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Table of Content

    01 February 2005, Volume 25 Issue 02
    Network and communications
    Hybrid integrated QoS multicast routing algorithm in IP/DWDM optical Internet
    WANG Xing-wei, LI Jia, HUANG Min
    2005, 25(02):  241-244.  DOI: 10.3724/SP.J.1087.2005.0241
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    An integrated QoS multicast routing algorithm in IP/DWDM optical Internet was discussed in this paper. Considering load balancing, given a multicast request and flexible QoS requirement, to find a QoS multicast routing tree is NP-hard. Thus, a hybrid algorithm based on simulated annealing and tabu search was introduced to construct the cost suboptimal QoS multicast routing tree, embedding the wavelength assignment procedure based on segment and wavelength graph ideas. Hence, the multicast routing and wavelength assignment was solved integratedly. Simulation results show that the proposed algorithm is both feasible and effective.

    Research on request-routing system in CDN
    HU Peng, HONG Pei-lin, LI Jin-sheng, YANG Hai-song
    2005, 25(02):  245-247.  DOI: 10.3724/SP.J.1087.2005.0245
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    After DNS-based request-routing in CDN(Content Delivery Network) was analyzed firstly, the PBR2S(Policy-Based Request Routing System) architecture with policy-based of request-routing system was proposed in this article. This system could update DNS Name Server dynamically according to the state of network, it could process flash crowd more securely. Architecture, protocol and functional module were described in detail, at last the character of the system was summarized.

    New remote network topology discovery and analysis algorithm
    NAN Yu, KOU Xiao-rui, WANG Qing-xian
    2005, 25(02):  248-251.  DOI: 10.3724/SP.J.1087.2005.0248
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    This paper analyzed the principle of collecting information of network topology with SNMP and ICMP, the faults of these means and some advice were discussed. Then, a new RT algorithm of remote network topology by synthetizing many probing techniques was presented. The algorithm not only put emphasis on the collection of network devices infomation,but also gave prominence to the analysis of these infomation. Finaly, the integrality and veracity of the result of this new network topology discovery algorithm were proved by compared the results of different way,all based on an emulating network environment.

    FARA: an architecture of reorganizing the address
    ZHANG Li, YU Zhen-wei, ZHANG Ying, HUANGFU Xin-lin
    2005, 25(02):  252-255.  DOI: 10.3724/SP.J.1087.2005.0252
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     Based upon the decoupling of end-system names from network addresses, FARA provides considerable generality, flexibility and security with a range of assurance levels by avoiding the introduction of a new global namespace. The new concept of naming and binding presents an all-important direction to new generation network architecture.

    QoS routing selected algorithm based on improved genetic algorithm
    JIN Qiong,ZHOU Shi-ji,PENG Yan-ni
    2005, 25(02):  256-258.  DOI: 10.3724/SP.J.1087.2005.0256
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    A QoS routing selected algorithm based on improved genetic algorithm was proposed. In this algorithm, the resource expenditure and load-distributed of network were optimized as object function, which includes QoS parameters such as bandwidth, hop counts, cost, delay etc. It balances load, makes good use of network resource, reduces congestion of network, and increases throughout with minimized network resource. Simulation results indicate that the algorithm is efficient and reasonable to solves multi-objective programming.

    Design and implementation of a single source application layer multicast protocol
    FANG Yi, ZHANG Wei
    2005, 25(02):  259-261.  DOI: 10.3724/SP.J.2005.0259
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    This paper proposed an application layer multicast protocol named SSALM (Single Source Application Layer Multicast). SSALM protocol adopted tree-first approach, which constructed source-specific multicast tree among group members and constructed overlay network based on the tree. Group members were able to join group and quit group independently. Besides, members were able to switch in the tree. This paper described the major algorithms and the modules of implementation of this protocol. Using this protocol can save network bandwidth effectively in the existing Internet environment.

    Design of a general architecture of live streaming servers
    LI Zheng-ming, ZHANG Zuo
    2005, 25(02):  262-264.  DOI: 10.3724/SP.J.1087.2005.0262
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     In this paper such a general architecture was presented based on Rejaie’s work on the architecture of media streaming servers, which took into consideration the functions and characteristics of live streaming servers, and incorporated the impacts of fluctuant network environment on them. In this architecture, four function modules, namely Rate Control Module, Error Control Module, Video Quality Adaptation Module and Buffer Control Module, comprise the whole server. These modules respectively perform specific tasks, and collaborate to enable the whole server systems to provide adaptive video streaming services as a whole. How they can interplay and cooperate was discussed thoroughly in this paper. This architecture presented in the paper can be flexibly configured according to specific needs of particular applications, and can be helpful to development of live streaming server systems.

    Performance analysis on improved schemes of TCPin mobile Ad Hoc networks
    CHENG Jian, HONG Pei-lin, LI Jin-sheng
    2005, 25(02):  265-269.  DOI: 10.3724/SP.J.1087.2005.0265
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    The Transmission Control Protocol (TCP) was designed for reliable fixed network, it treat package loss or delayed as network congestion. But in Mobile Ad Hoc networks, other factors such as channel error, network partition and route changes also could invoke package loss, at the moment slow-start and fast recovery property of TCP will decreased the transmission performance. In this paper, we firstly discussed several main factors which infect TCP performance in Ad Hoc networks, and then presented an overall view on some representative improved schemes of TCP in Ad Hoc networks. Finally, we had an analysis and compare on these schemes.

