Table of Content

01 December 2006, Volume 26 Issue 12

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Network and communications

Cluster heads optimized clustering algorithm for wireless sensor networks and its performance simulations

2006, 26(12):  2787-2788. 

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Based on the study of LEACH, a clustering hierarchy algorithm named cluster heads optimized algorithm was proposed. The algorithm periodically put all nodes into several temporary clusters distributed evenly in geographical position, and then selected a cluster head in every temporary cluster. While selecting the cluster head, the principle of protecting the lowest energy node should be followed, the selected cluster head should be as close as the lowest energy node.Simulation results show that, compared with LEACH, the algorithm can enable the cluster heads to distribute more evenly in the network, postpone the emergency of the first dead node，and increase the number of data received at the base station.

Service discovery based on process analysis

2006, 26(12):  2789-2792. 

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After analyzing some recent service matching algorithms, a new service matching algorithm based on process analysis was proposed. Using the information in service process during matching, more sophisticated IO matching could be done, and incomplete output matching could be dealt with. By using process-based service discovery algorithm, recall ratio could be improved. The results from comparison experiments verify the efficiency of the new algorithm.

New blind channel estimation algorithm in orthogonal spacetime block codes system

2006, 26(12):  2793-2795. 

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A QR factorization based blind estimation algorithm has good performance. By combining the QR factorization based algorithm with the special structure of Orthogonal space-time block code, a new blind estimation algorithm in OSTBC was proposed. Compared with the traditional blind estimation methods, the proposed algorithm has much lower computational costs. And the Monte-Carlo simulations show that when the SNR is low, the proposed algorithm outperforms the subspace method based blind estimation algorithm.

New method of L2-Trigger based on the Handoff of mobile communication systems

2006, 26(12):  2796-2799. 

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In order to satisfy real-time applications, L2-Trigger has been proposed to trigger layer 3 handoff ahead to decrease the handoff delay of mobile IP. But some problems such as misty indications and ambiguous trigger techniques have been found in former methods. A new L2-Trigger method and a routes updating protocol named Double Routes Pre-Registration were put forward. This method will eliminate the registration delay when Mobile Node (MN) moves from one network to another.

Using logic to optimise the semantic Web query language processing

2006, 26(12):  2800-2802. 

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In order to achieve query translation and optimization in the context of the SeRQL RDF query language, the method of using Prolog to manipulate RDF graphs was proposed, as well as the algorithm of translating SeRQL to Prolog goals. Besides, a structured mapping from language to semantics has been provided and the performance of the storage module for use in Prolog has been demonstrated.

Implementation of an improved Chord algorithm in the file sharing system

2006, 26(12):  2803-2805. 

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Chord is a kind of comparatively effective P2P route algorithm, and it can locate the target resources quickly. But because of the over low utilization of the message during transmission, the routing table suffers serious information redundancy and great network maintenance is needed. Therefore, this text put forward an improved Chord arithmetic, and resolved some existing problems. As a result, the network search efficiency was raised and fault-tolerance ability of the network was strengthened. The improved one was implemented in a design of the file sharing system and proved to be effective.

Flow and capacity distribution of computer communication networks based on multicriteria satisfactory optimization

2006, 26(12):  2806-2808. 

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The theory of satisfactory optimization was applied to computer communication networks, and the multi-criteria satisfactory optimization method for computer communication networks was proposed. By designing satisfactory rate functions of performance indexes and synthesis satisfactory rate function of computer communication networks,satisfactory optimization mathematic model for computer communication networks was constructed. The satisfactory optimization of capacity and flow distribution was performed based on improved genetic algorithm that has rapid convergence and good global search capability. Experimental results show that the computer communication network designed by this algorithm has more satisfactory performances than traditional methods.

Analysis and study on behaviors of P2P file sharing system

2006, 26(12):  2809-2812. 

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Some behaviors are very important to the robustness and reliability of P2P file sharing system. Therefore, it is necessary to think of these questions while designing and deploying P2P file system. To study the behavior characteristics of P2P file sharing system, the forming reasons of these behaviors and the influences of these behaviors on the system were analyzed. Besides, some measurements and comparisons were made to some of the behaviors. Whats more, how these behaviors vary were described and some effective ways to deal with these behaviors were summarized.

Location predictor for WLAN based on partial information

2006, 26(12):  2813-2816. 

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Some problems existing in the available themes, especially the state space expansion and knowledge aging problem in Order-k Markov predictors, were analyzed. A new predictor model was proposed. Prediction accuracy of the proposed predictor was compared with that of Order-k Markov predictors by using a trace of the mobility patterns of 1,200 users on real Wi-Fi wireless network. The new model's good practicability is shown by the results. It saves more space and time than Order-1 Markov predictor that is the simplest in Order-k Markov predictors, and outperforms Order-2 Markov predictor that has the best prediction performance.

Design of conformance testing system for ultra-lightweight IPv6 protocol stack

2006, 26(12):  2817-2819. 

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Brief description of an ultra-lightweight IPv6 protocol stack which is designed by Net-lab was given at first. Then based on conformance test standard TTCN-3, a conformance test system was given. The test model and test system frame were also described. The detailed way to describe test case and implementation of the test system were introduced too.

Study of the coverage control of the wireless sensor nodes based on communication conditions

2006, 26(12):  2820-2822. 

