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April 30,2017
Volume 10,Issue 8
Pages -
Subject Area:Enterprise Management,Air Transport,Electrical Engineering,Electric Power System and Automation,Engineering Thermophysics

Title: Research on evaluation method of port competitiveness based on combination weights and TOPSIS method

Authors: PAN Kailing, YI Changwei
PP: 925-932
Abstract: In this paper, we build the evaluation index system of port competitiveness, which is the integration of static and dynamic indicators. Then we use the linear weighted method to determine the combination weights of the objective and subjective weighting methed, and the weighted TOPSIS method of the improved gray correlation analysis is used to evaluate the competitiveness of the port. In the end, we use the evaluation of ports competitiveness in the area around the Bohai sea as an example to prove that the method is effective and reasonable.
Keywords: management engineering; combination weighting method; analytic hierachy process; entropy value method; weighted TOPSIS method

Title: Research on the relationship between executives leaving and market value of GEM companies

Authors: LIU Xinmin, DU Suzhen, WANG Lei
PP: 912-924
Abstract: This research regards the GEM listed companies in 2009 to 2012 as samples, through an empirical analysis by Stata 14.0 of influence of executives leaving on the market value of firms, we find that the impacts of executives leaving on the market value are different in the overall market model and market adjustment model. And then we test the founding executives and non founding executives respectively. The result shows that the founding executives leaving has a significantly negative effect on the market value, while the non founding executives leaving has a significantly positive effect under the market model. Research conclusion provides a reasonable explanation on the current GEM executives’ frequent behavior of resign in order to cash their equity, meanwhile serves as a reference for the stable development of the growth enterprise market.
Keywords: business management; GEM companies; executives leaving; market value

Title: Analysis and research on route network optimization problem based on minimum cost flow

Authors: SONG Weiwei, JIA Lijuan
PP: 905-911
Abstract: In this paper, the optimization of airline network in the northeast region of China is taken as an example to construct a mixed integer linear programming model for the rich tourism resources, the numerous regional airports in the northeast region, reducing the cost and improving the convenience of passenger travelling and to realize the minimum operation cost in the whole route network. The improved tabu search algorithm and the shortest path algorithm are used to solve the model, and the layout scheme of the northeast routes is obtained and the feasibility of the scheme is verified. The example shows that the optimization of the existing route network in this region is the objective of optimizing the total route cost of the whole route network in Northeast China, and it is of practical significance to get the route network layout optimization scheme in Northeast China.
Keywords: air transport; route network; minimum cost flow; optimization

Title: Optimal model and algorithm for operation plan electric multiple units under stagger of overhaul peak

Authors: WANG Zhongkai
PP: 897-904
Abstract: This paper analyzed the relationship between the overhaul repair and the daily operation of electric multiple units, discussed the optimization strategy of operation plan combined with overhaul conditions. An integer optimal model was built to stagger the overhaul peak of electric multiple units, with the situation of overhaul, repair regulation of level one and two, and train diagram as the constraints. Particle swarm optimization was applied to find better solutions. As a result, adjusting operation schemes contributes to avoiding stagger of overhaul peak and provides a decision support for the production of electric multiple units.
Keywords: railway transport; operation plan optimization of electric multiple units; stagger of overhaul peak; particle swarm optimization

Title: Acceleration characteristic calculation of series hybrid electric vehicle

Authors: PENG Dengzhi, JING Dayong, ZHOU Zhenhua, WU Weixing
PP: 892-896
Abstract: Based on the calculation method of the traditional vehicle accelerating time and taking the characteristic of series hybrid electric vehicle into consideration, a new method is given to calculate the needed power of series hybrid vehicel when accelerated to a certain speed. The result of this new method is compared to the results of fitting method and vehicle field test. According to the comparison, the method provided in this paper can offer a better reference to evaluate the acceleration characteristic of series hybrid electric vehicle.
Keywords: vehicle engineering; acceleration time; acceleration characteristic; series hybrid electric vehicle

Title: Research on modeling and simulation of power electronic circuits based on FPGA

