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

20 July 2008, Volume 34 Issue 14
    

  • Select all
    |
    Degree Paper
  • HUANG Zhuo; PAN Xiao; GUO Bo
    Computer Engineering. 2008, 34(14): 1-3. https://doi.org/10.3969/j.issn.1000-3428.2008.14.001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To solve the slow convergence problems of Phase-type(PH) distribution data fitting EM algorithm, this paper presents a numerical acceleration EM algorithm. The algorithm achieves the purpose of acceleration by increasing the parameters change of every EM iterative. To illustrate the effectiveness of the acceleration fitting method, the method is compared with the standard EM algorithm by using four benchmark examples. Comparison results show that the acceleration EM algorithm is simple and practical, it can guarantee the convergence of the algorithm, and effectively raise the convergence speed of the fitting algorithm.
  • WANG Tian-qin
    Computer Engineering. 2008, 34(14): 4-6. https://doi.org/10.3969/j.issn.1000-3428.2008.14.002
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper presents a distributed password authenticated key exchange protocol based on (t, n)-threshold secret sharing scheme, in which a set of t servers jointly realizes the identification, whereas any conspiracy of fewer servers gains no information about the verification data. The scheme has the property of forward secrecy. The authenticated users possess the secret session key. Under the DDH assumption, the security of the scheme is proved.
  • LIU Hong; LI Wei; WANG Xiao-ning; LUO Tian;
    Computer Engineering. 2008, 34(14): 7-9. https://doi.org/10.3969/j.issn.1000-3428.2008.14.003
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Grid applications must adapt dynamically to changing run-time environments. This paper studies a dynamic and adaptive resource management model, designs and implements a service-oriented distributed virtual machine called Abacus VM. According to the resource management policy and run-time resource statistics, Abacus VM adaptively allocates resource for grid applications. Experimental results demonstrate that the adaptive resource management model is feasible and efficient.
  • ZHAO Ling; ZHANG Xiao-lin; ZHU Man-jie
    Computer Engineering. 2008, 34(14): 9-11. https://doi.org/10.3969/j.issn.1000-3428.2008.14.004
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper presents a decoding method for regular QC-LDPC codes. In this method, the original check matrix is split into several smaller ones, thus CNU is decomposed into multiple parallel units, which results in great hardware resource reduction. A novel iterative sequence is presented. Compared with the traditional log-BP decode method, the method can reduce the whole logic core size of CNU and VNU by 1/3 under the same bit-rate, and it can improve bit-rate by 1/3 under the same logic core size in the condition of the original check matrix split into two parts.
  • LIU Lei; CAO Cun-gen
    Computer Engineering. 2008, 34(14): 12-13. https://doi.org/10.3969/j.issn.1000-3428.2008.14.005
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Automatic verification of hyponymy relations is a basic problem in knowledge acquisition from text. This paper presents an iterative method of hyponymy verification based on hybrid features. It initially acquires a set of hyponymy features based on semantic, context and space structure of hyponymy. These features are changed into a set of production rules. The candidate hyponymys using Chinese lexico-syntactic patterns from Chinese corpus is verified with multi-features production rules. Experimental results demonstrate good performance of the method.
  • QIAN Bo; TANG Zhen-min; LI Yan-ping; XU Li-min
    Computer Engineering. 2008, 34(14): 14-16. https://doi.org/10.3969/j.issn.1000-3428.2008.14.006
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a new method by modeling the background noise to statistically estimate the pure speaker information. The substantial similarity of noise exists between the voiced and unvoiced regions in the same audio data. Experimental result shows that, the system can adapt the background automatically and acquire better accurate rate, and the robustness can be improved with the method. The speaker recognition accurate rate is higher than 90% in mixture background noise environment.
  • WANG Zeng-ming; YANG Zhao-xuan; SU Yu-ting; FENG Deng-chao; DING Xue-wen; CHEN Yang; WU Jia-peng
    Computer Engineering. 2008, 34(14): 17-19. https://doi.org/10.3969/j.issn.1000-3428.2008.14.007
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An image fusion scheme based on the wavelet transform and an image compression algorithm based on zero-tree coding are proposed, aiming at the demand of the Intelligent Transportation System(ITS). The algorithm is used to fuse visible image and infrared image with wavelet transform and then to compress the fused image by fully employing the importance degree of the subband coefficients and visual characteristic of mankind. So it enhances the integrality and oneness of the traffic information availably and also improves the quality of the system greatly.
  • GUO Yong-zheng; AN Jian-ping; XIA Cai-jie
    Computer Engineering. 2008, 34(14): 20-22. https://doi.org/10.3969/j.issn.1000-3428.2008.14.008
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A new Orthogonal Fre-quency Division Multiplexing(OFDM) signal structure is constructed by using the same PN sequence as guard interval for Time Domain Synchronous Orthogonal Fre-quency Division Multiplexing(TDS-OFDM) system. A low- complexity PN subtraction and signal detection algorithm is proposed based on FFT. The complexity of the algorithm is similar to that of the regular Cyclic Prefix OFDM(CP-OFDM) without complex FIR equalizer. Because some noises in guard interval are introduced to the signal detection, the BER performance of the algorithm degrades compared with that of CP-OFDM. Simulation results show that their BER performance difference is less than 0.1 dB in typical 2-path HF channel, while the performance difference is less than 1 dB in 4-path HF channel whoes time spread is relatively large.
  • YANG Xin-yu; LI Lei; ZHANG Guo-dong
    Computer Engineering. 2008, 34(14): 23-25. https://doi.org/10.3969/j.issn.1000-3428.2008.14.009
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The IPv6 security architecture, IPSec, plays a positive role in the protection of IPv6 networks. To some special attacks, especially DDoS attacks, IPSec appears relatively weak. By analyzing the flow characteristics when IPv6 flooding DoS/DDoS attack occurred, it studies the flooding DoS/DDoS detecting algorithm based on traffic burst used in IPv6. Experiments in Matlab and NS-2 show the detection algorithm can be very good in IPv6 environment for application.
  • WANG Tao; LUO Ming-yang; WU Jun; LIU Bo; ZHANG Jian-hui
    Computer Engineering. 2008, 34(14): 26-28. https://doi.org/10.3969/j.issn.1000-3428.2008.14.010
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Gradient tracking algorithm is widely used in multiple-spacecraft TT&C system and satellite mobile communication system, but the existing hardware implementation method has many drawbacks. This paper analyzes the basic principle of gradient tracking based on uniform circular array and the principle of CORDIC, and puts forward a new FPGA implementation method using CORDIC algorithm and digital beam forming technology. The circuit diagram is designed and the simulation result by using quartus software is also carried out. The simulation proves that the method is correct, more effective and feasible.
  • Software Technology and Database
  • CHEN Da-li; YANG Gen-xing
    Computer Engineering. 2008, 34(14): 29-31. https://doi.org/10.3969/j.issn.1000-3428.2008.14.011
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To choose test case suits reasonably and cover each polymorphic interaction situation, in the test area of object-oriented software, is a research hotspot. Based on the theory of pair-wise, a kind of greedy algorithm is presented to choose test cases, which may sample test cases efficiently. In testing the algorithm to be applied can make test code more efficient and reduce the cost of test. Also, decorator design pattern applied to test framework is also introduced. Such adoption can make test code more efficient.
  • CHEN Zhi-sheng; HUANG Li-ping
    Computer Engineering. 2008, 34(14): 32-34. https://doi.org/10.3969/j.issn.1000-3428.2008.14.012
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To construct the SCM information system that can share the information and has a distributed and integrated data environment, a SCM information system based on WSRF is put forward, in which the stateful resource is modeled by WS-Resource. By this system, the problem of integration of the heterogeneous systems within and outside the company can be resolved. As a result, the information flow between the members of supply chain can be accelerated.
  • WU Yue; WANG Zhi-xue; CHEN Bin
    Computer Engineering. 2008, 34(14): 35-37. https://doi.org/10.3969/j.issn.1000-3428.2008.14.013
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    KAOS approach focuses on analyzing the negative impacts of goals, but it usually ignores positive ones. This paper defines a group of binary relations of goals similar to Tropos to extend semantic framework of KAOS models, which makes the positive and negative effects of goals explicit in the models. It constructs reasoning rules as well as propagation algorithm to detect underling relationships of goals. The introduction of new relationships helps ensuring consistency and feasibility in goal models and establishes a theoretical foundation for requirements feasibility evaluation.

