Table of Content

28 July 2010, Volume 44 Issue 07 Previous Issue    Next Issue

Automation Technique, Computer Technology

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A New GMPHD Filter Algorithm for Multiple Maneuvering Targets Tracking HAO Yanling1,MENG Fanbin1, 2,WANG Suxin2,SUN Feng1 2010, 44 (07):  873-0877.  Abstract ( 4131 )   Save Considering the traditional data association algorithm of multiple maneuvering targets tracking being of hard constraint condition, lower estimated accuracy, and higher computational complexity, a non data association tracking algorithm based on the random set theory was proposed. Since the proposed algorithm integrates the both advantages of Gaussian mixture probability hypothesis density (GMPHD) filter and current statistical mode1, avoids the difficult problem of data association, it is able to deal with multiple maneuvering targets tracking effectively. A simulation experiment was performed in the complex environment with clutter, miss detection, false alarm, dense, and cross targets. The simulation results show that the proposed algorithm has higher tracking accuracy and more steady tracking performance. Related Articles | Metrics

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Research on Product Configuration Rules Extraction Based on Variable Precision Rough Set and Incremental Updating GENG Xiuli,ZHANG Zaifang,CHU Xuening 2010, 44 (07):  878-0882.  Abstract ( 3796 )   Save Aiming at the problem that product configuration rules extraction method based on traditional rough set has poor noisetolerance capability, a variable precision rough set method was used to construct configuration decision table according to product design case data, to carry out relative attribute reduction based on decision class lower approximation and value reduction based on corevalue attributes through setting classification precision, and then acquire effective configuration rules based on support degree. Considering the effect of design case data addition on configuration rules extraction, an incremental updating method was proposed to update product configuration rules based on confidence degree, and to deal with the relationships of repetition, inclusion and confliction between newly added configuration rules and the original configuration rules. A case study of horizontal directional drilling configuration rules extraction was presented to illustrate the feasibility and effectiveness of the proposed method. Related Articles | Metrics

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Research on Improvement and Simplification of ID3 Algorithm ZHU Haodong 2010, 44 (07):  883-0886.  Abstract ( 3778 )   Save For the shortcoming that ID3 algorithm tends to choose attribute which has many values, attribute importance was introduced to improve ID3 algorithm. Next, according to the character of information gain, the improved ID3 algorithm was simplified to reduce the complexity of computing information gain by the convex function. Through experiment testing, the optimized ID3 algorithm can spend much less time to construct the high accurate decision tree and this decision tree has less average leaves. Related Articles | Metrics

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Trajectory Planning with Least Wrench Error for a Generalized Load Simulator WANG Xuanyin，WU Lebin 2010, 44 (07):  887-0891.  Abstract ( 3623 )   Save This paper studied on the trajectory planning for a generalized load simulator (GLS), which works with a structured spatial compliant mechanism. Math model of masterslave dualparallel GLS system was established. An optimal trajectory planning method was proposed for the purpose of least wrench error. This method decomposes the optimal trajectory into static optimal trajectory and dynamic complementary trajectory. The former determines the mapping relation from wrench to twist via Hook’s law. The latter, which is used to eliminate the influence of iterative load, is computed by the linearized dynamic equation of the former one. The results of simulation show that this method is capable of generating load trajectory with high precision, and the wrench error is limited within 0.9‰. This work is of great importance to practical engineering. Related Articles | Metrics

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HardwareintheLoop Simulation Based xPC Target and Reflective Memory Network YANG Feihong,WANG Xuyong,TAO Jianfeng,MIAO Zhonghua,LUO Baoying 2010, 44 (07):  892-0896.  Abstract ( 4162 )   Save In order to solve the problems of rapid prototyping and realtime communication between distributed nodes in the system of hardwareintheloop (HIL), a resolution of combination of xPC target and reflective memory network (RMN) was proposed. A design procedure of HIL test and the key technique of building realtime network using RMN were introduced under the environment of xPC target. Performance measurements on singlepoint xPC target and multipoint xPC targets connected with RMN were also carried out. Through the application in certain terminal guidance simulation system, the “xPC + RMN” based solution is proved to be suitable for the development of HIL. Related Articles | Metrics

