Journal of Computer Applications

Quantum-particle swarm algorithm for optimizing high-dimension functions

2007, (12): 2885-2887.

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An advanced quantum-particle algorithm was presented to solve the problem of the curse of dimensionality. The quantum-particle algorithm which has high-dimensional problem used multiple swarms to optimize different components of the solution vector by co-learning method and helped the algorithm break away from the curse of dimensionality to find the global optimal solution. Furthermore, in every iteration, we adopted the fitness function from genetic algorithm to select the number of the particles to reduce the time. The experimental results of classic functions show that the improved hybrid method keeps the balance between the global search and local search.

Adaptive division particle swarm optimization for engineering constrained optimization problem

Jin Lu xiao renbin

2007, (12): 2888-2891.

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A new algorithm architecture was proposed. In order to adjust effectively the ratio of exploration subgroup versus exploitation one, the algorithm adopted the centralized processing technique to construct the local environment factor, and balanced the local and global search capabilities of the algorithm. Furthermore, compared with other improved intelligent algorithms, experimental results got from the application and verification of real constrained engineering design problem indicate that the algorithm performs better in terms of accuracy, efficiency and robustness.

Solving task assignment problem based on improved particle swarm optimization algorithm

tan wenfang zhao qiang yu shengyang xiao renbin

2007, (12): 2892-2895.

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Task assignment problem is a typical NP problem. Particle Swarm Optimization (PSO) algorithm was used to solve task assignment problem. The model of task assignment problem was formulated and the detailed solution for solving task assignment problem based on PSO algorithm was illuminated. To get better optimization results, an improved PSO algorithm named IPSO including variance mechanism and local updating mechanism was presented. Examples and simulation experiences demonstrate that the IPSO algorithm is effective in solving task assignment problem.

Revision method for imbalanced support vector machines

Jin-Yan WANG Wan-Li LIU

2007, (12): 2896-2898.

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A revision method was proposed for the offset of separation hyperplane of binary-classification imbalanced data in Support Vector Machine (SVM). Firstly, the principal values were found respectively of the two classes of samples in feature space by using Kernel Principal Component Analysis (KPCA). Secondly, one penalty proportion was given based on the information provided by the sizes of the two sample data and their values. Finally, a new separation hyperplane was generated through the optimization training. The hyperplane revised the error of the standard support vector machines. Experiment results prove the validity of the method. Compared with standard support vector machines, the proposed method can not only balance but also decrease the classification error.

Adaptive S plane control algorithm for underwater vehicles based on single neuron cell

Jian-Guo WANG

2007, (12): 2899-2901.

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Based on the analysis of fuzzy control, the S plane control that was formed with reference to PID control does not have self-learning ability. In order to improve the adaptability and dynamic response ability of Autonomous Underwater Vehicle (AUV), the adaptive S plane control algorithm based on single neuron cell was introduced and the control parameters self adjustment was achieved and the added integral item also improved the dynamic response ability of AUV. Experimental results and application prove that the nonlinear control method has the merits of quick response, small overshoot, better self-learning and simple design and so on.

Model of Chinese words rough segmentation based on bi-gram and N-most-probability method

Chun-Ying WU

2007, (12): 2902-2905.

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Words rough segmentation is an important foundation of Chinese words segmentation. At present, the commonly used rough segmentation model is based on non-statistical model or uni-gram statistical model, and the latter has obtained a good effect. Based on the uni-gram model, a new model of rough segmentation, which is based on bi-gram and N-most probably method, was proposed. In this model, all possible words were segmented into directly acyclic graph at first, and then the probability was calculated using the noise-channel model and bi-gram model, the data sparse problem was solved through interpolation smooth technology to obtain few high recalling rate and high efficient rough result, which tried to cover the correct segmentation and unknown words as much as possible such that the quality for the following segmentation could be enhanced. The theoretical analysis, the model establishment and the preliminary experiment show that this model is effective for words rough segmentation.

Fuzzy constraint-based model for multiple concurrent bi-lateral negotiations

2007, (12): 2906-2909.

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To obtain a particular resource or service, consumer may engage in multiple concurrent bi-lateral negotiations with several providers for a most satisfied deal. A fuzzy constraint-based model was developed for this multiple concurrent negotiations. In this model, the consumers' requirements and preferences were expressed by fuzzy constraints, and they could adopt three negotiation strategies based on the idea of PFCSP （Prioritized Fuzzy Constraints Satisfaction Problem） to evaluate the proposals from their opponents or made counter-proposals themselves. In addition, different coordination strategies were designed to coordinate multiple bi-lateral negotiation threads. At last, the validity of the model was experimentally verified and varieties of negotiation strategies and coordination strategies were compared.

Wavelet chaotic neural network for function optimization

ZhenHong Jia

2007, (12): 2910-2912.

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Chaotic neural network can solve function optimization problems effectively. A wavelet chaotic neural network was proposed by transferring sigmoid function to Mexican hat wavelet function and the single-parameter annealing function being replaced by subsection exponential simulated annealing functions. In contrast to the conventional chaotic neural network, it has a much higher ability to find the global optimal value. The simulation results show that on rapidity and accuracy of searching for the globally optimal solution, this wavelet chaotic neural network is obviously superior to conventional chaotic neural network models.

Shooting algorithm based on optimal search in robot soccer

Yong Pu Xingshe Zhou Yuying Wang

2007, (12): 2913-2915.

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In the robot soccer competition, the ball's moving status is always changing and fluky because of the shoving and friction. In most cases, it is very difficult to find a global optimal shooting path, or the planning path can not be achieved by the robot in time. The new shooting method based on object function could find out the optimal path in current moving status, which ensures the robot to approach the ball according to the given angle, through an optimal search in the area that the robot can reach. This algorithm can fit to various speed statuses, improve the success rate of shoot, and react to the sudden changing of the ball's moving status. In all competitions, it is common to make a switch between different control algorithms, but the robot is likely to fall across an oscillation relative to the ball's situation due to the deferent velocity jump from the different control algorithms. According to the method which used the distance as a judge condition for algorithm switching, the dithering phenomenon by reason of different control algorithms was deep analyzed, and avoided by using a S- curve weighted algorithm, and the smooth-switch between different control algorithms on the switch borderline was realized.

