of the traditional Application-Level Multicast(ALM), this paper proposes a Peer-to-Peer(P2P)-based hybrid ALM model. This hybrid ALM model combines two different ALM network structures, such as local delivery tree and structured backbone. Each local peer group elects one coordinator according and all coordinators from local peer groups to build up the structured backbone. Coordinators are the border of local delivery trees and structured backbone. In local side, coordinators manage local peers and construct delivery trees. It constructs delivery trees on demand according to different requirements of applications and targets. In backbone side, coordinators collaborate with each others to implement the best-effort delivery. This includes two functions, one is merging route paths to reduce total hops and content replica and keep load balance over the backbone, and the other is exchanging the positions of coordinators to minimize the total delay in the backbone. In this way, the hybrid ALM model succeeds in improving the performance in scalability and collaboration.
  • CHENG Ai-hua; GE Bao-zhong; JI Zhong-heng
    Computer Engineering. 2009, 35(5): 114-116. https://doi.org/10.3969/j.issn.1000-3428.2009.05.039
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    In order to develop a new locating system in CDMA network, this paper proposes a novel TSOA/AOA locating technique, which uses the measurements of Time Sum Of Arrival(TSOA) and Angle Of Arrival(AOA) to locate a move station. It sets up the mathematical model for TSOA/AOA locating, and presents a locating and tracking algorithm based on Extended Kalman Filter(EKF). The feasibility of the algorithm is verified in the simulation.
  • WANG Yi-xin; WU Chun-qing
    Computer Engineering. 2009, 35(5): 117-118. https://doi.org/10.3969/j.issn.1000-3428.2009.05.040
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    As the progress of storage access speed is much slower than the communication transport rate, the storage bandwidth becomes the bottleneck of the router’s performance. This paper proposes a high efficient parallel storage access mechanism implemented by a simply approach combining hardware and software. Two same size output buffers are designed for alleviating the bottleneck caused by single storage interface. A paired access structure is designed by software to take use of the two same size output buffers parallely. The test results indicate that this mechanism effectively increases the router’s throughput and storage access speed.
  • WANG Xiao-lei; GUO Yun-fei; JI Jiang
    Computer Engineering. 2009, 35(5): 119-121. https://doi.org/10.3969/j.issn.1000-3428.2009.05.041
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    This paper designs a new clustering algorithm aiming at high stability in cluster structure and good performance in load balancing of cluster head. It applies the theory of vector quantization and LBG algorithm in the information theory and data compress, establishes a one by one relationship between the cluster and cell, the code vector and cluster head, the vector and node, and changes the process of clustering into the process of cell segmenting. Through the simulation, this algorithm proves that it can cluster rapidly and the structure of the cluster has high stability.
  • ZHANG Jun; LI Ying
    Computer Engineering. 2009, 35(5): 122-124. https://doi.org/10.3969/j.issn.1000-3428.2009.05.042
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    Aiming at the problems of Directional Transmit and Receive Algorithm(DTRA) such as neighbor discovery inadequacy and frequent neighbor rediscovery when the nodes density is high, or the topology of the network changes slowly, this paper puts forward an improved scheme of DTRA based on directional communication. Theoretical analysis results show this scheme can increase the probability of neighbor discovery and the data throughput of the network through the introduction of asynchrony scan frames.
  • WANG Shun-yan; SONG Guo-zheng
    Computer Engineering. 2009, 35(5): 125-127. https://doi.org/10.3969/j.issn.1000-3428.2009.05.043
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    Based on the existing network infrastructure, this paper discusses a new Web service technology——active service. This technology can make local terminal users share network resources flexibly. It is the future trend of the network service. This paper expatiates the realization mechanism of active service,which depends mainly on the applications of kinds of components. Application results show that this technology is practical.
  • YU Long; LIU Sheng-quan; TIAN Sheng-wei
    Computer Engineering. 2009, 35(5): 128-130. https://doi.org/10.3969/j.issn.1000-3428.2009.05.044
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    Based on 802.1x, this paper proposes an improved scheme for network user authentication management. The behavior of online users is controlled by the background detection server. To force the illegal users to log out is through Simple Network Management Protocol(SNMP) which drives the switch to work. This mechanism is transparent to the users, so it can strengthen the advantage of active management, and solve access control problems such as IP embezzlement and conflict, MAC lift.
  • Security Technology
  • ZHANG Xue-jun
    Computer Engineering. 2009, 35(5): 131-132,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.045
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the low efficiency problem of the existing designated verifier signatures, based on bilinear pairings and random property of extra parameter, a new efficient identity-based designated verifier signature is proposed. Under the assumption of DBH problem, security analysis in cryptography is carried out to analyze the efficiency of the scheme. Results show that the scheme’s efficiency is better than that of some existing ones under the condition of keeping all kinds of the security characteristics of designated verifier signature such as unforgeabilty and non-transferability. Its length of signature is shorter, so it is more propitious to applications in society.