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Numerical Simulation of the Temperature Field in Kinescope Glass Shell Forming Process SUN Qiang1,CUI Yongsheng2,CUI Shubiao1,ZHOU Huamin1 2010, 44 (07):  897-0901.  Abstract ( 4219 )   Save An integrated cooling simulation method for the temperature field of the panel during the forming process was proposed. The simulation system for the optimization of processing parameters and inmold cooling system structure design was developed. A finitedifference method based local onedimensional transient analysis in the thickness direction is adopted for the panel part. A threedimensional, boundary element method is used for the numerical implementation of the heat transfer analysis in the mold region. The part and mold analysis are coupled so as to match the temperature and heat flux on the glassmold interface. This paper presented an integrated and coupled numerical model for analyzing the panel cooling process. The numerical results are in good agreement with the experimental ones. Related Articles | Metrics

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A New Multi-view Face Tracking Algorithm MA Bo，ZHOU Yue 2010, 44 (07):  902-0906.  Abstract ( 4346 )   Save This paper proposed a new algorithm based on subspace model for robust multiview face tracking under complex environment. It combines the offline face models and online selflearning models. The paper also presented new selfadaptive particle filter algorithm to track face. The experiments demonstrate that this algorithm can handle multiview and multiscale face tracking steadily in complex environment. Related Articles | Metrics

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An Original Video Differential Energy Watermarking Algorithm Based on FSM Model FENG Jiaqi1，JIANG Xinghao1,2,SUN Tanfeng1,2,LIN Zhigao1,LU Huan1 2010, 44 (07):  907-0910.  Abstract ( 3764 )   Save In order to produce interframe correlation and efficiently detect timedomain synchronous attack, a differential energy watermarking (DEW) algorithm was improved and a finite state machine (FSM) model was introduced. The experiments show that the watermark keeps robust to common intraframe disturbance such as noise while its fragility to malicious interframe attack provides it effective detectability against synchronous attack. In addition, it performs well in invisibility and algorithm security. Related Articles | Metrics

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Image Classification Using Modified ISOMAP Method WEI Xian,LI Yuanxiang,ZHAO Haitao,TUO Hongya,XU Peng 2010, 44 (07):  911-0915.  Abstract ( 4359 )   Save The classical ISOMAP（isometric feature mapping，ISOMAP） method developed on reconstruction principle may not be optimal from the classification viewpoint. Besides，it is prone to suffer from the noise and the range of the neighborhood. In order to resolve these problems, a novel method called KIMDISOMAP for dimensionality reduction was presented. Firstly, a modified image euclidean distance is proposed and used to find the suitable neighborhood. Then, direct linear discriminant analysis (Direct LDA) is used to replace multidimensional scaling (MDS). Compared with ISOMAP, the experiments on face recognition show that KIMDISOMAP enhances the ability of classification and extends the range of the neighborhood. In addition, the KIMDISOMAP obtains a better performance than other algorithms for images classification with small noise and geometrical deformation. Related Articles | Metrics

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Research on Bifurcation and Nonlinear Stability of an Improved TimeDelayed Dual Model in Internet Congestion Control LIU Yuliang1,2，ZHU Jie2 2010, 44 (07):  916-0920.  Abstract ( 4012 )   Save Based on Hopf bifurcation theory, an improved timedelayed dual model was proposed in Internet congestion control in order to make the stable domain enlarged. The modified model’s dynamic characteristics such as bifurcation condition, bifurcation direction and bifurcation periodic solution are all derived as the communication delay changes. The study shows that the novel model’s nonlinear stability can be described mathematically by three expressions. This paper’s creativity lies in the model’s improvement and its stability’s quantitative description, and it gives the necessary theoretical foundation on designing effective Internet congestion control protocols or algorithms. Related Articles | Metrics

