Table of Content

31 August 2010, Volume 44 Issue 08 Previous Issue    Next Issue

Automation Technique, Computer Technology

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Rule Based Dynamic Spatial Scheduling for Hull Block Construction ZHANG Zhiying1,XU Chen1,MAO Zujie2,LIU Jianfeng2 2010, 44 (08):  1019-1025.  Abstract ( 3799 )   Save The dynamic spatial scheduling method based on rules was proposed to deal with scheduling problem existing in hull block construction. The method combines workshop construction planning and dynamic adjustment. Firstly, similarity principle based on hull block’s projective shape is used to develop the block construction planning, and response rules aiming to dynamic events are built to realize the automatic management. Many dynamic events are classified and direct effects, adjustment approaches and relevant response rules are given. Three events, the emergent block inserted, task cancelled and equipment failure, are taken as examples to illustrate the process of whole method. Finally, the proposed schedule and adjustment method were proven feasible and effective through the simulation. Related Articles | Metrics

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Design of the Connection Mechanism for a Novel Selfreconfigurable Modular Robot JIANG Dongsheng，GUAN Enguang，FU Zhuang，ZHAO Yanzheng 2010, 44 (08):  1026-1030.  Abstract ( 3670 )   Save The lattice selfreconfigurable modular robot has attracted more and more attention for its excellent flexibility in connection and separation movements. A novel selfreconfigurable robot module, called MLattice, was presented. A genderless pinslotbased connection mechanism was introduced. The static and dynamic experiments indicate that the selfreconfiguration connection can be accomplished by the mechanism smoothly and rapidly. The time cost of the connecting movement is approximately 2 seconds and the strength of connection between the two mechanisms is capable of over 50 N axial load. Related Articles | Metrics

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(t, k, l)-Threshold Proxy Signature Without Random Oracle ZHANG Hai1,DONG Xiaolei1,CAO Zhenfu1,CAO Feng2 2010, 44 (08):  1031-1036.  Abstract ( 3449 )   Save To generalize the concept of (t,l)threshold proxy signature scheme, this paper proposed a (t, k, l)threshold proxy signature scheme, in which any k or more proxy signers in a designated proxy group of l members can cooperatively issue a proxy signature and this scheme can also tolerate at most t-1 corrupted signers. The security model of existential unforgeability for the threshold proxy signature scheme was presented, then a (t +1, 2t +1, l)threshold proxy signature scheme based on the hardness of CDH problem was proposed, and the existential unforgeability was proved under this security model. At the same time, this scheme has the properties of distinguishability and proxy protected. Related Articles | Metrics

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A Method for Optimizing the Combinational Kernel of Support Vector Machine Classifier YANG Xu,YANG Xin,XIONG Huilin 2010, 44 (08):  1037-1041.  Abstract ( 3418 )   Save To solve the problem of model selection for support vector machine(SVM) classifier, a featurespacebased class separability measure(FCSM) was proposed. With this measure, the combination coefficients of multiple Gaussian functions were optimized. Compared with the kernel matrix evaluation measure (FSM), the new measure has fewer limitations in the application of kernel optimization, and has better theoretical guarantees. The experimental results show that the proposed algorithm outperforms the crossvalidation method, the radius margin bound method and the FSM based method, and moreover, it achieves better performance on SVM classifier with the optimal kernel selected from a wider range of function set. Related Articles | Metrics

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A Road Following System for Intelligent Vehicles Based on Active Vision ZHANG Yutenga,YANG Minga,WANG Chunxiangb 2010, 44 (08):  1042-1045.  Abstract ( 3720 )   Save The active vision method was used in the control of intelligent vehicles on urban environment roads to expand the field of view of onboard camera. The angle of the pan&tilt unit is set according to the relative position between the lane and the vehicle to keep the lane in the middle of the image. The corresponding relationship between the vehicle coordinate system and image coordinate system was analyzed and calculated in real time. The conclusion that the active vision system has a higher roadtracking accuracy and less imagelost rate is shown in the comparison experiments between the active vision system and the traditional vision system. Related Articles | Metrics