  • TANG Guang-ming; WANG Bin; WANG Ya-di
    Computer Engineering. 2009, 35(5): 133-135. https://doi.org/10.3969/j.issn.1000-3428.2009.05.046
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    This paper proposes an information hiding detection evaluation based on multi-object strategy. The applied field of information hiding detection is analyzed, and to overcome the roughness of actual detection measures, the evaluation measures are extended and described. According to the different requirements of information detection applied fields, mathematic programming is exploited to choose the best one of the extended six measures such as positive detection, negative detection, false positive error, false negative error, detecting speed and applicability. Based on the requirement to each measure, the most applicable measure is selected for the application, which makes the information hiding evaluation more objective and effective.
  • FAN Zi-fu; WAN Xiao-yu
    Computer Engineering. 2009, 35(5): 136-138,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.047
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    In allusion to the problem of Session Initiation Protocol(SIP) E2E security, this paper proposes and realizes a SIP signature and encryption mechanism based on S/MIME. This security mechanism selects a new method which the function of S/MIME is migrated to SIP user Agents, to protect E2E communication user Agents SIP’s message body SDP. Simulation test results prove the high feasibility of this security mechanism, insure the integrality and nonrepudiation, and realize the expected security performance.
  • SUN Yi-xiao; ZHANG Zhuan-cheng; WANG Jia-chen; QIN Bo
    Computer Engineering. 2009, 35(5): 139-141,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.048
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    Aiming at defects which are exiting in image encryption algorithm based on chaotic sequences, this paper proposes an image chaotic encryption algorithm based on sampling without replacement. Chaotic sequences are one-to-one and high-stochastically transformed to image pixel address by using variable modular arithmetic and technique of indirect address image, realizing position scrambling and gray disturbing for image encryption. There is no strict restriction on distribution of chaotic sequences, so both parameter and initial value of chaotic sequences are as secret keys. Compared with existing similar methods, the experimental results show that this algorithm has advantages such as more superior performance, high operation speed, and easy realization.
  • YU Qing-fei; YANG Xiao-yuan; ZHOU Xuan-wu;
    Computer Engineering. 2009, 35(5): 142-143,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.049
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An Elliptic Curve Cryptography(ECC) based remote user authentication scheme using smart card is proposed, due to the fact that Hwang-Li’s scheme is vulnerable to impersonation attack. One-way function is designed based on Elliptic curve discrete logarithm problem, so that the relationship of password and identity is no longer base and power. The scheme stands up to Shen-Lin-Hwang’s attack and Chan-Chen’s attack, and makes best use of the advantages of ECC.
  • TANG Guang-ming; WANG Bin; WANG Ya-di
    Computer Engineering. 2009, 35(5): 144-146,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.050
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    This paper presents a detection method for image spatial replacement steganography based on multi-feature. By analyzing the principle of spatial replacement embedding, the commonness is found. Texture similarity and statistical relativity of bit plane are used to measure and describe the impact on the relationship of image bit planes caused by such embedding, and the randomicity of the least significant bit plane is used to measure and describe the effect that embedding has upon the bit planes’ attribute, and the detection method for spatial replacement embedding is modeled. Experiment shows that the method is of high detection accuracy and robust adaptability.
  • WANG Hui-ge; WANG Cai-fen; YI Wei; YU Hui-fang
    Computer Engineering. 2009, 35(5): 147-149. https://doi.org/10.3969/j.issn.1000-3428.2009.05.051
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    Signcryption is a scheme that combines the signature and the encryption into one. Certificateless cryptosystem realizes the properties of the certificateless, and the key-unescrow. This paper combines the signcryption and certificateless public key cryptosystem on the basis of the existing literature and realizes an improved certificateless publicly verifiable signcryption scheme. Under the random oracle model, it is provable secure against two attackers defined in the paper. The pairings in unsigncryption is less a time than that of Malone-Lee J’s ID-based scheme and the efficiency is higher.
  • ZHU Xiang-wei; XIAO Liang; WU Hui-zhong
    Computer Engineering. 2009, 35(5): 150-152. https://doi.org/10.3969/j.issn.1000-3428.2009.05.052
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    Based on Contourlet transformation knowledge foundation, the Contourlet transformation high frequency coefficients is carried on the statistical analysis. The theory and the experiment proves that the Contourlet transformation high frequency coefficient conforms to the generalized Gaussian distribution, adopting the estimation of marginal and joint statistical distribution of Contourlet coefficients via the method of maximum likelihood estimator. Embedded multiplicative watermarking and blind detection frame is presented in the Contourlet transformation domain. Experiments prove watermarking detector with a good detection performance.
