Table of Content

30 June 2004, Volume 22 Issue 2

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Articles

The Applications of Differential Cryptanalysis in Sequence Cipher Attack

LI Chao, HUANG Jian-zhong, XIANG Pan-pan

2004, 22(2):  127-131. 

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In this paper,we point out some properties of the differential sequence, discuss the applications of differential cryptanalysis in sequence cipher attack and provide an attack sample.

On the Construction of Orthomorphic Permutations in Cryptosystems

ZHU Hua-an, XIE Duan-qiang

2004, 22(2):  132-135. 

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Orthomorphic permutations have good characteristic in cryptosystems.In this paper,the properties of orthomorphic permutations are discussed and some results are obtained. These results are useful in constructing orthomorphic permutations.

A Scheme of Direction-Finding and Ranging in the Presence of Multipath Interference for a New Integrated System of Communication and Radiolocation with Space-Time Modulation

SHI Ting-xiang, SONG Mao-zhong

2004, 22(2):  136-139. 

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We carry out research on how to promote the accuracy of direction-finding and ranging in the presence of multipath interference in a new integrated system of communication and radiolocation with space-time modulation. First, we analyze how this space-time signal is received and demodulated in a multipath environment. Second, multipath channel pulse response is estimated without taking channel noise into account, a kind of joint-estimation, which is combined with a simple new algorithm for extracting multipath components is realized. Finally, simulation results are given. The results of the simulation demonstrate that the accuracy of the location is improved after adopting the method.

A Traffic-Balanced AODV

YU Xü-tao, ZHANG Zai-chen, BI Guang-guo

2004, 22(2):  140-143. 

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Compared with the traditional table-driven routing protocols, the AODV routing protocol reduces routing overhead in dynamic maintenance of routes. However, with AODV, network performance degrades rapidly with the increase of offered load. In this paper, we propose a simple and effective modified version of AODV, named Traffic-Balanced AODV (TB-AODV). In this protocol, each node, basing on its local MAC load status decides whether it can accept routing requests from other nodes or not. Simulation results show that TB-AODV achieves better overall performance than AODV.

The Performance of MC-DS-CDMA Based on the Multi-band Complex Wavelet

YU Xiang-bin, BI Guang-guo

2004, 22(2):  144-148. 

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In this paper, through analyzing the principle of MC-DS-CDMA, we propose a novel multi-band complex wavelet based on the MC-DS-CDMA system by adopting the optimized multi-band complex wavelet. We also investigate the system bit error rate (BER) performance in the multi-path Rayleigh fading channel. Meantime, the space diversity combining (SDC) technique is exploited to further perfect the system's performance. Simulation results show that the proposed system outperforms the conventional MC-DS-CDMA and the real wavelet packet based MC-DS-CDMA, it has superior capability against fading. The proposed SDC-based system with lower BER can significantly strengthen the capability to combat multi-path interference and multi-access interference (MAI).

Element-Wise Division Algorithm for DOA Estimation in DS-CDMA Systems

WANG Wei-xin, WU Zhen-yang, PENG Yue-xing, LIU Chen

2004, 22(2):  149-152. 

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In this paper, an effective DOA estimation algorithm is presented for DS-CDMA systems under multi-user environment. First, the information associated with each path is extracted. Then, DOA's are efficiently resolved using the proposed element-wise division operations. The algorithm requires neither complex eigenvalue decomposition operations nor source number estimation. In addition, paths pairing are matched automatically. Generally speaking, the proposed algorithm is high in resolution and easy to implement in practice. Simulations confirm the effectiveness of the algorithm.

A Study on the Adaptive Filter for Channel Estimation in the Wideband CDMA System

SHENG Bin, YOU Xiao-hu

2004, 22(2):  153-156. 