  • KONG De-xiang; LIU Hou-quan
    Computer Engineering. 2008, 34(14): 38-40. https://doi.org/10.3969/j.issn.1000-3428.2008.14.014
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to search ontologies on the Web efficiently and maximize the reusability of ontology, based on WordNet ontology and Jaccard similarity formula, this paper designs an ontology retrieval system to search the ontology dispersed on the Web. It gives the model structure of retrieval system, introduces the modules detailedly and illustrates the method of realizing the system. This paper uses experiments to test usability of the given system.

  • LI Jian-hua; ZENG Hui-qiong; CHEN Song-qiao
    Computer Engineering. 2008, 34(14): 41-43. https://doi.org/10.3969/j.issn.1000-3428.2008.14.015
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    It is an urgent problem that how to insure QoS of composite service effectively when exception happens in participant service. This paper discusses the dynamic calculation of QoS when composite service is running, builds an embedded transaction model of composite service and presents a transaction recovery algorithm of composite service. The algorithm can keep the area of compensation in a lower scope, reduce the cost of compensation, and insure QoS approach to the best when transaction recovering and relaxed atomic of transaction-semantic atomic.
  • HUANG De-cai; CHEN Jian-wu; LIU Duan-yang
    Computer Engineering. 2008, 34(14): 44-46. https://doi.org/10.3969/j.issn.1000-3428.2008.14.016
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper extends an existed non-interactive sampling scheme based on bin-tree to suit the actual situation. It takes the cost of participant truthfully computing a subset of D into account, and also adds the probability that the participant can guess the correct result of f(x), to make the cost of conducting the cheating more expensive than the cost of conducting all the required computations, therefore the cheating brings no benefit. The improved scheme needs fewer samples than the former scheme.
  • FENG Lin; YU Xiao-hang; SUN Tao; SHEN Xiao; PAN Xiao-wen
    Computer Engineering. 2008, 34(14): 47-48. https://doi.org/10.3969/j.issn.1000-3428.2008.14.017
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    According to the problem that existing algorithms are apt to be interfered by noise, a motif mining algorithm based on the Longest Common Subsequence(LCSS) distance is introduced. The algorithm is pruned efficiently by using the heuristic strategy based on the distance between subsequences during the search. Minimum Description Length(MDL) principle is used to calculate the weights of the unequal-length candidate sequences based on the motif patterns selected. Experiment shows the speed of the algorithm prompts at least 60% compared with that of naive algorithm.

  • ZHAO Guo-an; WANG Xiao-jun; LIU Xing-miao; ZHAO Xiu-li
    Computer Engineering. 2008, 34(14): 49-51. https://doi.org/10.3969/j.issn.1000-3428.2008.14.018
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    With the research of management information systems, the design and implementation of general module of management information systems is produced. The general module of management information systems’ idea and method of implementation are used to settle the problem of management information systems’ growing requirement and the commonness of management information systems by constituting the trade’s flow. The general module of enterprise information systems is made up of the control sub-module and 6 sub-modules, and it is implemented on the frame of B/S and C/S and is put in use in fact.
  • ZHANG Xiao-tao; WAN Jian-cheng; HOU Jin-kui; FENG Shi-hong
    Computer Engineering. 2008, 34(14): 52-54. https://doi.org/10.3969/j.issn.1000-3428.2008.14.019
    Abstract ( ) Download PDF ( )   Knowledge map   Save

    Current UI design patterns have some deficiencies in describing complex user interface, which can not display several contends on one finite area or display hierarchical contents. In order to improve the expressive ability of UI design patterns and perfect the abstract expression and visual display of UI, this paper summarizes and extends the current UI design patterns from common pattern, simple-combine pattern and overlapped-combine pattern, and proposes a design pattern for recursive UI. It can be used for designing complex UI, and it also supports the target code generation.
  • SHI Yi-yi; GUO Qiu-hua
    Computer Engineering. 2008, 34(14): 55-57. https://doi.org/10.3969/j.issn.1000-3428.2008.14.020
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Currently the query efficiency of RDF semantic data and recition ratio is not high. By studying the map relation from RDB schema to RDF view, a RDF querying engine can be designed and implemented with the delamination idea for single data source based on the intelligently ontology query. Experimental result shows that the engine can be better implemented to semantic query with high efficiency and has better agility and expansibility.
  • ZHAO Li-qiang; YU Tao; WANG Jian-lin
    Computer Engineering. 2008, 34(14): 58-59. https://doi.org/10.3969/j.issn.1000-3428.2008.14.021
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper presents incremental Swinging Door Trending(SDT) algorithm of historical data based on SQL Server database. For the real-time process data obtained by the OLE for Process Control(OPC), it is compressed by using the incremental SDT algorithm, and the LZW (Lempel-Ziv-Welch) algorithm is adopted for the storage value in the second-level lossless compression. Experimental results show that it can deal with the large process data on line, and at the same time it can reach the utmost compression ratio for the process history data. This storage method can also reduce the storage cost. For the 1 000 data points in one petrochemical factory, the average compression ratio can reach 85% with incremental SDT when the compression tolerance is set to 1%.

  • QIAN Xue-zhong; SHI Pei-bei; ZHANG Ming-yang; WANG Zhong
    Computer Engineering. 2008, 34(14): 60-62. https://doi.org/10.3969/j.issn.1000-3428.2008.14.022
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In traditional k-means algorithm, value k must be confirmed in advance, which restricts a large number of practical applications. Initial centers are selected randomly so that local extremums will be introduced. The common evaluate functions to the optimum number of clustering can not be effectively calculated. To conquer these problems, a new evaluation function-equalization function based on the density of the center initialization algorithms introduced, and the number of generation clustering are automatically calculated. Experimental results prove the efficiency of the improved k-means algorithm.
  • WANG Hua; HU Xue-gang; TIAN Wei-dong
    Computer Engineering. 2008, 34(14): 63-65. https://doi.org/10.3969/j.issn.1000-3428.2008.14.023
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the low mining efficiency problem existing in the mining association rules of FP-growth algorithm on data limited with item counts and transaction length, an improved algorithm(All-subset tree) for mining maximal frequent patterns is proposed, a novel data structure, All-subset tree, which is similar to FP-tree is introduced to store all maximal frequent item sets. The algorithm is in no need of appointed minimum support before scanning the database, and need not rescan the database when assigned minimum support dynamically. Experimental results show that all-subset tree algorithm greatly improves the mining efficiency compared with FP-growth algorithm when mining specific database.
  • CHANG Wei; HU Ke-jin
    Computer Engineering. 2008, 34(14): 66-68. https://doi.org/10.3969/j.issn.1000-3428.2008.14.024
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Enterprise Information System Architecture(ISA) contains descriptions of strategic, business, application, IT infrastructure and inter-relations. ISA’s performance analysis is concerned with layer’s relations and focuses on analyzing performance of IT-related resources. Considering hierarchy of ISA, a service-oriented framework is constructed which facilitates analysis performance of ISA based on theories of petri-net and queuing network. A case study is given.
  • YAO Quan-zhu; WEI Xiao-yong
    Computer Engineering. 2008, 34(14): 69-71. https://doi.org/10.3969/j.issn.1000-3428.2008.14.025
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes an improved algorithm of PRE operation in Symbolic Model Checking(SMC), and it traverses OBDD B(p1r…pnr.B is a step in PRE operation), and “deletes” all the nodes whose variables (p1r, p2r,…,pnr) are quantified, and gets a non-deterministic OBDD NB that equals p1r…pnr.B, which then is translated into an OBDD Bp1r…pnr. The result shows that it can effectively reduce the time and space of PRE operation.
  • HE Hao-yuan; WANG Hong-ya; LIU Xiao-qiang; CONG Jing; LE Jia-jin
    Computer Engineering. 2008, 34(14): 72-74. https://doi.org/10.3969/j.issn.1000-3428.2008.14.026
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Existing research on real-time data broadcast only shows concern over scheduling single data request with deadline constraint. This paper proposes a novel scheduling algorithm called Query-based Scheduling Algorithm(QSA) to address the issue of real-time query processing in on-demand data broadcast environments. The performance of the proposed algorithm is evaluated by extensive simulation, and results show that QSA gains better performance over existing algorithms such as SIN. The maximum 17.45 % reduction in deadline missrate can be achieved by the QSA algorithm over SIN.

