bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Analysis of Noise Impact on Duffing Chaotic Detection System Using Lyapunov Characteristic Exponents
Authors: Hu Wen Jing , Liu Zhi Zhen , Li Zhi Hui
Published: October 2011

Performance of the Duffing oscillator to detect weak signals buried in heavy noise is analyzed quantitatively by LCEs. First in the case of noise, differential equations to compute LCE s are derived using RHR algorithm, so the quantitative criteria to identify system states are obtained. Then using LCEs, the threshold value of the forced periodic term is found accurately. Finally the system state and state change are analyzed using LCEs by keeping the threshold value and varying the noise intensity, and the minimum signal to noise ratio is determined. By contrast of phase trajectories and LCEs, it shows that phase trajectories disturbed by strong noise sometimes are ambiguous to our eyes, but through LCEs, the system state can be identified clearly and quantitatively especially in strong noise background. So the minimum signal to noise ratio can be obtained accurately.
Research on an Improved Control Strategy for Harmonics Restraint of DFIG System
Authors: Meng Yan Feng , Dong Zhi Ran , Hu Shu Ju , Xu Hong Hua
Published: October 2011

An improved control strategy for harmonics restraint of doubly fed wind power system is studied in this paper. Considered low order current harmonics (5th, 7th and so on) caused by the distortion or unbalanced grid voltage conditions and the variations of generator itself parameters, an improved control strategy is proposed. In this control strategy, a proportional integral (PI) regulator paralleled with a harmonic resonant (R) controller in the synchronous reference frame is proposed for restraining the stator current harmonics. The control strategy presented in this paper has not effect on the control of fundamental current, and need not the harmonic separation filter and the sequence decomposition in multi reference frames. To verify the effectiveness of this control strategy, simulation model of DFIG system is developed in Matlab/Simulink, and experiments are implemented on the doubly fed experiment platform. The results of both simulations and experiments show that the control strategy proposed in this paper could restrain harmonic currents effectively and it is easy to implement digital control.
Study on the Mechanism of Ultrasonic Vibration Aided Electrical Discharge Milling in Deionized Water
Authors: Chang Wei Jie , Zhang Jian Hua , Zhu Tao , Wang Tao , Shen Xue Hui
Published: October 2011

Ultrasonic vibration aided electrical discharge milling in deionized
water is proposed and its mechanism is investigated in this paper. The tool electrode is formed to be walled pipe, and high pressure deionized water is supplied through it. Two groups of orthogonal experiments were carried out respectively, one group with ultrasonic vibration on tool electrode and the other without. Research results show that ultrasonic vibration can improve the machining process and surface roughness.
The Dynamic Analysis and Optimization Technique of Non-Stationary Random Vibration
Authors: Qin Zhen , Xu Wen Tao
Published: October 2011

This paper introduces a new non-stationary random vibration technique for the analysis of time-dependent random vibration systems. It is based on the pseudo-excitation method (PEM) and precise integration method (PIM), which is extended herein and can improve significantly the analysis efficiency. Based on the random vibration equations with the right-hand side random replaced by a pseudo excitation, the first and second orders of sensitivity formulae are calculated conveniently by differentiating these equations. By use of sensitivity information, the optimization of complicated random vibration can be performed easily. Some numerical examples of vehicle-bridge time-dependent coupled system show the effectiveness and accuracy of present method.
Experimental Study on Continuous Preparation of Ultrafine Silicon Nitride Powders in Transport Bed
Authors: Yin Shao Wu , Wang Li , Tong Li Ge , Yang Fu Ming , Li Yan Hui
Published: October 2011

Ultrafine e grain amorphous silicon nitride (Si3N4) powders were produced via direct nitridation process of silicon powders in transport bed. The properties of the nitridation products, such as morphology, phase composition, chemical composition and structure, were examined using standard characterization techniques (SEM, XRD, FTIR, etc). The experimental results showed, in the case of silicon powders with particle size of 2.7μm, the conversion rate of silicon was 53.4% at reaction temperature of 1380°C and reaction time of 2.7minutes, and the products mainly comprised amorphous silicon nitride powders.
Design and Properties of Multifunctional Lubricant
Authors: Hu Kun Hong , Chen Gang , Cai Yong Kui , Zheng Jun Sheng , Xu An Bin
Published: October 2011