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Microassembly Force Measurement Using Blur Image Analysis JIANG Ruyi,LIU Hongtao,HU Wen,LIANG Qinghua,WANG Shigang 2010, 44 (08):  1046-1050.  Abstract ( 3249 )   Save A new approach based on machine vision to measure the force during microassembly was proposed. After the acquisition of outoffocus blur image of microgripper under force, with the established model of the relationship between the force and the outoffocus blur parameter, the problem of force measurement is transformed into that of blur parameter identification. A coarsefine blur identification method is then put forwarded, where microgripper’s bending curve is used for curve fitting the blur parameters. The coefficient of the fitted curve has a direct relationship with the force. The simulation results show this method’s validity. Related Articles | Metrics

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ChannelRouting Joint Optimization Algorithm for Wireless Mesh Networks SHAO Jinming,HE Chen，JIANG Lingge 2010, 44 (08):  1051-1056.  Abstract ( 3369 )   Save The optimization problems for transmission performance of wireless mesh networks (WMN) focus on the issues as system throughput, average delay and transmission fairness, etc. It is an NPhard problem. This paper proposed an iterative optimization algorithm based on heuristic and primaldual algorithms which optimize the system throughput under the constraints of channelradio and link capacity. It also analyzed the convergence of the proposed algorithm. The simulations show that this algorithm can largely increase the system throughput of WMN. Related Articles | Metrics

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A Fast Search Strategy Based on Image Matching of Computer Screen YANG Guang,MAO Hongyu,TIAN Di,LI Jun 2010, 44 (08):  1057-1060.  Abstract ( 3609 )   Save This paper put forward a kind of fast search strategy applicable to the computer screen image. Firstly, the moving range of the window containing the target image is determined, and the relative coordinates of the target image are calculated to reduce the search space. In addition, the space coordinates of known matching points are statistically classified, and the search priority is defined according to appeared probability of the target point, to build a learningstyle search algorithm. The test results show that, for the computer screen image, the algorithm has significant advantages in computing speed and matching accuracy. This method has been successfully applied in the national largescale scientific instruments work condition monitoring system. Related Articles | Metrics

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Image Preprocessing of Echocardiographic Virtual Endoscopy System XUE Haihong1,CHEN Binjin2,SUN Kun1,3,YU Jianguo2,WANG Weiqi2 2010, 44 (08):  1061-1067.  Abstract ( 3877 )   Save Virtual endoscopy （VE） is a new visualization method using 3D image data sets to simulate the tracks of a conventional endoscope. By using virtual reality computing techniques and visualization in scientific computing techniques, it can assist with the interpretation of 3D data of the heart in space and make it possible to ‘dive’ into the 3D model of the heart. A speckle reduction technique based on the homogeneous mask area filtering algorithm was applied to suppress the speckle noise, and then the denoised image was further processed by using the brFCM method to get an initial segmentation, after that, an integrated technique based on the combination of the multiscale analysis and texturebased contrast was used to obtain the final segmentation. The experimental results show that the proposed method can eliminate the speckle noise well and preserve the edge details of ultrasound images simultaneously and is helpful for visualization of 3DE virtual endoscopy. Related Articles | Metrics

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A Hybrid Ant Colony Optimization Method for Scheduling Jobs on Parallel atch Machines GUO Chengtao,JIANG Zhibin 2010, 44 (08):  1068-1073.  Abstract ( 4083 )   Save In wafer fabrication system, the performance measures of batch processing machine’s schedule have significant impact on plant performance because these machines have time consuming feature. Two phases, batches forming and batches scheduling, are needed to schedule batch machines. The difficulties lie in the former phase because of the dynamic arriving time of jobs. A hybrid ant colony optimization (ACO) algorithm was proposed, which batches the jobs by using the global and parallel searching mechanism of ACO, and schedules these batches by BATC algorithm.With respect to a due datebased objective (minimizing total weighted tardiness), the proposed algorithm was applied to schedule parallel batch process machine with incompatible job families. The performance of the hybridACO algorithm was evaluated and compared with that of other approach through simulations, and the results show that the proposed algorithm can generate quite effective and practical schedule. Related Articles | Metrics