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A Dynamic Framework for TargetGrouping Based onClustering Data Streams LONG Zhenzhen1，2，ZHANG Ce2，WANG Weiping3，ZHANG Zhengwen4 2010, 44 (07):  921-0925.  Abstract ( 3679 )   Save In order to solve the dynamic targetgrouping problem, a framework based on clustering data streams was presented, which can be divided into two parts: online part and offline part. In online part, the concepts of a pyramidal time frame and a temporary storage structure are used; in offline part, CNM algorithm is used to cluster the suitable data. After the experiment, the results show that this framework has good equilibrium between accuracy and efficiency. Related Articles | Metrics

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Identifying the Crack of Silicon Solar Cells Based on Matlab Image Processing LIU Xiaohui,XU Lin,XIAO Chenjiang,CAO Jianming,XIAO Jiao 2010, 44 (07):  926-0930.  Abstract ( 4399 )   Save Aiming at the measure problem of crack of silicon solar cells, an infrared noncontact detection method was used. The electroluminescence image of silicon solar cells was captured by CCD camera. Image preprocessing, image segmentation, feature extraction and image identification were analyzed based on Matlab image processing. The result proves that, using the principle, crack of silicon solar cells can be detected. Related Articles | Metrics

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Hybrid Data Compression Algorithm Based on BS-PLOT for Remote Monitoring of Construction Machinery LI Yanming,L Huijuan,YUAN Jin，LIU Chengliang 2010, 44 (07):  931-0934.  Abstract ( 3587 )   Save According to the condition signal’s feature, this paper proposed a hybrid data compression algorithm based on the backward scope (BS) and piecewise linear online trending (PLOT) algorithm. Within the maximum time limit, the algorithm uses BS to estimate the data stabilization, then adopts PLOT to compress the fluctuant data, considering the time attribute of data and the detection of outliers in noisy environment. This method was applied to the remote monitoring system for tower crane. The result indicates that the proposed method with antidisturbance property can improve the compression efficiency and transmission efficiency. Related Articles | Metrics

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Application of WPT Method for Improving the Measurement Precision of Impulse Current Waveform YUAN Haiyan1,FU Zhengcai1CHEN Yongbin2 2010, 44 (07):  935-0939.  Abstract ( 3773 )   Save The wavelet packet transform (WPT) method was proposed to denoise for the measured wave in the impulse current test. The four denoising methods, including the WPT method, the Fourier transform, the curve fitting and the wavelet transform method, were used to denoise for the same waveform with noise. Also, the denoised waveform parameters were calculated. The research indicates that the noise frequency has no impact on the denoising results. The error of waveform parameters denoised with WPT is the least. The influence on the wave front is little and the magnitude of denoised wave is almost the same with the standard wave. On the contrary, the error of denoised wave with curve fitting is the maximal. The investigation on the measured wave verifies that WPT is the most precise and practical method. Related Articles | Metrics

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Trajectory Planning and Control for Robotic yoyo YUAN Dehu1,2,JIN Huiliang1,MENG Guoxiang1，FENG Zhengjin1 2010, 44 (07):  940-0945.  Abstract ( 4108 )   Save This paper presented a general approach for planning trajectories for cyclic dynamic systems, and demonstrated its application for robotic yoyo playing. The approach is based on the return map parameterization using intermediate states of the system. The height of the robot arm when the yoyo arrives at the bottom is selected as the intermediate state. By solving the optimization problems during each phase of a cycle, a reference trajectory, a nominal control for the robot and the corresponding return map of the object are generated simultaneously. The method can also be applied to other similar periodic dynamic systems. Related Articles | Metrics

