Table of Content

01 January 2008, Volume 28 Issue 1

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Network and communications

AOA location algorithm based on RBF neural network

2008, 28(1):  1-3,6. 

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Due to the application of smart array antenna, it is possible for serving base station (BS) to deliver accurate angle of arrival (AOA) measurement of mobile station (MS) radio wave，it can be used to calculate the position of MS. In order to mitigate the effect of Non-Line-Of-Sight (NLOS ) propagation, Based on geometrically based single-bounced(GBSB) statistical model , an AOA location algorithm based on the RBF neural network is proposed. The fast study and non-linear approach capacity of the neural network is made use of to correct the error of NLOS propagation, Then position is calculated by least-square (LS)’s algorithm to improve location accuracy. The simulation results indicate that the location accuracy is significantly improved and the performance of this algorithm is better than that of LS’s algorithm in NLOS environment.

Hierarchy-based resource discovery algorithm in grid environment

2008, 28(1):  4-6. 

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In order to solve the problems of conventional resource discovery framework, a hierarchy-based model was discussed, which combined super-peer model and contact node, a membership join protocol was introduced, and a resource discovery algorithm was proposed based on Time To Live (TTL) limit and cache list. The network framework with good scalability can adapt to complexity and heterogeneity of grid resources. The simulation shows that the algorithm works well, query time is minimized and efficiency of resource discovery is improved in grid environment.

Routing algorithm based on ant colony optimization

Wang He-yi Ding Jian-Li Tang Wan-sheng

2008, 28(1):  7-8,13. 

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This paper presents an approach bases on ant colony optimization route algorithm of mobile Ad Hoc networks. It can effectively bear network load in Ad Hoc networks by using the self-adaptability of that ant colony algorithm. The simulations in NS-2 show that it performs very well on Ad Hoc environments, especially in throughput, average latency, and delivery ratio. The performance is better than that of Ad Hoc On-demand Distance Vector routing (AODV) and Dynamic Source Routing (DSR).

Fast algorithm for data frame synchronization in radio data system

Gang Wu Xu-tao Lv Song Wang

2008, 28(1):  9-10,1. 

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After the first switched on or after a prolonged signal-fade, the receiver of Radio Data System (RDS) must achieve synchronization quickly. The standard algorithm, which calculates the product (modulo-two) of the received binary sequence multiplied by the parity-check matrix to check whether the receiver has achieved synchronization, is very slow. A data frame synchronous fast algorithm based on look-up table was proposed in this paper. The standard algorithm was simplified into the problem of solving three bytes remainder for the received binary sequence. Whether the receiver is synchronized can be determined by checking the remainder table. The fast algorithm improved the operating speed and reduced the demanding memory space. Simulation result indicated the validity and efficiency of the proposed algorithm.

Demand-based spectrum allocation algorithm in multi-cells cognitive radio network

Jie Chen Chu-lin LIAO Shao-qian LI

2008, 28(1):  14-16. 

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A demand-based spectrum allocation algorithm between cognitive radio cells was proposed. Based on the combination of graph coloring model and the concept of spectrum quality grading, the proposed algorithm allocated the available spectrum to cognitive radio cells to meet demand maximally under QoS guarantee. Simulation results show that, compared with the original algorithm, the proposed algorithm can better satisfy demand in the network.

Distance estimating algorithm in WSN based on minimum hop routing

Ming-Cai Zheng Da-Fang Zhang Cheng-Xue Zhu

2008, 28(1):  17-20. 

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Indirect distance measuring is a way with high performance vs. price ratio, but more work should be done to improve the measuring precision. Derived from the behavior characteristics of the wireless sensor networks based on minimum hop count routing, a distance estimating algorithm based on the minimum hop count and the routing redundancies was presented. Compared with the DV-hop algorithm, the measuring precision is improved largely by use of the routing redundancies. The analysis and simulation validate that the method is quite effective in the wireless sensor networks deployed with dense nodes.

Small-world-based energy-efficient query strategy for sensor networks

Zhi-Qiang LIU Ze-Jun JIANG Li-Fang WANG Jun-Ji WANG

2008, 28(1):  21-24,5. 

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Query processing is one of the most important technologies in sensor networks. To reduce energy consumption of query, a small world based query strategy named Contact-Assisted poweR-efficient Direction-sense-achieved query strategy for Sensor Networks （CardSN） was presented. In CardSN, Contacts act as shortcuts to bring down the average path length of the network; a distributed relative localization algorithm was introduced to achieve a sense of direction. Experimental results show that CardSN has good scalability and can save more energy than ZRP and CAPTURE. Therefore, CardSN is of high-performance and energy-efficiency.

Study on energy-efficient reliability transmission for WSN

2008, 28(1):  25-28. 

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How to save the network energy, on the condition that the reliability of the data transmission is ensured, is an important subject for wireless sensor networks. Firstly, several key characteristics of wireless sensor networks communication links, such as high loss rate, obvious asymmetry, were found according to the experimental study. Secondly, the optimized power allocation in each node in the path was calculated using optimization theory; and a joint optimization algorithm was provided which connected routing metric with power control. Finally, the performance of the OPAETX algorithm was evaluated through simulation experiment; the results show that the optimizing algorithm can save the network energy on the condition that the reliability of the end to end is ensured.

P2P semantic route model with classified nodes

2008, 28(1):  29-32. 

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Maintenance of semantic information and selection of intelligence route in the P2P semantic overlay network are challenging problems. According to the small world theory in network, a new P2P semantic route model with classified nodes was proposed. First, node ontology was built in order to describe the network structure and the information in the node. Then, the formation of message routing and the method of nodes classification were created. At last, the algorithm of similar knowledge Searching and the algorithms of message routing were imported to support semantic information querying and routing. It is shown, through experimental evaluation, that the model and its algorithm can efficiently support the semantic searching functionalities in the P2P network.

Research into load balancing strategy of P2P service category

Nan Tao

2008, 28(1):  33-35. 

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With many similar characteristics between P2P and Web service, how to establish Web service network in P2P manner has been brought up under the spotlight. Service category is an efficient solution, but still lack of control on service community scale. Considering the Internet distribution, an algorithm for detecting community scale dynamically according to the community balancing factor was proposed. The related joining mechanism was also improved.

