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05 March 2008, Volume 34 Issue 5
    

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  • PAN Deng; ZHENG Ying-ping; LU Xiao-fang
    Computer Engineering. 2008, 34(5): 1-4. https://doi.org/10.3969/j.issn.1000-3428.2008.05.001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to avoid the congestion on the non-closed routes, the Vehicle Routing Problem(VRP) is studied with the ant colony algorithm. This paper presents the pointer marching strategy with the one-depth tree structure and the optimal algorithm for the related vehicle routing problem, which provides references for decision-making in traffic management and vehicle guiding. The simulation shows that the improved algorithm can relieve the congestion effectively with its ability to distinguish it.
  • LIU Bo; YANG Lu-ming; LEI Gang-yue
    Computer Engineering. 2008, 34(5): 5-7. https://doi.org/10.3969/j.issn.1000-3428.2008.05.002
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    Based on XML semi-structured characteristic and probabilistic query theory and antcolony algorithm, this paper gives a method to research for XML query which adds crossover operator and renews pheromone. It can not only choose data-query direction dynamic, but also avoid useless query. As a result, query range is widened and shrinkage efficiency is enhanced. At last, it is made sure by corresponding simulant test that the method can optimize XML query.
  • CAI Rong-tai; WANG Yan-jie
    Computer Engineering. 2008, 34(5): 8-10. https://doi.org/10.3969/j.issn.1000-3428.2008.05.003
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    A vector clustering algorithm is proposed to cope with the inefficacy of traditional clustering algorithms to vector data. The algorithm classifies data into clusters by minimizeing the distance of a datum to a vector. The clustered centers are vectors. According to the distributing character of the sparse signal, a sparse signal separation algorithm is proposed which estimates the mixture matrix based on the vector clustering algorithm, and separates the source signal using the estimated mixture matrix. The algorithm is simple in computation comparing with traditional separation algorithms. Experimental results show that the algorithm is effective in vector data clustering and sparse signal separation.
  • LI Feng; LI Da-xing
    Computer Engineering. 2008, 34(5): 11-13,2. https://doi.org/10.3969/j.issn.1000-3428.2008.05.004
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    This paper presents a new multisecret sharing threshold scheme. In the scheme, the dealer can manage any set of multiple secrets for sharing and participants can compute sub-secret for different secrets efficiently and securely. The scheme uses knowledge signature to against cheating by dealer and participants. It is demonstrated that this scheme is secure and efficient.
  • ZHOU Xiao-bin; FANG Yang-wang; XU Yong; WANG Ya-fei
    Computer Engineering. 2008, 34(5): 14-16,1. https://doi.org/10.3969/j.issn.1000-3428.2008.05.005
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    Based on key value GALT for the new standard IEEE1516 of HLA, the important significance of GALT in time management for HLA is discussed. The realization of GALT in the general time advancing algorithm and the reason for deadlock are analyzed, four sufficiency conditions for deadlock in the HLA time advancing, such as mutex condition, request holding condition, non-deprive condition and loop waiting condition, are researched and proved. The conception of dynamic slide model is put forward, and a non-deadlock time management algorithm based on dynamic slide model is designed. Finally, the new arithmetic for setting the reasonable value of Lookahead reasonably is analyzed.
  • YUAN Er-ming; CAI Xiao-qiang; TU Feng-sheng
    Computer Engineering. 2008, 34(5): 17-19. https://doi.org/10.3969/j.issn.1000-3428.2008.05.006
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    Travel networks are stochastic, time-varying. A time constraint(repeated sequence of time-windows)network model is proposed to simulate the operations of traffic-light control. In each time-window, only the car in specified routes is allowed to pass (green light) and others and not allowed (red light). In order to get the condition of car in front of intersection, this paper gives a function of time-windows, and gets the shortest path of signal traffic network with time-windows and offsets between intersections. A mixed algorithm combining the SDOT algorithm and genetic algorithm is designed to solve the problem. The paper simulates a four-intersection traffic network, result shows the effectiveness of the algorithm.
  • TANG Lei; ZHAO Chun-xia; WANG Hong-nan; SHAO Wen-ze
    Computer Engineering. 2008, 34(5): 20-21,3. https://doi.org/10.3969/j.issn.1000-3428.2008.05.007
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    A novel approach based on 3D terrain model is proposed to detect pavement cracks. A 2D pavement surface image is mapped to a 3D spatial surface, and the cracks that are difficult to describe in 2D surface can be regarded well as valleys in it. Then by analyzing the characteristics of valley space curvatures, the valleys are detected. As a result, the majority of crack information is detected successfully.
  • LI Lin-hai; YU Hong-yi; HU Han-ying
    Computer Engineering. 2008, 34(5): 22-24. https://doi.org/10.3969/j.issn.1000-3428.2008.05.008
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    This paper proposes a novel algorithm which uses the Kalman filtering based on Clarke’s model to track the Multiple-Input Multiple-Output(MIMO) time-varying multi-path fading channel. The channel transport function approximates the square root of the spectrum density, and a state-space model for the fading channel can be built based on the channel transport function. Combining the prior information of the time-varying fading channel power spectral density, MIMO channel state-space model can be obtained. Theoretical analysis and simulations show the algorithm is effective for the estimation of the fading channel when the performance of the channel estimation is presented in terms of the Mean-Square Error(MSE).

  • MIAO Zhi-min; DING Li; ZHAO Lu-wen; CHEN Yan-de; HU Gu-yu
    Computer Engineering. 2008, 34(5): 25-27,3. https://doi.org/10.3969/j.issn.1000-3428.2008.05.009
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    Network failures may result in an immediate feedback to the network topology. There’s a close relationship between network restoration and the network topology. This paper analyzes the relationship between topo-information and the network survivability. Some existing classifications for network restoration are discussed. The arithmetic on topological graph theory applied in network restoration is proposed. This paper introduces and analyzes three types of arithmetic based on network topology: network partition arithmetic; restore path selecting arithmetic; P-Cycle arithmetic. The problems urgently to be solved in nowadays’ network restoration are analyzed.
  • ZHAO Yong; LIU Ji-qiang; HAN Zhen; SHEN Chang-xiang;
    Computer Engineering. 2008, 34(5): 28-30. https://doi.org/10.3969/j.issn.1000-3428.2008.05.010
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    As a way to defend information’s confidentiality and integrity, access control takes a quite important role in military system and commercial system. Workflow is splitted into several task units, and the inter relationship among tasks is formally described. This paper gives startup condition of the task instance, puts forward a new access control model based on task. Experimental results show that the model is effective.
  • FENG Zi-jun; XIAO Jun-hua; HU Wei-wu
    Computer Engineering. 2008, 34(5): 31-32,3. https://doi.org/10.3969/j.issn.1000-3428.2008.05.011
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    SoC design uses a lot of IP, and the verification of IP is the key of SoC design. CPU IP is used broadly, but it is difficult for verification. This paper introduces the methodology of godson-1 IP verification, describes the Godson-1 IP architecture briefly, which is low power and configurable IP, and the simulation platform of IP. It compares the Godson-1 IP verification methodology with traditional verification flow, and gives some suggestion for this platform. It shows Godson-1 IP verification is successful.
  • WEI Li; ZHOU Yue-zhi; XIA Nan
    Computer Engineering. 2008, 34(5): 33-35. https://doi.org/10.3969/j.issn.1000-3428.2008.05.012
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    This paper presents a new approach to allocate storage space in network storage system. It employs an Allocate on Demand(AoD) strategy, which can adjust real storage space used without modifying the logical volume size from a user’s perspective. It does not need to reconfigure file system size as in traditional methods if storage space is extended. It is much more flexible and scalable than traditional logical volume manager based methods. Primary results from the application in TransCom system show that the overhead is small and acceptable, it can meet the practical requirement.