Learning algorithm for cascade RBF-LBF neural networks based on clustering

2007, (12): 2916-2918.

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To enhance the generalization ability of the network, a kind of cascade RBF-LBF neural networks consisting of single-lager Radial Basis Function (RBF) and Linear Basis Function (LBF) networks was proposed, and a pattern-based clustering of cascade RBF-LBF neural networks structure learning algorithm was presented. The input of RBF and LBF neural networks was trained by using pattern clustering to determine the initial structure of the network. Then the samples were adjusted in wrong class to overlap or merge the kernel function. Experiment of two spirals problem proves that the algorithm has higher generalization ability and needs shorter training time.

Semantic similarity match of ontology concept based on heuristic rules

Yang Zhe

2007, (12): 2919-2921.

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In the hierarchy model of ontology conceptual model, the semantic similarity between two ontology concepts is in inverse proportion to the semantic distance in between. At the same time, the closer the concepts are to the bottom in the hierarchy model, the more information they describe. Therefore, if the deeper the nearest shared ancestor is, the more similar the two concepts are. Considering these two factors, two heuristic rules and the calculating formula were constructed. And the formula was proved reasonable by analyzing an ontology instance. In the formula, there were two experimental parameters, that were decided by the depth of the hierarchy model of ontology. According to the depth at present, the reasonable values of two experimental parameters were given.

Feature selection based on immune particle swarm optimization

2007, (12): 2922-2924.

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Concerning the data set with high dimensions in intrusion detection, an Immune_PSO algorithm based on immune and particle swarm optimization was proposed, which can select the most important features for intrusion detection, eliminate the redundancy property, reduce the problem size, improve the quality of classification and speed up the detection. The position of the particle was expressed with a binary string in Immune_PSO algorithm, and the selection of the particles was achieved by immune algorithm which can retain the diversity of particle and enhance the convergence results of PSO. The experiments with the KDD CUP1999 show that the proposed algorithm is efficient for feature selection.

Research of cross-certificate model based on Agent mechanism

2007, (12): 2925-2927.

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After studying the general cross-certificate model, an interoperation model based on Agent mechanism was proposed to relieve the complexity of path construction in network trust model. The model realized the connection between network model and tree model without the third party and thereby making up for BCA's shortcomings partly. Sub-structure multipath method was used to improve the efficiency of the path construction, and the efficiency of the path construction algorithm was certified by examples.

On study of the framework of the authentication property design

2007, (12): 2928-2930.

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A method to design the authentication property of the security protocols is presented in this paper. The message structures for the authentication goal are designed. With the help of the channel-model, the dynamic characteristics of security property are added to the designing-process. This method uses the trace-model to accurately depict the message exchange. The design principles for avoiding the attack on the security properties are discussed and formalized into inference rules. At the end of this paper, this method is proved to be valid.

SVD-based digital watermarking algorithm for 3D mesh models

Qing-Song AI Zu-De ZHOU Quan LIU

2007, (12): 2931-2933.

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A new watermarking scheme for the copyright protection of 3D mesh models was proposed. In this scheme, the geometric signal processing theory was adopted to transform 3D mesh signals into planar regularly sampling signals, and then Singular Value Decomposition (SVD) technique was employed to embed watermark. Experimental results show that the proposed algorithm has better imperceptibility and stronger robustness.

Vector quantization watermarking based on improved ant colony algorithm

2007, (12): 2934-2936.

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A new vector quantization watermarking algorithm was proposed. At first, the error model of the vector quantization, watermarking embedding and the noisy channel were established and further the simplified model was given. Because the watermark embedding and the noisy channel were directly related to the codeword index order in the model, at the same time deciding the codeword index was a NP-hard problem typically, so the ant colony algorithm was introduced to optimize it in order to make the bit error rate lower and the embedded watermark more invisible. The ant colony algorithm is used in the watermarking field and the experiments show that the vector quantization watermarking based on the improved ant colony algorithm is successful.

Color visual multi-secret sharing scheme with dynamic and verifiable threshold

Yanshuo Zhang Zhuojun Liu

2007, (12): 2937-2939.

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A dynamic and verifiable threshold color visual multi-secret sharing scheme was proposed. The scheme shared many secret images so that any t or more sub-secrets could recover the secret image, but any t-1 or fewer of them gained no information about the original secret image. In the scheme, multiple secrets can be shared in one sharing session. The sub-secret of each participant can be used by many times，and the secrets can be renewed without renewing the sub-secrets of the participants. What is more, a participant can be flexibly accepted or fired.

Analysis of Blowfish cryptography

qianchuan Zhong

2007, (12): 2940-2941.

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Since Blowfish algorithm has been proposed and applied widely, a lot of attacks aiming at it have appeared, but none of them has substantial challenge to it. Concerning the weakness of Blowfish algorithm that appeared in the encrypting process, the detailed process was given that the subkey array renewed from Blowfish algorithm could educe a key array K directly, which may result in that the whole Blowfish algorithm was broken in applications. Moreover, slide attack was proved to be not effective to Blowfish algorithm with reduction to absurdity, its precondition was not satisfied.

Group signature on conic curve over Zn and its applications

Biao Wang Hong-gang Lin Song Lin

2007, (12): 2942-2944.

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A group signature scheme was designed on conic curve Cn(a,b) over Zn. It can be applied in system of E-cash issuance. The scheme security is based on difficulties in factorizing large integer and computing discrete logarithm on Abel group (Cn(a,b),). By fetching NAF in calculating the multiples of an element in a group, 1/4 amount of computation was reduced. Compared with classical group signature, the conic analog over Zn has strongly improved the security of computing discrete logarithm. Compared with its counterparts based on elliptic curves over Zn, the conic analog is easier to accomplish, for they not only maintain the existing advantages but also advance with more advantages such as convenient plaintext embedding and speedy operation.

Designated-verifier proxy signature scheme using self-certified public key

2007, (12): 2945-2946.

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As the existing designated-verifier proxy signature schemes are based on the public key systems and ID-based systems, a new designated-verifier proxy signature scheme using self-certified public key was proposed by applying the concept of self-certified public key to the designated-verifier proxy signature. The scheme has the following features: the signing message is unnecessary to transmit, since the designated-verifier can recover it from the proxy signature; the tasks of verifying the authenticity of public key and validating the proxy signature are carried out simultaneously in a single step; no certificate is required for validating the public key. The new scheme is more efficient than the existing ones in terms of communication overheads and computation efforts.