Reliability analysis model of cluster storage system by object grouping

Zhong LIU Zong-Bo LI Liu YANG

2008, 28(1):  36-38. 

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The reliability of the large-scale cluster storage system is one important research aspect in the related domain. A high-availability data objects placement algorithm was proposed. It groups objected into redundancy sets using RAID at the algorithm level. The redundancy allowed us to reconstruct any corrupted data objects and storage nodes when it failed and assured efficiently the high availability of storage system. The availability of storage system was quantitatively analyzed by using Markov reward model, and the computing results indicate the algorithm is efficient.

MAC-layer adaptation algorithm based on TCP control segment for wireless LANs

2008, 28(1):  39-41. 

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Due to the link characteristics of wireless channel, the performance of TCP decreases in WLAN networks. A MAC-layer adaptation algorithm based on TCP control segment was proposed. The scheme can enhance the throughput capacity of TCP control segment in the wireless channel and improve the transmission reliability of TCP control segment when there are access conflict and congestion in the wireless channel. Therefore, the transmission efficiency and reliability of TCP segments can be enhanced too. In this paper, the adaptable parameter of 802.11 MAC-layer was analyzed and the importance of the TCP control segment in transmission flow was discussed. The evaluation of the proposed scheme shows that the important gain in performance was obtained compared to that of traditional 802.11 MAC-layer.

Channel parameter estimation in CDMA systems based on UKF

[英]Zhang Zhi-Yu [中]张志禹

2008, 28(1):  42-44. 

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The estimation of time-delay for CDMA system is a nonlinear iterative process. The Unscented Kalman Filter (UKF) does not approximate the nonlinear system with a linear model as the Extended Kalman Filter (EKF) does, so estimation of channel coefficient and time-delay in CDMA transmit channel by UKF algorithm is more accurate than EKF. Concerning the Multiple Access Interference （MAI） and "near-far" effect, channel coefficient and time-delay for CDMA systems were estimated with the proposed method. The simulation results indicate that UKF can restrain MAI and "near-far" effect, and can also estimate the wireless channel parameter effectively.

Scheduling scheme of MAC layer for stratospheric telecommunication platform

Zhe WANG

2008, 28(1):  45-47. 

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To satisfy the protocol and requirements of different services flow of the stratospheric telecommunication platform, a scheduling scheme that could meet Medium Access Control (MAC) layer QoS and dynamic bandwidth allocation was proposed. The proposed scheduling scheme allocated up link and down link bandwidth not only to Mobile Station (MS) by Mobile Center Station (MCS) but also to all types of traffic in MS simultaneously and dynamically. At last, the simulation on the slot of different services flow, different delay characteristics of the traffic and different algorithms in the same services prove the feasibility of the scheme.

Research of handoff in integrating Ad Hoc networks into Internet

Zhi YANG Dong-Tang Ma

2008, 28(1):  48-51. 

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This paper firstly analyzed the drawbacks of handoff in Ad Hoc networks being integrated to Internet based on mobile IPv6. Local Agent and foreign Agent were introduced into MIPv6 in the handoff mechanism which supported intra mobility, and part of the mobility management ability of the home Agent was transferred to local Agent and foreign Agent, then the intra mobility could be shielded from the home Agent and correspondent node. The results show that the handoff time decreases greatly, when the inter-handoff probability is low, the average handoff time can be cut to 50% of the proactive handoff time under certain condition.

Data load balance model for multi-cluster grid

Yu-Tian HUANG Qingkui Chen

2008, 28(1):  52-55. 

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To improve the utilization efficiency of heterogeneous resources in Multi-Cluster Grid （MCG） composed of many computer clusters, a data load balance model was proposed. According to computation power, storage power, and communication power of query node, the performance model of query node was studied. By using data saturation, matrix of data load balance and data migration technology, system's data load balance mechanism was described. Experiment results show:The model can be fit for querying massive data.

Information security

Faster scalar multiplication algorithm based on addition chain

2008, 28(1):  56-58,6. 

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To improve the efficiency of scalar multiplication, a run-length addition chain of scalar was proposed. New scalar multiplication integrated with algorithms of direct computing 2Q+P, 2nR+S in field, sliding window algorithm and run-length algorithm. The addition chain length, storage and pre-computing would be decreased. Its efficiency has been enhanced about 53% than binary method, about 47.5% than NAF method, about 46.2% than run-length algorithm and about 42.2% than Windows method.

Research of mixed image element encryption algorithm based on chaotic system

2008, 28(1):  59-61. 

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On the basis of the definition of block image element, mixed image element and composite image element, this paper proposed a mixed image element encryption algorithm based on chaotic system. This paper offered the steps of information exchange between the recipient (Bob) and the sender (Alice) in detail and verified the security of the algorithm. The algorithm can avoid the degeneration problem of chaotic system character that was aroused by computer finite precision and effectively improve the ability of withstanding known-plaintext attack. This algorithm can effectively ensure the security of the information exchange on the platform.

Research of pairwise key establishment protocol in sensor networks

Ping Li JiaYing Wu

2008, 28(1):  62-64. 

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A number of isolated key-sharing component would be available in wireless sensor networks, due to random deployment of sensor nodes. In order to solve this problem, multi-nodes trust model based on trust relationship transfer was presented, along with the corresponding results key establishment protocol based on authentication in trust field. Simulation show that the presented protocol can achieve interconnection of components effectively, as well as nice performance on resilience of sensor nodes in the network. Thus, the security and effectiveness of the protocol are verified.

A high performance parallel schedule solution of network transport encryption in linux

2008, 28(1):  65-67,7. 

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This paper brought out and showed the implementation of a high-performance parallel network packets encryption schedule (HENC) in Linux system based on producer-consumer theory, in which a pointer of "transmiter" was used. After comparing the throughput in testing environment with general network packet encryption schedule in Linux system, we showed HENC was a better network packets encryption schedule when hardware encryption modular was used. Finally, we talked about the problems and the further way of improving HENC.

Balance analysis of four digital chaotic spread spectrum sequences

2008, 28(1):  68-70. 