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Sensor nodes which are organized in clusters could use either single hop or multi-hop mode of communication to send their data to their respective cluster heads. The energy cost problem of wireless sensor networks was analysed, and the energy cost of sensor nodes in the both modes of communication was studied. The optimum numbers of cluster heads were confirmed by using mode of data aggregation, and it is proved that the method which fits the coverage control of wireless sensor networks is feasible.

Reference nets-based model for Web service composition

2006, 26(12):  2823-2825. 

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In order to support the reliability of Web service composition, the modeling technique for Web service composition based on reference nets was proposed. And the formal semantics of service composition could be described accurately. With this technique, the models of eight basic constructs were built which were in the control flow of Web service composition. Besides, the modeling steps were given. The model of Web service composition was built and simulated using Renew 2.0.1 and the validity of this technique was verified furthermore.

Overlay network for DHT-based P2P resource locating service

2006, 26(12):  2826-2828. 

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A kind of the structured P2P overlay network named LAOverlay was proposed. The thought of the group was adopted and two-layer Hash architecture was constructed to make the resource of the underlying network node be mapped in a nearby node. The problem that resources location methods had little relationship with real physics structure was resolved, and steady, reliable and inquiring extensive resources location was achieved.

Graphics and image processing

Nonlinear filtering algorithm based on local texture direction probability statistic model

2006, 26(12):  2829-2831. 

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In order to more effectively make use of local features to restore the noise-infected image, a nonlinear filtering algorithm based on local texture direction probability statistic model was proposed. The proposed algorithm utilizes Radon transform to determine texture direction probability density distribution of local areas of images, and then applies probability statistic model to estimate the middle pixel's gray value according to its neighbour pixels. The performance of the proposed method was evaluated with several sets of images contaminated by pulse noise and Gaussian noise. The experimental results show the superiorities of this method including the abilities of denoising and preserving edges and details of images especially for images with pulse noise and Gaussian noise.

Reconstruction of support vector machines for non-uniform sampled curve

2006, 26(12):  2832-2834. 

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Theories of regression Support Vector Machines (SVM) were briefly introduced,and then the conditions for the complete reconstruction of non-uniformly sampled curve was educed by frame theory. Based on the above mentioned, the same non-uniformly sampled curve was reconstructed by using frame iterative algorithm and regression support vector machines method respectively, and the reconstruction results show if the regression support vector machines method can reconstruct non-uniformly sampled curve stably, some necessary conditions must be fulfilled for the sampled data set.

Blink detection and eye tracking

2006, 26(12):  2835-2837. 

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A method was proposed to detect and track eyes and to recognize the opening and shutting of eyes in a real-time video stream. Blink detection was used for eyes positioning. An inner eye corner filter was used to locate the positions of inner eye corner accurately. The eye was tracked in real time by detecting the inner eye corner. Open eye template could be created online and dynamically updated. The opening or shutting of eyes could be recognized using correlation with an online open eye template. Experimental results indicate that the proposed algorithm can locate the positions of inner eye corner with an accuracy rate of more than 98%． An accuracy rate of 97.5% in blink detection is obtained using the proposed method at a processing rate of 50 fields per second.

No-reference digital image quality evaluation based on perceptual masking

2006, 26(12):  2838-2840. 

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From the angle of noise detection, this paper presents a mask-based no-reference approach of image quality assessment. Firstly, the approach improved Hosaka plots method and wiped out the limits on image size. Then this improved method was applied to the image to make plots and modified directional gradients were employed to abstract sub-blocks' noises. Finally, a new image PSNR was computed according to the pollution degree. Experimental results show that this no-reference approach can not only make the subjective assessment in line with the objective one, but also feature a low computational load.

ROI decision algorithm based on advanced visual properties

2006, 26(12):  2841-2842. 

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A rapid algorithm to evaluate the importance of different regions in the video scenes was proposed. The principle of the algorithm is to make corresponding visual importance estimates of segmented regions by analyzing the advanced visual properties. As a result, the subjective visual ROI values were ascertained, which reflected the importance of each region. The experimental results show that the ROI values produced by the proposed algorithm accord with human subjective conclusions well. Besides, the computation cost of the algorithm is not high, and it has high utility value.

Load balancing method based on render history in cluster rendering

2006, 26(12):  2843-2847. 

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Performance of sort-first cluster parallel rendering system is greatly influenced by load balance. Static load balancing method is poorly adaptive. As to dynamical methods, those based on geometry data traversing are not practical, and those based on coarse geometry data granularity can be put into practice but depend on the pretreatment of geometry data. Therefore, a practical load balancing method based on render history was proposed. This method does not depend on geometry data, but utilizes render time of previous frame and its information of load distribution as the input of load balancing for the next frame's rendering. The method is tested on cluster rendering platform and the test results show that it is very effective.

Application of hierarchical multi-phase C-V method based on narrow band to MRI image segmentation

Jun-Tao Xue

2006, 26(12):  2848-2850. 

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A hierarchical multi-phase C-V method based on narrow band was proposed. Several stages are involved in the proposed method, and each stage needs just one level set. Besides, in every segmentation stage only the points of narrow band need to be dealt with. Therefore, the computation work has been greatly reduced compared with the multi-phase C-V method. Experimental results of MRI (Magnetic Resonance Imaging) image show that the proposed method is efficient and stable. The segmentation effect and speed is improved greatly when the image has complex structure.