    Capability assurance mechanism in P2P system based on JXTA
    ZHANG Li, XU Ji
    2005, 25(02):  270-272.  DOI: 10.3724/SP.J.1087.2005.0270
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    JXTA Technology is an application platform of P2P System.As a new network computing technology,Peer-to-Peer Technology has been applied to comprehensive scopes.This paper introduced the JXTA Technology and its features,and discussed the problem about the capability assurance mechanism in P2P System based on JXTA Technology.Through research and experiments, the elementary model of the capability assurance mechanism was established and implemented.

    Design and implementation of embedded CAN-Ethernet gateway
    YANG Bo, XU Cheng
    2005, 25(02):  273-275.  DOI: 10.3724/SP.J.1087.2005.0273
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    The architecture of software and hardware of the embedded CAN-Ethernet gateway were introduced, and the principle, the designing methods and technoloques of the CAN Device Driver in uClinux were described. According to the features of the CAN protocol, data package was classified into four groups with different real-time request; the structure of multi-frame was proposed to satisfy the request of sending mass data; the data structure and the method of management for the buffer of the CAN Device Driver were designed to improve the capability of communication.

    Using Java technology to implement the SIP communication
    YANG Peng,ZHAO Bo,WANG Kun,ZHOU Li-hua
    2005, 25(02):  276-278.  DOI: 10.3724/SP.J.1087.2005.0276
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    As the session controlling protocol of application-layer, SIP has the features of simple, expansibility and dilatancibility. At the basis of simple introduction of SIP protocol, the JAIN SIP exploring construction for the fulfillment of SIP communication of SUN Co was discussed in detail. To use Java language and take JAIN SIP as the core, all kinds of communication entity basic method in the fulfillment of SIP communication were described and simple model for SIP communication was built.

    Database and data mining
    Design of a query execution method for real-time database
    LIU Yun-sheng, PENG Chu-ji, LIAO Guo-qiong
    2005, 25(02):  279-282.  DOI: 10.3724/SP.J.2005.0279
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    In this paper,we analysed the weakness of the general query execution method, point method in real-time database,and then presented a flexible one,the D/S method which contains the virtues of materialization method, stream processing method and point method.Using the new method,the demand of memory decline effectively,and the space of query optimization will be enlarged.

    Study and practice of coverage metrics for rule-base of expert system
    LI Ru1 ,ZHAO Xiao-dong1,LU Guo-ying1,CHU Cheng-yuan2
    2005, 25(02):  283-285.  DOI: 10.3724/SP.J.1087.2005.0283
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    Software testing and evaluation for rule-base of expert system is an important part for ensuring quality and reliability of expert system. Motivated by structural testing techniques based on data flow analysis, a RBEF was proposed, which showed the coupling and restriction relationship of rules. Furthermore, rule-base coverage metrics criteria and test case design methods were put forward. And finally an implemented software testing tool ESRTS based on RBEF was analyzed.

    Gravity-based clustering approach
    JIANG Sheng-yi, LI Qing-hua
    2005, 25(02):  286-288.  DOI: 10.3724/SP.J.1087.2005.0286
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    The idea of the law of gravity was introduced to clustering analysis, and a gravity-based clustering approach, named GCA, was presented in this paper. At the same time, a simple method to calculate cluster threshold was put forward. The clustering approach GCA had the nearly linear time complexity with the size of dataset and the number of attributes, which resulted in good expandability. The experimental results show that the GCA creates high quality clustering.

    Improve search efficiency using policy of active index distributing in JXTA network
    ZHAO Zong-qu, ZHUANG Lei, LI Jian-chun
    2005, 25(02):  289-290.  DOI: 10.3724/SP.J.2005.0289
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    In the JXTA 2.0 reference implementation, policy of publishing and searching index is based on the policy of index fixed distribution. The current loosely-consistent RPV(rendezvous peer view) mechanism should lead to matter of query repeatedly among rendezvous peers. Index dynamic distribution was proposed to improve performance of finding objective index; the redundancy and swing of the index were analyzed and resolved also. It can avoid walking in RPV repeatedly and decrease the distance of every walk, so can achieve a better search efficiency.

    Classification analysis of speech recognition errors
    FU Yue-wen, DU Li-min
    2005, 25(02):  291-293.  DOI: 10.3724/SP.J.1087.2005.0291
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    Large vocabulary continuous speech recognition system consists of several components, and recognition errors are caused by different factors. Developers need to know how the errors occur. In this paper we deduced the principle to classify the recognition errors from the recognition theory and put each error according to its cause into one of four classes: the decoding, the acoustic model, the language model, and the acoustic and language model. We then performed statistical analysis of classified errors. Experiments show that classification analysis of recognition errors provides guidance for improving the system.

    Design, realization and application of clustering algorithm based on the distance between grids
    TIAN Qi-ming, WANG Li-zhen,YIN Qun
    2005, 25(02):  294-296.  DOI: 10.3724/SP.J.1087.2005.0294
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    This paper presented a new clustering algorithm based on the distance between grids. The new algorithm not only overcomed the shortcoming of K-Medoid algorithm which has much difficulties to suppose K in advance, confirm the initialized points and explain realistically, but also overcomed the shortcoming of clustering algorithm based on grids which requests dense data in spaces. The new algorithm was proved to be correct and efficient by the results of experiments.

    Security analysis of data transporting in database application system with sniffer
    CHEN Xi-hua,LI Sheng-hong
    2005, 25(02):  297-300.  DOI: 10.3724/SP.J.1087.2005.0297
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    This paper first showed respective characteristics of typical database application systems and introduced the theory of sniffer technology.It put forward a new method of analyzing data transfer security numerically with sniffer technology.Then it told how to make an experiment with this method and showed results of the experiment by using this method. At last,the paper emphasized the advantage of using this method to analyze data transfer security of database application system.