  • YU Yang; YANG Yu-lu; YANG Xue-gang; HE Ming
    Computer Engineering. 2008, 34(14): 75-77. https://doi.org/10.3969/j.issn.1000-3428.2008.14.027
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A dynamic scheduling algorithms studied in references are based on centralized grid system or part-distributed grid system, in which there are center node(s) to manage resources. A dynamic scheduling algorithm for the fully distributed grid system without resource management, named DE Scheduling, is proposed. In the algorithm, the redundant scheduling is used to solve the dynamic of environment, and the time of redundant scheduling is set dynamically to reduce void calculations and balance the load of the system. A group of simulations have been done by using the Internet model with 1 000 nodes based on the evolving model for scale-free network with given mean connected degree. When the number of tasks is from 10 000 to 100 000, the time of redundant scheduling always equals 2, the redundant calculations account of the total amount is less than 0.35%, and reduces with the increasing number of tasks.
  • WANG Ai-ping; LV Guo-nian; HUANG Jia-zhu; ZHENG Xin-qi; LIN Bing-xian
    Computer Engineering. 2008, 34(14): 78-80. https://doi.org/10.3969/j.issn.1000-3428.2008.14.028
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper analyzes the relatively unchangeable knowledge and changeable knowledge of the land value assessment business. It designs the main framework based on C/S dynamic architecture for frozen spot, hot spot for document, method and data, and provides the dynamic evolution mechanism. The scheme based on component, C/S dynamic architecture and hot spots dynamic treatment supports dynamic evolution.

  • ZHU Zheng-zhou; WU Zhong-fu; DENG Wei
    Computer Engineering. 2008, 34(14): 81-83. https://doi.org/10.3969/j.issn.1000-3428.2008.14.029
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To improve the recall, precision, and efficiency of grid services discovery, based on ontology technology and rough sets theory, an algorithm OGSDA-RS is designed. Before services matchmaking, according to service request, OGSDA-RS performs the standardization of service request, irrelevant properties reduction and dependent properties reduction. Experiment indicates that the recall and precision of OGSDA-RS tower is above 50%~75% comparing with UDDI and OWL-S. When the number of services advertised is not very large, the efficiency of OGSDA-RS is 2.7 times higher than OWL-S.
  • CHU Wei-jie; TIAN Yong-min; LI Wei-ping
    Computer Engineering. 2008, 34(14): 84-86. https://doi.org/10.3969/j.issn.1000-3428.2008.14.030
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The integration of RFID equipments and enterprises application systems such as ERP is one of the key problems when using RFID technology. RFID middleware is a good solution for this problem, which in practice has accelerated the wide use of RFID technology. A SOA- based RFID application integration solution is proposed, in which enterprises applications can invoke the services provided by RFID middleware across services interface layer. A project for integration between RFID middleware and a warehouse management system is put forward, to verify the solution.
  • YAO Guang-qiang; CHEN Li-ping
    Computer Engineering. 2008, 34(14): 87-89. https://doi.org/10.3969/j.issn.1000-3428.2008.14.031
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Two approaches of integrated programming based on Component Object Model(COM) are introduced. One utilizes the automation server provided by Matlab. The other compiles the Matlab program written in M scripting language to component by using Matlab COM builder, then invoking it in Visual C#. The usual spatial interpolation algorithm in GIS is implemented by these two approaches. The advantages and defects of them are discussed, and the adaptive application range is suggested. The result is that the COM based methods for integration, which make full use of the two platforms, can speed up software development and improve its performance.
  • LIU Ju-bao; CHEN Dong-fang; LI Xin-yu
    Computer Engineering. 2008, 34(14): 90-91. https://doi.org/10.3969/j.issn.1000-3428.2008.14.032
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To deal with the problems such as remote data edit synchronization and multi-replica in distributed collaborative design systems based on P2P model, a distributed mutual exclusion algorithm based on Distributed Hash Table(DHT) and its implementation are given. The problem of remote data edit synchronization is solved by DHT priority queue, and the problem of the multi-replica consistency is solved by "P2P lock" instead of traditional "lock". Experimental results show that the complexity of the algorithm is much lower than others, and the method is effective.

  • Networks and Communications
  • CHENG Lan; CUI Ya-liang; BAO YA-ping
    Computer Engineering. 2008, 34(14): 92-94. https://doi.org/10.3969/j.issn.1000-3428.2008.14.033
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For improving QoS multicast routing in Internet, based on multipopulation PSO and game theory, a new QoS multicast routing algorithm is proposed. It consists of three parts: edge evaluation, game analysis, and multicast tree construction. Based on the degree of membership functions, the candidate edges parameters are evaluated synthetically. Nash equilibrium between network provider utility and user utility are determined on candidate edges by game analysis, and attempts to construct a multicast routing tree with not only user QoS requirements satisfied, but also Pareto optimum under Nash equilibrium on network provider utility and user utility, achieved or approached by the proposed algorithm. The performance of the algorithm is verified by simulation.
  • ZHANG Yong; LUO Wu-sheng; LU Qin
    Computer Engineering. 2008, 34(14): 95-97. https://doi.org/10.3969/j.issn.1000-3428.2008.14.034
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Battlefield communication requires better network performance of real-time and integrity about data transmission. This paper presents an improved AODV route protocol, which is more suitable for battlefield communication among company or small unit. The new protocol decreases data drop ratio and network delay by establishing route ahead, suppressing routing overhead and avoiding congestion. In NS-2 network simulator, experimental results show that it presents better network performance.
  • YANG Zhi-yi; ZHANG Yao-wei; LI Zhi-gang; QIAO Hong-jun; ZHANG Bao-hua
    Computer Engineering. 2008, 34(14): 98-100. https://doi.org/10.3969/j.issn.1000-3428.2008.14.035
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes the design principle of sink node of the Wireless Sensor Network(WSN), analyzes the characteristic and requirement of the sink node, and makes the choice of devices. Based on the low power consuming PXA270 embedded processor, a hardware platform of sink node is implemented with serial port, Ethernet, USB host and CF card interface. The boot process of boot loader is analyzed elaborately, and the porting of Blob in the hardware platform is implemented.
  • LONG Long; RONG Meng-tian; LIU Chao
    Computer Engineering. 2008, 34(14): 101-103. https://doi.org/10.3969/j.issn.1000-3428.2008.14.036
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Now the existent schemes to optimize the performance in wireless LAN is mainly based on centralized algorithms, which aim at family user. This paper proposes a distributed power control algorithm for large scale use. The scheme works based on prediction and sub-traverse, cooperating with a small granularity schedule which is called t-scale timeslot schedule. The simulation on NS2 shows that the scheme reduces the interference among access points and boosts the throughput of the whole network by 3.1 Mb/s(unsaturated) or 1.0 Mb/s(saturated), while the variety of the network can be responded timely.

