Table of Content

01 May 2010, Volume 30 Issue 05

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Network and communications

Traffic-class oriented differentiate weight algorithm on heterogeneous wireless networks selection

Yu GAO Hua-sen ZENG

2010, 30(05):  1141-1144. 

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To meet the needs of Quality of Service (QoS) guarantee in heterogeneous wireless network selection, the relative importance of QoS parameters for each class of traffic defined by 3GPP was analyzed, and the QoS parameter weight for each class of traffic was calculated by Analytic Hierarchy Process (AHP). Then, a Traffic-class Oriented Differentiate Weight Algorithm (TODWA), which was based on the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), was proposed for heterogeneous wireless networks selection. At last, simulation results show that TODWA is better than average weight algorithm on deciding target network reasonably and balancing network loads efficiently.

Design and implementation of MAC protocol for wireless sensor network based on ARM

Yi-duo LIN De-yun GAO Lu-lu LIANG Si-dogn ZHANG

2010, 30(05):  1145-1148. 

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IEEE 802.15.4 standard has been one of the most suitable standards for the underlying protocol stack of Wireless Sensor Metwork (WSN) because of its low-rate, low power-consumption, and short-distance. An IEEE 802.15.4 Medium Access Control (MAC) layer protocol stack software was designed and implemented on ARM9 Linux platform after studying IEEE 802.15.4 MAC protocol stack. The software was released in the form of Linux character driver eventually. The results indicate that this software is of greater practicality and scalability.

New low-energy security routing protocol for wireless sensor network based on SPINS

Zhi-juan PENG Ru-chuan WANG

2010, 30(05):  1149-1152. 

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Low-Energy Adaptive Clustering Hierarchy (LEACH) protocol is a critical clustering hierarchy routing protocol for wireless sensor network. Lack of security measures makes it vulnerable to personation and laptop attacks, especially during the cluster set-up phase. A new low-energy secure routing protocol based on SPINS was proposed. It authenticated broadcast packets using μTESLA, distributed authenticated key to cluster-head and cluster-members using SNEP. In the proposed protocol, sensor nodes needed to verify whether the cluster-head was the node it claimed to be. They also needed to verify whether they could reach the cluster-head. If both checks were passed, then sensor nodes joined in the cluster. Security analysis shows that the proposed protocol realized confidentiality, integrity, freshness, identity authentication, two-way authentication and some other security objectives. Simulation results based on NS2 show that energy consumption of sensor nodes does not significantly increase, due to the sink node and cluster-heads undertaking most of safety related tasks.

Research on sampling algorithm for median query based on wireless sensor network

2010, 30(05):  1153-1155. 

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A Sampling Algorithm for Median Query (SAMQ) based on Wireless Sensor Network (WSN) was proposed. In SAMQ, each node in WSN created a fresh sample summarizing its own observed values and the received values from children nodes, and then broadcasted its subsequence to the parents. Finally, these samples were combined to a single sample in the root node whose data structure was far smaller than the size of the whole data set. The approximate value for median query could be obtained from the sample quickly. A shared channel was used to reduce packet loss. Analytical and experimental results show that the proposed algorithm has the advantages of low power consumption, small error range, and is able to significantly prolong network lifetime.

KNN query on P2P networks

2010, 30(05):  1156-1158. 

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KNN (K-Nearest Neighbor) query is a kind of similarity query. A majority of KNN query algorithms are intended for concentrated computing environment, which will easily lead to performance bottle-neck. P2P, the new distributed computing technology, can effectively overcome the performance bottle-neck highlighted in the concentrated computing environment. A KNN query approach based on iDisdance index in grouping P2P networks was put forward. In the precondition of distributed clustering index prune in searching of space, this approach effectively reduced the network communication overhead, thus the KNN query could be implemented in P2P. The simulation results prove its validity and influences on query spending from the group number and data distribution.

Self-adaptive compensation scheduling algorithm for wireless generalized processor sharing system

2010, 30(05):  1159-1162. 

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Concerning the error-prone and capacity time-varying features in wireless systems, a wireless Generalized Processor Sharing (GPS) algorithm with self-adaptive compensation was designed. It could support fairness and Quality of Service (QoS) requirement, and made compensation smoothly. This algorithm redefined virtual time and improved fair share in ideal GPS model into time-varying fair share which was dynamically adjusted by terminal good throughput. Both theoretical proof and simulation results show that this algorithm is more efficient than wireless fair service.

Research on centralized network selection in wireless heterogeneous access network

2010, 30(05):  1163-1165. 

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Aiming at solving the problem of selecting appropriate network for mobile users in wireless heterogeneous access network, an optimal model of network selection was proposed based on each access network's available bandwidth and delay parameter. Network selection was formulated as dynamic programming problem in multi-homing environment, and an algorithm of selecting access network based on dynamic programming was presented. Simulation results show that the proposed algorithm provides optimal utilization of network resource and meets users' requirements.

Search algorithm based on budget mechanism for unstructured P2P network

2010, 30(05):  1166-1170. 

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Most existing search algorithms for unstructured Peer-to-Peer (P2P) network use the Time To Live (TTL) mechanism to control the search depth of the search algorithm, which is effective in the control of the search message transmitted in the network and the blind search algorithm. However, there is a huge difference in the number of nodes searched by TTL-based algorithm even with the same search radius. And each search branch of the TTL-based algorithm can only search the same depth of the network, thus resulting in the unstable search efficiency, which can not be a good support for main current interest-domain oriented search algorithms. To solve this problem, the budget mechanism was used to replace the TTL mechanism, and the budget value was used to replace the traditional TTL value to control the depth of search and number of search nodes, which would ensure more stable number of search nodes and achieve different search branches using different search depth, give a better support for oriented search algorithms. Experiments show that search algorithm based on budget mechanism for unstructured P2P network has more stable number of searched nodes, a good orientation, and higher efficiency.

Data transfer technology based on overlay multi-pathing and parallel TCP

2010, 30(05):  1171-1175. 

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A new technology combining "parallel TCP" and "multi-pathing" was designed and implemented. It used overlay network nodes as interim nodes. Besides, in the process of data transmission, it used more than one excellent performance indirect path, and opened multiple TCP connections on each one. Three key problems were solved: how to select the path with higher performance; how to dynamically select the best parallel TCP connection number; how to dynamically arrange data packages in multiple paths according to network flow. The proposed technology is totally implemented based on application layer, and does not need to modify TCP protocol and route protocol, which improves the speed of data transmission simply and effectively.