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The research on the balance of chaotic sequence has important significance to spread-spectrum communication. The relationship between the balance and the parameter of four typical chaotic maps (Chebyshev, improved Logistic, Logistic and Tent) was discussed. The new numeric ranges of initial value and fractal parameter were decided, which provided reference for the generation of chaotic spread-spectrum sequence. Through the graphs of the four chaotic sequences' balance and the error-bit rate performance of these systems with the four chaotic sequences' map parameters, the new numeric ranges were validated. Both simulation results and the analysis show that the balance of Chebyshev is the best.

Improvement of structured multi-signature scheme with signers' intentions

Zecheng Wang Tao-zhi SI Zhi-bin LI

2008, 28(1):  71-73. 

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The security weakness of structured multi-signature scheme with signers' intentions was pointed out. It is that the signers' intentions could be modified by an inner or outer attacker, thus the security of this type of signature is tampered. By using a more secure signing algorithm to sign the signers' intentions, the problem was solved. The improved scheme not only has all the necessary security properties of this type of signature, but also has improvement in efficiency - shorter signature size, more efficient in communication and signing computation. The shortage of the new scheme is some decrease in the efficiency of verification.

DoS attack in mobile IPv6 network

Xin-Yu Yang

2008, 28(1):  74-76. 

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The principle of Mobile IPv6 (MIPv6) protocol was researched, and a summary of three main DoS attacks in MIPv6 network were given. A new solution to simulate DoS attacks in MIPv6 for the environment of NS-2 was presented. The simulation result shows that the DoS attacks cause great threats to MIPv6 network.

Property-based remote attestation in open network environment

Li Li ZENG Guo-sun CHEN Bo

2008, 28(1):  77-79. 

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To resolve many existing problems in integrity-based remote attestation of trusted platform, an abstract model of property-based remote attestation was put forward, in which the property of platforms was validated by the trusted third party. Then the model was described and validated explicitly by a logic security language. This new method enriches the security semantic of platform attestation and is more adapt to the impartial and open network environment.

Rule-based automated trust negotiation model

Ying-long Wang

2008, 28(1):  80-81,8. 

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In the Automated Trust Negotiation (ATN), access control policy regulates user's access to resource so as to protect sensitive information and resource. However, access control policy itself may contain sensitive information; its disclosure may result in privacy leakage. And policy's increases enhances the negotiation complexity. In order to handle such a dilemma, a rule-based ATN model, called Rule-Based Automated trust negotiation Model (RBAM), was proposed. RBAM treats all policies as rules, divides them into two parties, and introduces Agent to implement rules, which can reduce the complexity and improve negotiation efficiency.

Fast multi-pattern matching algorithm for intrusion detection

Chao-Qin GAO Yuan-Yan CHEN Mei LI

2008, 28(1):  82-84. 

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With network speed and the number of rules constantly increasing, pattern matching is becoming the bottleneck in Network Intrusion Detection System （NIDS）. This paper proposed a fast Wu-Manber-like multi-pattern matching algorithm for intrusion detection, called FWM. By subdividing the pattern group into two subgroups and dealing with the two subgroups in different methods, the FWM algorithm enhanced the efficiency of pattern matching. Experimental results show that, when pattern group contains the pattern that is less than three bytes, the FWM algorithm improves average performance by 29%~44% compared to the original NIDS pattern matching algorithm.

Matrix grid-based key pre-distribution in sensor networks

2008, 28(1):  85-87. 

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To solve the security problem of wireless sensor networks, the concept of matrix pool and matrix grid were put forward, upon which our key pre-distribution scheme was built. And in the matrix grid based scheme, encryption was introduced into the process of key transfer. Using Blom's key pre-distribution for reference, an efficient key pre-distribution scheme was presented for sensor networks.

Artificial intelligence

English accent assignment based on morphological rules and machine learning

2008, 28(1):  88-91. 

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Accent assignment of out-of-vocabulary is a very important component besides letter-to-phoneme Conversion in English Text-To-Speech (TTS). Considering that primary accent is much more important and simpler than secondary accent, their assignment was conducted separately. A hybrid algorithm of morphological rules and machine learning was presented to tackle the assignment of primary accent. And a machine learning algorithm was proposed to handle the assignment of secondary accent. After 10-fold cross validation, the average accuracy of primary and secondary accent assignment reached 94.4% and 86.9% respectively, and the total accuracy was 83.6%.

Ant algorithm with elitist strategy and vision detection for mobile robot path planning

2008, 28(1):  92-93,9. 

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Elitist ants were added to the algorithm, which not only developed the ant search scope, but also strengthened the ability of the ants to pass long space and the complex space. Vision detecting expanded ant's vision field and enhanced the ant to have "the far-sighted insight" in the exploration process.At the same time it reduced the ant exploration steps, which greatly improved the algorithm efficiency. The routing optimization function made the ant movement path to pull straight, shorten, which made the availability of route choosing enhanced. The grid division was used to sign the environment, and the grid side expressed the element information and the distance information, thus reducing the computation quantity of the algorithm.

Particle swarm optimization with stochastic local search

Gong-gui CHEN Jun-jie YANG Yong-fa SUN Jian-wei ZHONG

2008, 28(1):  94-96. 

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In Particle Swarm Optimization (PSO) algorithm, the acting of gBest particle during evolutionary process is important for attaining convergence. A new improved PSO algorithm called SLS-PSO was proposed in this paper. Based on the structure of basic PSO algorithm, the proposed algorithm searched local optimal solutions to gBest particle by adopting Stochastic Local Search (SLS) algorithm to improve the convergence performance during evolutionary process of PSO algorithm. Four well-designed test problems were used to evaluate the proposed algorithm. Compared with the basic PSO algorithm, the proposed algorithm shows its effectiveness and efficiency.

Application of dynamic-clustering-based fitness-sharing genetic algorithm to wind vector retrieval for scatterometer

Xue-tong Xie Wen-xian Yu Li-qing Guo Yu Fang

2008, 28(1):  97-100. 

