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Key Stream Generator Based on Combination of FCSR and LFSR
ZHENG Yu; HE Dake; TANG Xiaohu; DENG Zijian
Computer Engineering    2007, 33 (05): 32-35.   DOI: 10.3969/j.issn.1000-3428.2007.05.011
Abstract12845)      PDF (192KB)(1207)      
A novel stream cipher based on the combination of FCSR and LFSR is proposed by Schneier, which is paid close attention by researchers. In this paper, the properties of this stream cipher are analyzed and the theoretical upper bound of period and that of linear complexity are presented. Then, how to select the parameters of FCSR and LFSR is discussed so that the output sequences can access the theory up bound as much as possible. Meanwhile, the pseudorandom properties of generated sequence are checked by eight tests in NIST STS package. According to the testing results, the generated sequences have good pseudorandom properties if the parameters are selected as the proposed rule. The stream cipher is realized in FPGA and compared with the implementation result of other stream ciphers, which proves this stream cipher is very efficient and can be employed in mobile equipment.
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Cited: Baidu(2)
APTZ Adjustment Based on LFPL Under Constant Illumination Condition
SU Ji, YI Gui-Sheng, WEI Zhen-Hua, LIU E-Hui
Computer Engineering    2011, 37 (3): 4-6.   DOI: 10.3969/j.issn.1000-3428.2011.03.002
Abstract12427)      PDF (130KB)(1022)      
To improve the initivative and stability of Pan-Tilt-Zoom(PTZ) adjustment in visual system under constant illumination condition, Active Pan-Tilt-Zoom(APTZ) adjustment method based on Local particle Filtering Pre-Location(LFPL) under constant illumination condition is proposed. Target pre-location mehtod based on local particle filter is used to realize automatic estimation calibratiing for moving target. Initivative of PTZ adjusting is improved and nonlinear tracking problem can be settled. Dynamic selecting illumination-inviarants as filtering particles can overcome the affect of illumination varying and noise in target pre-location algorithm and robust of visual system is improved. Fuzzy control method is used to control pan and tilt to improve the stability of visual tracking system. The correctness and accuracy are tested by experiments. Long distance tracking for varying speed moving target using this method shows it is more stabile than the traditional method. Moving target racking under varying illumination and noise conditions shows ideal result.
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Semantic-based Keyword Extraction Algorithm for Chinese Text
WANG Li-Xia, HUAI Xiao-Yong
Computer Engineering    2012, 38 (01): 1-4.   DOI: 10.3969/j.issn.1000-3428.2012.01.001
Abstract10348)      PDF (307KB)(9135)      

In order to overcome the limitation of literal matching and lacking semantic concept of the traditional keyword extraction algorithm, this paper presents a Semantic-based Keyword Extraction(SKE) algorithm for Chinese text. It uses semantic feature in the keyword extraction process and constructs word semantic similarity network and uses betweenness centrality density. Experimental results show that compared with the statistic based keyword extraction algorithm, the keywords SKE algorithm extracted are more reasonable and can represent more information of the document’s topic, and the SKE algorithm has a better performance.

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Cited: Baidu(24) CSCD(8)
Improved NAMK Color Images Representation Algorithm
ZHENG Yun-Beng
Computer Engineering    2011, 37 (2): 203-204.   DOI: 10.3969/j.issn.1000-3428.2011.02.070
Abstract10085)      PDF (147KB)(965)      

By taking advantages of the characteristic of Gray code that can extend or remain the block character of binary images, this paper proposes an improved Non-symmetry and Anti-packing Model with K-lines(NAMK) representation algorithm for color images, which is called NAMKG algorithm. The description of NAMKG algorithm is presented and the storage structure and the total data amount of the algorithm are analyzed. Theoretical and experimental results show that, compared with NAMK and Linear Quadtree(LQT), NAMKG can effectively reduce the number of subpatterns and reduce the storage room.

