Table of Content

28 September 2010, Volume 44 Issue 09 Previous Issue    Next Issue

Automation Technique, Computer Technology

Select

Improved Guided Local Searchbased Algorithm for Period Vehicle Routing Problem JIANG Guishana,JIANG Zhibinb,LIU Shujunb 2010, 44 (09):  1171-1175.  Abstract ( 3527 )   Save Based on the traditional static penalty strategy of the Guided Local Search algorithm (GLS), a dynamic penalty strategy was proposed. Then an improved GLS algorithm was developed to solve the period vehicle routing problem (PVRP). Standard instances of the PVRP were applied for computational tests. Comparison of static penalty and dynamic penalty strategies show that the improved GLS algorithm is efficient and effective for the PVRP. Related Articles | Metrics

Select

An Intrusion Detection Method Based on Graph Theory BAO Zhen,HE Di 2010, 44 (09):  1176-1180.  Abstract ( 3882 )   Save An intrusion detection method based on graph theory was proposed. The method introduced the idea of graph theory into intrusion detection system. By transferring the similarity relationship between data objects into the adjacency matrix in the graph, and transferring the adjacency matrix into an association matrix, it could reflect the relationships between data objects clearly. The steepest descent method was used to calculate the optimal transition matrix, and obtain the result of data clustering by transferring the association matrix into a block diagonal matrix, which could identify clusters of normal data and intrusion data. Meanwhile, KDD CUP 1999 dataset was used to simulate. The result shows that the proposed method has a higher detection probability under the condition of low constant false alarm rate compared with fuzzy Cmeans clustering algorithm. Related Articles | Metrics

Select

A Robust Landmark Localization System for Outdoor Mobile Robot WANG Jingchuan1,2,CHEN Weidong1,2,ZHANG Xu1 2010, 44 (09):  1181-1186.  Abstract ( 3893 )   Save A landmark recognition and localization system with an enhanced robustness against large changes of lighting conditions eas presented for outdoor mobile robot. A near infrared illuminator was used for reducing the interference of natural light and shadow. The omnidirectional camera could capture images with more landmarks in a wide range of environment. For improving the landmark's recognition rate, a dynamic OTSU binarization method was adopted for enhancing the feature of landmarks in uneven lighting image. The outdoor realrobot localization experiments demonstrate the system’s robustness. Related Articles | Metrics

Select

RRASAP Security Verification Based on Model Checking for RBAC Access Control Systems ZOU Lin1,2,PAN Li1,2 2010, 44 (09):  1192-1196.  Abstract ( 3618 )   Save A new security analysis problem named rolerole assignmentsecurity analysis problem(RRASAP) was proposed. The impact of role hierarchy changes on security was analyzed, and the computational complexity of this problem proved. An algorithm of translating RRASAP into a Model checking formalism was also proposed to do automatic verification, and to prove the feasibility of this method. The experiment shows that this algorithm can automaticly solve RRASAP in expected time. Related Articles | Metrics

Select

A Network Risk Assessment Model Based on Network Global Privilege Graph ZHANG Baowen1,LUO Zheng2,XUE Zhi1,YIN Ying1 2010, 44 (09):  1197-1200.  Abstract ( 3680 )   Save A concept of global network privilege graph and its generation method were proposed. Then a novel network risk assessment model based on privilege graph was proposed. The algorithm and model were verified using a demonstrative network. The results show that the assessment achieved by the model is more exact than common methods because the model considers the quantitative data of vulnerabilities and other security configuration information. Related Articles | Metrics

Select

Optimum Design of Complex Flanging Trimming Line Based on Error Correction Method BAI Yanchao,CHEN Jieshi,CHEN Jun 2010, 44 (09):  1201-1205.  Abstract ( 3484 )   Save Optimum design of complex flanging trimming line was studied. An iterative method based on errorcorrection was proposed. Based on finite element method (FEM) simulation of LSDYNA, the blank was corrected according to the error values of simulation results and the target curve. After one or two iterations, an exact trimming line was obtained. The program could automatically call LSDYNA solver, which greatly increased the efficiency of the trimming line optimization. A flanging simulation study proved that the method was effective. Related Articles | Metrics

Select

Research on Accelerating Controlling Method of Waterjetdrived Ship by Integration of Simulink with MFC HUANG Bin,WANG Yongsheng 2010, 44 (09):  1206-1210.  Abstract ( 3856 )   Save A waterjet propulsion system simulation program was established by integrating Simulink with Microsoft Fundation Class (MFC). Two methods, the synchronization accelerating method and asynchronism accelerating method, were proposed and simulated by using the program. The results show that the former demands shorter time with better maneuverability, while the latter has better practicability. Finally, a more practical accelerating method was proposed. Related Articles | Metrics