  • HAO Yong-jie; JIANG Jian-guo;
    Computer Engineering. 2008, 34(14): 104-106. https://doi.org/10.3969/j.issn.1000-3428.2008.14.037
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In the actual communications, low-weight error pattern has higher probability of occurrence than high-weight error pattern. An improved algorithm is proposed in this paper, based on the classical time-domain decoding algorithm of RS code, it takes special treats on the error patterns with 0 or 1 error, and then reduces the computational complexity of them. Compared with the classical algorithm, this algorithm can reduce about half of the computational complexity at most.
  • XU Ye; ZHAO Hai; ZHANG Wen-bo
    Computer Engineering. 2008, 34(14): 107-109. https://doi.org/10.3969/j.issn.1000-3428.2008.14.038
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper analyzes Internet properties gives general definition of Internet space validity and time validity, and defines two property parameters——network density and Internet traveling diameter formally based on quantitative analysis. After proving mathematical relationships between the two parameters, a definition of Internet validity factor is put forward. It gives a combined judge of Internet validity by connecting formula of Internet space validity and time validity. A mathematical model of validity factor based on time-evolvement analysis is given, which makes it possible to forecast and estimate the development of Internet in the future.
  • GU Jian-hua; SHEN Chen ; LI Zhi-gang; PENG Li-jing
    Computer Engineering. 2008, 34(14): 110-112. https://doi.org/10.3969/j.issn.1000-3428.2008.14.039
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Task description is the most basic component of task collaboration in Wireless Sensor Network(WSN), which refers to task description, task decomposition, task allocation, task scheduling and task execution. Recent representative task description fashions are explicitly studied in this paper. A service-oriented task description fashion is put forward towards a three-layer WSN architecture. This description supplies user with a simple, efficient description method and convenience of submitting task requests, decreases the complexity of task assignment system efficiently.
  • LU Gang; LI Hai; ZHANG Wei
    Computer Engineering. 2008, 34(14): 113-115. https://doi.org/10.3969/j.issn.1000-3428.2008.14.040
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    6LoWPAN architecture is a series of technologies and standards on running IPv6 protocol stack over IEEE 802.15.4 LoWPAN. This article analyzes the necessity of the gateway for 6LowPAN and describes the main function of the gateway. Based on the analysis of the IEEE 802.15.4 MAC primitive delivery mechanism, it proposes a dual-MCU-based gateway architecture and provides the design of the gateway in detail, including hardware architecture and protocol architecture, as well as the communication of data and primitives between two MCUs.
  • HUANG Liang; LIU Fu-yan
    Computer Engineering. 2008, 34(14): 116-117. https://doi.org/10.3969/j.issn.1000-3428.2008.14.041
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper analyzes implementation mechanism of technologies, such as TCP/IP, GAMMA, InfiniBand, and SCI, which exist simultaneously in the current high-speed interconnection network. With RapidIO high performance bus technique introduced, this paper researches the prominent feature of the new protocol RapidIO and MPC8458 CPU, and presents a communications technology solution for RapidIO to implement memory mapping.
  • XU Tan; YANG Shou-bao; SUN Wei-feng; ZHANG Peng
    Computer Engineering. 2008, 34(14): 118-120. https://doi.org/10.3969/j.issn.1000-3428.2008.14.042
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Through the experiments conducted on the practical Wireless Mesh Network(WMN) test bed based on IEEE 802.11b/g, this paper comes to the conclusion that the delay of wireless link increases with hops. The performance of WMN does not decrease significantly because of the multi-radio multi-channel architecture used by the WMN test bed. With this architecture, all hops of wireless link can work parallel, which guarantees the end-to-end throughput.

  • LAI Shen-lu; LI Xin; JI Jun-chuan
    Computer Engineering. 2008, 34(14): 121-122. https://doi.org/10.3969/j.issn.1000-3428.2008.14.043
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper uses the uniform user interface as the config interface to realize Single Sign-On(SSO). New interfaces for a new application are generated during the SSO service process, and SSO is implemented as self-extended. Secure tickets sharing pattern guarantees the security of cross domain identification in SSO, and twofold ticket is used to strengthen that. Pluggable implication reinforces the quick start and the adjustment of the SSO.
  • ZHANG Jing; CHENG Nan; MO You-quan; HU Han-ying
    Computer Engineering. 2008, 34(14): 123-125. https://doi.org/10.3969/j.issn.1000-3428.2008.14.044
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on IPv6 and its main OSPFv3 route protocol, this paper analyses the obstacles met possibly by IPv6 unicast QoS route, such as the current IPv4 QoS routing schemes are not appliable, the multiple QoS metrics are difficult to be expressed and their updates cost much to be flooded and so on. It develops the potential for IPv6 of how to use its simplified packet header, flow concept, traffic class and flow label fields to support QoS route.
  • HAN Wei-zhan; ZHANG Zhong-wei; ZHANG Si-dong; SUN Yu
    Computer Engineering. 2008, 34(14): 126-128. https://doi.org/10.3969/j.issn.1000-3428.2008.14.045
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For confirming if an integrated switching technology in a communication network, which is based on a core technology ATM/MPLS and is used to special occasion, can meet the needs of special system performance requirement and service supporting ability, this paper adopts the method of system simulation. The simulation’s modeling is created about this system. The statistics and analysis of the simulation result are designed. After completing the analysis of simulation result, the rationality and validity of the integrated switching technology are validated.
  • TIAN Quan-bin; LI Li-xin; ZHOU Yan-zhou
    Computer Engineering. 2008, 34(14): 129-131. https://doi.org/10.3969/j.issn.1000-3428.2008.14.046
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper studies the virtual Ethernet technology, and develops a VPN system. The system transports packets between kernel space and user space, and simulates a virtual Ethernet environment by constructing virtual NIC in kernel. It realizes the functions of identity authentication based on digital certificate system, traffic encryption, integrality validating and resistance to replay attack by constructing secure tunnel in user space. Test results demonstrate that, besides the primary function of VPN, the system has good performance on passing through net devices and can support multiple net protocols, etc.

  • SUN Su-yun
    Computer Engineering. 2008, 34(14): 132-134. https://doi.org/10.3969/j.issn.1000-3428.2008.14.047
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper brings forward a QoS evaluation model of Web service by adding a QoS authority part on the existing UDDI criterion. It defines a set of QoS categorization tModels, and introduces the concept of QoS quantification. It uses a monitor mechanism initiatively and a feedback mechanism from service consumers for evaluating and adjusting QoS value of Web service dynamically in UDDI. The impartiality, trustworthiness, and real-time characteristics of QoS information are ensured.
  • ZHANG Ying; ZHU Na
    Computer Engineering. 2008, 34(14): 135-137. https://doi.org/10.3969/j.issn.1000-3428.2008.14.048
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A dynamic balanced heuristic algorithm based on game theory and D* principle is proposed to resolve restoration problem in wavelength level for WDM optical networks. On the basis of considerations of the cost of each edge and the use of wavelength comprehensively, through dynamic constructing the evaluation function with using game theory, the algorithm achieves efficient restoration in WDM optical networks. The simulation results show that this algorithm can effectively reduce the blocking rates, promote the restoration rates. In addition, its rapid and intelligent performances can greatly adapt to requirements of restoration time.
  • WANG Qi
    Computer Engineering. 2008, 34(14): 138-139. https://doi.org/10.3969/j.issn.1000-3428.2008.14.049
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the drawback of general single sign-on solution to the Websites that has onerous coding and maintenance costs, this paper introduces reverse proxy to virtual concentration of Websites resources, combines it with Role-Based Access Control(RBAC) and LDAP, and proposes a new single sign-on model. According to the model, less coding is needed to the original websites, thus it has effective performance.
  • Security Technology
  • LU Dian-jie; LIU Hong; ZHANG Gui-lian
    Computer Engineering. 2008, 34(14): 140-142. https://doi.org/10.3969/j.issn.1000-3428.2008.14.050
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A new Trust-oriented RBDM (Trust-RBDM) is constructed. Trust base is introduced on the base of RBAC model while the relationship mapping is established between the users and the trust bases. The delegation is realized by trust chain, so it can resolve the traditional RBDM’s decentralized operation and inferior security effectively. This model is applied to 3D cooperative design based on HOOPS and experimental results indicats that the model can enhance the delegation’s flexibility and security.
  • YANG Wei-bing; SUN Ning-hui
    Computer Engineering. 2008, 34(14): 143-145. https://doi.org/10.3969/j.issn.1000-3428.2008.14.051
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper discusses a secure transport protocol called TIPSec, which is specially designed to be: application transparent, well adapted to NAT networks, highly efficient. TIPSec works in the OS kernel to guarantee the transparency and efficiency, and performs application- payload-only encapsulation, so as to keep the original transport layer information exposed in the encrypted datastream to ease NAT processing. Performance test shows that, equipped with the same ciphers, TIPSec provides about 15% higher bandwidth than IPSec NAT-T.