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UVSP:Model of Management Mechanism for Grid and P2P Resource Fusion
YE Jun; LI Zhishu; YIN Feng; NI Jianchen; LI Qing
Computer Engineering    2007, 33 (09): 117-119,.  
Abstract9827)      PDF (165KB)(943)      
The characteristic of Grid and P2P systems is analyzed, and a four-layer model called UVSP for grid and P2P resource fusion is presented that has a good character in the resource representation, discovery, access and cooperation. In UVSP model, a Bootstrap based on DHT is added into grid and a peer service is implemented in every P2P node. The resource management architecture is discussed against UVSP. A prototype experiment is realized with BT tracker functionality. The UVSP model is helpful to integrate resources in grid and P2P systems, also available to heterogeneous P2P systems as a reference for resource share and cooperation.
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Architecture of High Speed Network Content Auditing System
Based on MPMF Algorithm
YE Jinxing; ZHAI Weibin; LIU Baoxu; JIANG Zhuoming; XU Rongsheng
Computer Engineering    2007, 33 (14): 104-106.   DOI: 10.3969/j.issn.1000-3428.2007.14.036
Abstract9807)      PDF (189KB)(1099)      
The main part of high speed network content auditing system(HSNCAS) is introduced. The process model of HSNCAS is classified into pipelining model and multi-section model. An algorithm of multi-priority memory feedback (MPMF) for pipelining model is presented and system software architecture is designed based on it. The MPMF algorithm forecasts and sends feedback of different priorities to the load balancer by the memory usage of every part of the system. It can effectively use the hardware resources and improve the overall data processing rate. A solution for “half session” is also proposed.
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A New Method for Approximation of Class Unions Based on Dominance-matrix Within DRSA
LI Ming; ZHANG Baowei; ZHAO Li
Computer Engineering    2006, 32 (16): 100-102,.   DOI: 10.3969/j.issn.1000-3428.2006.16.037
Abstract9771)      PDF (137KB)(839)      
Dominance-based rough set approach (DRSA) is an extension of classical rough set theory (RST). Approximation of class unions is a very important approach in DRSA. Aiming at the disadvantage of the classical method, this paper presents a new methodology for approximation of class unions based on dominance-matrix. It only needs to calculate the dominance-matrix and does not need to consider the preference relations one by one. Thus it greatly simplifies the process and decreases the computing complex by k times(where k is the number of the decision classes). Besides it is intuitive and efficient. The example illustrates its feasibility and efficiency.
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MRGP-based Measurement for Availability of Pervasive Computation System
WANG Haipeng; ZHOU Xingshe; ZHANG Tao; XIANG Dong
Computer Engineering    2007, 33 (04): 37-39.   DOI: 10.3969/j.issn.1000-3428.2007.04.013
Abstract9547)      PDF (209KB)(1078)      
With the vision of anytime anywhere computation, the availability measurement is playing an important role in pervasive computation. In the perspective of quantitative analysis, this paper presents an MRGP-based approach to address the user associated availability measurement of pervasive computation system. A bidirectional extended user model is developed for describing user behaviors. An MRGP model is established, and a stochastic process-based analysis is conducted. The transient and steady availability are provided for this model, and a novel availability metric, called request availability, is suggested. Numerical analysis is carried out and the results argue that the approach and availability metric can give reasonable evaluation for pervasive computation system.
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NoC Routing Algorithm Based on 16-node PRDT
DUAN Xinming; YANG Yulu; YANG Mei
Computer Engineering    2007, 33 (09): 12-14,1.  
Abstract9405)      PDF (226KB)(1220)      

The interconnection network plays an important role in performance and energy consumption of a Network-on-chip(NoC) system. PRDT(2,1) is a promising solution for the interconnection network of NoC due to its smaller diameter and average distance, constant node degree and full scalability. In this paper, a binary routing algorithm for PRDT is presented in order to improve the performance of routing for PRDT with small size. In the case that PRDT consists of no more than 16 nodes, the binary algorithm is deadlock-free without the utilization of virtual channels. Based on the binary algorithm, it proposes a fully adaptive routing algorithm which is deadlock-free by using a few virtual channels. The comparison between the deterministic, adaptive binary algorithm and the original vector algorithm is conducted in a simulation. The results show that the binary algorithm is better in performance while its hardware cost is lower. So the algorithm is readily applicable to the small PRDT-based NoC systems.

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Cited: Baidu(2)
Texture Feature Classification Based on LMCP Method
CHEN Heng-Xin, TANG Yuan-Tan, FANG Bin, ZHANG Ta-Beng
Computer Engineering    2011, 37 (24): 16-17.   DOI: 10.3969/j.issn.1000-3428.2011.24.006
Abstract8736)      PDF (360KB)(1466)      
The Local Binary Pattern(LBP) method does not consider the contrast value between neighbor pixels, so the feature representation ability of LBP method is limited. According to the problem, this paper proposes a Local Multi-layer Contrast Pattern(LMCP) method to overcome this disadvantage. It limits the illumination variation and divides the contrast value range between neighbor pixels in local area into several layers. Every contrast value is mapped into a certain layer. The statistic histogram for every contrast layer is constructed using the same idea as LBP method. In order to solve the problem of expanded feature dimension, it adopts statistics mapping method to reduce the histogram bins. Experimental result based on Outex_TC_00012 texture database proves that the LMCP method has good classification effect.
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Mobile Network Secure Routing Scheme Based on MCPK
MA Jiang-Chao, WANG Yan-Jun
Computer Engineering    2011, 37 (12): 107-109.   DOI: 10.3969/j.issn.1000-3428.2011.12.036
Abstract8629)      PDF (275KB)(1021)      
For mobile Ad Hoc networks vulnerable to wormhole attack problem, it proposes a routing protocol based on the best links——MSRP secure routing protocols, including the neighbor detection, authentication, key negotiation and communication process, to seek balance between security and performance in the case of the settlement agreement in OLSR security problems. MCPK-based security with routing protocols, OLSR neighbor detection stage by the introduction of secure authentication mechanisms to prevent wormhole attacks. Experimental results show that with the increase in the length of an encrypted channel, wormhole attack detection rate is significantly increased, the solution can better prevent and detect wormhole attacks.
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Clustering Integration of Collaborative Ontologies Based on EOWL
XIAO Ruliang; TANG Shengqun
Computer Engineering    2007, 33 (12): 211-213.   DOI: 10.3969/j.issn.1000-3428.2007.12.074
Abstract8602)      PDF (164KB)(741)      
Ontologies usually collaborate with each other. The standard OWL, only remains the owl:import interface, where anything can be imported completely. A clustering integrated collaboration is proposed for ontologies. It differs from current OWL which is extended (EOWL) by adding some new collaborative interfaces instead of using owl:import and so on. A clustered and layered collaborative management system is proposed for context track and reasoning for OWL-DL. It expands the OWL to EOWL and presents a solution of collaboration between ontologies and foreign ontologies in view of ontological language itself.
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TVAC Test Method of Synchronous Full Scan Sequential Circuits
JIN Li-Yun, KUANG Ji-Shun, WANG Wei-Zheng
Computer Engineering    2011, 37 (12): 268-269,272.   DOI: 10.3969/j.issn.1000-3428.2011.12.090
Abstract8385)      PDF (219KB)(860)      