Select

An InterVehicle Communication Protocol for MultiVehicle Cooperation Based on RRALOHA PENG Xinronga,YANG Minga,XIE Qiangdea,WANG Binga,WANG Chunxiangb 2010, 44 (09):  1211-1216.  Abstract ( 4017 )   Save A medium access control （MAC） protocol was proposed based on Reliable Reservation ALOHA (RRALOHA) in order to meet requirements of the multivehicle cooperative system for realtime, reliability and distributed property. The realtime capability of intervehicle communication was enhanced through dynamic time division multiple access (TDMA). The reliability and distributed property were enhanced through timeslot reservation and efficient broadcast mechanism. On this basis, multivehicle cooperation algorithms were designed based on intelligent vehicles, and cooperation scenes were implemented including platoon and overtaking. The experimental results proved the feasibility and reliability of the intervehicle communication protocol presented. Related Articles | Metrics

Select

Modeling of Maintenance Policy Choice Based on a Fuzzy DecisionMaking Grid Map WANG Jiayue1,ZHOU Binghai2 2010, 44 (09):  1217-1222.  Abstract ( 3321 )   Save A model of maintenance policy choice was built based on traditional decisionmaking grid map for building optimal equipment maintenance policy effectively by using fuzzy methods. A decisionmaking grid map was established with the mean downtime and the breakdown frequency as decision criteria. The maintenance policy represented by each region was decided, based on which, the membership functions of decision criteria were built and the degree of satisfaction of the choice maintenance policy related to equipment was evaluated by using a new Fuzzy Weighted Average algorithm. The fuzzy set of the satisfaction degree of maintenance policy cost was built and the new Fuzzy Weighted Average algorithm was used for the second time to decide the optimal maintenance policy. The experiment results show that the model established can solve the problems of the decisionmaking bias brought about by the method of the traditional decisionmaking grid, and that it is flexible and practical because it takes the weight and policy's cost into consideration. Related Articles | Metrics

Select

Application Research of Detecting Transformer Windings’ Deformation Based on Vibration Frequency Response Analysis SHAO Yuying1,XU Jian2,RAO Zhushi1,JIN Zhijian2,JIANG Yimin3,ZHOU Kai4 2010, 44 (09):  1223-1228.  Abstract ( 3611 )   Save Vibration frequency response analysis (VFRA) was used to test the same winding under the same state at different times. The winding of phase C was artificially made faults of pressboard missing and winding radial deformation. The experimental data show that the VFRA can effectively detect the faults of windings’ deformation and the results are repetitive. Compared with shortcircuit reactance measurement, the VFRA is more sensitive. Related Articles | Metrics

Select

Feature and Web Servicebased Sharing of Engineering Knowledgebase HU Yi,ZHOU Xionghui,LI Congxing 2010, 44 (09):  1229-1234.  Abstract ( 3253 )   Save To achieve knowledgesharing in collaborative product development, based upon open standards, a mechanism to implement the feature and Web servicebased sharing of engineering knowledgebase is proposed. In this mechanism, engineering database or expert knowledge acts as basic resources to construct engineering knowledgebase by the rulebased method, then the knowledgebase is wrapped and exposed to outside by Web services. Meanwhile, a method for part model transforming among heterogeneous Computer Aided X (CAX) systems is presented, which is the featurebased approach by which part models are transformed into platformindependent eXtensible Markup Language (XML) representations. Afterwards, based upon the publishing, finding and sharing approach of Web service, customers can search and choose appropriate Web services and send the XML representations of part models as inputs to gain relevant knowledge to evaluate part models, realizing efficient knowledgesharing. Related Articles | Metrics