  • FANG Zhi-bin; AN Xue-jun; HU Peng;
    Computer Engineering. 2008, 34(5): 36-38. https://doi.org/10.3969/j.issn.1000-3428.2008.05.013
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    Crossbar is the core logic of switch and chipset. This paper designs and implements a crossbar in multi-processor chipset, and the frequency of the crossbar is up to 100 MHz after placing and routing on FPGA platform. The delay and bandwidth of the crossbar is tested based on implementation, and some optimization strategies of the crossbar are proposed. The crossbar runs in multi-processor system composed by Godson 2E CPU.
  • WANG Jun; ZHENG Di; WU Quan-yuan
    Computer Engineering. 2008, 34(5): 39-41,5. https://doi.org/10.3969/j.issn.1000-3428.2008.05.014
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    Most of the current load balancing middleware adopt the per-object load monitoring granularity, and pay more attention to the balance among the different replicas of the same group. This paper discusses several key problems about how to improve the scalability of the load balancing middleware. Implementations and simulation results are given.
  • SUN Zhi-qiang; LI Xin-xin; XIE Hong-wei; LI Zheng-yi
    Computer Engineering. 2008, 34(5): 42-44. https://doi.org/10.3969/j.issn.1000-3428.2008.05.015
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    A concept of Operation Process Diagram OPD) is presented and the means of how to identify human error using OPD is discussed. The three basic modules of OPD are illustrated. And, the means of OPD construction and human error identification are presented. The error identification results are identical to the results from even tree. The OPD’s advantage over event tree and further research are discussed.
  • Software Technology and Database
  • ZOU Zhi-qiang; ; JIANG Nan; ZHANG Zheng;
    Computer Engineering. 2008, 34(5): 45-47,5. https://doi.org/10.3969/j.issn.1000-3428.2008.05.016
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    According to the characteristic of distributed Spatial Information Web Services(SIWS), this article outlines three strategies for improving quality of spatial services based on the developed practice of “national science data sharing project”. The strategies are as following: improving the framework of OGC (Open Geospatial Consortium) by introducing service-oriented architecture and metadata server; the introduction of aspect oriented programming into SIWS; the strategy for implementing Web Map Service (WMS) and spatial data buffer in spatial information domain. It presents the topological structure of our prototype and some corresponding test data to verify these three strategies.
  • WU Hong-li; YIN Bao-lin; XIANG Gang; ZHAO Xia
    Computer Engineering. 2008, 34(5): 48-50. https://doi.org/10.3969/j.issn.1000-3428.2008.05.017
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    How to solve the problem that business processes flexibly adapt to the changes of organization is the key idea that an enterprise improves its competitive power. This paper proposes a new flexible process modeling method based on extensible organization, and constructs a workflow model. In organization model, the new conception of sub-organization is introduced, which makes the organization model expansibility. In process model, all sub-organizations and workgroups are allowed to create sub-process independently and then reference it dynamical. Comparing with traditional workflow model with the capability of sub-processes definition, the method gains much more flexibility, and offers significant advantages in business processes modeling.
  • CHEN Xue-long; WANG Yan-zhang; LI Qiang
    Computer Engineering. 2008, 34(5): 51-53,5. https://doi.org/10.3969/j.issn.1000-3428.2008.05.018
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    The paper analyzes the limitation of the existing model construction methods. And the formal representation of decision problem is given. The construction method of decision model based on formalization representation of decision problem is proposed. The model construction process of the method is discussed in detail in terms of description model and problem model. An example of the method is given to prove the scientificity and the feasibility of the method.
  • ZHANG Hai-bo; FENG Shuo; ZHANG Huan; HUANG Zhao-hui
    Computer Engineering. 2008, 34(5): 54-56. https://doi.org/10.3969/j.issn.1000-3428.2008.05.019
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    This paper provides a software solution called SonD diskless Windows. The Windows simulates a virtual SCSI device in Windows2K/XP kernel mode to redirect local SCSI requests to network block device and performs data I/O with remote storage server. In this way, the computation and storage resources can be separated and then mapped dynamically to manage the storage resources unitedly and distribute the computation resources reasonable. In order to improve the performance of virtual SCSI device, a new request processing technique based on Windows hierarchical driver model called Hierarchical Request Filter(HRF) is presented. By exploiting this technique, the I/O performance of virtual network disk is improved.
  • WU Tao; ; SHANG Li; WANG Wei; CHEN Li-wei
    Computer Engineering. 2008, 34(5): 57-59. https://doi.org/10.3969/j.issn.1000-3428.2008.05.020
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    As the covering algorithm of forward neural networks design the network according to the training samples, its framework is easy to define and its performance is high. But the existence of noise samples may lead to some small covering domains, and these small domains increase the complexity and result in misrecognition. The support and confidence of a covering domain are defined and an algorithm of domains reduction is presented in this paper. Experimental results show that this algorithm can simplify the structure of the covering network and improve the stability of networks.
  • YU Yan-yan; LI Shao-zi
    Computer Engineering. 2008, 34(5): 60-62. https://doi.org/10.3969/j.issn.1000-3428.2008.05.021
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    Finding frequent itemset is a pivotal technology and stage in association rules mining application. Most studies adopt Apriori-like candidate set generation-and-test approach, but candidate set generation is still costly. This paper proposes an improved AprioriTid algorithm to improve the algorithmic executive efficiency, which is based on candidate set Lk address-mapping approach of Hash technology.
  • LIU Li-feng; WU Meng-da
    Computer Engineering. 2008, 34(5): 63-65. https://doi.org/10.3969/j.issn.1000-3428.2008.05.022
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    Association rules mining is an important research branch in data mining. However, most algorithms based on frequent item sets have to scan databases many times, which reduces extraction efficiency. This paper presents an algorithm to find all maximal frequent item sets quickly. The algorithm is based on concept lattice and it can certify all frequent item sets efficiently, which avoids calculating the redundant item sets and improves the extraction efficiency.
  • WANG Yang
    Computer Engineering. 2008, 34(5): 66-67,7. https://doi.org/10.3969/j.issn.1000-3428.2008.05.023
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    To deal with the problems of prematurity and low convergence speed when Genetic Algorithm(GA) is used for global optimization, a rough set attribute reduction algorithm based on niche GA is proposed. Based on crowding mechanism, punishing function is adopted to adjust individual fitness. It can advance global capability. Experimental results show the algorithm is effective. It can find different reductions of attribute in the information system and provide more information for decision support and data mining.
  • XU Shu-hua; JIANG Wen; HUANG Zhi-gang
    Computer Engineering. 2008, 34(5): 68-70. https://doi.org/10.3969/j.issn.1000-3428.2008.05.024
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    This paper proposes a greedy algorithm to arrange all Web service calls of a query into a pipelined execution plan that optimally exploits parallelism among Web services to minimize the query’s total running time. It solves the basic question: query optimization for select-project-join queries spanning multiple Web services. The optimization plan can be found in the presence of arbitrary precedence constraints among Web services.
  • ZHENG Sheng; YU Zhan-wu; LI Zhong-min
    Computer Engineering. 2008, 34(5): 71-73. https://doi.org/10.3969/j.issn.1000-3428.2008.05.025
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    The storage and management of massive terrain data is the key of large-scale terrain roaming. This paper proposes a distributed parallel mechanism based on object storage——Distributed Parallel Terrain Service System(DPTSS), which adopts self-rule storage object to store and manage terrain block data and realizes the division of control path and data path. Divided metadata cluster provides high-effective and high-available metadata service, and OSD cluster with parallel terrain data transmission provides high throughout and bandwidth. A prototype system for DPTSS is established. Experimental results show that DPTSS in lower TCO enables good terrain data distributed service.
