Journal of Computer Applications

Research on the time-dimain security of BLP model

LIN Hong-gang，DAI Zong-kun,LI Huan-zhou

2005, 25(12): 2723-2724.

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Based on a thorough research on the time-domain security of BLP(Bell-LaPadula) model,an incorrect understanding on the time-domain security of BLP model was pointed out,and a new theoretical proof about the time-domain security of BLP model was given.The BLP model accords well with the requirement of confidentiality was indicated.

Prevention against differential power analysis attacks based on masking

ZHOU Wen-jin,FAN Ming-yu

2005, 25(12): 2725-2726.

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An efficient way calling masking to prevent DPA(Differential Power Analysis) attacks was introduced,and the modified simple fixed-value masking method was spreaded to fixed-value masking method to prevent SODPA(Second-order Differential Power Analysis).

Group key management strategy of mobile Ad Hoc network

ZHANG Zhen-ping,XU Li,YE A-yong

2005, 25(12): 2727-2730.

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Mobile Ad Hoc network is a collection of wireless mobile nodes forming a temporary computer communication network without the aid of any established infrastructure,and one of the challenges in designing the kind of network is the frangibility in withstanding the attacks of security.The group key management of mobile Ad Hoc network is facing a great challenge because of its acebtric,dynamic topology and realtime changed link.By comparing and analyzing the strategy of group key management in existence,it provides an idea of the further study in this field.

Implementing access policies with hidden credentials

HONG Fan,LIU Lei

2005, 25(12): 2731-2733.

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To solve the efficiency problem of useing hidden credentials in trustmanagement system,a scheme using hidden credentials to efficiently implement complex polices with "polices expression" and "final prefix" was presented.The encryption and decipherment times were reduced by constructing and simplifying policy expression,the information restore was guaranteed by useing "final prefix".Example shows that the scheme is feasible and efficiency.

Design of intrusion detection system in high-speed networks based on data distribution

MAN Hong-fang

2005, 25(12): 2734-2735.

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A method of distribute data was proposed to improve the detection performance of system in high-speed network.The network traffic was divided to several parts and transferred to different devices.The experiment approved its effectiveness.

Multiple adaptive digital watermarking method based on chaos and independent component analysis

LU Ji-wen,ZHANG Er-hu

2005, 25(12): 2736-2738.

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Based on chaotic sequences and independent component analysis(ICA),a novel multilevel image watermarking method was proposed in wavelet domain.Firstly,discrete wavelet transform(DWT) was applied to one subimage extracted from the original image according to one chaotic sequence label and multiple independent chaotic watermark signals were generated and embedded into the middle wavelet frequency coefficients adaptively.The watermarking was detected according to the Newman-Pearson criterion without the original image.Then ICA was applied to extract the watermarking if the watermarking are the original watermarking.Situational results demonstrate that this algorithm is an effective digital watermarking method with very outstanding robustness against many common attacks such as noise attacks,geometric operations and JPEG compression,and it solves the problems of multi-copyright claim in digital products.

Analyses and research of the program behavior in computer system

ZHU Guo-qiang,LIU Zhen,LI Zong-bo

2005, 25(12): 2739-2741.

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Three methods of distillation in the program behavior were introduced,and the program behavior was distilled and analyzed in LKM.The system call arguments was anlalyzed from the length distribution of character string,characteristic distribution of character string and special system call arguments,which rich the technique to analyze the program behavior and improve the exactness of detection of program anomalism.

Using dual chain hash table to improve performance of NP firewa

ZHANG Guo-bing,ZENG Wu,HUANG Hao

2005, 25(12): 2742-2744.

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Too many memory accesses slow down the process of high-speed data streams in NP-based firewalls significantly.Hash table is one of the most important data structures in firewall designing.The average memory access is in direct proportion to the length of chain if we resolve hash collision with separate chaining.To divide one chain into a pair can improve system performance by reducing total number of memory access.A method to handle hash collision with dual chain was introduced,and its affection on performance was analyzed,The design and implementation was given based on network processor IXP2400.

Analysis and realization of anti-DDoS attack algorithm based on the SYN Cookie mechanism

SHEN Qing,JIN Xin-yu,ZHOU Qi-min

2005, 25(12): 2745-2747.

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The principle of DDoS(Distributed Denial of Service) useing the limitation of TCP/IP was introduced.Based on the monitor on the network packet traffic and the useage of the system resource,a method that leads the RSA algorithm into the SYN Cookie mechanism to encrypt and filtrate the IP packets was proposed,which can detect and reduce the damage of DDoS.The method have maken a good performance in the experimentation.

Research on classification technology of networks attacks based on NIDS date source

WANG Yu-fei,ZHANG Ji-wen,GU Jian

2005, 25(12): 2748-2750.

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A method of network attack classification was presented.The method was based on the NIDS(Network Intrusion Detection System)data source and integrated with the technique of network protocol analysis.Finally,the method was formally descriibed and demonstated using Z language.

DDoS flood attacks detection based on fuzzy theory

ZHANG Yan-bo,LI Ming

2005, 25(12): 2751-2752.

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To resolve the problem of detecting Distributed Denial of Service(DDoS) attacks, a dynamic threshold detection method based on fuzzy logic was proposed.Through fuzzy compound operation analysis and according to nearest neighbor principle,a decision was got,which is the attack level(trust degree) of detected packet.Web security masters can make responses betimes according to the result,and the responses can save furthest the loss under real time attacks.

Text zero-watermarking algorithm based on chaotic mapping

CHENG Yu-zhu,SUN Xing-ming,HUANG Hua-jun

2005, 25(12): 2753-2754.