A MoS2/TiO2 nanocomposite was synthesized and characterized. Its lubricating properties and photocatalytic activity were also investigated, respectively. The as-prepared MoS2/TiO2 nanocomposite presented anti-friction properties better than those of the pure nanoMoS2. However, the difference in the anti-wear properties was not very notable between the pure nanoMoS2 and the MoS2/TiO2 nanocomposite. Moreover, the MoS2/TiO2 nanocomposite was also an excellent photocatalyst for the degradation of organic chemicals.
The Structures and High Temperature Properties of FeMnCrNiAl/Cr3C2 Composite Coatings by High Velocity Arc Spraying
Authors: Chao Yong Jun , Weng Jun Jie , Liu Shao Guang , Li Jian , Sang Jin Peng
Published: October 2011

The FeMnCrNi/Cr3C2 inter metallic composite coatings are prepared by high velocity arc spraying (HVAS) technology on 20G steel. The properties, such as the microstructure, micro hardness, binding strength, high temperature oxidation, thermal shock resistance, and erosion in high temperature, are studied based on methods such as analysis of optical microscope, micro hardness, field emission scanning electron microscope (FESEM), and spectrum analysis. The result shows that FeMnCrNiAl/Cr3 C2 coatings, compared with 20G steel substrate, present higher micro hardness, binding strength and more excellent high temperature properties, which will be improved if added with rare-earth Alloy.
Groundwater Numerical Simulation in Cool Water Well Coal Mine
Authors: Liu Yu Jie , Liu Guo Dong , He Yi , Nie Zhong Quan
Published: October 2011

Coal mining had destructed and polluted precious groundwater resources of Cool water Wells coal mine. To more accurately assess the groundwater resources and forecast coal mine groundwater systems status and change trend under state of development and utilization is the foundation work of mining area environment protection and treatment. The paper established the groundwater numerical simulation model in the study area using Visual MODFLOW software, calculated and evaluated the groundwater resources of study area by identification and examination.There are important practical significance to protection preciou water resource of mining area.
Bearing Performance Analysis Based on ANSYS of Continuous Deep Beams with Opening
Authors: Liu Jing Yu , Liu Hua Xin
Published: October 2011

The numerical simulation of reinforced concrete continuous deep beams with opening is analyzed by Finite Element Software ANSYS to establish reasonable mechanical model. The stress characteristics and deformation’s situation of the deep beams with opening are analyzed under concentrated load and different openings in different parts. The purpose is to supply some favorable suggestions in engineering application of reinforced concrete deep beam with openings.
Fraction of Multiphase Flow Measurement System Design and Application
Authors: Bing Xu , Ping Qian , Kai Zeng
Published: October 2011

This paper introduced the application of pattern recognition in the measuring phase fraction of gas-powder mixed flow. Flow-through measurement system based on virtual instrument techniques; include the techniques of electrical capacitance tomography and cross-correlation velocity measurement technology. The module structure of the system is present. According the principle of the phase fraction based on pattern recognition technology, the arithmetic with C++ program is described in the paper. The experiment process for this flow-through measurement system and experiment results are described in this article.
Discussions about the One Time Rotation of a Body of Revolution to the Designated Position
Authors: Dong Pei Bei , Li Shuo
Published: October 2011

In this article, the one time rotation of a body of revolution to the designated position under any conditions is studied, especially when the rotating front and rear of a body of revolution are on different planes, in which case, descriptive geometry graphic solution is employed to solve the rotation axis and rotation angle. Compared with other methods, this method is simpler and more visible. The solution of the problem will greatly contribute to the simplification of production processes, thus lowering product costs and improving economic benefits.
Mechanical Model’s of Conical Valve’s Spool-Seat Contact Pairs Based on the Hertz Theory
Authors: Jiang Hai Bing , Ruan Jian , Xu Hui Min , Wang Tao
Published: October 2011

Conical valve’s spool-seat contact pairs is consisted of two surfaces of different curvature radius, and form closed circular contact line. It can be considered as the model of elastic hemi-space contact by the Hertz Theory. The numerical simulation and experiment show: The model is suitable for the analysis of conical valve’s spool-seat contact pairs. The conical valve’ sealing performance is very credible and its performance is very good. Maximum stress is smaller than allowable stress of the seat’s material. The consistency of experiment and simulation proves the validity and practicability of the hemi-space contact model of the valve’s spool-seat contact pairs.
The Application of GPS in Glacier Flow Velocity: A Case Study of Qiyi Glacier
Authors: Liu Li , Jing Zhe Fan , Zhang Xiu Juan
Published: October 2011