Test Vectors Applied by Circuit-under-test itself(TVAC) is a new Built-in Self-test(BIST) scheme. Two different TVAC structures for synchronous full scan sequential circuits are presented. Experimental results on ISCAS89 benchmark circuits demonstrate that, compared with the weighted-random-pattern test and Circular Self-test Path(CSTP) method, the TVAC scheme can reach higher fault coverage with smaller test vectors.

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Maximum Lifetime Model of Heterogeneous WSN in Hexagon Coverage Condition
LI Xue, HE Yu-Yao, WU Ai-Sheng
Computer Engineering    2011, 37 (18): 12-15.   DOI: 10.3969/j.issn.1000-3428.2011.18.005
Abstract8374)      PDF (312KB)(969)      
The heterogeneous surveillance sensor network energy consumption model which can balance the energy consumption and maximize the network lifetime is established. Based on the model and considering the factors of node energy restriction and data integrality, the network lifetime model of heterogeneous surveillance sensor network in hexagon coverage condition is presented. The optimal solution of the network lifetime model is obtained in hexagon coverage condition when the intra-cluster and inter-cluster key nodes almost run out of energy at the same time. Based on the network lifetime model, the minimum node density for satisfying a given lifetime constraint is gotten.
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Cited: Baidu(2) CSCD(1)
Formal Description of TCP Protocol Based on Timed Colored Petri Net
HE Zhong-Yang, LI Ou, YANG Bai-Wei, LIU Xiang
Computer Engineering    2011, 37 (18): 77-80.   DOI: 10.3969/j.issn.1000-3428.2011.18.026
Abstract8336)      PDF (316KB)(1211)      
This paper proposes a formal description method of TCP protocol based on Timed Colored Petri Net(TCPN). Three parameters of sequence number, confirmation number and data unit are adopted to describe the packet more accurately. A time parameter is introduced to evaluate the performance of the protocol. The model is closer to the actual running order agreement because of timeout retransmission, flow control and validation data piggyback transmission. CPN Tools is used for modeling dynamic simulation, and its result proves the correctness of the model.
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Study on Network Intrusion Detection Based on TSVM
XU Wenlong; YAO Lihong; PAN Li; NI Yousheng
Computer Engineering    2006, 32 (18): 138-140.   DOI: 10.3969/j.issn.1000-3428.2006.18.050
Abstract8246)      PDF (131KB)(1111)      
Transductive support vector machines (TSVM) classifies the new data vector based on the information only related to this data vector. This paper proposes an anomaly network traffic detection method based on TSVM. The KDD-99 intrusion detection competition data set is used to illustrate the performances of the TSVM. The performance-comparisons of TSVM and traditional inductive SVM are presented. The results show that TSVM can be used in intrusion detection practically.
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Cited: Baidu(4) CSCD(2)
Application of Quantum Neural Networks in Proportion Integration Differentiation Parameters Adjustment
CAO Mao-Dun, LI Fen-Che, XIAO Gong
Computer Engineering    2011, 37 (12): 182-184.   DOI: 10.3969/j.issn.1000-3428.2011.12.061
Abstract8188)      PDF (285KB)(830)      

This paper presents an online adjusting method of Proportion Integration Differentiation(PID) parameters based on Quantum Neural Networks(QNNs). By designing a controlled quantum rotation gate, a quantum neuron model is constructed, including two kinds of design parameters: rotation angle of qubits phase and its control range. A quantum neural networks model based on quantum neuron is proposed. By using gradient descent algorithm, a learning algorithm of the model is designed. Experimental results show that both the adjusting ability and the stability of QNNs model are superior to that of the Back Propagation(BP) networks.