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A novel text zero-watermarking algorithm based on chaotic mapping was brought forward.The features of presented method are as follows: First,there are no modifications to the text document among the process of watermarking embedding,thus the watermarking is perceptually invisible.Second,the watermarking is robust against copying,cutting and formatted modifying.Third,the watermarking can be detected only by using a secret key and doesn’t need the original text.

Design and implementation of key distribution system based on SNMPv3

CHEN Yue,ZHOU Ming-tian

2005, 25(12): 2755-2758.

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The new security mechanism and the notification mechanism of SNMPv3 were introduced.Then how to combine network management systems and key distribution systems was studied,and a key distribution system based on SNMPv3 was designed.

Improved algorithm for relational data watermarking

BAO Xi-ri-mo,ZHANG Jing,LI Jun-huai,ZHANG Jie

2005, 25(12): 2759-2762.

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Agrawal algorithm was introduced,which was easy to destroy data usability and sensitive to attributes ordering,an improved algorithm based on the improvement strategies of introducing percentage constraint and sorting attributes according to their cryptographic keyed hash values was presented.Deployments of the original and improved algorithm on real-life data show that the improved algorithm is able to preserve data usability more effectively, robust against attributes reordering attack,and it is a complete blind and more practical system.

Interaction technology with firewalls and intusion detection system

FENG Qing-yu

2005, 25(12): 2763-2764.

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Considering the demand of obtaining integrity and dynamics in network security,an interaction model with firewalls and IDSs(Intrusion Detection System) was implemented based on the ideal of distributed open platform of security.To strengthen the stop function of intrusion detection,the idea which interaction system making initiative recovery to paroxysmal network attack was presented,and the key technology of implementation was introduced.

ABAC model based on XACML in Web Service

SHEN Hai-bo,HONG Fan

2005, 25(12): 2765-2767.

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The XACML(eXtensible Access Control Markup Language) was analyzed,and an ABAC(Attribute-Based Access Control) model based on XACML in Web Service was presented.The model adopted the authorization mechanism based on user,resource and environment attributes,but not user identity.This mechanism can resolve administrative scalability problem and provide fine-grained access control for Web services,and it is fit for highly dynamic and distributed environment in Web services.

Group key distributed algorithm based on role authorization in Ad Hoc network

XU Guang-we,HUO Jia-zhen,XU Guang-yuan,Cao Qi-ying

2005, 25(12): 2768-2769.

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Ability of resisting authorization assault is weak for existed group key distributed scheme.A group key distributed algorithm based on role authorization was proposed.The algorithm improves ability of resist and depresses threat of security on authorization assault by importing role authorization restricted in access control for group.Comparing with the other alike schemes,the proposed scheme is secure and useable.

Research and improvement of certificate revocation mechanism in PKI

XU Cheng-qiang,ZHU Fang-jin,SHI Qing-hua

2005, 25(12): 2770-2771.

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To decrease the storage space and improve the search velocity of CRL(Certificate Revocation List),a bit pointer was used to shorten the certificate number of it.And a new certificate recocation tree was proposed,which could keep the good properties of CRT(Certificate Revocation Tree) that is easy to check or prove whether a certificate is revoked or not,the check only need the related path values but not the whole CRT values.The new tree also could overcome the disadvantage of CRT that any update will cause the whole CRT to be computed,so it accelerate the speed of the CRT update.

Accelerating implementation of IKEv2 by using security coprocessor

ZHANG Ling-ling,PAN Xue-zeng,CUI Yu-zeng

2005, 25(12): 2772-2773.

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Comparing the difference between IKEv2 and IKE,the advantages of IKEv2 on the complex of the implementation and the low delay were analyzed.The message exchange and the generation of various keys of IKEv2 was introduced, an implementation approach of IKEv2 using the security coprocessor were proposed.This implementation can accelerate the process of key generation,message encryption and integrity verify check.

Intellectualized diagnosis model for the missile fault based on artificial immune system

GUO Xiao-sheng,YANG Jian-hua

2005, 25(12): 2774-2776.

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A conception of missile intelligent fault diagnosis technology based on artificial immune system was presented,the fault diagnosis cell model and the fault diagnosis gene model were analyzed.How to create and evolve the fault diagnosis gene model was introduced,and the intelligent fault diagnosis principle based on artificial immune system was discussed.

Application of BP neural network based on genetic algorithm

PAN Hao,WANG Xiao-Yong,CHEN Qiong,HUANG Shao-luan

2005, 25(12): 2777-2779.

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Aiming the insufficiency of BP neural network,a new neural network based on genetic algorithm was presented.The algorithm made fully use of BP network’s local searching and GA’s global searching,improved the convergent rate and convergent precision.The algorithm was supplied to neural network’s training of dynamic weighing system.The results show that the algorithm is effective.

Study on Chinese keyword extraction algorithm based on Naive Bayes model推

CHENG Lan-lan,HE Pi-lian,SUN Yue-heng

2005, 25(12): 2780-2782.

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A keyword extraction algorithm for Chinese documents based on Na ve Bayes model was proposed,which involved training and testing process.Parameters of the model were first obtained during training process,and then the probability of a word to be a keyword was computed based on the model during testing process.Experiment results show that the algorithm can extract more accurate keywords from a small scale document collection compared with traditional approach of if*idf.Moreover,it can flexibly extend feature items that indicate the importance of words,so it has a good scalability.

Application of a novel GEP algorithm in evolutionary modeling and forecasting

LU Xin-wei,CAI Zhi-hua

2005, 25(12): 2783-2786.