Delay-constrained multicast routing algorithm based on optimized Floyd shortest path algorithm

2010, 30(05):  1176-1178. 

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An important issue in multicast communication is how to create an efficient and robust Steiner tree through using multicast routing algorithm. Based on the analysis of delay-constrained Steiner tree, the cost and computational complexity when constructing a multicast tree, starting from the practical requirements and optimizing shortest paths, a new algorithm named Algorithm of Optimizing Shortest Path based on MPH (AOSPMPH) was proposed. On the basis of Minimum cost Paths Heuristic (MPH), the proposed algorithm found the shortest path between nodes using optimized Floyd shortest path algorithm and selected the minimum cost path to meet the requirements of delay constraint to add into the multicast tree. By this way, a low cost multicast tree could be constructed. The simulation results show that AOSPMPH not only can construct delay-constrained multicast tree correctly, but also is of less cost and lower computational complexity than those of many other multicast algorithms.

Capacity analysis and simulation for downlink transmissions of BF-MIMO system

2010, 30(05):  1179-1182. 

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Intended for the combination of BeamForming (BF) and Multiple Input Multiple Output (MIMO), a generalized wireless transmission scheme named BF-MIMO was presented with a view to bring both advantages into full play and enhance the channel capacity and system performance. According to a series of transformations of the signals in the transmitter and receiver antenna pairs, a combined flat fading channel matrix was analyzed and formulated. Besides, based on the steering vector of transmitter sub-arrays, the closed-form expression of the channel capacity was also given. Finally, the capacity enhancement of the proposed scheme over traditional MIMO systems was demonstrated and verified by simulation results.

New mechanism of realizing time-synchronization in LAN based on data link layer

Hua-jin CHEN Jia-zhou HE

2010, 30(05):  1183-1187. 

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The precision of the common network time protocol is low when being realized in the application layer, while high in physical layer yet a definite hardware is in need. With reference to the WinPcap time stamps management method of the famous network packet pawing software, a new high precision relative time synchronization algorithm was implemented with pure software in data link layer. Besides, the software was tested under Windows XP circumstance in an abbreviated LAN. The result indicates that the proposed algorithm can attain synchronization precision within 100μs.

Improved congestion control algorithm

2010, 30(05):  1188-1190. 

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A Weight Sum-Based Random Early Detection (WHS-RED) algorithm was proposed to deal with network congestion. WHS-RED algorithm used the rate of change of queue lengths in networks to drop network packets. The mathematical model was established. Simulation results prove that the proposed algorithm reduces packet loss rate and bandwidth-delay, while maintaining network stability and reducing the jitter of the queue, which is better than that of the original RED algorithm.

Information security

Study on distributed certificate authority system based on multi-provider model

2010, 30(05):  1191-1193. 

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To improve the service ability and availability of Certificate Authority (CA) system in the Public Key Infrastructure (PKI), a distributed CA system based on the model of multi-provider was proposed, which can improve the CA's ability of survivability and fault-tolerant. On the basis of Quality of Service (QoS), an Analytical Hierarchy Process (AHP) approach with automatically modifying judgement matrix was proposed to estimate the quality of service, so that the best service could be selected quickly. The experimental results show that this strategy increases running efficiency of service request and meets the needs of user's QoS requirement.

Research and design of survivable network system inspired by biological immunology

2010, 30(05):  1194-1197. 

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The definition of survivability of network was discussed and a new definition on the premise of staying alive was made. The guiding principle of biological immune system to the network survivability was analyzed, and a method for the second development of survivable network system was presented. The survivability of system was controlled by many immune units which were autonomous and distributed. Each immune unit consisted of four logical parts: detection, identification, prevention, and self-adaptation and evolvement. The model, classification and implementation of the immune unit were given. The design is of certain distribution and self-adaptation.

Techniques for intrusion detection based on adaptive intuitionistic fuzzy reasoning

2010, 30(05):  1198-1201. 

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A technique for intrusion detection based on Adaptive Neuro-Intuitionistic Fuzzy Inference System (ANIFIS) was proposed with intuitionistic fuzzy set theory introduced into the area of information security. First, the properties and vulnerabilities of the existing intrusion detection methods were analyzed, and a model for intrusion detection on ANIFIS with Takagi-Sugeno type was established. Then, the inference rules of the system were devised, computational relations between layers of input and output and a synthesized computational expression of system output were ascertained. Subsequently, a learning algorithm of neural network was proposed, which could adjust network structure and study network parameters. Finally, the test results verify the validity of the technique and rationality of constructed model by providing intrusion detection instances with KDD CUP 99 dataset.

Intrusion detection based on rough set theory and kernel matching pursuit

2010, 30(05):  1202-1205. 

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An intrusion detection method combinding Rough Set (RS) theory and Kernel Matching Pursuit (KMP) algorithm was proposed. In virtue of the ability that rough set can decrease the amount of data and get rid of redundancy, the proposed method could reduce the amount of machine training data, and overcome the disadvantage of slow processing speed because of large amount data in Support Vector Machine (SVM) algorithms. Meanwhile, KMP algorithm, with the help of good classification and recognition, made a different definition of importance on each sample, so that the core of property set could be classified, and intrusion detection could be realized rapidly with high classification accuracy and high detection rate and so on. The experimental results show that this method is better than the method based on RS only and the method based on Artificial Immune (AI).

Generating stronger avalanche effect in MD5 algorithm

2010, 30(05):  1206-1208. 

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By studying the differential analysis attacks on MD5 algorithm, it was found that why the differential analysis attacks could be successful was due to the change of individual bits of message. The alteration only influenced a small part of chaining variable, and these few differences could be rectified after continuative loops. Then, the collision was generated, and the avalanche effect of the original MD5 algorithm could not prevent differential analysis attack. To enhance the security of MD5 algorithm, the sensitivity of the avalanche of the MD5 algorithm should be increased. The analytical results indicate that the modified MD5 with Variable Plaintext Function (VPF) can be more sensitive to the avalanche effect, so as to effectively prevent the differential analysis attack and increase the security of MD5.

New image encryption algorithm based on composite chaotic system

2010, 30(05):  1209-1211. 