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A Pedestrian Detection Method Based on Laser Scanner and Camera QIAN Huijiaa,YANG Minga,LI Haoa,WANG Chun xiangb 2010, 44 (07):  946-0950.  Abstract ( 4594 )   Save For urban traffic safety, a camera and laser scanner codetection method was presented. A proper ROI (region of interests) can be located based on the perspective transform between the camera coordinate and laser scanner coordinate, and a method of synchronization is induced from dead reckoning. In the process of laser scanner’s cluster, a simple rule is proposed for object segmentation based on pedestrian’s width. It can separate pedestrian side by side effectively. Then, vision based method is used for identification of pedestrian. First, a method of pretreatment for ROI is introduced according to the characteristics of the symmetry of pedestrian’s edge. Second, a template matching method based on Hausdorff distance is applied to match the upperbody template by laser scanner’s distance refinement. The experimental results are relatively ideal. Related Articles | Metrics

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Study on Hydrogen Safety of Fuel Cell Engine Based on Fuzzy Fault Tree QUAN Ruia,QUAN Shuhai a,b,HUANG Liang b,CHEN Qihong b 2010, 44 (07):  951-0956.  Abstract ( 3940 )   Save According to the safety and reliabilty performance of fuel cell engine, the requirement and influence factors of its hydrogen safety and electrical safety were analyzed, and mainly from the point of hydrogen safety, the fault tree model of hydrogen leak was set up. Considering the fuzzy and uncertain probability of each elementary and middle event, fuzzy theory and fault tree analysis were combined to express each probability, and the fuzzy probability of top event was figured out, then the fuzzy importance of each elementary event was analyzed by fuzzy number median methods,the weakness of its safety and reliabilty was presented, finally several improvement measures were put forward. The results prove that the fuzzy fault tree adopted in this paper is more applicable and effective than traditional fault tree analysis, which can provide a guidance for enhancing the reliable and secure design of fuel cell engine in the future. Related Articles | Metrics

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Autonomous Underwater Vehicle Improved Surface Controller and Semiphysical Simulation Lv Chong，PANG Yongjie，WANG Bo，ZHANG Lei 2010, 44 (07):  957-0961.  Abstract ( 4056 )   Save S surface controller is proved to be effective in application to the motion control of autonomous underwater vehicle (AUV). However, it is difficult to adjust the control parameters manually. Choosing the optimum parameters for the controller of a certain AUV is an important problem. Thus, a modified particle swarm optimization (MPSO) algorithm based on immune theory and nonlinear digression strategy of inertia weight was proposed to optimize the control parameters of a certain AUV. A semiphysical simulation system for AUV was presented as a platform to verify the proposed control method. And its structure was described. The simulation results indicate that the semiphysical simulation platform is helpful, the optimization algorithm has good local and global searching abilities, and the control method is feasible in application to AUV. Related Articles | Metrics

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FPGA Implementation of Dynamic Neural Network for Support Vector Machines LIU Han,YIN Song,LIU Ding 2010, 44 (07):  962-0967.  Abstract ( 4480 )   Save A new FPGA hardware implementation approach of dynamic neural network for support vector machines was provided and researched.The structure of dynamic neural network for least square support vector machines (LSSVM) was proposed. The architecture design of dynamic neural network for LSSVM based on VHDL language was also performed. The experiments of classification and regression for LSSVM were achieved on XILINX SPANT3E series FPGA. The experimental results show that it is effective to complete the LSSVM classification and regression based on presented method. Compared with the existing methods based on software implementation or analog device implementation, this approach has better convergence rate and better flexibility. Related Articles | Metrics

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Approaches to Resisting LengthBased Attack CHEN Le，CAO Zhenfu 2010, 44 (07):  968-0974.  Abstract ( 3476 )   Save This paper proposed the key exchange protocol based on Thompson’s group, which controls the process of generating words, and designed experiments to show that the protocol can resist the lengthbased attack. Moreover, because the lengthbased attacks on other noncommutative groups are similar to the one on Thompson’s group, it suggests that the approaches can be applied to any other noncommutative group to resist the lengthbased attack on that group. Related Articles | Metrics