Surface flow velocity is a key parameter of glacier kinetic theories study. With the help of GPS, glacier surface flow velocity research improved convenient and accurate. Therefore, this paper is committed to acquire the condition of surface flow velocity of Qiyi Glacier during 2009 to 2010 based on GPS data, optical remote sensing images and topographic maps. And it is concluded that during this time, the average surface flow velocity of Qiyi Glacier is decreasing while distributed relatively fast on central and slowly on both sides, and area retreated about 0.06km2 compared with that of 1965, whose value is consistent with motion mode of mountain glacier and the tendency of changes in Qiyi Glacier according to ELA data and Mass balance.
The Research of the Flotation Recovery Prediction Methods Based on Advanced LS-SVM
Authors: Zhang Yong , Zhu Jing , Liu Tan
Published: October 2011

Flotation recovery is an important index of flotation process, in order to change the existing detection methods of low accuracy , a soft measurement model of flotation recoveries is proposed based on improved weighted LS - SVM. According to the flotation foam characteristics and the corresponding relation of flotation recovery, the fuzzy C-means clustering method is used for flotation characteristics of data processing , the image characteristic values as prediction model input and using genetic algorithm to optimize the parameters of the model. The result show that the modified algorithm can overcome a prediction standard model LS - SVM algorithm parameter optimization shortage, and have better forecasting effect which provide effective protection for flotation process operation and flotation operation stable operation optimization .
A Stable Narrow Line-Width Dual-Wavelength Fiber Laser Based on Nonlinear Polarization Rotation with a High Finesse Ring Filter
Authors: Yang Xiu Feng , Peng Lei , Tong Zheng Rong , Cao Ye , Dong Feng Juan
Published: October 2011

A stable narrow line-width dual-wavelength fiber laser based on nonlinear polarization rotation with a high finesse ring filter is proposed and demonstrated. A polarization-dependent-isolator (PDI) and a section of polarization maintaining fiber (PMF) form an equivalent birefringent filter. Moreover, a ring filter can produce high finesse due to the weak gain generated by the EDF. As a result, two stable wavelengths are generated which both have about 18dB extinction ratio, 16dB side mode suppression ratio (SMSR) and 0.16nm 3dB line-width. Plus, less than 2 pm of the wavelengths shift and smaller than 0.4 dB of the optical power fluctuation when the system is operating in room environment for a period of 40 minutes indicate that the ultra narrow line-width fiber laser is very stable.
A Camera Calibration Method Based on Free Points
Authors: Zhang Jing Lei , Fan Kai Bo , Wang Yan Jiao
Published: October 2011

A new accurate calibrating technique for intrinsic parameters and extrinsic parameters of CCD camera is described. The camera model is derived by the pinhole projection theory. Then other parameters of the model are resolved under the radial alignment constraints and orthogonal constraints. In order to get a fine initial guess for the nonlinear searching solution, the least square method is introduced, and finally uses radial alignment constraint method to get the results. The experimental results show that the mean absolute differences in x direction and y direction are 0.0070 and 0.1430 separately while the standard deviation are 0.5006 and 1.2046 separately.
Research of Tower Crane Suspended Climb Supporting System
Authors: Li Bin , Li Lei , Bo Liu
Published: October 2011

Tower crane is one of the necessary tools in the construction of high-rise buildings.The municipal henglong square of shenyang city is to build as a landmark buildings of the city. In order to guarantee the normal operation and work of tower crane, the research of tower crane suspended climb supporting system is really essential. First of all, This article considers the building structure and construction of the safeguard, researches and designs tower crane suspended climb supporting system , then calculates and analyses the superiority and rationality of the structure through MATLAB and ANSYS. At last, it has proved the practicality of the tower crane suspended climb supporting system in this article.
Influence on Electric Field Distribution of GIS Basin Insulator for Insulated Material Epoxy Resin with Different Mean Molecular Weights
Authors: Gao You Hua , Liu Fei , Gao You Feng
Published: October 2011

The insulation material epoxy resin mean molecular weight to its solidification electrical performance influence is discussed. In view of the bisphenol A epoxy resin with different mean molecular weights, Finite Element Method (FEM) are introduced and electric field calculation equations are established to calculate the field distribution of basin insulator and its around region in GIS. Representative potential distribution curves are shown. The tangential and normal electric filed intensity maximum of basin insulator is calculated. The positions of electric field intensity maximum are also given.
Control System of PDP Lighting Inspection Machine
Authors: Liu Rui , Liu Gui Xi , Chang Peng Ju , He Wei Hua , Huang Zeng Jian
Published: October 2011