Various pose face recognition with one front training sample

2006, 26(12):  2851-2853. 

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Almost all algorithms for face recognition have tight relationship with the images number of each person. The recognition rate increases with the increasing training number of each class. But in applications, it is not practical to ask for many training images from each person. A new method, which can generate the simulated images of face after rotating an angle, was proposed. It generalized the method of Fisherfaces and uncorrelated image projection discriminant analysis to one sample per person. The recognition rates of Principal Component Analysis (PCA), Fisherfaces, and Two dimension's PCA (2DPCA) were also studied. The experimental results on FERET face－databases indicate that after adding virtual images, the recognition rates increase greatly, and the best recognition rate has improved by 28.2%.

Computing color histogram based on perceptual characteristics

2006, 26(12):  2854-2855. 

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The perceptual characteristics of color's Hue, Saturation and Value (HSV) were studied. To measure the information carried by different colors, a function was proposed by virtue of Weber-Fechner law and the hexagonal-pyramid model of HSV color space. It was used later to compute a perception-based color histogram. Contrast experiment proves the effectiveness of the new color histogram in image retrieval.

Study of virtual octree model for volume data

Guang-Xian LU

2006, 26(12):  2856-2859. 

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Pointer-based octree and linear octree have their limitations either on time efficiency or storage efficiency. A pointerless/non-location-code virtual octree model based on multi-z-order-curves was proposed. In terms of time, the virtual octree provides fast access to the octree nodes by regularly partitioned node blocks and their index. In terms of storage, the virtual octree provides good compression by pointerless/non-location-code nodes and the node combination method based on regularly partitioned blocks. Test results show that the virtual octree has access efficiency as fast as pointer-based octree, and storage compression as good as linear octree. It is a good volume data model, and has wide application in volume graphics related areas.

Improved motion path editing

2006, 26(12):  2860-2862. 

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Motion path editing was introduced. A new algorithm which kept the velocity of foot movement unchanged was put forward to solve the footstep slip in editing process. In this algorithm, constraint technique was used. First, location of foot was computed in every frame as initial constraint. When the motion path was changed, constraints were updated automatically according to the principle of unchanged velocity of foot movement. This automatic method reduces the manual interference existing in traditional ones. Then per-frame Inverse Kinematics algorithm was used to solve foot-constraints in real time. Experimental results show that the proposed algorithm solves footstep slip effectively.

Steganalysis based on co-ocurrence matrix in DCT domain for JPEG images

2006, 26(12):  2863-2865. 

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A new steganalysis scheme based on co-occurrence matrix in DCT domain for JPEG images was proposed. A total of 120 dimensional feature vectors were derived from the co-occurrence matrix, which was calculated directly in DCT domain and was sensitive to the data embedding process. Then, SVM was used to classify the 120 dimensional feature vectors. The experimental results for 4 kinds of popular JPEG steganographic schemes (F5, Outguess, Model based steganography with and without deblocking) have demonstrated that the proposed scheme outperforms the existing steganalysis techniques in both detection rate and speed.

New color transferring algorithm based on multidimensional eigenvector and ANN searching technology

2006, 26(12):  2866-2868. 

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Transferring Color to Grayscale Image is to adjust chromatic channels of grayscale image automatically. The classic algorithms of color transferring named Welsh was analyzed,and its two main disadvantages were pointed out. After introduced a new multidimensional eigenvector for pixels with high frequency texture information, a new color transferring algorithm was proposed, which utilizing ANN searching technology. The new algorithm fixes the two main disadvantages of classic algorithm and greatly improves the transferring result.

Fast inter-prediction mode decision for H.264/AVC

2006, 26(12):  2874-2876. 

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A full search method used in reference software of H.264 comes at a cost of greatly increased complexity of encoder. A new scheme was proposed to optimize block mode decision and improve the efficiency of the encoder in H.264/AVC significantly. Homogeneous area, zero vector and block merging method were combined in this scheme. The experimental results of JM model show that the new scheme is able to achieve a reduction of 60% encoding time on average, with a negligible average peak signal-noise ratio (PSNR) loss(<0.03dB) and bit rate increase (<4%) compared with the original H.264/AVC reference software.

3D face pose estimation based on affine transformation and linear regression

2006, 26(12):  2877-2879. 

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A method for estimating 3D space face pose was proposed based on affine transformation and linear regression. Namely, after tracking face feature points, a roughly estimated value was obtained based on affine transformation relationship, and then this rough value was taken as the starting value, precise value of face pose was obtained based on linear regression iteration. Finally, the experimental results show that the method achieves better estimation accuracy and robustness in a wide range of face poses.

Fast image interpolation algorithm based on edge-directed max-relativity

2006, 26(12):  2880-2883. 

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Better subjective quality and lower computational complexity of the algorithm are important in video and network signal processing. And the smooth effect and staircase of image details or edges are inevitable during conventional image interpolation. A new rapid image interpolation algorithm based on edge-directed max-relativity was proposed. The algorithm took account of the multiple directions relativity of local neighbors and made full use of six down-sampled neighbors involved in the low-resolution image to estimate relative information at high resolution. Experimental results demonstrate that the algorithm not only decreases the computational complexity but also substantially improves the visual quality of the interpolated images.

Algorithm for drawing the surface of equation

2006, 26(12):  2884-2886. 