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Feature Lines Extraction from Triangular Mesh Based on MorseSmale Complex QIU Yanjie,ZHOU Xionghui,LIU Wei 2010, 44 (08):  1074-1078.  Abstract ( 4020 )   Save This paper presented a method to extract feature lines from the triangular mesh based on the MorseSmale (MS) complex. Firstly, the MS complex is constructed with curvedness as the indicator function. Critical points and decending/ascending arcs of the complex compose the initial group of feature lines. Then the significance factors of the feature lines are defined and less important features are removed by a simplification process. The computational results show that this method can automatically and efficiently extract the connected feature lines. Related Articles | Metrics

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Movement Performance Analysis of Sixwheeled Lunar Rover in Virtual Reality Environment YANG Yanchun,BAO Jinsong，JIN Ye 2010, 44 (08):  1079-1083.  Abstract ( 4284 )   Save To simulate the lunar rover traveling on lunar environment, virtual reality technology was used to create a lunar rover simulation environment, and in the environment a sixwheeled lunar rover’s physical model was set up, a numerical method was given to solve the physical model. Thus, the rover’s movement performance analysis was achieved by running the virtual sixwheeled lunar rover on the virtual moon’s surface environments. By comparing the real lunar rover prototype test results and simulation test results, the effectiveness of the virtual simulation was verified. The high fidelity simulation of lunar rover brings an effective auxiliary tool for its design. Related Articles | Metrics

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Approximate Merging of a Pair of Cubic Uniform Bspline Curves with Shape Parameters QIN Xinqiang，YUE Li，HU Gang，LI Kai 2010, 44 (08):  1084-1088.  Abstract ( 3431 )   Save In order to develop the basic theory of cubic uniform Bspline curve with multiple shape parameters, the approximate merging of existing curve design was researched. By combining the fitting method of curves with the theory of the general inverse matrix, the explicit formula of control points of the merged cubic uniform Bspline curve with multiple shape parameters can be given directly. Eventually, some merging examples were discussed and the errors of approximate merging were also given. The experimental results illustrate that the proposed method not only has a good merging effect, but also is easy to implement and simple for error estimation. Related Articles | Metrics

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Background Removing of Slap Fingerprint Images Based on Frequency Domain Analysis LI Yanmiao1，ZHANG Yongliang2，HUANG Yaping3，XIAO Gang2，LIN Jing2 2010, 44 (08):  1089-1093.  Abstract ( 3378 )   Save To separate the background from the foreground of slap fingerprint images quickly and accurately, an efficient algorithm based on frequency domain analysis was presented：① the coarse separation of foreground from the background based on threeorder cumulant; ② the binarization enhancement based on optimal threshold segmentation of gray histogram distribution; ③ the removal of nonfingerprint texture region based on frequency domain analysis and two decision rules; ④ the region combination based on the center nearest neighbor rule. The experimental results show that the algorithm, which is proven effective by the given examples, has a faster processing speed and superior precision. Related Articles | Metrics

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Feature Recognition for Freeform Sheet Metal Parts Using Curvature Analysis of NURBS ZHANG Chunjie,ZHOU Xionghui,LI Congxin 2010, 44 (08):  1094-1099.  Abstract ( 3322 )   Save This paper presented an approach to recognizing geometric features from freeform surface models of sheet metal parts. It consists of three steps: region segmentation of surfaces, domain independent protrusion/depression detection and recognition of geometric features for sheet metal forming domain. The input geometry data is based on an IGES CAD model and the surface can be represented by trimmed NURBS surfaces. Symbolic computation is used to analyze surface curvature and segment them into curvature regions (CRs). Then sets of connected CRs with particular geometry and topology which have highlevel engineering meanings are recognized as features by a rulebased approach. Two case studies are presented to verify the feasibility of the developed method. Related Articles | Metrics

Radiao Electronics, Telecommunication Technology

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Application of Inclined and Rotating UV Lithography in Preparation of Microneedles JIANG Hongmin,ZHU Jun,CAO Ying,CHEN Xiang,CHEN Di 2010, 44 (08):  1100-1102.  Abstract ( 3287 )   Save By improving the existing equipment of our laboratory, the process of inclined and rotating UV lithography in the fabrication of conical outofplane microneedles was researched and conical outofplane microneedles of PDMS were produced through pattern transfer between polymer materials by the SU8 photoresist mold. This method has the advantages of low cost and wide material applicability. The microneedle with the inclination of 67 °and the height of 353 microns was made by this method. Related Articles | Metrics