The test of panel’s display effect is a key step in the panel production. Lighting inspection machines test the electrical, optical and surface information of Plasma Display Panels (PDPs). This machine is based on a PLC control system and a color analysis system. The PLC system controls a visual positioning system and links to Manufacturing Execution System (MES) and a panel conveyor. This paper considers the structure design and action workflow of the lighting inspection machine. Multi-layer network is built to connect with the whole production system. Optional operation modes are designed in control program and Man-machine interface is introduced to facilitate the operation.
Data Acquisition for Output Signal of Linear CCD
Authors: Xu Guo Sheng
Published: October 2011

In order to improve the precision, speed, integration and reliability of the linear CCD system, A method of data acquisition for high resolution output signal of linear array CCD using FPGA is introduced. The CCD signal acquisition circuit with high speed and high sensitivity is designed based on the combination of FPGA with high-speed A/D conversion chipset to gather the signals of high-speed. The experimental results demonstrated that defects within 50μm~1000μm were inspected effectively by the CCD scanning defects inspection instrument, that this method has a repetition error no more than 2.24 pixels, with high precision and good anti-noise ability.
Geometric Features Sensitive Mesh Segmentation Orient to Patch-Based Fitting
Authors: Zhao Xiang Jun , Lu Mei , Gong Jian Hua
Published: October 2011

Segmenting meshes into natural regions is useful for patch-based mesh fitting. In this paper, we present a novel algorithm for segmenting meshes into characteristic patches and provide a corresponding geometric proxy for each patch. We extend the powerful optimization technique of variational shape approximation by allowing for several different primitives to represent the geometric proxy of a surface region. Our method has the particular advantage of robustness. As the principal curvatures of the surfaces become more equal, the returned results are become closer to the surfaces of geometry primitives, i.e. planes, cylinders, or cones, or rotating surface which are the most common patch types in the reverse engineering. The expected result that we recover surface structures more robustly and thus get better approximations, is validated and demonstrated on a number of examples.
Research on Anti-Collision Technology with Multiple Tags for RFID System
Authors: Hong Zhang , Zhang Xing Hui , Guo Jian Li
Published: October 2011

ALOHA algorithm can’t prevent collision much effectively, the process of anti-collision is longer while the amount of tags plunged collision is numerous, and sometimes the problem about estimating mistakenly arises. Binary search algorithm, which identification efficiency is higher, the problem about estimating mistakenly can’t arise, but its delay tima is more longer, security is short. The amelioration algorithm, return binary search algorithm can identify tag more effectively and rapidly, identifying time and the amount of tags is the relation of line form. The significance is very momentous that vast goods are identified, traced and managed by this amelioration algorithm.
Pulse Power Supply Control System
Authors: Zhang Xiang Jin , Shen Na
Published: October 2011

A novel pulse power supply charge and discharge automation control program is proposed. The program is based on optical encoder communication mode power supply switch trigger technology. According to the requirements of control system and through the analysis of high power charge and discharge characteristics of pulse power, the whole design for the control system (multiple channels) is completed.
Research for Vision-Based Mobile Robot Self-Localization Strategy
Authors: Li Guang Hui , Jiang Zhi Jian , Pan Bin
Published: October 2011

Mobile robots are a very dynamic part of the robotic domain, self-localization is one of the basic functions of them, in the complex environment, and whether to achieve precise localization is the key factor for mobile robot navigates accurately. In this paper, on the basis of the mobile robot can identify the set artificial landmark correctly through its vision sensors, then, based on the observe landmark and perspective localization method, the mobile robot’s position and moving direction can be calculated in the world coordinate system. Finally, a lot of experiments are carried out, the experimental results show that in the structural environment, this mobile robot can realize self-localization under this method perfectly, and the localization accuracy and sampling frequency meet the need of practical requirement.
Performance Parameter Estimation of the Parallel Hybrid Electric Vehicle
Authors: Zheng Yan Ping , Tian Tian , He Zhengang
Published: October 2011

Based on the theory of HEV (Hybrid Electric Vehicle) and the idea of reverse simulation, the simulation model of the parallel HEV is established in MATLAB and the estimation of the energy efficiency, the power performance and the fuel economy of HEV is achieved, which provides reference for the performance estimation of parallel HEV. At the same time the definition and the estimating method about HEV energy efficiency were mentioned in this paper and the energy efficiency can be achieved by the simulation model. The results of the simulation show that this estimating method has certain practicability and convenience.
Simulating Research of Integrated Control for Automobile Steering Stability
Authors: Shi Chuan Long , Liu Chuan Hui
Published: October 2011