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To improve the veracity of forecasting,a hybrid GEP algorithm was presented,which combined GEP based on mutation operator and evolutionary algorithm based on colony-search strategy.The new GEP algorithm was applied to establish models with testing data.The applications show that the models set up by the new GEP algorithm are superior to the models set up by GP and simple GEP.The new algorithm has high-blooded forecasting accuracy.

Research on information grid management model based on generalized artificial life

SHEN Ji-quan,ZHENG Xue-feng,TU Xu-yan

2005, 25(12): 2787-2788.

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Humanoid information grid management model(HIGMM) based on generalized artificial life was proposed after researching the principle and approaches of generalized artificial life and information grid.The design idea of information grid management model with such humanoid management characteristics as dual management scheme,central-decentralized management pattern and multi-level coordination function was discussed.

Study on improving the convergence of genetic neural networks

LI Xiang-mei,ZHAO Tian-yun

2005, 25(12): 2789-2791.

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To describe the advantage and shortcoming of gradient descent algorithm and genetic algorithm for training connection weights of neural networks,a new algorithm combined genetic algorithm with gradient descent algorithm was proposed,referred as to Hybrid Intelligence learning algorithm(HI).Applied to the problem of optimizing the connection weight of the feedforward neural networks,the algorithm was feasible.The design and realization of HI was introduced.And it was proved that hybrid intelligence learning algorithm is better,faster and more accurate than gradient descent algorithm and genetic algorithm in theory and practice.

Clustering algorithm based on the MIBC decision-tree for CSR

CHEN Guo-ping,DU Li-min,FU Yue-wen,WANG Jin-lin

2005, 25(12): 2792-2794.

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An algorithm based on Minimum Bayesian Information Criterion(MBIC) was proposed to help optimize the node-splitting degree in a decision tree.First,it was proved in theory that MBIC can find a good balance between the complexity of model parameters and the scale of the training sets.Then,a formula was proposed to describe MBIC decision tree splitting and stopping criterion.Finally,the experiment on Chinese all-syllable recognition shows that MBIC has much better adaptive ability to variable acoustic model parameters and training sets than the classical Maximum Likeihood Criterion method.

Application of on-line filler modeling in specific domain speech recognition system

XING Lu-lu,XIE Sha-sha,SUN Jia-song,WANG Zuo-ying

2005, 25(12): 2795-2797.

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It is difficult for a speech recognition system in specific domain to deal with parentheses or sentence particles which is not depicted in rule since it instructs acoustic layer recognition in strict syntax rules model.To solve this problem,an on-line filler modeling method based on wordgraph decoder was applied to specific domain speech recognition system.The choice of the parameter N in this method was discussed in detail,and the correlation between materials’ SNR and the parameter N was also analyzed and validated.Moreover,a model parameter optimization method,which benefits from the correlation,was proposed.Computer simulation validates that the proposed method increases recognition rate by 18.34% for sentence and 11.47% for slot relatively.

Optimization of H.264 encoder based on SIMD technology

ZHU Lin,FENG Yan

2005, 25(12): 2798-2799.

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The SIMD（Single-Instruction Multiple-Data） instruction system was introduced,and further Integer DCT（Discrete Cosine Transform）,quant,interpolation and motion estimation of H.264 were optimized with the SIMD technology.The experiment indicates that the encoding speed of program after optimization reaches about 30fps and the speed has been improved by 68 times.

New frame-layer rate control algorithm based on H.264/AVC

WANG Zhao-shun,ZHANG Ping

2005, 25(12): 2800-2802.

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Rate control algorithm(JVT-H017) has been given in encoder reference software JM(Joint Model) 8.4.However,in JM a linear model is used to predict the MAD,which costs too much operations and exists deviations.A new frame-layer non-linear quantization parameter calculation model was proposed.Simulation results show that,comparing with JVT-H017,the H.264 coder using the proposed algorithm can control the bit rate more accurately and obtain a higher PSNR and visual quality.Especially when the two schemes are applied to the sequence with scene changes,no buffer overflow or underflow is guaranteed.

Video vehicle detection method based on texture analysis

XING Xiao-fei,LI Yong-ning,LIN Mu-hua

2005, 25(12): 2803-2804.

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Based on the working principle of virtual loops,texture analysis technology was applied to video vehicle detection.with the vehicle detection algorithm that using texture descriptor based on pixel-gray differences and dynamic threshold filter,a method of generating video trigger signals was presented.the specific algorithm of computing texture descriptor and updating threshold was designed.The experiment shows that it is effective.

Design and implementation of DRM system for streaming media

WANG Quan-wen,XIANG Wen

2005, 25(12): 2805-2807.

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To the current situation of streaming media DRM,a streaming media DRM system based on the three-layer architecture of key was presented.The whole system model was introduced and its security was discussed,and then implementation of the system was described in detail.

Improving hyper-granularity immingling technique: instruction set alternation technology based on thin virtual machine

YU Miao,SUN Qiang

2005, 25(12): 2808-2810.

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The hyper-granularity immingling technology is inefficent with small decrypted programs,then instruction set alternation technology based on a thin virtual machine was proposed.This technology employed an automata to record encrypt and decrypt ways.Furthermore,the thin virtual machine was responsible for interpretation and execution of these encrypted programs.Test results show that t
he technology can improve encrypted programs’ efficiency without weaken the security.

Modeling security software architecture based on process algebra

GAN Hou-yong,WU Guo-qing,HU Yong-tao

2005, 25(12): 2811-2813.