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Cited: Baidu(4) CSCD(1)
Optimization of Network Multipath Traffic Based on DEMT Algorithm
YANG Su-ying; WANG Jin-cheng; PIAO Hong-yan
Computer Engineering    2009, 35 (13): 99-101,.   DOI: 10.3969/j.issn.1000-3428.2009.13.034
Abstract8171)      PDF (394KB)(811)      
A new algorithm is put forward in Dynamic Equilibrium of Multipath Traffic(DEMT) for the purpose of solving the shortcomings of the load distributing multipath algorithm. According to topological structure of putting vector weight, a mathematical model of distributing multipath is set up on network traffic. In this algorithm, the probability coefficient is constructed and it is regarded as the standards of select path, and the load rate variable and the least hop variable on QoS attribute is injected to deduce a optimizing algorithm of more reasonable equilibrium of the network resource. The simulation results show that the new method can avoid network congestion. Network traffic rate is controlled less than 70% and total delay time is reduced to 56% correspondingly.
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Cited: Baidu(2)
PBMB Algorithm Based on Message Transfer Between Date Replica in P2P Network
WANG Wen-fang; XU Guang-ping; LIU Jing
Computer Engineering    2008, 34 (11): 49-51.   DOI: 10.3969/j.issn.1000-3428.2008.11.018
Abstract8091)      PDF (108KB)(953)      
Large-scale storage system based on P2P architecture is proposed to provide reliable and effective storage service. In these systems, the replica of data object is used to improve performance, availability and reliability. When data object changes in one of the replicas, data must be transferred to other replicas. This paper proposes a application layer multicast protocol——PBMB. Node in the system is grouped by BID. Messages are transferred by PBMB using a novel method. PBMB is self-organized, and can be used in WAN environment. Simulation shows that the algorithm is stable even in large-scale system. Messages are transferred effectively while using less node resources. PBMB is suitable for real systems in the Internet.
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Cited: Baidu(1) CSCD(1)
OAI-PMH Service Provider Framework Based on FIHC
WANG Xin-bo; CHEN Li-chao; XIE Bin-hong; XIA Mei
Computer Engineering    2010, 36 (3): 263-265.   DOI: 10.3969/j.issn.1000-3428.2010.03.089
Abstract8030)      PDF (341KB)(761)      

Aiming at the organizational problem of metadata harvested by the service provider, this paper proposes Open Archives Initiative Protocol for Metadata Harvesting(OAI-PMH) service provider framework based on Frequent Itemset-based Hierarchical Clustering(FIHC). It utilizes FIHC module to cluster the metadata and generate a cluster tree. Experimental result shows that this framework can reasonably organize metadata, improve metadata search speed and be convenient for user to browse metadata by category.