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An algorithm which can draw any complex surfaces expressed by explicit equation or parametric equation was given. Firstly, the surface was dispersed into quadrangular meshes, then, the self-hidden lines were removed from the surface by the algorithm of removing hidden lines. In the algorithm of removing hidden lines, the conception of hiding-polygon was introduced. By judging whether the dispersed vertexes on the surface should be hidden or not, and getting the intersecting points between the potential hidden lines and the hiding-polygons, the actual hidden lines which were the parts of the potential hidden lines can be obtained. The experimental results have verified the effectiveness of the proposed algorithm, and it is generalizable to 3D objects displayed in meshes model.

Information security

Detection of stego images using one-class support vector machines with multiple hyperspheres

2006, 26(12):  2887-2889. 

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In order to reduce the complexity and weak generalization of classification method using two class support vector machines in images steganalysis, a new Kernel-based classification method using OC-SVMs with multiple hyperspheres was put forward. Considering that the data features were expected to be more separable in kernel space, we first performed the K-means clustering in kernel space, then trained the sub-class data separately using OC-SVMs and established a multiple hyperspheres classification model to decide the class label of new data. The experimental results show that this method has efficiently improved the classification precision.

Lossless data hiding using integer wavelet transform and threshold embedding technique

2006, 26(12):  2890-2893. 

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A new lossless data hiding method for digital images using integer wavelet transform and threshold embedding technique was proposed. Data were embedded into the Least Significant Bit-plane (LSB) of high frequency CDF (2,2) integer wavelet coefficients，which accorded with the principle of Human Visual System (HVS). Histogram modification was applied as a preprocessing to prevent overflow/underflow. Whether the data should be embedded into the coefficient or not was determined by a predefined threshold. Experimental results show that this scheme outperforms the prior arts in terms of a larger payload (at the same PSNR) or a higher PSNR (at the same payload).The method is successfully applied onto the CorelDraw which contains 1096 images in all.

Authentication mechanism and improvement of IEEE 802.1x protocol

2006, 26(12):  2894-2896. 

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Based on the analysis of the IEEE 802.1x authentication mechanism, to fetch up the flaws that IEEE 802.1x lacks source authenticity and integrity protection, an improved IEEE 802.1x authentication mechanism (AIP) was proposed. By adding a Protection part into EAPOL packets, this scheme can fetch up the flaws of IEEE 802.1x, such as intermediary attack and session hijack. Through the capability analysis, the scheme has more advantages as source authenticity and integrity protection than the original one.

Sybil attacks detecting in wireless sensor networks

2006, 26(12):  2897-2899. 

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To study Sybil attacks, a light-weight method to detect Sybil attacks was proposed. The method detected part of Sybil attacks through the transmission of packets between base station and nodes, formed multi-path, and defined query packets. Finally the fields in the query packets, which came to destination node from different routes, were compared. Also the method used multi-hop acknowledgement to generate alarm packets to detect the Sybil attacks. Different from some other methods that use encryption, identity certification and so on, this method reduces communication overhead and computations, and saves the energy of sensor nodes.

Trust-based hybrid P2P model

2006, 26(12):  2900-2902. 

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To improve the security performance of P2P networks, the hybrid P2P structure based on sticking point and the reputation-based trust mechanism was introduced，and a hybrid P2P model based on the reputation-based trust mechanism was proposed. Meanwhile, the workflow of the model was described. The model can effectively build up a high efficient and reliable trust relationship between peers, prevent malicious attack and enhance security and efficiency of the P2P networks.

Blind watermarking algorithm based on wavelet tree and chaotic scrambling

2006, 26(12):  2903-2905. 

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A new blind image watermarking algorithm based on the wavelet tree structure was proposed, which featured the following characteristics as scrambling the watermark to enhance the security, taking advantage of the human visual system properties and extracting the watermark without original image. The experimental results show that the proposed blind image watermarking scheme is invisible and robust against various signal processing attacks such as compression, noise adding, image enhancement, cropping and so on.

Design and implementation of discretionary access control policy with time character on Linux

2006, 26(12):  2906-2909. 

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Discretionary Access Control (DAC) policy is an access control based on ownership relations between subject and object. The subject can discretionarily decide that who, by which means, can access his owned objects. Regarding the system time as a basic security element, DAC_T (Discretionary Access Control Policy with Time Character) was proposed and formalized. DAC_T resolves the problem that the subject can discretionarily decide that who and when can access his owned objects. Finally, DAC_T was implemented on Linux, and a demo was obtained. It is proved that the demo can help subject realize the time constraint on object.

Design and analysis of secure payment protocol based on trusted third party

2006, 26(12):  2910-2912. 

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A payment protocol named Secure Electronic Transaction based on Trusted Third Party (SETTP) was proposed, in which both electronic and physical goods could be paid on line. A trusted third party which has the functions of confliction-arbitrate and data backup was constructed. A method of setting Payment Time Expire (PTE) during the process of bank payment was put forward to make sure the fairness to both parties of the transaction. Finally the characteristics of the SETTP protocol such as security, atomicity and fairness were analyzed.

Logs auditing and analysis system based on virtual monitor

2006, 26(12):  2913-2915. 