  • ZHONG Xian-hai; XU Jin-fu; YAN Ying-jian
    Computer Engineering. 2009, 35(5): 153-155. https://doi.org/10.3969/j.issn.1000-3428.2009.05.053
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    With the hardware/software co-design methodology, a parallel and reconfigurable architecture of Euiptic Curve Crypto System(ECC) application specific instruction-set coprocessor is proposed, which is based on VLIW processor techniques. The coprocessor introduces parallel ECC point addition and doubling scheduling algorithms. Based on the concept of reconfiguration, the micro-architectures of function modules are designed. The whole ECC coprocessor has the characteristics of high flexibility and high processing speed. It can support scalable and parameterized Weierstrass curves over GF(p) and GF(2m)and the algorithms of signature and verification can be improved in the future. Experimental result shows that the time to process a ECC point multiplication over 192 bit-GF(p) is only 0.32 ms, which is 116%~350% faster than other similar ECC chips.
  • CHE Sheng-bing; CHE Zu-guo
    Computer Engineering. 2009, 35(5): 156-158. https://doi.org/10.3969/j.issn.1000-3428.2009.05.054
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    This paper proves invariable coefficient rule of the image in discrete cosine and wavelet transformation when it is scrambled in space domain. Based on the constructed composite chaotic iterative dynamic system, whose invariant distribution density is one, and in order to initialize composite chaotic iterative dynamic system, it puts forward two constructed functions using image scramble constant as input parameter. A fragile and adaptive image scrambling algorithm and two new scrambling evaluative parameters called similitude degree and anti-tamper radius are given. Experiments show that the algorithm can extract original image without any accessional information, and it is sensitive to all kinds of attacks. Its anti-tamper radius is larger than other scrambling algorithms, so it can be applied to the situations of strictest requests, such as law court and physic.
  • WANG Juan; GUO Yong-chong; WANG Qiang
    Computer Engineering. 2009, 35(5): 159-161,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.055
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    To alleviate the weakness of existed network covert channels in traffic concealing and proxy penetration, a new method of constructing covert channel based on BHO is proposed. The method using Internet space such as webmail, blog or bbs to transfer information. The legality and parasitic ness of BHO provides protection against anti-virus software and firewall, and make it easy to conceal traffic and penetate proxy. Detail design and code framework are given, tests are done to validate the network covert channel. Some advice are given to protect against this kind of network covert channel.
  • SHEN Lin-zhang
    Computer Engineering. 2009, 35(5): 162-164. https://doi.org/10.3969/j.issn.1000-3428.2009.05.056
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    This paper analyzes chaotic spreading sequences generated by extended chaotic map presented by Liao Ni-huan et al, and finds that the first several values of chaotic spreading sequences are not sensitive to the key. Based on the characteristic of non-sensitivity, a divide-and-conquer attack that can decrease entropy of key efficiently is proposed. When the length of key is 64 bit and the parameters d=3, h=0, the success rate of the divide-and-conquer attack is 0.979 7, and the average complexity is about 243.46. The attack can be implemented on a PC.
  • FENG Qi; WANG Zhen-yu; LI Xiang-dong; ZHOU Wu-ming
    Computer Engineering. 2009, 35(5): 165-167. https://doi.org/10.3969/j.issn.1000-3428.2009.05.057
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    Network access control technology can effectively eliminate the threats posed by the insecure endpoints. This paper describes the relevant work of the network access control technology, and according to its realization, it proposes a model of Trusted Network Connect(TNC) based on 802.1X. The authentication flow of network access and the implementation method of endpoint isolation technology are given. Experiment proves that the model ensures the trusted connection of the endpoint, and achieves isolation and remediation to the insecure endpoint.
  • XIONG Xi; GAO Fei
    Computer Engineering. 2009, 35(5): 168-170. https://doi.org/10.3969/j.issn.1000-3428.2009.05.058
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    Aiming at the uncertainty of certification path of the network-like Public Key Infrastructure(PKI) trust model, this paper brings forward a path searching algorithm for cross-certification. According to path searching servers distributed in PKI system and confidence-path maps, the algorithm searches the shortest certification path with Dijkstra algorithm. Analysis shows that, to some extent, this solution avoids the uncertainty of the certification path, and successfully accelerates the searching.
  • ZHANG Chao; HAN Ji-hong; WANG Ya-di; ZHU Yu-na; CHEN Xin-hui
    Computer Engineering. 2009, 35(5): 171-174. https://doi.org/10.3969/j.issn.1000-3428.2009.05.059
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    According to the problem that first-order logic model for security protocols can not give the understandable attack sequence, this paper introduces an improved model, which classifies the rules and unify operations, presents operation replacement rules, and develops a new system that can reconstruct attack sequence. Example with the simplified Needham-Schroeder protocol shows the effectiveness of the system.