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Cited: Baidu(2)
Trust Evaluation Model GTruMod for Grid Environments
LU Wei-qin; ZHANG Yu; LI Jian-xin; LIU Xu-dong
Computer Engineering    2008, 34 (5): 139-141,.   DOI: 10.3969/j.issn.1000-3428.2008.05.048
Abstract7971)      PDF (147KB)(873)      
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.
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Cited: Baidu(3)
Hierarchical Memory Fault-injection Method for Itanium Architecture
WANG Bei, ZUO De-Cheng, JIAN Jun, ZHANG Zhan
Computer Engineering    2012, 38 (04): 70-72.   DOI: 10.3969/j.issn.1000-3428.2012.04.023
Abstract7965)      PDF (254KB)(6904)      
In order to figure out how memory faults affect high-performance servers, this paper presents a multi-layer fault injection method for Itanium architecture computers. HMFI(Hierarchical Memory Fault Injector) is designed and developed to inject memory faults in physical level, operating system kernel level and process level. Experimental results demonstrate the effectiveness of HMFI in evaluating the fault-tolerant properties of complex computer system.
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Cited: Baidu(1) CSCD(1)
Web Page Classification Method Based on RSOM-Bayes
FENG He-long; XIA Sheng-ping
Computer Engineering    2008, 34 (13): 61-63.   DOI: 10.3969/j.issn.1000-3428.2008.13.023
Abstract7926)      PDF (238KB)(1094)      
Most Web page classification methods are based on Vector Space Model(VSM), but it is not suitable for large scale application background with bad computation complexity. A new automated text classification method based on RSOM neural net tree and Bayes method is proposed, RSOM neural net tree is used in Web page index and Bayes method is used in automated Web page classification. The excellent performance of this method has been tested in feature dimension, performance, capacity and accuracy.
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Cited: Baidu(8) CSCD(1)
Optimization Analysis of Workflow Model Based on WDAG
WEN Jun-hao; QIN Jia; ZHAO Rui-feng
Computer Engineering    2010, 36 (1): 30-32.   DOI: 10.3969/j.issn.1000-3428.2010.01.011
Abstract7884)      PDF (395KB)(1087)      
In order to optimize the process execution and reduce the actual cost for operation, optimization of workflow is analyzed in the form of Weighted Direct Acyclic Graph(WDAG). By mapping the nodes, arcs, weights of the WDAG to the events, operations, cost of workflow model correspondingly, this paper constructs a workflow model based on WDAG. It proposes an optimization algorithm that involved two strategies, consolidation optimization and parallel optimization to aim at the sequence process which happens most frequently in workflow. Simulation experimental result proves the validity of the algorithm.
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Cited: Baidu(5) CSCD(2)
Construction Method of Timed Automata for ICPN
LIAO Wei-Zhi, LI Wen-Jing, WANG Ru-Liang
Computer Engineering    2011, 37 (6): 15-17.   DOI: 10.3969/j.issn.1000-3428.2011.06.006
Abstract7876)      PDF (268KB)(900)      
Behavior evolution is main method for Continuous Petri Net(CPN) model. However, it can not offer all analysis for CPN. To analyze Interval Continuous Petri Net(ICPN) by timed automata, the state evolution graph for ICPN is developed, and the timed automata for ICPN is proposed based on a state evolution graph. Through case study, the effectiveness and necessity of the proposed method are illustrated.
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Product Conceptual Design Approach Based on Hybrid Mechanism of FCBR and AHP
CHEN Yang
Computer Engineering    2008, 34 (9): 227-229.   DOI: 10.3969/j.issn.1000-3428.2008.09.082
Abstract7836)      PDF (138KB)(915)      
This paper constructs a system structure which is used for conceptual design on the basis of FCBR and AHP. The structure combines the fuzzy set theory with CBR to solve the problem that most design requirements described by users are uncertain and nonstandard. After retrieving the competent evaluation cases set, the system uses AHP method to evaluate the function and economy indexes of the cases set, attains the most appropriate design candidate, and achieves the final optimized scheme by transfering the adaptation rules of the function adaptation cases to modify the design candidate. The application result shows that the hybrid mechanism can provide the designers with effective design decision during conceptual design.
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Hierarchical Network Management in Mobile Ad Hoc Based on IZRP
XIAO Ying-jie; XIAO Zong-shui; SU Ji-bin
Computer Engineering    2009, 35 (13): 114-116.   DOI: 10.3969/j.issn.1000-3428.2009.13.039
Abstract7784)      PDF (386KB)(845)      
Because of the special environment of the mobile Ad Hoc, the management of it becomes very difficult. Aiming at this, by using the new zone generating algorithm, this paper proposes IZRP based on ZRP, which reduces the zones’ number and lessens the nodes’ overlap attach. The hierarchical network management based on IZRP shortens the time of routing transmit and enhances the management efficiency of the whole Ad Hoc network.
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Cited: Baidu(2) CSCD(1)
Multi-user Roam System Based on JSAI
WEN Bo; LI Zhong-yi
Computer Engineering    2008, 34 (17): 269-270,.   DOI: 10.3969/j.issn.1000-3428.2008.17.096
Abstract7735)      PDF (130KB)(815)      
This paper presents a framework of multi-user roam system based on B/S architecture. The scene can be dynamically controlled by using Java script authoring interface of VRML. With messages transferred between the server and clients from the users and the scene itself, the communication and interaction among multiple users in the same virtual scene on the web are implemented. This system is also a general ideal model for other multi-user roam systems. An example of this application is showed, and the result shows this system is effective.
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Reliability Analysis of Avionic System Based on Vague Fault Tree
ZHANG Chao; MA Cun-bao; SONG Dong; XU Jia-dong
Computer Engineering    2008, 34 (7): 254-256.   DOI: 10.3969/j.issn.1000-3428.2008.07.090
Abstract7686)      PDF (186KB)(914)      
Because most avionic equipments have abnormal states and its failure behaviors are always characterized in uncertainty, it is very difficult to analyze its reliability by Fault Tree Analysis(FTA) model which is based on probability theory. To solve this problem, the failure behaviors of bottom events are represented by triangle Vague sets, and the AND/OR fuzzy operators are built based on arithmetic operations of triangle Vague sets, and sequentially the Vague Fault Tree Analysis(VFTA) model is proposed. Three FTA models are adopted respectively to analyze the reliability of a DC system, and the comparisons show that the proposed VFTA model is more flexible and more effective than the other fuzzy FTA models.
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Cited: Baidu(2) CSCD(1)
Study of Supply Chain Performance Evaluation Based on IHSA_LSSVM
LU Shi-chang, YUAN Duo-ning, YANG Xiao-tao
Computer Engineering    DOI: 10.3969/j.issn.1000-3428.2014.06.062
An Executable Object Structural Model Based on OOPN
LIN Yi; YAN Jie; ZENG Xiaohui; ZHANG Kai
Computer Engineering    2007, 33 (13): 13-15.   DOI: 10.3969/j.issn.1000-3428.2007.13.005
Abstract7662)      PDF (114KB)(956)      
This paper points out the shortage of the lack of unified semantic foundation among UML multi-views, and presents an object-oriented Petri net (OOPN) based approach, executable object structural model (EOSM), to deal with it. This method represents both the aspects of objects’ structure and behaviors in the form of sub-net of OOPN, so that behaviors belonging to different objects can be coupled dynamically upon ESOM models. Simulation of an example shows that EOSM can unify the structural and behavioral models successfully.
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Cited: Baidu(2)
Data Exchange Model and Integrity Check Mechanism of Electronic Flight Bag System
YANG Hong-Yu, LI Dong-Bo
Computer Engineering    2012, 38 (01): 29-32.   DOI: 10.3969/j.issn.1000-3428.2012.01.007
Abstract7572)      PDF (292KB)(1114)      