  • ZOU Cheng-wu; YU Wen-bin; YU Min
    Computer Engineering. 2008, 34(14): 146-148. https://doi.org/10.3969/j.issn.1000-3428.2008.14.052
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on IDS and fuzzy technology, this paper studies intrusion detection system base on fuzzy reasoning information fusion. The model is good at promoting veracity and flexible in IDS. It overtakes some limitation, such as low efficiency, low flexibility, and uneasy to upgrade. This paper studies that fusion center fuses data of all different cluster head of Ad Hoc, and uses fuzzy technology to deduce decision-making. Decision-making of fusion center makes safety evaluation——status of IDS evaluation, situation IDS evaluation, threaten evaluation.
  • ZHANG Xiao-ming; XU Xiao-dong; ZHU Shi-rui
    Computer Engineering. 2008, 34(14): 149-151. https://doi.org/10.3969/j.issn.1000-3428.2008.14.053
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper studies the change of the self-similarity caused by DDoS attack, and proposes a method to detect DDoS attack by calculating the variance of Hurst exponent. An experiment with the dataset of MIT Lincoln Laboratory is conducted to obtain the adjust criterion of DDoS attack. It shows that the proposed method can detect DDoS attack caused by changed variance of Hurst exponent and has higher detection efficiency. Its detection rate is 8% higher than the traditional method of feature matching, while the false alarm rate is 3% lower than the self-similar detecting method.
  • LI Ji-yong; TAO Ran
    Computer Engineering. 2008, 34(14): 152-154. https://doi.org/10.3969/j.issn.1000-3428.2008.14.054
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Kerberos protocol has some security problems, such as password guess, replay attack, and absent authentication. This paper designs a new Single Sign-On(SSO) protocol based on Kerberos. The SSO protocol modifies Kerberos’s framework, which solves Kerberos problem by using one time password and authorization. The new SSO protocol is a more secure and expansibile protocol.
  • YAN Shi-yin; QIAN Hai-feng; LI Zhi-bin
    Computer Engineering. 2008, 34(14): 155-157. https://doi.org/10.3969/j.issn.1000-3428.2008.14.055
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper presents a new image encryption scheme based on composite chaotic system. An external key and two logistic systems are employed for encryption, which shuffle positions and substitute grey values of pixels of image. In the process of grey value substituting, it adopts sub key induced by external key to take samples. Through adding information of shuffle position matrix into the process of grey value substituting, processes of shuffle positions and substitute grey values are mixed in a simple and effective way, which improves coupling property of the encryption system.
  • LIN Lin; TAN Chao-yuan;YAN Yu; LI Bing-fa
    Computer Engineering. 2008, 34(14): 158-160. https://doi.org/10.3969/j.issn.1000-3428.2008.14.056
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a new algorithm of digital watermarking on cellular automata transform. The idea of two-dimensional CA transform is introduced into the algorithm. After the original image is disassembled with cellular automata transform, the watermark which is permuted according to some certain rule will be embedded into the low-level of the carrier picture. Therefore, the robustness of the watermark will be tremendous strengthened as well as its imperceptibility. Experimental results show that the algorithm can resist some usual attacks such as zoom, compression, cropping and noise contamination

  • HAN Ping; ZHU Yan-qin; LUO Xi-zhao
    Computer Engineering. 2008, 34(14): 161-162. https://doi.org/10.3969/j.issn.1000-3428.2008.14.057
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper analyzes the identity authentication scheme using One-Time Password(OTP) for 802.11 wireless LAN, points out a design insufficiency in this scheme, and demonstrates three kinds of attack. In addition, an improved scheme without additional computational complication which can resist the man-in-middle attack, conspiracy attack and Denial-of-Service(DoS) attack is proposed. So the developed scheme is provided to avoid design insufficiency and has higher security compared with the original scheme.
  • LI Shun-qin; LIAO Xiao-feng; ZHOU Qing
    Computer Engineering. 2008, 34(14): 163-165. https://doi.org/10.3969/j.issn.1000-3428.2008.14.058
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A format-compliant selective encryption algorithm for MPEG-4 video data is more practical comparing with its counterpart, but no selective encryption algorithm compliant with JPEG is proposed. Several basic techniques for JPEG-compliant selective encryption algorithm based on Coupled Map Lattice(CML) are proposed and some modifications are given. This paper analyzes the security of the algorithm. Experimental results show that the algorithm for JPEG has high practical value.
  • RUAN Xing-hua; XU Jing-dong; YU Bo-yang
    Computer Engineering. 2008, 34(14): 166-167. https://doi.org/10.3969/j.issn.1000-3428.2008.14.059
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In Vehicular Ad Hoc Networks(VANET), position-based routing is more efficient. But most researches focus on the algorithm performance while the privacy and security issues are neglected. This paper proposes a scheme to protect the privacy and security. In the proposed scheme, position privacy is protected by using pseudonym and routing messages, which are authenticated with group signature algorithm. Security analysis shows that the scheme can effectively defeat the modification, forge and replay attacks while protecting the position privacy of nodes.