  • JIN Bao-xuan
    Computer Engineering. 2008, 34(5): 74-76. https://doi.org/10.3969/j.issn.1000-3428.2008.05.026
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    Because grid is set up on the basis of services, it makes spatial database face the problems in grid environment such as how to provide corresponding database service, how to implement spatial data integration among heterogeneous databases system and spatial data interoperability, etc. Focusing on the difficulty of the heterogeneous spatial database integration, this paper discusses how to introduce the middleware of Open Grid Services Architecture-data Access and Integration(OGSA-DAI) to spatial database application, expands the interface of OGSA-DAI with the function of spatial database access, and implements the integration among the heterogeneous spatial databases effectively. Experiment validates the feasibility of the method.
  • LI Ru-bao; LI Jun; LIAO Hua-ming
    Computer Engineering. 2008, 34(5): 77-78,8. https://doi.org/10.3969/j.issn.1000-3428.2008.05.027
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    eXtensible Business Report Language(XBRL) is a special version of XML for communicating business and financial information. This paper introduces X-SIR, a system for storing and managing XBRL data using a relational DBMS. X-SIR can automatically generate relational schema according to the XBRL data model and automatically transform data in XBRL instance documents into tuples in relational tables.
  • CHEN Li-jiang
    Computer Engineering. 2008, 34(5): 79-81. https://doi.org/10.3969/j.issn.1000-3428.2008.05.028
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    The verb-noun combinations in Chinese often create ambiguities in parsing. This paper proposes a method to label VN combinations automatically by using Adaboost algorithm to combine several Bayesian classifications to identify the VN and VO constructions. It constructs the feature vector depending on verbs, nouns and their context including the number of syllables of words. Experimental results show that this method can achieve reasonably good result. It achieves precision of 90.5% and recall of 88.2% without using any other resources.
  • TAO Li-xin; YANG Jian-sheng
    Computer Engineering. 2008, 34(5): 82-84. https://doi.org/10.3969/j.issn.1000-3428.2008.05.029
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    This paper propose a novel method based on the course of MC(MT) algorithm computation to rebuild an apparent and complete topological structure necessary for mesh simplification to reduce the time and memory of the data structure pretreatment. The method called as six-cube method, rebuilds the appropriate data structure while MC(MT) algorithm extracts the iso-surface.
  • SHAO Yi-chuan; SHEN De-rong; MA Ye; NIE Tie-zheng; KOU Yue; YU Ge
    Computer Engineering. 2008, 34(5): 85-88. https://doi.org/10.3969/j.issn.1000-3428.2008.05.030
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    This paper proposes rotate coordinates fold line strategy as a new multi-dimensional visualization technique, which integrates various methods such as Fisheye and star-graph to stimulate visual thinking. According to features of different visualization technique, Multiperspective Commutative Association(MCA) is proposed to enhance the relations between some visualization approaches to display the multi-dimensional data from various views. Experiments show that the visualization technique not only performs clustering analysis, but also evaluates the precision and reliability of the clusters, and it is user-friendly and displays the results to the user clearly. The visualization method has been applied in EFCS_Grid,
  • DENG Hong; CHEN Li; CHEN Xiao-jun; LIN Yan-ping; WANG Cheng-tao
    Computer Engineering. 2008, 34(5): 89-91. https://doi.org/10.3969/j.issn.1000-3428.2008.05.031
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    The process of the surgery navigation is an operation-sensitive process, and it is important to record and archive the whole process. This paper proposes key technologies for archiving of computerized surgery navigation process based on PACS. At the stage of surgery, the images and track data are acquired by the screen captured tool and the navigation software. These image and data files are converted into DICOM files supported by PACS and transferred into the database in the PACS. The process of surgery navigation is recorded. Subsequently, the original data of process archiving is acquired from PACS, and these data are used to play back and restore the process of surgery navigation. The process archiving is complished.
  • Networks and Communications
  • LUO Juan; TANG Wen-sheng; WANG Wei
    Computer Engineering. 2008, 34(5): 92-94. https://doi.org/10.3969/j.issn.1000-3428.2008.05.032
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    This paper proposes an adaptive scheme to alleviate congestion in sensor networks. It attempts to alleviate the congestion by creating more routing paths. When creating new path is failed, the paper introduces aggregate fairness model to reduce forwarding rate in proportion to upstream link’s aggregate flow weight and to alleviate the congestion. Simulations demonstrate that the scheme can improve energy efficiencies, reduce the number of dropped packets and ensure that some important data packets can reach sink node timely and fairly.
  • ZHOU Ying; WU Zhong-fu; WANG Hao; LI Feng
    Computer Engineering. 2008, 34(5): 95-97. https://doi.org/10.3969/j.issn.1000-3428.2008.05.033
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    In Mobile IPv6 network, the location of Mobile Node(MN) is obtained by the implementation of binding update. During the course, the security disposal of binding update message is the key point of the research. The purpose of CGA algorithm is to prevent stealing and spoofing of existing IPv6 addresses. In this paper, based on the research of CGA, the rationale of CGA is applied in the disposal of binding update message. The problem of care-of-address acquirement and authentication is solved effectually. And the security level of disposing binding update message is improved.
  • TANG Hai-ying; FENG Shuo; YANG Shu-qing; XU Lu
    Computer Engineering. 2008, 34(5): 98-100. https://doi.org/10.3969/j.issn.1000-3428.2008.05.034
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    The availability of SonD system is limited by that of network storage. This paper describes design and implementation of Bluewhale HA-SonD system, which focuses on providing high availability services for client machines and adopts different redundancy mechanisms to each component. The availability evaluation shows that the availability level of HA-SonD system is higher than that of SonD system.
  • LIU Zhen-yu; XIE Sheng-li
    Computer Engineering. 2008, 34(5): 101-103. https://doi.org/10.3969/j.issn.1000-3428.2008.05.035
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    According to the parallel processing of multi-micro engines in IXP28XX network processor, through defining the load deviation and fitness function, a model is built to solve the problems of over-load and congestion in dealing with the packets. Genetic algorithm is used to arrange the workload of every micro-engine in this model. A genetic algorithm with method of multipoint cross and mutation is put forward. The experiments show that this genetic algorithm reduces the iterations and saves the time in searching the optimum value, so the micro-engines quickly reaches the workload balance.
  • LIU Li-ping; CHEN Zhi-gang; ; LIU Ai-xin
    Computer Engineering. 2008, 34(5): 104-106. https://doi.org/10.3969/j.issn.1000-3428.2008.05.036
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    This paper presents an improved algorithm based on particle swarm, which is to resolve dynamic Web Services selection with QoS optimal in Web Services composition. The essence of the algorithm is that the problem of dynamic Web Service selection with QoS optimal is transformed into a multi-objective services composition optimization with QoS constraints. The theory of intelligent optimization of particle swarm optimization algorithm is utilized to produce a set of optimal Pareto services composition process with constraint principle by accelerating global and detail searching speed based on deciding PSO state. Experimental results indicate the feasibility and efficiency of this algorithm.
  • LIU Ying; YU Kan-min; WEI Jun; JI Zheng-zhou
    Computer Engineering. 2008, 34(5): 107-109. https://doi.org/10.3969/j.issn.1000-3428.2008.05.037
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    Proxy Certificates(PCs) is one of key mechanisms in Grid Security Infrastructure(GSI). Users need PCs to access grid services. But there is no effective mechanism to manage the PCs in GSI. An adaptive proxy certificates management scheme based on hierarchical one-way hash chains in grids is presented to solve the problem that PCs’ lifetime does not be controlled neatly and PCs would be attacked easily. A hierarchical one-way chain consists of two or more levels of chains, where values of a first-level chain act as roots of a set of second-level chains and each PC is protected by a hash value, so the PCs’ available time can be controlled adaptively. Results show that the security of PCs management and success rate of tasks are improved. Experiments indicate computation and communication costs much lower in grid environments.