This paper presents a data exchange model of Electronic Flight Bag System(EFBS). This model uses star-type logic structure to implement data transfer, and exchanges the message through data exchange components and central content management elements, then implements EFBS message exchange through a data exchange procedure designed with XML. A data integrity exchange procedure and an integrity check mechanism of EFBS are presented. In this mechanism, the sender generates digital signatures with DSA algorithm and the text summary is calculated by SHA-1 algorithm. At the receiver, the data integrity checking operation is conducted through digital signature verification consequently. Experimental results demonstrate the effectiveness and feasibility of this EFBS data integrity checking mechanism.

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Modeling and Analysis of Aspect-oriented NVP Based on HCPN
SUN Xiao-Xing, YU Hui-Qun
Computer Engineering    2012, 38 (16): 61-64.   DOI: 10.3969/j.issn.1000-3428.2012.16.015
Abstract7499)      PDF (299KB)(947)      
Aiming at detecting the design faults at early development stage and reducing the overhead that N-version Programming(NVP) fault tolerance strategy may bring into a system, this paper proposes an aspect-oriented modeling method based on Hierarchical Colored Petri Net(HCPN). NVP is modularized into an aspect sub-module and woven into a final executable HCPN. An aspect-oriented NVP model is built through a case study of searching system using this method. Analysis result verifies the correctness and effectiveness of this NVP model.
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Dynamic TXOP Allocation Method in WLAN
CHEN Chen; GAO Xin-bo; ZHANG Su-bing; FAN Ke-feng
Computer Engineering    2010, 36 (7): 11-13.   DOI: 10.3969/j.issn.1000-3428.2010.07.004
Abstract7398)      PDF (421KB)(1307)      
In order to solve the fairness problem in 802.11e networks, a method called DTAF(Dynamic TXOP Allocation for Fairness) is proposed, which utilizes the collision times to estimate contention degree before transmission, turns TXOP, and at the same time, solves the unfairness problem in the networks employing the multi-rate scheme. Theoretic analysis and simulaiton results show that DTAF has better performance in retransmission times, packets average transmission delay and fairness among stations employing varying data rates.
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Cited: Baidu(4) CSCD(2)
Group Key Management Scheme Based on Threshold
TUN Hao-Tian, CHEN Huo, TAN Feng-Hu, DAI Yang-Huan
Computer Engineering    2013, 39 (3): 167-173.   DOI: 10.3969/j.issn.1000-3428.2013.03.033
Abstract7363)      PDF (350KB)(874)      
This paper proposes a Group Key Management Scheme Based on Threshold(GKMT). The idea of dynamic threshold secret sharing scheme to encrypt multicast streams is used in GKMT. When a user wants to join or leave a multicast group, it is need not to redistribute group key. It can greatly enhance the effectiveness of the scheme. Meanwhile, to enhance the scalability of the scheme, the original scheme is improved to LGKMT using the hierarchical control. Performance analysis result shows that GKMT and LGKMT schemes are superior to existing group key management scheme on key communication cost, suitable for the group communication network which group state often changes.
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Cited: Baidu(2) CSCD(1)
Reconstruction Algorithm of Chirp Matrix Sampling Based on DCFT
BAI Lu-ping,MA Li-hong,LI Qing-long
Computer Engineering    DOI: 10.3969/j.issn.1000-3428.2014.08.036
Compressed Storage for C-Temporal Relation Data Model Based on Improved Genetic Algorithm
WANG Zhi-wen; LIU Mei-zhen; CAI Qi-xian; XIE Guo-qing
Computer Engineering    2009, 35 (21): 178-180.   DOI: 10.3969/j.issn.1000-3428.2009.21.059
Abstract7264)           
There is data redundancy temporal database and the quantities of temporal database are increasing fleetly, aiming at these problems, this paper puts forward compressed storage tactics based on improved genetic algorithm for temporal data which combine compress technology in existence in order to settle data redundancy in the course of temporal data storage. Temporal relation data at any moment is decomposed into least granularity data and be coded meanwhile. Optimized storage data are figured out by using improved genetic algorithm, and the ratio of compression is enhanced. Celerity astringency of the algorithm can heighten speed of removing data redundancy largely.
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Cited: CSCD(1)
Analysis and Improvement of Group Key Agreement Protocol ID-AGKA
LI Guo-min; HE Da-ke;
Computer Engineering    2009, 35 (6): 148-149.   DOI: 10.3969/j.issn.1000-3428.2009.06.051
Abstract7212)      PDF (108KB)(1112)      
A more security analysis on the ID-based Authenticated Group Key Agreement(ID-AGKA) is given and it is found that the ID-based AGKA does not resist outsider attack, that is, an adversary can make a group session key inconsistent, which can not be detected by the users in the group however. An improvement of the AGKA scheme is proposed. Security analysis shows the scheme can resist outside attack.
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Cited: Baidu(5) CSCD(1)