    Modularization design method for Web pages based on virtual description model
    XIONG Qian, ZHU Zheng-Yu, ZHU Qing-sheng
    2005, 25(02):  301-304.  DOI: 10.3724/SP.J.1087.2005.0301
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    Refer to the idea of Modularization program design method, this paper presented a new idea of Modularization design method for the Web pages base on its virtual description model. The combination of the new model and the modularization method greatly changeed the way to organize and storage Web information. The new technique bring us many advantages on the design of Web page such as the easy reuse of a module, the quick recombination of a Web page, the easy update for the content of a Web page, the easy expanding of a Web page, etc.

    Rerank method of rearch engine
    YANG Guang-xiang, YU Ning, SHEN Li
    2005, 25(02):  305-308.  DOI: 10.3724/SP.J.1087.2005.0305
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    The result that current web search engineer returned were ranked mainly by their hyperlink analyse, not their content. To take the search results as an order collection, we used item frenqency statistic and calculated item position in every page by certain formula, by which we calculated each pages relativity and re-ranked the collection. The experiment results show that the pages which meet the users needs were concentrated ahead. In this way, The precision was enhanced. It can help user find information rapidly.

    Rerank method of rearch engine
    TAO Jun, HONG Guo-hui
    2005, 25(02):  309-311.  DOI: 10.3724/SP.J.1087.2005.0309
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    Self generating neural networks have been presented as a better alternative to fixed structure in data mining application. The paper provided the algorithm of Self Organising Map(SOM), and presented an version of Growing Self Organising Map(GSOM) model which can extend into a nearest prototype classifier, and gave an application in data mining using GSOM.

    Research on performance improvement of Web applications based on separating static and dynamic content
    ZHAO Yang, WEI Hui-qin
    2005, 25(02):  312-313.  DOI: 10.3724/SP.J.1087.2005.0312
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    According to the development of Web field, the construction of Web application based on J2EE was introduced. The popular approach of deploying the static and dynamic content on to Application Server was discussed, and the original approach of dividing files between the Web server and Application Server was researched, furthermore a new approch of performance improvement of Web application by separating static and dynamic content is advanced. Finally, using IBM HTTP Server and WebSphere Application Server, the efficiency comparison between the two approach was presented.

    Heuristic algorithm of user session identification based on ExLF Log file format
    FENG Lin, HE Ming-rui, LUO Fen
    2005, 25(02):  314-316.  DOI: 10.3724/SP.J.1087.2005.0314
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    Based on ExLF Log file format, the Session Tabel was defined, and the conception of user session graph was expounded in detail. A heuristic algorithm of creating graph of user sessions identification was presented. At last, an example illustrated the efficiency of this algorithm.

    Image processing & multi-media
    Research on multiple descriptions transform coding algorithm based on wavelet
    LIU Jie-ping, YU Ying-lin
    2005, 25(02):  317-319.  DOI: 10.3724/SP.J.2005.0317
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    A multiple descriptions transform coding algorithm based on wavelet (WMDTC) is proposed. We first partitioned the wavelet coefficients of the highest and lowest pyramid levels into two sets. A pairwise correlating transform (PCT) was applied to each pair to generate two new sets of coefficients that were correlated between the sets. Coefficients in each set were encoded and decoded independently. Each description was then transmitted through separate channels. If only one channel was working, it was possible to estimate the lost description from another. We combined WMDTC with interpolation to improve reconstructed image. The algorithm performs well in performance simulations.

    Effective method for the arbitary clip plane extraction on the three medical anatomy planes
    XU Peng ,YAO De-zhong
    2005, 25(02):  320-321.  DOI: 10.3724/SP.J.1087.2005.0320
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    Medical clip plane extraction on the three orthogonal medical planes is a key technique in the clinic diagnosis. In this paper, the complex spatial relations between these abstract planes were clearly discussed by the spatial gometroy theory. For extracted clip sections on different orthogonal planes, corresponding interpolation method was adopted to gain clip images with high quality, which could provide extra and useful image perspective for the doctors. The results confirmed the method in the paper.

    Study on image automatic registration based on layered multi-template matching
    LIU Zhen, GONG Peng, SHI Pei-jun
    2005, 25(02):  322-325.  DOI: 10.3724/SP.J.1087.2005.0322
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    In automatic registration of high resolution imagery, the main problem was how to select templates or subimages, which were noise free and had strong features that can aid in the registration, and how to reduce search data and space. This paper provided a description of the method and flow chart of an automatic and subimage selection and presented a method of gradient energy-based selection and subimage selection with more noise and dynamic objects such as cars and trees which was easier to change in different temporal image. Multi-resolution wavelet decomposition techniques and self-adaptive image matching are used to reduce search space and data. Test results with high spatial imagery show good performance.

    Local border search algorithm and its application
    WU Gui-fang, XU Ke, XU Jin-wu
    2005, 25(02):  326-328.  DOI: 10.3724/SP.J.1087.2005.0326
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    A fast border-detection algorithm named local border search algorithm was presented here, and applied to an on-line surface inspection system for cold rolled strips. Based on the last search result, a local search was used to position the cold rolled strip border and increased the algorithms speed greatly. Test with images collected from real world data shows that local border search algorithm is about 20 to 200 times faster than the traditional gray level gradient threshold algorithm, and can detect borders more accurately. The algorithm can also be used in the search of other image border.

    Study on 3D-scene rebuilding technology based on microphone
    LU Yun-ting, CHEN You-qing, LI Zhen-jun
    2005, 25(02):  329-331.  DOI: 10.3724/SP.J.1087.2005.0329
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    In this paper, a technology of 3D rebuilding based on microphones graphs was presented, which could revert 3D characters of 2D-fixed graphs. Depended on theory, 3D rebuilding could be realize by Direct3D in VC compiling environment.