Modeling and quantitative analysis methods for network security management systems' survivability

2007, (12): 2947-2950.

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Modeling and analyzing the survivability of network security management systems is a very important research hotspot, but there is no better solution for the large-scale network modeling and evaluation of survival. The limitation of the existing two methods for network security management systems is showed as the following: the cut-set method cannot analyze large network, and the Monte-Carlo method gives only the interzone evaluation, but not accurate results. A connected path method was proposed to calculate system survivability, in which the mathematics model was used and the program of the arithmetic was given. Then, a further analysis was given to the relations between survivability and power of single path. That will form a good foundation for building a perfect survivability analysis platform in future.

Augment semantics SVO logic-based analysis of two-dimensional authentication protocol

2007, (12): 2951-2953.

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The two-dimensional construction-based entity authentication protocol without transmitting secret key in an insecure channel makes the authentication process safer and more convenient. But the validity and security of the protocol have not been proved strictly. Considering the characteristics of the entity authentication protocol, augment semantics SVO logic was used to describe its rationality and analyze its operation, and a flaw was found. A modification based on the SVO analysis was made to solve the flaw, which made the protocol more validate and more secure.

Design and implementation of improved SSL VPN system based on L2 switching technology

Yan-yuan Zhang

2007, (12): 2954-2956.

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As traditional SSL VPN suffered from insufficient support for applications and weak security, an improved SSL VPN system architecture based on L2 switching technology was put forward. It accommodated three schemes: virtual switch deployed at SSL VPN proxy Server, data encapsulation standards and client firewall. The improved system not only meets all the applications, but also enhances the security of communication tunnels and client. Finally, the delay performance and concurrent performance testing of improved system were given.

Optimization implementation of high speed AES accelerator

2007, (12): 2957-2959.

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A high speed implementation of AES algorithm based on FPGA was presented for Gbps-network-processor encryption requirement. Using T box and grading address coding in memory space and data access, it enhanced the implementation parallelity, and then the speed of AES coding was increased significantly. The entire AES algorithm was implemented on a Xilinx XC2V2000 Virtex2 FPGA. The maximum frequency of 179.6MHz and maximum throughput of 22.99Gbps were achieved.

Proxy blind signature without using Hash and Redundancy functions

Cheng－Gang QIU Fang-wei Li

2007, (12): 2960-2961.

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In Cryptography, the scheme of signature using Hash and Redundancy functions will be faced with related attacks. Therefore it will result in lower security. So a proxy blind signature scheme without using Hash and Redundancy Functions was proposed, whose security equaled to the difficulty of the discrete logarithm problem. And it avoided the insecurity of the related function. Analysis shows that this scheme has really completed unforgeability and unlinkability in the electronic tractions of business, and prevents the repudiation efficiently. Meantime, the new scheme reduces the computational load for exponentiation, avoids the computation for Hash function and improves the signing speed.

Mixed coordinate for point algorithms on elliptic curve over GF(2m)

Xian-Wen YANG Zheng Li

2007, (12): 2962-2964.

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Elliptic Curve Cryptosystem (ECC) is a kind of public-key cryptosystem based on algebraic curve. Point algorithms on elliptic curve are essential operations in ECC and its speed are decided by selected coordinate. On the basis of analyzing existing coordinates such as affine coordinate, Standard projective coordinate, Jacobian projective coordinate and Lopez & Dahab projective coordinate, an extension of Lopez & Dahab projective coordinate was proposed and a mixed projective coordinate was given to improve the speed of scalar multiplication. The result of analysis indicates that the operation time complexity of scalar multiplication under the mixed projective coordinate is more reduced than under any other coordinates.

Communication-efficient key agreement protocol in Ad Hoc networks

Jing LI YUE-Wei DING

2007, (12): 2965-2968.

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A secure communication-efficient key agreement protocol based on the bilinear pairings in Ad Hoc networks was proposed. In this protocol, the dynamicity of the networks was considered and the 1-hop assumption was weakened by employing hierarchical routing techniques to ensure that the logical model of key agreement consists with the actual topology of networks. As a result, the communication overhead was reduced. The analysis result shows that the proposed scheme is applicable to Ad Hoc networks with large size.

Application of Markov model in real-time evaluation of VoIP speech quality

Wei Wang Zhensong Wang

2007, (12): 2969-2972.

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To accurately calculate the Ie-eff coefficient when evaluating VoIP speech quality with the ITU-T G.107 E-model, a real-time evaluation algorithm based on Markov model was presented. Through the establishment of 3-state Markov model for Ppl and 2-state Markov model for BurstR, formulas were derived and corresponding statistics algorithm was given. Commercial test results indicate that this algorithm can accurately evaluate the VoIP speech quality in real-time environment.

Services selection based on commodity-market in grid workflow

Wan-Cheng NI Lian-Chen LIU Cheng Wu

2007, (12): 2973-2975.

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Services selection is important in Grid workflow. To deal with the inefficient resources utilization brought by greedy competition for QoS in current Web services composition methods, an "on-demand" Grid services selection method based on commodity market was put forward. Based on global evaluation model for Grid workflow, services selection was modeled as a 0-1 multi-dimensional knapsack problem by transforming the service requester's requirements into constraints. Furthermore, the selection model was improved with economic "price-demand relationship". Finally, experiments show that the proposed services selection method can bring load balance, which is helpful to the utilization of Grid resources.

Network traffic prediction based on combination method

Yuan LIU Xiao-Hang LI Yuan-Zhen LIU

2007, (12): 2976-2978.

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After summarizing the existing traffic prediction methods, a combination method of network traffic prediction based on a variety of forecasting techniques was proposed. According to the theory of decomposition and reconstruction based on multi-scale of wavelet, the network traffic was decomposed into approximation signals and detailed signals of different scales. Then these signals were reconstructed into several low frequency and high frequency time serials by wavelet. These serials were predicted by Linear Minimum Mean Square Error (LMMSE) and Auto Regressive (AR) models respectively according to their different features, and the predicted results of all serials were combined into the final prediction traffic. Simulation results with the real traffic traces show that the method can more accurately predict the future of the network traffic.