  • XIONG Zhi; GUO Cheng-cheng
    Computer Engineering. 2008, 34(5): 110-112. https://doi.org/10.3969/j.issn.1000-3428.2008.05.038
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    The persistent connection characteristic of HTTP/1.1 may bring extra cost to Web server cluster with content-aware request distribution. To reduce such cost, the Web pages always being accessed by clients in the same session are organized into Web page clusters, and Web page cluster is viewed as a document distribution unit. How to measure the distance among Web pages is a key problem of Web page clustering. This paper proposes a measure of distance among Web pages based on Markov chain, which considers the time correlation of clients’ access and the path of clients’ access. Example shows that, compared with the measure of distance among Web pages based on time correlation, adopting such measure can more effectively reduce the extra cost brought by the persistent connection of HTTP/1.1 after clustering Web pages.
  • LI Wen-hang; GONG Jian-hua
    Computer Engineering. 2008, 34(5): 113-115. https://doi.org/10.3969/j.issn.1000-3428.2008.05.039
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    Mobile Collaborative Virtual Environments MobileCVE) is a new type of collaborative virtual environment running on mobile networks and instruments. In view of some limitations, a framework of MobileCVE is proposed. Limitations can be made up and the merits of mobility and portability can be exploited by computation and storage transfer to the server. Key techniques and the prototype are discussed.
  • RU Xin-yu; LIU Yuan
    Computer Engineering. 2008, 34(5): 116-118. https://doi.org/10.3969/j.issn.1000-3428.2008.05.040
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    The congestion control is a most important protocol, which improves the Internet’s stability and robustness. This paper investigates the current standard slow-start algorithm of TCP congestion control mechanism and its actual problem. A new variant slow-start scheme called “COS-Slow-Start” is presented. Mathematics theory analyses and proves that this new scheme can obviously improve the stability and efficiency of network. NS2 simulation results show that it can significantly reduce both packet losses and traffic burstness, and increase the bandwidth utilization ratio.
  • ZHOU Wei; CHEN Xiao-an; LUO Tian-hong
    Computer Engineering. 2008, 34(5): 119-121. https://doi.org/10.3969/j.issn.1000-3428.2008.05.041
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    The dynamic data exchange is the key technique to realize the Internet supported collaborative design. But the information of each step designing in collaborative design needs to exchange real timely, so many unnecessary data must be contained in dynamic data exchange format. To resolve the problem, the dynamic data exchange technique based on ECA is proposed. The system structure of dynamic data exchange based on ECA is constructed. The ECA rule in dynamic data exchange and the basic relation of events are defined. The dynamic data exchange technique based on ECA is applied to realize the real-time exchange and consistency of the dynamic data between the heterogeneous platforms and CAD systems.
  • ZHANG Miao; KOU Xiao-rui; LUO Jun-yong
    Computer Engineering. 2008, 34(5): 122-124. https://doi.org/10.3969/j.issn.1000-3428.2008.05.042
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    A method of measuring bandwidth of each link in a remote network is proposed. The idea of bandwidth measurement is introduced. The steps of collecting exploring data and getting bandwidth based on those data are listed. Some key problems including how to structure exploring data, how to reduce the number of exploring packets, the parallel schedule mechanism and the steps of regression are discussed. Experimental results are presented, based on which the influence of exploring speed and the queue strategy of packet on the accuracy of the result are analyzed.
  • SUN Yu-geng; WU Xiao-guang; LIU Yang
    Computer Engineering. 2008, 34(5): 125-127. https://doi.org/10.3969/j.issn.1000-3428.2008.05.043
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    This paper introduces a cluster header algorithm focused on concepts and characteristics. For the purpose of data aggregation, centered on real-time data, it designs the routing algorithm based on the event-driven networks. It differentiates every node and chooses the best header and founds the configuration of transmitting tree to guarantee the real-time characteristics. It effectively reduces the transmission of information and the delay of propagation.
  • YU Zhuang-hui; HUANG Yong-zhong; ZHOU Bei
    Computer Engineering. 2008, 34(5): 128-130. https://doi.org/10.3969/j.issn.1000-3428.2008.05.044
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A thought of parallel computing is applied to IM information reversion by putting forward a parallel computing model based on tuplespace. Thinking size and picking it automatically, the model realizes dynamic load balancing. It achieves stability of reversion, through an improved task-taking algorithm. Theoretic analysis and experiments demonstrate that the model can improve the performance effectively.
  • HU Zhi-gang; ZHENG Mei-guang
    Computer Engineering. 2008, 34(5): 131-133. https://doi.org/10.3969/j.issn.1000-3428.2008.05.045
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    Resource mapping is an emergency problem in grid computing area, current research focuses on how to minimize the makespan and improve the throughput, but the research on how to meet the users’ QoS need and improve the mapping performance is not very abundant. For that, a QoS-based resource mapping policy(QSPCR_Sufferage) is proposed. The best resource is chosen according to the task deadline attribute and multiple QoS parameters. The result of experiment indicates that this policy can effectively increase the task request success rate and improve the grid resource utilization.
  • Security Technology
  • YU Jing; LU Yun-ping
    Computer Engineering. 2008, 34(5): 134-135,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.046
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper introduces TDS protocol and communication between SQL Server database systems. Fuzzer for TDS protocol is done. Special packets are designed and three test methods of data mutation, string and field combination are implemented. The validity of the tool is proved by testing two known vulnerabilities of MS SQL Server.
  • PENG Chang-gen; FAN Mei-mei; LI Xiang
    Computer Engineering. 2008, 34(5): 136-138. https://doi.org/10.3969/j.issn.1000-3428.2008.05.047
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Verifiably encrypted signature is usually applied to the fair exchange protocol. However the trusted third party (TTP) is a bottleneck in the fair exchange protocol with a TTP. This paper extends Boneh et al’s verifiably encrypted signature with single adjudicator to a multi-adjudicator scheme. In this scheme, the adjudication can be shared among multiple adjudicators using verifiable secret sharing without trusted center. Based on the proposed verifiably encrypted signature scheme, it designs a contract signing protocol with multiple adjudicators. So the risk that any player colludes TTP can be reduced. In addition, the protocol can provide unforgeability, opacity, fairness and confidentiality. The scheme has lower communication cost due to short signature and aggregate signature.
  • LU Wei-qin; ZHANG Yu; LI Jian-xin; LIU Xu-dong
    Computer Engineering. 2008, 34(5): 139-141,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.048
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The paper proposes a novel decentralized trust evaluation model for grid, called GTruMod. In GTruMod, a formula is proposed to evaluate direct trust by referring to the theory of posteriori probabilities of binary events. Referred to characteristics of the society model about trust relationship, methods are presented to discount feedbacks, compose recommendations, and evaluate the trust value. In decentralize network environments, based on GTruMod, a practical graph–based search algorithm and some optimization methods are proposed to evaluate trust, furthermore its complexity is analyzed. The comprehensive experimental results prove that the model has ability to prevent the malicious recommendation.
  • LIU Zhi-du; JIA Song-hao; ZHAN Shi-hua
    Computer Engineering. 2008, 34(5): 142-144. https://doi.org/10.3969/j.issn.1000-3428.2008.05.049
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at security problems faced in the development of Web services, three methods of encryption, digital signature and authorization are put forward. Analyzing and comparing the security functional mechanism of SSL and XML, fusing the security technologies based on SOAP, it presents a solution scheme on security problems. It adopts XML security protocol to guarantee the security of end to end, proves it is feasible to solve some security problems.
  • CAI Zhao-quan
    Computer Engineering. 2008, 34(5): 145-147. https://doi.org/10.3969/j.issn.1000-3428.2008.05.050
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    By analyzing the loopholes and weakness in the current version of Border Gateway Protocol(BGP) and noting the potential attacks based on TCP, this paper gives the BGP security threat model and the corresponding preventive strategy, and explains how to extend the functions of the protocol. As an example, a typical security precaution setup of the CISCO routing is illustrated. Practice proves that, network security and stability can be effectively improved through access control lists, digital signature, routing filtering, source address detection and protocol extended function.