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Basing on the study of the mean square error (MSE) of channel estimation in the wideband CDMA system, we proposed a novel adaptive channel estimator by using the cross-correlation of channel estimate as its coefficients. The theoretical MSE performance of the proposed filter, Wiener filter and lowpass filter are also compared in this paper. Computer simulation results show that through adaptive algorithm, the proposed channel estimator can provides good performance over a wide Doppler frequency range supported by 3G, using only noise variance know-(ledge.) Back

A Study on the Decoding Algorithm of the V.90 Digital Modem

LI Qiang, BI Guang-guo

2004, 22(2):  157-161. 

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The purpose of coding in the V.90 digital modem is to shape the transmitted signal spectrum and constellation instead of error correction. The computational load of spectrum shaping is much heavier than that of constellation shaping. The sign bits selection is a problem of searching the optimum path in the trellis, thus Viterbi algorithm can be used. This is equivalent to placing a conventional decoder in the (V.90) digital modem encoder. Logically speaking, the (V.90) digital modem decoder is like a traditional encoder. From the above basic idea, we have represented the modification rules constrained by 2-state trellis as a convolutional code, derived all the formula needed for decoding, and finally proposed a decoding algorithm for the V.90 digital modem.

A Novel 200V P-Channel Power MOSFET and the Process for the PDP Scan Driver IC

YI Yang-bo, SUN Wei-feng, SUN Zhi-lin, CHEN Chang, LU Sheng-li

2004, 22(2):  162-166. 

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In this paper, a novel P-channel high voltage extended drain lateral double-diffused MOSFET(ED-LDMOS) is proposed for the PDP scan driver IC. The breakdown voltage between source and drain is above 220V and the gate also has a breakdown voltage of 220V. The extended drain structure can reduce the peak electric field by 60% and the current crowding effect around P~+ drain, so it can suppress the turn-on of the parasitic bipolar transistor. Also an isolated N-well near P~+ source and N~+ buried layer at the bottom of the device are added to further reduce the leak current and improve the breakdown voltage by 40V. The process is compatible with the 0.6μm standard LV-CMOS process. A margin etch method for the thick gate oxide film is specially proposed. It can prevent a short circuit between the gate and source caused by photolithography offsets.

Low Peak Power Scan Testing Based on Partitioning Test Operation

LI Rui, YANG Jun, WU Guang-lin, LING Ming, SHI Long-xing

2004, 22(2):  167-172. 

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In this paper, we propose a new method to solve the peak power problem by partitioning the operation of flip-flops in the same clock domain during the scan test. This method need not regenerate test patterns so that the test patterns generated before partition can be reused. The experiments show that the proposed method can reduce the consumption of peak power, ave-rage power and energy simultaneously with a slight increase of test time.

The Signal Flow Graph Solutions of Nonlinear Algebraic Equations and Their Applications

SHANG Hui-liang, LI Feng, LI Lin-lin

2004, 22(2):  173-177. 

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Signal flow graph solutions of nonlinear algebraic equations are presented in this paper.The use of Mason Formula for linear algebraic equations is extended to nonlinear algebraic (equations).The method can obtain "general solutions",and "special solutions" of nonlinear algebraic equations and can be used in the analysis of all nonlinear circuits and systems.

A Random Sampling Algorithm for Fundamental Matrix Robust Estimation

YANG Min, SHEN Chun-lin

2004, 22(2):  178-182. 

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Epipolar geometry is the intrinsic projective geometry between two views of a static scene. It is independent of scene structure, and only depends on the camera's internal parameters and relative pose. The fundamental matrix encapsulates the whole epipolar geometry and accurate and robust estimation of the fundamental matrix is very important for many computer vision applications. In this paper, a robust algorithm is used to estimate the fundamental matrix——the random sample algorithm. Given that a large proportion of the data (the set of corner point pairs) may be useless, a small subset of the data (seven correspondences for a fundamental matrix) is feasible to estimate the parameters, and this process is repeated enough times on different subsets to ensure that there is a 95% chance that one of the subsets will contain only good data points. The best solution is that which maximizes the number of points whose residual is below a threshold. Once the outliers are removed, the set of points identified as non-outliers may be combined to give a final solution. Experiment with real images verifies that the random sample algorithm is both accurate and robust.