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On the basis of analyzing the security of software architecture model based on process algebra,compatibility check and interoperability check were extended from single software architectures to architectural styles,and software architecture description language was expanded.Software architecture can be modeled not only through a family of sequential process algebras terms,but also through an invocation of a previously defined architectural type.This method was introduced through an example.

Research on adaptive buffering management of DBMS based on access patterns

BAI Luo,WANG Yuan-zhen

2005, 25(12): 2814-2816.

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The status of buffer managing methods and the characteristics of the representative workload of DBMS was introduced.By analyzing access patterns,a model of evaluating cost was constructed,and its efficiency under various workloads was validated.The tests show that the adaptive policies based on access patterns of buffering management can get the optimal performance of DBMS.

Application of Java data persistence with Hibernate and Struts framework

GAO Ang,WEI Wen-xue

2005, 25(12): 2817-2819.

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To solve the problems such as poor expansibility and difficult work division in building Web application,a best practice of how to combine and deploy Hibernate and Struts framework to build high performance object/ relational persistence and MVC structure was provided.The combination of using them could construct a standard J2EE Web application and also improve the development efficiency greatly.

Study on a high reliable distributed virtual storage system

CAO Nan,KANG Mu-ning

2005, 25(12): 2820-2823.

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Aiming at the security and stability problems in distribute storage,a new distributed storage solution called RayStorage system was presented,and the main notion about "Distributed Visual Storage Architecture"(DVSA) which is the kernel of the ReyStorage System was discussed,and the basic concepts of storage pattern and the results of their efficiency analysis was given out.

DSP implementation of H.264 high performance video encoder

LU Bao-sheng,CHEN Qi-mei

2005, 25(12): 2824-2826.

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The design and implementation of H.264 hign performance video encoder based on TMS320DM642 DSP platform was described.The design of the hardware was introduced firstly,including the choice of DM642 DSP.Then,the encoder program was ported,and some algorithms focused on sample interpolation and motion estimation were optimized based on the custom operations of DM642.Experiment results show that the real-time H.264 encoder can be realized on DM642 by using proposed algorithms,while the high compression efficiency and image quality are preserved.

Image restoration based on least-squares increment iterative and regularization method

MIAO Qing,TANG Bin-bing,ZHOU Hai-yin

2005, 25(12): 2827-2829.

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Aiming at the restoration of blurred image,an effective restoration approach based on least-square algorithm was proposed.This method adopted increment iterative algorithm to improve convergence and meanwhile applied regularization technique to overcome ill-posed problem.In the computations,the equation was solved by steepest descend algorithm,and the complexity was reduced by FFT principal,meanwhile,the regularization parameter has its adaptive character,which can be determined in terms of the restored image at each iteration step therefore automatically correct to the appropriate value.Computer simulations show that the proposed method can properly retrieve the main information of original image,and the PSNR(peak signal to noise ratio) and subjective visual effect of the restored image are improved significantly.

SAR image segmentation based on multi-scale Markov random field

ZHANG Hong-lei,SONG Jian-she,ZHANG Xian-wei,QI Hai-long

2005, 25(12): 2830-2831.

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The multi-scale edge information was detected by useing module maxima of wavelet-transform.Edge position could be precisely localized due to the conception of clique introduced to MRF model.Then the SAR image was devided by useing Markov Random Field(MRF) model.Experiment results indicate that the method can improve the quality of image segmentation.

Second generation wavelet transform and its application in image fusion

LAN Wei,LIU Yu-shu,DU Zhi-qi

2005, 25(12): 2832-2833.

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A novel method of the second generation wavelet transform was introduced,which is to achieve wavelet transform by split,predict and update.Then it was used in image fusion successfully.The Experiment results show that the method is reasonable and effectual.

Image registration based on mutual information using steerable pyramid

HE Qing

2005, 25(12): 2834-2836.

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Using steerablity of the steerable pyramid,the orientation of the image could be obtained to search the best rotation transform,meanwhile the amount of translation could be searched together so that the method could deal with registration of both rotation and translation.Mutual information was used for similarity metric.Experiment results show that this approach performs well.

Application of lifting M-channels wavelet transform in image compression

LIN Zhen-xian,XUE Wen,SONG Guo-xiang

2005, 25(12): 2837-2839.

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According to the characteristic of the frequency domain being subdivided by the M-channels wavelet transform,the lefting decomposition of M-channels wavelet transform was carried out via the lifting scheme.That lefting decomposition is not exclusive,so that the transform is possessed the needed property by it.And a new algorithm of M-channels fast lifting wavelet transform was presented.The composed algorithm was given as long as the decomposed algorithm was given.Furthermore,wavelet transform from integer to integer could be achieved when the operation result was taken to the proximal integer.An application example and its simulations indicate that the algorithm is effective for image compression.

Image compression for region of interest based on relative multifractal spectrum

LI Hui-fang,XU Rui-ping,PANG Wen-jun

2005, 25(12): 2840-2842.

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The conception of the relative multifractal spectrum was introduced.Useing the relative multifractal spectrum,a new objective measure of image quality corresponding to the human visual impression was developed.An approach to identify regions of complexity disparity,as Region of Interest(ROI),in an image was presented based on the relative multifractal spectrum objective measure.A study of the effect of enhancing regions has been implemented.Later,a wavelet packet scheme of image compression through embedded zerotree coding,the region of interest coding and adaptive arithmetic coding is constructed.This technology solves the difference between the image quality and the compress rate.The experiment results reveal that the image quality of the regions of interest are better than those by the original embedded zertree algorithm and JPEG.

Improved fast correlation tracking algorithm

ANG Yong-zhi,WEN Yuan-bao

2005, 25(12): 2843-2844.