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An image encryption scheme based on composite chaotic system was proposed. The encryption system used the one-dimensional Logistic chaotic maping and the three-dimensional Lorenz system to produce chaotic sequences, and chose different ways to deal with scrambling transformation and gray transformation for each pixel according to the structural characteristics of the image itself. The security analysis shows that the proposed image encryption scheme provides higher efficiency and larger key space, and it is very sensitive to the key and the plaintext. It is characterized by excellent diffusion and confusion properties, which can resist the known-plaintext attacks and chosen-plaintext attacks.

Reversible data hiding for color images based on piecewise difference expansion

XIONG Zhi-yong WANG Jiang-qing

2010, 30(05):  1212-1216. 

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Concerning the drawbacks of relatively large location map and the quality decline of stego-images from excessive modulation to pixels of Tian's algorithm, a reversible data hiding algorithm for color images based on piecewise difference expansion was proposed. This algorithm used correlation of color components to decrease difference and disperse smaller expansion to two components, and used piecewise difference expansion and bit plane replacing to embed data information, and the quantity of un-expandable difference was decreased. Changeability of difference was used to locate unchangeable difference, so the payload capacity could be increased. The experimental results show that the payload capacity and the quality of stego-image are significantly improved, compared with other new or classical algorithms.

Digital audio dual watermarking scheme based on wavelet packet analysis

2010, 30(05):  1217-1220. 

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Aiming at solving the problems of previous dual watermarking algorithm, such as poor robustness and inaccurate positioning, a wavelet packet analysis-based digital audio dual watermarking scheme was presented. In this scheme, zero-watermarking and semi-fragile watermarking were embedded into the low-frequency coefficients and the intermediate low-frequency coefficients of wavelet packet decomposition for the original audio signal. The robustness of improved zero-watermarking algorithm has been greatly increased; therefore, the copyright protection of audio signals can be completed better; binary watermark image was embedded in the intermediate low-frequency coefficients by quantization different from the previous algorithm requiring to convert two-dimensional image to one-dimensional sequence, which did not affect zero-watermarking extraction. The algorithm has good robustness in resisting a series of conventional treatment and amplitude scaling, can not only examine the malicious tampering location of the watermark image, but also locate the tampering position of original vector audio, so it achieves the content authentication of the audio signal truly.

Stream cipher algorithm based on chaos

2010, 30(05):  1221-1223. 

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A chaotic stream cipher was designed by utilizing feed forward model. The sequence generated by Linear Feedback Shift Register (LFSR) was used as the initialization sequence. Logistic map and Chebyshev map were used as filtering functions. Furthermore, the chaotic stream cipher also included compression transformation, S-box transformation used in SMS4 algorithm, memory transformation and swap transformation. The results of analysis and experiment prove that the proposed stream cipher owns sufficient safety and higher encryption speed.

Proxy blind signature scheme based on hyperelliptic curve

2010, 30(05):  1224-1226. 

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Analyzing the algebra basis about hyperelliptic curve and its Jacobian discrete logarithm problem, a new proxy blind signature scheme of multivriate linear transformation based on hyperelliptic curve was proposed. The scheme owned the characteristics of both proxy signature and blind signature, and its correctness, safety and efficiency were analyzed. The scheme can be widely used in digital signature fields about the e-voting, e-commerce and so on.

Aanalysis and improvement of two designated verifier signature schemes

2010, 30(05):  1227-1229. 

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Two identity-based designated verifier signature schemes, which were proposed by Zhang and Li-Zheng-Zhu respectively, were analyzed. It was shown that two schemes did not satisfy the security requirements of designated verifier signature. Zhang's scheme did not meet the unforgeability requirement; Li-Zheng-Zhu's scheme did not have designated verification as although the non-designated-verifier could check the validity of the signatures. Then the schemes were improved. The improved Zhang's scheme owns unforgeability property, and has the same efficiency as the Zhang's. The improved Li-Zheng-Zhu's scheme owns designated verification property; moreover, the improved scheme has reduced one bilinear paring and is more efficient than the Li-Zheng-Zhu's.

Research on private permission in RBAC role inheritance

2010, 30(05):  1230-1232. 

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To improve the flexibility of controlling the depth of permission inheritance, the concept of threshold of privatization was introduced and a method based on it was proposed. Because the depth was defined as the difference between inheritance value and threshold of privatization, it could be changed by adjusting the threshold of privatization, with the precondition that the adjustment would not violate the static separation of duty. An algorithm was given to detect whether the adjustment would violate the static separation of duty. Through analyzing the relationship between permissions of static separation of duty and user's permissions, the algorithm minimized the number of users that need to be considered. Consequently, the time complexity of this algorithm is much lower than the one considering all users.

Blind digital watermarking scheme against scaling attack

2010, 30(05):  1233-1235. 

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By embedding the watermarking with synchronous information frames in DCT domain and constructing a grid of difference feature points with fixed interval and fixed difference in space domain, a blind digital watermarking scheme against scaling attack was designed. The grid of difference feature points was defined, the embedding and extracting methods were given, and the algorithm for obtaining scaling factors was also presented. The experimental results show that the proposed scheme is robust to scaling attack.

Design and implementation of multi-user encryption file system based on eCryptfs

2010, 30(05):  1236-1238. 

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Encryption file system such as eCryptfs can prevent the leakage of information when storage media is lost or stolen. But it can not guarantee the data security when many users online access the system at the same time, because once one user can access the encryption data, the other users can access the data too. A capability mechanism based on keys was put forward to solve the problem, and then the method was used to design and implement a multi-user encryption file system based on eCryptfs to ensure that only those users with keys can access the encryption data.

Semi-fragile digital watermarking algorithm for image content authentication

2010, 30(05):  1239-1242. 

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A semi-fragile digital watermarking algorithm was proposed to verify the authenticity and integrity of image content. Firstly, the algorithm extracted the edge of the scaled image as the feature information, and the feature information was chaotically modulated and ciphered with the private key to generate watermark information. Secondly, the watermark information was embedded into the wavelet domain of the host image by using Human Visual System (HVS). Finally, a user could extract the feature information from the watermarked image with the public key, and compared it with the reconstructed feature information of the watermarked image to achieve authentication. The experimental results show that the proposed algorithm has the immunity to common image operation, and can also achieve accurate authentication and tampering localization to malicious processing.

Test and analysis of trusted platform module data protection

2010, 30(05):  1243-1245. 

