Author Login Editor-in-Chief Peer Review Editor Work Office Work

20 May 2009, Volume 35 Issue 10
    

  • Select all
    |
    Degree Paper
  • LING Yun-xiang; LI Rui; LAO Song-yang
    Computer Engineering. 2009, 35(10): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2009.10.001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on nature touch gesture interaction of future command post, this paper researches the conception representation of user operation, introduces an interaction mapping method of syntax/semantic conformity from user operation to multi-fingers touch. The user operation mapping method may support development of multi-mode/multi-modal human-machine dialogue system.

  • YUE Pei-pei; CHEN Jie; LIU Jian; Sheraz Anjum;
    Computer Engineering. 2009, 35(10): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2009.10.002
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An efficient design of Network Interface(NI) is proposed for the Networks-on-Chip(NoC) with two-channel routers. It is compatible of the AMBA protocol, and can choose the communication type according to the request of IP cores. It hides the communication detail to the IP core, for the sake of simplification of the software, and it can take full advantage of the two-channel router which has separate data packet channel and control packet channel. The area of the NI after synthesis is only 0.3 mm2 in SMIC 0.13 μm technology.

  • XIAO Jiang; HU Ke-liang; DENG Yuan-yong
    Computer Engineering. 2009, 35(10): 7-10. https://doi.org/10.3969/j.issn.1000-3428.2009.10.003
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper introduces the result of a test that evaluates the effectiveness of Compute Unified Device Architecture(CUDA) using NVDIA GeForce8800GT and the compiler Visual Studio 2008. It tests the speed of NVIDIA CUBLAS, CUDA kernel, common C program, Intel MKL BLAS, CUDA driver API program, FFTW and CUFFT Library in matrix-multiplication and Fast Fourier Transform(FFT). Test result of the large scale data shows that the computing ability of GPU is 25 times better than that of CPU.

  • BAI Xing-zhen; LI Xiao-mei; WU Na
    Computer Engineering. 2009, 35(10): 11-13. https://doi.org/10.3969/j.issn.1000-3428.2009.10.004
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The mobile Agent routes algorithm based on object-sensing, named OSER, in Wireless Sensor Networks(WSN) is designed in this paper, which is based on the sensing degree of the objective information and remaining energy of the sensor nodes. In the design of the best static route nodes list, the nodes sense their energy degree information and the local network topology are founded among effective neighbour nodes. The neighbour node, which energy degree is best among other neighbour nodes, is selected as the next node for Agent to move. Mobile Agent moves along the nodes list, proceeding information fusion. The analysis of the algorithm indicates that the energy consumption of OSER is less, and its energy consumption equilibrium is well, which is good for keeping stability and prolonging the life of the WSN.

  • SUN Yue-heng; CAO Gui-hong; HOU Yue-xian
    Computer Engineering. 2009, 35(10): 14-17. https://doi.org/10.3969/j.issn.1000-3428.2009.10.005
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Word clustering is one of important natural language processing issues in speech recognition and intelligent information retrieval, etc. This paper presents a symmetric clustering model based on mutual information. For the model not taking the order of words into account, it proposes a new asymmetric clustering model including two sub models, conditional clustering model and predictive clustering model. Experimental results on large scale data set show that compared with the symmetric clustering model, the asymmetric clustering model is a more effective one for clustering words.
  • WU Gui-fang; JANG Se-young; KWAK Hoon-sung; DAI Gao-le
    Computer Engineering. 2009, 35(10): 18-20. https://doi.org/10.3969/j.issn.1000-3428.2009.10.006
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A VoIP device is intended to be developed, which can receive and save multimedia advertisement information, and its advertisement service model is presented. The VoIP device can save the advertisement information received from a push server of common carriers in its internal storage, and only the information which is necessary for a user is delivered promptly at any time. The experiment shows that its processing time per kernel instruction is only 18 ms, and it can process 10 ~ 12 calls per second. The time for software processing is only 4 ms and the average time for finishing once connecting and disconnecting an outbound call takes only 93 ms. It is more advantageous in call completion rate than current VoIP communication devices.

  • YANG Ji-jun; XU Wei-sheng; FENG Yun-sheng; WU Qi-di; MIAO Cheng
    Computer Engineering. 2009, 35(10): 21-24. https://doi.org/10.3969/j.issn.1000-3428.2009.10.007
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    After analyzing the process of relief resources scheduling in emergency logistics, a multi-mode layer network for relief resources scheduling is created. Based on above network, this paper brings forward the concept of a congregation of scenes in order to describe the uncertainty of traveling time in the transporting Web owing to emergency event. By employing the Minimax theory, the model of absolute and relative reliable routing are given in order to find reliable path. A numerical example is presented to demonstrate the usefulness and feasibility of this model.

  • LI Huan; ZHOU Shuai-feng; QIN Zheng
    Computer Engineering. 2009, 35(10): 25-26. https://doi.org/10.3969/j.issn.1000-3428.2009.10.008
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A new mesh deformation algorithm with restriction of multiple fixed points is proposed, which controls the shape of model exactly without using lattice during its implementation process. It needs less calculations. Experimental result shows this algorithm improves the limitation and complexity of the traditional free deformation methods effectively.

  • ZHAO Hai-long; MU Zhi-chun; ZHANG Xia; DUN Wen-jie
    Computer Engineering. 2009, 35(10): 27-29. https://doi.org/10.3969/j.issn.1000-3428.2009.10.009
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    LDA is widely used for linear dimension reduction. However, LDA has some limitations that one of the scatter matrices is required to be nonsingular. Discriminative Common Vector(DCV) is one of the most successful methods which overcomes the problem caused by the singularity of the scatter matrices. But when DCV is directly used to reduce the dimension of the ear images, the computational expense of training is still relatively large. A new method is proposed in this paper that the low frequency subimages are obtained by utilizing two-dimensional wavelet transform and the features are extracted by applying DCV to the subimages. The experimental results show that the proposed method achieves better performance than Fisher face method and the computation burden is also reduced greatly.

  • Software Technology and Database
  • WANG Xiang-qian; ZHANG Yun-quan; HOU Xiao-wen
    Computer Engineering. 2009, 35(10): 30-32. https://doi.org/10.3969/j.issn.1000-3428.2009.10.010
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    More and more parameters are introduced with the development of parallel computational model. This paper carries out researches on the framework of a Dynamic Execution and Machine Parameter Analysis Toolkit(DEMPAT) for parallel computational model parameters. A portable memory hierarchy parameter acquisition module is implemented, which shows high speed and accuracy in the experiments.