In this paper, four-wheel steering and direct yaw-moment integrated controller is designed. To verify the effectiveness of the integrated controller, a nonlinear three-degree-of-freedom model is employed for computer simulation. Considering the nonlinear effects of tyre, Pacejka tyre model was adopted to set up the nonlinear vehicle dynamic model. The direct yaw-moment controller was designed based on optimal control theory. Simulation on the nonlinear vehicle with integrated controller in Matlab/Simulink software environment was described. The simulations suggest, compared with FWS and 4WS, the integrated controller can make the handling and stability performance on big lateral acceleration and slip angle improved, and make the driver drive the vehicle normally. The conclusion can be useful for the system design of vehicle stability control system.
Robot-Assisted Upper-Limb Fuzzy Adaptive Passive Movement Training and Clinical Experiment
Authors: Pan Li Zheng , Song Ai Guo , Xu Guo Zheng
Published: October 2011

In the effort to make robot-assisted upper limb passive movement training effective for neurologic injuries suffered from stroke and spinal cord injury (SCI), a new fuzzy adaptive closed-loop supervisory control method for passive joint movement training is proposed. Firstly, high-level supervisory controller for the desired passive range of motion (PROM) is designed based on the impaired limb’s joint motion recovery, and then low-level closed-loop position tracking controller is presented to drive the robot stably and smoothly to stretch the impaired limb to move along the predefined trajectory. The suggested strategy was applied to the four degrees of freedom (DOF) Whole Arm Manipulator (WAM) rehabilitation robot to evaluate its performance. Experimental results carried out on the 4-DOF WAM rehabilitation robot show the effectiveness and potentialities of the fuzzy adaptive passive movement control in clinical application.
3D Numerical Simulation of the Airflow in a Pneumatic Splicer
Authors: Xing Xiao , Ye Guo Ming
Published: October 2011

To investigate the effect of air flow in an pneumatic splicer on splicing performance, a computational fluid dynamics (CFD) model has been developed to simulate the air flow characteristics in an splicing chamber. Three-dimensional numerical simulation is conducted and standard K-ε turbulence model is used. Velocity distributions in the chamber are presented and analyzed. The computational results show that the velocities in the chamber are transonic. The air flows in the chamber are two swirling flows with opposite directions. This work also shows that CFD technique can provide a better understanding of the behavior of the high speed air flow in the air splicing chamber.
Preparation and Photocatalytic Activity of TiO2/Fe2O3 Nanocomposite
Authors: Hu Su Juan , Zhang Xuan Hui , He Ying , Hu Xian Chao , Cheng Lei , Li Guo Hua
Published: October 2011

TiO2/Fe2O3 nanocomposite was fabricated by a hydrolysis-precipitation approach, with TiCl4 as precursor and Fe2O3 as support. The crystal phase, diameter and morphology of the sample particle were characterized by X-ray diffraction, transmission electron microscope. The results show that the samples are composed of haematite and rutile. The morphology and diameter of rutile particle, coating effect and weight percentages of haematite and rutile are related to the preparing temperature and molar ratio of Fe/Ti. The photocatalytic activity of the prepared photocatalyst was estimated in an aqueous solution at ambient temperature of 303K. The results imply that the photocatalytic activity of the sample is higher than that of phase pure rutile, related to Fe/Ti molar ratio and its preparing temperature. These results can be attribute to the microsturcture of the sample. A synergistic effect exists between titania and haematite in the nanocomposite.
Design of a Time-Varying Continuous Control to Solve the Potential Field Local Minima Problem
Authors: Yang Jian , Dong Mi
Published: October 2011

The subject of this paper is the local minima problem (LMP) inherent in potential field methods (PFMs). Firstly, the underlying theoretical basis of LMP is formulated and its theoretical difficulty of control design is analyzed. It is shown that there does not exist a static state feedback control to solve LMP. Then a time-varying continuous control law is proposed to tackle this problem. In particular, challenges of finding continuous control solutions of LMP are discussed and explicit design strategies are then proposed. Moreover, systematic rigorous Lyapunov proof is given to show both global goal convergence provided that the goal is globally reachable and obstacle avoidance of the proposed controls. Simulation results are provided to illustrate the validity and effectiveness.
Synchronization Controlling for the Chu Chaotic System via Linear Feedback
Authors: Jian Ji Gui , Deng Xiao Lian , Shen Yan Jun
Published: October 2011