ACJT Group Blind Signature Scheme
ZHONG Jun; HE Dake
Computer Engineering    2007, 33 (01): 19-21.   DOI: 10.3969/j.issn.1000-3428.2007.01.007
Abstract7194)      PDF (193KB)(1020)      
This paper constructs a new group blind signature scheme on the basis of ACJT group signature scheme. The security of the new scheme is based on the strong RSA assumption and the decisional Diffie-Hellman assumption, of which is different from the scheme of LR98. In the mean time, the efficiency of the user to blind the content of the signer is improved. To blind the group signature of ACJT, this paper only adds the computation of modular exponentiation and modular addition; while the scheme in LR98 adds the computation of double discrete logarithm, root of the discrete logarithm and random permutation in order to blind the group signature of CS97. As a result, the scheme proposed by this paper is much lower than the one in LR98 with respect to computation complexity and higher with respect to efficiency.
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Cited: Baidu(8)
New Weighted Fair Queue Scheduling Algorithm
YIN De-bin; XIE Jian-ying
Computer Engineering    2008, 34 (4): 28-30.   DOI: 10.3969/j.issn.1000-3428.2008.04.010
Abstract7174)      PDF (341KB)(2052)      
Traditional weighted fair queue algorithms have the main drawback: the calculation of the weight parameters according to each packet. The paper proposes a new weighted fair queueing algorithm(SPFQ), which uses service probability to schedule packets and a random number to decide which packet to be served next. In addition, a novel adaptive service probability parameter calculation method is used to solve the unfair problem induced by the variable packet length and an adaptive queue management technology to improve the utilization of the server’s queue buffer and reduce the delay burstiness. Simulation results demonstrate the validity and practicability of SPFQ.
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Cited: Baidu(9)
SMTP Transparent Proxy Server for Security Detection
ZENG Xin-zhou; WANG Yong-jun; CHEN San-long
Computer Engineering    2007, 33 (17): 184-186.   DOI: 10.3969/j.issn.1000-3428.2007.17.063
Abstract7146)      PDF (93KB)(1198)      
On the basis of the analysis of SMTP protocol and SMTP proxy server principle, a SMTP transparent proxy for security detection is developed under Linux environment. Some key techniques are designed and implemented, such as redirecting port, concurrent mail service, getting the address and port of the server, handling annex. System test shows that the SMTP proxy is transparent to users, and can deputize for multiple e-mail services, prevent virus intrusion and leakage of internal content efficiently.
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Design for Reconfigurable Test Unit Adapter of Automatic Test System
FU Xin-hua; XIAO Ming-qing; ZHOU Yue-wen; KONG Qing-chun
Computer Engineering    2010, 36 (2): 225-228.   DOI: 10.3969/j.issn.1000-3428.2010.02.080
Abstract7110)      PDF (298KB)(908)      
This paper proposes a thought of Reconfigurable Test Unit Adapter(RTUA). RTUA can be configured in real-time with programmable interface to satisfy the test requirements of different UUTs or signals. A kind of matching function is presented to describe the matching degree between test point and instrument port. Matching function integrates signal properties of test point, capability parameters of instrument and instrument’s price and so on. Hardware architecture of RTUA is put forward. Control module is implemented with SOPC and can be configured with different configuration files. Software design method of RTUA is given, test and control computer realizes the configuration management of RTUA with COM.
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Cited: Baidu(11) CSCD(9)
Children Interaction Role Mining Method Based on KMHC Algorithm
HE Jing, WANG Lei, ZHOU Chi, WANG Rui
Computer Engineering    2012, 38 (19): 188-190,194.   DOI: 10.3969/j.issn.1000-3428.2012.19.048
Abstract7108)      PDF (278KB)(646)      
In order to solve this problem that the number of character classes is unknown, and the large number of data in process of children using computer-education system, this paper presents a kind of method based on K-means Hierarchical Clustering(KMHC) algorithm to dig the children’s roles of the interaction. This method preprocess the data by using data cleaning with constraints and data changes with rules. After preprocess, this method uses K-means clustering method of interactive children in supplementary roles in the process of initial clustering, and uses the hierarchical clustering method to classify the initial results. Experimental results show that the classification of this method is better, and has good efficiency.
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PGSC Modeling Method for Broadband Power Amplifier and Pre-distortion Research
NAN Jing-chang, QU Yun, GAO Ming-ming
Computer Engineering    DOI: 10.3969/j.issn.1000-3428.2014.02.022
Research on Reverse Nearest Neighbor Queries Technique for Moving Objects
WANG Xiao-Hui, CAO Ze-Wen, TAN Chuan-Shu
Computer Engineering    2010, 36 (20): 66-67.   DOI: 10.3969/j.issn.1000-3428.2010.20.023
Abstract7027)      PDF (80KB)(1783)      