  • CHEN Jun-pu
    Computer Engineering. 2009, 35(10): 33-36. https://doi.org/10.3969/j.issn.1000-3428.2009.10.011
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Network processors have a parallel architecture while high level languages designed for them usually have sequential semantics. When compiling sequential programs with parallelization transformation, synchronization is required which is critical to the performance of the application. This paper proposes a partition transformation to optimize synchronization for programs on network processors, and more parallelism is exposed, which is otherwise hidden. Experiments data shows that the proposed optimization method significantly improves program parallelism and achieves speedup for some typical network applications.
  • NIU Xiao-na; GUO Yun-fei; LUO Min-xuan; WANG Chao;
    Computer Engineering. 2009, 35(10): 37-39. https://doi.org/10.3969/j.issn.1000-3428.2009.10.012
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    On basis of analyzing QoS function module and the structure of AMCC network processor, the network data plane software based on NP3450 is designed and implemented by using microcode and high-level programming language. Such mechanism as deep packet classification, the second look-up table, three scheduling and four groups of prospective entry-limit are introduced. The fine-grained QoS control based on stream is implemented. Experimental results show this design scheme is feasible.
  • HUANG Hui-ping; LUK Wai-shing; XIAO Lin-fu; ZHAO Wen-qing
    Computer Engineering. 2009, 35(10): 40-43. https://doi.org/10.3969/j.issn.1000-3428.2009.10.013
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A fast Dynamic Priority Search Tree(DPST) is proposed for 2-D range query in form of ([x1: x2], [-∞: y]). The proposed DPST stores input data only in its leaf nodes and performs tree rotation in constant time. Let n be the total number of leaf nodes in the tree, and k be the number of solutions in query. The tree requires takes O(n) storage space and takes O(logn) for insertion and deletion, and O(logn+k) time for query.
  • TAO Jie; YANG Min
    Computer Engineering. 2009, 35(10): 44-48. https://doi.org/10.3969/j.issn.1000-3428.2009.10.014
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Dynamic Tracing(DTrace) can be used on live production systems to tune and monitor both user programs and operating system itself. When DTrace is enabled on live systems, it introduces some performance penalty. This paper presents the performance model of DTrace by analyzing its software architecture and its internal work flow, and obtains this model’s parameters in real world. Experiments show this performance model can predicate the performance penalty correctly.
  • BI Jian-ting; SU Yi-dan
    Computer Engineering. 2009, 35(10): 49-50. https://doi.org/10.3969/j.issn.1000-3428.2009.10.015
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the problems existed in traditional method of query expansion, an expansion method for language-crossed query based on Latent Semantic Analysis(LSA) is proposed, which uses clustering to improve accuracy of expansion word sets, and uses LSA to implement query expansion without translation. The impact of error in translation is eliminated. Experimental results show this method achieves better performance.
  • JIAN Ling
    Computer Engineering. 2009, 35(10): 51-53. https://doi.org/10.3969/j.issn.1000-3428.2009.10.016
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Performance test is an important part in the test tuning. In order to accurately access the system performance, this paper uses "simulating the real user experience" principle, realizes a serial of performance test on a typical B/S system, including the preparation, design, development and implementation. Through the performance test, the existing problems of the system are found. Tuning results confirm that the accuracy of the test methods.

  • LIU Feng-long
    Computer Engineering. 2009, 35(10): 54-56. https://doi.org/10.3969/j.issn.1000-3428.2009.10.017
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to guarantee the continuous and efficient performance of Oracle databases, a CORBA-based Distributed Oracle Monitoring System(CDOMS) is designed and implemented. “Agent plus oracle view surface” is used in CDOMS, and flexible configuration, two-level based content presentation and prediction techniques are adopted in CDOMS adopts to achieve cost-efficient monitoring. It is proved experimentally and practically that CDOMS can continuously monitor distributed Oracle database system and server’s resource with different granularities in real-time, alarm for potential faults in advance, analyze the database system comprehensively and manage the remote nodes effectively. Experimental result and the actual application of nomenclature project prove effectivity of the system.
  • PAN Xian-zhang; MI Gen-suo
    Computer Engineering. 2009, 35(10): 57-59. https://doi.org/10.3969/j.issn.1000-3428.2009.10.018
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Existing Web framework does not take fully consideration of pojo object-oriented programming and the mapping of XML to relational databases, that resulting in tight coupling between the database table and other object with pojo. Aiming at this problem, this paper presents a development framework based on Schema, which considers to the database table reliance on DTD, layouts of the system code pojo intensively and rational, and convenient for service object to call DAO object. This framework is easy to expand and maintain.
  • ZHONG Dong; ZHU Yi-an; WANG Yun-lan
    Computer Engineering. 2009, 35(10): 60-61. https://doi.org/10.3969/j.issn.1000-3428.2009.10.019
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the problem that traditional service discovery technique can not use past action experience, a novel service discovery technique based on past is proposed, and a new service discovery model called Past Action Service Discovery(PASD) is introduced. The validity of this model is proved by encapsuling it into recommendation service. Simulation experimental results show the system based on PASD model can promote efficiency of service discovery, and the accuracy is about 80%.

  • NA Li-chun; CHEN Qing-kui
    Computer Engineering. 2009, 35(10): 62-65. https://doi.org/10.3969/j.issn.1000-3428.2009.10.020
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The financial data of enterprise group covers many big districts through Internet, and the financial software and dada system in the group present the heterogeneous characteristic. In order to effectively gathering the financial monitoring data of enterprise group, the concurrent workflow is adopted to construct the gather model for financial monitoring data in this paper. By using of the basic Financial Data(FD), the tree-shape workflow is constructed. By making use of the gather server for FD, the multi-level gather mechanism is proposed. This model is implemented through the tree-shape workflow and the multi-level gather mechanism. Analysis and experimental results show that this model has good gather efficiency and linear extendibility. It can be fit for the need of information building for enterprise group.

  • WANG Chuang-wei
    Computer Engineering. 2009, 35(10): 66-67. https://doi.org/10.3969/j.issn.1000-3428.2009.10.021
    Abstract ( )   Knowledge map   Save
    This paper presents an IOQ model and the algorithm for a complex services from the various element services. The composition of such services is transformed into more simple question, which is reverse inquiry of element service and services discovery of input set from the input set and output set of known services, in the services set of meeting the quality of service constraints. Algorithm model and pseudo-code of the services composition are proposed which aims at the services composition.
  • GUO You-xian; ZHANG Dong-zhan
    Computer Engineering. 2009, 35(10): 68-72. https://doi.org/10.3969/j.issn.1000-3428.2009.10.022
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Because of the existing differences between XML data and the traditional relational data, the traditional method of data warehouse ETL is no longer suitable for dealing with XML data. This paper proposes the XETL method which is based on pattern tree and can be applied to transfer and deal with XML data. This paper starts with the research on XETL pattern based on data model and predicate model, and defines the four main transference operations in the XETL process based on the XETL model, , which are attribute selection, null attribute operation, aggregation and attribute renamed.
  • FAN Yuan-kang; HU Xue-gang; XIA Qi-shou; ZHU Yong
    Computer Engineering. 2009, 35(10): 73-74. https://doi.org/10.3969/j.issn.1000-3428.2009.10.023
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper introduces some special processing methods of preprocessing in the field of Web log mining. The algorithm based on frame page filtering and session identification is proposed at the stage of transaction recognition. Before identification, frame pages are filtered, and initial session sets are constructed by traditional method of session identification. The quality of session set is improved using a method of union and rupture. Experimental results show the algorithm enhances the quality of session identification.

  • YE Xiao-tong; DENG Yun; JIAN Qing-ming
    Computer Engineering. 2009, 35(10): 75-77. https://doi.org/10.3969/j.issn.1000-3428.2009.10.024
    Abstract ( )   Knowledge map   Save
    This paper proposes a resolution to resolve the complex problem of transforming function expression between different XML language products. Based on the corresponding relationship between function expression and binary tree, the resolution adopts array of pre-order traversal and in-order traversal to identify the unique binary tree in XML document properties, so that the function expression can be generally resolved by other XML language products. The relative key technologies of parsing and transforming XML function expressions are researched and described in detail. The proposed resolution can improve the universality and efficiency of transforming function expression.