  • XIE Zhi-qiang; GUO Jun; YANG Jing
    Computer Engineering. 2009, 35(5): 175-176,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.060
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper analyzes some defects of the traditional S/KEY One-Time Password(OTP) authorization system, and proposes a new S/KEY authorization solution. Mutual authorization between clients and the server and session key agreement is carried out, and new session key is produced in each authorization. The new S/KEY solution can effectively resist replay attacks, small integer attacks, protocol-broken attacks and personate attacks, and especially has some effects against the man-in-the-middle attacks.
  • Artificial Intelligence and Recognition Technology
  • SHAO Yan-hua; LI Jian-shi; CHEN Tian-jian; TIAN Feng; WANG Jin-rong
    Computer Engineering. 2009, 35(5): 177-179. https://doi.org/10.3969/j.issn.1000-3428.2009.05.061
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    In accordance with the limitation of traditional research on the stock market, a method of simulating the adaptability of Agent by neural network is proposed, and refer to the modeling scheme of Holland’s stock market model, an applied model of stock market using ERA scheme is built. The dynamic evolvement of the stock market under uncertain environment is simulated through the neural network approach to the self-development of consistency in Agent behavior with CT method. This scheme can aim to understand the dynamic specialty of stock market deeply.
  • SUN He-quan; PENG Qin-ke; ZHANG Quan-wei
    Computer Engineering. 2009, 35(5): 180-182. https://doi.org/10.3969/j.issn.1000-3428.2009.05.062
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    Through statistic analysis on the donor site sequences in the dataset of HS3D, the rules that the bases appear in the adjacent sites around the splice sites are used for constructing motifs, which are then utilized as the attributes of the DNA sequences. And by setting the value of each attribute the literal sequences are transformed into numeric vectors, based on which a Support Vector Machine(SVM) model is constructed to predict splice sites. The experimental results indicate that compared with the improved motif scoring model, the proposed method has diminished the influence on the prediction generated by the abnormal data effectively and also shows that the new mapping method in virtue of motifs is practicable and effectual.
  • LI Kai; HAO Li-feng
    Computer Engineering. 2009, 35(5): 183-184,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.063
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    Aiming at the stability of native Bayesian, in order to improve the performance of the Native Bayesian, and to overcome the limitation of the attributes independence assumption in the native Bayesian with ensemble, this paper presents an algorithm for building ensembles of native Bayesian classifiers on oracle selected. In this algorithm. It makes the stability of the native Bayesian with Oracle weaken, then selects the better classifier to be as the number of ensemble of the native Bayesian classifiers, and integrates the classifiers with voting method. Experimental result proves the OSBE ensemble algorithm obviously improves the accuracy of the native Bayesian. And it proves in some cases the OSBE ensemble algorithm has better classification accuracy than Bagging and Adaboost.
  • WANG Lei; ZHOU Xuan; ZHU Yan-guang; YANG Feng
    Computer Engineering. 2009, 35(5): 185-187,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.064
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    The concept of reasoning information is presented, which is used as the measure of discretization of continuous variables in Bayesian Network(BN). Genetic algorithm is used to search the best solution. Encoding method, crossover operator and mutation operator is proposed. Reasoning information is used as the function of individual fitness. Experiment proves that the Bayesian Network learning from data based on this discretization method can get more reasoning information.
  • LIU Sheng-hui; ZHANG Shu-li; WANG Bo; TENG Chun-xian
    Computer Engineering. 2009, 35(5): 188-190. https://doi.org/10.3969/j.issn.1000-3428.2009.05.065
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    A Integer Coded Partheno Genetic Algorithm(IPGA) is designed for Job-Shop Scheduling Problem(JSSP). This algorithm strengthens the unitary capability of scheduling algorithm, not only has the virtue of PGA, such as small calculation capacity, no immature convergence and so on, but also incarnates technics constraint condition in coding, such as keeping job shop scheduling sequence. Considering different sizes of FT emulation results problems show that the convergence expedites as size extends, and can give good stable solutions for solving job shop problems.
  • LIN Jian-feng; FENG Rui
    Computer Engineering. 2009, 35(5): 191-193. https://doi.org/10.3969/j.issn.1000-3428.2009.05.066
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A real time, multichannel, humanoid robot ready noise reduction method makes practical precise audio classification and speech recognition possible. Alhough scattering of sound plays an important role on humanoid robot, most conventional methods consider time delay as the only main factor for transferring model of sound propagation channel between microphones. By using characteristics of human like Head Related Transfer Function(HRTF) system, this method avoids the limitation of lackness of scattering effect. Simulations show that this method is able to improve desired sound’s SNR by 15 dB.