Based on inequality techniques and matrix theory, linear feedback control both with one input and one state or two states and with multi-inputs is proposed to realize the globally exponential synchronization of two Chu chaotic systems. Some new sufficient algebraic criteria for the globally exponential synchronization of two chaotic systems are obtained analytically. The controllers here designed have simple structure. Numerical simulations are presented to show the effectiveness of the proposed chaos synchronization scheme.
The Design of a Complex early Fire Monitoring Node
Authors: Liu Shi Xing , Deng Tian , Du Kan Kan
Published: October 2011

Companying with a fire, several feature parameters will be generated. In order to indicate a fire disaster effectively, a design that can detect three kinds of these feature parameters (temperature, CO gas and smoke) is introduced in this paper. The peripheral environment feature parameters will be converted into digital data by corresponding sensing modules included in the nodes. The data will be transmitted to the host computer based on TCP/IP and processed by Neural-Net Algorithms. Though the analyze of the data from the experiment, the nodes show a quick real time response, good operation stability and high speed data transmission. They are very suitable for early fire monitoring in modern buildings to protect human life and properties.
Column Strength and Stability Analysis of Column Pipe Automatic Transferring System
Authors: Sha Yong Bai , Zhu Ji Liang , Zhao Xiao Ying , Wan Xiao Peng
Published: October 2011

Pipe automatic operating system uses mechanical,hydraulic and control technology, replace manual operation by using mechanical equipment,it is an effective way to make drilling safe,healthy and efficient.In the paper,the general mechanical structure,and working principle of the column pipe automatic transferring system of land rig are introduced.The strength and stability analysis of column are presented.provided a way of strength and stability analysis.
Static Analysis and Parameter Optimization of the Grab Bucket
Authors: Wang Xian Long , Liang Qing Hua , Guo Wei Zhong
Published: October 2011

This paper aims to provide an optimum design for the grab bucket on the port, analyze the parameters related to its grabbing function from static aspect. Taking the minimum grabbing moment as static elevation indicators, a nonlinear multi-variable optimization model was established taking the grabbing torque as the objective function. A function atlas was drawn on this purpose. The Matlab GA toolbox has been used in optimal design of the key parameters of grab bucket which used to be designed according to experiences, to improve the grab torque which leads to better performance and the higher efficiency of the grab bucket .In the end, an case was studied to demonstrate its effectiveness.
Simulation System for General Aviation Primary Flight Display Based on GL Studio
Authors: Zhang Xue Jun , Meng Fan Wen , Han Dong
Published: October 2011

A simulation system consisting of display module, control module and process module for general aviation (GA) primary flight display (PFD) was designed in this paper. Realized with GL Studio, the system can receive, process and display the flight information as while as response to the operator’s control in real time. The testing results indicate that the system has good interactivity, stability and real time property which meet the requirements of simulation. The system can be widely used in GA avionics design and simulation training.
Decision of the Weight of Expert in the Analysis of Creditability of Simulation Model
Authors: Liu Sheng , Li Li Hong , Cheng Yin Zhong
Published: October 2011

In order to better determine experts’ weights in analyzing the credibility of simulation model, a new method is proposed in this paper. The deviation between experts is combined with Dempster-Shafer theory to construct the objective function of expert’s weights. And through analyzing creditability of simulation model of the ship electric propulsion system, the proposed method is proved to be feasible.
The High Frequency Pulse Effect and Verification in the Welding Process for High-Strength Aluminum Alloy
Authors: Yan Si Bo , Song Yong Lun , Zhang Jun , Bai Li Lai
Published: October 2011

The plate butt welding tests have been carried out to the 2219 high-strength aluminum alloy material by utilizing the self-development compound high frequency pulse TIG power source, whose results show that the mechanical properties of the welding seam may be effectively enhanced by adding the high frequency pulse energy. Therefore, a acoustic emission sensing system was established to acquire the transmission effect of the high frequency pulse arc energy during the welding process; moreover, the influence on the welding seam microstructures by the compound high frequency pulse energy has been studied. The results show the following effects: the porosity number at the both sides of the welding seam fusion line may be decreased significantly by adding the high frequency pulse energy; The analysis to the high frequency pulse action mechanism has been carried out according to the above conclusions to provide the technology theory base for improving and enhancing the aluminum alloy welding joint performances.
Implementation and Experiment Verification of a Metro Power Traction Simulator System
Authors: Dong Xing Jian , Zhuang Sheng Xian , Liu Ai Ping
Published: October 2011