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Performance Evaluation of IEEE 802.15.4 MAC with Sleep Mechanism XIAO Zhuoling,HE Chen,JIANG Lingge 2010, 44 (08):  1103-1108.  Abstract ( 3442 )   Save An exactly slotbased and thus accurate model for IEEE 802.15.4 protocol with sleep mechanism in real time application was proposed. The model explicitly takes into account both the sleep mechanism and CSMA/CA mechanism of IEEE 802.15.4. By dividing the superframe into backoff slots and modeling the two mechanisms with a precision of slot, it analyzes the energy consumption, throughput, and service time delay of the protocol and discusses the impact of network traffic, duty cycle, especially sleep mechanism on protocol performance. The NS2 simulations show that the model can accurately predict the performance of IEEE 802.15.4 networks. At the same time, under the same packet arrival rate, a proper duty cycle could optimize both the energy consumption and network throughput. Related Articles | Metrics

Biomedical Engineering

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Development of Wireless Energy Supply Module for Wireless Capsule Endoscope XIN Wenhui,YAN Guozheng,WANG Wenxin 2010, 44 (08):  1109-1113.  Abstract ( 3236 )   Save To address the insufficiency of energy by battery for wireless capsule endoscope (WCE), a novel wireless energy supply module which can transmit energy to WCE based on inductive coupling was introduced. For the orientation indetermination of WCE in the human body and the miniature outline of WCE, an appropriate power transmitter and receiver were designed and tailored, and the effect of power transmission by this module was verified by experiments. The result shows that at least 150 mW powers can be transmitted to WCE when the inputting power is 18W and the outline of power receiver is 10 mm×11 mm, which fits the requirement of WCE. Based on this work, a WCE is made out and clear images of pig’s small bowel are gotten in the vitro experiments. Related Articles | Metrics

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Numerical Simulation of OptoThermal Response of LaserIrradiated Bovine Tissue for DynamicallyChanged Optical and Thermal Properties TONG Yaxing,HUANG Meizhen,DING Haifeng 2010, 44 (08):  1114-1119.  Abstract ( 3729 )   Save The effect of optical and thermal properties dynamicallychanged with temperature on the opticalthermal response of laserirradiated bovine tissue was studied and the finiteelement method was employed. The simulation result shows that ① the temperature increase will be overestimated when both optical parameters(μa and μs) and thermal parameters（c, k and ρ）are assumed to be constant; ② compared with thermal properties, dynamical optical properties will cause a greater degree of influence of bovine tissue temperature response; ③ during the irritation of laser, there will form an optical barrier near the surface of bovine tissue, which will affect the distribution of the photon within the bovine tissue and this result was proved by MonteCarlo method. Related Articles | Metrics

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Variances Handling for Clinical Pathway Based on Takagi-Sugeno FNNs with Random Cooperative Decomposing PSO Optimization DU Gang1,JIANG Zhibin1,DIAO Xiaodi2,YAO Yang3 2010, 44 (08):  1120-1124.  Abstract ( 4250 )   Save A variances handling method for clinical pathway was proposed, which is based on TakagiSugeno (TS) fuzzy neural networks (FNNs) with random cooperative decomposing particle swarm optimization (RCDPSO). During the process of cooperative coevolution with random execution sequence, a decomposing algorithm was adopted for the particles with the highest performance, and crossover and mutations were adopted for the particles with the worst performance. Therefore, it not only ensures the convergence rate, but also improves performance of the algorithm in global search. Moreover, the variation disturbing mechanism was introduced to strengthen the diversity of population and avoid plunging into local optimum. Finally, a case study on liver poisoning of osteosarcoma preoperative chemotherapy was used to validate the proposed method. The result demonstrates that TS FNNs based on the RCDPSO achieves superior performance in prediction and robustness to TS FNNs based on other algorithms, which makes variances handling of clinical pathway more effective. Related Articles | Metrics