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SNARE is an audit logging and analysis tool for the Linux operating system. However, it is also vulnerable. A new approach was designed to protect SNARE from being tampered. With the capability of virtual machine monitor, SNARE was ported on two virtual machines running over the Xen which was a virtual machine monitor. The SNARE patch for Linux and audit daemon, which were two principal components of SNARE, were separated into two virtual machines isolated strongly by Xen. The mechanism for sharing memory between virtual machines was provided by Xen. By the mechanism, SNARE patch for Linux running on one virtual machine records and transfers the audit logs into the audit daemon running on another virtual machine. Compared with the traditional SNARE, the new method makes it is more difficult to destroy or tamper the audit logs. Preliminary evaluation shows that the prototype is simple and efficient.

Study and implementation of the intrusion detection model based on measurement module

2006, 26(12):  2916-2918. 

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Based on Trusted Computing concept and RBAC technology, this paper proposed a firmwarelevel intrusion detection model which challenged current PC architecture named measurement module and implemented the key steps.

Reversible certificate state management model for mobile Ad hoc networks

2006, 26(12):  2919-2921. 

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A new certificate state management model with reversible characteristic was proposed for certificate management policy in Mobile Ad hoc Networks (MANet). An algorithm was designed to compute the certificate credit with its history value and its transform factor quantitatively. According to its credit, a certificate state may experience the reversible process of suspending and reactivating instead of the one-way revocation, which denotes the variable trust relationship among the certificates. The analysis of the influence that the weight factor and individual node put on the computation result was provided with an example.

Blind robust watermarking schemes based on 3D mesh object

2006, 26(12):  2922-2923. 

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A new method for blind robust 3D mesh object watermarking applications was proposed. First, a transformation of the model to an affine invariant space was finished prior to watermark embedding. Then the Cartesian coordinates was converted to spherical coordinates in which the watermark was embedded. In affine invariant space, the 3D object is not affected by geometric transformations, such as translation, rotation and scaling. So the proposed method is robust enough to geometric transformations, which is proved by experimental results. The method is good at visual masking too.

Digital rights management system with equity anonymity

2006, 26(12):  2924-2927. 

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The current Digit Rights Management (DRM) systems only pay much attention to the security issue, but it does not take full account of the user's purchasing privacy. By utilizing the equity anonymity technology of the e-cash, we can improve the current DRM model and make the legal users have equal purchasing anonymity. Meanwhile the system can disclose the real identities of the illegal users.

New faster software implementation method of RSA algorithm

2006, 26(12):  2928-2930. 

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Based on introducing standard RSA crytsystem, we advanced an improved method of the software implementation of module power operation using approximate algorithm of calculation shortest addition chains, and improved decryption method of RSA on the basement of Mixed-Radix Conversion (MRC) which is to solve Chinese Remainder Theorem (CRT). Finally, combined with rapid effective prime testing method, a new algorithm that can rapid software implementation RSA cryptsystem was proposed, and it has also been analyzed and compared to other related algorithms. Experimental results show that operation velocity of encryption and decryption operation can be increased 6 to 10 times on average by using the new method.

Research into Agent-oriented worm defense system

2006, 26(12):  2931-2934. 

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Current situation of the traditional security defense system was briefly introduced. Considering the shortcomings of the current worm defense system and advantages of Agents, an Agent-oriented worm defense system named AOSWD was proposed, which can defend against Internet worms quickly and effectively．The architecture and the key technology of the system were discussed. Experimental results prove the effectiveness of AOSWD.

Application of trusted computing compliance in VPN

2006, 26(12):  2935-2937. 

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Virtual Private Network (VPN) was studied. VPN enables telecommunication, but it cannot authenticate the configuration of computers. If a computer used for VPN access was compromised, an attack could exploit it to gain unauthorized access and make endpoint insecure. When being connected to the corporate network, the computer becomes a distributor of the untrustworthy endpoint to other computers on the enterprise network. Trusted computing technology can be used to solve these problems.To guarantee the security and trustworthiness of the endpoints, network connection and communication,Trusted Platform Module (TPM) was used to bind keyed attestation to authenticate the integrity of VPN, and Trusted Network Connect (TNC) was used to authenticate the security of network connections.

Universal designated verifier signature (proof) schemes without random oracles

2006, 26(12):  2938-2940. 

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Based on the latest proposed k+1 assumption, two different schemes of universal designated verifier signature were proposed. Both of them are provably secure without random oracles. The second scheme, in which the holder can designate his/her signature to anyone he/she wants and an efficient interactive protocol is used to verify the designated signature, is usually called universal designated verifier signature proof scheme.

Design and implementation of file watching system based on mandatory access control

2006, 26(12):  2941-2944. 

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Bell-Lapadula model based on information confidentiality and Biba model based on information integrity were introduced. Then a new Mandatory Access Control （MAC） model based on the two modules above was designed. By using Windows NT file filter driver, a file watching system which adopted this new MAC model was developed, and the components and key technologies of it were given in detail. This file watching system has the advantages of protecting information confidentiality and integrity, and resisting the attacks from both local and remote users.

Research,improvement and implementation of RBAC model

2006, 26(12):  2945-2947. 

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An improved model was proposed for the deficiencies of traditional RBAC model in rolemanagement such as over complexity and rough granularity. The characteristics of this model were described in detail, in which permission constraint elements and special permissions were introduced. Acting as permission data, other functional modules and their related operations can make the couple of the permission codes and operation logics eliminated. As a conclusion, implementation of this improved model in system of permission management was described in detail, also including its advantages and disadvantages.