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A correlation tracking algorithm named Minimum Far Distance(MFD) was proposed to improve the existing Maximum Close Distance(MCD) algorithm.By monotonically decreasing the upper limit of summation,MFD can quickly terminate accumulating on the non-matching points,and finally reduce the total calculation.In order to deal with the template drift problem of MCD,MFD adjusts the pixel close threshold dynamically,and uses another correlation method to filter from multiple matching points that may be exist.As a result,MFD suppresses template drift remarkably,while preserves the virtues of MCD such as standing against noise and partial occlusion.The algorithm also combines correlation matching with the control characteristic of servo system,selects the matching area more reasonably,and thus enables a faster servo control speed.

Robust method for estimating the fundamental matrix

GUO Ji-dong,XIANG Hui

2005, 25(12): 2845-2848.

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After analyzing the characteristics of methods for computing fundamental matrix,a method was presented for robustly estimating fundamental matrix with three improvement.The data set was discriminated into inliers or outliers by minimizing reprojection error.The computation of one order approximation for reprojection error was given.To avoid local minimum,LM algorithm was adopted in last steps of RANSAC(RANdom SAmpling Consensus) algorithm.A very good estimation of fundamental matrix was obtained and the reprojection error was smaller.Experiment results on synthetic and real images demonstrated that the new algorithm is valid and robust.

Fast fractal coding based on detail information classification and structure similarity

MENG Fan,YE Zheng-lin,PAN Lu-lu

2005, 25(12): 2849-2852.

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The conventional fractal coding scheme suffers from long encoding time.A new fractal coding method was proposed based on detail information classification(DIC) and structure similarity(SSIM) index.DIC was implemented based on distribution of detail information which was discrepancy between pixel and its adjacent pixels.SSIM index measured the similarity between range block and domain block from luminance,contrast and structure.The combination of DIC and SSIM index can accelerate the classification and reduce time of matching computation.Experiment results on test images show that the presented method can decrease the coding time whilst maintain decoding quality.

Estimation of fractal dimension for 2-D gray image

ZHANG Zhi,DONG Fu-an,WU You-li

2005, 25(12): 2853-2854.

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The general fractal dimension algorithms of image have the disadvantage of the precision and the speed especially when applied to the high dimension images for the moment.Based on the box counting method,a new bound of box size was put forward.Experiment and theoretical results show that the algorithm is better than Chaudhuri and Sarkar’s classical bound both on the precision and the speed.

Studies on face contour extraction from approximate skin color backgrounds

LIU Rui,WANG Xiao-dong

2005, 25(12): 2855-2857.

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A new face contour extraction method was proposed by useing skin color and multiple information fusion.The method computed skin probability image based on TSL color space,then selected seed point,finally used multiple information to carry out region growing,extracted face contour.The method employed image pyramid process to avoid heavy computing burdens caused by region growth.Experiment results indicated that the proposed algorithm can extract face contour from approximate skin color backgrounds efficiently and accurately,and bears noise endurance and application adaptability.

Research of multi-level association rules mining in distributed database

CAO Hong-qi,JIANG Zhi-feng,SUN Zhi-hui

2005, 25(12): 2858-2861.

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A fast mining algorithm named DMAML_FPT(Distributed Mining Algorithm of Multiple Level based on Frequent Pattern Tree) was presented after researching multi-level association rules mining in distributed database.Comparing with Apriori-like algorithms,DMAML_FPT only need to scan the database for three times,eliminated the need for generating the candidate items,reduced the communication cost,and improved efficiency of data mining.Experiment results show that the algorithm is feasible and efficient.

Chinese text categorization algorithm combined with feedback

CHEN Rui-fen

2005, 25(12): 2862-2864.

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Combining with the traditional training-categorization framework and feedback,a Chinese text categorization algorithm was proposed.This algorithm made the process of text categorization be a "learn-application-learn again" one,added feedback technique to the construction of categorization machine.The efficiency of the algorithm was analyzed.Experiment results show that the algorithm is feasible.

New semantic circle caching model based on pre-define regions in mobile computing

LI Zhi-chao,HE Pi-lian,LEI Ming

2005, 25(12): 2865-2867.

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The concept of pre-define regions and semantic circle was used,then a semantic circle caching model based on pre-define regions was proposed,which can efficiently resolve the problem of semantic relativity.A cost function based on semantic segment distance and valid scope was presented as the basis of caching replacement.The implementation and experiment results of the replacement policy named PDRSCR(Pre-Defined Regions Semantic Circle Replacement) was given in detail.

Missing value estimation for gene expression data based on Mahalanobis distance

YANG Tao,LUO Jia-wei,WANG Yan,WU Jun-hao

2005, 25(12): 2868-2871.

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A imputation method based on Mahalanobis distance was proposed to estimate missing values in the gene expression data.The nearest neighbors were chosen by the Mahalanobis distance between genes,and then the concept of entropy was utilized to obtain estimations of missing values.The imputed values were used for the later imputation.Experiments prove that the method is valid and its performance is higher than the other imputation methods based on k-nearest neighbors for gene expression data.

ESR-Tree: a dynamic index for multi-dimensional objects

XU Huan,LIN Kun-hui

2005, 25(12): 2872-2874.

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With study on the structure and performance of SR-tree(Sphere/Rectangle-tree) and X-tree(eXtended node tree),the split algorithm was improved to make up for the shortage of the SR-tree algorithm.A new multi-dimensional indexing structure ESR-tree(Extended SR-tree) was designed by combining the advantages of the both.With the increase of data amount and dimensions,experiments show that the performance of ESR-tree is much better than that of SR-tree and X-tree.