Authors: AN Jinlong, YANG Yinghua, XIN Bin, SHI Wen
PP: 885-891
Abstract: Aiming at the problems of rigid convergence in two-value resistance modeling and the increase of switching frequencies, the two-value LC method which describes the switching characteristics of switching devices will deviate from the actual characteristics of the switch, so that the simulation accuracy is reduced. In this paper, a switching modeling method, which is suitable for high frequency characteristics, is presented. Taking the Buck circuit as an example, the working principle is analyzed and the circuit model of the switch function based on field-programmable gate array (FPGA) is established. And compared with the simulation results in Plecs environment, the results show that the average relative error of the two results is only about 0.005%, thus verifying the validity and accuracy of the model and providing a modeling foundation for the simulation of high frequency power electronic circuits based on FPGA.
Keywords: electrical engineering; high frequency; field-programmable gate array; switching function; simulation verification

Title: Dynamic reactive power optimization considering the analytical impedance ratio in distribution network with wind power

Authors: LI Zhimin, GAO Weifeng
PP: 875-884
Abstract: In this paper, a dynamic reactive power optimization method considering the analytical impedance ratio is used to optimize the distribution network with wind power, which is based on the minimum network loss and the best voltage stability. This paper firstly introduces the derivation process of the analytical impedance ratio based on Thevenin equivalent. Then a new approach to load curve in segments based on Haar wavelet transform method is proposed, and at last, optimizes the loaded regulable transfer discontinuous wiper and the compensation capacitance switching. Taking the improved IEEE33-bus distribution system as example, the results reduce the movement of voltage control equipment and improve voltage stability of power system in the period of most time and the network loss increment is well controlled at the same time, which proves to be having certain applicable value.
Keywords: power system and its automation; dynamic reactive power optimization; analytical impedance ratio; voltage stability

Title: Simulation of asynchronous motor considering iron loss and inverter loss

Authors: SONG Guiying, WANG Lei, LI Xue
PP: 868-874
Abstract: In order to improve the efficiency of the motor control system, we deduce the mathematical model of three phases induction motor with iron loss in two-phase synchronous rotation frame based on rotor flux oriented control and inverter-loss mathematic model based on the directed current bus voltage and current to reduce the values of these two kinds of losses in the system. Then we establish the simulation model of the phase asynchronous motor with iron loss and inverter loss by PLECS simulation software, and we compare the model without these loss model. The comparison demonstrates that the model with iron loss and inverter loss is more close to actual asynchronous motor.
Keywords: power electronics and power transmission; motor iron loss; inverter loss; PLECS simulation

Title: Design of ejector cooling system and numerical simulation of internal flow field

Authors: WANG Sidong, WANG Yichun
PP: 859-867
Abstract: In this paper, a cooling system which uses the vehicle\'s exhaust gas energy was studied. A design method for the ejector was proposed. The design process for the vehicle cooling system was put forward. According to the theory of aerodynamics and heat transfer, the formula for the minimum ejector coefficient which was used to evaluate the ejector\'s performance was derived. Taking a certain type of armored vehicle as an example, we determined the minimum ejector coefficient the cooling system required through theoretical calculation, studied the impact of ejector\'s structure on the ejector coefficient, and find the most suitable ejector for the heavy-duty vehicle under the condition that meets the minimum ejector coefficient and the limited power cabin.
Keywords: engineering thermophysics; cooling system; numerical simulation; exhaust gas ejector; ejector coefficient

Title: Experimental investigation of nanoscratching of monocrystalline silicon

Authors: ZHANG Junjie, JIANG Yuqi, WANG Zhanfeng, YAN Yongda, SUN Tao
PP: 852-858
Abstract: In the present work, nanoindentation and nanoscratching of monocrystalline silicon with three different crystallographic orientations [(100), (110), (111)] are performed by using the MTS Indenter XP and a conical-shaped probe. The correlation between microscopic deformation of silicon and mechanical response is studied. The YOUNG\'s modulus of silicon is derived by fitting the load-displacement curve by using the Hertzian elastic theory. Meanwhile, molecular dynamics simulations of nanoscratching are performed, and the comparison between molecular dynamics data and experimental results in terms of values of YOUNG\'s modulus and profile of friction coefficient-displacement curve are performed. The results show that the nanoscratching-induced structural phase change of silicon leads to rapid evolution of mechanical response. Particularly, in the scratching stage, the competition between phase transformation and dislocation slip leads to strong characteristics of fluctuation of friction coefficient-displacement curve. It is found that the value of YOUNG\'s modulus and profile of friction coefficient-displacement curve obtained from molecular dynamics simulations are consistent with that from experiments.
Keywords: mechanical manufacturing automation; monocrystalline silicon; nanoscratching; crystallographic orientation; comparison between experiment and simulation