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The concept of trusted computing was introduced. In particular, concerning the trusted computing principle of trusted computing platform alliance, the Trusted Platform Module (TPM) was expounded. The unique characteristics of data protection, Binding and Sealing, were tested. The test results show that the trusted platform's data protection capacity is obviously insufficient and the computing power of the trusted computing platform needs to be further improved.

Pattern recognition

Bar code localization by extracting edge lines

2010, 30(05):  1246-1250. 

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Concerning the problems of recognizing bar code using image processing method, an effective and rapid algorithm was proposed to localize bar code through extracting edge lines. In this algorithm, a threshold value was obtained firstly by Otsu binary method from the original gray-level image. Pixels with gray values smaller than the threshold value were considered. The edge lines were extracted by sequential interlaced scanning in both row and column directions. Then the whole image was divided into strips of the same size. A starting strip was determined according to the position of the center point and the number of edge points distributed in strips. In starting strip, lines were detected by using edge points in the bottom of small ladder of a digital line, and angles of these lines were computed. Simulation compared the effect and running time of Sobel edge detector, Hough transformation, and the proposed algorithm. And the results prove the validity, rapidity and reliability of the proposed algorithm.

Traffic lights recognition algorithm based on Lab color space and template match

2010, 30(05):  1251-1254. 

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Traffic lights recognition is important for the intelligent vehicles research. A real-time traffic lights recognition method was presented. Firstly, the image was pre-processed by morphological operations. And then the candidate areas were found according to the samples of three kinds of traffic light got from Lab color space, which describes red, green, yellow color more effectively. Then, the candidate areas were filtered by traffic lights' shape characteristics. After that, three kinds of traffic lights templates, which were surrounded by a black rectangular box, were designed and used to confirm the candidate areas. At last, the results were validated by statistical methods. The experimental results show that the method is effective.

Automatic location of 3D facial feature points based on local shape map

2010, 30(05):  1255-1258. 

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Accurate location of face feature points is one of the key steps in 3D face recognition. A fully automatic locating algorithm for 3D facial nose tip and inner eye corner in different views was presented, which relied on a statistical model combining Local Shape Map (LSM) and local shape index, and the statistical radius of the local shape map was adaptively determined by error analysis. The experimental results on the CASIA 3D face database demonstrate that this method performs more precise location than heuristic algorithm and curvature-based method.

Key words location of the fax images based on connected component analysis and SVM

2010, 30(05):  1259-1261. 

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Locating the telephone number region is a very important technology in telephone number recognition of the fax images. After realizing a relative precise page analysis on the fax images by adopting the Connected Component Analysis (CCA) to form comparatively whole word regions, the features of horizontal traversing times and spatial distribution were abstracted to form feature vector of fifty-one dimensions. The multi-class Support Vector Machine (SVM) based on normal decision tree was introduced to achieve the key words location. The experimental results show that the method can realize the location quickly and effectively, and it is valuable in applications.

Voice activity detection algorithm based on sub-band weighting

2010, 30(05):  1262-1265. 

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To reduce the influence of noise and the frame delay of Decision-Directed (DD) parameter estimation algorithm on the robustness of Voice Activity Detection (VAD), Two-Step Noise Reduction (TSNR) technique was used to track the priori SNR of the current frame to improve the estimation accuracy of parameters in speech transient. Then, based on the frequency-selective property of noise signals, frequency spectrum was split into sub-bands to isolate noise corruption within particular sub-bands, so that the sub-bands weighting algorithm, in which sub-bands features were combined with their reliability to provide judgment, was constructed. The experiments show that the sub-band weighting method is superior to those full-band ones such as Sohn, Cho and G.729 B.

Improvement of background extraction and updating algorithm

2010, 30(05):  1266-1267. 

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In view of the limitation of the existing methods, a new algorithm of background extraction and updating was proposed. The interval pixel value belonging to the video stream was calculated to extract background. The edge detection method was referred to analyze the area of continuous change when there was stagnant vehicle in the current background image. The testing results demonstrate that the proposed method can be well adapted to the application of the complicated situation with markedly improved accuracy, and it is simple and suitable for real-time detection.

Data mining and artificial intelligence

Community recommendation algorithm based on dynamic attributes similarity of nodes in social networks

2010, 30(05):  1268-1272. 

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Community recommendation helps users find their interested communities and is becoming an important task in social networks analysis. According to the dynamic property of social networks，the evolvement of social networks，the behavior properties of individuals and the link relationships of nodes，the formal representation methods for the dynamic community and its nodes' dynamic attributes were studied. The computation method for dynamic attributes similarity of nodes and a community recommendation algorithm based on dynamic attributes similarity of nodes were proposed. The proposed algorithm can overcome the limitation in the other algorithms, recommending community to an individual only through its direct linking individuals. The experimental results show that the recommendation precision is improved and the method is effective to the community recommendation in dynamic social networks.

Normalized mutual information feature selection method based on Renyi's quadratic entropy

2010, 30(05):  1273-1276. 

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Normalized mutual information feature selection method was proposed based on quadratic Renyi's entropy. This method could efficiently estimate the mutual information, so that the computational complexity was greatly reduced. At the same time, the normalized mutual information feature selection method and embedding method were combined to get a two-stage feature selection algorithm, which could find more characteristic feature subsets. The experimental results compared with the other similar algorithms show that the proposed method can effectively reduce the computational complexity.

Improved fuzzy clustering algorithm

2010, 30(05):  1277-1279. 

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In traditional Fuzzy C-Means （FCM） algorithm, the user must give the number of clusters in advance and the objective function converges slowly. To solve these problems, a new algorithm for finding the best number of clusters was proposed with introducing granular analysis principle into FCM clustering algorithm, and density function algorithm was adopted to initialize the cluster centers. The experimental results show that the proposed algorithm can obtain reasonable and effective number of clusters. Compared with the stochastic initialization, this algorithm has fewer iterations and has faster speed to converge.

Weighted non-negative matrix factorization for incomplete dataset

2010, 30(05):  1280-1283. 

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Nonnegative Matrix Factorization （NMF） is a new method for feature extraction and data dimension reduction. It has an advantage over traditional algorithms in the simple implementation and the interpretability of factorization form and factorization result. But NMF could not decompose the samples matrix when it is incomplete. However, when dealing with incomplete dataset, NMFI (Weighted Non-negative Matrix Factorization for Incomplete Dataset) made use of random repair to decrease the error and weighted method to control weights of the samples, which could weaken the disturbance of missing data as much as possible. In addition, NMFI used regional weight for further reducing the impact of missing data in critical region. The experimental results demonstrate that NMFI can effectively extract information from retained data and reduce the influence of missing data.