  • XU Jiao-na; LI Cheng; LI Wei; TANG Fa-gen; LI Yun-chun
    Computer Engineering. 2008, 34(5): 148-149,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.051
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  • LIN Zhao-wen; ZHAO Yi-de; MA Yan
    Computer Engineering. 2008, 34(5): 150-152. https://doi.org/10.3969/j.issn.1000-3428.2008.05.052
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Most of intrusion detection systems nowadays are not really distributed systems which cannot detect the distributed or cooperative attacks effectively. This paper proposes an Agent-based Distributed Cooperative Model(ADCM), which implements cooperative intrusion detection through efficient, normative event messages exchange among Logic Detection Domains(LDDs). It describes the functions of entities, defines the communication mechanisms, and designs some detection Agents which are independent separately, while they can communicate and cooperate with one another to take actions. Results show that ADCM can improve the ability of detecting stealthily and distributed cooperative attacks.
  • ZHAO Zhi-ping; LIN Ya-ping
    Computer Engineering. 2008, 34(5): 153-154,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.053
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    There are no trust nodes in sensor networks as that in traditional networks. Based on cluster structure of sensor networks and threshold secret sharing mechanism, a novel group key management scheme for sensor networks is proposed in this paper, in which only innocent nodes have an efficient group key share. When group is rekeying, multiple entities in a local neighborhood can jointly create a new group key to be distributed by cluster heads securely. Analysis and simulations show that the scheme has lower memory and communication overheads besides good security performance.
  • LAI Xia; HE Ming-xing
    Computer Engineering. 2008, 34(5): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2008.05.054
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Broadcast encryption scheme is wildly used in group communications, such as pay-TV, video-conferencing, wireless and sensor networks etc. In many hierarchical binary tree-based schemes, Group Center (GC) needs spaces to store all related keys. This paper presents a secure session key distribution scheme based on broadcast encryption. The scheme reduces the key storage requirement of GC to a constant size, which is far better than that of the previously proposed schemes and can securely distribute key, join new users and renew encryption-keys successfully.
  • LIU Jia; WEI Bao-dian; DAI Xian-hua
    Computer Engineering. 2008, 34(5): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2008.05.055
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    S-boxes are quite important components of modern symmetric cryptosystems in the sense that S-boxes bring nonlinearity to block ciphers and strengthen their cryptographic security. This paper analyzes the cryptographic properties of the SMS4 S-box. Some algebraic properties of S-boxes such as Balanceness, differential characteristics, linear structures, nonlinearity and Walsh spectrums are investigated. It claims that SMS4 S-box possesses some better properties by being compared with those S-boxes used in AES and Camellia.
  • ZHOU Jiang-tao; ZHAI Jian-hong; ZHANG Hong-li; SONG Xiao-hui
    Computer Engineering. 2008, 34(5): 161-162. https://doi.org/10.3969/j.issn.1000-3428.2008.05.056
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Traditional IPv4-based Intrusion Detection System(IDS) and Network Management System(NMS) need to be upgraded to support IPv6, which needs various IPv6 data, especially the packets with distinct extension headers on IP layer to certify their functionalities. This paper designs and implements an IPv6 packet constructor——IPSender6 based on experiments. Experiments prove that IPSender6 provides test data for IDS and NMS flexibly and effectively.
  • DAI Zi-bin; WEI Xue-tao; CHEN Tao
    Computer Engineering. 2008, 34(5): 163-165. https://doi.org/10.3969/j.issn.1000-3428.2008.05.057
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A finite field polynomial arithmetic unit architecture is proposed in this paper for reconfigurable ECC. The multiplier based on previous digit-serial multiplier architecture uses bit-parallel architecture of local parallel to eliminate reduction modulo circuit effectively, and the multiplier architecture is the same with arbitrary irreducible polynomials. The squaring architecture computes squares by using an LSB, or an LSD multiplier with an adder. Data format of import is controlled through data interface, which achieves requirements of point multiplication for different finite fields.
  • GAO Peng; CAO Xian-bin
    Computer Engineering. 2008, 34(5): 166-168. https://doi.org/10.3969/j.issn.1000-3428.2008.05.058
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    Noise brings great troubles in inspecting chat room because it reduces the monitoring efficiency of chat room. But there are no other clues to distinguish noise and normal utterances directly except time clue, it is difficult to filter noise. With the temporal relations of dialogs, this paper proposes a new method to handle the problem. It deduces the social network by the temporal relations of dialogs, and then judges the noise and filteres in terms of the features of chatters’ relations expressed by social networks. Experimental result shows that the method can judge noise well and improve the accuracy of topic detection.
  • JIN Ran; WEI Qiang; WANG Qing-xian
    Computer Engineering. 2008, 34(5): 169-170,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.059
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    Much of unknown malware comes from transformed known malware. This paper proposes a complete normalization scheme to resolve the common transforming methods, including identical instructions substitution, garbage code insertion and code reordering. It implements a prototype system and a test to the system is conducted using Win32.Evol, a typical metamorphic virus. It makes a useful attempt to adopt normalization to detect metamorphic malware.
  • Artificial Intelligence and Recognition Technology
  • CUI Xin; LI Bo; MA Da-kui
    Computer Engineering. 2008, 34(5): 172-173,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.060
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes Capacitated facility location model for Directly Reusable Network (CDRN) in reverse logistics. Direct and reverse flows are both included and production capacity constraints are appended. Genetic Algorithm(GA) is presented to solve the model for its global search ability. This approach and novel constranit treatment avoids the redundant evaluation of the lower and upper bound in the process of Lagrange heuristic algorithm. The experiment is evaluated by using different parameters. The results indicate that the method does achieve the convergence of the optimal solutions and provides better accuracy steadily and rapidly.
  • JIA Li-yuan; ZHOU Cui-hong
    Computer Engineering. 2008, 34(5): 174-175,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.061
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The convergence speed of Genetic Algorithm(GA) and the quality of problem result are the main inconsistency which affects the performance of GA. This paper proposes the control strategies of improved GA, which are the good subspace operator, the variable crossover probability and variable mutation probability operator and the variable dimension subspace operator. Experimental results show that the convergence speed of this algorithm is so fast to improve GA.
  • YAN Ying; GOU Jin
    Computer Engineering. 2008, 34(5): 176-178. https://doi.org/10.3969/j.issn.1000-3428.2008.05.062
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    An advanced fuzzy recombination operator named SFFRO is proposed based on standardized fitness and applied to Cellular Genetic Algorithm(CGA). The exploitative SFFRO has much more probability to generate offspring closer to the parent with higher fitness, and in the other hand, the explorative SFFRO tends to search in a larger scale for the parent with lower fitness. Therefore, SFFRO indicates the potential search direction and accelerates the convergence to global optimum. In the simulation research, experimental results show that CGA based on SFFRO obviously outperforms others in terms of efficiency and reliability.
  • GAO Li-li; LIU Hong; LI Tong-xi
    Computer Engineering. 2008, 34(5): 179-181. https://doi.org/10.3969/j.issn.1000-3428.2008.05.063
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    A Particle Swarm Optimization(PSO) based on cultural algorithm for solving constrained optimization problems is proposed. This algorithm employs PSO using Gaussian and Cauchy probability distributions in population space, uses situational knowledge and normative knowledge in belief space to guide the evolution of the population. In this way, it exploits the information sufficiently that the optimum individual carries and speeds up the evolutionary process. Experimental results prove the algorithm is superior to basic PSO in quality and efficiency.