Radiao Electronics, Telecommunication Technology

Select

Frequency Offset Estimation in LTE Uplink High Speed Train Scenarios NI Hao，REN Guangliang，BAI Yun,CHANG Yilin 2010, 44 (09):  1235-1240.  Abstract ( 4066 )   Save Abstract： A maximum likelihood (ML) frequency estimation algorithm for the long term evolution (LTE) uplink is proposed. By the quantitative analysis on the performances of the ML algorithm and the algorithm based on the phase difference between two training sequences (phase difference algorithm), a combined frequency offset algorithm is also proposed. The simulation results show that the proposed ML algorithm and combined algorithm cover a sufficient estimation range for the high speed train (HST) scenario compared with the phase difference algorithm. Moreover, the proposed ML algorithm is not vulnerable to the frequency hopping in the LTE uplink. At SNR=10 dB, when the number of users is smaller than 4, the two proposed algorithms can both provide 10-4, or even smaller, mean square error (MSE) of normalized frequency offset estimation. At the environment of only one user, the combined algorithm provides 5 dB improvement over the ML algorithm in performance. Related Articles | Metrics

Select

A Method of Intermediate Frequency Galileo E1 Signal Generating Based on MultiSatellites WU Zhongjie，MAO Xuchu 2010, 44 (09):  1241-1245.  Abstract ( 3698 )   Save A method to generate Galileo E1 intermediate frequency (IF) digital signal for simulation of Galileo signal based on multisatellites with BOC (1,1) modulation was presented. This Galileo IF digital signal can serve as reliable data resource in the research of development of software receiver and highsensitivity Galileo receiver based on weak signal processing. The simulink models of Galileo IF signal was designed according to signal generation module needed in signal generator. Then Galileo IF signal was generated by PRN code, BOC modulation, navigation data of multisatellites, and carrier and modulated noise model with adjustable intensity. The experimental results by signal processing with autocorrelation and signal acquisition show that Galileo IF signal with adjustable carriertonoise ratio and Doppler shift has all the characteristics of BOC modulation and real Galileo signal, and that it can be used in signal processing in software receiver. Related Articles | Metrics

Select

A Tracking Method for Weak GPS Signals Using Dual Kalman Filters and Bayesian Estimation ZHOU Guangyu，MAO Xuchu，LIN Qingen，CAO Yi 2010, 44 (09):  1246-1250.  Abstract ( 4098 )   Save A new method on GPS weak signal tracking based on dual squareroot Kalman filters and Bayesian Estimation was proposes. It uses a new model of Kalman filter to deal with code tracking and carrier tracking respectively. Bayesian estimation theory was introduced into this method to estimate the unknown navigation data, so that the bad effect brought by reverse of data bits is deeply alleviated. The simulation results show that the weak signal with carriertonoise ratio (C/No) as low as 19 dBHz can be well tracked by the proposed method. Related Articles | Metrics

Select

A Frequency Domain Equalization Algorithm for SingleCarrier Systems over Fast TimeVarying Channels LI Si，GUI Lin，XIONG Jian 2010, 44 (09):  1251-1255.  Abstract ( 3418 )   Save An iterative decision feedback frequency domain equalization algorithm for singlecarrier systems over fast timevarying channels was presented, referring to the intercarrier interference (ICI) cancellation schemes of multicarrier systems. The interference induced by fast fading was iteratively cancelled using a tentative estimation of the received signal obtained from linear equalization. The intersymbol interference induced by fast fading was treated as equivalent noise power during frequency domain equalization based on minimum meansquared error (MMSE) criteria. Simulations show that the proposed method using iteration and decisionfeedback can effectively lower the error floor in fast fading environment. Related Articles | Metrics

Select

Resource Allocation in RelayBased OFDM Networks with Proportional Fairness WU Youlong1,LUO Hanwen1,LIU Wei1,WANG Hailong2,ZHOU Xiaolin3 2010, 44 (09):  1256-1260.  Abstract ( 4050 )   Save A new scheme was proposed which adaptively allocates the resource in the downlink scenario of a cellular cooperative frequencydivision multiplexing (OFDM) networks. The allocation scheme mainly contains the subcarrier and power allocation both in base station and relay nodes. Two algorithms, strict rate proportional fairness and relaxed subcarrier proportional fairness, for subcarrier allocation were proposed. The first one aims to achieve perfect rate proportional among users, allocates the best subcarrier to the user with worst rate proportional fairness; the second one relaxes the rate proportional fairness into subcarrier proportional fairness so that it can avoid too many subcarriers being allocated to the user with bad channel gains. After the subcarrier allocation, power allocation based on waterfilling algorithm was employed to improve the throughput. The simulation results and analysis show that, both of the proposed algorithms can substantially increase the throughput, and achieve a fine proportional fairness. Related Articles | Metrics