  • ZHANG Heng; ZOU Kai-qi; CUI Jie; ZHANG Min
    Computer Engineering. 2009, 35(5): 194-196. https://doi.org/10.3969/j.issn.1000-3428.2009.05.067
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to improve the training efficiency, an advanced Fuzzy Support Vector Machine(FSVM) algorithm based on the density clustering(DBSCAN) is proposed. The original data are pretreated through DBSCAN algorithm which is utilized to remove the center sample points that make little contribution to the classification. The remaining sets of edge sample complete the training work for FSVM to seek optimal hyper-plane. Experimental result shows that it can shorten the training time and improve the work efficiency while keeping the distribution of original sample and guaranteeing the classification precision.
  • LI Shuai; WANG Xin-jun; GAO Dan-dan
    Computer Engineering. 2009, 35(5): 197-199. https://doi.org/10.3969/j.issn.1000-3428.2009.05.068
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Clustering is one of main technical of data mining, a kind of non-teacher supervises recognition pattern. The clustering analysis concerns about the similar degree of data and rests on the specific criterion to divide the data to the different subclass. This paper unifies the Particle Swarm Optimization(PSO) algorithm, proposes a numeric clustering algorithm. In order to avoid the precocious problem which PSO algorithm possibly appears, it uses the chaos idea, simultaneously, considering each cluster’s internal similar characteristic, also introduces the spatial idea to the PSO algorithm. Experimental result indicates that the simulation algorithm has good performance in the numeric attribute cluster problems.
  • QIAN Xiao-shan
    Computer Engineering. 2009, 35(5): 200-202. https://doi.org/10.3969/j.issn.1000-3428.2009.05.069
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper introduces the basic principle of Gene Expression Programming(GEP). An improved GEP algorithm called IGEP based on dynamic mutation operator which is changed with the gene number of the genome and the number of evolutionary generation is presented. The algorithm complexity of IGEP is given in the paper. Furthermore, IGEP is applied in the solution of prediction in stock-price index. The simulation results show that the model found by IGEP is more accurate than the one of classic GEP and which proves the IGEP can be widely used in many fields.
  • Graph and Image Processing
  • WANG Shun-feng; ZHANG Jian-wei
    Computer Engineering. 2009, 35(5): 203-206,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.070
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A new anisotropic diffusion based image denoising method is proposed by analyzing the traditional important denoising models: harmonical model, Color Total Variation(CTV) model. Three requirements of image denoising are proposed. Using the structure information, the new model can anisotropic diffuse the image in the edge region and isotropic diffuse the flat region. In order to contain the corn region, the corn information is added to the new model. Experimental results show that the new denoising method is capable of sufficiently preserving geometric information such as edges and corners in addition to its effectiveness for image denoising.
  • NIE Xuan; WU Cheng-fu; CHEN Huai-min
    Computer Engineering. 2009, 35(5): 207-208,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.071
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    Conventional filtering methodologies may lead to insufficient changes of objective motion vector when it is used in noise-elimination. This paper proposes a novel noise-eliminating method in motion field based on singularity detection. It utilizes the Lip exponent to provide signal’s singularity characteristics and establish noise-vector judgment principle, which can eliminate the noise without lossing of the object. Experimental results demonstrate that it is able to eliminate noise perfectly without loss of the object.
  • ZHU Jing-fu; HUANG Feng-gang
    Computer Engineering. 2009, 35(5): 209-211,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.072
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    This paper proves the equivalency between a high-order anisotropic diffusion and wavelet shrinkage. Based on the equivalency, it puts forward the high-order anisotropic diffusion wavelet shrinkage image denoising algorithm utilizing the advantage of high-order anisotropic diffusion and wavelet shrinkage respectively. In the algorithm, it adopts the classic nonlinear diffusion method(PM) to process the low frequency part, diffuse the high frequency part using high order anisotropic diffusion to shrink the wavelet coefficient. Experimental results show that the computational complexity of high-order anisotropic diffusion wavelet shrinkage algorithm is less than the high-order anisotropic diffusion and more than wavelet shrinkage, the denoising ability is better than the two algorithms.
  • DENG Wei; ZHOU Zhu-rong; LU Lin-rui
    Computer Engineering. 2009, 35(5): 212-214. https://doi.org/10.3969/j.issn.1000-3428.2009.05.073
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    The structure of kd-tree has direct influence on the speed of ray tracing. In this paper, a new function which combines SAH to build kd-tree is designed and implemented. Different from ordinary dichotomy and original SAH, it imports ray to simplify the process of best- split-finding computation and obtains a preferable kd-tree which not only accelerates the speed but also assures the excellent effect.
  • Engineer Application Technology and Realization
  • NIU Xiao-ming; ZENG Li; LIU Bao-dong; ZOU Xiao-bing;
    Computer Engineering. 2009, 35(5): 215-217,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.074
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In Industrial Computerized Tomography(ICT), the projections may deviate due to many factors, such as shifts center of rotation, the inconsistency of the vertical height between the radial focus with the detector center, etc. The reconstructed image will be out of clarity if the practical projections are used directly. The off-center rectification for spiral cone-beam CT based on Katsevich algorithm is investigated. The excursion of the projections is transformed to the excursion of the detector center. In the process of the reconstruction, the filtering line, re-sampling, correction and back-projection are revised respectively according to the detector center excursion. Computer simulation results validate that this method can reduce negative effects of the reconstructed image caused by excursion of the projections.