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Wind vector retrieval is the key to scatterometer data processing. The design of traditional wind vector retrieval algorithm excessively depends on the detailed distribution shape of the objective function. Taking SeaWinds as an example, according to the multiple solution problem of wind vector retrieval and its ambiguity solution property, a wind vector retrieval algorithm was designed, which was based on the dynamic clustering niche genetic algorithm. By using some Level 2A data and the corresponding Level 2B data, the algorithm was validated. The experimental results indicate that the algorithm achieves good wind field results without using any transcendental knowledge of the objective function.

Adaptive invading genetic algorithm based on chaos search

2008, 28(1):  101-103. 

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By introducing the concept of invasion of biological systems into Genetic Algorithm (GA), a chaos-search-based Adaptive Invading Genetic Algorithm (AIGA) was proposed in this paper. The invading population, whose size was dynamically determined, was obtained through Chaos Search (CS). The expansion of the invading population was capable of propagating excellent genes among individuals and optimizing the gene structure of the population. And thus, it made the population evolve towards the global optimum. As a result, the algorithm was able to diminish the probability of being convergent to local minima prematurely. The proposed algorithm was applied to function optimization and pattern classification. And the experimental results show that this algorithm has the merits of fast convergence and global optimization.

Dynamic double-population particle swarm optimization algorithm for power system unit commitment

Dan LI Li-qun GAO Ke WANG Yue HUANG

2008, 28(1):  104-107. 

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Dynamic Double-population Particle Swarm Optimization (DDPSO) algorithm was presented to solve the problem that the standard PSO algorithm easily fell into a locally optimized point, where the population was divided into two sub-populations varying with their own evolutionary learning strategies and exchanging between them. The algorithm had been applied to power system Unit Commitment (UC). The DDPSO particle consisted of a two-dimensional real number matrix representing the generation schedule. According to the proposed coding manner, the DDPSO algorithm could directly solve UC. Simulation results show that the proposed method performs better in term of precision and convergence property.

Double-layer evolutionary model for N-player iterated prisoner's dilemma

2008, 28(1):  108-111. 

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Concerning the problem that cooperation in N-player Iterated Prisoner's Dilemma (NIPD) is hard to emerge when N is great, this paper researched the status of game both in the free competition mode and in the agreement competition mode. And imitating the strategy "Tit for Tat" in 2-IPD, it promoted the strategy "Simulated TFT". And combining the theories of co-evolution, it built up a double-layer evolutionary model, DL-NIPD, in which players and their aggregations, groups, can evolve in their own-layer respectively. Analysis of the numerical experiment results indicates that, under the free competition case, cooperation is usually easier to emerge in a small group of player than in a larger one, while depending on the straight-agreement and competition of groups, DL-NIPD can get a high rate of cooperation under any N.

Clonal selection algorithm based on multi-memory mechanism with applications to pattern recognition

Lei HUANG Di-ming HUANG

2008, 28(1):  112-115,119. 

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Currently in the research of artificial immune system, the clonal selection principle is commonly used in designing immune recognition algorithms. This paper described the general framework of CLONALG which was a clonal selection algorithm proposed by Castro, and pointed out that the convergence could not be guaranteed when it was applied to large-scale pattern recognition problems. A multi-memory mechanism was designed, based on which a new immune algorithm referred to as MCA was proposed and applied to pattern recognition problems. A new formula was proposed to calculate the mutation probability, which was a key factor in training memory antibodies. The results of experiments show that both the generalization capability and the recognition accuracy of MCA are better than that of CLONALG, and the MCA can be effectively applied to large-scale problems.

Speaker recognition based on multi-subsystems likelihood scores fusion

2008, 28(1):  116-119,119. 

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To describe an approach of speaker clustering based on multi-subsystems likelihood scores fusion to the text-independent speaker recognition system with short speech data in various telephone microphone channels. The registered speakers were aggregated into clusters with 2 types of speaker model similarity measures, namely, Kullback-Leibler Divergence (KLD) and Generalized Likelihood Ratio (GLR). A single-layer perception network was built for each cluster, fusing the likelihood scores of 3 sub-systems with the speaker features of MFCC, LPCC and SSFE, respectively. Concerning the robustness of SSFE system and recognition accuracy of the other 2 systems, the 3 sub-systems complement each other with the fusion network in each cluster. Experimental results on NIST SRE 05's database show a relative equal error rate reduction of 10.3% and 8.7%, with KLD and GLR, respectively, with respect to an all-speaker-shared fusion network.

Face recognition based on ensemble PCA

Zheng-Qun WANG Jun Zou Feng Liu

2008, 28(1):  120-121,124. 

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A classifiers ensemble approach based on Principal Component Analysis (PCA) was proposed. Lots of original classifiers were got from Random Subspace Method (RSM). According to their classification performance, their preservation scores were given, so the preferential ranks for classifiers preservation were ordered, by which a set of classifiers was selected from original classifiers. Theoretic analysis and experimental results in face database ORL show that this pattern classification method based on ensemble PCA is efficient for pattern recognition.

Symmetry based two-dimensional principal component analysis and its application to face recognition

2008, 28(1):  122-124. 

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This paper presented a Symmetry based Two-Dimensional Principal Component Analysis (STDPCA) on the basis of this idea of symmetry, which was introduced into Two-Dimensional Principal Component Analysis (TDPCA). Firstly, facial image was divided into the even symmetrical image and the odd symmetrical image. Then TDPCA was performed in the even symmetrical image and the odd symmetrical image for feature extraction, respectively. Therefore, STDPCA used effectively not only the advantages of TDPCA, but also the symmetrical properties of facial images. The experimental results on ORL and YALE database show the efficiency of STDPCA.

Study of intercept action algorithm based on proportional navigation in robot soccer

Yong Pu XingShe Zhou Yuying Wang

2008, 28(1):  125-126,130. 

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The process of missile or torpedo navigation to pursue a target is similar to the process of soccer robot intercepting a ball. By introducing the common used proportional navigation algorithm and its moving model, we can get a fire-new control method of soccer robot. The simulation experiment proves that this algorithm has good effect on intercepting, and if we can choose appropriate navigation control modulus according to different application requirements, the effect of intercept action would be satisfying.

Hierarchical speaker identification based on PCA and multi-reduced SVM

2008, 28(1):  127-130. 