  • YE Xue-yi
    Computer Engineering. 2008, 34(5): 182-184,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.064
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Attacks pointing to biometric data are the basic menace of biometrics self-security. For improving the security of iris features data, this paper proposes a bit stream based data hidden approach by embedding iris features data into a face image which is applicable to the dominant method of present iris recognition technologies. While having the high computation efficiency and the zero-decoding-errorrate, the method embedding a key biometric feature into another biometric feature for transmission in a biometrics security net can deceive attackers better, and also is not repressive to the excellent performance of the iris recognition. Experiments show that the data hidden approach can effectively protect iris features data and enhance the iris recognition system self-security.
  • HE Fu-gui; ZHANG Yan-ping; ZHAO Shu; YANG Xue-jie; CHEN Jie; ZHANG Ling;
    Computer Engineering. 2008, 34(5): 185-187. https://doi.org/10.3969/j.issn.1000-3428.2008.05.065
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Researching these time-series which are interdependent as integration, namely multi-variable time-series analysis, the properties of these time-series can be realized better. For the forecasting question of time-series, in this paper, the relative time-series are dealt synthetically. In quotient space model, based on relativity of information, in order to reduce the impact of the incomplete information, the decomposition and synthesis method of quotient space theory is introduced to obtain more accurate information and rules. The result of experiments shows that the method is effective. Therefore, the solution to the problems is undoubtedly a reasonable approach.
  • QIU Xiao-yu; ZHANG Hua-xiang
    Computer Engineering. 2008, 34(5): 188-190. https://doi.org/10.3969/j.issn.1000-3428.2008.05.066
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes kernel nearest neighbor to classify the data sets. The parameter of the kernel function is the most difficulty question of this research topic, so this paper proposes a hybrid approach to use the target function to choose an adaptive parameter. Through testing the approach on a typical classification data sets, and the preliminary results demonstrate that, the target function can provide an adaptive parameter to optimize the kernel function for classification in various domains, especially compared with other kernel-based nearest neighbor classification methods.
  • JIANG Wei; HAO Wen-ning; YANG Xiao-jia
    Computer Engineering. 2008, 34(5): 191-192,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.067
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Data are the base of the simulation training system for commander of combat. But a lack of authority data and the difficulities of data search may lead to the phenomenon that the data can not be controlled. It is a key to strengthen the management of the data and establish a standard. This paper uses the ontology to solve the above problem. The foundation of the ontology has a standard for the definition of the resource data. So it is possible that the data can be shared in the Internet.
  • ZHENG Li-xian; HE Xiao-hai; WU Wei; YANG Xiao-min; CHEN Mo
    Computer Engineering. 2008, 34(5): 193-195. https://doi.org/10.3969/j.issn.1000-3428.2008.05.068
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Learning-based super-resolution technique predicts the high-resolution images from the input low-resolution ones, through learning from a training set which consists of a large number of other high-resolution images. And the results are better than the reconstruction based super-resolution algorithms. The related work, theory and algorithms of learning-based super-resolution are illustrated. The crucial problems which need to be resolved in further work are proposed. Directions of future research are pointed.
  • WANG An-na; WANG Qin-wan; LIU Jun-fang; YUAN Wen-jing
    Computer Engineering. 2008, 34(5): 196-197,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.069
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    Noise is a pivotal factor that reduces recognition rate of a speech recognition system. So how to extract effective speech characteristics becomes an important path for a speech recognition system to increase accuracy. This paper analyses speech feature extraction and makes improvement of it. Experimental results indicate that the algorithm combined with LDA+MLLT+CMS has better robustness than other combinations. Average syllable recognition rate reaches 43.79% by using it under conditions of noises. The algorithm combination has also a good performance in Mandarin Large Vocabulary Continuous Speech Recognition (LVCSR). Syllable recognition accuracy achieves 83.56%.
  • PU Peng-cheng; GUO Xiao-song; GUO Jun-bin; LEI Lei
    Computer Engineering. 2008, 34(5): 198-200. https://doi.org/10.3969/j.issn.1000-3428.2008.05.070
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The traditional LPT(Log-Polar Transformation) method has smooth function to the image, which makes some detailed information loss. This paper proposes an image interpolation based on wavelet transform used for LPT. After making wavelet transform to an image, LPT is done to the four sub-bands. In each sub-band, the optimum image element is obtained according to the characteristic of them. Reconstructed image can be obtained by using inverse wavelet transform for all sub-bands. Experimental results prove that the method is efficient.
  • ZHU Zhen-hua; WU Xiao-juan; WANG Lei; QI Lei
    Computer Engineering. 2008, 34(5): 201-203,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.071
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper uses infrared camera to obtain the image of the driver’s face and locate their eyes with a deformable template in the image. It uses Kalman filter to track the eyes and obtain the parameters of the blink duration which are used to judge the fatigue of the driver, and researches the image processing methods in the algorithm including feature extraction, eyes location and tracking. Experimental results show that blink duration is an effective parameter to judge fatigue.
  • LI Jue; TONG Xue-feng; ZHU Xiu-ming
    Computer Engineering. 2008, 34(5): 204-206. https://doi.org/10.3969/j.issn.1000-3428.2008.05.072
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    This paper propose a novel small eigenvalues resetting Bayesian classifier based on database. This method is an improved Bayes classifier under normal distribution by using a threshold value to substitute the eigenvalues of each class covariance which is smaller than the threshold value. The threshold substitution is selected to minimize the error rate for a given database. The novel scheme performs better than null sub-space classifiers. Experiments on 60 000 digit MNIST handwriting database prove the effectiveness of such method and the recognition ratio is over 96%, and experiments on 3 000 Chinese characters handwriting indicate the recognition ratio over 99%.
  • ZHOU Zhen-gen; GUO Li; YANG Yi
    Computer Engineering. 2008, 34(5): 207-209. https://doi.org/10.3969/j.issn.1000-3428.2008.05.073
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    In current graphics acceleration hardware, MIPmap is a common used filtering technique. But it exists blurring and aliasing artifacts. This paper describes a texture mapping technique, which is based on MIPmaps. With the restricted number of texels loaded from memory for real-time filtering, it improves the algorithms of LOD, and filters the texels with Gaussian filter. As the result, the visual quality is improved.
  • LIU Sheng-peng; FANG Yong
    Computer Engineering. 2008, 34(5): 210-212. https://doi.org/10.3969/j.issn.1000-3428.2008.05.074
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A new image denosing method based on Contourlet transform and Wiener filtering is proposed. By using the statistical information, the Contourlet domain coefficients of the original image are estimated by Bayes shrink threshold algorithm. For further denoising, the final denoising image will be estimated through Wiener filtering. Experimental results show that the denoising effect of this method is better than that of other methods based on Contourlet transform.
  • QIN Chuan; HUANG Su-juan; WANG Shuo-zhong
    Computer Engineering. 2008, 34(5): 213-215. https://doi.org/10.3969/j.issn.1000-3428.2008.05.075
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An image inpainting technique with adaptive filter is proposed. The filter is a nonlinear smoothing operator with a window whose center may deviate from the current missing pixel to be estimated in order to avoid edge blurring. The size and position of the window are adaptively chosen so that the gray-level variance of the interior pixels is below a given threshold and the number of undamaged pixels is sufficiently large. For a tradeoff between image quality and computation efficiency, the algorithm switches between the eccentric window approach for pixels near edges, and the conventional centered window for pixels in a smooth area. Experimental results show that the proposed method provides good results for both types of pixels. In addition, a fragile watermark is embedded into the image to be protected by using a modified checksum method. In this way, subsequently damaged regions can be easily located.
  • LUO Rong-fang; LIN Tu-sheng
    Computer Engineering. 2008, 34(5): 216-218. https://doi.org/10.3969/j.issn.1000-3428.2008.05.076
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Because the finger creases are thought to be stable and different for each individual, this paper proposes a new finger crease recognition method based on projection and wavelet. After image localization and normalization, the subimage for each finger image is obtained. The subimage is a rectangular window on inner side of the finger, which includes the first and the second joint line in the finger image. The subimage is projected onto horizontal axis to construct one-dimensional signal. Wavelet analysis is applied to extract finger crease features from one-dimensional signal to form the feature vector. The proposed method has been tested on a finger database by using the nearest neighbor classifier. The experimental results show the effectiveness of the proposed method in terms of the Equal Error Rate (EER) (≈1.5 percent).