  • HUANG Ming-xuan; ZHANG Shi-chao; YAN Xiao-wei
    Computer Engineering. 2009, 35(10): 78-79. https://doi.org/10.3969/j.issn.1000-3428.2009.10.025
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the limitations of existing query expansion, this paper proposes a novel query expansion algorithm of relevance feedback based on users’ query behaviors, as well as the technique of item-all-weighted association rule mining in retrieved relevance documents. According to the duration of user’s clicking and browsing, or the existence of some querying behaviors such as downloading, this algorithm is able to determine whether a document is related to users’ query intentions and interests, automatically extract those item-all-weighted association rules related to original query from retrieved relevance documents to construct an association rules-based database, and collect terms related original query as expansion terms from the database. Experimental results show the retrieval performance of the algorithm is improved remarkably.
  • CHEN Shu-sheng; LIU Wei-dong
    Computer Engineering. 2009, 35(10): 80-82. https://doi.org/10.3969/j.issn.1000-3428.2009.10.026
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A novel graph-based adaptive multi-join query optimization algorithm is proposed. The relationship between the arrival time of relation result set and its size is analyzed. The graph-based multi-join query is improved with the idea of adaptive query optimization and dynamic adjustment. Simulation experimental results show the time complexity of this algorithm is O(n) in case of best situation, and improves the efficiency of query.
  • LI Jing
    Computer Engineering. 2009, 35(10): 83-85. https://doi.org/10.3969/j.issn.1000-3428.2009.10.027
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    XML security view and query rewriting are the key techniques for access control. This paper researches the query rewriting problem for XML recursive security view, and presents a query rewriting algorithm which based on XPath query and can handle recursive view. This algorithm avoids the view materialization and maintaining, and has high currency. Experimental results show that this algorithm is effective.

  • WU Ting-peng; ZHANG Yu; LIU Yu-yu
    Computer Engineering. 2009, 35(10): 86-88. https://doi.org/10.3969/j.issn.1000-3428.2009.10.028
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A parallel Garbage Collector(GC) based on Just-In-Time(JIT) compiler assistance is presented, which can free objects explicitly by inserting the “free” instructions in compilation time. Combined with the merits of automatic and explicit memory management, the burden of both programmer and GC is reduced, and the utilization of memory space is promoted. It supports explicit object operation, and reuses these object spaces, which improves the operating efficiency of Java applications. Experimental results show this design scheme is feasible.

  • Networks and Communications
  • LIU Quan; REN Ping
    Computer Engineering. 2009, 35(10): 89-91. https://doi.org/10.3969/j.issn.1000-3428.2009.10.029
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    With the development of intelligent building control technology, this paper analyses feasibility and necessity of the wireless network technology used in the building field control layer. A wireless Ad Hoc network scheme based on logic token ring is proposed, which adopts polling mechanism and distributed control method, realizing a certain QoS guarantee in MAC layer. The key technologies to realize the wireless network are researched and the design scheme of wireless master station is provided.

  • CHEN Qin; FAN Wen-tao; ZHANG Min
    Computer Engineering. 2009, 35(10): 92-94. https://doi.org/10.3969/j.issn.1000-3428.2009.10.030
    Abstract ( )   Knowledge map   Save
    In Ad Hoc network, broadcasting by flooding results in broadcast storm problem. This paper proposes a new distributed Heuristic approximation algorithm for Minimum Connected Dominating Set(HMCDS), which includes constructing Maximum Independent Set(MIS), introducing the concept of effective degree, and using of the greedy strategy of choosing dominator node through nodes’ information of effective degree. Experimental results show that the size of Connected Dominating Set(CDS) achieved by using HMCDS is 7.6opt+1.4, time complexity is O(△2) and message complexity is O(n), which are better than similar algorithms.

  • LIU Rui-dong; AN Ke; ZHANG Shuo
    Computer Engineering. 2009, 35(10): 95-97. https://doi.org/10.3969/j.issn.1000-3428.2009.10.031
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper analyzes the problem of stochastic test traffic generating, concludes the generating expressions of stochastic test traffic. In the process of concluding, the paper uses GI/G/m/∞/FCFS multiclass open queuing network model to describe it, and gives a new formula for the variation coefficient of the interdeparture time, which controls the latency to make test traffic fit several probability. This paper applies it on the network test system with multi-core and multi-threading processor. Test results show the methodology is available and valid.
  • JIN Guo-ping; ZHONG Hua; ZHENG Lin-hua
    Computer Engineering. 2009, 35(10): 98-101. https://doi.org/10.3969/j.issn.1000-3428.2009.10.032
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Because Filtered Multi-Tone(FMT) systems has a complicated structure with an adaptive equalizing technology and low efficiency with channel estimations using pilots in time domain, this paper analyzes a signal in one subchannel and presents a new algorithm for channel estimation in FMT frequency domain. The algorithm selects some pilot subchannels and inserts the pilot sequence in them. Discrete Fourier Transform(DFT) of channel is gained with signals in pilot subchannels at the receiver. Theory analysis and simulation experiment show that the algorithm has less BER and does well in anti-frequency-offset.
  • ZHOU Lai-xiu; DENG Shu-guang; HU Sai-chun; YANG Bing
    Computer Engineering. 2009, 35(10): 101-103. https://doi.org/10.3969/j.issn.1000-3428.2009.10.033
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the deficiencies in the spectrum access scheme which is on the basis of the system of concession mechanism(BCM), this paper proposes a new dynamic one which is based on Minimizing Interference and Maximizing Demand(MIMD), and gives out the corresponding MIMD and Dynamic Spectrum Access(MIMD-DSA) algorithm. The proposed algorithm makes the cognitive user can select candidate access spectrum through the study of former spectrum access experience, and when the primary user appears, the cognitive user will handoff to these candidate spectrums through MIMD-DSA algorithm. Simulation and analysis results show that this scheme can further improve the efficiency of spectrum compared with the BCM scheme.

  • LI Ya-qing; LI La-yuan
    Computer Engineering. 2009, 35(10): 104-106. https://doi.org/10.3969/j.issn.1000-3428.2009.10.034
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the insufficiency of Low Energy Adaptive Clustering Hierarchy(LEACH) routing protocol that cluster-head nodes distribution is uneven in the space and cluster-head nodes consume excessive energy in the process of long-distance data transmission, this paper proposes an improved LEACH routing protocol¬¬ named LEACH-ZMH, which adopts the methods of cluster-head selection based on zone and multiple hop data transmission among clusters. The correctness proof and complexity analysis of LEACH-ZMH are given. Simulation by NS2 shows that the protocol extends the survival time of the network and performs better than LEACH protocol.
  • ZHONG Huai-dong; XU Kai; HOU Liu-ying
    Computer Engineering. 2009, 35(10): 107-108. https://doi.org/10.3969/j.issn.1000-3428.2009.10.035
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to increase the validity of uplink power control in Ka band satellite communication(30 GHz/20 GHz), an algorithm of uplink adaptive power control is presented. The method based on the Autoregressive Moving Average(ARMA) model can predict the rain attenuation of uplink from the rain attenuation of downlink measured and improve the precision of power control. Simulation results show that better compensation effects for rain attenuation can be achieved.
  • Security Technology
  • ZHAO Yi-bo; ZOU Heng-ming
    Computer Engineering. 2009, 35(10): 109-111. https://doi.org/10.3969/j.issn.1000-3428.2009.10.036
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the analysis of packet filtering techniques and current optimization algorithms, this paper proposes a new filtering-rule structure model and an adaptive optimization strategy that aims to enhance the performance for packet filtering firewalls. A series of trails on performance evaluation prove the effectiveness and usability of the special strategy.