    Image interpolation using wavelet transform based on statistical features
    DU Hui-qian, MEI Wen-bo, SU Guang-chuan
    2005, 25(02):  332-334.  DOI: 10.3724/SP.J.1087.2005.0332
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    This paper proposed an interpolation algorithm using wavelet transform based on statistical features for natural images. The basic idea was to estimate the high-resolution covariances from low-resolution counterpart based on their "geometric duality" so that un-sampled pixels were obtained. In addition, wavelet decomposition and reconstruction were also used to enhance image details. No iterative computation was needed in this algorithm. The application of this new interpolation algorithm shows that it can keep the contours and details of non-edged areas successfully.

    Adaptive image transmission scheme based on human visual system in OFDM
    QI Zhong-rui,GAO Zhen-ming
    2005, 25(02):  335-337.  DOI: 10.3724/SP.J.1087.2005.0335
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    According to the conventional image transmission method, an adaptive image transmission scheme based on HVS in OFDM(Orthogonal Frequency Division Multiplexing) system over frequency selective slow fading channel was proposed in this paper. It combined adaptive sub-channel distribution technique with source partition and characteristics of fading channel to improve the quality of received image. In order to verify the good performance of the proposed method, three kinds of image were used in the simulations. Significant improvement in PSNR(Peak Signal Noise Ratio) of received image with adaptive image transmission relative to conventional one is demonstrated by the simulation results of three different image sources and theoretical analysis.

    Two approaches of color image retrieval based on run-length description
    HU En-liang,Feng Qiao-sheng,YANG Xiu-guo,LIN Yu-cai
    2005, 25(02):  338-340.  DOI: 10.3724/SP.J.1087.2005.0338
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    According to the conception of color run-length, a method of feature representation based on run-length matrix for color image was proposed,then two similarity criterions were given.In order to enhance the robusticity in feature representing,the cumulative transformation was defined for run-length matrix.After experimented for true images, the better achievement is obtained when retrieving texture images by our approaches.

    Curvature estimation on triangular meshes using NURBS fitting
    MAO Ying, TANG Jie, ZHANG Fu-yan
    2005, 25(02):  341-343.  DOI: 10.3724/SP.J.1087.2005.0341
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    This paper proposed a new algorithm to estimate Gauss and mean curvature on triangular meshes based on NURBS fitting. In this algorithm, double neighbors were selected for local fitting in the first place which involved border checking. For parameterization, directly projection method was used. Then by using least square NURBS fitting, surface function was acquired, which followed the traditional curvature estimation method. Through tests on meshes considering different resolution and noises, final conclusion can be drawn that our algorithm has good results and is more stable than other algorithms, thus is more applicable.

    Study on contour-based freehand sketch retrieval
    LI Man-wu, SUN Zheng-xing, GU Qing-dong
    2005, 25(02):  344-347.  DOI: 10.3724/SP.J.1087.2005.0344
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    This paper presented a contour-based freehand sketch retrieval method, which used Fourier Shape Descriptor to unify the shape representation of the sketchy graphics in the sketchy graphics database and user input and retrieved the images by calculating the similarity between them. This method improves the computation efficiency and avoids the order-sensitivity of the strokes. The result of experiments shows that the proposed method has good retrieval performance and efficient user adaptation.