Electrotechnology

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The Measurement Positions Optimization in Extrapolation of Steel’s Magnetic Field Based on Particle Swarm Optimization Algorithm LIAN Liting,XIAO Changhan,LIU Shengdao,YANG Mingming 2010, 44 (07):  975-0979.  Abstract ( 3593 )   Save Aiming at the problem that the condition number of coefficient matrix is very large after the equation discretization when extrapolating the steel’s magnetic field， a new method was introduced. It can get optimal measurement positions according to magnetic field calculations and mesh of the ferromagnetic object and then the optimal measurement positions can be easily got by particle swarm optimization algorithm. The new method not only optimizes the positions, but also reduces the number of points and receives good results. In order to validate the positions, two different sets of measurement positions were used to extrapolate the sheet steel’s magnetic field. The good results explain that the conclusion is reasonable. Related Articles | Metrics

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Development and Calibration of an Impulse Magnetic Field Measurement System REN Xiaoming1,2,FU Zhengcai1,HUANG Xiaohong2,SUN Wei1 2010, 44 (07):  980-0983.  Abstract ( 3357 )   Save In order to evaluate the impulse magnetic field distribution in buildings struck by lightning or nearby lightning strokes, a set of measuring system composed of selfmade magnetic detecting coil and fiber transmitting system was developed. The sensitivity coefficient of the fiber transmitting system was calibrated by sinewave generator. The output of an 8/20 μs current generator is connected with the single turn circular coil whose diameter is 0.3 m to compose the magnetic field generator. The detecting coil is fixed in the center of the single turn coil for calibration. The results show that the developed system can measure the impulse magnetic field effectively and the B/U calibrated coefficient error of the system is less than 3%. Related Articles | Metrics

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Equilibrium Model for Electricity Market Including Energy Saving and Emission Reduction Constraints YANG Jianlin1，YAN Zheng1，YU Guoqin2，LIN Yi2 2010, 44 (07):  984-0988.  Abstract ( 3493 )   Save An oligopolistic model, including the energy saving and emission reduction constraints, was proposed. The locational marginal prices associated with generator buses are composed by four components: the marginal energy cost, the capacity opportunity cost, the energy saving and emission reduction opportunity cost and the ramp rate opportunity cost. As illustrated by the case study, in the oligopolistic environment, the GenCos with high energyconsumption rate and high emission rate have to reduce their bidding prices to obtain more revenues, while the GenCos with low energy rates and low emission rates can obtain more revenues by increasing the bidding prices. Besides, in the multiperiods scenario, the energy consumption amount (emission amount) often shift from the valley load periods to the peak load periods. Related Articles | Metrics

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Field Analysis of Tubular Permanent Magnet Linear Synchronous Motor with Radial Magnetization ZHAO Jinghong，ZHANG Xiaofeng，ZHANG Junhong，GAO Wei 2010, 44 (07):  989-0993.  Abstract ( 4290 )   Save Based on scalar quantity magnet of tubular reference frame with separated variables, an analytic magnetic field calculation method was introduced, which is a way to work on the tubular permanent magnet linear synchronous motor with radial magnet. An elaborate academic analysis to magnetic field distribution of nonslotted motor was conducted, the result of which shows the axial and radial slot magnetic distributions. To the slotted motors, Carter coefficient was introduced and amendatory expressions of the analytic result were shown, meanwhile the thrust force of the motor was calculated analytically. Then, finite element analytic method was used to testify the calculation of the magnet and the force. It can be concluded that there is almost no difference between the error results of the above two methods. So it is accurate and practical to calculate the magnetic field using the method based on scalar quantity magnet of tubular reference frame with separated variables, as well as the thrust force. Related Articles | Metrics