Database Technology

Grey particle swarm algorithm for multi-objective optimization problems

2006, 26(12):  2950-2952. 

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Since the basic particle swarm algorithm cannot solve the problem of high-dimension objective optimization, a Grey Particle Swarm Optimization (GPSO) algorithm for high-dimension objective optimization was proposed. This method can analyze the degree of approach between objective vectors. And the panorama of the solution space can be controlled by this way. The global maximum and individual maximum in the particle swarm algorithm can be selected according to the degree of grey relevancy. Test results show that GPSO is feasible and effective, and it extends the application field of particle swarm algorithm.

Cluster analysis based on cultural algorithms

2006, 26(12):  2953-2955. 

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After analyzing the disadvantages of the classical K-means clustering algorithm，a new clustering algorithm based on cultural algorithms was proposed, and two different versions of implementations named CA-version1 and CA-version2 were put forward. CA-version1 uses situational knowledge to control the direction of mutation, and uses normative knowledge to control the step size of mutation. CA-version2 uses normative knowledge to control the step size and the direction of mutation. Cultural algorithms are dual inheritance systems which are different from the others. Because of this feature, the search process is guided by using knowledge abstained from the process of solving problem, which can produce substantial performance improvements. Compared with the classical K-means clustering algorithm, the algorithms based on cultural algorithms, proved by the experimental results, can not only avoid the disadvantages of the classical K-means clustering algorithm, but also have greater searching capability globally than genetic clustering algorithm. Besides, it shows that CA-version2 is more suitable than CA-version1 for clustering problem.

Multi-peaks function optimization using quantum-behaved particle swarm optimization

2006, 26(12):  2956-2960. 

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An improved Quantum－behaved Particle Swarm Optimization (QPSO) for multi－peaks functions optimization was proposed. In the proposed Species-based QPSO (SQPSO), the swarm population was divided into subpopulations in parallel based on their similarity. Each subpopulation was set around a dominating particle called the species seed. Over successive iterations, species were able to simultaneously optimize towards multiple optima by using QPSO, so each peaks were ensure to be searched equally, no matter whether they are global or local optima. Experimental results demonstrate that SQPSO can search as many peaks of function as possible. Simulation results show the convergence performance of SQPSO is superior to that of PSO.

Attribute reduction based on partition in information system

2006, 26(12):  2961-2963. 

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Based on the viewpoint that attributes have different partition ability, left-partition and right-partition of the attributes were proposed. Characteristics and properties of them were investigated. The judgment method of core attribute was given in regard to the attribute partition view. A new attribute reduction algorithm named ARABP based on attribute partition was brought forward, and the validity of the algorithm was illustrated by theoretical analysis and experimental results.

Research into information retrieval based on the combination of keyword and semantic concept

2006, 26(12):  2964-2966. 

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After analyzing the principle of keywords and concept retrieval，a new vector space model named SC-VSM based on the semantic concept retrieval was proposed. Meanwhile, based on the combination of SC-VSM and keywords retrieval, an approach was presented in which the combination parameters can be adjusted according to different domains in order to obtain the best information retrieval result. Experimental results show that the SC-VSM is superior to the VSM，the combinative approach can not only reserve the advantages of keywords retrieval and concept retrieval, but also compensate for their shortcomings.

Study on the application of context reasoning based persistent ontology

2006, 26(12):  2967-2970. 

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The definition of Ontology and its descriptive language, and OSGi service gateway model and its framework were introduced at first, and then a concept of Intelligent Residential Gateway(IRG) based on Ontology and its infrastructure were put forward, its principle and the context Ontology were described. The IRG uses the inference interface of Jena, a semantic Web framework, to implement the inference of the context ontology. Finally, there is an example to demonstrate the reasoning process.

Research of simulating recognition of Chinese characters by Bidirectional SOFM

2006, 26(12):  2971-2973. 

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Word superiority effect and word inferiority effect are invovled in recognition of Chinese characters. The former one means that the recognition of holistic character unit is better than that of radical unit and the latter contrarily. In this paper, bidirectional SOFM was proposed based on Self-Organization Feature Map Algorithm, accomplishing clustering of Chinese characters and their radical unit, establishing the connection between the two nets. Through bidirectional test, diversity constructional Chinese characters have their own effects, and SOFM is used in a new perspective. The result is helpful to Chinese characters teaching.

Modeling and simulation for stochastic inventory system based on synthesis coefficient

2006, 26(12):  2974-2976. 

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Stochastic inventory system of (s,S) Policy, of which both the demanded quantity and time between demands are random variables, was discussed. Taking stock total cost and rate of shortage as two performance indexes of the system, simulation model was created. The two indexes weighted average, synthesis coefficient was given. Simulation motion graph was designed. When various cost parameters were given, the optimal policy could be selected with computer simulation technique and synthesis coefficient.

Survey on semantic cache in native XML databases

2006, 26(12):  2977-2981. 

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The concepts of semantic cache and XML inquiry language were introduced,and a thorough survey and detailed analysis of implementations and technical characteristics of the existing semantic caches in native XML databases were presented. A new fast semantic cache look up algorithm was proposed. New problems and challenges arising from current research were discussed and some suggestions were proposed for future work.

Dissimilarity measure based on parameterfree data mining

2006, 26(12):  2982-2984. 