    Software technology
    Research on the weighting exponent in fuzzy K-Prototypes algorithm
    WANG Jia-cai,ZHU Yi-hua
    2005, 25(02):  348-351.  DOI: 10.3724/SP.J.1087.2005.0348
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    Fuzzy K-Prototypes(FKP) algorithm integrating K-Means and K-Modes algorithm is suited for clustering mixed numeric and categorical valued data. The use of fuzzy techniques makes it robust against noise and missing values in the databases. But, it is an open problem how to select an appropriate weighting exponent α when run FCM(Fuzzy C-Means algorithm) or FKP. Some researchers have suggested that the best choice for α in FCM be probably in the interval \ based on their experimental results. In this paper, the algorithm for searching suitable α in FKP was presented. The experimental results on several real datasets show that the valid clustering can be achieved when α is under 1.5.
    Study and application of an open performance-test framework
    WU Heng-shan, YU Hua-bing
    2005, 25(02):  352-354.  DOI: 10.3724/SP.J.1087.2005.0352
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    This paper analyzed the principle of Grinder, an open performance test framework based on J2EE,and improved on this framework: adding a dynamic graph interface and sending scripts from console to clients. Finally we implement the TPC-W benchmark on the improved framework, and used it to test the national database management system-DM4.
    Web Service-based cross-organizational workflow model
    WANG Yong,CUI Hang
    2005, 25(02):  355-358.  DOI: 10.3724/SP.J.1087.2005.0355
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    Traditional workflow applications succeeded in a single organization domain, however it had only a few success in cross-organizational scenario. This paper analyzed the need of cross-organizational workflow, especially the heterogeneity and autonomy of cross-organizational workflow integration, established a cross-organizational workflow model which includes process model, interface model, and interaction model. It solves the problem of cross-organizational workflow integration.
    Research on structured operational semantics of UML sequence diagram推
    HUANG Long, YU Hong-min, CHEN Zhi-ming
    2005, 25(02):  359-361.  DOI: 10.3724/SP.J.1087.2005.0359
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    UML Sequence Diagram emphasizes particularly the process of message interaction of objects. But it lacks formal description of dynamic semantics, therefore goes against comprehension of the diagram and test case generation based on the diagram. Based on UML specification (version 1.5), this paper defined formal syntax of the diagram firstly and brought forward concept of Action-Point afterwards; thus discuss and put forward the structured operational semantics of message action of single object and the whole sequence diagram, provided the precondition of model checking and the test cases generation which based on sequence diagram.
    Real-time extension of Z and the application mode based on multi-viewpoint
    HEN Guang-ming,CHEN Sheng-qing, ZHANG Li-cheng
    2005, 25(02):  362-364.  DOI: 10.3724/SP.J.1087.2005.0362
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    RT-Z is the specification language integrating Z language with timed CSP, which is the extension of sequential communication processes in real-time aspect. RT-Z combines the advantages of the state expression in Z with the advantages of the temporal relation and concurrent expression in timed CSP. Thus, RT-Z has powerful expressive abilities suitable for states specification. The classified principles for the extension to Z in real-time aspect and its applied features were discussed. Based on the analysis of semantic integration of RT-Z, a multi-viewpoint applied pattern with the extension of Z in real-time aspect was put forward.
    Arithmetic for matching multiple patterns based on improved doubly-chained tree
    TANG Hao, LU Xian-liang
    2005, 25(02):  365-366.  DOI: 10.3724/SP.J.1087.2005.0365
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    In the arithmetic for matching multiple patterns based on digital search tree,the physical storage mode of digital search tree is doubly-chained tree. Using the idea of KMP arithmetic, digital search tree has been turned into improved doubly-chained tree through added assistant jump-node. The improved storage mode and arithmetic have quickened the speed of matching, and have implemented non-backtracking in process of matching.
    Study on ADL-Based automatic generation of compiler in embedded system
    REN Xiao-xi, LI Ren-fa, ZHANG Ke-huan
    2005, 25(02):  367-369.  DOI: 10.3724/SP.J.1087.2005.0367
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    Compiler is an important part of embedded system software, it has great impact on software development of embedded system. This paper analyzed the structure of an compiler automatic generation tool genmd, based on the idea of combining ADL with retargetable compilers, and put emphasis on abstracting and modeling of instruction recognition and machine description generation. Meanwhile, a method was provided and implemented to solve the limitation of genmd that was unable to support instructions of branch and jump.
    Research on distributed computing based on JavaSpaces
    ZHU Wen-hua, WANG Qian
    2005, 25(02):  370-373.  DOI: 10.3724/SP.J.1087.2005.0370
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     JavaSpaces is a Java-based implementation of tuplespace and it provides a conceptually simple but powerful solution to design and build distributed systems that are reliable, flexible and extendable. This paper detailed the program model and application patterns of JavaSpaces. And a distributed parallel computing framework based on JavaSpaces was also introduced and tested.
    Parallel genetic algorithm based on learning mechanism
    ZHANG Gui-juan, WU Zhao-hui,LIU Xi-yu
    2005, 25(02):  374-376.  DOI: 10.3724/SP.J.1087.2005.0374
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    Based on the concept of biotic community in Biology, a 3-layer model named community-population-individual was proposed. Meanwhile, a parallel genetic algorithm based on learning mechanism (PGABL) was developed on this model. As the data structure for collaborations between subpopulations, the Blackboard model was introduced. And three learning operators are designed, through which PGABL combines the advantages of genetic evolution and genetic learning that improves the performance of traditional genetic algorithm effectively. Experimental results show that PGABL is of good adaptability and stability.
    Information security
    Survey on key management for secure multicast communications in mobile Internet
    WANG Guo-jun,LIAO Lin,MA Hao
    2005, 25(02):  377-380.  DOI: 10.3724/SP.J.1087.2005.0377
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    A survey of many kinds of schemes was present about secure multicast key management. In the meanwhile, in view of mobile environment, frequent handoff and poor reliability are the key properties and differences. Thus the secure multicast key management strategy in mobile Internet was discussed deeply in the survey.

    New scheme for digital time-stamping based on signature
    ZHANG Ya-ling, YU Yong,WANG Xiao-feng, WANG Tie-ying
    2005, 25(02):  381-382.  DOI: 10.3724/SP.J.1087.2005.0381
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    Billing service question is not solved in the existing time-stamp schemes. In other words, how the time-stamping Service will bill the service to its customers when they ask it for a Digital time-stamping. This article described the existing time-stamping schemes, based on blind signature,a new scheme solving the problem was presented. In the new scheme an issuing entity of tickets is introduced to solve billing service question. Based on RSA signature, an integrated time-stamping system was constructed in this article.

    Anomaly detection based on improved negative selection matching algorithm
    XIAO Xiao-li,TIAN Yue-hong,CHEN Chuan
    2005, 25(02):  383-385.  DOI: 10.3724/SP.J.1087.2005.0383
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     A matching algorithm based on the negative selection for anomaly detection was presented in this paper. In the algorithm the effects of position between two temporal sequence to matching degree were considered. So it could distinguish accurately self and non-self, and reduced the size of detective set effectively. Using normal sequence calls, the initial detective set was created, and the detective set was extended by learning, according to the proportion of anomaly temporal sequence to judge whether this sequence was anomaly. Finally, the results of experiment was given.

    Image watermark robustness evaluative method based on synergetic order parameter
    CHEN Yong-qiang, HU Han-ping, LI Xing-tian
    2005, 25(02):  386-389.  DOI: 10.3724/SP.J.1087.2005.0386
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     Aimed at image watermark robustness, an evaluative method based on synergetic order parameter and its usage was first advanced. Many kinds of robust experiment of Image carrier were done. After procession, the synergetic original order parameter of patterns in the set were calculated and compared. Through validation by the order parameter evolvement curves, their robust conclusions were gotten. This method is more convenient and applied than the correlative coefficient method, although the two methods have same conclusion.