A metro power traction simulator system is designed and implemented. Designation method of the flywheels which simulate the metro vehicle moment inertia is given. A train runtime diagnosis system is completed by adopting MVB protocol. The dynamic simulation of metro power traction system is realized under the control of train runtime diagnosis system. The feasibility and utility are proved by the experiment results.
Design of PMSM Servo Control System Based on TMS320F2812DSP
Authors: Lu Yang , Gao Zhi Feng
Published: October 2011

This paper presents a design of PMSM (Permanent Magnet Synchronous Motor) double-loop servo system based on TMS2812DSP hardware platform, programmed by C language in Q format, and using the theory of vector control along with the technique of SVPWM ( Space Vector Pulse-width Modulation). This system can get widely used in the area of motor digital control system, automatic production line, etc, which demands highly precise servo control.
Analysis and Optimization of Flexible Supported Drive Train in a Wind Turbine
Authors: Zheng Li Ming , Li Hui Xin , Chen Yan
Published: October 2011

Based on conventional drive train model of wind turbines, a planetary gearbox with flexible supporting between gearbox case and nacelle base is considered, and the coupled dynamic model of the drive train system is derived. The gearbox inner vibration performances are evaluated under different flexible parameters by means of dynamic simulation. It is shown that natural frequencies of each shaft are drifting while damping and elastic coefficients changing. Analysis also reveals that the flexible supporting mitigates torsion vibrations of each shaft. To minimizing torsion vibrations, a new searching approach is used to find out optimal parameters of the flexible supporting. Simulation results show that dynamic torque loads of the drive train are reduced, which is useful to wind turbine structure design.
Adaptive Image Denoising Based on Sparse Decomposition
Authors: Jiang Yu Ting , Yin Zhong Ke
Published: October 2011

Different behaviors of image information and noise in sparse decomposition were studied to identify the differences between image information and noise. According to the different coherences between image (or residual image), noise and over-complete dictionary, image information and noise are distinguished. One image adaptive filtering is realized by taking coherent ratio threshold as the constraints of extracting available information.
Reactive Power Compensation of Distribution Network Based on Bacterial Colony Chemotaxis Algorithm
Authors: Wang Hong Liang , Li Lin Chuan
Published: October 2011

Reactive power compensation of distribution network is an important method to improve power quality and voltage stability, while reducing the power loss of the distribution network. In this paper the objective function is built to minimize all the costs which include power loss costs and investment of the dynamic reactive power compensation device divided into each year. The actual operation of the distribution network is simulated considering light, normal and heavy load operation conditions. Bacterial colony chemotaxis (BCC) algorithm is used to determine which nodes to install the compensation devices. The calculation of reactive power compensation is done with the back/forward sweep algorithm adapting to the radial distribution system. In order to compensate three different load conditions separately, the fixed part and the switching part of the dynamic reactive power compensation device are used. This method applies to 28-node system, the result demonstrates that the method is feasible and effective.
Design and Implementation of the Embedded Web Control System Based on ARM and Linux
Authors: Wang Yun Liang , Chen Bo Wei
Published: October 2011

With the rapid development of networks and communications technology, the modern remote control technique has widely been used in many fields. By the Web technology, the local equipments can be connected with outside and enable monitoring the equipments in remote clients' space. At present many products adopt Embedded Chip to which an operating system is ported as a Web Server. This product has several advantages such as low power consumption, low cost, reduced size and better performance. This paper introduces a solution for embedded system access to Internet, through which we can remote access, monitor, and maintain conveniently. The solution which is based on Web and embedded technology adopts the way of human computer interface interaction to realize remote control to the equipment. The realization of this method for users provides a convenient, flexible and effective control method.
Augmented Dickey-Fuller Test and the Lag Length Selection Problem
Authors: Deng Lu
Published: October 2011

Many studies indicated that ADF test is very sensitive to different leg length selection models. Based on Hall, and Ng, Perron’s works, this article simulates a more general ARIMA(0,1,q) process and compares the influence of different selection methods to the size and power of the ADF test. Finally, it is proved that the Modified Information Criteria always shows a more proper size and the General to Special Criteria has more robust ADF test properties.
Design and Simulation of a Broad Band Retrodirective Array Element
Authors: Hu Feng Ge , Zhang Jian Hua , Fang Li Ye
Published: October 2011