  • REN Xin; LI Tao; HU Xiao-qin
    Computer Engineering. 2009, 35(10): 112-114. https://doi.org/10.3969/j.issn.1000-3428.2009.10.037
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A remote File Backup and Recover System(FBRS) is presented and realized. Through adding a system snapshot for the backup file on FBRS client, it determines whether the file is updated, computes the difference and sends the result of difference compute(difference file) to the FBRS server, the FBRS server playback the difference file, the remote file synchronization is realized. Test results show that compared to rsync, the system can prominent reduce the network bandwidth consumption.
  • GAO Da-peng; YU Shi-cai; YAN Wen-zhi
    Computer Engineering. 2009, 35(10): 115-117. https://doi.org/10.3969/j.issn.1000-3428.2009.10.038
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the current research on improving the Compressed Edge Fragment Sampling(CEFS) algorithm of Savage, the relations among the distance of the attacking path, the statistics on the traffic of routers, marking probability are analyzed. A new approach of composed packet marking method is proposed. In the new proposal the convergence of mathematic is optimized, computational complexity and the false positive alarm for the victim to reconstruct the attack graph is reduced, a victim can construct major attacking path in minimum time. The method can be used in tracking DDoS attacks of multi-source by establishing a simulated test environment and experiment analysis.
  • ZUO Li-ming; JIANG Zhao-feng; TANG Peng-zhi
    Computer Engineering. 2009, 35(10): 118-120. https://doi.org/10.3969/j.issn.1000-3428.2009.10.039
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Rootkit is a program or a set of programs that an intruder uses to hide her presence on a computer system and to allow access to the computer system. This paper analyses the main concealing techniques of Windows Rootkits, including DKOM and Hook, inner Windows system and points out the limitation of these single detection method. An integrated detection method is proposed to detect Rootkits. The main idea and implementation steps are presented. Experimental result shows that it owns satisfied detection effect, and can detect most actions of Rootkit.
  • WANG Ying-hui
    Computer Engineering. 2009, 35(10): 121-125.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Few security factors are taken into account in clustering traditionally and impact on network performance is always ignored. This paper proposes a novel approach for trust relation based clustering in Ad Hoc network. The approach is based on spread activation model, which is an organization structure for human long-term memory. This scheme can partition the whole network into many clusters according to limited local knowledge automatically. Simulation results show the accuracy of the clustering approach is very closed to the concentrating method.

  • CAO Man-cheng;
    Computer Engineering. 2009, 35(10): 126-128. https://doi.org/10.3969/j.issn.1000-3428.2009.10.041
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    By extending strand spaces model, it has ability of analyzing the complex security protocol. By the extended strand spaces model, this paper analyzes the 4-way handshake protocol in IEEE 802.11i, and proofs the 4-way handshake protocol in IEEE 802.11i can achieve the goal of the authentication and confidentiality. For the analysis of the availability, it needs continue to research strand spaces model.

  • WANG Liang; GUO Ya-jun;
    Computer Engineering. 2009, 35(10): 129-131. https://doi.org/10.3969/j.issn.1000-3428.2009.10.042
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For the problem of security in P2P e-commerce system, this paper provides a novel reputation-based trust model. By introducing many comprehensive trust factors in computing trust level and improving the calculation methods of the local reputation and global reputation, this model can not only accurately reflect the node’s trust level, but also reduce the time complexity in computing trust level. Experimental results show that the trust model can improve the rate of successful transaction compared to the existing trust models, and can be effectively applied to the P2P e-commerce system.

  • TAN Le; LI Jing-jing; LONG Dong-yang
    Computer Engineering. 2009, 35(10): 132-134. https://doi.org/10.3969/j.issn.1000-3428.2009.10.043
    Abstract ( ) Download PDF ( )   Knowledge map   Save

    Combined public key and threshold cryptography are applied to key management for Mobile Ad Hoc Network(MANET) in this paper. The Key Distribution Center(KDC) is used for the initialization of the whole network. In the operation phase, a scheme is proposed to dynamically change the number of server nodes and the threshold value. The method about how to deal with the new node addition and the node eviction is given. The key management scheme is secure, efficient and flexible, so it is especially suitable for the characteristics of MANET.

  • YANG Shu-guo;
    Computer Engineering. 2009, 35(10): 135-138. https://doi.org/10.3969/j.issn.1000-3428.2009.10.044
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a novel chaotic scrambling and encryption method of image. It uses two coupled chaotic maps to generate a sequence of chaotic pairs, disorder the original image with the new pixel address codes which are produced by these pairs and gain disordered image, transforms the disordered image by Discrete Cosine Transformation(DCT), and change every DCT coefficient of image with the aid of a chaotic sequence in DCT domain to complete the encryption of image. The process of decryption and the anti-scrambling is the inverse of the process above. Simulation experimental results show that the method is feasible, security and easy to operate.
  • LU Ming; WANG Xiao-li; XIE Li
    Computer Engineering. 2009, 35(10): 139-141. https://doi.org/10.3969/j.issn.1000-3428.2009.10.045
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Due to current address-space randomization techniques having only limited timings to deploy randomization, this paper proposes a new method to re-randomize the address space at runtime. By modifying the dynamic linker, this new method can randomize some kind of dynamic shared libraries in address space of target process without restarting. The result of analysis shows that the new method can reduce the probability of successful attack from O(pT) to .
  • ZHAO Li; CUI Du-wu
    Computer Engineering. 2009, 35(10): 142-144. https://doi.org/10.3969/j.issn.1000-3428.2009.10.046
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A text watermark algorithm based on the tone of Chinese characters is proposed. The text watermark, with the modification of the characters value by transformations, can be embedded into the area by the marked codes. The marked codes are decided by the characteristic of the document. The watermark capacity decided by the amount of marked codes can be changed freely. The whole article can be divided into many parts, the embedding and extraction of the text watermark can be done independently in each. The complexity can be reduced in this way.
  • CAO Li; HUANG Hai-bin
    Computer Engineering. 2009, 35(10): 145-146. https://doi.org/10.3969/j.issn.1000-3428.2009.10.047
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the 4-way handshaking protocol defections of the new-generation wireless network security standards 802.11i and the remaining attacks probably exist, this paper studies improved scheme of TPTK technology and re-Nonce. By analyzing the security vulnerabilities of two improved schemes, a new improved design based on digital envelope technology is provided, and it is analyzed and verified.
  • SHEN Wei-jun; ZHAO Yi-ming; ZHAI Yao; QIAN Yi
    Computer Engineering. 2009, 35(10): 147-149. https://doi.org/10.3969/j.issn.1000-3428.2009.10.048
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Some security problems existing in AIK keys generation protocol in trusted computing, this paper presents an improved AIK keys generation protocol. The improved protocol is constructed on the basis of non-malleable zero-knowledge protocol and adaptive chosen cipher text attack resistant cryptographic scheme. As a result, the improved protocol is proved to be non-malleable. Compared with the original one, the improved protocol has high security and can solve the existing security problems.