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There are many cases of getting fault results in data mining because of setting parameters. Therefore, parameterfree data mining appeared in order to resolve the problem. A new Compression-Based Dissimilarity Measure which was based on Kolmogorov complexity theory was proposed. Because compression algorithms are typically space and time efficient, the method based on it also has good performance. Applying it to hierarchical clustering can get good result.

Discovery of asynchronous periodic patterns with multiple granularities

2006, 26(12):  2985-2987. 

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An algorithm for efficient mining of asynchronous periodic patterns with multiple granularities by exploring some interesting properties related to asynchronous periodicity was proposed. The algorithm generated all valid time section at first, and then found the longest valid time segment by using valid time section. The performance study shows that the proposed method is stable and efficient.

Efficient learning algorithm for Fuzzy bi-directional associative memory based on Lukasiewicz's t-Norm

2006, 26(12):  2988-2990. 

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Taking advantage of the concomitant implication operator of TL, which is a t-norm, a simple efficient learning algorithm was proposed for the fuzzy bi－directional associative memory based on fuzzy composition of Max and TL(Max－TLFBAM). It is proved theoretically that, if there is a connected weight matrix which make arbitrarily given pattern pairs set become stability state set of Max－TLFBAM, then the proposed learning algorithm can find the maximum of all connected weight matrices. An experiment was given to test the effectiveness of the presented learning algorithm.

XML query solution based on editing distance

2006, 26(12):  2991-2993. 

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Based on editing distance, a new XML query solution was proposed. To reduce the searching time, this solution performed content query before schemas query. Furthermore， M aggregation was introduced in schemas query, XML documents were ranked by the editing distance between the M aggregation of querying tree and the M aggregation of simplified DTD, which improved the precision while maintaining a high level recall.

Typical applications

Design and implementation of distributed file buffer system based on synchronization engine

2006, 26(12):  2994-2997. 

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With regard to the network bandwidth and efficiency problem of centralized data management, a distributed file buffer system based on synchronization engine was brought forward. Considering distributed deployment and efficient delivery of frequently updated files between center and large numbers of branch, the system separated file synchronization function into three key components: synchronization engine, file transmission service and synchronization console. Two-year running has shown that the proposed system can deliver reliable and effective file synchronization service.

DNA algorithm of graph vertex coloring problem based on sticker model

Yu-Xing YANG

2006, 26(12):  2998-3000. 

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In order to solve the graph vertex-coloring problem, a DNA algorithm based on sticker model was proposed, which converted the coloring problem to satisfiability problem on the basis of the vast parallelism. The operation steps were given through an instance. And a simulation experiment was carried out to illustrate the biochemical procedures. The final coloring schemes were got. Consequently, the feasibility of the algorithm is proved.

Independent tasks scheduling algorithm based on dynamic fit degree

2006, 26(12):  3001-3003. 

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After analyzing the advantages and disadvantages of the scheduling heuristics in the literature, in order to get better load balance and schedule more tasks to its more suitable machines at the same time, a new scheduling algorithm based on Dynamic Fit Degree (DFD) was put forward. The suitability of the machine with minimum time for finishing the task was described by task's DFD schema. The proposed algorithm used DFD as the priority, and the task with biggest DFD was scheduled first in each step. The simulation results compared with other scheduling algorithms show that the proposed algorithm produces better results.

Mechanism of persistent naming topological entity supporting collaborative CAD

2006, 26(12):  3004-3007. 

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Direct referring to topological entity of B-Rep domain in feature's parametric definition domain is inherent limitation of previous persistent naming topological entity method. Therefore, a feature-based solution for topological entity naming was proposed. Firstly, uniform naming method for feature face was established and its name remained invariable during the modeling procedure. Secondly, the expression between topological entity and feature face was established and topological entity expressed by feature face was referred to during the course of feature's parametric definition, and as a result, the problem of persistent naming topological entity for feature-based collaborative CAD was solved. Thirdly, the concept of reference face was proposed and utilized to solve ambiguous referring problem, which arose from topological face splitting, topological edge splitting and multiply intersection edges. Based on the above mentioned, topological face and topological edge matching method was discussed in detail.

Raw material configuration by multi-agent negotiation

2006, 26(12):  3008-3011. 

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A market-mechanism-based multi-agent negotiation model was put forward. As a mediator, the market Agent summarizes the individual information of each Agent, and then returns the summarized result to them. Each Agent is assumed to compute its best demand by programming algorithm to maximize its utility. The paper gave the pricing algorithm and the allocation algorithm. The simulation results prove this model is better than initial allocation solution.

Focused crawling method based on improved C4.5 exploiting anchor text

2006, 26(12):  3012-3014. 

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A new focused crawling method based on anchor text and improved C4.5 decision tree algorithm was proposed. It exploited the anchor text of URL to train the decision tree, and then applied the decision tree model to decide whether a downloaded page was on topic and how to choose the next URL to visit. Finally, a prototype system named DTFC based on this method was implemented, and experiments in four university websites were carried out in allusion to "academic report". The experimental results show that DTFC outperforms two standard crawlers for focused crawling.

Study on layout problem using quantum-behaved particle swarm optimization algorithm

2006, 26(12):  3015-3018. 