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This paper proposed a new hierarchical speaker identification system based on Multi-Reduced Support Vector Machine （MRSVM） and Principal Component Analysis (PCA) classifier to reduce the recognition time of speaker identification. First get a coarse judge by a fast scan of all registered speaker using PCA classifier, and then get a final decision-making by the proposed MRSVM. And the MRSVM has two reduction steps: PCA and kernel-based fuzzy clustering are used to reduce the dimensions and amounts of training data respectively. The experimental results show that the training data, time and storage can be reduced remarkably by using our method, and the system has better robustness.

Utilizing particle swarm optimization to optimize hyper-parameters of SVM classifier

Dong WANG

2008, 28(1):  134-135,139. 

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Particle swarm optimization used for optimization selection for hyper-parameter of support vector machine classifier was designed and implemented utilizing global searching property of particle swarm optimization algorithm while the algorithm was used to solve combinatorial optimization problems. The method of individuals coding and evaluating was described in brief. The experimental statistic results demonstrate that the algorithm is effective and efficacious. In the end, some in-depth works are listed on the base of above-mentioned study.

Articles

Study on discovering frequent items algorithm for distributed data stream

2008, 28(1):  136-139. 

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To study the algorithms for discovering the frequent items of distributed data streams, a novel algorithm was applied to find the synopsis structures from leaf nodes to root node by Distributed Synopsis Algorithm (DSA), and minimize the communicated loads through the relevant diagrent under different conditions. The experiment verifies the efficiency of the algorithm and structure by real data sets.

Study on potential influence topic in on-line community

Jun-Bo GAO Bo-Wen An Xiao-Feng WANG

2008, 28(1):  140-142. 

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On-line community has become an important place for people to retrieve information and deliver comments. It consists of a large number of topics delivered by registered users. Concerning the shortage of traditional method for calculating influential topic, a new method was presented. By calculating word's influence on re-comment chain, our method can discover the potential influential topic in on-line community based on clusters of influential words. It can timely, exactly and conveniently provide important topic information to user and forum manager.

New algorithm for maximum flow algorithm in network with both node and edge capacity confined

xiangyang SHE

2008, 28(1):  143-145. 

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Concerning the problems in flow algorithm on network, a new algorithm with strong applicability was studied. The orientation path and residual network were defined, the new maximum flow algorithm in network with both node and edge capacity confined was put forward based on feasible flow decompose theorem and by way of the search in artificial intelligence. In the end, the algorithm was validated and compared by examples. Algorithm testing shows: The new maximum flow algorithm in network with both node and edge capacity confined is completely feasible and availability effective.

Study on Chinese-English corpus construction toward multiple-domain resources

Li Xiao-Guang Peng Wang Wei Zhang Daling Wang

2008, 28(1):  146-148. 

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With the consideration of the features of open, multiple-domain and layout regularity of bilingual resources on Web, a mixture probabilistic alignment model was proposed to reveal the domain-specific and position-specific characteristic for aligning texts. Compared to the traditional lengthen-based aligning model, the model in this paper achieves 37% and 40.4% improvement on precise and recall respectively with the extensive experiments.

Customer churn prediction on kernel principal component analysis feature abstraction

2008, 28(1):  149-151. 

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KPCA was introduced into customer churn prediction, and the corresponding feature abstraction method was presented. The prediction model was designed by combining Kernel Principal Component Analysis (KPCA) and Logistic regression. Experimental results of customer churn prediction for a telecommunication carrier show that the proposed method is superior to original attributes and PCA feature abstraction in hit rate, covering rate, accuracy rate and lift coefficient, which indicates that KPCA abstracts nonlinear features of customer data and provides an effective measurement for customer churn prediction.

Optimized Web information extraction based on XQuery

Shao-Fei CHEN

2008, 28(1):  152-154,. 

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Due to lack of the analysis of the adaptability of the Web page's characteristics, the current typical systems can hardly provide robust extraction rules. This paper proposed an optimized Web information extraction method which divided rules into three associated layers, suggested an optimized algorithm for extraction rules from the view of the precision and recall ratio through analyzing the adaptability of the page's characteristics, and expressed the complicated object rule in standard XQuery. Experiments indicate that our approach enhances the robustness and usability of the rules.

Method for multi-way spatial distance join query processing

2008, 28(1):  155-158. 

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A recursive non-incremental algorithm following a depth-first search was presented for solving multi-way spatial distance join query, which found the K n-tuples for the smallest distance value from n spatial datasets, where each dataset was stored in an R-tree. The user can not have any result until the algorithm ends. The algorithm adopts distance-based plane-sweep technique as optimization technique to effectively reduce disk accesses and CPU response time. Finally, efficiency of the algorithm is validated by experiment.

Automatic text categorization for patent data

Jian-An Jiang Jie-Ping Lu Wei-Wei Ni Zhi-Hui Sun

2008, 28(1):  159-161,. 

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At present, there are no practical and mature automatic text categorization methods for patent data. Therefore, this paper made a research on several key techniques about text categorization, improved the non-dictionary segment and weight calculation, and then proposed a hierarchical categorization method and an automatic text categorization framework for patent data. The experiment testifies that the system has a good classification accuracy and efficiency.

Data mining in P2P networks

Tian-Peng LIU

2008, 28(1):  162-164,. 

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To analyze both the operational mechanism of current distributed data mining and the characteristics of the P2P technology: non-centralized peer and asynchronism, by extending the iterative process of classical K-mean algorithm, a distributed data mining algorithm was designed in this paper to implement k-mean thinking in a P2P networks. This algorithm exchanges information only between directly connected nodes, and can cluster local data on each peer in a global view. Finally, simulation experiments show that the algorithm is effective and accurate.

Graphics and image processing

Study on color space conversion from CMYK to L*a*b*

Cong-Jun Cao Ming-Quan Zhou Yi Kang

2008, 28(1):  165-167. 

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Color space conversion is the key technology in color management,direct quality-detection of printing images and color separation. Therefore, it is very important to find out a accurate and practical transform from CMYK to L*a*b*. In this paper the dot colorimetric plane of four-color halftone printing based on optic phenomena was verified by the standard printing. Then the equation of transition from CMYK to L*a*b* was modeled by analyzing the colorimetric values of process printing patches based on mathematic statistical method and numerical analysis method. And its precision was discussed and the main reasons that influence the equation precision were analyzed.