  • WANG Peng; XIE Li-li; CHEN Li; GENG Heng-shan
    Computer Engineering. 2009, 35(5): 218-220. https://doi.org/10.3969/j.issn.1000-3428.2009.05.075
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    This paper introduces a temperature collect and display system on up-machine developed by Delphi. The system makes up of shortcomings that traditional drill pipe heat treatment control system can only show timely temperature and temperature changes can not be preserved. The method can provide detailed information for further analysis of drill pipe heat treatment process and ensure the quality of drill pipe. The article expounds the drill pipe heat treatment process and then explain some key issues including status changes, invalidate startup, temperature collect, temperature information store and query.
  • NIE Wen-hui; JU Shi-guang; LV Xia
    Computer Engineering. 2009, 35(5): 221-223. https://doi.org/10.3969/j.issn.1000-3428.2009.05.076
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    The traditional Supervisory Control And Data Acquisition(SCADA) systems are usually designed for closed environment, input, data and resource, which are availability known at prior and are subject to little change. There is an increasing demand for SCADA systems to be adaptive to open environments where the input data and resources are changeable. In order to adapt such trends, a kind of hierarchical resources management strategy in open SCADA system is proposed based on practices, and bandwidth allocation and CPU utilization are mainly discussed.
  • HU Qi-long; FENG Ming-fa; XIA Ji-yuan
    Computer Engineering. 2009, 35(5): 224-226,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.077
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    This article focuses on Microprocessor(MPU) as basic control and algorithm unit to replace special Digital Signal Processing(DSP) chip based on high-speed processing ability and lower cost of current MPU. And a kind of AVR, ATMEGA16L is illustrated to discuss optimized strategy of software and other attentive items during design procedure. It creates a new approach for complex control algorithm in application of communication field.
  • WANG Xin-sheng; WANG Chen-xu; FU Ming-wang
    Computer Engineering. 2009, 35(5): 227-229. https://doi.org/10.3969/j.issn.1000-3428.2009.05.078
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    This paper develops a PCI target controller and verifies it, based on study of PCI bus specification, which focuses on the whole design, data path and controlling, particularly implements FIFO interface and register interface purposing to common uses. The target controller is verified using bus function models and implemented in FPGA, which proves the design is met with functional demand and conformed to PCI v2.2 specification.
  • XIE Chuan
    Computer Engineering. 2009, 35(5): 230-232. https://doi.org/10.3969/j.issn.1000-3428.2009.05.079
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    CP2200 is a network interface chip. Its small size, simple external circuit, low cost makes it easier to design with a microcontroller interface. Based on TCP/IP protocol analysis, a concise and practical TCP/IP protocol subset with the characteristics of embedded systems and CP2200 chip is selected. This paper describes the implementation of the protocols. It provides a relatively simple and practical idea for the development of embedded network system.
  • Developmental Research
  • FENG Bing; ZHU Yuan-chang
    Computer Engineering. 2009, 35(5): 233-235. https://doi.org/10.3969/j.issn.1000-3428.2009.05.080
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    This paper presents a dispatching and resources monitoring mechanism for Web Services Resource Framework(WSRF) services based on WS-Resource factory pattern and Endpoint Reference(EPR) passing method. A Proxy Factory service is involved and substituted to create WS-Resource instance for client. In this process and the EPR passing process, on-demand dispatching and resource properties monitoring handlers are successfully inserted. It makes this mechanism more reasonable and transparent to clients or service providers and do not affect the client operations. With few or no need to recoding, most Globus Toolkit 4(GT4) WSRF services and clients that already existing can be easily integrated into this mechanism.
  • LIU Wei; LIU Lu; CHEN Luo; ZHONG Zhi-nong
    Computer Engineering. 2009, 35(5): 236-239. https://doi.org/10.3969/j.issn.1000-3428.2009.05.081
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    This paper investigates the challenging issues and technologies in managing mass remote sensing images, and gives an overview of the works and enabling technologies in the related areas. Based on the analysis, a specially designed architecture of mass remote sensing image management called D-MaRISS is proposed. The key components and core features are described. Experimental results show that the approach can effectively improve read/write performance in multiple user environment.
  • TANG Di-bin; BAI He; NI Hong; WANG Jin-lin
    Computer Engineering. 2009, 35(5): 240-242. https://doi.org/10.3969/j.issn.1000-3428.2009.05.082
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    Queue management in websites has not take into account the importance of pages. This paper proposes a Revenue Oriented Queue Management(ROQM) method, determines the trade probability of every page by analyzing the Web server logs, and ranks requests with different priorities. This method ensures that requests with high trade probability will be dropped less, thus leads to more revenue. Experiments show that ROQM will add to 59.2% of trades at most.