  • CONG Ri-juan; LI Jun-li; HOU Yan-qin; CHEN Bei-jing
    Computer Engineering. 2008, 34(5): 219-221. https://doi.org/10.3969/j.issn.1000-3428.2008.05.077
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Registration methods based on mutual information are popular in medical image processing fields, which are accepted as the most accurate and automated methods. Essentially, registration methods based on mutual information are based on doing statistics of gray values of images. Therefore, if different representations of window widths and window levels of one image are used, registration accuracy will be affected. Based on analysis of window widths and window levels for image quality, and based on the affects of mutual information registration method, series of medical images registration tests are carried out. According to these results and analysis, the recommended window widths and window levels to be used in mutual information registration are given.
  • LU Hu-chuan; ZHANG Ming-xiu; ZHANG Ji-xia; MA Hong-lian
    Computer Engineering. 2008, 34(5): 222-224. https://doi.org/10.3969/j.issn.1000-3428.2008.05.078
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper discusses the detection and tracking of moving human in video sequences gathered from a fixed camera, using a target detection algorithm based on projection information of gray value. An effectual algorithm is proposed to segment multiple people. In tracking process, this paper proposes an algorithm called nearest neighbor matching and implements a whole system for crowd counting. Large numbers of experimental results on several real video sequences from outdoor and indoor scenes have demonstrated the real-time effect(25~30 frames/s and implementing parallelization with four videos), a high precision for sparse crowd and robustness for various environments change.
  • TANG Xiao-heng; XIA Li-min
    Computer Engineering. 2008, 34(5): 225-227. https://doi.org/10.3969/j.issn.1000-3428.2008.05.079
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    This paper proposes a method for intrusion detection based on Boosting fuzzy classification. Fuzzy rules involved in intrusion detection are obtained by genetic algorithm, and Boosting algorithm is employed to change the distribution of training instances during each round of training, so that new fuzzy classification rules extracted by genetic algorithm will put more emphasis upon the instances misclassified or uncovered. Simulation experiments with the data set kddcup’99 show that the method has good recognition performance.
  • Engineer Application Technology and Realization
  • ZHANG Yan-fen; LIU Qiong-sun
    Computer Engineering. 2008, 34(5): 228-230. https://doi.org/10.3969/j.issn.1000-3428.2008.05.080
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A preprocessing method for multivariate data called Orthogonal Signal Correction(OSC) is introduced. This method combines O-PLS algorithm with nonlinear iterative partial least-squares algorithm. This algorithm is used to a fundamental structure of BP network. This paper proposes a novel BP network model based on O-PLS algorithm. The weights initialization and the member of hidden nodes are set by applying the loading weights and factor numbers of O-PLS algorithm. Performances of the BP, PLS, and PLS-BP are analyzed and compared for instance. The result shows that the PLS-BP has better fitting and forecast than BP, PLS.
  • WANG Gong-ming; GUO Xin-yu; ZHAO Chun-jiang; WANG Ji-hua
    Computer Engineering. 2008, 34(5): 231-233,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.081
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    By virtue of object-oriented concept, the efficient octree that stores object’s information in scene is constructed based on number of layers and amount of leaf node link tables. Every leaf node pointed link table that records object’s information is sorted by its size in corresponding special area. The descent order encircle sphere algorithm is used to detect in seeking exactness phase. Then the principal and subordinate Message Passing Interface(MPI) pattern are parallel applied to realize accurate collision detection according to dividing a convex polyhedron to tetrahedrons algorithm. Compared with the traditional octree algorithm, this method does collision detection by using object’s spatial position relation instead of storing lots of spatial object’s triangle faces. It is applied in the soil visual walkthrough based on particle system. The result of this application proves that it has high precision and good real-time performance. It is researchful and can be applied to some extent.
  • BI Zhuo; ZHENG Ying-ping; TANG Chi
    Computer Engineering. 2008, 34(5): 234-236. https://doi.org/10.3969/j.issn.1000-3428.2008.05.082
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    With respect to industrialization of the original embedded microprocessor designed by Tongji University, this paper proposes an engineering method to integrate the microprocessor with the opensource Ethernet controller IP of OPENCORES organization. This method describes how to build the hardware/software interface between the microprocessor and the Ethernet controller IP, testing environment and testing vector. Hardware architecture and critical path analysis are also introduced. The method is proved out by logic simulation and FPGA emulation.
  • SUN Yan-jing; QIAN Jian-sheng; PEI Li-rui; GUO Xing-ge
    Computer Engineering. 2008, 34(5): 237-239. https://doi.org/10.3969/j.issn.1000-3428.2008.05.083
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The network architecture of KJ82 integrated supervision system in coal mine is built upon redundancy ring fiber industrial Ethernet and field bus which has the ability of multi-master transport. It supports networked control and hard real-time priority by which exceptional linkage control of integrated supervision system can be achieved. Traditional network protocols are improved to satisfy real-time data processing and assemble various subsystems. Anti-explosion switch of KJJ23 and safety substation of KJF36 are implemented and used in mining scene. Application and test show response speed, integrating ability, reliability and compatibility of the supervision system are enhanced effectively.
  • BAO Sheng-li; ZHONG Yong
    Computer Engineering. 2008, 34(5): 240-242. https://doi.org/10.3969/j.issn.1000-3428.2008.05.084
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    Combining with the status and requirements for the information construction in the workshops of some cigarette factory, this paper introduces the J2EE architecture and technology to design and implement a real-time monitoring system based on Web pattern. Based on the platform of J2EE architecture, the paper creates a new method to develop large-scale real-time monitoring system using the free Struts framework to fulfil the MVC design mode. In addition, the system structure and functions are described, especially some relative key technologies and database design are discussed detailedly during the system implementation.
  • YAN Feng; GUI Wei-hua; HU Zhi-kun; HE Duo-chang
    Computer Engineering. 2008, 34(5): 243-245. https://doi.org/10.3969/j.issn.1000-3428.2008.05.085
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Considering the problems existed in power electronic applying such as rectifier’s severe working condition, high failure rate and the difficulty of maintenance, a remote monitoring system for rectifier is developed. The system consists of a server and a PLC-based client. The client deals with data acquisition, real-time data processing and sending dictate. The server is a configurable system and supplies the function such as monitoring and alarming, fault diagnosis, and data processing. The programming and realization of communication between server and clients are based on Socket and GPRS. At the same time, a protocol-packet named heartbeat-packets is defined and used in the system so that the status of communication and data transfer can be examined. The practical application results show the effectiveness of the remote monitoring system.
  • XIANG Rong; CHEN Zu-xi; HUO Wei-wei
    Computer Engineering. 2008, 34(5): 246-147,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.086
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the difference of drivers among kinds of LCD, this paper proposes a designing method of driving IP core by LCD based on Nios II. The paper focuses on designing structure and realizing process of IP core for LCD driver based on NIOS II. According to the test, the IP core designed by this method can be applied on different LCDs and runs stably.
  • YAN Ying-jian; XU Jin-song; CHEN Tao; LIU Jun-wei
    Computer Engineering. 2008, 34(5): 248-250. https://doi.org/10.3969/j.issn.1000-3428.2008.05.087
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Instruction Set Simulator(ISS) and its application in processor modeling and verification are introduced. The modeling methods of Instruction Set Architecture(ISA) and Micro-Architecture(MA) are discussed. Furthermore, the implementation of instruction accurate and cycle accurate instruction set simulator are also investigated. Multithreading technology is used in integration of debugger with ISS. Application of ISS in development of a cipher specific processor is presented.