  • SUN Lei; DAI Zi-shan
    Computer Engineering. 2009, 35(10): 150-151. https://doi.org/10.3969/j.issn.1000-3428.2009.10.049
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the analysis of existing key management model to Ad Hoc networks, a key management scheme based on certificate-less cryptography is proposed, which employs the secret sharing technique to distribute system key among a pre-selected set of nodes, which offers a collaborative private-key-generator service. The scheme can strongly overcome the key escrow and resist coalition of adversaries. The construction method ensures secure and efficient network-wide key update by single broadcast. The analysis and simulation results show the scheme is secure and effective.
  • LI He-ling; QI Wen-feng
    Computer Engineering. 2009, 35(10): 152-154. https://doi.org/10.3969/j.issn.1000-3428.2009.10.050
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper studies the k-error linear complexity of binary sequences with period 2n. It is well known that the linear complexity of binary sequences with period 2n is strictly larger than 2n1. Form the entire stability of binary periodic sequences, the minimal value k is given for which there are at least half of the sequences with period 2n have k-error linear complexity not larger than 2n1. The minimal value k is studied for balanced sequences and imbalanced sequences with period 2n respectively.
  • ZHAO Xiao-long; ZHANG Yu-sen; YUAN Feng
    Computer Engineering. 2009, 35(10): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2009.10.051
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The concept of organization domain is introduced to describe the hierarchical structure of the enterprise organization. Based on the concept, the elements of access control are redefined and an Organization-Structure Oriented Access Control(OSOAC) model is proposed. The hierarchical OSOAC model and constrained OSOAC model are drawn by extended the Core OSOAC model. Contrast to RBAC model, there are fewer roles and permission assignment relations in OSOAC model, which reduce the privilege-management complexity in a large access control system.
  • TIAN You-liang; PENG Chang-gen
    Computer Engineering. 2009, 35(10): 158-161. https://doi.org/10.3969/j.issn.1000-3428.2009.10.052
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A knowledge commitment scheme is designed by making use of bilinear pairings, it satisfies hiding and binding of commitment. Using the scheme, a new secret sharing scheme is constructed. This scheme is a verifiable(t, n) threshold secret sharing scheme that its shares can be updated. Based on the threshold secret sharing, a verifiable(t, n) threshold signature scheme is structured. This scheme is forward secure, and shares of parties can be updated and need not compute the inverse element.

  • GU Dong-liang; ZHOU Jian; CHENG Ke-qin
    Computer Engineering. 2009, 35(10): 162-163. https://doi.org/10.3969/j.issn.1000-3428.2009.10.053
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper presents a method of limiting connections. The method uses extension of Netfilter/Iptables system to create a Netfilter/Iptables module, which can limit TCP and UDP connections separately. The TCP connections limit algorithm of this module uses characteristics of TCP connection, while UDP uses time tag. By using this module, it can limit parallel connections of client PC conveniently and effectively.

  • QU Xin-nan; SUN Qiu-yan
    Computer Engineering. 2009, 35(10): 164-167. https://doi.org/10.3969/j.issn.1000-3428.2009.10.054
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    There appears a lot of scrambling methods, but no one is the best. In order to measure the scrambling degree of these algorithms to different images better, this paper proposes a new method for accessing the image scrambling degree, which utilities the favorable performance of Discrete Cosine Transform(DCT) coefficients and the feature of masking of human vision system. Experiments show that the method correlates with subjective assessment and its results can reflect scrambling effect well of the same image and different images.

  • HU Jian-jun
    Computer Engineering. 2009, 35(10): 168-169. https://doi.org/10.3969/j.issn.1000-3428.2009.10.055
    Abstract ( )   Knowledge map   Save
    Cryptographic protocol is specified as to put aside minor differences so as to seek common ground. Assuring protocol correctness, a new efficient method that servers challenge-response as analysis unit of protocol is proposed. The analysis example on Needham-Schroeder protocol and Needham-Schroeder-Lowe protocol shows that the method is feasible and availability.
  • Artificial Intelligence and Recognition Technology
  • JIA Shi-jie; HUANG Qing-song; MA Shi-xia
    Computer Engineering. 2009, 35(10): 170-172. https://doi.org/10.3969/j.issn.1000-3428.2009.10.056
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The Case-Based Reasoning(CBR) intelligent recommendation system is the important part of scientific instrument shared network. Through clustering the case database in terms of grid, this paper designs a retrieval strategy on the basis of the non-isomorphic case database and also carries it out. It analyzes the principles of case database grid partition and case clustering, and deeply discusses the case clustering algorithm as well as the case retrieval strategy on the basis of clustering. The results of an experiment show that this method can efficiently reduce case retrieval time and enhance case database maintainability.
  • GUO Cong-li; ZHU Li; LI Xiang
    Computer Engineering. 2009, 35(10): 173-175. https://doi.org/10.3969/j.issn.1000-3428.2009.10.057
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper applies the Ant Colony Algorithm(ACA) to the optimization of multi-join. It introduces basic principles and working process of ACA, then builds a multi-join query optimization model based on ACA. With the method proposed by this paper, a high quality solution to the multi-join queries problems can be obtained.
  • LIANG Jun; CHEN Xiao-bo; CHENG Xian-yi; LI Xiao-yan
    Computer Engineering. 2009, 35(10): 176-178. https://doi.org/10.3969/j.issn.1000-3428.2009.10.058
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the shortcomings of distance between vehicles measurement as the only determining factor in car rear-end alarm system, a Modeling of Rear-end Warning based on MAS and Behavior(MRWMB) is proposed. Bayes decision theory is utilized to prevent collision happened real time by calculating the probability of collision. The effectiveness and robustness of the model are confirmed by the simulation result and its average performance of warning is improved by around ten percent.
  • WU Guo-xi; ZHANG Bo-ping; HU Zi-yi
    Computer Engineering. 2009, 35(10): 179-181. https://doi.org/10.3969/j.issn.1000-3428.2009.10.059
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper applies immune arithmetic and Agent idea to realize decision support, and establishes a decision support system for urban river water pollution control based on immune Agent. This system solves the problem that decision support system can’t acclimatize itself to the dynamic environment, ensures that decision support system faces to question region, and increase its intelligence and self-adaptablity. Experimental results show that Agent decision support method by the way of AHP is feasible.