Second time Web search based on categorized information unit model

WANG Cheng-liang,ZHENG Jiao-ling

2005, 25(12): 2875-2878.

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After investigating two kinds of already existed Information Unit model,a new information unit model named Categorized Information Unit was proposed as searching object on which to conduct the second time Web search.Experimental results show that the model can enlarge and refine the original searching results,promots the original searching pricision.It suggests a new way for Web search.

Prefix encoding scheme for ordered XML trees

ZHANG Jian-mei,TAO Shi-qun

2005, 25(12): 2879-2881.

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On the basis of analyzing order in XML data model and XML query language,a prefix encoding scheme for ordered XML trees was proposed,its efficiency and correctness was demonstrated from uniqueness,determinacy,dynamic,flexibility and conciseness.Meanwhile,the idea of layering encoding was used to solve the problem that the size of labels increased when the size of XML document augments.

Decision tree classification algorithm based on Bayesian method

FAN Jian-cong,ZHANG Wen-yin,LIANG Yong-quan

2005, 25(12): 2882-2884.

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According to the characteristic and essence of data mining and taking advantage of Bayesian method,a new classification method named BD1.0 algorithm was presented.This method combined the prior information and information gain method of decision tree.The design and analysis of the algorithm was introduced too.The experiment results show that the algorithm can deal with dirty data such as incomplete data or inconsistent data,and it is more accurate than only useing Bayesian method or decision tree.It has approximate time complexity with C4.5 algorithm.

Research of content-addressable network

LIU Shu-yu,LI Zhi-tang,LI Yao

2005, 25(12): 2885-2887.

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The new generation of scalable P2P systems adopts routing algorithms which support a distributed hash table(DHT) functionality.CAN(Content-Addressable Network) uses DHT to relocate resources on a virtual d-dimensional cartesian coordinate space.CAN is scalable,fault-tolerant and completely self-organizing.The concept of CAN was introduced,the construction and the routing of CAN was described,several improvements for CAN was also discussed.

Three color marker algorithm based on rate prediction

WANG Wei-dong,GAO Ling,ZHANG Zheng-juan,WANG Jie

2005, 25(12): 2888-2891.

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A new algorithm of data packet marker named three color marker algorithm based on rate prediction(Rate Prediction Marker,RPM) which fit for differentiated service was proposed.RPM algorithm is based on online traffic predictors algorithm.Network flows in DiffServ network were either divided by classifier or entering into marker makes flow prediction ahead of one period by RPM algorithm based on online traffic predictors algorithm.The packets were marked according to the results of prediction and the average weighed value of history flows data.When the sources may enter the recovery period of TCP congestion,the network available bandwidth was proportionally designated to serve congregation flows,and this raised the network bandwidth utilization rate.Simulation and experiment’s results show that RPM algorithm has much higher performance when influencing aim rate and bandwidth’s throughout compared with the existing algorithms,and get fairly fairness and bandwidth utilization rate.

Research on topology control for energy efficiency in wireless Ad Hoc networks

HOU Hui-feng,LIU Xiang-wen,HU Han-ying

2005, 25(12): 2892-2895.

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High energy efficiency is one of the most important targets for Ad hoc network design,and topology control is an effective measure at network level to achieve this goal.Two basic topology control mechanisms for energy efficiency were introduced firstly.And then,more attention is paid on the analyzing and summarizing of present research on energy efficient topology control that are based on transmission power adjustment.At last,some promising directions are suggested.Then present research on energy efficient topology control based on transmission power adjustment was analyzed,and some promising were suggested.

A novel optimization scheme for EDCA

SUN Qiang,LIU Tong-pei

2005, 25(12): 2896-2898.

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To guarantee the QoS of WLAN(Wireless Local Area Network) after the network load increased,the technology of reserved contention window maintenance was applied to EDCA mechanism.When network was in low load,the performance was the same as the original access mechanism.As the load increased,it could greatly reduce the collision probability under stable condition.Therefore it can not only support QoS of the high priority traffic,but also improve the throughput of the whole network.

A multimedia distributed service based on P2P

WU Zhao-fu,XU Xian-bin

2005, 25(12): 2899-2900.

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In P2P network with two layers,intergroup replication scatters media contents into groups so as to improve the efficiency of media content delivery between the group where a request is issued and the group where the content is stored,and intragroup replication copies media contents into peers for improving the availability of the content.Simulation result show that the latency in P2P based on the architecture is 20% less than that of the FreeNet and 50% less than that of the randomly replication system.Simulation results also show that the video quality in the system is much better than that in the other two systems.The P2P-based approach is distributed,scalable,cost effective.

Research of Web service based metasearch engine

LI Ai-min,ZHANG Jing,LU Xiao-feng,LIANG Rong

2005, 25(12): 2901-2903.

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The Web service and metasearch engine technology were introduced,then a Web service based metasearch engine architecture was presented.This system could fit for the demand of data traffic on multi-network or multi-system and flexible integration in various systems.Architecture,idea of design,work principle and functional modules of the system were described in detail.

Analysis and simulation of ESSDRR

WANG Ya-ping,ZHOU Xing-she,YAN Shou-meng,ZHANG Fan

2005, 25(12): 2904-2907.

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The existing algorithms usually fail to satisfy the QoS guarantee features and the low complexity.An algorithm called Even Service Sequence-based Deficit Round-Robin(ESSDRR) was proposed,which inherits merits from both WF2Q and DRR.To estimate performance of ESSDRR in end-to-end delay and short-term throughput property,extensive simulation experiments have been done using NS2 in the same condition.And comparison has been made among ESSDRR and other three well-known scheduling schemes.Results show that ESSDRR has good QoS guarantee property and low time complexity.