  • SHAO Hua; JIANG Nan
    Computer Engineering. 2008, 34(5): 251-253. https://doi.org/10.3969/j.issn.1000-3428.2008.05.088
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    The paper proposes one adaptive interpolation scheme, which can be used in various geological characteristics. In order to solve problems of functions relative to interpolation coupled too highly and hard to be modified, referring to the idea of design pattern, the scheme divides the function of a traditional interpolation into three modules: subdivision level controlling, net generating and interpolation. The policies in every module are maneuverable and easy to be replaced by another one. Furthermore, the paper proposes an adaptive net generating policy, which brings in the subdivision level controller to solve the problem of difficult control of the scale of subdivision. The effect of this scheme is shown by an example of modeling.
  • LI Ang; WU Wei; QIAN Yi; WANG Qin
    Computer Engineering. 2008, 34(5): 254-256. https://doi.org/10.3969/j.issn.1000-3428.2008.05.089
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    Computation components’ design is difficult in VLSI implementation of neural networks. Differing from traditional methods which use multipliers and adders, the LMN method proposed in this paper uses logic minimization to compress the function’s look-up-table (true table) effectively, and produces the simplest logic expressions. These expressions can be translated straightforward into gates level circuits with canonical structure and little gate delays. It takes non-linear activation functions as example to introduce the method. Results show when using limited bits of fixed point numbers, this method has a better performance in speed and error.
  • Developmental Research
  • SUN Feng; ZHANG Fu-xin
    Computer Engineering. 2008, 34(5): 257-259. https://doi.org/10.3969/j.issn.1000-3428.2008.05.090
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    This paper researches some hardware characteristics of the NAND Flash and the YAFFS Flash memory log file system. On the basis of following the restriction of “write once” on the NAND Flash, it puts forward a new strategy to improve on deleting a paper, and provides an implementation method, focussing on difficulties in realization and relevant solutions. Test on FPGA platform integrated with GODSON-1 IP core indicates that the new strategy can raise the performance of the file system’s basic operations such as rewriting, deleting or resizing a file by nearly 40%, so it has high practical value.
  • FANG Jing; LIU Wen-qing; LI Su-wen
    Computer Engineering. 2008, 34(5): 260-262. https://doi.org/10.3969/j.issn.1000-3428.2008.05.091
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    The characteristic spectral data of trace gas is the basis of monitoring atmosphere pollution through spectrum analysis technology. It is highly relevant in many environmental study fields, such as measurement of trace gases in the atmosphere or air quality estimation. For this reason, a web-accessible database is developed, offering ready access to the main parameters of molecular absorption spectral data. The design of data model, system structure and function composition is described. Web-based and friendly interfaces allow for the input of telnet interactive queries, as well as preview of plots and download of the result spectral data files for thorough, comparative analysis.
  • RUI Ting; ZHOU You; RONG Xiao-li; ZHANG Jin-lin
    Computer Engineering. 2008, 34(5): 263-264,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.092
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    Aiming at “black box” of neural nets, this paper proposes a Particle Swarm Optimization(PSO) algorithm to extract gear-shifting rules from automatic transmissions, analyzes how to encode extracted rules into particle swarms, discusses the process through which the optimal rules are generated by PSO’s velocity-position model, compares the performance between basic and adaptive PSOs in terms of their abilities to search for the optimal solution. Experimental results demonstrate the effectiveness of the algorithm.
  • ZHANG Wei-min;
    Computer Engineering. 2008, 34(5): 265-267,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.093
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    The main functions and the usual architecture of spaceflight control software systems are introduced. A 2-dimensional faults tolerant architecture of spaceflight control software systems is developed. Two dimensions are the version dimension and the critical level dimension. The version dimension A has all of the complete function processes. The version dimension B only has redundant designed processes of some of the most critical processes in version dimension A. Some of them have the same functions as the original processes, others have degraded functions. The version dimension realizes the program faults tolerance between processes. The critical level dimension realizes the data faults tolerance among different critical level processes. If the data from a process flows to lower or the same critical level processes, it can be exchanged immediately. If it flows to higher critical level processes, the data has to be processed by a special faults tolerant process program first. After being processed, the data is transmitted to the destinations.
  • YIN Zhen-yu; ZHAO Hai; WANG Jin-ying; XU Jiu-qiang; LIN Kai
    Computer Engineering. 2008, 34(5): 268-270. https://doi.org/10.3969/j.issn.1000-3428.2008.05.094
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    This paper proposes a kind of embedded processor with Hardware OS(HOS) architecture. In this processor, the task scheduling and management can be achieved by the hardware. An HOS processor with i51-core is designed and downloaded to the FPGA to test. Experimental results show that the efficiency of scheduling is improved by using the HOS processor.
  • CHEN Yong; XU Fang; YUAN Chun; XU Huo-sheng
    Computer Engineering. 2008, 34(5): 271-273,. https://doi.org/10.3969/j.issn.1000-3428.2008.05.095
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    A shared memory based communication platform software under cPCI architecture is proposed. Several key issues, including mutual exclusive access of the shared memory, communication performance assurance, heartbeat mechanism etc., are discussed. The corresponding solutions are described. The stable operation of communication gateway based on this design validates that, it is a platform level communication mechanism, meets the requirement of applications which demand high efficiency, real time capability, good portability and easy to extend.
  • YU Lu-bo; CHEN Chao
    Computer Engineering. 2008, 34(5): 274-276. https://doi.org/10.3969/j.issn.1000-3428.2008.05.096
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    In response to format diversity problem in the webpage information extraction, this paper proposes a new information extraction method based on XPATH clustering. The method utilizes the character of e-commerce website and gives a general mathematic formula. Based on it, this paper uses the thought of webpage statistical information clustering, segments the information block, and realizes the information extraction. This paper proves the validity of the algorithm through the practical website information extraction, achieves good results. Segmentation accuracy is 92.27%, and information extraction accuracy gets 98.24%.
  • WANG Xiao-hua; ZHANG Tian-wen; CHAI Xu-dong
    Computer Engineering. 2008, 34(5): 277-279. https://doi.org/10.3969/j.issn.1000-3428.2008.05.097
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    In order to improve the utility of visualization resource, a gridding method for visualization resource is proposed. The architecture and work mode of visualization resource sharing on grid and the method for encapsulating visualization resource as a grid service are researched. The visualization service is used to capture the screen of visualization application which is saved as an image file with frame buffer, and it is transported to the remote client by Web server. The request from user which is encapsulated as XML file and includes the parameters of visualization task is sent to the visualization service by client. An application example of gridding of virtual environment for virtual prototyping is proposed to illuminate the validity of this method.
  • LI Bin; YIN Chao-wan;
    Computer Engineering. 2008, 34(5): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2008.05.098
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    For solving the problems presently such as collaboration and coordination of calculation entities, rapid and efficient acquisition of information and intelligence platform when e-commerce platform is in heterogeneous and distributed environment, based on multi-agent(including mobile Agent), this paper brings forward an architecture model and implantation method of enterprise business intelligence services broker platform based on JADE. And it presents the business services bidding algorithm and interactive process of service entities based on mobile agent. According to the practical applications, result indicates that the system of service broker platform is feasible and valid.
  • CHAI Xiao-li; XI Jun; NI Ming
    Computer Engineering. 2008, 34(5): 283-封三. https://doi.org/10.3969/j.issn.1000-3428.2008.05.099
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    This paper puts forward an open, modularized embedded computer system architecture based on the analysis of the traditional ones and their demands in advanced application. This system architecture supports the functions of moderate parallel computing, comprehensive processing of data and signal, redundancy structure, and dynamic loading, etc, and it is also able to meet the needs of the high-performance, high-integration and high credibility of embedded computers of the new generation.