Bilogical Science

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ThreeDimensional Modeling and Simulation of Periodontal Ligament Based on Hypoelasticity WEI Zhigang1，TANG Wencheng2，YAN Bin3，YANG Baokuan3 2010, 44 (08):  1125-1129.  Abstract ( 3685 )   Save The hypoelastic constitutive model of periodontal ligament was built and investigated. The validation of using hypoelastic model to describe the mechanical character of periodontal ligament was analyzed, a hypoelastic model of periodontal ligament based on uniaxial extension data was deduced and built, with a hypothesis of isotropy and small strain. A viscoelastic model based on hypoelastic model and its parameter was derived. A dental finite element model was built to conduct analysis, with the same boundary condition of experiment in literature. The analysis result conforms to the experimental result. It is concluded that the character of periodontal ligament can be represented well with an isotropic hyperelastic model，the constitutive model of periodontal ligament is only an equivalent model and should be built according to the boundary condition adopted in finite element analysis. Related Articles | Metrics

General Industrial Technology

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Modal and Deformation Analysis of Dualmotor Driving Turntable’s Middle Frame DONG Jinglong，TAO Jianfeng，LIU Chengliang 2010, 44 (08):  1130-1134.  Abstract ( 3715 )   Save In order to analyze the deformation of the dual motor driving elastic turntable’s middle frame, a finite element model was established for modal analysis by ANSYS. Based on the method of modal superposition by ADAMS flexible module, the deformations of turntable’s middle frame driven by synchronous and asynchronous torques were studied, and the cause of deformation was analyzed. The maximum deformation position of the turntable’s middle frame was calculated. The results of simulation indicate that the driving turntable’s middle frame by synchronous torque and keeping its angular acceleration reasonable can effectively restrain the deformation. This paper provides an effective method of simulation for the dualdrive elastic turntable’s middle frame deformation analysis, and the conclusions are helpful for the further research on the deformation feedback control. Related Articles | Metrics

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Study on Flow Regime Identification of Cryogenic VaporLiquid Two Phase Flows in Vertical Pipes LIU Jiejing，ZHANG Hua，WANG Jing 2010, 44 (08):  1135-1139.  Abstract ( 3547 )   Save Visualization experiments and the PSD of pressure signal were used to identify cryogenic vaporliquid two phase flows regime in vertical pipes. The flow regime got from highspeed camera and one inferred according to the PSD of pressure signal of different location were compared. It is found that PSD which is usually used to identify room temperature two phase regime can also be used to identify cryogenic two phase flow regime; even in different heat flux, it all works. Related Articles | Metrics

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Fast Calculation Model of Adiabatic Capillary Tube Flow ZHAI Qianjun,GU Bo 2010, 44 (08):  1140-1144.  Abstract ( 3863 )   Save For the impact of capillary import pressure, import status, and structural changes on capillary flow, this paper proposed a new fast calculation formula. The formula has the explicit form, in which does not exist iteration, and it guarantees highspeed and absolute stability of the flow calculation. When the back pressure is given, the export flow can be judged whether it is a critical flow. Software is used to check point from the ASHER Handbook nomogram and a verification is given. The result shows that the average relative deviation is 2.17%, the largest relative deviation is 13.42%, the result is ideal. At the same time, the influence of the capillary diameter, length, and import status on the capillary flow is analyzed. The model can be used in capillary flow calculation model directly. Related Articles | Metrics

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Modeling and Simulation on the Actuation Performance of Shape Memory Alloy/Si Composite Diaphragm SUN Shuangshuang,DONG Jing 2010, 44 (08):  1145-1149.  Abstract ( 3313 )   Save The mechanical model of shape memory alloy composite diaphragm based on Si substrate was established by combining static equilibrium equations, geometric equation and physical equations by the method of the mechanics of materials to consider the coupled action between the shape memory alloy and Si substrate under thermal loads. The material nonlinearity of the shape memory alloy film is also considered. The actuation performances of the SMA composite diaphragm were simulated and discussed for one whole thermal loading cycle, which verifies that large actuation forces and displacements can be produced in a narrow temperature range due to the phase transformations of shape memory alloys. Additionally, the maximum deflection of the composite diaphragm varying with the thickness ratios of the Si substrate to the shape memory alloy film was studied. It is found that the maximum deflection of the SMA composite diaphragm decreases with the increasing of the thickness ratios. And the mechanical model established in this paper can describe and predict the actuation performances of the SMA composite diaphragm much more accurately when the thickness ratio is larger than five. Related Articles | Metrics