Entropy-based algorithm to detect relative outliers in dynamic environment

2010, 30(05):  1284-1286. 

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An algorithm for detecting relative outliers in dynamic environment based on information entropy was proposed. When an object was inserted into or deleted from the dataset, the algorithm made it unnecessary to compute the values of Relative Outlier Factor (ROF) for all objects in dataset, only need to compute for affected objects. The experimental results indicate that the running time of this algorithm is less than that of the original algorithm in dynamic environment.

Hybrid recommendation approach based on incremental learning

REN Lei

2010, 30(05):  1287-1289. 

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Recommendation is a kind of personalized service in the adaptive information system, and it can provide personalized information according to individual information needs. Concerning the issues of the user profiling granularity and the sparsity of user-item matrix in the classical collaborative filtering, a hybrid recommendation approach named WHHR was proposed based on incremental learning. WHHR implemented user modeling with Widrow-Hoff learning and predicted ratings by collaborative filtering. The experimental results demonstrate that the proposed approach outperforms other similar ones in convergence and accuracy.

New hybrid intelligent optimization algorithm and its application in multi-objective optimization

2010, 30(05):  1290-1292. 

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After analyzing the disadvantages of the slower convergence property and lower accuracy in Artificial Fish-Swarm Algorithm (AFSA), a new hybrid intelligent optimization algorithm was proposed based on phased optimization and variable parameter optimization as well as some relevant rules in tabu search algorithm. In this algorithm, the optimization process was divided into two phases, one was to lock the neighborhood of the optimal solution or partial solution, the other was to obtain the optimal solution of high-precision. Each phase set different parameters and combined the tabu search algorithm to improve convergence speed and accuracy of optimal solutions. The simulation results show that the proposed algorithm can greatly improve the ability of seeking the global excellent result, convergence speed and accuracy. As for the multi-objective optimization problem, the proposed algorithm can also improve the quality of Pareto optimal solutions, enlarge the distribution area of decisions and maintain diversity in decision-making.

Enhanced particle swarm optimization algorithm

2010, 30(05):  1293-1296. 

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An Enhanced Particle Swarm Optimization (EPSO) algorithm was proposed to overcome the disadvantage of PSO such as easily falling into local optimal at the latter part of the evolution. In this algorithm, when particle fell into local extremum point, the algorithm enhanced its ability of searching global optimal value by enhancing the particle's self-study ability, the other relative particles' ability of exploring new search space and the information communication in particles. The experimental results indicate that the new method has good ability of searching optimal value.

Shortest-path algorithm based on direct/indirect adjacent edge concept

2010, 30(05):  1297-1299. 

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The complex networking graph was studied to solve the shortest-path problem with definite track. The concept of direct/indirect adjacent edges was proposed which extended the concept of path to that of line and improved the storage of the adjacency matrix of the simple graph. The space storage structure was used to store the complex networking graph based on the concept of the direct/indirect adjacent edges. The shortest-path algorithm was designed, which used the public transportation search as the example. The theoretical analysis and experimental results show that this algorithm is better than Dijkstra algorithm in terms of time and space.

Novel incremental updating algorithm for frequent subtrees

2010, 30(05):  1300-1303. 

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The incremental update for frequent subtrees was discussed and a novel incremental updating algorithm for frequent subtrees was proposed. The concept of effective tree collection and incremental strategy were put forward, which did not need re-run tree mining algorithm during update mining and could make full use of the existing data, and need scan database only once. Subtree pruning strategy was put forward to reduce the number of subtrees distinguishing isomorphism during update mining, which improved the operational efficiency of the algorithm. The experimental results show that the proposed algorithm is effective and feasible and has significant operation efficiency.

Case retrieval algorithm based on domain ontology in intelligent recommendation system of e-commerce

2010, 30(05):  1304-1308. 

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In view of the shortcomings of the traditional e-commerce recommendation algorithm, the case retrieval algorithm of synthetic semantic similarity was developed in this paper. Through the concept semantic similarity of weighted average commodity, type-based attribute semantic similarity and data-based type attribute value similarity, the comprehensive similarity of the case was calculated. The proposed algorithm solved the problem of low efficiency and inferior precision that calculating the similarity only depended on the attribute value and did not consider semantic and attribute type influence in the traditional recommendation algorithm. The e-commerce intelligence recommendation system framework was designed based on domain ontology cooperated with case reasoning. Through extracting the semantic essential factor in the commercial domain ontology to express the case, the case solution space was opened up to assist user retrieval and complete the commodity recommendation. The experimental results prove that this algorithm is effective and accurate.

Software process technology

Study on reusable test case

2010, 30(05):  1309-1311. 

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The feasibility and necessity of test case reuse were analyzed. The characteristics of reusable test case were studied, and the process of reuse-oriented test case design was presented. Based on the reusable test cases, a new software test model was proposed. The factors to describe a reusable test case systemically were given. Based on above research, the systematic description, standard designing and effective application of the reusable test case were solved, and a framework for reuse-oriented software test engineering management was provided.

Adaptive failure detection model based on message delay prediction

2010, 30(05):  1312-1315. 

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Failure detection is a key technology to realize high availability. It usually uses overtime mechanism to determine whether a process fails or not. But old failure detectors without adaptive mechanism can not meet the requirements of Quality of Service (QoS) of applications all the time because of the instability of the network. Adaptive failure detection requires that failure detectors can dynamically adjust the detection quality according to the variations of applications and the load of the network. A new failure detection model based on the predicted message delay was proposed on the basis of researching and analyzing the existing adaptive failure detection algorithms. An adaptive failure detection algorithm named PA-AFD based on the prediction from historical message delay was realized. The experimental results and analysis show that the algorithm can relieve the affect of message delay on the failure detection while ensuring the accuracy and integrity of detection.

Synthesized heuristic task scheduling algorithm for heterogeneous system

2010, 30(05):  1316-1320. 

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The list-scheduling algorithm driven by priority chooses tasks to schedule only by one attribute. But in the case of that different tasks should have the same priority, it can not work well. Therefore, a new synthesized heuristic algorithm called HCPFS was proposed. There were three levels of priority in the algorithm to choose task. First, the tasks in critical path have the highest priority. Secondly, the tasks with longer path to exit task should be selected, and then the tasks with more successors were chosen to schedule. The algorithm took duplication method and insertion method in the process of scheduling task. The experimental results in randomly generated graphs and sets of task graphs show that HCPFS performs well compared with HEFT and HCNF in heterogeneous environment.