  • PENG Xiao-ming; HE Yan-xiang; ZHU Bing-jian
    Computer Engineering. 2009, 35(10): 182-187. https://doi.org/10.3969/j.issn.1000-3428.2009.10.060
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to find and select the appropriate Web services meeting the requirements of users efficiently in the process of Web services composition, this paper uses multi-objective optimization based on Ant Colony Algorithm(ACA) to achieve the users’ requirement of the Quality of Service(QoS) composition. According to the properties of Web services, the appropriate Web service is selected and the Pareto optimal solutions set is gained. One or more solutions are selected as the optimal solution from the Pareto optimal solutions set, and the decision project is formed. It is compared with the corresponding research from theory and experience.
  • ZHANG Yan; TANG Zhen-min; LI Yan-ping
    Computer Engineering. 2009, 35(10): 188-189. https://doi.org/10.3969/j.issn.1000-3428.2009.10.061
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In this paper, a novel method of extracting speaker character is proposed, which is based on the single word. Compared with conventional methods, this method aims at interrelated frame, effectively finding multi-representative frames in single word utterance, and puts together the character vectors of these frames to constitute the character vector of this single word, which is adopted to calculate the codebook and model matching in training and recognition process. Simulation experiment indicates that this method can acquire higher recognition rate in Speaker Recognition(SR) system.

  • LI Zheng-yi; ZHU Yi-dan; ZHAO Long
    Computer Engineering. 2009, 35(10): 190-192. https://doi.org/10.3969/j.issn.1000-3428.2009.10.062
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a supervised direct locality preserving projection algorithm for image recognition. This algorithm solves locality preserving projection problem via simultaneous diagonallization combined with samples’ information, and can avoid the singularity of the matrices. Experimental results on the ORL face database show that this algorithm is more powerful than PCA and PCA+LPP for face recognition.
  • ZHAO Xue-feng; YUN Chao; LIU Xiang-quan; WANG Wei
    Computer Engineering. 2009, 35(10): 193-195. https://doi.org/10.3969/j.issn.1000-3428.2009.10.063
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Auto-pharmacy is the logistic system to implement the automation of medicine-input, medicine-store and medicine-output. After analyzing the constraints and objective function of auto-pharmacy scheduling policy, the optimization problem based on section and location assignment policy is studied and the corresponding mathematic model is built. Genetic algorithm is also adopted to solve the optimization. Simulation experimental results show this strategy is effective.

  • LIU Feng; GE Lin-dong; WU Ye-jin; LIU Shi-gang
    Computer Engineering. 2009, 35(10): 196-197. https://doi.org/10.3969/j.issn.1000-3428.2009.10.064
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the problem of convergence to local minima in traditional blind equalization algorithm, a new blind equalization algorithm based on artificial immune network is presented. The coefficient vector of a blind equalizer is regarded as the antibodies and the optimal solutions can be obtained by replication, mutation and suppression. Simulation experimental results show this algorithm is effective.

  • WANG Fei
    Computer Engineering. 2009, 35(10): 198-200. https://doi.org/10.3969/j.issn.1000-3428.2009.10.065
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Typical optimized retrieval procedure methods such as data fusion and relevance feedback-based query expansion are introduced. While data fusion improves retrieval performance by merging multiple retrieval results, relevance feedback revises user query according to previous retrieval result and runs the new query to improve retrieval performance. On the basis of this, a novel optimized retrieval procedure method called HQD is presented, which selects top-ranked documents from the relevance feedback result, runs these documents as surrogate queries, and merges the retrieval results using a sum cosine measure. Experimental results show this method is effective.
  • LIU Jin-ling
    Computer Engineering. 2009, 35(10): 201-202. https://doi.org/10.3969/j.issn.1000-3428.2009.10.066
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Existing data clustering method lacks considering of latent similar information existing among words, and it leads to unsatisfactory clustering result. Aiming at Chinese short message text clustering, this paper proposes a clustering algorithm based on semantic. It offers Chinese concept, and the measuring methods to calculate the similarity degree about words and Chinese short message text. It completes the clustering of Chinese short messages text through fission downwards and mergence of twos upwards. Experimental results show that this algorithm has better clustering quality than traditional algorithm.
  • Graph and Image Processing
  • WANG Yi-cong; CHEN Ken
    Computer Engineering. 2009, 35(10): 203-205. https://doi.org/10.3969/j.issn.1000-3428.2009.10.067
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the problem of segmenting the touching anomalous objects in an image, this paper proposes a method based on saddle-point detection using Hessian matrix. The image is converted to its 3D topographic counterpart by sequential erosion, followed by searching the saddle-point utilizing Hessian matrix determination approach. The segmentation is performed at the identified saddle-point by tracking the maximal gradient path. Compared with other conventional segmentation algorithms, this method is more practical for implementation, and shows its superiority in execution speed.
  • ZHANG Hui-xin; QU Xiao-bo; YAN Jing-wen
    Computer Engineering. 2009, 35(10): 206-208. https://doi.org/10.3969/j.issn.1000-3428.2009.10.068
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Classical interpolation method based on ramp edge model considers all the edges as strong edges, which results in weak edges’ distortion. Aiming at this problem, a New Image Interpolation method Based on Ramp EDge model(NIIBRED) is proposed, which uses different methods for strong edges and weak edges. This method considers that the edges generated in the enlarged image do not have the same width, and reconstructs the enlarged image. Experimental results show that NIIBRED can make the enlarged image’s edges more natural and clearer, and obtain better texture effects.

  • XU Ling-ling; XIAO Jin-sheng; YI Ben-shun; LOU Li-jun
    Computer Engineering. 2009, 35(10): 209-210. https://doi.org/10.3969/j.issn.1000-3428.2009.10.069
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The complex computing restricts the application of image segmentation method based on Chan-Vese(C-V) level set model. In order to improve the speed of image segmentation, this paper presents a new level set initialization method on C-V model. After a simple iterative, the outline of objects can be separated out. Experiments show that the method is simple and efficient, with good separation effects.

  • QIAO Wei-wei; WU Cheng-mao
    Computer Engineering. 2009, 35(10): 211-213. https://doi.org/10.3969/j.issn.1000-3428.2009.10.070
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a weighting Otsu’s segmentation method based on gray probability of image from the point of view of information divergence. The weighting method based on gray probability of image is extended to obtain a generalized weighting Otsu’s segmentation method. An explanation of this new method is provided based on the fuzzy energy theory. Experimental results show that this new method is feasible, and it can help to avoid the possible inconsistent problem between image segmentation output and the real target when using traditional Otsu’s segmentation method. It provides a useful supplement to the existing Otsu’s segmentation method.
  • Multimedia Technology and Application
  • LI Yan-cheng; CUI Hui-juan; TANG Kun
    Computer Engineering. 2009, 35(10): 214-216. https://doi.org/10.3969/j.issn.1000-3428.2009.10.071
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the performance decline problem of voice activity detection under low signal-to-noise and noise change circumstances, this paper proposes a new parameter updating and value obtaining algorithm. This algorithm uses Laplacian-Gaussian mixed model, a new, efficient VAD algorithm using Likelihood Ratio Test(LRT) is proposed. The parameters of the model are estimated from noisy voice. The estimated noise power parameter is smoothed during the gaps of voice syllables. Experimental results indicate that the detection rate of this algorithm is above 95% when SNR is -5 dB. This algorithm achieves predominant tracking performance.