This paper presents a Reverse Nearest Neighbor Queries(RNNQ) algorithm based on Auto-Selection Grid Index(ASGI). ASGI divides the space into an equal size network, and each cell stores moving objects as a bucket. RNNQ algorithm uses the strategy of the bucket’s object number and the grid geometry characteristic to reduce the access node the RNNQ must visit. ASGI will repeat the previous action to decrease the cost again if objects around the query point are too many. Experimental results show that RNNQ algorithm based on ASGI has good query performance and outperforms RNNQ algorithm based on TPR tree.

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Cited: Baidu(2) CSCD(1)
Attribute Reduction Method Based on Extended Kullback-Leibler Distance
ZHOU Ruqi; CHEN Wenwei
Computer Engineering    2007, 33 (11): 62-63.   DOI: 10.3969/j.issn.1000-3428.2007.11.023
Abstract6771)      PDF (106KB)(1249)      
Kullback-Leibler distance of information can be used to measure the difference degree between the random variables. This paper presents the concept of extended Kullback-Leibler distance. A new reduction algorithm based on extended Kullback-Leibler distance for knowledge is put forward, and the complexity of the algorithm is analyzed simply. The experimental results show that this algorithm can find out the relative minimal reduction for most decision tables.
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Safety Analysis Method for Process Control Systems Based on Process Control Event Diagram
YAN Zhao-lin; RAN Cheng-xin; LIU Jing-jun
Computer Engineering    2009, 35 (22): 122-124.   DOI: 10.3969/j.issn.1000-3428.2009.22.042
Abstract6761)      PDF (128KB)(938)      
Aiming at the deficiencies in applying traditional safety analysis technologies, this paper presents a safety analysis method based on Process Control Event Diagram(PCED) for control logic in Computer Process Control Systems(CPCS). The PCED of its control logic is set up according to the characteristics of the system, the influencing path of “Action-Component-Variable” is erected, and the safety of the control logic is analyzed by the algorithm. The method is illustrated by a case study of the computer-controlled chemical process system.
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Cited: Baidu(1) CSCD(1)
Data Fitting Method of ACPH Distributions Based on EM Algorithm
HUANG Zhuo; PAN Xiao; GUO Bo
Computer Engineering    2008, 34 (4): 75-78.   DOI: 10.3969/j.issn.1000-3428.2008.04.026
Abstract6699)      PDF (325KB)(955)      
ACPH(Acyclic Continuous Phase-type) distribution inherits the better characteristic form Phase-type(PH) distribution. The difficulty in fitting data with ACPH distribution is lower than that with PH one. To solve the numerical instability problem existed in the current ACPH data fitting methods, a new ACPH data fit method based on EM algorithm is proposed. The theoretical analysis process of the new method is given. The effectiveness of the new method is verified by three examples.
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-NAFw Decomposition of Scalar Multiplication of ECC

DING Yong;
Computer Engineering    2009, 35 (8): 169-170.   DOI: 10.3969/j.issn.1000-3428.2009.08.057
Abstract6666)      PDF (239KB)(978)      
For fast computation of scalar multiplication of the elliptic curve over GF(p), with the utilization of the endomorphism whose characteristic polynomial is , -NAF expansion of the integer k is proposed by Ciet in order to speed up the computation of scalar multiplication kP. In this paper, a window technic is applied to the -NAF representation, which gets the -NAF decomposition of k and can obtain better result than -NAF representation with the cost of some quantities of storages. The length and the density of the expansion is accurately estimated.

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Improved DTRA Protocol Based on Slot Schedule
LI Hong-Sheng, LI Ying, WANG Wei
Computer Engineering    2011, 37 (5): 118-120,123.   DOI: 10.3969/j.issn.1000-3428.2011.05.040
Abstract6599)      PDF (248KB)(1141)      
This paper proposes an improved Directional Transmission and Reception Algorithm(DTRA) named SDTRA protocol based on slot schedule. In the process of neighbor discovery stage, the protocol decreases the collision through sending time random delay. In the process of slot schedule stage, it adopts greedy edge coloring algorithm to control the time the node can use. The protocol can assure the QoS support through synchronous slot schedule algorithm. Simulation results show that the improved DTRA protocol is much better than DTRA protocol in neighbor discovery, time utility and throughput.
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Cited: Baidu(2) CSCD(1)