  • HUANG Tian-fu; BAI Guang-wei
    Computer Engineering. 2008, 34(14): 168-170. https://doi.org/10.3969/j.issn.1000-3428.2008.14.060
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The Address Resolution Protocol(ARP) is a protocol based on friendly communication and complete trust, so it is prone to be attacked. This paper introduces the working principle of ARP, and analyzes the security vulnerability of the existing ARP and related countermeasures. On this basis, a new method against ARP spoofing is proposed, which is based on improved protocol mechanism. The research shows the improved mechanism can reduce network spoofing attack using ARP effectively.
  • ZHANG Xue-wang; WANG Lin-lin
    Computer Engineering. 2008, 34(14): 171-173. https://doi.org/10.3969/j.issn.1000-3428.2008.14.061
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a design of secure Web E-mail client system based on MIME Object Security Service(MOSS) protocol, which provides digital signature and encryption. Besides the characteristics of normal Web E-mail client, the system has the characteristics such as confidentiality, authentication, integrity and non-repudiation. It originates one technique for integrating management of certification into management of directory inquiries. Selection of cipher suite for the design including AES, RSA and SHA-256 enhances security of the system.
  • ZHAO Zong-qu; LIU Yan-xia
    Computer Engineering. 2008, 34(14): 174-175. https://doi.org/10.3969/j.issn.1000-3428.2008.14.062
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In the distributed computing environments such as wireless network, it is critical to establish a secure session between communicators. A mutual key agreement protocol, namely Symmetrical Authenticated Key Agreement Protocol(SAKAP), is proposed to authenticate identities and establish secure session key between symmetrical users. The security of the protocol is proved in Random Oracle(RO) model, and its performances are analyzed. SAKAP has the advantages of provable security and considerable feasibility over other protocols.
  • Artificial Intelligence and Recognition Technology
  • ZHANG Qiu-yu; YAO Kai-bo; WU Pei-li
    Computer Engineering. 2008, 34(14): 176-178. https://doi.org/10.3969/j.issn.1000-3428.2008.14.063
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to detect and recognize hand gesture from video sequence in real time accurately, a set of rectangle features are used to describe the hand characteristics, and the fast calculation methods of their features and the evaluation ways of the separability of hand gesture class are given. The Adaboost algorithm is improved to deal with the excessive training. Experimental results show that rectangle features can obtain the reliable detector and has a good real-time performance and adaptive capacity in complex backgrounds, but it is more sensitive to the changes of hand gesture. When hand gesture rotates small angle, the detection rates are 95% above.
  • REN Xiao-kang; LI Wen-jing; JIN Yan-feng
    Computer Engineering. 2008, 34(14): 179-181. https://doi.org/10.3969/j.issn.1000-3428.2008.14.064
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a new face recognition approach based on rough set and mPCA. It modularizes the face images according to some very rules; and deals with the modular images by using PCA, reduces the data which has been descented by PCA. This method not only reduces the influence to face recognition brought by the change of pose and expression of the face images, but also wipes off a lot of redundant data. Thereby, it reduces the complexity of computation and enhances the recognition rate observably. Experimental result based on ORL face database shows that the correct recognition ratio can reach 97 percent.
  • HE Jin-hai; LI Wei; QU Lei; LIANG Dong;
    Computer Engineering. 2008, 34(14): 182-184. https://doi.org/10.3969/j.issn.1000-3428.2008.14.065
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The exemplar-based image inpainting algorithm, proposed by Criminisi and his partner, is analysed, in view of some deficiency in calculating the patch priority, an improved method for exemplar-based image inpainting is proposed. The original image is decomposed into structure part and texture part by TV-based decomposition algorithm, the patch priority is calculated by using the structure image, which makes the priority computation more precise. Experimental results demonstrate that the proposed method achieves better results for structure-edge inpainting.
  • CUI Ping-yuan; ZHENG Li-fang; PEI Fu-jun
    Computer Engineering. 2008, 34(14): 185-187. https://doi.org/10.3969/j.issn.1000-3428.2008.14.066
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In nonlinear and non-Gaussian integrated navigation system, the standard particle filter is effective when the observations are not accurate, but it is ineffective and diverges more greatly when the measurements are accurate. In this paper, a self-adjust particle filter is proposed to improve the stability of the filter. The self-adjust particle filter changes the likelihood distribution adaptively according to the statistical characteristic of the observation noises to increase the overlap area between the likelihood and prior distribution. The self-adjust particle filter is applied in non-linear and non-Gaussian integrated navigation system when the observation precision changes drastically from low to high. Simulation results show that the self-adjust particle filter is steady and accurate when the observation precision is high.
  • DING Wei-jie; ZHOU Guo-min; REN Wen-hua
    Computer Engineering. 2008, 34(14): 188-190. https://doi.org/10.3969/j.issn.1000-3428.2008.14.067
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The recognition and classification of plankton images is the important content and precondition to the research of zoology. Traditional methods of plankton images recognition is mainly to be recognized under the microscope by professional. But this method has the demerit of lower efficiency. Under this background, this paper presents a plankton image recognition based on wavelet decomposition and color information entropy. The plankton and eigenvectors are extracted from the images, and K-neighbor classification method is used to recognize the plankton images in database. Experiment proves that the recognition rate is higher than others, and this method is deemed to have high efficiency and stability.
  • ZHU Xia; LI Hong; ZHANG Wei
    Computer Engineering. 2008, 34(14): 191-193. https://doi.org/10.3969/j.issn.1000-3428.2008.14.068
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Using exemplar-based inpainting method to search the source patch globally may lead to error match, and such error accumulates and propagates to other areas quickly, even makes the results completely unacceptable. This paper introduces an algorithm for digital inpainting based on color region segmentation. Patch matching is restricted within the relevant regions where the current patch overlaps. Experimental results show that the method can efficiently handle different cases especially large regions in complex background by producing visually more plausible effect.
  • LIU Bin
    Computer Engineering. 2008, 34(14): 194-196. https://doi.org/10.3969/j.issn.1000-3428.2008.14.069
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The genetic algorithms is introduced to reduce several degrees in one time on NURBS curves. Before using the method, necessary conditions of NURBS curves’ degree reduction with the same end points have been given and proved. The knot series control vertices and weights of NURBS curves are encoded as genes. The selection, crossover and mutation process are executed cyclically to get the global optimum or the sub-optimal by genetic algorithms. The following example proves the NURBS curves can be reduced several degrees precisely and efficiently with this method.
  • YU Wen-jing; WANG Jian-wei; WEI Xiao-peng
    Computer Engineering. 2008, 34(14): 197-199. https://doi.org/10.3969/j.issn.1000-3428.2008.14.070
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Due to the combinatorial characteristics of product configuration, an effective product configuration model is established to transform the complicated problem into the path optimization problem. An improved hybrid intelligent algorithm, which unites the genetic principle, the ant colony mechanism and the simulation anneal theory into the original Particle Swarm Optimization(PSO), is adopted. Based on the discrete characteristic of the product configuration problem, the hybrid intelligent algorithm is transformed from the sequential to the discrete. An example is given to evaluate the effectiveness of the model and the algorithm.
  • XU Xiao-ping; QIAN Fu-cai; WANG Feng; LIU Hong-yan
    Computer Engineering. 2008, 34(14): 200-202. https://doi.org/10.3969/j.issn.1000-3428.2008.14.071
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper presents the system identification method of nonlinear Hammerstein model. The problems of nonlinear system identification are cast as function optimization over parameter space, and the Particle Swarm Optimization(PSO) is adopted to solve the optimization problem. In order to enhance the performance of the PSO identification fatherly, a Velocity Mutation Particle Swarm Optimization(PSOVM) is applied to search the parameter space to find the optimal estimation of the system parameters. Simulation results show the effectiveness of the proposed method.
  • MENG Zhao-xia
    Computer Engineering. 2008, 34(14): 203-205. https://doi.org/10.3969/j.issn.1000-3428.2008.14.072
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    An algorithm is proposed to solve grouping test paper by using optimization of compounding multiobjective. In order to do so, this paper introduces the mechanism of producing and preserving the diversity of antibodies in organismal immune system into evolutionary algorithm. The conceptions of multiobjective selection entropy and selection probability based on concentration adjustment are defined, and strategies of antibody clonal selection and high are introduced. This algorithm fully realizes conception of optimal pareto, and is characterized by parallel search and dynamic adjustment of length of individual coding, optimal pareto individual storing outside mass(immune memory) and constant modification.

  • XIU Chun-bo; ZHANG Yu-hong
    Computer Engineering. 2008, 34(14): 206-207. https://doi.org/10.3969/j.issn.1000-3428.2008.14.073
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper proposes a hybrid optimization algorithm to resolve combinatorial optimization problem. Aswarm degree in the artificial fish school algorithm is used in ant colony algorithm. During the initial process of the optimization, the aswarm degree plays the main role to guide the ants to search the new path randomly, which makes the algorithm have the stronger ergodicity searching ability. The role of the aswarm degree gradually decreases to zero, the algorithm becomes the conventional ant colony and completes the optimal process by the principle of pheromone positive feedback, which insures the algorithm to have a quick convergence rate. Simulation results prove the validity of the algorithm.
  • DENG Wei; SU Mei-juan; DONG En-qing
    Computer Engineering. 2008, 34(14): 208-209. https://doi.org/10.3969/j.issn.1000-3428.2008.14.074
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper presents a new type of neural network for pattern classification namely Dynamic Supervised Forward Propagation Network(DSFPN). Although the network is based on the improved forward-only version of the Counterpropagation Network(CPN), its hidden layer is trained in a supervised manner by using a modified second version of Learning Vector Quantization(LVQ2) algorithm, and an incremental training strategy is adopted. New hidden neurons are created based on a measure of suitability during the training with dynamic growth of the hidden layer. Experimental results of Cone-Torus planar point classification and speaker-independent isolated digital word speech recognition show that DSFPN requires two order of magnitude less training time than the Multilayer Perceptron(MLP), and has higher training speed than the improved CPN, while the best testing accuracies achieve 92.25% and 98.7%, better than the two networks.
  • WEN Xue-zhi; YUAN Huai; ZHAO Hong
    Computer Engineering. 2008, 34(14): 210-212. https://doi.org/10.3969/j.issn.1000-3428.2008.14.075
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A vehicle detection algorithm based on low contrast images is presented. The Region of Interest(ROI) is obtained by using the segmentation algorithm in the image. It performes preprocessing, extracts the edges and texture features of the ROI with the algorithm of Haar wavelet feature extraction, and uses Support Vector Machine(SVM) to detect vehicle. Experimental results demonstrate the superiority of the proposed approach, whose detection rate is 90.6% and false alarm rate is 3.8%. The performance of the algorithm can be improved by cumulate learning.