  • LU Guo-qing; LI Jun-li; CHEN Gang; ZHANG Ying; MAN Jia-ju
    Computer Engineering. 2009, 35(10): 217-219. https://doi.org/10.3969/j.issn.1000-3428.2009.10.072
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the the disvantage that the video quality assessment based on structural distortion measurement can not apply directly on the video field and think over HVS, this paper proposes a method of video quality assessment based on visual regions-of-interest. It thinks about HVS, the structural distortion measurement and motion information. Experimental results show that the method is better than the method based on PSNR, MSSIM and ESSIM on the compress losing, smooth losing.
  • LIN Shu-jing; CHEN Jian
    Computer Engineering. 2009, 35(10): 220-223. https://doi.org/10.3969/j.issn.1000-3428.2009.10.073
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper presents a block motion estimation algorithm named Novel Oriented Diamond-Arc Search(NODAS) using small cross-diamond-arc search pattern. According to the characteristic of the center-based motion vector distribution for the real-world video sequence, NODAS employs small cross pattern extended oriented diamond search pattern to refine the central area search and employs diamond-arc search pattern for large motion vector. Experimental results indicate that NODAS algorithm can reduce the number of search points to improve the search speed with the similar search precision, and it does well in stationary and large motion search.
  • WANG Ying-kun; XU Bo-qing; YANG Hua
    Computer Engineering. 2009, 35(10): 224-225. https://doi.org/10.3969/j.issn.1000-3428.2009.10.074
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a novel motion search algorithm. This algorithm sorts the video and search pattern by motion feature respectively, and codes the video with corresponding search pattern adaptively. In order to accelerate the coding speed, it accepts hierarchical search strategy and the early termination strategy in the algorithm. Experimental results show that the execute time of the algorithm is less than full search algorithm with similar visual quality and bit rate. The method can be applied to various video sequences with different motion feature and is superior to conditional search algorithm, such as NTSS, DS and HEXS in both encoding speed and encoding quality.
  • Engineer Application Technology and Realization
  • LIU Ming-xing; GONG Liang; YANG Yu-pu
    Computer Engineering. 2009, 35(10): 226-228. https://doi.org/10.3969/j.issn.1000-3428.2009.10.075
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper introduces an application of IEEE 1394 bus in servo control system. It designs a 1394 front-end communication module to transform the data. The front-end module, in which a DSP processor is used to control the corresponding IEEE 1394 chip, realizes the high speed IEEE 1394 bus interface between CNC and servo units. Both the hardware and software design of 1394 front-end communication module are described. Communication experiments, between 1394 front-end communication module, host computer and motion controller, validate the feasibility of the application of IEEE 1394 bus in servo control system.
  • ZHANG Xiao-feng; BAI Guo-qiang; CHEN Hong-yi
    Computer Engineering. 2009, 35(10): 229-231. https://doi.org/10.3969/j.issn.1000-3428.2009.10.076
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper introduces a ring oscillator based True Random Number Generator(TRNG) for network security co-processor. To obtain better randomicity, the circuit utilizes a fixed frequency clock to sample the output of a frequency variable high speed ring oscillator. Inter-stage feedback ring is introduced to control the frequency of the high speed ring oscillator to accumulate the phase noise. Start-up circuit is designed not only to make the ring oscillator much easier to oscillate, but also to reduce the power dissipation by introducing enable signal. TRNG is designed under CMOS 0.18 μm standard process. Hspice_RF is used to perform jitter simulation to acquire optimum parameters. Simulation results show that random bit stream can pass statistical test for randomness under 1 Gb/s sampling frequency.
  • LI Fei; WU Nai-qi
    Computer Engineering. 2009, 35(10): 232-234. https://doi.org/10.3969/j.issn.1000-3428.2009.10.077
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    With wafer residency time constraints in cluster tools for semiconductor fabrication, feasibility of schedule and control can not be checked analytically. A new method based on simulation is presented, and a virtual single-arm cluster tool for controller testing is developed by using eM-Plant. It is a parameterized model which provides an effective tool for researchers to study the control problem of cluster tools, and for engineers to check feasibility of a schedule for them.
  • WU Yu-xiang; ZHOU Dong-xia; LIN Jin-yun
    Computer Engineering. 2009, 35(10): 235-237. https://doi.org/10.3969/j.issn.1000-3428.2009.10.078
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The hardware and software design platform of embedded soft PLC is presented. Embedded soft PLC system for industrial control is developed by the techniques of ladder diagram, hardware interface mapping and modular design. This system is composed of development system and operating system. The development system translates the programs based on graphics language into target code, and the operating system loads the target code and executes command based on the code to control the system.

  • LIU Hua-wei; HE Li; HUANG Guo-rong
    Computer Engineering. 2009, 35(10): 238-239. https://doi.org/10.3969/j.issn.1000-3428.2009.10.079
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the problem that Air Data System(ADS) can not achieve dynamic joint-trial with avionics because of its failure in normal parameter output in ground static state, this paper proposes a scheme which develops an ADS simulator to realize dynamic joint-trial. It uses the techniques such as multithreading and precise timer to improve simulator’s real-time performance. Experiment proves that the simulator can satisfy the requirement of dynamic joint-trial.
  • Developmental Research
  • XU Chang-long; CAI Shi-min; ZHOU Pei-ling
    Computer Engineering. 2009, 35(10): 240-242. https://doi.org/10.3969/j.issn.1000-3428.2009.10.080
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The changing trends of binary sequences are analysed with AR model(the autoregressive model), to obtain the linear model characteristics. And through a limited order of conditional probability analysis of the binary sequences, the stock index has a remarkable structural feature. This paper is from another perspective to reveal that the financial markets are not completely effective. By comparing the structural characteristics of the stock index of the developing and developed markets, it finds that the non-rational investment behavior is in the immature emergent financial markets.

  • FENG Juan; SHI Hao-shan; LI Shi
    Computer Engineering. 2009, 35(10): 243-245. https://doi.org/10.3969/j.issn.1000-3428.2009.10.081
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to improve that automation of systems is low level in traditional object-oriented technology which is difficult to adapt to changes in the two aspects of demands and technology, this paper facilitates the development of products and the management of military enterprises, designs the digital management platform of military enterprises based on the model-driven. It uses the idea of model-driven design the overall framework of system and has the inference mechanism of ontology library and rules to implement the mutual transformation of models. The development and management of enterprise product are implemented, intelligently and digitally. The whole system and enterprise development’s synchronization is ensured.

  • CAO Zhen-hua; WANG Yi-huai; GE Qiang
    Computer Engineering. 2009, 35(10): 246-247. https://doi.org/10.3969/j.issn.1000-3428.2009.10.082
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The introduction of Computer Operating Properly(COP) in embedded system can guarantee the normal operation of system, and automatically come back to the normal operation from failure. It does not require special treatment or only to use simple memory recovery after COP reset will be able to bring the system back to the normal running. If system includes some special module such as USB module, the above methods can not work. Take a data acquisition system as a example, the failure mechanism about USB module are discussed, and a countermeasures based on register recovery is given, which can effectively rescue system’s similar paralys after COP reset.