Design and implementation of flexible and configuration RFID middleware for mobile devices

2010, 30(05):  1321-1323. 

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In RFID middleware, huge data are concentrated on the server, which leads to pressure on the performance. A flexible and configurable RFID middleware named Sea Mobile Middleware (SMM) was proposed for mobile device. SMM can be applied to the mobile device, has good platform independence, and can be deployed in different operating systems. In SMM, the devices are abstracted as the objects. Users can control and manage different mobile devices through User Interface （UI） and standard Web interface. Simultaneously, SMM provides the function of data synchronization. The experimental results show that SMM has low energy consumption, can relieve server pressure, and improve system performance.

Research on Java reflection-driven rules engine technology

2010, 30(05):  1324-1326. 

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Java reflection-driven rules engine technology focuses on the real-time lacking of current widely used rule search engines, and implements the rule-executing search engine using the reflective technology. In this engine, rules were loaded and executed dynamically, which made up for the disadvantages of other rule search engines. Meanwhile, loading the data source using reflective technology ensures the diversity of data sources, and no need of pre-building the data model.

Process analyzing method based on virtual machine

2010, 30(05):  1327-1330. 

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In view of the shortcomings of the existing process analyzing methods, a new method was proposed based on virtual environment of Windows platform. This method captured the current thread by analyzing virtual machine's memory under host, got the current process by the kernel data structures, and set zero among the memory to kill the process. The physical address of memory could be worked out by using the base address of page table. The experimental result shows that the proposed method can quickly detect process, effectively kill the process, and maintain the host security at the same time.

Graphics and image processing

Improved exemplar-based image completion algorithm of high reliability

2010, 30(05):  1331-1332. 

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An image completion method based on the exiting exemplar-based image completion idea was proposed by improving the filling order and target patch matching process. The algorithm proposed by Criminisi was analyzed, and a new confusion measuring was used to establish the filling order of the target patch, which considered "having one and the only one" when computing the similarity within patches and filled the target patch with highest reliability. The process of computing confusion coefficient integrated selecting the highest priority target patch with searching the corresponding matching patch to avoid cumulative error. The experiments for large object removal on real images show that the proposed method can efficiently handle large regions of complex background by producing more plausible effect.

Core image inpainting based on total variation model

2010, 30(05):  1333-1334. 

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To solve the problem of lost information of scanned core image, an inpainting algorithm based on total variation model was presented. Using the information of the reference pixels in the neighborhood area of the inpainted area, the information was diffused to the inpainted area. The neighborhood relativity coefficient was introduced weighing the influence on target pixel point by inpainting neighborhood boundary. The experimental results show that the new method improves the inpainting effect, and is effective for core image inpainting.

Fast multi-thresholding approach

2010, 30(05):  1335-1337. 

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It is really time-consuming for Otsu to seek the optimal threshold for the image composed of multiple targets. Therefore, a simple and efficient histogram-based approach for multi-threshold was proposed. The gray range of the object image was divided into two classes with a threshold value. Following this, the two classes were divided into four classes again by applying the Otsu's bisection method to each of the divided sub-ranges. The experimental results show that the proposed method is suitable for image segmentation, and can be efficiently used for pattern matching and face recognition.

Definition of a kind of image distance and its application in scrambling quality evaluation

2010, 30(05):  1338-1343. 

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Considering the shortcoming of Euclidean distance in factually measuring image differentia degree, and taking account of the fact that the image gray information at arbitrary position is closely associated with that of its neighbor, a new kind of image distance based on neighbor gray information was proposed, and an evaluation function of describing image scrambling quality was constructed based on this new image distance. The experimental results show that the proposed method is more effective in describing the image scrambling degree and reflecting the relation between the number of iterations in the scrambling techniques and the scrambling degree, which largely consists with human vision. Besides, for different images, the proposed evaluation method can reflect to some extent the effect of scrambling transformation in each scrambling stage.

Image segmentation based on local ant colony optimization

2010, 30(05):  1344-1346. 

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To solve the problem that single threshold cannot take care of the situation of each pixel when illumination varies, noise exists or background image gray changes dramatically, an improved image binary segmentation based on local ant colony algorithm was proposed. Within different image areas, different iteration numbers and steps were set for ants to achieve superior image segmentation results. The experimental results indicate the proposed method can enhance segmentation accuracy and reduce running time.

New wetland change detection method based on improved independent component analysis

2010, 30(05):  1347-1350. 

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Taking Honghu wetland in Hubei province as the study area, and using two ETM+ images acquired on July 27, 2002 and July 9, 2005 respectively, a new wetland change detection method based on improved Independent Component Analysis (ICA) was poposed. Firstly, the traditional ICA algorithm was improved in two aspects: the initial value determination and iterative process. Secondly, Tasseled cap transformation was taken on original images and their wetland components were extracted for ICA transformation. Finally, based on the obtained independent component that represents the possible changed areas, adaptive threshold segmentation method was used to get the final changed areas. The experimental results show that the proposed algorithm has higher accuracy than traditional ICA algorithm and post-classification comparison algorithm.

Image de-noising algorithm using adaptive threshold based on multi-wavelet nonsubsampled Contourlet transform

2010, 30(05):  1351-1355. 

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To constrain the drawback of the image de-noising due to the lack of translation invariance and redundancy of original Contourlet transform, a new image de-noising algorithm was proposed based on multi-wavelet nonsubsampled Contourlet transform and Bayes Shrink adaptive threshold, which used multi-wavelet for multi-scale decomposing and nonsubsampled filter banks for multi-direction decomposing, then improved Bayes Shrink adaptive threshold method according to the relation among decomposed sub bands. The experimental results show that the Signal-to-Noise Ratio (SNR) values of the de-noising images are improved significantly compared with the existing algorithm. The proposed algorithm has reduced pseudo-Gibbs phenomena effectively and preserved more details and edge information of the image.

Structure of adaptive group of pictures for distributed video coding

2010, 30(05):  1356-1358. 