Improved algorithm for vector data compression based on dynamic programming

2008, 28(1):  168-170. 

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To increase the storage capacity of mobile equipment and improve the transmission efficiency of vector data on network, this paper proposed a model and improved method of vector data compression based on dynamic programming algorithm. This method constructed a smallest error range by a reference path, that can be adjusted automatically. The experimental results show that this method is of higher compression ratio and smaller compression error.

Adaptive image watermarking algorithm based on block DCT transform and Arnold shuffling

Maoy-an FENG Bo FENG Chunlin SHEN

2008, 28(1):  171-173. 

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In this paper, we proposed an adaptive image watermarking algorithm based on DCT and Arnold shuffling transform. With the features of Human Visual System (HVS) sufficiently taken into account during embedding, embedding different watermarking energy into different DCT blocks made the algorithm adaptive. The experimental results show that the algorithm is robust to common digital image processing operations, especially to image cut.

Direct generation method of NURBS boundary surface

Ying WANG Ruo

2008, 28(1):  174-176,. 

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Because of the complexity of Non-Uniform Rational B-splines (NURBS) surface, the conventional NURBS surface generation method usually first constructs a Coons surface and then changes it into NURBS surface, which adds the operation complexity. To address this problem, an NURBS boundary surface direct generation method was proposed, which can directly construct a NURBS boundary surface by using four NURBS boundary curves. Compared with the traditional method，it need not convert Coons surface to NURBS surface and have a low computing cost. The experiments show the proposed method is simple and convenient, but the generated surface still has a high quality and good continuity.

Line detection based on Euclidean distance

2008, 28(1):  177-180. 

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To detect lines in digital image, this paper proposed a new algorithm. Different form traditional line detection algorithms, the algorithm does not search another coordinate transformation, but defines the line degree of a point in a curve as the sum of k Euclidean distance square between points centered at the point, and deduces that except limited points in the head and tail, points in a line segment will have the maximum line degree. Derived from this characteristic, the new algorithm detects line segments in a two-pass manner. Firstly, the points on a curve that obviously belonged to a line segment were selected by using Freeman chain-code. Secondly, the points that were continuous and had the maximum line degree were selected. The result shows the algorithm is stable, precise and fast.

Research of whole fairing and approximation algorithm of NURBS curve

LAN Hao De-xin Li

2008, 28(1):  181-183. 

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With regard to the accuracy and smoothness of a set of discrete data points approximation, this paper gave a whole fairing and approximation algorithm of cubic Non-Uniform Rational B-Spline (NURBS) curve. The algorithm constructed an objective function composed of least square, sum of curvatures on discrete points and sum of curvature varieties on discrete points, obtained a series of the best control points, adjusted weights using nonlinear optimization method, set up an approximation approach to verify the fitting errors and constructed a calculation procedure. At last, this paper displayed and analyzed the obtained curve in UG NX 4.0.

Application of adaptive genetic algorithm in license plate location

2008, 28(1):  184-186. 

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License Plate Recognition (LPR) plays an important role in Intelligent Transportation System and the license plate locating is the critical technique in the LPR. Because the traditional locating algorithm is not adaptive or robust, this paper proposed car license plate thick locating method based on the Adaptive Genetic Algorithm (AGA). First, use OTSU method to make license plate image binarization, and then use genetic algorithm to map the entire license plate matching search feature. With a fitness function formed by the area character vector, the optimal locating parameter of the plate area was found. It is proved by experiment that this locating method is strong and the locating effect is very good.

New method of curve modeling based on continuity for extension-Bézier curves

Gang HU Zhe LIU Hua-nan XU

2008, 28(1):  187-190,. 

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The extension of Bézier curves with shape control parameters has become the hot spot in computer aided geometric design. A new method of curve modeling based on continuity for Extension-Bézier curves was presented in this paper. This method first constructed a class polynomial curves called cubic extension (CE) Bézier curves with three shape parameter α, β, γ. CE-Bézier curves not only inherit the outstanding properties of cubic Bézier curve, but also are adjustable in shape and fit close to the control polygon. In order to overcome shortcomings that the circular arc and ellipse could not be accurately represented by CE-Bézier curves, this method used the continuity condition of CE-Bézier curves and C-Bézier curves to resolve the representation of circular arc and ellipse in CE-Bézier curve modeling. In addition, some applications of this method in curve and surface design were also discussed. The modeling examples illustrate that this method is valuable for computer aided geometric design.

Automatic mosaic of surveillance images based on SIFT feature matching

2008, 28(1):  191-194. 

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In this paper, an improved Scale Invariant Feature Transform (SIFT) feature-based approach for efficient automatic mosaic surveillance images was proposed. In the image registration step, SIFT Feature was extracted efficiently and reliable matching was carried out, and Random Sample Consensus （RANSAC） was improved to guarantee stability and decide the transformation parameters of the images stitching. In the image fuse step, a radiometric and color compensation stage allows the development of an automatic and seamless mosaicing system. The results show that our approach performs well, even in processing the surveillance images with low overlapping area, moving objects, shape differences and noise.

General composition method for optical-plate-based LCD multi-view stereo image

Xiao-Wei SONG Lei YANG

2008, 28(1):  195-198. 

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Multi-view stereo image composition is largely dependent on the type of multi-view stereo display device. Currently, optical-plate-based multi-view stereo LCD display is most popular, while there is lack of a general composition method for this kind of display. A new general composition method was proposed for the most popular optical-plate-based multi-view stereo LCD display. The method is made up of three parts, i.e. sub-pixel judgment, sub-pixel sub-sampling for each view, and sub-pixel arrangement and composition of each view. This method covers all the possibilities of optical-plate-based multi-view stereo LCD display, with good applicability and popularity. The correctness and validity of the proposed method is verified by experiments.

Video retrieval model based on multimodal information fusion

Jing ZHANG Hui YU

2008, 28(1):  199-201,. 

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In allusion to the complex requirement of query, a new video retrieval model based on multimodal information fusion was brought forward in this paper. It included multi-models like text retrieval, image query, semantic features extraction, and used relational algebra expression to fuse these multimodal information. Experimental results demonstrate that our method could fully utilize the advantages of multimodal information fusion based on relational expression in video retrieval, and achieve good performance on complex semantic video retrieval.