Distributed cluster heads selection algorithm based on average energy consumption of nodes in WSN

2007, (12): 2979-2981.

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In the cluster-based routing protocols, it depends on the reasonable selection of cluster heads to prolong the life cycle of the sensor networks. A new distributed algorithm for cluster heads selection based on the average energy consumption of sensor nodes in each period was proposed, which was an improvement of the LEACH algorithm. When selecting cluster heads, the new algorithm considered not only the problem that sensor nodes shall become cluster heads in turn, but also the average energy consumption of nodes in each clustering and working period. Simulation results show that the new algorithm, compared with LEACH and DCHS, can reduce energy consumption of the whole network and balance energy consumption level of the whole network, thus further prolong the life cycle of sensor networks.

Time synchronization algorithm with synchronization precision stability for multi-hop wireless sensor networks

Shi-Jun WANG Chao-Nong XU Yong-Jun XU Dou NIU

2007, (12): 2982-2985.

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The synchronization precision stability in time synchronization algorithm for wireless sensor networks was studied, and the factors that had impact on the multi-hop synchronization precision for OTSP algorithm were given. Then, a new synchronization precision stability time synchronization algorithm was presented. This algorithm estimated the crystal frequency deviation of different nodes, and each node in multi-hop networks was synchronized with the benchmark node. Experiment proves that the proposed algorithm is much better than OTSP algorithm in term of synchronous precision stability.

Study on network traffic forecast based on improved wavelet neural network

Jian YU

2007, (12): 2986-2988.

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The time series of network traffic data was modeled and forecasted based on Wavelet Neural Network (WNN). The limitation of the conventional training algorithm of WNN was introduced and Adaptive Quantum-Behaved Particle Swarm Optimization (AQPSO) algorithm was proposed to train WNN. The parameters of WNN were optimized and the forecast model of WNN based on AQPSO algorithm was built. The experimental results prove that the model is efficient in network traffic prediction with good astringency and stability.

Real-time aware on-demand distance vector protocol in Ad Hoc

2007, (12): 2989-2991.

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Most of the existing Ad Hoc routing protocols have the disadvantage of high delay and can not satisfy the transmission requirements of real-time applications. Based on the Ad Hoc On-demand Distance Vector Routing (AODV) protocol, a real-time aware Ad Hoc on-demand distance vector routing protocol named RAODV was proposed. The performances of RAODV and AODV under different network conditions were compared by simulation experiments. The results of the experiments show that RAODV can obtain as good packet delivery fraction as AODV, but has lower average end-to-end delay of data packets and routing load than AODV under normal network load condition. Under high network load condition, the performances of both protocols declined. However, the performance of RAODV declined much less than that of AODV. At the same time, RAODV has higher packet delivery fraction, and lower average end-to-end delay of data packets and routing load than AODV.

Study on fairness for core-stateless fair queuing algorithm

2007, (12): 2992-2994.

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The Core-Stateless Fair Queuing (CSFQ) algorithm is a routing mechanism designed to achieve fair bandwidth allocation. A new algorithm named MCSFQ based on CSFQ was proposed to achieve the approximate fairness. According to the variety of a queue's length, the new algorithm adjusted the link fair share rate to take its value more reasonable as congestion. Simulation results show that the new algorithm achieves comparable or even better bandwidth fairness between different data flows.

Design of real-time network topology discovery system based on OSPF and BGP

Wen-xi PAN

2007, (12): 2995-2997.

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A real-time topology discovery technique based on Open Shortest Path First （OSPF） protocol and Border Gateway Protocol (BGP) was put forward to solve the difficulties in multi AS topology discovering. The system gathered the BGP message that transfer within AS, and the OSPF message that transfer in AS. Through analyzing these messages, system can describe the state and change of multi AS topology rapidly, accurately and efficiently. Technologies of message gathering, message analyzing and topology graphics saving were discussed.

TOA estimation of UWB based on PCA

Chun-Ling Tang Guo-Qiang Xiao Ming-Gang Sun

2007, (12): 2998-3000.

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An algorithm based on PCA（Principal Component Analysis） was presented for estimation of signal arrival time in UWB system. This algorithm analyzed the signal eigenvectors of the correlation matrix for the received signal associated with noise components, and then the received signal was projected to every signal eigenvector to get the sum of the projections. Selecting a threshold with low complexity and sampling rate, estimate precision between Multiscale Energy Products (MEP) and the proposed method was compared. Simulation results show that the probability of estimated mean absolute error which is less than 12cm exceeds 90% in the proposed method and that of MEP is lower than 45%.

Semantic P2P protocol based on ants search algorithm

2007, (12): 3001-3003.

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Because the operating mechanism of living organism have been extensively used to improve the performance of distributed system, the semantic similarity was introduced into the P2P protocol based on ants search algorithm and some researches on the mechanism of retrieving resource, updating pheromone, treating with the changes on the network were done. In the simulation experiments, the performances of new protocol and k-random ways protocol were compared and the results show that semantic P2P protocol based on ants search algorithm can not only increase the efficiency of searching keywords but also decrease the load of P2P network.

Time-slot Scheduling Algorithm Based on Weighted Traffic Load in Wireless Sensor Networks

yanping wu ming liu juan ye

2007, (12): 3004-3006.

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An energy-efficient adaptive time-slot scheduling algorithm（EATA）based on clustering for MAC protocol of wireless sensor networks was described. In this algorithm, the cluster head adjusts the time-slot of nodes according to their weighted traffic load in a proper order and frequency, thus the idle listening was reduced, and the energy consumption balancing among nodes was achieved with a low latency. Simulation results show that the algorithm EATA improves the network energy usability and increases networks lifetime.

Optimization of delay in network time synchronization algorithm

2007, (12): 3007-3008.

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In order to improve measured precision of time delay in Network Time Protocol (NTP), a highly precise time synchronization method was proposed in network. The method adopted the self-discarding packet technique that was a means of determining transfer by comparing the queue length of the transiting router with a specified queue value on the packet. Simulation results show that this method has a very good feasibility.

Text feature word selection based on relationship between words

2007, (12): 3009-3012.