An ant colony system algorithm rooted in Dijkstra strategy

WEI Sui-xian,HUANG Sheng-hua

2005, 25(12): 2908-2910.

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To find out QoS routing quickly and reliably,an new ant colony system algorithm rooted in Dijkstra strategy was suggested out.The source code flooded searching ants to all its adjoining and QoS-satisfied nodes.Every adjoining node selected out the best-performance one due to an early-setted judgmental function from all the arrived ants,then copied and flooded it again.The ants went on flooding until it got to the aim node at last.After searching all the possible routs between the source node and the aim node,this algorithm must be able to find out the QoS routing fitted for request.As proved in example followed,this algorithm has virtue of briefness,efficiency and strong convergence.

Research on the security of mobile IPv6 dynamic home address discovery

LI Gang

2005, 25(12): 2911-2913.

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The security feature of DHAAD(Dynamic Home Agent Address Discovery) procedure was analyzed,and a solution was proposed to protect it.The solution authenticated the bi-directional DHAAD messages between mobile node and home Agent,and encrypted the home Agent address list in the message from home Agent to mobile node.The solution can protect the DHAAD procedure against Denial-of-Service attack and the theft of information on home link.Then the evaluation of the solution was given,and it was realized in the Mobile IPv6 demonstration network.

Study on device grid technology

YUAN Li-xiang,WANG Wen-yong,LUO Guang-chun

2005, 25(12): 2914-2915.

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The background,traits,current research situation and development orientation of device grid were discussed.An architecture of device grid system was brought forward and the process of resource scheduling of device grid system was analyzed.In terms of the particularity of the device grid environment,a security mechanism of Device Grid system was put forward and analyzed.Finally,the experiment result was described.

Inter-AS load balancing mechanism and performance analysis

GE Jing-guo,MA Hong-wei,QIAN Hua-lin

2005, 25(12): 2916-2918.

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A distributed and dynamic load balancing mechanism was proposed.To preserve per-flow packet ordering and support unequal weighted distribution,hashing-based algorithm with dynamic adapting according to history records on traffic was used.Simulation experiments evaluate the effects of hash-tuning with varied time window and threshold.

Research on economy-based optimisation of admission policy on a grid cache

SONG Feng-long,LIU Fang-ai

2005, 25(12): 2919-2920.

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To relax the latency and maximise the income of local storage broker,the economic model was used to optimizing the admission policy on grid cache,and an effective admission policy through computing the value difference when caching an object was proposed,which can solve the income conflict.Test results proved the effectivity of the policy.

Practical parallel algorithm for all-pairs shortest-path problem

ZHOU Yi-ming,SUN Shi-xin,TIAN Ling

2005, 25(12): 2921-2922.

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Aiming at the all-pairs shortest-path problem in the directed graph,a practical parallel algorithm,which based on the Floyd algorithm with an extended path array,was brought forward on 2-D mesh network.The planar evenly partition method was chosen for task division in this parallel algorithm.The parallel algorithm was implemented on MPI on NOW.The theoretical analysis and the experimental results prove that the parallel algorithm is an efficient and scalable algorithm.

New self-routing and non-blocking MINS based on binary splitting concept and omega network

ZHANG Lian,GU Nai-jie,LIU Gang

2005, 25(12): 2923-2924.

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A design for a new self-routing multicast network which can realize arbitrary multicast assignments between its inputs and outputs without any blocking was proposed.The network design used a recursive decomposition approach and was based on the binary splitting concept.It was recursively constructed by cascading a binary splitting network and two half-size multicast networks.The multicast assignments were copyed and binary splitted by the first Omega network and then routing through the N×N Omega×Omega-1 networks and the N/2×N/2 Omega×Omega-1 networks and so on.All kinds of Omega×Omega-1 networks have different size,but they can be connected and routing parallel.This new multicast network uses O（Nlog2N） logic gates,and has O（log2N） depth and O（log2N） routing time.It is compared favorably with the previously proposed multicast networks.

Off-line handwritten amount in words recognition using classifiers combination method based on HMM

WANG Xian-mei,YANG Yang,WANG Hong

2005, 25(12): 2925-2927.

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A new combination scheme was proposed.First,three individual classifiers were constructed with normalized wavelet,stroke density and the percentage of the number of black pixels.Then the combination based on different methods was studied.The experiment results show that the proposed approach can achieve high performance.

Research of speech assessment based on reature comparison

LIU Zhen-an,LUO Yong-zhao

2005, 25(12): 2928-2930.

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In order to impersonally assess the quality of the following speech in the language speaking training,and carry out it in embedded system,a method of speech assessment based on feature comparison was proposed.The input speech was analysed,and the feature was extracted to match with the reference speech.The result was given by the mechanism based on the similarity of the speech.Experiment shows that the algorithm complexity is low,and the result of the assessment is approximately consistent with the subjective feeling.

Lane and road detection based on colorful image

GUAN Yan-ping,HE Yue,LIU Pei-zhi,Lü Lin

2005, 25(12): 2931-2934.

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A new method of structureless road detection based on colorful image was presented.The image was first divided into several small foursquare areas.And then,the characteristic information of road was gotten from the area which is assumed to be the road area.According to these information,the small foursquare areas could be classified.Using the method of self-motion threshold segmentation,each of the foursquare areas which include the shoulder of a road,were segmented into the road area and the other area.Lastly,the spots inside the road and the disconnected areas outside the road were eliminated.This method avoids analyzing each pixel of image.It performs with less calculation and higher speed,and satisfies robust real-time basically.It also resists the effect of shadows and water marks.