    New multilayer chaotic algorithm for video encryption with changeable key
    MA Da-wei, ZHENG Ying-ping, WANG Ling-qun
    2005, 25(02):  394-395.  DOI: 10.3724/SP.J.1087.2005.0394
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    Auther proposed a brand new encryption method for video sequence, based on Chaos theory. This method adopted multilayer chaotic transformation,therefore,the key can be changed during theencryption process, and the security performance is greatly improved.Besides, this algorithm inherited the selective encrytion idea, it only processed the key messages in the video sequence, so encryption efficiency is enhanced remarkably to satisfy the requirements of realtime communication. Furthermore, through computer simulations, the security performance and encryption efficiency of this method was demonstrated.

    Design of spam E-mail filter system which independent of E-mail server
    DING Peng, YANG Yong-tian, LUO Zhi-yun, ZHENG Ke-xin
    2005, 25(02):  396-398.  DOI: 10.3724/SP.J.1087.2005.0396
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    This paper introduced a scheme of spam E-mail filtering system which works before mail server independently. This spam filtering system includes E-mail capturing module, E-mail filtering module, database and administrant module. This paper recommended the E-mail filtering module which adopts the heuristic filtering technique based on the Bayesian Statistic method detailedly. Finally,a testing result of the system was given in this paper.

    Research and implementation of software registration system based on asymmetric cryptography
    ZHANG Yi-ting,YANG Ming
    2005, 25(02):  399-402.  DOI: 10.3724/SP.J.1087.2005.0399
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    Compelling registration/validation and the ability of anti-cracking are core problems in software copyright protection area. Traditional registration methods mainly depended on the strength and secrecy of validation algorithm, and thus had a low reliability. This paper proposed a new software registration and validation method adopting asymmetric cryptography technique and license file, and also gave the detailed design and implementation of PubCMCenter (Software Publish Control and Manage Center) system based on this method. In the system, the publisher preserves private key, while software users only have the public key that is needed to validate the license file and have no ability to generate the license. Furthermore, this system can also make modular authorization according to the user’s level. Compared with traditional techniques, this system is easier and safer to use.

    E-cheque payment system based on digital watermarking and digital signature
    DAI Hua,ZHANG Lin-cong,LI Bing-fa
    2005, 25(02):  403-406.  DOI: 10.3724/SP.J.1087.2005.0403
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     The secure problems of E-cheque used in electronic commerce payment were studied. Based on the analysis of the developing circumstance and the security gap of it, a security guarantee system combining watermarking and digital signature were proposed. The double entity authentication and watermarking content authentication made it impossible to gain illegal access to E-cheque, to edit or to forge it. According to the analysis, the security, creditability and authenticity of the E-cheque can be achieved by the system.

    Research on self-similarity of DDoS traffic based on the UDP
    REN Dong-dong, YANG Dong-yong
    2005, 25(02):  409-411.  DOI: 10.3724/SP.J.1087.2005.0409
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    In this work, DDoS based on UDP was simulated in NS-2, Results show that traffic of network still has self-similarity when DDoS based on UDP is happening in the network regardless of different kind of attack model and different network load. This is significant to research of characteristic of DDoS traffic and defense against DDoS.

    Robust watermark technology based on scrambling and multi-embedding
    CHEN He-feng, ZENG Wen-qu, NIE Du-xian
    2005, 25(02):  412-413.  DOI: 10.3724/SP.J.1087.2005.0412
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    A watermark algorithm was improved in embedding and extracting. One watermark pixel was embedded many times into DC, mid-frequency and low-frequency coefficients of the same DCT block. What it dose was not averaging watermark values extracted from one block, but applied a self-studying method to get the last watermark. The watermark system is more preferable.