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The description of text feature is one of the fundamental works of Natural Language Processing (NLP). Some scholars often use the Vector Space Model (VSM) in description of text feature at present. VSM adopts statistical or experiential term weighting algorithm, term weight in each dimension of the text feature is its TF-IDF value. But TF-IDF is unable to emphasize the significance of key terms which contribute mainly to the content of a text. TF-IDF does not consider the relationship between words and is important in information extraction. In allusion to the disadvantage mentioned above, a new feature selection and term weighting approach based on keywords and word co-occurrence was proposed. Based on TF-IDF, the structure information and mutual information were employed to extract key words of the text; and word location, word dependence, word frequency, document frequency, and relationship between words in weighting a term were integrated. In SVM classification experiment, the approach outperforms the traditional TF-IDF approach with a boost in average precision.

Merging term similarity and term correlativity in retrieval models

Jian－min XU Song ZHU Fu-jie CHEN

2007, (12): 3013-3015.

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How to improve the retrieval efficiency by means of term relationships was discussed. In order to integrate the specialties of term similarity and term correlativity, a new method to mine the term relationships was proposed. In this method, a correction factor from term correlativity to term similarity was used to adjust the level of relations with the term, which is a more accurate solution to the concept of the terms of semantic matching problem. Applying the new method to two retrieval models, experimental results show that the retrieval efficiency can be improved more obviously.

Community mining with heterogeneous relation

WANG Jin-Long Xu congfu

2007, (12): 3016-3018.

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The problem of mining hidden communities on heterogeneous social networks was investigated. On the basis of the bibliographical data, this issue solved community mining problem in heterogeneous relation, and extracted the relation chain. Therefore, it can help researchers do some research work.

Extraction of Chinese term based on Chi-square test

Wen－min HU Ting-ting HE Yong ZHANG

2007, (12): 3019-3020.

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Discovering the term has very important applications in Chinese information processing and language learning. A method for the extraction of Chinese term based on Chi-square test was proposed. First, download Web documents and build a corpus, then prime words were extracted by using the F-MI parameter improved by mutual-information，while combined words were extracted by the Chi-square test with the help of decomposition of prime string. The experiments show that the algorithm can effectively improve the precision in the extraction of Chinese term.

Improved query algorithm based on twig pattern for XML database

李素清陶世群

2007, (12): 3021-3025.

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XML has become a standard for data exchange over the Internet. Many query methods about XML document have been presented. An improved TwigStack algorithm for twig pattern of XML query was proposed. The algorithm utilized the idea of PathStack algorithm in its main algorithm to achieve twig pattern query. Compared with only using PathStack algorithm, the ITwigStack algorithm will not produce intermediate result during running process, but enhance query efficiency after finding the root of twig pattern.

Algorithm based on perceptron for biomedical

Jun-Feng HU

2007, (12): 3026-3028.

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Biomedical Named Entity Recognition (Bio-NER) is a basal work for mining and utilizing biomedical literatures in bioinformatics field. Currently, the efficiency of Bio-NER is low because of the difficulty of biomedical named entity boundary identification, so an algorithm based on perceptron for biomedical named entity boundary identification was put forward. The algorithm identified the boundary of biomedical named entities based on token filter, n-gram and biomedical named entities filter, trained the weights with stochastic gradient descent. The experimental results obtained on GENIA corpus 3.02 show that the precision and recall of the algorithm are around 71.5% and 79.2% respectively, higher than the results of the related works. Moreover, the algorithm is relatively simpler and faster, so it can be easily applied into practice.

Improved cascade AdaBoost classifier

Feng Liu

2007, (12): 3029-3031.

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Assistant discriminant function was used to help decision by the classifier in the cascade architecture. The samples which were rejected by the AdaBoost classifier would transfer to the assistant discriminant function and the assistant decision would be made. Result of current AdaBoost classifier and history discriminant information has been taken into consideration in the assistant discriminant function. The experimental results show the improvement of the recognition performance comparing to the cascade AdaBoost classifier and 2D cascaded AdaBoost classifier.

Associative classification algorithm based on support and confident thresholds tuning technique

Jian Zhang

2007, (12): 3032-3034.

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The set of the support and confident thresholds usually affects the accuracy of classification based on association rules. As for the previous associative classification algorithms, the two thresholds are always set by experiences, so it is difficult to ensure that the classifier can always get the best accuracy. In order to solve this problem, the optimization strategies can be introduced to associative classification algorithm. The hill climbing search method was used to improve the Apriori_TFP_CMAR algorithm to get the highest classification accuracy of the set of support and confidence thresholds. This strategy can avoid the unreasonable set of threshold, and enhance the classification accuracy.

Design and realization of MDX compiler

2007, (12): 3035-3038.

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The design and realization of Multi-Dimensional eXpression (MDX) compiler for Online Analytical Processing (OLAP) database was discussed. The Lex and Yacc based road map for designing the MDX complier which parsed the MDX query into a query tree object was studied. Lexical analysis, syntactic analysis and semantic processing were carried out along with the access to metadata and role based access control. The MDX compiler not only checked the syntax and semantics, but also authenticated and authorized users to achieve information security.

Community mining based on email classification

2007, (12): 3039-3041.

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Concerning the requirement of the massive e-mail data processing and the practical operation demand, an e-mail mining system based on three-layer filtering model was designed. It filtered the massive e-mail data through analyzing the time attribute, the text information and the address of the e-mails level by level, which reduced the search scope in extent and increased the mining strength in depth. Starting with the sensitive information of text and subject, the system classified the email data automatically, and then constructed an E-mail Social Network (ESN) according to the address information to reveal the community structure hidden in the e-mail data. Finally the effectiveness was validated through the experiment.

Fast K-means algorithm based on influence factors

MingWei Leng Xiaoyun Chen

2007, (12): 3042-3044.

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The running time of K-means overly depends on the initial points but the right value of k is unknown and selecting the initial points effectively is also difficult. To solve this problem, depending on the research about initialization deeply, a high effective approach used to select the initial points was presented, which ensured at least one point to be selected in each cluster. Influence factor between clusters was presented to measure the similarity of two clusters, and a new merging algorithm based on it was put forward. This algorithm and the initial points' selection algorithm can automatically and fast give the actual value of k and select the right initial points based on the dataset characters. Finally, Gaussian datasets were used to test the algorithm and a satisfying result was obtained.