  • ZHANG Pu
    Computer Engineering. 2009, 35(5): 243-245. https://doi.org/10.3969/j.issn.1000-3428.2009.05.083
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    It needs a lot of programming handwork to implement foundation service such as organization management, permission management, log management, etc., when using J2EE to develop Web application. The same thing occurs when implementing a lot of page, whose structure is resemble. As a result, development work is huge and cycle of development is increased. Aiming at these problems, a Web application foundation service framework is proposed, which provides a series of foundation service module and an automated page generation tool that is used to create a lot of data page. Case indicates that by using the framework, the development efficiency will be greatly increased and the cycle of development is reduced.
  • XIE Qing-song; WEI Wei; LUO Kai; YAN Ling-bo
    Computer Engineering. 2009, 35(5): 246-248. https://doi.org/10.3969/j.issn.1000-3428.2009.05.084
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    This paper presents a two-sided linear prediction and pitch-adjusted based packet loss concealment algorithm to alleviate the speech distortion caused by lost packets in VoIP. This algorithm predicts lost packets from speech segments via either preceding, or both preceding and subsequent packets (if subsequent packet is available). Predicted samples, whose pitches are modified, are smoothed by linear weighting to obtain the final reconstructed signal which appears more reasonable in phase continuity. The assessment of resultant speech quality via objective measurement with PESQ algorithm from ITU-T P.862 shows that the algorithm significantly improves the performance.
  • SU Rui; LIN Hai-tao; WANG Xiao-ping
    Computer Engineering. 2009, 35(5): 249-250,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.085
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    As electricity market is gradually put into use, many issues must be resolved, while the regional power market simulation for solving these problems is an effective way. In this paper, a simulation think is designed against a regional electricity market. An electricity market simulation platform is set up based on High Level Architecture(HLA). The simulation system is realized using the KD-OMDT and KD-RTI. This platform can be used to research the behavior of every power network actor under power market running, provide available help on finding and solve the possible arising problems of power market running, and establishes more reasonable power market rules and protects the interest of every company and customer.
  • JING Ke; LI Lian; SU Wei; ZHAO Yan-juan
    Computer Engineering. 2009, 35(5): 251-254. https://doi.org/10.3969/j.issn.1000-3428.2009.05.086
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    This paper presents a kind of constructing method for mathematical communication environment based on MathML and Scalable Vector Graphics(SVG), and establishes MathBoard, a being developed mathematical communication platform in Lanzhou University. MathBoard supports the display and dynamic editing of mathematical formula and graphic. MathBoard is totally Web-based system, is written in MathML and SVG, and is used for posting discussion topics, questions, and responses.
  • LI Han-chun; ZHANG Bing-sen; NIE Qing-qing; SI Xue-feng; WANG Wei-juan; HAN Wei
    Computer Engineering. 2009, 35(5): 255-256,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.087
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    Computer color match with numerical analysis method is discussed in order to solve the problem of no-linearity and uncertainty in textile color dyeing process. This method establishes the mathematics model based on the mixtures of three colorants. By dong data fitting and using Newton-Krylov algorithm, the solution of dyeing recipe is realized. Experiments prove that this method shows a prospective result for color match in textile dyeing not only for its easy computing but also for its accuracy.
  • JIN Li-hua; CHEN Sheng-bo; ZHANG Xu-qing; WANG Zi-jun
    Computer Engineering. 2009, 35(5): 257-258,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.088
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    In the development process of electric power information management system, by using method combined with self-development and groupware restructuring, some technologies such as data-display with classes, double-axis plotting, and auto-draw of table data are researched, which effectively solve the problems such as uniform display of system equipment attribute information, automatic generating of quantity of electricity curve, and GPS data loading with batch of electric equipment. Experimental results show that, as the key technologies, these methods can be applied in many other electric power information management system.
  • BAO Qiang; LI Yong-ping; AO Xin-yu; ZHANG Su-ning
    Computer Engineering. 2009, 35(5): 259-261. https://doi.org/10.3969/j.issn.1000-3428.2009.05.089
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    In order to provide an easy management method of different kinds of passports, this paper proposes a design scheme for electronic passport based on Java card platform, and the functions of which are implemented according to ICAO Doc9303 standard. A universal Java card file packet i.e. Javacardfiles.jar is also designed in view of the character of Java card. The implementation process of transparent file and linear file with records is introduced. Experimental results show the electronic passport realized by this scheme runs well, and has the value of application.