    Typical applications
    Real-time vehicle game engine base-on multi-body dynamic
    HUAI Yong-jian,WANG Mei-feng, ZUO Zheng-xing, HUANG Xin-yuan
    2005, 25(02):  414-416.  DOI: 10.3724/SP.J.1087.2005.0414
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    Real-time moving vehicle modeling and dynamic behavior simulation is an important research in virtual reality game engine. In this paper, a real-time vehicle game engine was designed and presented. Auther provided a method of real-time vehicle rendering based-on multi-body dynamics in engine, and could simulate different of dynamic behaviors as real as in real world. The other techniques such as collision detection, 3D music rendering, real-time virtual environment rendering were also realized. Thus,it can enhance the immersion when user walk-through virtual environment.
    Ground-based LIDAR data simplification based on quad-tree partition
    LUO De-an, LIAO Li-qiong
    2005, 25(02):  420-421.  DOI: 10.3724/SP.J.1087.2005.0420
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    On the basis of analyzing the data of ground-based LIDAR and existing point cloud data simplification algorithms, a new ground-based LIDAR data simplification algorithm based on quad-tree partition was presented, the basic theory and the methods to make it reality were discussed in details. Some conclusions come from tests: the algorithm presented in this paper can get a high data compression ratio to point cloud data distributing on a plane approximately, and can keep edges perfectly.
    Research and design of the city public transportation query system
    ZHANG Yong-mei, HAN Yan, CHEN Li-chao
    2005, 25(02):  422-425.  DOI: 10.3724/SP.J.1087.2005.0422
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    Spatial data structure of the implementation for the city public transportation query system was proposed. Based on Dijkstra's shortest path algorithm, an intelligent algorithm for state space searching for K shortest path was presented with the aid of the thoughts of state space searching and dynamic cut branch in artificial intelligence. The algorithm could show inquiry traffic route, riding scheme and so on through electronic map, and change maps of different cities. The practical tests of the system show that the query system designed in the method presented by this paper has the characteristics of high speed, multimedia display, convenient maintenance, and powerful commonality.
    Specification and verification environment for embedded system over CDM
    LU Zhao, ZHAO Min-yuan, GU Jun-zhong
    2005, 25(02):  426-429.  DOI: 10.3724/SP.J.1087.2005.0426
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    This paper illustrated a new approach and environment to describe and simulate the embedded system. Firstly, auther constructed the CDM models to describe the design requirements of the specified system. Secondly, in order to get the aim of verification of a specified system, according to the converting rules, the approach automatic converted the requirements documents to the CDM models and SystemC codes to simulate a specified system. Finally, an application example using the above approach was illustrated.
    Distributed control scheme for power transformation system based on network agent of VxWorks
    LIU Qing-shan, JIANG Xiao-hua(
    2005, 25(02):  433-436.  DOI: 10.3724/SP.J.1087.2005.0433
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    An automatically-controlled power transformation system was studied and a distributed control scheme for the system was proposed and implemented in order to improve the safety and efficiency of power systems. Advanced software and hardware techniques, system architectures and safety requirements of power transformation systems were all taken into account. Real-time event and disturbance logs and control commands were communicated over a local power transformation system based on the embedded operating system of VxWorks and the hardware platform of PowerPC860 CPU. The distributed control scheme for power transformation systems realized supervisory control, data acquisition and logic functions, and has been validated by industrial experiments.
    Research of chip simulation based on COM
    TANG Ming-dong,LEI Dian
    2005, 25(02):  437-439.  DOI: 10.3724/SP.J.1087.2005.0437
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    Using COM as an object to simulate the structure, function, character and signal transfer of chips was introduced. According to chip simulation, the concept of software chip was presented, which can be used to make simulation model component-based and improve its reusability, thus it has some value in application for system simulation and component-based software design.
    Design and realization of the Ethernet phone based on SDA80D51
    JIA De-sheng, HUANG Yong-feng
    2005, 25(02):  440-442.  DOI: 10.3724/SP.J.1087.2005.0440
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    An Ethernet IP phone design was introduced in this paper. The design used SDA80D51 as the MCU and DSP unit to realize an efficient Ethernet phone. Some advice on the program of the MCU system was also given.
    Design and implementation of general real-time data sampling in Windows 2000/XP
    WU Li-na, GAO Jing-yang
    2005, 25(02):  443-445.  DOI: 10.3724/SP.J.1087.2005.0443
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    The paper analyzed some methods of real-time data sampling in Windows 2000/XP platform and proposed an optimal solution using the mechanisms for real-time application in Windows 2000/XP. For disserting the design idea, A vibration signal sampling system was proposed as an example application and experimental data was given which indicates that this solution can fulfill the requirements of real-time application. The practical result has proved to be successful.
    Optimizing AMI model of CORBA based on the proxy pattern
    HE Zhi-hua, ZOU Bei-ji
    2005, 25(02):  446-448.  DOI: 10.3724/SP.J.1087.2005.0446
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    The message communication is the key of EAI. In order to improve the facility, reuse and expansibility of message, this paper put forward a communication model based on proxy pattern, which reserved the core arithmetic of callback and polling, decomposed the coupling of the original AMI model and optimized the technology of callback, which made more satisfy the need of expansibility and reuse in EAI. Here, the ways to design and implementation, the simulative testing datum in project were introduced. The result shows that the model can be preferably satisfy the need of business in EAI.
    Research on question similarity algorithm for intelligent question answering system and its implementation
    GUO Xiao-yan, ZHANG Bo-feng, FANG Ai-guo, ZHOU Chuan-fei
    2005, 25(02):  449-452.  DOI: 10.3724/SP.J.1087.2005.0449
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    The intelligence and human-computer interaction of existing answering system are not good enough. To overcome the shortages, this paper presented a complete intelligent question answering System (IQAS) implementation. To enhance the veracity of matching between question from student and questions in database, the algorithm of question similarity was researched. By using auto segmenting algorithm, question similarity transformed the relativity of collections. A good study model was found to optimize segmenting weights from BP model, a supervised-machine learning task. Test results show that the algorithm can help IQAS improve veracity and intelligence and has practical value.
    Design and implementation of the Web camera based on MPEG4
    FANG Jing-shuai, DOU Wen-hua
    2005, 25(02):  453-455.  DOI: 10.3724/SP.J.1087.2005.0453
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    Network bandwidth is one of the bottlenecks of the Web cameras performance. So we proposed an approach of Web camera based on MPEG4. This paper introduces the design of Web cameras hardware and software. With PNX1301 chip, an applicable Web camera was implemented. Then the design and implementation of the PCI arbiter was given in detail.
    Research on technology of information integration based on ontology
    WU Hao,XING Gui-fen
    2005, 25(02):  456-458.  DOI: 10.3724/SP.J.1087.2005.0456