Geometric rectification for camera-captured document images

Xue-dong TIAN Xing-Jie Ma

2007, (12): 3045-3047.

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The document images filmed by digital devices such as digital cameras are always coupled with distortions, which will result in a failure of the layout analysis, segmentation and recognition. In order to enable ordinary recognition software to recognize the digital document images, it is necessary to carry out their geometric rectification. A new identification technique was proposed to distinguish three types of image distortions and then the restoration of camera images was carried out respectively. Experimental results show that the proposed classification method and restoration techniques are effective.

New rate control algorithm in MB layer

2007, (12): 3048-3050.

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The fact that the mean square of AC coefficients in DCT is equal to the variance of pixels was employed to represent the motion complexity of macroblock (MB). Based on this, the new rate distortion model was integrated into the existing rate control scheme of H.264. The simulation results show that the proposed scheme can more effectively control the rate variant, and improve PSNR gain as well.

Codebook design of image vector quantization based on particle swarm optimization

Xu-Bing ZHANG Ze-Qun GUAN Jimg-Zhong XU

2007, (12): 3051-3054.

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The LBG algorithm depends upon the initial codebook and is prone to converge to a local optimal solution. To solve this problem, Particle Swarm Optimization (PSO) was adopted to design the optimal codebook of image Vector Quantization (VQ) and PSO Vector Quantization (PSO-VQ) algorithm was presented. According to PSO-VQ, a particle indicated a codebook, and the optimal codebook was obtained from iterations of the initial codebooks by method of the particle evolvement. To ensure the solution converge to the global optimal codebook, the Particle Coherent Operation (PCO) was also proposed, by which the code vectors of each initial codebook were sorted in ascending order based on the gray mean, and so that the inner structures of all the particles were essentially identical. The experimental results show that the PSO-VQ algorithm is better than LBG in terms of the PSNR and subjective effect of the decoded image. Meanwhile, it extends the application of the PSO.

4×4 intra prediction mode selection algorithm in H.264/AVC

Yuan-Yuan Ding Yu-Juan Si

2007, (12): 3055-3057.

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Based on the analysis of intra-prediction technology, a fast 4×4 intra-prediction mode selection algorithm was proposed. The comparability between the current 4×4 block and the spatial/temporal 4×4 block was computed, and whether to skip the process of mode decision was decided. For other 4×4 blocks, some less probable modes were eliminated based on Sum of Absolute Transformed Difference (SATD) and temporal/spatial correlation. Experimental results show that compared to JM10.2, for IIII structure: timesaving is 44.07%; for IPPP structure: timesaving is 20.49%. The bit rate and Signal to Noise Ratio of Y (SNRY) are almost invariable.

Middle-view based FGS scalable scheme for multi-view stereo video

Xiao-Wei SONG Lei YANG

2007, (12): 3058-3061.

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Based on MPEG-4 FGS technology, a new scalable coding algorithm for multi-view stereo video was proposed, combining FGS scalability with views scalability. In the proposed algorithm, the middle-view sequence was coded as a base layer and a FGS enhancement layer, with other view sequences all predicted from the middle-view sequence yielding each view's FGS enhancement layers. In this coding structure, three cases (I, P, B frames) were considered, and the corresponding improvements had been implemented. The new method can provide a flexible scalability performance, and it can match many different kinds of transmission requirements. Experimental results proved the multi-view scalability performance of the proposed scheme.

Candidate weight method for reassembling BMP image fragments

dong-ping wang Qingxian WANG

2007, (12): 3062-3065.

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According to the special requirements of computer forensics, a process model was presented to extract the file fragment and reassemble them for digital forensics, and the reassembly of image fragments was also described. Three different methods were proposed based on a k-vertex disjoint graph technique which was applied to the reassembly of image fragments: Similar Coefficient Matching (SCM), Volatility Gradient Matching (VGM) and Prediction Pixel Matching (PPM), to evaluate the candidate weights between any fragments. Extensive experiments show that the highest accuracies of evaluating weights are correspondingly 93.90% and 87.27% about color images and grayscale images, which improves the precision and the efficiency of the image reassembly.

Non-self-overlapping structured grid generation by Gregory method

Ichiro Hagiwara

2007, (12): 3066-3068.

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A method about generating non-self-overlapping and smoothing grid on N-sided trimmed parametric surface was proposed. The region was firstly partitioned into N number of four-sided sub-domains by using Gregory method. Meshes were generated in each four sided patch. Then mapping was used to achieve grids in three dimensions. To eliminate self-overlapping grids during mapping, an optimization function was set on the characteristics of self-overlapping and structured grids. By a conjugate gradient method, the optimized numeric solution was obtained to construct non-self-overlapping grids on n-sided surface. The presented method can be used to generate non-self-overlapping and smoothing meshes in n-sided surface domain. Therefore, the application of the trimmed surface is enlarged.

Fast mode decision used in video surveillance system

2007, (12): 3069-3071.

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In view of the high complexity of current mode decisions, with the analysis of video sequences mode decisions in the video surveillance system, the characteristic that a lot of SKIP modes and 16×16 modes was used in the frames of video surveillance was summed up. Then a SKIP mode plus 16×16 mode prediction algorithm was presented. In addition, to solve the problem of too many candidate modes in coding moving macroblock, a method of some modes pre-exclude was proposed considering the low unilization ratio of some modes in the video surveillance system. The experimental results show that there is about 84% encoding time saved compared with the original H.264 reference software for the video surveillance sequences with almost no loss of video quality, and the proposed mode decisions are more suitable for video surveillance compared with Yury V'54%.

AdaBoost evolutionary algorithm based on template match

Jia-Hui CHEN Zhong-Liang FU La-Mei CHEN

2007, (12): 3072-3074.

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An evolutionary algorithm of AdaBoost based on template match was proposed. The algorithm used weighted templates to structure each weak learning classifier, which overcame the shortcoming of structuring classifier by using a single feature. Experiments show that the proposed algorithm can not only obtain high recognition accuracy for printing character and some kinds of handwritten digits, but also enormously shorten the training time when structuring classifiers. The evolutionary algorithm is stable and effective.