  • DU Hao; YUAN Jie
    Computer Engineering. 2009, 35(5): 262-264,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.090
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    To meet modern noise assessment and management needs in airports, this paper uses such information technologies as Geographic Information System(GIS), database, and Object-oriented Programming(OOP), and integrates the analysis models of noise assessment to develop an airport noise assessment system. This system can realize such functions as noise data acquisition, storage, computing, analysis, and expression and inquiry, through series of convenient interface operations. Experimental results show this system can improve the efficiency and quality of airport noise assessment and management greatly, and provide timely and accurate decision-support information for airport planning and noise environment improvement.
  • KONG Wei-gong; ZHANG Guo-jie; ZHANG Xiao-jun
    Computer Engineering. 2009, 35(5): 265-267. https://doi.org/10.3969/j.issn.1000-3428.2009.05.091
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    This paper presents an implementation structure based on Distributed Arithmetic(DA) according to DCT character in MFCC, which optimizes DA by using ROM reduction and offset binary coder, and reduces the size of ROM table from 2N to (N/K)2K-1. The results of simulation and FPGA test show this kind of design is correct, which meets the requirement of real-time and precision in MFCC computation for speaker recognition.
  • LIU Wei-ning; ZENG Chan-juan; SUN Di-hua
    Computer Engineering. 2009, 35(5): 268-270. https://doi.org/10.3969/j.issn.1000-3428.2009.05.092
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    Aiming at the problems existed in the process of mining overspeed spots for commercial vehicles, a density-based clustering method is proposed, which searches for the spots where the overspeed usually happens in high frequency according to the GPS real-time data. The overspeed spots with high density can be found by searching in all overspeed in the neighborhood of each spot. The maximum overspeed spots can be identified by clustering. To simplify the data structure building process and reduce the memory space it occupied, the method is improved with the adjacency list replaced R*-Tree. Experimental results show this method is effective.
  • HU Yu; YANG Lin
    Computer Engineering. 2009, 35(5): 271-274. https://doi.org/10.3969/j.issn.1000-3428.2009.05.093
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    This paper presents an approach to control home appliances by Web pages. Home appliances are controlled and managed with Web gateway over Internet, which can supervise all appliances inside the home electronics network by using the customized home appliances management protocol from long distance, and distribute Web services to Internet. The main benefits of this approach are dynamic search, automatic configuration, light-weighted design and utilization of widely available TCP/IP protocol. The validity of the method is verified through a prototype system.
  • YAN Xiao-hui; HAN Yan-bo; CHENG Jing; ZHAO Zhuo-feng
    Computer Engineering. 2009, 35(5): 275-278. https://doi.org/10.3969/j.issn.1000-3428.2009.05.094
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    This paper proposes a business-oriented approach for Web services monitoring to satisfy the requirement of business management. By binding the monitoring interface with the functional interface, broker-based monitoring data collection with the uniform data model and the display of business monitoring result on mapping mechanism, the approach realizes the services monitoring systematically in three levels, such as the organization of service monitoring interface, the collection of monitoring data and the display of the result in business perspective. The implementation is given, and the application in the national science and technology information integration platform is also explained.
  • ZHU Xu-dong; ZHANG Jian
    Computer Engineering. 2009, 35(5): 278-279,. https://doi.org/10.3969/j.issn.1000-3428.2009.05.095
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    When various conditions in the waiting list meet the need of an event flag simultaneously, μC/OS Ⅱ offers two solutions to resolve conflicts. However both the solutions provided by μC/OS Ⅱ have serious defects when analyzed closely. In order to resolve the conflict, this paper puts forward the method of classification and comparison. It classifies event flags according to waiting types, and compares the filters of event flags to decide whether various conditions use the same event flag, thus avoids radically the conflict that various conditions in the waiting list meet the need of an event flag simultaneously. The result shows that the method of classification and comparison can completely solve the problem.
  • LI You; HE Li-yuan; HUANG Wei; YU Qiu-hua; WEI Qing-feng; LUO Qiong; ZHANG Yi
    Computer Engineering. 2009, 35(5): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2009.05.096
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    The Web-based production and management decision system is developed to solve the problems of the low efficiency of agricultural production and lacking of the research about farmer. The paper introduces the design ideas of the system, the process of establishing the optimization model by linear programming, the way of choosing the decision variables for planting-based, and the process of establishing constraint equation. Afterward it is applied in the training area, the result shows that the agricultural production efficiency is significant compared with usually scheme.
  • CAO Yuan; CHEN Tian-zhou
    Computer Engineering. 2009, 35(5): 283-封三. https://doi.org/10.3969/j.issn.1000-3428.2009.05.097
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    This paper introduces a technology of using NE Simulator in the pressure test of TD-SCDNA Operation Maintenance Center(OMC) system. Because of lack of enough real NEs in OMC pressure test, it tries to solve this problem and use NE Simulators to set up test enviroment. To help testers more quickly finish OMC overload test, it uses NE Simulator instead of real NE to transfer information with OMC system. According to the experiment, NE Simulator can be successfully used in the large scale pressure test of OMC System.