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Study on Thermodynamic Characteristics and Experimental Analysis of Molten Carbonate Fuel Cells LIU Aiguo,WENG Yiwu,YU Lijun 2010, 44 (07):  994-0999.  Abstract ( 3454 )   Save This work presented a onedimensional mathematical model for molten carbonate fuel cell(MCFC) based on mass, energy and momentum conservation principles and thermodynamic properties. Using the VR modeling technique the partial differential equations can be changed to ordinary differential equations which meet the quick simulation. The electrochemical reactions are considered in the model, and the characteristics of distributed parameters are shown. Some experiments were carried out, and the performance of the MCFC at a certain condition was analyzed using the model. A good agreement between the simulation and experimental results is presented, which shows the feasibility of using the volumeresistance characteristic model to reflect the molten carbonate fuel cell characteristics. Related Articles | Metrics

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Fault Currents of the Doubly Fed Induction Generator with Constant AC Excitation ZHANG Luhua,GUO Jiahu,CAI Xu,CAO Yunfeng,CHENG Mengzeng 2010, 44 (07):  1000-1004.  Abstract ( 3609 )   Save This paper systematically analyzed the dynamic responses of doubly fed induction generator(DFIG) stator and rotor currents when threephase short circuit occurs at stator terminals, and also presented a new approach in which the DFIG under fault condition is equivalent to a rotor excited induction machine running in a steady state and a squirrelcage induction machine subjected to threephase short circuit, to get the fault currents. Space vector analysis was introduced to get the analytical expression of fault currents. The maximum rotor and stator short circuit currents as well as the times when they appear were proposed. Furthermore, main components of the short circuit currents and their relations were presented. Finally, all above results are validated in Matlab/Simulink. Related Articles | Metrics

Mechanical Engineering

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Model Reduction of High Speed Onoff Solenoid Valve and Experimental Validation ZHANG Minmin1,CHEN Li1,HUO Yi1,XIE Xianping2,LU Shun2 2010, 44 (07):  1005-1009.  Abstract ( 3914 )   Save To reduce the complexity and increase the calculation speed for nonlinear model of high speed onoff solenoid valve, the energybased model reduction algorithm was used. Considering the multidomain coupling characteristic, the concept of subsystem activity index (SAI) was proposed to evaluate the contribution of the subsystems. The full model was established and reduced in Matlab/Simulink environment and validated by a testbench experiment. With the error less than ±5%, the model built in this paper is accurate for further study. Related Articles | Metrics

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An Improved Algorithm of Mary SpreadSpectrum Communication ZENG Zhibinga,ZHUANG Yiqia,XIANG Xinb 2010, 44 (07):  1010-1013.  Abstract ( 3573 )   Save An improved Mary spread spectrum communication algorithm was proposed based on the problem that Mary spread spectrum adopting code phase shift keying (CPSK) needs synchronization information. The scheme is easy to realize because all spread spectrum codes comes from one SS code and its reverse order sequence. The scheme adopts BPSK modulation based on polarity modulation of PN in inphase branch, and CPSK modulation based on phase modulation of PN code in orthogonal branch. The system has the advantages which can achieve carrier synchronization accurately and fleetly, but rather offer additional synchronization resource. The simulation results demonstrate that the algorithm is effective in improving the utilization ratio of system resources. Related Articles | Metrics

General Industrial Technology

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Performance Analysis of a Two-Loop Closed Queue Network Model in Semiconductor Assembly System LI Na1,JIANG Zhibin1,ZHENG Li2,ZHUANG Caihua1 2010, 44 (07):  1014-1018.  Abstract ( 3738 )   Save This paper described a system in semiconductor assembly line in which two type of carts cycling around. It is a typical twoloop closed production line. The mathematical model was constructed considering the stochastic character of the line. An approximation algorithm based on the overlapping decomposition philosophy and the iterative procedures to estimate the throughput were proposed. The accuracy of the estimates was studied by the experiments and the real case and it proves that the approximation method is effective. Related Articles | Metrics