Improved texture simulation method

Wan-Ning DING Yao-lin GU

2007, (12): 3075-3077.

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A new multiscale fluid model based on Navier-Stokes equation and viscous fluid equations was proposed. It improved the solution of the mass conservation equation and the method of the dispersed equation through introducing a new method of vorticity confinement. Meanwhile, it could simulate real-time fluid flow and average the vectors. The method could also be applied to the texture. The test results show that this method can improve the real-time fluid simulation speed and the similarity with the same amount of time.

Application of fuzzy edge detection to watermark blurring detection

Jing-Shuang Wang Chen-Bin Chen

2007, (12): 3078-3080.

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The blurring of security watermark is one of the important indicators in the quality inspection system of security printing. In order to ensure the accuracy and the real-time property of quality inspection, an algorithm to measure the blurring of security watermark was proposed. First, a modified fast fuzzy edge detection algorithm was used to detect the contours of watermark images. Then the changes of marginal gray were obtained by calculating the gradients of marginal pixels. Finally an evaluation function to detect the quality of watermarks was designed. Experiments approve that the algorithm is faster and more accurate, and has a good application prospect.

Gait recognition research based on region variance feature and SVM

Ming-Cong FENG Ge Hong-wei

2007, (12): 3081-3083.

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According to the different feature between body and gait variance, a new gait recognition approach based on region variance feature was presented. First, the background subtraction was used to extract body silhouette. Then the dimensional silhouette was divided into several regions and feature vectors were acquired. Finally, gait classification and recognition were performed by support vector machine. The method was applied to two data-sets (UCSD and CASIA). Experimental results demonstrate that not only can the approach overcome the information lost that results from a few feature vectors but also get satisfying recognition performance.

Study of handwritten Chinese characters multi-classification recognition based on structure features of characters

Jian-ping WANG Xiao-Xue WANG

2007, (12): 3084-3088.

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A multimode recognizing method for two-type mode discrimination was presented based on the structure and complexity degree of Chinese characters. The type code and decomposing arithmetic of Chinese character structure were given. Character components were judged by complexity. Moreover, based on component complexity apiece, appropriate character-pick-up methods were selected to implement handwritten Chinese-character multimode recognizing methods fusion on character structure decomposer. Similar characters were judged by two stages classification to improve the recognition efficiency. The method was proved in effect by emulation test.

Two-phase framework of program model checking

2007, (12): 3089-3091.

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Model checking is an important method of verifying logic properties of finite state systems, and also a supplement to the shortage of software testing. Flow analysis and language transform are two main methods for program model checking, but both are limited in practice. Based on the analysis of shortages and strong points of two program model checking methods, a two-phase program model checking framework was proposed, which can efficiently improve the applicability of checking large programs with the framework by integrating two methods of program model checking.

Web application development approach supporting multi-target-frameworks

GuoDong Huang

2007, (12): 3092-3094.

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Platform specific models in most MDA-based development approach for Web applications are defined as the concrete framework on which the target system runs, which leads to the close coupling between platform specific design models and the target frameworks as well as reduce the design model's reusability. In order to resolve these problems, the description of the target framework for Web application was added in the extended MDA-based development model that supported multi-target-frameworks, and in which abstract platform specific model and concrete platform specific model was introduced. J2EE and JavaServer Faces were respectively used as target platform and target framework in the experimental research. The experimental results show this approach can make an effect support to model-driven development for the enhancement of the model's flexibility and reusability.

Rule-based scheduling method for sensors on early warning satellites basing on task analysis

2007, (12): 3095-3098.

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The scheduling method of sensors on early warning satellites was studied. Firstly, characteristics of missile warning tasks were analyzed, and a task compositing method was designed to simplify relationships between tasks and sensors as well as to reduce resource occupancy of one task. Secondly, a scheduling framework based on periods and events was presented to handle dynamic tasks. Thirdly, a rule-based scheduling method was given, which paid more attention to scheduling speed than to performance of the outcome and consequently met with systemic requirement on timeliness. The result of an emulation shows that satisfying scheduling schemes can be attained during a fixed short period.

Research on restraining bullwhip effect based on demand forecast

2007, (12): 3099-3101.

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Bullwhip effect in the supply chain was studied, and a dynamic model was presented based on exponential smoothing, moving average and demand signal processing. The dynamic model uses demand forecasting method to restrain the bullwhip effect. How the model reduced the bullwhip effect was analyzed. Effect of the three methods was verified by Bode diagram.

Improvement and optimization of embedded file system based on NAND Flash

Chun-lin YANG Hang LEI

2007, (12): 3102-3104.

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At present, the embedded flash file systems specially designed for NAND Flash mainly have two disadvantages: too long booting time and insufficient consideration for wear leveling. According to these two aspects, a new NAND flash file system named SFFS was proposed, which shortened the booting time through changing the management of data nodes and storing the controlling information and data information separately，and made wear leveling better through using a block to store hot data and cold data alternatively.

Traffic incidents detection based on Boosting method and RBF neural network

2007, (12): 3105-3107.

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A new method was proposed for traffic incidents detection based on Boosting RBF neural network. The improved Boosting adopted a new method to acquire parameters, and the weighted parameters of weak classifiers were determined not only by the error rates, but also by their abilities to recognize the positive samples. The features of flow and occupancy rate were extracted from traffic incidents. Then RBF neural network was used to classify the traffic incidents. In order to improve the precision of the RBF neural network for traffic incidents detection, Boosting algorithm was used to build an integration-neural network. Finally a simulation using Matlab was carried out, and the results show that this algorithm can detect incidents rapidly by using a few samples.

Real-time scheduling of periodic messages for MVB

2007, (12): 3108-3111.

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Transmission of periodic messages processing in Multifunction Vehicle Bus（MVB）network should be highly in compliance with the time constraints of the communication. Generally, the bus administrator of MVB utilizes real-time schedule table to manage the scheduling of periodic traffic. On analyzing the scheduling principles of periodic traffic on field bus, the approach how to build the real-time schedule table for MVB with adopting synchronous RM algorithm was introduced. Furthermore, the approach to schedulability analysis based on task response time was proposed, and a new algorithm used to judge the validity of schedule table was also put forward by analyzing the worst case response time. Finally, the application of real-time scheduling algorithm and related way of schedulability analysis were expounded by the example of MVB periodic traffic, which provided some useful guidance for the MVB application.