  • Multimedia Technology and Application
  • WANG Hui-ya; XU Hua-hu; WU Pei; XIE Yi-qun
    Computer Engineering. 2008, 34(14): 213-215. https://doi.org/10.3969/j.issn.1000-3428.2008.14.076
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    With the help of integrated multi-technology, the host communicate is made with the spectators in the actual scene. The spectator who is participating in the interaction is making a program with the host on the screen. This article introduces the technology of real-time composition and the technology of automatic interchange in multiple video frequency on the spot, and presents the principles and methods by the example of “real-time virtual knowledge questions and answers with the host”.
  • WANG Yong-yu; YUAN Chao-wei; SUN Qu
    Computer Engineering. 2008, 34(14): 216-218. https://doi.org/10.3969/j.issn.1000-3428.2008.14.077
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A new method for scalable video coding, using three-band lifting-based motion adaptive transform, is presented in this paper. A three-band motion-compensated lifting steps are used to implement the temporal wavelet transform. It extends the classical Motion-Compensated Temporal Filtering(MCTF) and offers higher temporal scalability flexibility, and it provides improved compression performance by using specific motion model according to real video sequences. The experimental results demonstrate the effectiveness of the framework.
  • JI Bang-guo; WANG Cui-rong; LI Yan; ZHAO Yu-hui
    Computer Engineering. 2008, 34(14): 219-221. https://doi.org/10.3969/j.issn.1000-3428.2008.14.078
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Facing to the feature of delay and jitter in the course of transporting media data in present IP network, this paper designs and realizes the controllable-quality system used for streaming-media server based on fuzzy-control theory in virtue of characteristic of the RTP. It can automatically change the strategy of sending according to the condition of network. The method which is to discard some unnecessary frame based on the feature of coded data not only can save certain brand width, but also guarantees the transportation of key data. Consequently, that assures favorable quality of service.
  • XU Zhi-liang; WANG Jian-hua; XIE Sheng-li
    Computer Engineering. 2008, 34(14): 222-224. https://doi.org/10.3969/j.issn.1000-3428.2008.14.079
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Error concealment is an attractive approach to combat channel errors for video transmission. Aiming at recovering the damaged macroblocks which belong to inter-coded model, an effective error concealment algorithm for motion vector recovery based on MRF-MAP is proposed in this paper. The motion vectors field is modeled as Gauss-Markov Random Field(GMRF). The motion vectors of the damaged image macroblocks can be recovered adaptively by Maximum A Posteriori(MAP), and the weight is selected adaptively based on the spatial information and temporal information. Simulation results show that the proposed method offers significant improvement on both objective PSNR measurement and subjective visual quality of restored video sequence.
  • Engineer Application Technology and Realization
  • GUO Xue-feng; SUN Kai-jun; ZHANG Bin; HU Ming-chang;
    Computer Engineering. 2008, 34(14): 225-227. https://doi.org/10.3969/j.issn.1000-3428.2008.14.080
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to use the best resources and the lowest bandwidth to achieve Godson system available display controller, this paper focuses on the integrated display controller of northbrigde for Godson-2E and the design and realization of display controller, and discusses the test data analysis and the performance optimization work. Test results indicate that a simple display controller of the Godson-2E system fully meets the requirements of low-end application.
  • LIU Ying; LUO Jia-rong ; LI Gui-ming ; LI Shi
    Computer Engineering. 2008, 34(14): 228-230. https://doi.org/10.3969/j.issn.1000-3428.2008.14.081
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For managing and controlling dozens of data acquisition subsystems on EAST, it is necessary to make data acquisition control system between master control system and the data acquisition subsystems. Data acquisition control system provides information services, process control and status monitor, etc., and its design is based on C/S and B/S combination mode. An application of this system has been demonstrated on EAST Tokamak in 2006.
  • TIAN Jia-yin; HE Yan; SHI Ru-jie; MIN Hao
    Computer Engineering. 2008, 34(14): 231-233. https://doi.org/10.3969/j.issn.1000-3428.2008.14.082
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A novel baseband-processor for Low Frequency(LF) Radio Frequency Identification(RFID) tag is presented. A new asynchronous method for data demodulation is proposed to solve the clock halting problem in 100% Amplitude Shift Key(ASK) modulation mode. A new command decoder is designed to increase command decoding speed. Several low-power techniques, such as power management, architecture optimization, etc., are also implemented to enhance tag responding speed and interference immunity and to reduce chip area as well as power consumption. The test results prove the completeness of its expected functionality and its low power consumption. The chip is fabricated in 0.18 μm 2P4M CMOS standard process.
  • XIAO Hao; LI Jin-tao; LUO Hai-yong; ZHU Zhen-min; ZHAO De-hai; LI Ting-ting
    Computer Engineering. 2008, 34(14): 234-236. https://doi.org/10.3969/j.issn.1000-3428.2008.14.083
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper introduces an Electronic Measurement Workstation(EMW) design and implementation based on Virtual Instrument(VI) architecture. It introduces the idea of the Event Processor(EP) and implements it through FPGA. The EMW uses the EP as the control unit of the system, and USB2.0 bus as the communication means between the device and the PC. It integrates several hardware modules, such as oscillograph, logic analyzer, signal generator, etc. The software is developed by using LabWindows/CVI and VC++7.1 based on Windows OS, and it realizes the synchronization and inter-action between related measurement modules.
  • LIU Yu-jing; HUANG Wei; WANG Yu-yan
    Computer Engineering. 2008, 34(14): 237-239. https://doi.org/10.3969/j.issn.1000-3428.2008.14.084
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The technology of Asynchronous Transfer Mode(ATM) is used in Wide Area Network(WAN) and Local Area Network(LAN) as a basic technology for the application of broad band. In this paper, with the application of ATM technology, an ATM switch chip set is referred to as an object under research. Aiming at the FPGA prototype of an ATM switch control circuit which is one of the chip set, a method of automated verification based on Tcl is advanced and functional verification of the ATM switch control circuit is accomplished. The application test shows that the voice service and the IP service are all working in order in communication and the test result of relay signaling is correct.
  • TANG Jian; ZOU Rong
    Computer Engineering. 2008, 34(14): 240-242. https://doi.org/10.3969/j.issn.1000-3428.2008.14.085
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper discusses an Agent oriented spatial data loading model for vehicle monitor. The model divides tasks of huge static map loading and real time vehicle spatial data loading to atomic task, then displays the data. It takes full use of the Agent’s feature: autonomy, pro-activity and reactivity to process map data and vehicle data. As a result, the problem of slowing down the system response caused by displaying vehicle information in real time and huge map data can be resolved. And this model is a good usable example about how to apply the thought and method of Agent to develop GIS.
  • JIN Xiang-ping;
    Computer Engineering. 2008, 34(14): 243-245. https://doi.org/10.3969/j.issn.1000-3428.2008.14.086
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In accordance with the national standards of pre-stressed strand stretching experimentation and the deficiency of its tracking- identification-command system at the present, this paper comes up with a tracking-identification-command system of pre-stressed strand stretching experimentation based on a JL-2008 USB data collecting instrument, elaborates on the fulfillment of its hardware and software and the design of its relevant programs, then summarizes that the tracking-identification-command system bore several advantages such as low cost and power consumption, high reliability and general purposes, high test accuracy and convenient measurement.
  • LIU Ze-wen; TANG Liu-chun
    Computer Engineering. 2008, 34(14): 246-247. https://doi.org/10.3969/j.issn.1000-3428.2008.14.087
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Most of the LAN security measures concern how to prevent attacks of outer network, while less attention is paid to the security of inner local network. To enhance the security of inner local network’s data transmission, security network adapter based on SOPC technology is designed and also implemented. In the design, the DES algorithm and LAN protocol self-define which are the key technology to enhance the security of data transmission are used. The test result shows that the adapter is convenient, effective and easy to reuse, and it also works well in real LAN environment.
  • LI Shou-xuan; ZHANG Hua; LIU Ji-zhong; YANG Wu-qiang; ZHU Ke-hua
    Computer Engineering. 2008, 34(14): 248-250. https://doi.org/10.3969/j.issn.1000-3428.2008.14.088
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A speech control system for ordinary wheelchair movement is realized with speech recognition technology, and the hardware and software design of the system are introduced. Through speech recognition and the drive module of intelligent wheelchair, the movement including marching, countermarching, turning left, turning right, stop, speedup and slowdown is realized, and the speed of wheelchair movement can be adjusted by speech according to movement request. The frame of the speech control system based on SPCE061A is simple, the ratio of capability to price is high, the system can be enlarged in function and transplanted easily and has wider application foreground.
  • LI Jian-sheng; LAN Chao-zhen; XU Qing; WANG Peng; JIANG Ting
    Computer Engineering. 2008, 34(14): 251-252. https://doi.org/10.3969/j.issn.1000-3428.2008.14.089
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper expatiates the necessity of building distributed near-earth space environment simulation platform from its essentiality to the human survival. In order to have better expansibility, repetition and cooperation, this paper advances the near-earth space environment simulation platform federation based on High Level Architecture(HLA). It designs the main federate to most objects of the space environment. It implements the distributed integration of each federate in the federation, and is applied to the real-time simulation of aerospace and space environment.
  • WU Jin-hua; ZHENG Geng; LI Ju-guang
    Computer Engineering. 2008, 34(14): 253-255. https://doi.org/10.3969/j.issn.1000-3428.2008.14.090
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on AT91RM9200 microprocessor, the paper introduces the implementation process of one embedded wireless data terminal. This design can bring two advantages: the simplified hardware frame and the complete network protocols achieved by running ARM-Linux operating system on it. The two typical applications based on the device are presented and the key points of the design are analyzed in the paper.
  • Developmental Research
  • XIANG Rong; CHEN Zu-xi; MO Lan
    Computer Engineering. 2008, 34(14): 258-260. https://doi.org/10.3969/j.issn.1000-3428.2008.14.092
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Single directory services of existing grid monitoring system has low querying efficiency caused by huge date storage, while much nesting will affect querying performance, sothis paper proposes a layered directory services system structure which is carving up on fields. According to experiment, it shows that the system structure satisfies the performance characteristic of grid environments completely, and it precedes traditional monitoring system of single directory services in large-scale application. Organizing messages of grid nodes on field fits manage mode of actual command department or institution, so it has strong expansibility.
  • LIU Feng; YANG Zhi-gao
    Computer Engineering. 2008, 34(14): 261-262. https://doi.org/10.3969/j.issn.1000-3428.2008.14.093
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper analyzes the characteristic of the MapObjects secondary development, and designs a geography information system suit forest pest management. It analyzes the architecture, principle and function of the system, and bringes forward a method to collect, process, and correlate the spatial and attribute data. It focuses on introduction of software. The implementation of the system changes the traditional way of forest pest management and improves the efficiency of the management.
  • HUANG Mei-fa; JING Hui; ZHONG Yan-ru; LIU Fu-yun
    Computer Engineering. 2008, 34(14): 263-265. https://doi.org/10.3969/j.issn.1000-3428.2008.14.094
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Shape distribution algorithm of 3D model retrieve uses pseudo random numbers to sample points on the model surface, which makes the retrieve precision low and the result unstable. This paper proposes a method which employs quasi random sequence to sample points on the model surface. More uniformly distributed random sequences in zone [0, 1] are generated based on Halton sequence, and transformed into the proper sequences in the sampling space. The 3D model retrieve experimental results show that the retrieve efficiency is improved by using this method.