Image enhancement based on quantum-behaved particle swarm optimization

2008, 28(1):  202-204. 

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To improve the adaptability and versatility of image enhancement, a Quantum-behaved Particle Swarm Optimization (QPSO) algorithm approach to image enhancement was proposed, in which image enhancement was formulated as an optimization problem. And a new objective function was used to evaluate the algorithm's performance. Not many parameters of QPSO need to be adjusted and the randomicity of QPSO is strong, so QPSO can guarantee the efficiency and global convergence of algorithm. The efficiency and superiority of image enhancement based on QPSO algorithms can be confirmed by the simulation results.

Application of regularized EM algorithm with weighted wavelet in COSM

Gui-fan Sun Xiao-hai He Qing-chuan Tao

2008, 28(1):  205-207. 

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In the image restoration of Computational Optical Sectioning Microscopy (COSM), using regularized Expectation Maximization (EM) algorithm based on the depth-variant imaging model can not restore the details of image, and consume more time. In order to improve the restored results and reduce the restoration time, the combination of the regularized EM algorithm and weighted wavelet algorithm was proposed. Firstly, revise the wavelet coefficients of the images. Then, use the regularized EM algorithm to do restoration. Experiments show that the restoration result is improved and the iteration time is reduced. The efficiency is increased obviously.

Intra-frame motion compensation based on linear interpolation padding

2008, 28(1):  208-210. 

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Intra-frame motion compensation was considered to be one of the potential enhancements of H.264/AVC. A Linear Interpolation Padding (LIP) method was proposed to improve the intra-frame motion compensation. Compared to Adaptive Padding proposed by Dong, LIP can predict the pixels in padding zoom more precisely. And as a result, the efficiency of intra-frame motion compensation will be increased. Experimental results show that LIP can increase the number of macroblocks coded as intra-frame motion compensation by 4.58%~84.7%, and improve the overall rate-distortion performance.

Improvement of motion blurred direction identification based on Hough transform

2008, 28(1):  211-213. 

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Restoration of the motion blur images is highly dependent on estimation of motion blur parameters. The motion blurred direction identification based on Hough Transform, which was proposed by R. Lokhande et al., was improved. The improvement adopted more pretreatments, found more appropriate lines during the process of Hough Transform, and then gained the weighted means of their corresponding direction as the final result. The experiments show that, the improved algorithm has better precision and is more robust.

Core image segmentation method by combining watershed and ISODATA algorithm

Dai-sheng Luo

2008, 28(1):  214-215,. 

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Watershed based image segmentation can make the edge close and precise, but has the drawback of over-segmentation. ISODATA can conglomerate gravel, but has the edge bias error. Combining watersheds and ISODATA, this paper proposed an image segmentation method to solve these problems. Firstly, watershed segmentation algorithm was applied to get the initial over-segmentation image, and Iterative Self-Organizing Data Analysis Technique Algorithm (ISODATA) was applied to get the conglomeration image. Then, labeled images and inverse wavelet transform were used together to get the full - resolution image. The results based on ISODATA algorithm were applied to solve over-segmentation problem caused by watershed. Experimental results show that it is a practicable method for the image segmentation.

Robust estimation of optical flow based on linear brightness model

Zhao Bin

2008, 28(1):  216-219. 

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A robust optical flow algorithm for larger motion velocity and larger velocity change under large varying illumination was presented. A general linear brightness model was embedded in the gradient constraint equation, which improved algorithmic stability under large varying illumination. The anisotropic diffusion equation was introduced in the spatial oriented smoothness constraint, so that it can improve the computation of flow velocity in the motion discontinuities, according to these improvements, the differential optical flow algorithm based on multi-scale-space focusing was used. An invariant energy function under the linear variation of scales was obtained by normalizing the parameters. Motion compensation is introduced to iterative process, and then the error of brightness was decreased. The experimental results show that the algorithm proposed in this paper provides with good computation accuracy for lager motion velocity and larger velocity change, and the flow field of 100% density can be created.

Fast approach of randomized detection for multi-ellipse

Zi-Qiang Li Yue-ping He

2008, 28(1):  220-223. 

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For multi-ellipse detection, this paper proposed a randomized fast detection approach. It made use of randomly sampled one edge-point sampling randomly and locally searched two edge-points in an image and information of their neighborhoods to determine a candidate ellipse, then affirmed true ellipse for the candidate ellipse by affirming true circle for corresponding circle into which is transformed by the candidate ellipse. When determining a candidate ellipse, the number of points sampled randomly was maximally reduced, more non-ellipse points were eliminated, and therefore useless sample and calculation were reduced. Numerical experiments demonstrate that this approach has better robustness and can advance the detection speed compared with the existing algorithms.

Typical applications

Consistency analysis method of entity relationship of C4ISR architecture products

2008, 28(1):  224-225,. 

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According to multi-view architecture description methodology, the entities are overlapped in different products; it is the basic requirement to keep consistency of identical entities in different products. Based on DoD Architecture Framework 1.0, the consistency analysis methods was provided in the paper, in which entities relationships matrix was developed according to the architecture product, and consistency was judged by relationships matrix. Finally, the case of consistency analysis of relationship between operational node and operational activity was given, and the method has been proved feasible.

Defining software defect data

Ke-gang HAO

2008, 28(1):  226-228. 

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A systematic method was proposed to guide the defining of software defect data. According to the general goals and process of software defect management, the principles of defining software defect data and the features of a defect management tool were discussed, and an example was given to demonstrate how to define software defect data. A complete method of defining software defect data was proposed. Correct method of defining defect data is very important for software defect management.

Research and application of software measurement process for CMMI

2008, 28(1):  229-231. 

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This paper introduced a Goal-Regulations-Data-Result (GREDR) process framework of software measurement for Capability Maturity Model Integration (CMMI) in order to help the organization implement the software measurement that conforms to the CMMI model. From the result of the trial in our organization, the software measurement process can be accomplished through the framework systematically. At the same time, it can assist on the plan for measurement and improve the final effect.