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Distributed Video Code (DVC) has gained more attention due to its low encoding complexity. Side information is one of the key factors influencing the rate-distortion performance. However, the correlation noise statistics describing the relationship between the frame to be encoded and the side information available at the decoder is not spatially stationary, and fixed Group of Pictures (GOP) will result in quality degradation of the side information. An adaptive GOP was proposed, which checked the block detail-level by analyzing its texture energy and modified the temporal structure (i.e. the length of GOP). 〖JP2〗The experimental results show that the proposed scheme can improve the overall performance and achieve the gain of Peak Signal-to-Noise Ratio (PSNR) about 1.8-2dB compared with the fixed one, meanwhile maintaining a low encode complexity.

Construction and application of rational q-Bernstein-Bézier curves

HUANG RiPeng

2010, 30(05):  1359-1362. 

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Rational Bernstein-Bézier curve has been applied widely in computer-aided design and computer graphics. To construct a kind of rational q-Bernstein-Bézier curves based on classical Bernstein-Bézier curves, de Casteljau algorithm and q-Bernstein polynomials were studied. Some properties, the algorithm for computing curves, the technique concerning subdivision and degree elevation of curves were also discussed. A family of rational Bernstein-Bézier curves could be obtained by changing the value of q. The results indicate that the rational curves have strong flexibility. At last, the generalization of rational q- Bernstein-Bézier curves was proved to be effective by conic curve and representation digital image interpolation.

Typical applications

Research on architecture of collaborative work platform for industrial-chain enterprises cluster

2010, 30(05):  1363-1366. 

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By analyzing and modeling the industrial-chain-oriented inter-enterprise collaborative relationship management and user management, an open architecture of industrial-chain platform, fulfilling the platform function and data exchange dynamic evolution, was presented. Then, the function interface based on components was established, and the method for building distributed business functions, registering the business functions to platform and authorizing the functions to users was proposed. And data interface based on Web Service Agent and XML-based rule-base was put forward; therefore, the dynamic extension of data exchange centered on platform was achieved. The achievements were applied to the cooperative commerce platform of auto industrial-chain, and the availability of the architecture for dynamic evolution requirements of the platform was verified.

Research of affective computing in intelligent virtual environment

2010, 30(05):  1367-1370. 

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To equip the Agent with emotions, enhance its fidelity and natural interaction with human beings and to satisfy the real-time requirement in intelligent virtual environment, according to basic emotion theory and cognitive evaluation theory in psychology, an emotion model based on fuzzy rules was proposed. Firstly, "emotion factor" was generated according to the emotion elicitation rules based on fuzzy IF-THEN rules. Then a nonlinear function restricted by personality, emotion factor and emotion state at the previous moment were used to compute emotion strength. The simulation result shows that this model can simulate the fuzzy and nonlinear characteristic of human emotion to a certain extent, and more importantly, it is easy to realize by computer program.

Data reuse in sliding window based on blocked storage

2010, 30(05):  1371-1375. 

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Sliding window operation is widely used in the typical applications based on reconfigurable system, such as image processing, pattern recognition and digital signal processing. But the efficiency of sliding window circuit generated by reconfigurable compiling system is not high, and limited by redundant storage, waiting operation and so on. In view of this, a data reuse method in sliding window based on blocked storage was proposed to increases data throughput. Through parallel access to window data, the proposed method reduced memory access time and improved the performance of the hardware circuit. The experiments show that this approach can accelerate sliding window circuit. In three typical examples of sliding window, the performance of program enhances by 7.0-9.0 times.

Measurement of system resources health based on state space and its application

2010, 30(05):  1376-1378. 

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Based on the design of testability for modern computer system, concerning the health measurement of system resources, resources were depicted through state space， and both linear and nonlinear parameters' curves were analyzed by using centrifugal degree calculation of resources test parameters. Health degree of parameter state was calculated to provide a health measurement approach. Besides, a specific method of determining the parameters' weight based on sensitivity was established, and the architecture was constructed for resources health measurement and application in embedded system. The methods can be employed practically to measure health status of system resources.

Multiple-compression of DNA sequence data

2010, 30(05):  1379-1382. 

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The multiple-compression concept was proposed based on the characteristics of DNA sequence data. The first step of multiple-compression is to enlarge the alphabet. Firstly, DNA sequence data was encoded by 0/1 coding, and then every eight bits was transformed into an ASCII character. Through this step, the former DNA sequence data with only four characters would be enlarged to 256 characters. Secondly, the enlarged DNA sequence data was compressed for the second time with Huffman coding compression algorithm based on statistical model and Burrows-Wheeler coding algorithm based on transition model separately. Finally, the compression performances of all algorithms were compared. The results show that the multiple-compression algorithm is better than others in terms of compression ratio.

Method for SAR imaging and anti-jamming by alternate frequency modulation

2010, 30(05):  1383-1385. 

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A method of alternating frequency modulation ratio was proposed to enhance the capabilities of suppressing Digital Radio Frequency Memory Cheat Jamming (DRFMCJ) for SAR. Thus, frequency modulation ratio of the transmit signals and the jamming signals differed. The jamming signal could be removed away through match filter, and cheat jamming could be restrained. The effects of the imaging and anti-jamming using alternate frequency modulation ratio were simulated. The simulation result shows that the method is effective.

Hardware implementation of task management of μC/OS-Ⅱ

2010, 30(05):  1386-1389. 

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Since the real-time operating system kernel uses up a lot of system resources, it will reduce the enforceability of the application. In order to resolve this problem, a hardware real-time operating system was designed based on FPGA, and the task management of the μC/OS-Ⅱ based on hardware was implemented. The waiting list of tasks was designed by on-chip registers of FPGA, with the corresponding access module designed by hardware circuit, saving the system time wasted due to accessing memory frequently. Through the design of the TCB-based on-chip registers and the task scheduler based on combinational circuits, the potential of the multi-task parallelism was given to its full play. The system adopted VHDL, and simulated through the ISE 8.2 software. The simulation results show that the hardware implementation of the system reduces the running time efficiently and makes it possible to be applied in time-critical systems.

Non-backtracking multipath algorithm for test pattern generation

2010, 30(05):  1390-1393. 

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A Non-Backtracking MultiPath (NBMP) algorithm constructed singular cubes containing primary inputs and fault driving cubes connected with primary outputs, and produced test patterns by using generated singular cubes and fault driving cubes. It adopted non-backtracking strategy and multipath searching strategy during processing. The time complexity is proved to approximate linearity by the time complexity analysis and experimental results. Moreover, the fault coverage of test pattern involving eight biggest ISCAS85 benchmarks show that NBMP algorithm is superior to the traditional test generation algorithm.