  • SHEN Jin; ZHANG Wei; XIONG Peng
    Computer Engineering. 2009, 35(10): 248-250. https://doi.org/10.3969/j.issn.1000-3428.2009.10.083
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper studies Dedicated Short Range Communication(DSRC) protocol conformance test technology of On Board Unit(OBU) equipment, which is designed based on Chinese DSRC standard. Through research and analysis of the specialty of OBU equipment and Chinese DSRC standard, in accordance with ISO/IEC 9646 protocol conformance test standard, and combining with TTCN-3 testing technology, it proposes a complete solution which includes the design of Abstract Test Suite(ATS) and the test platform.
  • LUO Ru-bai; ZHOU Shi-sheng; ZHAO Jin-juan
    Computer Engineering. 2009, 35(10): 251-253. https://doi.org/10.3969/j.issn.1000-3428.2009.10.084
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To effectively integrate companies in printing production, it is necessary to set up a standard specification of information integration, which defines the content and format of data exchange among heterogeneous system. According to the needs, existing standards such as Job Definition Format (JDF), which based on eXtensible Markup Language (XML) and related technologies are presented. The characteristics of XML and the profile of JDF are expounded. JDF-based printing production information integration specification are analyzed. This paper develops a compatible JDF Agent using C++.
  • XU Hui-jie; ZHANG Yun-wei
    Computer Engineering. 2009, 35(10): 254-256. https://doi.org/10.3969/j.issn.1000-3428.2009.10.085
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    According to the structure and growing characteristic of underground stem-root of bamboo, a 3D modeling method based on the geometrical modelling is proposed. In this way, topology and geometrical structure of underground stem-root of bamboo are built, then the 3D geometrical structure of underground stem-roots of bamboo is dealed with by ‘Rendering’. Combined with this technique, using recursive algorithm and programming in the Visual C++, a system, which can simulate the growing process of underground stem-root of bamboo with verisimilitude, is established. Results prove that the proposed method is of good validity and feasibility.

  • WU Wei-he; HAO Ai-min; LI Zhi; WANG Wen-tao; YANG Yue-dong; WANG Li-jun
    Computer Engineering. 2009, 35(10): 257-258. https://doi.org/10.3969/j.issn.1000-3428.2009.10.086
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the characteristics that indirect illumination distribution is in all directions and lack of variation with the change of its orientation, this paper uses an array of lights to calculate their direct illumination which is accelerated with GPU hardware implementation, and achieves rapid global illumination simulation. Experimental results show that this method is faster than physical rendering method and with good visual effect.
  • NAN Chun-li; ZHANG Sheng-rui; NING Hang; YAN Bao-jie
    Computer Engineering. 2009, 35(10): 259-261. https://doi.org/10.3969/j.issn.1000-3428.2009.10.087
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the disadvantage of linear congruential method widely used in urban traffic system simulation software, this paper adopts graphic approximating and statistical testing methods to compare the random number generators that being used and being researched. According to the norm theorem, it presents 2-norm statistical test performance evaluation expression and error. Analysis results indicate that MT algorithm can achieve better performance in traffic simulation. Example gives a proof that MT algorithm approximates actual traffic situation better.
  • TANG Zi-yang; LIU Jin; ZHANG Ke-jun
    Computer Engineering. 2009, 35(10): 262-263. https://doi.org/10.3969/j.issn.1000-3428.2009.10.088
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    As the current short message business of mobile telephone is uncompetitive for its high cost and the limit within two people, this paper makes use of the comparatively strong ability of J2ME in net communication to construct a platform for multi-communication at lower cost. The J2ME/Servlet-based mobile telephone chat system is proposed. This paper presents the thinking and pivotal technology of putting the chat system into practice. Experimental results show the feasibility of the system.
  • ZHU Tao; LUO Shi-jian
    Computer Engineering. 2009, 35(10): 264-266. https://doi.org/10.3969/j.issn.1000-3428.2009.10.089
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper presents a novel real-time texture synthesis algorithm on large scale 3D physiognomy surface. The algorithm contains three stages. it projects the 3D surface onto 2D plane, gives every triangle grid a scale factor which describes what kind of texture to use, synthesizes texture over 2D plane using mip-mapped texture sample. Experiments show that this algorithm can produce very nice real-time results.
  • WANG Zhen-jiang
    Computer Engineering. 2009, 35(10): 267-269. https://doi.org/10.3969/j.issn.1000-3428.2009.10.090
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Value added service design quality depends on capability of mobile terminal and analysis of user information. This paper proposes a logical layers model of capability system, differenciates manufacture-based device capability and user based device capability, and defines corresponding management flow which covers profiling, validation, management and description. System architecture is proposed based on multiple existing technologies and protocols. Prototype study by merging capability system and streaming service verifies its effective supporting capability to the service design and personalization.

  • LI Xue-sen; LI Jun; XI Hong-sheng
    Computer Engineering. 2009, 35(10): 270-272. https://doi.org/10.3969/j.issn.1000-3428.2009.10.091
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Streaming media service providers needs to know the evaluation of a streaming media server to select the server, but there is no suitable performance evaluation method of streaming media server. This paper analyzes the main streaming media server evaluation index, and uses multi-attribute decision to establish an evaluation model. It tests the performance evaluation index of three streaming media servers, sorts them through the performance merits, thus chooses the right server.

  • ZHANGHANG Qian
    Computer Engineering. 2009, 35(10): 273-275. https://doi.org/10.3969/j.issn.1000-3428.2009.10.092
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For According to 2Dd SIMD architecture, this paper presents a low low-power schedule algorithm which combines compiler, instruction set and micro architecture’s support, and it can close idle components dynamically. This algorithm contains compiler optimizing 2D SIMD instructions., Power instructions sendinsg switch signals., The system receivinges and executes these signals and executing. It involves different methods for computing unit and memorydifferent function units separately and. It also involves localizepartition unit method. The result of eExperimentsal result on simulator shows that this algorithm will can save about 15% of the total system’s power consumption.
  • KONG De-yu; WANG Hao-chen; LIU Lu
    Computer Engineering. 2009, 35(10): 276-279. https://doi.org/10.3969/j.issn.1000-3428.2009.10.093
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the business process of large-sized transformer electrical design, this paper adopts the idea of Service-Oriented Analysis and Design(SOAD) to build a business process model for product design, and proposes the architecture of large-sized transformer designing integration platform and its solution. The large-sized transformer designing integration platform is developed using Web service technology and XML language, and it can solve the problem of information island occurring in product design process. The practical application of the platform in an enterprise shows that it can increase the efficiency of product design to more than ten times as before.
  • ZHOU Hui-ren; ZHENG Pi-e; WANG Song; LIU Chun-xia
    Computer Engineering. 2009, 35(10): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2009.10.094
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a financial crisis warning model, based on Least Squares Support Vector Machines(LS-SVM) of which related parameters is optimized through Particle Swarm Optimization(PSO). A case study based on financial data acquired from listed companies is carried out using the method proposed to detect the finance problem. It is shown that LS-SVM with parameters optimized by PSO, is simple and effective.
  • KANG Ling-yan; WANG Jian-lin; ZUO Ze-jun
    Computer Engineering. 2009, 35(10): 283-285. https://doi.org/10.3969/j.issn.1000-3428.2009.10.095
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Realizing the information integration from bottom process control level to application level has important significance in the process of enterprise integration automation. By studying the OPC XML-related technologies, an information integration method based on OPC-XML is proposed, the system architecture of the B/S mode is designed, and an independent OPC XML-DA server and its corresponding client are developed. When it is applied in petrochemical enterprises, the system implements the function of real-time access and remote detection to bottom layer data. It provides foundation for higher level system integration of the enterprise, and promotes the realization of enterprise integration automation.