Single pattern string exact matching algorithms based on hybrid strategy

Ke-Jin Hu

2008, 28(1):  232-235. 

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It is researched by comparing their time complexities of LDM, ILDM1, ILDM2 algorithm etc. with RF algorithm that only uses a smallest suffix automaton. The experiment shows that the time complexities of LDM, ILDM1 algorithms are poorer than that of RF algorithm, and there is no efficiency for the hybrid strategy in LDM, ILDM1. The experiment also finds that it is not the best strategy for middle and small alphabet that the forward finite state automaton is suspended when the length of pattern prefixes-R is not greater than half of m, the length of pattern string, in ILDM2 algorithm.

Online energy-efficient scheduling technique analysis for hard real-time mixed tasks

Dong-Song Zhang Shi-Yao Jin Tong Wu

2008, 28(1):  236-238,. 

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This paper analyzes energy-efficient scheduling techniques for mixed real-time tasks, deeply discusses an excellent online energy-efficient scheduling algorithm called On-Line Dynamic Voltage Scaling (OLDVS) in hard real-time systems, and shows the causes which result in the algorithm's shortcomings, i.e. slack time misses and slack time transfers. In order to improve its energy savings, the paper also presents various new means and makes a well exploration for future research.

Retrieval of plane geometry resource database based on dynamic geometry

Guo Yuan-hua 郭远华 Zhong-Qin BI

2008, 28(1):  239-241. 

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It is not satisfactory to retrieve similar geometry propositions in geometry resource databases in a traditional way. For plane geometry resource databases based on dynamic geometry, this paper provided a similar retrieval method using geometry characteristic information. Geometry characteristic information quantifies various geometry elements of a geometry proposition and can be extracted from drawing instruction sequences, this retrieval method can properly find out similar geometry propositions.

Improved light-weighted embedded secure file system model

Jian-Xin ZHU

2008, 28(1):  242-244. 

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How to protect the data stored in mobile device is one of the key technologies for various embedded systems. This paper focused on the research and implementation of a light-weighted embedded secure file system model for various mobile devices, especially those with restricted hardware resources, through adopting access control policy suitable for embedded system and optimizing the memory driver. The actual practice shows that this model can meet the performance requirements for embedded secure file system.

Quick algorithm for reconstructing line object adjacency relations

Ming-Xue LIAO Zhi-Hua FAN Xiao-Xin He

2008, 28(1):  245-247. 

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Based on known coordinates of lines, the time complexity of usual algorithm for reconstructing adjacency relation among n line objects usually is O(n*n); in theory, its optimal value is at least O(C) and C is the cardinal number of adjacency relation. Based on hashed-bucket sorting, a quick algorithm with O(n(1+1/r)) average time complexity and with O(n) space complexity was given to reconstruct adjacency relation where r was the ratio of number of buckets used in the algorithm to n. It was proved that the problem can not be solved by sorting algorithm without extra space. With necessary extra space, a two-pass sorting algorithm with O[n(lb n+1+2/r)] time complexity, was also given. Applications show that the performance of the quick algorithm is over about 1~3 orders of magnitude higher than that of the usual algorithm.

Design and implementation of an embedded flash player

Xiao-Hui SUN Jian Liu Chun Wang Xiao CHEN Jin-Lin WANG

2008, 28(1):  248-249,. 

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In order to meet the requirement of playing flash in embedded devices, a new design and implementation of flash player was proposed. It is suitable for memory and CPU constrained devices. Some methods that could improve the performance of the player were provided. This player has been used as a plug-in in an embedded browser.

Alert aggregation based on IDMEF and category

2008, 28(1):  250-253. 

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How to aggregate and reduce duplicated alerts from different Intrusion Detection System （IDS） is one of the most important problems in distributed IDS research area. The article proposed a type of Intrusion Detection Message Exchange Format (IDMEF) alert specification extending the alert class structure of IDMEF data model to universally define the format of the alerts originating from different IDS. In order to efficiently aggregate this new type of IDMEF alerts, the article proposed an improvement to the original algorithm that was based on category and similarity. The prototype of alert aggregation module and IDMEF alert generation module has been implemented on the Snort platform. Experiments on DARPA99 data sets demonstrate the effectiveness of our method.

Agent-based power quality monitoring virtual device

Tao LI

2008, 28(1):  254-256. 

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Concerning the large volume and real time requirement of data of power quality, virtual device model based on Agent was proposed in this article. Foundation for Intelligent Physical Agent was combined with P2P technology, and through cooperation of several Agents in communication, the bandwidth of network was fully utilized, and the transmission of real time data was guaranteed. The experiment and application demonstrate that Agents based on these technologies have effectiveness in power quality monitoring.

Teleoperation soccer robot system based on wireless network

2008, 28(1):  257-259,. 

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This paper presented a design and implementation of an Internet tele-robot soccer system based on Pocket PC. According to the sequences of requirement analysis, system design and implementation, the approach of system realization was described. After implementation, an experiment platform was constructed for the tele-operation research based on the wireless network. Then on this platform, further researches and experiments about the combination of controller's tactic and autonomous intelligence were carried out.

Design and implementation of an Internet-based platform for C language learning

2008, 28(1):  260-263. 

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A designing model and implementing method of an Internet-based system for C Language Learning was proposed, which used .NET platform. The communication between the system and the compiler of C Language was implemented by using redirect technology. More powerful compile and logic error-check function was provided in the system, which adopted C# Multi-thread technology and synchronous control theory. Object-Oriented design methods and C# Reflection technology was used to solve the problem of test-case scheduling, which made the system be extensible and robust. The system for C language learners is more powerful by implementing the logic error-check function that has not been provided by the former work.

Embedded system for video-based forest fire detection

2008, 28(1):  264-266. 

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Concerning the long continuous monitoring and high cost of our current forest fire remote monitoring, an embedded system for forest fire detection and alarm based on video was presented. The embedded processor firstly processed the video image from the forest monitoring camera by daytime or evening fire detection algorithm. It then sent the fire information to the monitoring center by wireless network for further processing only when potential abnormity really occurred. Long uninterrupted monitoring can be avoided in this way. Finally, in comparison with the other existing systems of the same kind, great value was shown to our forest fire detection.