Project of an E-Bank system based on the technology of the iris recognition

CHEN Si-jie,ZHENG Jian-sheng,DAI Yong-hong

2005, 25(12): 2935-2937.

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A method to locate iris was introduced,in which Integro-Differential Operators were combined with Gradient-Decomposed Hough Transform.In the Daugman algorithms,a non-scattered man-made light could arouse the bright point effect,which could be effectively reduced by the method.A new E-Bank solution was designed useing it.And the solutin can enhance the lever of security,and satisfy the customer,bank and CA.

Research and design of software GPS positioning component

ONG Guo-hui,LI Si-kun

2005, 25(12): 2938-2939.

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A software GPS positioning receiver which can be easily integrated into embedded system was designed.The receiver has three work modes: autonomous,snapshot and assisted.According to the availability of GPS signals,the receiver changes work mode neatly,so as to offer steady position information with low power consumption and low CPU burden.Field tests were done,and the results indicated the good performance of the positioning receiver.

Analysis of the customer’s behavior based on clickstream of product’s 3D model

XIE Ling,CHEN Xin-du,CHEN Xin

2005, 25(12): 2940-2942.

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The Web Server log files were extended and an operation model based on user’s operation log files and customer’s information was established,the interestingness of customer in product and product series was mined using the FP-growth method.The results shows that the models and methods are useful for dicision-making of product development and marketing strategies in enterprises.

estament signing protocol on Web based on elliptic curve

WANG Xiao-ming

2005, 25(12): 2943-2944.

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Testament signing protocol was designed based on elliptic curve,according to the designated confirmer signature idea.This protocol can protect testator’s testament from being copied,spreaded and changed.The testament can be authenticated and protected when testator died.Moreover,this protocol can defend any cheats and attacks,and it is secure,efficient,simple and practical.

Study on the model of information transmission and controlling of the large-scale irrigated area based on information flow

WANG Cheng-jun

2005, 25(12): 2945-2947.

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For further investigate the essential element of information expressed of large-scale irrigation area and constructs the overall model of irrigation area system,the system engineering method was used to analyses the information source and information flow of irrigated area.By this method,the connection and state between each element transmit the relation in the system was described systematically and a model of Information transmission and controlling of the large-scale irrigated area was constructed.The application of this model to the irrigation are informationization shows that this model has offered the feasible quantization model for realization and accurate control of the information system of irrigated area.

Design of multiple features and multilayer classifiers for handwritten character recognition

WU Li-yun,WANG Wen-wei,ZHANG Ping,CHENG Jun

2005, 25(12): 2948-2950.

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A novel method for the recognition of commonly used handwritten Chinese characters in bank and digits was presented.Considering diverse classification requirements,different features were selected,an integration of clustering and Multilayer Perceptron neural networks was utilized.The experiment demonstrates that the proposed approach is promising.

Computer simulation research based on Chinese characters and their components clustering

FANG Xin,MU Zhi-chun,CHEN Jing,DU Da-peng

2005, 25(12): 2951-2953.

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In this paper,a new algorithm named SOMNET was presented based on the theoretical foundation of Self-organizing Feature Map algorithm.Using Artificial Neural Network,SOMNET algorithm realizes similar-featured Chinese characters clustering and Chinese character components clustering.The display effect of Chinese characters and their components was analyzed,and the application of SOM model was described from multiple points of view.The research outcome is expected to be helpful to Chinese character cognition and teaching of foreign students’ second language acquisition.

Adopting UML method in firmware development

DONG Lei-jun,HOU Zong-hao,ZHANG Hui-juan

2005, 25(12): 2954-2956.

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Expatiates explains how to adopt RTUML methods in firmware analysis,development,implementation and testing under Rhapsody platform through the example of SESI-II neon light controller.A new method is discovered in developing firmware system,which is called Real Time UML,different from the traditional flow-based C language method.

Network operation monitoring system based on Visio

MENG Xin,XIAO Zong-shui

2005, 25(12): 2961-2963.

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The common requirements of network monitoring system was analyzed and a schema to design the network monitoring system based on Microsoft Visio 2003 was put forward.Several main problemes of this schema were discussed with some resolvents of the difficulties provided.The practice showes that the schema is feasible,and it is advantaged than traditional developing method.

Implementation of the office log system of MVC design pattern based on J2EE platform

FENG Xiang-zhong,WANG Ping

2005, 25(12): 2964-2966.

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The J2EE technologies and MVC design pattern was analyzed.Using MVC design pattern in the development of software,the process of developing software can be simplified,and the quality and the maintainability of software can be improved.Those techniques were used to implement a system of the Office Log.

Web QoS based on content switching

ZHU Li-cai,HUANG Jin-jin

2005, 25(12): 2966-2967.

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The principle of content switching was introduced,and the way to guarantee the Web QoS of the end to end through content switching was analyzed.An instance was given out to show how to realize Web QoS in host.

P-TOSSIM: a task scheduling simulator for TinyOS sensor networks

XIA Jing-qing,ZHANG Rong

2005, 25(12): 2968-2970.

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TOSSIM can not support simulating two applications simultaneously.Firstly,we modified the open source code of TOSSIM to make it able to simulate multiple applications simultaneously.Then we implement P-TOSSIM based on the revised TOSSIM which is a task scheduling simulator for TinyOS sensor networks.P-TOSSIM is able to simulate all applications in the sensor networks.

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