Select

Sparse Channel Estimation for MBOFDM System Based on Superimposed Pilots ZHANG Xianyu，LIU Yulin，ZHANG Jianxin 2010, 44 (09):  1261-1265.  Abstract ( 4052 )   Save (Digital Signal Processing Laboratory, Chongqing Communication Institute, Chongqing 400035, China) Abstract： A novel sparse channel estimation algorithm was proposed based on superimposed pilots in MBOFDM UWB systems. The superimposed pilots were exploited to estimate the channel parameters. New cost function was then established based on generalized Akaike information criterion (GAIC) criterion to detect the positions of nonzero taps, by which the estimation dimension was reduced with improvement of the estimation performance. Finally, the CramerRao Bound (CRB) was analyzed. The simulation results show the proposed algorithm has excellent performance and that the variance approaches the CRB. Related Articles | Metrics

Select

A Lowcomplexity User Selection Algorithm for Multicell MIMO Employing Orthogonal SpaceDivision Multiplexing Lv Jing1,LUO Hanwen1,LIU Wei1,ZHANG Jing2 2010, 44 (09):  1266-1270.  Abstract ( 3608 )   Save A lowcomplexity user selection algorithm was proposed for multicell multipleinput multipleoutput (MIMO) system employing orthogonal spacedivision multiplexing (OSDM) with outofcooperativecells interference suppression. The algorithm iteratively selects users through greedy search. In each user selection step, the user who contributes most to the average cell capacity is added to the selected user set, and the number of activated users is adaptively adjusted to maximize the average cell capacity. The simulation results show that compared with the user selection algorithm in MIMO system employing block diagonalization (BD) with outofcooperativecells interference suppression, the algorithm proposed can achieve higher average cell capacity, and support more users with the same signaltonoise raitio (SNR) and interferencetonoise raitio (INR). Related Articles | Metrics

Electrotechnology

Select

Design and Simulation of Threephase Voltage Source Pulsewidth Modulation Rectifier System JIANG Yaqun1,YANG Li2,WU Xupeng3,1,CAO Libo1 2010, 44 (09):  1271-1275.  Abstract ( 3274 )   Save A system model of the threephase voltage source pulsewidth modulation rectifier (VSR) under threephase static coordinate axis was proposed, and the mathematical model under the rotating dq coordinate axis was derived. Then, the feedforward decoupling control method was introduced to control the threephase VSR system. Next, the VSR designing technology, such as proportionalintegral (PI) controller design, main circuit design and key parameter setting, was discussed in detail. Finally, a design instance of VSR was presented, and its simulation model was established with Matlab/Simulink simulation platform. By showing good performance of the VSR, the simulation results prove that the VSR system model, the control scheme and the design method are correct and effective. Related Articles | Metrics

Biomedical Engineering

Select

Electric Field Analysis of Pt/Ir Microelectrode Array for Visual Prosthesis SUI Xiaohonga,HAN Zhaolongb,SHAO Yibina,ZHOU Daib,REN Qiushia 2010, 44 (09):  1282-1286.  Abstract ( 4294 )   Save Finite element method was employed to simulate the electric field distributions of a Pt/Ir microelectrode array for opticnerve visual prosthesis. Spatial electric field distributions of microelectrodes with different lengths were analyzed under monopolar and bipolar microcurrent excitements. The effectiveness of the Pt/Ir microelectrode array was validated by an experiment on animals. According to the simulation results, when under a 100 μA current stimulation monopolarly and bipolarly, the maximum points of the electric density all locate at the interface of the Pt/Ir material and the insulation. And as the maximum electric field point being the center, the radius of the effective space under monopolar and bipolar stimulations is approximately 21 and 24 μm, respectively. Related Articles | Metrics

Atomic Energy Technology

Select

Tomographic Gamma Scanning Technique for Radioactivity Detection of Nuclear Waste Drum LIU Cheng1,WANG Dezhong1,QI Tunfeng2,LI Shouping2, WANG Chuan2,ZHANG Wen2 2010, 44 (09):  1287-1291.  Abstract ( 3701 )   Save The principle of tomographic gamma scanning (TGS) method for nondestructive assay of heterogeneous radioactive waste was described. An experiment of a 200 liter drum detection was conducted using the radioisotope 152Eu as the transmission source. A polar voxel representation was used, and the efficiency matrix was calculated by MCNP codes. The algebraic reconstruction technique and maximum likelihood expectationmaximization method were adopted for transmission and emission reconstruction to get the distribution of linear attenuation coefficient and radioactivity, respectively. The TGS results are obviously　better than segmented gamma scanning (SGS) results, fitting the real activity very well with a relative error less than 10%. The results indicate that the polar voxel representation and reconstruction algorithms are feasible. Related Articles | Metrics