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Random Energy Flow Analysis of ThreeDimensional Frame Structure YOU Jin,MENG Guang,LI Hongguang 2010, 44 (08):  1150-1154.  Abstract ( 3424 )   Save The formulations of random energy flow analysis (REFA) for beam structures were derived, which applies to the loading situation of random excitation. The theoretical relationship between REFA and statistical energy analysis (SEA) was investigated for beam structures, and it is found that the energy flow characteristic reflected by REFA for bending wave field is similar to that exhibited by two coupling oscillators in conventional SEA. REFA was applied to a 3D frame structure consisting of 3 identical beams, where the effects of concentrated random force being exerted at different positions on the same wave component were mainly investigated. The results show that the driving position of the force can significantly affect the global energy response and power flow in the structure, while has little effect on the total energies of wave fields directly subjected to excitations. SEA was utilized to perform vibration analysis for the structure as well. The solutions from SEA and REFA indicate that, only for the subsystems directly excited, total energy responses evaluated by the two methods are in good agreement. Related Articles | Metrics

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Modeling and Numerical Simulation of the Large Deformation Behavior for Thermoplastic Olefin MA Qiu1,YU Shuang2，SU Xuming3,YU Zhongqi1 2010, 44 (08):  1155-1158.  Abstract ( 3787 )   Save In order to study the deformation behavior of a thermoplastic olefin (TPO) during tensile loading, a constitutive model based on molecular chain evolution was developed and was implemented into a finite element method (FEM). Then the deformation behavior and microstructure were coupled. The model includes rate dependent initial uniform deformation, yielding, strain softening, and strain hardening. The FEM was used to simulate the deformation behavior of TPO during tensile test. The results show that the constitutive model results are very close to the experimental data. The simulation results give a clear description of stress distribution and evolution of necking during threedimensional deformation. The FEM results provide fruitful information for virtual design of TPO parts under development. Related Articles | Metrics

Communication and Transportation

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Modeling and Optimizing Quay Crane Scheduling Problem with Deck and Crane Constraints in the Mixed Loading and Discharging Operations LI Chen,LU Zhiqiang,CHEN Lu 2010, 44 (08):  1159-1164.  Abstract ( 4085 )   Save The quay crane scheduling problem studied in this paper is to determine an assignment and a handling sequence of bays for quay cranes, considering the interference between quay cranes and the deck constraints. A mixed integer programming is proposed and some properties of the problem are deduced. A genetic algorithm is designed to obtain the near optimal solutions. A lowerbound is given to evaluate the effectiveness of the proposed algorithm. Computational experiments are conducted and it is shown that the proposed algorithm is effective and efficient in solving the problem. Related Articles | Metrics

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Accurate Geometric Modeling for Cutting Pipes of Offshore Platform CHEN Liuyun,YIN Yuehong,XU Wenchao 2010, 44 (08):  1165-1170.  Abstract ( 3204 )   Save An improved cutting technics of steel pipes of offshore platform was researched based on the fact that domestic pipe cutting machines are generally equipped with cutting torches which rotate around twoaxis today. Instead of the traditional cutting technics which is obsolete and based on an approximate cutting method with cutting torches rotated around single axis several years ago, this new technics applies an accurate geometric modeling method which results in an accurate cutting technics instead of approximate technics obtained by traditional approximate modeling method. The software simulation shows that, compared with traditional approximate cutting technics, this accurate technics, implemented by a cutting torch which rotates around two axises, can effectively reduce the cutting length so as to improve the cutting speed and time efficiency. Besides, the surfaces match better while being welded together as the accurate cutting technics fully follows the geometric properties of surfaces. Related Articles | Metrics