A New Plane-Corresponding Method for Based Camera Calibration in Vision Measurement

WANG Xun-si, DENG Shan-xi, YANG Yong-yue

2004, 22(2):  183-186. 

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Camera calibration is the most important part in vision measurement. This paper reviews some of the founder techniques recently reported in literature. The paper is organized as follows:There are some math models calibration, such as the matter-image corresponding model, CCD figuring model, etc. The new plane-corresponding method for calibration is described. Application of the calibration method in the non-touch measurement is shown. The theoretical precision of the model is analyzed. Some important experiment data are shown. Finally the concluding remarks are given.

A Research on a Non-scanning 3-D Profile Optical Focus Detecting System

WANG Yong-hong, YU Xiao-fen, YU Jian-wei, HUANG Qi-sheng, XU Ke-jun

2004, 22(2):  187-190. 

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A non-scanning 3-D profile detecting system based on astigmatic method is developed. In this detecting system, a 2-D light source array produced by a micro-optic component is used to form a parallel micro-astigmatism system. The whole-field detection of measuring plane is realized simultaneously. As the differential arithmetic of facula intensity is used, the noise and the shift of light source can be restrained effectively and the high axial resolution is achieved at a larger sampling interval. The measuring efficiency and accuracy are increased simultaneously. The construction and working principle of the no-scanning 3-D detecting system is studied, the method of 3-D profile reconstruction is recommended, and the experiment result is obtained as well.

Sub-Pixel Edge Detection Based on Spatial Moment and Zernike Moment

DING Xing-hao, DENG Shan-xi, YANG Yong-yue, ZHAO Qian-cheng

2004, 22(2):  191-194. 

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The theories of spatial moment and Zernike moment are presented. An edge model with four parameters has been built and the relations between edge parameters and the two moments are analyzed respectively. The values of edge parameters are calculated to get the edge image. The method can locate edges to sub-pixel.

Research on the Cooperation Strategy for the Multiple Microrobots Inspection System Between Pipes

LI Zhen-bo, CHEN Jia-pin, ZHANG Ya-nan, SU Jian-bo, SUN Lin-zhi, GONG Zhen-bang

2004, 22(2):  195-199. 

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In this paper, a cooperation strategy was designed for a multiple microrobots system, in order to realize the system task through the cooperation among the robots, according to the specially equirement of the microrobots inspection system. The results were demonstrated through experiments.

The One-Time Scanning Incremental Mining Algorithm of Association Rules Based on a Transaction Thread Tree

YE Ning, DONG Yisheng, WANG Houli

2004, 22(2):  200-204. 

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A novel incremental mining algorithm of association rules is presented in this paper. First, transaction database is compressed and stored in a transaction thread tree (TT-tree). Then the index table of the nodes is established. Finally, all paths from leaf node to root node are obtained with the reverse search method. The frequent sets are included in these paths. The algorithm is very efficient since it scans transaction database only one time. In addition to efficiency, our algorithm is both scalable and incremental. The experimental results show that our algorithm is 10 times faster than that of the Apriori method.

An Approach for Computing Dynamic Slicing Based on Coverage-Testing

YI Tong, WU Fang-jun

2004, 22(2):  205-210. 

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Dynamic slicing is an important approach to analyze, understand and maintain programs, which has been widely used in activities of software engineering and reengineering. In this paper, the existing methods based on graph reachability are firstly analyzed, and a coverage-testing-based method for computing dynamic programs slicing is then presented. The key of this method is to construct a coverage-testing-based dynamic dependence graph (CTDDG), which makes use of both dynamic information and static information to get execution dependencies. Besides efficiency, our approach overcomes the limitations of previous dynamic slicing methods, which have to redo if slicing criterion changes.

A Development Study of Software Based on Virtual Components

LIU Hui, MIAO Huai-kou, LIU Jing

2004, 22(2):  211-216. 

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Industrialized development of software is one of the most interesting but difficult research fields in software engineering. This article discusses the most important problems:component models and component composition. Investigating representative component models, this paper proposes a new component model. Based on this model, it brings forward a new concept:the virtual component. A development model with virtual components is explained in the end.