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QuantumBehaved Particle Swarm Optimization (QPSO) was applied to layout problem of two-dimensional irregular polygons based on the Heuristic Bottom-Left (HBL) algorithmof polygons scan conversion method. The layout particles were constructed, and the processes of layout optimization using QPSO and Simulated Annealing Genetic Algorithms (SAGA) were given. By comparing QPSO to SAGA in layout optimization, experimental results show that QPSO is a kind of more efficient optimization algorithm for layout problem.

Study on hash-tree searching anti-collision algorithm

2006, 26(12):  3019-3022. 

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A new anti-collision algorithm based on hash-tree searching was proposed, and three principles that the algorithm follows were formulated, the procedure of the algorithm was introduced in detail. The performance of this anti-collision algorithm was compared with EDFSA algorithm's in system efficiency and identification time. An evaluative model for the system efficiency was put forward, and then the system efficiency expectation of the proposed algorithm was proved between 36.8% and 1, which was better than that of EDFSA algorithm. The emulation results show that the identification time of the proposed algorithm is less than that of EDFSA algorithm when identifying lots of tags. In addition, the algorithm does not require testing the precise location of collision bits, so it is more flexible than the anti-collision algorithm based on binary-tree searching. The proposed algorithm has raised system efficiency, and has more extensive application prospects in auto identification field.

Application of dominance rough set in seismology

2006, 26(12):  3023-3026. 

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In seismology, rough set can be used in the reduction of attributes. But classical rough set are based on indiscernibility relation or similarity relation. The problems in Seismology deal with ordering objects instead of classifying objects. Now we presented an extension of the classical rough set called dominance-based rough set, and an attributereduction algorithm based on dominance matrix. The experiment indicates that the results will be more meaningful than those induced by the classical rough set theory.

Research and application of data mining algorithm on technical-tactics analysis of volleyball matches

2006, 26(12):  3027-3029. 

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The difficulty of applying data mining technology to the technical-tactics analysis in sports field was investigated and a solution to mining the key factor of scoring in volleyball matches was presented. This solution applied an approach of data mining based on Markov process to find focal process of action transitions by calculating system reliability difference. Because rules of volleyball match brought ambiguity to data, a solution was proposed which preprocessed the data respectively by setting the threshold of the state transition probability. The experiment proves the correctness and feasibility of the solution.

Concept based algorithm of dealing near-replicas of documents on the Web

2006, 26(12):  3030-3032. 

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To solve near-replicas of documents on the Web obtained by search engine, a similarity dealing algorithm was proposed. Based on concepts extracted from the Web pages and inverted file, the algorithm built a model which shrank the scale of the Web pages processed. The algorithm saved a great deal of temporal and spatial resources and provides a good foundation for near-replicas detection.

Research of dynamic workflow supporting multiple instances pattern

2006, 26(12):  3033-3036. 

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To express dynamic semantic of multiple instances pattern of workflow, a XPDL-based modeling approach was presented through analyzing the pattern. Meanwhile, the design of corresponsive component in workflow engine was given, and it was implemented in an open source workflow engine: Enhydra Shark. In this component, the design of "Activity Instances Manager" solved the dynamic execution and data sharing problem of instances. Running of the engine proves that this solution can support the multiple instances pattern efficiently, and improve the dynamic of workflow model.

New method of printing multitoning image with large format bilevel printer

2006, 26(12):  3037-3038. 

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In order to print multitoning image with large format bilevel inkjet printer, a new method based on the technique of green noise was proposed. Multiscale error diffusion method was designed by the technique of threshold modulation, and then the false contouring of the output was removed. The experimental results show that the multitoning image got is favorable.

Field environment modeling and dynamic path planning

2006, 26(12):  3039-3042. 

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Facing to the problem of navigation and control of mobile robot in field environment, an approach to environment modeling and dynamic path planning in field environment was proposed. Given the Digital Elevation Model (DEM) of the terrain, this method can model the field environment effectively and synthetically considering the factors such as the capability restriction of robot and the characters of terrain and so on. Based on the environment modeling, the path planning, which adopted a method that combined global information with local information and integrated pre-action planning result with online planning, can satisfy the requirement of the dynamic path planning in filed environment. The experimental results show that this method can fit in with different complicated field environments very well.

Research into the extensible expert control system based on VBA

2006, 26(12):  3043-3046. 

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One of the key problems of traditional expert control system is that it is not flexible enough for users to define the process implementation online. To solve the problem, a new extensible expert control system was presented. It integrated VBA (Visual Basic for Application) with traditional expert control system. In the system, users can define the process object as VBA object model, and then define its fire operation in the integrated development environment supplied by VBA, while the implementation of the fire operation is usually fired by the message the process sends, so the process object's behavior can be changed with the condition. Furthermore, while defining the method, numerical computation can be imported to enhance the calculating performance. At last, the results of a simulation experiment show that this kind of control system will more flexibly control the process.

Approach to naming and identifying topological entities

2006, 26(12):  3047-3050. 

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An approach to naming and identifying the topological entities was proposed, based on which a data structure named Topological Relation Graph (TRG) was introduced .TRG memorizes the solid process of a part and tracks the topological relation of entities between original and current solid part. Using TRG, solid modeling system can reevaluate part correctly according to the original designer's intent. Algorithms for identifying the solid face, edge and vertex were also given in this paper. The proposed approach can track the modeling history correctly, represent designer's intent of original solid part, also can identify the solid element including solid face, edge and vertex.