Lateral control model of intelligent vehicle based on hierarchical fuzzy control

2007, (12): 3112-3115.

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The lateral control of intelligent vehicle is a critical technology of autonomous navigation in Intelligent Transport Systems (ITS). A dynamic target position concept was proposed for more truly reproducing the feature of lane-change on the basis of former outcomes, and a hierarchical fuzzy controller was designed, which can reduce the number of rules in a (standard) fuzzy controller and realize the purpose of real-time control. Additionally, in the lateral control of vehicle, cubic spline curves were employed as alternative paths for lane-changing so that the intelligent control of vehicle lateral movement can be implemented flexibly. The simulation results show that the controlled vehicle change lane smoothly from one to another along with a virtual path, so the fuzzy inference system could simulate well lateral movement characteristic of vehicle in an actual traffic situation.

New intelligent map-matching algorithm

2007, (12): 3116-3118.

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To overcome the disadvantage of inadequate information in map-matching algorithm for using current positioning point only, an intelligent map-matching algorithm was proposed by utilizing both current positioning point and some history positioning points. In this algorithm, an average Fréchet distance was employed to define the distance between two history positioning trajectories. Additionally, a credibility, P, as an evaluation index was generated by cloud controller so that the proposed algorithm could provide not only warning information to user when mismatching occurred, but also a means of fast recovery from failure. The simulation test demonstrates that the precision and accuracy of the proposed algorithm is superior to that of matching algorithm only using the current positioning point.

Lower power test scheme based on folding test set

2007, (12): 3119-3121.

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A full deterministic low power test scheme based on the feature of folding counter was presented. Firstly, several folding test sets were used to detect most of the potential faults and then the data in scan cells was inverted to generate the test patterns for the other faults. An address counter and Random Access Scan (RAS) were combined to implement a parallel folding controller. Compared with the traditional mixed mode test, the test power caused by pseudo-random test patterns was decreased. Experimental result shows that the total test power and test time can be greatly reduced.

Study on critical path algorithm in multi-stage service model

2007, (12): 3122-3125.

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Concerning the characteristics of multi-stage service model, the method of building the corresponding workflow model for the multi-stage service model was introduced. An improved critical path algorithm, which added support to common structures in a workflow model, was discussed. In this algorithm, the workflow model was viewed as an M/M/n limited waiting queue network and the request arrival rate and execution time duration of activities in various common structures were discussed. Through this algorithm, the path with the longest average execution time could be calculated and this provided a basis for system performance optimization.

Dynamic energy-efficiency algorithm for soft real-time multiprocessor system

Xia Liu JIA Zhi-ping

2007, (12): 3126-3128.

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Combined with Dynamic Voltage Scaling (DVS) and (m,k)-firm model, a completion ratio guaranteed dynamic energy efficiency algorithm named VAP_DY for the execution of dependent tasks on soft real-time multiprocessor systems with multiple supply voltages was proposed. VAP_DY leveraged application's performance requirements, uncertainties in execution time, and tolerance for reasonable execution failures to scale each processor's supply voltage at run-time to reduce multiprocessor system's total energy consumption. Analyses and experiments show that VAP_DY can effectively reduce energy consumption, while guaranteeing both timing constraint and completion ratio.

Test data compression technique based on dimidiate partition

Nian Zhang Hua-guo Liang Mao-xiang Yi

2007, (12): 3129-3131.

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A new test data compression scheme was proposed, which can reduce the test data volume effectively. Firstly, the whole test set was partitioned to several length-fixed blocks. For non-0/1 data block it used dimidiation technique, and for 0/1 data block it used some mark-bits to represent the times of partitioning. Compared with the traditional data-coding methods, the proposed scheme only needs to know the times of partitioning to express the data length. At the same time, the proposed scheme uses simpler circuit structure and communication protocol to decompress the coded test data.

Research and realization on fast collision detection algorithm in virtual assembly

Li-Li ZHU Yi ZHUANG Yan-Feng YE Chun-Run GAN

2007, (12): 3132-3135.

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Concerning the special requirements of collision detection in the virtual assembly environment, a virtual assembly-oriented two-layer exact collision detection algorithm named HSDHBB was proposed based on bounding volume boxes and space division method. The algorithm firstly usd space decomposition method to identify potential regional intersection and then used bounding volume boxes to locate the intersection triangles and the exact points. Methods of constructing the bounding volume boxes tree and space division were given, and the data structure of Hash table was used to accelerate the collision detection in space division. Finally, the algorithm was applied in CATIA, the results show that the algorithm can effectively meet the real-time and accuracy requirements of the virtual assembly environment.

Test data compression and decompression based on group-frequency Golomb coding

Yi-Qun YE Hua-guo Liang Shen-Cai ZHU Nian ZHANG Kai-Hua ZHAN

2007, (12): 3136-3138.

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A test data compression method called group-frequency Golomb coding was presented. Regarding the nonuniformity of the run length in the test set, the prefix codes of Golomb were rebuilt, and the shorter codes were used to code the groups that contain more run lengths. In the difference procedure, the don't care bits were evaluated with reason to reduce the number of 1 in the test set, so that the run lengths was reduced. Experimental results indicate that the proposed method can improve the compression ratio of Golomb codes efficiently.

Research on task scheduling in concurrent product development

Xian-Sheng QIN

2007, (12): 3139-3141.

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The task decomposition method in concurrent product development was proposed, which can reduce the complexity of the task and increase independency of the task effectively. Then, the task scheduling problem in resource restriction was analyzed. The task scheduling strategy that weighed importance rate and delay rate of the task as the priority was provided. At last, the calculated example was given.

Application of neural network based on ant colony algorithm in credit rating

Zheng-jiang WANG Bin LEI

2007, (12): 3142-3144.

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Back Propagation (BP) is widely used in credit rating, but it has such shortcomings as slow convergent speed and easy convergence to the local minimum points. A credit rating model that combined ant colony algorithm with neural network was proposed. It not only has the extensive mapping ability of neural network, but also has the advantages of high efficiency, rapid global convergence and distributed computation of ant system. The experimental result indicates good performance can be obtained by neural network based on ant colony algorithm in application of the credit rating.

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