A Qualitative Research of Lung Tumor Based on Quantitative Three-Dimensional Shape Analysis

JIANG Xiao-tong, LUO Li-min, WANG Jia-wang, PAN Xiao-min, LUO Yong-gang

2004, 22(2):  217-222. 

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The computer-aided diagnosis system of lung tumor has great clinical significance for alleviating doctor's pressure and reducing misdiagnosis rate. In this paper, a new method of lung tumor identification based on quantitative three-dimensional shape analysis is proposed. According to the character of CT data and doctor's clinical experience, we defined three two-dimensional shape descriptors correlating with tumor type from different points of view; on this basis, four three-dimensional shape descriptors were defined as input value of radial basis function neural net to realize the automatic classification of lung tumor. The experiment result demonstrates that these shape descriptors can well represent the tumor character:The identification rate is to benign tumor 87.5% and that to malignant tumor is 69.44%.

The Numerical Simulation of Friction Status on the Rake Face and Flank Face of Cutting Tools

XIE Feng, LIU Zheng-shi, YANG Hai-dong

2004, 22(2):  223-227. 

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Based on the analysis of friction between the rake face of metal-cutting tool and the chip as well as between the flank face of metal-cutting tool and the machined surface, the friction process and the chip forming in the two-dimensional metal cutting process are both numerically simulated by means of FEM software. The equivalent stress between the contacting nodes on the friction face of the chip-cutting tool is calculated. The modeling by FEM method and the calculating process are also described. Through the comparison between the calculating results of the simulation of the shearing angle and the experiment data obtained by the rapid tool-dropped method, the feasibility of this method is confirmed. This method is new and unique. Its application will be helpful to the theoretical study of metal cutting and the design of the cutting tools.

Forecasting Characters of L⁹(3⁴) Orthogonal Test Based on the Artificial Neural Network

CAI An-hui, PAN Ye, LIU Yong-gang, SUN Guo-xiong

2004, 22(2):  228-232. 

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Five sets of results for different L⁹(3⁴) orthogonal tests were used as the training-study samples, the forecasting characters of L⁹(3⁴) orthogonal test were researched on the basis of the artificial neural network. The results showed that the self-contained orthogonal sample collection was the basic training-studying cell and was indivisible. Their forecasting results were tallied with the test results. When others samples were added into the self-contained orthogonal samples or the self-contained orthogonal samples were reduced, the forecasting results would be completely irresponsible. Under the same test conditions and with the same orthogonal test type, the self-contained orthogonal sample containing large information could forecast other self-contained orthogonal samples with small information. It provides a significant novel test-design approach for the orthogonal test.

A Orthogonal Experiment Study of Enhancing the Wear-Resistance of Polyoxymethylene Composite

LONG Chun-guang, WANG Xia-yu

2004, 22(2):  233-237. 

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The Ekonol/G/POM composite was prepared by means of the orthogonal experiment design and the torque rheometer blending-compressing model method. A study has carried out on the wear resistance of the material through the analyses of variance and range. The results show that preparing Ekonol/G/POM composite by the orthogonal design can greatly reduce the number of experiments, and enhance the work efficiency. Both the analyses of the variance and range have come to the same conclusion that the Ekonol content is the most important factors to affect the wear resistance of the composite, while the cooling method comes next.

A Study on Transmission Characteristic of the Modulation Infrared Pulse Wave Used in Detecting Flaw Within an Insulation

ZHAO Long-zhang

2004, 22(2):  238-241. 

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The differential equation of heat energy wave transmission expresses the unbalanced state of heat in the heat energy wave transmission formed by the modulation infrared pulse wave injected into an insulation as well as expresses the relationship between the thermal diffusion coefficient, medium consistency and mechanical performance. It furnishes the medium information heat transmission theory within the insulation and its calculation method. Dynamic response can determine the temperature distribution of the insulation and the flaw. Measuring the swings and phases of radiation signals under different modulation frequencies and increasing the peak value of heat energy waves can find corresponding parameter values and determine the place, thickness, heat conductance and thermal diffusion coefficient of a flaw. The technique is especially applicable to complex material, surface coating or plating to detect the inanition or cracks of different insulations.