Nonlinear periodic time series model

2010, 30(05):  1394-1397. 

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In combination with finite mixture modeling, mixture periodical autoregressive moving average (MPARMA) models were introduced to fit periodic time series with asymmetric and multimodal distributions, the stationary condition of such series was derived, and the application of Expectation Maximization (EM) algorithm was discussed. The new model was evaluated by analyzing the PM10 concentrations.

Realtime simulation of rain and snow in large-scale scene based on GPU particle system

2010, 30(05):  1398-1401. 

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Three-dimensional effect of rain and snow scenery realized by means of particle system can be greatly enhanced. Traditionally, the particle system based on CPU will occupy a considerable amount of CPU operation time so that it is hard to satisfy the need of realtime simulation. To resolve this problem, a particle system based on GPU was put forward to simulate rain and snow scenery. In this system, dead time particles were reused to form new particles in the eye coordinates. In the meantime, point position of particles was transformed to rectangle position in the Geometry Shader, so as to relieve CPU from the complex voluminous geometry operation. The number of particles in the scenery was largely increased, and thus enhancing the realtime effect and fidelity of the simulation.

Research on new virtual e-book based on finger point location algorithm

2010, 30(05):  1402-1405. 

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In order to break down the mode of traditional virtual e-book which can only wave arm to turn pages, an innovative interactive mode of virtual e-book was designed. Firstly, the image captured by the infrared detecting system was preprocessed to extract target feature. Then, the traversal searching algorithm was used to extract the finger point and get its accurate position. Then, the finger point information was mapped into mouse driver, and the innovative interaction mode was implemented according to the offset of inter-frame finger point. New virtual e-book system platform was built to verify the algorithms and the interactive mode, and an application case on Zhangjiagang Science Museum was given.

Mid-term conflict detection algorithm of multi-route conflict probability

2010, 30(05):  1406-1409. 

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After analyzing the route error of flight, an idea of using approximate analytical approach to estimate conflict probability between airplanes was proposed. To adapt for multi-route-segement in China, a new improved mid-term conflict detection algorithm was presented. This method considered the minimum distance point in flight, found out the five minimum distance points in the prediction time as the cumulative process of route error, and then the combined route error of two airplanes encounting could be more accurately described. The results of the simulation indicate analytical approach can meet the real-time requirements of air traffic control, and can be applied to the actual air traffic control system.

Cultural quantum algorithm for digital filter design

2010, 30(05):  1410-1414. 

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The essence of the digital filter design is multi-parameter optimization. In order to realize efficient digital filter, its design was firstly transformed into the constrained optimization problem, and then the Cultural Quantum (CQ) algorithm was used to search optimal value of filter design parameters in the parameter space with parallel search. The proposed cultural quantum algorithm was a multi-dimensional search algorithm for optimization of real numbers, which used mechanisms of the quantum and cultural evolution to update the quantum population space. The computer simulations show that Finite Impulse Response (FIR) and Infinite Impulse Response (IIR) digital filters based on CQ are superior to the filters based on Particle Swarm Optimization (PSO), Quantum Particle Swarm Optimization (QPSO) and Adaptive Quantum Particle Swarm Optimization (AQPSO) in terms of convergence speed and optimization effect.

Spectral classification of polarimetric SAR images based on polarimetric similarity

2010, 30(05):  1415-1417. 

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Aiming at the classification of polarimetric Synthetic Aperture Radar (SAR) images, a new approach using spectral clustering was propsed. The propsed method combined the polarimetic similarities of targets and spectral theory. It took two scattering parameters of the similarity characteristics of the target as input and used two-dimensional graph weights function instead of one-dimensional graph weights function to seek power value. It made the sampling points classification and the feature vector classification consistent to realize the classification of polarimetic SAR image. Experimental results show that the classification got by the method above is better than that got by K-means methods.

High resolution algorithm for direction of arrival estimation based on modified propagator method

2010, 30(05):  1418-1420. 

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A modified propagator algorithm was presented to achieve the high resolution direction of arrival (DOA) estimation by introducing cyclostationarity and conjugate data rearrangement, which made the correlation matrix more precise and effectively eliminate the influence of the noise and interference signal. Compared with the conventional eigen subspace algorithms, the presented algorithm has lower computational complexity with insignificant performance degradation because of avoiding Eigen Value Decomposition (EVD) of the covariance matrix. The simulation results demonstrate its effectiveness．

Approach for enhancing error-correcting capability of T-DMB system

2010, 30(05):  1421-1424. 

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Through analyzing the outer coding frame in Terrestrial-Digital Multimedia Broadcasting (T-DMB) mobile TV system and making use of the fact that the value of stuffing bytes in TS packets is set, an algorithm was proposed to detect the stuffing bytes section and correct the errors contained in this section before the Reed-Solomon (RS) decoding process. Then the locational relationship between the codewords before and after the deinterleaving process was analyzed. Based on that relationship, for the packets that could not be decoded by the normal error-correcting RS decoder, the proposed algorithm can predict error locations to perform both error and erasure correction, which results in the enhancement of error-correcting capability for T-DMB system and the improvement of the video and audio quality.

CNGI based video surveillance system

2010, 30(05):  1425-1427. 

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Supported by the project of China Next Generation Internet (CNGI), a large-scale deployable, carrier-level and multiple modes video surveillance system was designed and developed. The framework and implementation of video surveillance system were proposed. The system was divided into five main models including service management, calling process, Authentication, Authorization, Accounting (AAA), audit management and operation support system. The functions, structure and interactions of those models were described in detail. The test of this system application on CNGI has been completed, which proves that the system can satisfy the requirement of the large-scale deployment and carrier-level video surveillance service to society.

ESPRIT spatial spectrum estimation algorithm based on subspace tracking

2010, 30(05):  1428-1430. 

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In reality, the receiving antenna and the radiation sources are commonly found relatively moving, and the performance of traditional high-resolution algorithm will be severely curtailed. An adaptive Direction of Arrival (DOA) estimation algorithm based on fast and stable subspace tracking method was proposed for the above issues. And ESPRIT algorithm was adopted to estimate the DOA without eigen decomposition, thus the novel algorithm has lower computational complexity than the conventional algorithms. The simulation results show that, compared with the power iteration method based DOA estimation algorithm, the proposed algorithm possesses better estimation performance.