  • NI Yong-jun; WEI Zhe
    Computer Engineering. 2008, 34(14): 266-268. https://doi.org/10.3969/j.issn.1000-3428.2008.14.095
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Using optimistic replication method, this paper proposes a new method of government information data consistency based on structure array. Distributed data storage mechanism is established. The record mode of government information data and structure array is defined. The method can support government information data which are in the distributed e-government system update and data consistency control more efficiently with lower communication and storage cost in mobile business environment.
  • SONG Xu-dong; WANG Yi; LIU Xiao-bing; ZHANG Tong-xue
    Computer Engineering. 2008, 34(14): 269-271. https://doi.org/10.3969/j.issn.1000-3428.2008.14.096
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Synthetic Decision Support System(SDSS) contains multitudinous key technologies. To solve the difficult problem during the design of the SDSS, this paper proposes the designing idea based on component technology of the SDSS, presents its architecture based on business component and service component, as well as the component model of the system. It develops a feasible method for the construction of the SDSS, reducing software complexity and enhancing software reuse.

  • CHEN Jun-yong; LI Xiang-yang; GAO Hong-jun
    Computer Engineering. 2008, 34(14): 272-273. https://doi.org/10.3969/j.issn.1000-3428.2008.14.097
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Begin from the status of mass spectrometry measurement and control system software in the nation, this paper analyzes the shortcomings of them, develops the GPIB bus driver program of mass spectrometry system for Windows platform based on WinDriver according to the idea of object-oriented, and designs the user interface with forms of Dynamic-Link Library(DLL) and class, that solves some actual problems existing in use of the software such as the bad transplantable capability and update problem, and it provides a good example for the driver program development of the software for mass spectrometry and other intelligent measurement and control systems.

  • LI Rui; LING Yun-xiang; LAO Song-yang
    Computer Engineering. 2008, 34(14): 274-276. https://doi.org/10.3969/j.issn.1000-3428.2008.14.098
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The natural human computer interaction technology is progressing rapidly. There is a large gap between two-handed interaction technology and application space, which results in the difficulty in expansive application of two-handed interaction. This paper describes command space from the view of cognition, developes a command space interaction response model based on two-handed interaction according to the application background of command space, distributed cognition and user-centered principle. It analytically describes the relationship between user’s background knowledge and interaction response as a basis of two-handed interaction design in command space.
  • TANG Chuan; LI Jun; ZHOU Jun
    Computer Engineering. 2008, 34(14): 277-279. https://doi.org/10.3969/j.issn.1000-3428.2008.14.099
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    By analyzing the existed data layout algorithm of heterogeneous disk array, this paper proposes a new method called Dynamic Stripe Unit(DSU) raid level 5. This method assigns the stripe unit size according to the performance parameter of each disk, and resolves the problem of counting and placing parity unit by mirroring the heterogeneous disk array to virtual homogenous disk array. Through combining the dynamic stripe unit and left-symmetric parity distribution, the algorithm makes the load balanced or near balanced. Simulation results show that the algorithm has higher performance than raid5 at most 40%, and is adapt to multiple applications.

  • XIE Heng; ZHANG Jie-kui
    Computer Engineering. 2008, 34(14): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2008.14.100
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Low-integration within the informationization among travel agencies is the main problem which currently restricts the development of native tour e-commerce. A new business model called tour-mart is introduced. This model focuses on cooperation of supply-chains to rebuild travel business. An information platform based on tour-mart and Web Services is discussed. The practice in eight travel agencies shows the platform may enhance the integration of resources and the efficiency of cooperation.
  • ZHANG Yan-yuan; JIAO Lei
    Computer Engineering. 2008, 34(14): 283-285. https://doi.org/10.3969/j.issn.1000-3428.2008.14.101
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the embedded file system CFFS oriented towards high capacity NAND flash chips, and according to the approach that it indexes its data on the chip, this paper proposes a data recovery mechanism by introducing new data structures, such as indexing node and page bit map, and their corresponding algorithms to CFFS. In this mechanism, the flash file system can recover to a consistent historical state when its data is damaged so that the consistency and availability of the data are effectively guaranteed.