The Performance Analysis of a Brayton Cycle of an Ideal Bose Gas

LIU Jing-yi, LIN Bi-hong

2004, 22(2):  242-246. 

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The equation of state for an ideal Bose gas is derived by using the expressions of the pressure and particle number of an ideal Bose gas. Basing on the equation of state and the thermodynamic properties of an ideal Bose gas, one can obtain the general expressions of the efficiency and work output of a Brayton power cycle using an ideal Bose gas as the working substance. The effect of quantum degeneracy on the performance of the cycle under quantum degeneracy conditions is analyzed. It is shown that the work output of a Brayton heat engine working with ideal Bose gases is greater that of a classical Brayton cycle and the quantum degeneracy of the gas does not affect the efficiency of the cycle. The results obtained here may provide theoretical basis for the design of a Brayton cycle working under quantum degeneracy conditions.

Minimizing the Maximum Lateness on a Two Machine Flowshop with Batch Processors

CHEN Yue, SUN Shi-jie, SONG Zheng-fang, HE Long-min

2004, 22(2):  247-251. 

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This paper considers the following problem:n jobs need to be processed on two machines (M₁,M₂) successively. The deadline for job j is d_j, and the processing times of job j on M₁, M₂ are a_j, b_j, respectively. Both machines are batch processors. This means n jobs are grouped into several batches on M_i, i=1,2, respectively, and the machines process the jobs in same batch simultaneously. The processing time of a batch is equal to the longest processing time of all the jobs in this batch. Thus all the jobs in same batch are processed in the same length of time on the given machine, and the jobs will be also shifted in batches. We take the maximum lateness as our objec function for minimization. After pointing out that this scheduling problem is NP-hard, we give some special cases that can be solved in polynomial time and construct the corresponding dynamic programming.

The Asymptotic Stability and Geometry-Velocity Stability of the Time-Varying Discrete Dynamic System

ZHU Wei

2004, 22(2):  252-254. 

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This paper presents a sufficient condition for the asymptotic stability and geometry-velocity stability of the time-varying discrete dynamic system.

The Application of Fuzzy Analysis Method in the Risk Sequences of Financial Organizations

WANG Zhong-chen, YU Kui, ZENG Ming

2004, 22(2):  255-257. 

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Through the synthesization of the fuzzy sequence models of the branch systems, the fuzzy sequence model in the risk sequences of the whole financial organizational system is established by means of combining the system with fuzzy analysis.

A Convergent Analysis of the Fast Decomposition Projective Method for Solving the Electromagnetic Problems on Multi-branch Domains and Its Application

SUN Lian-you, TANG Jin-long, HONGWei

2004, 22(2):  258-260. 

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This paper analyzes the convergence of decomposition projective method(DPM) and fast decomposition projective method(FDPM), both of which aim at solving the electromagnetic problems on multi-branch domains. This paper also proves that the convergence rate of FDPM is fast than that of DPM. FDPM's application shows that its convergence rate is very quick. The iterative number of FPDM equals to about one third of the former method.

A Robust Speech Transfer Path Modeling Technique and Its Applications

HU Xiao, HU Ai-qun

2004, 22(2):  261-264. 

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According to the features of speech signals, the paper proposes a robust speech transfer path modeling system. After adding a low-level broadband random training signal to eliminate the modeling mismatch, it removes the speech signals in the system output by using an adaptive prediction filter, and it also modifies the distortion of the training signals due to the APF by using a compensation filter. The computer simulations confirm that the novel modeling system can be widely applied to echo cancellation systems and speech enhancement systems.

Research on Bluetooth Security at Link Level

MA Yue, CAO Xiu-ying

2004, 22(2):  265-268. 

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The paper discusses the security mode in the Bluetooth information baseband transmission——link level enforced security. It analyses and implements the key management,key generation and initialization, and the algorithm of encryption and authentication. In conclusion the author put forward his view on Bluetooth security.