Weapon Industry

Select

Trajectory Planning for Cruise Missile in ThreeDimensional Space Based on Improved Ant Colony Algorithm GAO Shouwei1,2,YANG Yeqing1,ZHANG Weidong1 2010, 44 (09):  1292-1296.  Abstract ( 4134 )   Save A method of trajectory planning in threedimensional space was proposed based on Improved Ant Colony Algorithm (ACA). The optimization object function of survival probability was transferred, thus the maximum problem of survival probability and the minimization problem of trajectory length could be integrated into one. The consideration of terrain and the constraints were combined with the searching algorithm to make the trajectory more rational and the searching more efficiently. The simulation analyses show that the method of trajectory planning in this paper is applicable and acceptable. Related Articles | Metrics

Select

Geomagnetism Compensation Based on Disturbance Analysis for Shipboard and Underwater Attitude Determination YE Ping,ZHANG Yanhua,ZHAI Chuanrun,ZHAN Xingqun 2010, 44 (09):  1297-1301.  Abstract ( 3888 )   Save An analysis of magnetic disturbance was made and the geomagnetism under different disturbance was discussed based on turntable tests. Geomagnetism compensation was also proposed by employing mathematic fitting to eliminate heading errors caused by fixed magnetic disturbance. The experimental results demonstrate that the fitting compensation can remove magnetic errors effectively and can provide stable heading with an accuracy of 2.00°. Related Articles | Metrics

Management Science

Select

Algorithm on Cross Docking Scheduling in Asymmetrically Uncertain Environment CHEN Jie,CHEN Feng 2010, 44 (09):  1302-1306.  Abstract ( 4096 )   Save Revised expected transportation time was used to calculate the optimum solution under a certain case, and the realistic solution and optimum solution under an uncertain case. The results were the compared respectively. In addition, the revised expectation algorithm and the heuristic algorithm based on revised expectation were proposed. Moreover, minimum makespan was used as the objective function to study the direct delivery logistics scheduling problem when transportation times were assumed to be asymmetrically uncertain. The results of the numerical experiment show that the revised strategy is effective and practical because of the consideration of asymmertry. Related Articles | Metrics

Engineering Mechanics

Select

Modified Twoslope Method of Nanoindentation ZENG Wei,SHEN Yao,WAN Haibo,ZHANG Ning 2010, 44 (09):  1307-1311.  Abstract ( 3803 )   Save Twoslope method, which is used to calculate the materials' elastic modulus and hardness by using of nanoindentation forcedisplacement curves, was modified by the introduction of two correction parameters that account for the effect of the two factors that influence the accuracy of this method most severely. The values of the correction parameters indentation on fused silica with Berkovich indenter were obtained by FEM simulation and comparison between the experiments and standard values of fused silica. Good agreements between the values from the two ways demonstrate the capability of the modified twoslope method, and the insensitivity of the twoslope method to the wear of the indenter tip. Related Articles | Metrics

Communication and Transportation

Select

Control System Design for Selfpropelled Model of a New Concept Submerging and Surfacing Platform PU Hao,FENG Zhengping,YI Hong 2010, 44 (09):  1312-1316.  Abstract ( 3654 )   Save Hardware and software design for selfpropelled model control system is introduced, of which upper and lower computers are used on the shore and model; communication is established through wireless local area network (LAN); servos and actuators are driven by the sophisticated programmable components；a variety of sensors and alarm equipment are equipped on board; the software is written with Matlab based on hybrid programming. The result shows that the selfpropelled model designed can reduce the workload involved in development of both hardware and software and improve the reliability of the system. Openloop test result shows that the system is versatile, highly extensible and easy to be manipulated, reflecting the maneuverability of the new concept submerging and surfacing platform. Related Articles | Metrics

Automation Technique, Computer Technology

Select

Statistical Process Monitoring of Autocorrelation Data from Multistage Processes WAN Song，LI Yanting，YU Fucheng 2010, 44 (09):  1887-1891.  Abstract ( 3341 )   Save An effective multivariate process control charts for autocorrelated data from multistage processes was established, and the formula for calculating its average run length was given by combining statespace models and statistical process control methods. The correctness of the formula was verified by Monte Carlo simulation. Finally, the new method was illustrated with one real example to demonstrate the implementation steps. The results show that in control the chart has low alarm rate, while out of control it has high alarm rate. Related Articles | Metrics