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    With the rapid development of semantic Web,ontology played a prominent role on it.In the process of information integration,ontology solved the semantic heterogeneity problem of distributed, heterogeneous and autonomous data source.This paper introduces a ontology-based hybrid approach of inforamtion integration , which provides users the same interface for accessing to data corresponding to the semantic.
    Special encryption and sign techniques in mobile auction system
    QIAO Shao-jie, PENG Jian, ZHENG Xue-qiang, LIN Hong-jun
    2005, 25(02):  459-462.  DOI: 10.3724/SP.J.1087.2005.0459
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    Based on the implements of the secure mobile auction system, the paper analysed the security requirements of this system, introduced the special encryption and sign techniques in mobile auction system, these techniques contained the making, storing and updating of the secret key, the encryption, decryption and the self-sign certificate model of SOAP message in server, the implement of the encryption engine and the sign engine in client. This system can be successfully transplanted to mobile devices in order to improve the security of the wireless Web Services.
    Design and implementation of CNC kernel in CNC lathe emulation system
    ZHOU Chong , QIAN Kun-ming , QI Xin
    2005, 25(02):  463-465.  DOI: 10.3724/SP.J.1087.2005.0463
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    This paper gave an example of emulational system of the numerical control lathe. It introduced the design and implement of an important module-numerical control kernel. It expatiated the implement of three aspects which included input and display, code translation, intelligent checking error, and it also provided constructing bintree algorithm about language G’s syntax analysis. It realized the numerical control kernel emulation thoroughly using Lingo.
    Realization and research on ship remote sensing monitorand communication system based on Inmarsat D+
    WU Dong-qing,LIU Jiu-nu,LI Zhe-lin
    2005, 25(02):  466-468.  DOI: 10.3724/SP.J.1087.2005.0466
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    Inmarsat D+ is a new service provided by Inmarsat in recent years. Its application in remote sensing, monitor and communication system is still being explored both in China and abroad. The paper introduced the compositions of the remote sensing, monitor and communication system based on Inmarsat D+, and presented its advantages comparing with its rivals. It explained the architecture of the novelty system through the illustration of a ship manage system based on Inmarsat D+. The system works smoothly for a ship supervision organization in China.
    Architecture of J2EE-based workflow engine
    XU Jian-jun, TAN Qing-ping, YANG Yan-ping
    2005, 25(02):  469-471.  DOI: 10.3724/SP.J.1087.2005.0469
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    Workflow engine is the core component of workflow system, architecture of which is vital to the whole system. This paper addressed the architecture of J2EE-based workflow engine, which was consisted of six components: parser, process manager, executor, task assigner, event server, time server and client interface. By the comparisons with other similar research works, the advantages of this approach in terms of applicability, expansibility, interview mode and transaction management were illustrated.
    Effective descriptive model of E-commerce merchandise and the multi-website searching mechanism
    PENG Dai-yi ,YIN De-hui, LI Bing-fa
    2005, 25(02):  472-474.  DOI: 10.3724/SP.J.1087.2005.0472
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    Although E-commerce was being popularized and applied all over the world, there were still unsolved problems in current E-commerce modes. Among them, the fact that there was no uniform description for E-merchandise is a critical limit for the development of E-commerce. Besides, there was not an effective mechanism for describing website relationship, enabling effective multi-website search. Aimed to solve above problems, this paper proposed an uniform description and a relationship model for E-merchandise, which were based on XML. Afterwards, a distributed intelligent agent framework was introduced to realize a multi-website searching mechanism for E-commerce based on prior relationship model.
    Design of Cache module for distributed RAID
    2005, 25(02):  475-477.  DOI: 10.3724/SP.J.1087.2005.0475
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    Architecture of Distributed Redundant Arrays of Inexpensive Disks (DRD) is different from centralized RAID systems. Auther designed a Cache module based on snooping protocols in distributed RAID systems. Snooping protocols rely on a shared bus between processors for coherence, so snooping protocols require high bandwidth of the shared bus in multiprocessor systems. The main memory to several data blocks were divided and mirrored these data blocks in Cache.The designed Cache module requires less bandwidth of the network. Because it requires less data operation, the performance of the DRD system improves. This paper analyzed benchmark performance of the designed Cache module, and also compared the method to achieve coherence in designed Cache module with the methods to achieve coherence in multiprocessor system.
    EAI-oriented and high-availability and loose-coupling XJCA
    LEI Ai-ping, YIN Jian-wei,CHEN Gang, DONG Jin-xiang
    2005, 25(02):  478-480.  DOI: 10.3724/SP.J.1087.2005.0478
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    EAI (Enterprise Application Integration) must integrate all kinds of heterogeneous data resources and different business process. JCA is one J2EE-based solution which can solve these problems quite well. To avoid the limitation of immature specifications and solve different applying problems in current JCA, this paper expanded JCA mainly from the point of view of EAI, so that it could meet high-availability and loose-coupling in EAI.
    Study and exploitation for center-controller of electromotion automobile based on CAN Bus
    JIAN Quan-bin, SHEN Bao-suo, CHEN Hong
    2005, 25(02):  481-484.  DOI: 10.3724/SP.J.1087.2005.0481
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     In order to control and manage the dynamic system and other vehicle subsystems of an electromotion automobile effectively , this article introduced the exploitation process of a center-controller which was based on CAN-Bus, and discussed its structure and the design and realization of its hardware and software as well as the establishment of CAN Bus communication protocols. It is proved in the condition of real car-environment that the center-controller can be seasoned with the electromotion automobile and work well, and achieve the purpose of controlling and managing the whole cars dynamic systems.
    Partner selection in agile virtual enterprise based on grey relation analysis
    DU Lai-hong, CHEN Hua, FANG Ya-dong
    2005, 25(02):  485-489.  DOI: 10.3724/SP.J.1087.2005.0485
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    The character and meaning of agile virtual enterprise was analyzed, and gray relational theory is applied in the partner selection. The paper firstly brought forward gray relational mathematic model, and then lays emphasis on the illustration of agile virtual enterprise evaluation infrastructure, and on the basis of constructing of system digitized model, presented principle, method and approach of muti-levels gray relational selection by means of instance analysis.
    Realization on online-test with winsock
    CHEN Ai-ming,DONG Zhao-xia
    2005, 25(02):  490-492.  DOI: 10.3724/SP.J.1087.2005.0490
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    In this paper,auther discussed the realization on online-test with the communication function of Winsock in VB combining database and other technologies. The online-test system functions and realization ways were introduced. The transmission of text with graph,the strategy of selecting test questions,and the scoring results are chiefly discussed. Some examples and key codes are also provided. It is simple to realize this system,and it is easy to operate and expand the functions. The system can be a tool for online-test in LAN.
2024 Vol.44 No.9

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