Title: Design of data network management system for mobile robot

Authors: XU He, ZHU Le, WANG Peiyuan, LI Chang, HU Mingyu, ZHAO Wanda
PP: 845-851
Abstract: The aim of this paper is to evaluate the movement and work efficiency of the mobile robot with the research of its data management. The data management system based on network was proposed, which was used to manage the data of the robot. The development of the mobile robot data management system includes system function design and Web interface design. The mobile robot with reconfigurable and adaptive capacity was studied. According to the sensors equipped in the mobile robot, the system function modules were completed, and the corresponding database was designed for data storage. With the real-time data storage and off-line data upload of the mobile robot in rugged terrain environment, the sample data for further research was provided.
Keywords: mechanical manufacturing automation; mobile robot; date management; database

Title: Research and design of real-time virtual monitoring system for manufacture process in workshop

Authors: LIANG Xingming, DONG Bolin, HE Qichang, TANG Huohong
PP: 838-844
Abstract: Aiming at the shortage of manufacturing excution system (MES) on the real-time monitoring of status in factory production and 3D human-computer interaction, we developed the virtual monitoring system for manufacture process in workshop based on the integration of Unity3D and HTML technology. This system mainly consists of three parts: 1) Scene display of the workshop. It’s based on B/S structure. With the design of the corresponding Web pages for displaying, and through the software of Unity, the system has achieved the effect of virtual reality. We also made many rules inside scenes to show data clearly. 2) Data acquisition. The TCP/IP protocol is used for data exchange between computerized numerical control (CNC) equipment and server, and the real-time status of all kinds of CNC machine tools is collected and stored in the Oracle database. 3) Information interaction between 3D plug-in and Web pages. The example shows that the system has the functions of real-time monitoring, 3D roaming, fault alarm, historical data inquiry and so on, which meets the factory’s requirements to monitor workshops in 3D technology.
Keywords: mechanical manufacturing automation; monitoring system for manufacture process; virtual reality simulation technology; human-computer interaction; B/S structure

Title: Gear enveloping experiment based on virtual gear enveloping instrument

Authors: CHANG Zongyu, ZHANG Yang, ZHENG Zhongqiang, SUN Jun
PP: 830-837
Abstract: In order to improve current mechanical gear enveloping instrument, a virtual gear instrument was developed, gear cutting and engagement principle teaching experiments were carried out. This instrument is based on the principle of gear enveloping motion, the generation of rack shape, translation of rack and caculation of rotational transition matrix were realized using Matlab. The GUI interface presented the shape of gear, human-computer interaction and the function of graphics and animation respectively. The virtual gear enveloping experiment has the advantages of accuracy, directly-displayed, which help to have a deep understanding of the principle of gear enveloping and promote the launch of virtual experiments and network experiments.
Keywords: theory of machines and mechanisms; gear enveloping; engagement principle; Matlab; GUI interface

Title: Fault analysis of motorized spindle of CNC machine tools based on Bayesian network

Authors: WANG Zexing, LI Debao, HE Qichang, TANG Huohong
PP: 823-829
Abstract: The failure analysis of computer numerical control (CNC) machine tools is of great significance to improve the reliability of CNC machine tools. Combined with fault tree analysis (FTA) and Bayesian network, this paper aims at the fault analysis of motorized spindle of CNC machine tools. First of all, we analyzed the structure of motorized spindle, then established its own fault tree. Secondly, we transformed the fault tree into a Bayesian network, and modifed the numbers of nodes’ statuses in the network to make up the deficiency of the fault tree as well. Finally, we built the Bayesian network model based on the Bayesian network toolbox of Matlab as well as combing with the historical data and verified the effectiveness of the model by experiments.
Keywords: machine design; motorized spindle; fault tree analysis; Bayesian network; Bayesian network toolbox

Title: Influence of stiffness index on gear vibration based on virtual prototype

Authors: WU Hao, LI Zhengminqing
PP: 818-822
Abstract: In the mechanical driving field, dynamic response of gear transmission system is an important issue. Based on 3D mechanical design software and virtual prototype, the dynamic model of spur gear transmission system was established, and we studied the effects of the stiffness index on the vibration characteristics. The simulation results show that the gear vibration decreases with the stiffness index increasing, which provides a feasible method for reducing gear vibration.
Keywords: machine design; spur gear; virtual prototype; stiffness index; vibration characteristics

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