In this paper, a novel dual-polarized antenna fed by microstrip line for retrodirective array is presented. The star-shaped patch is used to reduce the mutual coupling among array elements; also bandwidth can be enhanced by choosing stacked patch. The simulated results indicate that the impedance bandwidth (VSWR<2) achieve 17%, the antenna gain is higher than 8dB, the port-to-port isolation and polarization isolation maintain at less than-20dB. A 1-D retrodirective array is designed based on this novel element, the array displays better retrodirectivity. It is validated that the dual-polarized microstrip antenna can be widely used in retrodirective array.
Fuzzy Control Strategy and Simulation for Dual Electric Tracked Vehicle Motion Control
Authors: Chen Ze Yu , Zhao Guang Yao
Published: October 2011

Based on tracked vehicle dynamics analysis, a fuzzy control strategy is proposed in this paper for the dual electric tracked vehicle motion control. The inputs of fuzzy system are driver acceleration, braking and steering signals besides vehicle velocity feedback signal, while outputs are dual motors’ torque commands and mechanical braker’s target force. Control strategy contains two fuzzy logics, one is for steering and straight-line running control, the other is for braking control section. Simulation results show that the fuzzy control strategy presented here is correct and effective for electric tracked vehicle motion control.
Creating Logic to Solve the Problems in Modeling for Simulations
Authors: Mi Liang Chuan , Wang Shi Gang , When Quan Yi , Xu Chang Shun
Published: October 2011

For a very long period of time, the concepts of logic or formula logic and engineering or recognition are separated strictly. It is studied in the paper about the common sense of them, and which are combined together in the course of human being knowledge learning. According to some typical examples, the conclusion was drawn and a new viewpoint was got, which would be the most artistic works in the world. The new form of logic invented in the paper, perhaps would be a general principle for modelling in the system simulation.
Exact Mathematical Model and its Numerical Solution of a Two-Layer Beam Subjected to Non-Uniform Temperature Rise
Authors: Chang Xue Ping , Liu Jun , Ren Ji Hong
Published: October 2011

Based on accurately considering the axial extension, geometrically nonlinear governing equations for a two-layer beam subjected to thermal load were formulated. By using a shooting method, the strongly nonlinear ordinary differential equations with two-point boundary conditions were solved and numerical solution for thermal post-buckling and bending deformation of a two-layer beam with pinned-pinned ends and subjected to transversely non-uniform temperature rising were obtained. As an example, equilibrium paths and configuration for a beam laminated by brass and steel are presented and characteristic curves of the nonlinear deformation changing with the thermal load were plotted. Effects of the geometric and material parameters on the deformation of the beam were discussed and analyzed in detail. The theoretical analysis and numerical results show that the bending deformation and the stretching-bending coupling terms of beam subjected to uniform or non-uniform temperature rising can be produced because of the non-homogenous distribution of the material properties. The bending deformation resulted from transversely temperature rise is primary deformation when values of average temperature rise parameter is under critical temperature, however, the curves become the thermal post-buckling equilibrium paths with the increment of average temperature rise when values of average temperature rise parameter exceed critical temperature.
A Study on the Harmonic Wave of SPWM Voltage Source Inverter
Authors: Xiao Wei Chu , Li Jia Sheng , Jiang Li Jun
Published: October 2011

A mathematical model for the output waveform of SPWM VSI (voltage source inverter) is created specific to the harmonic problem of SPWM voltage source inverter. Through theoretical analysis and calculation, we can get the distribution regularity of the output harmonic wave in the process of frequency conversion and voltage transformation. Utilizing the matlab to verify the simulation, we can get such results like “frequency conversion will lead to the shift of the harmonic wave’s distribution center”, “voltage transformation will cause the valuable change of the harmonic wave and the valuable change direction of harmonic wave is opposite to that of the fundamental wave”. All of these will have significant guide meaning to the application of SPWM.
Structure and Magneto-Resistance in Nanostructured Sr2Fe1-xCrxMoO6 (0≤x≤0.3) Double Perovskite Componds
Authors: Li Xiang Hu , Li Dan
Published: October 2011

The compounds of Fe substitution of Cr in nanotructured Sr2Fe1-xCrxMoO6(0≤x≤0.3) double perovskite have been prepared by sol-gel method. The x-ray diffraction patterns of the samples show that the samples are in nanometer range. And the average grain size D for these samples is 39.7, 37.1, 33.4, 31.9, and 31.2nm, respectively, decreases with the increasing of Cr ion. The saturation magnetization and the magnetoresistance of the samples decrease with the increasing of Cr for the disorder defects which increase for the close ionic radii of Mo and Cr.
Influence of Tungsten Doping in La2Mo2O9 Oxide-Ion Conductors by Dielectric Relaxation Measurements
Authors: Li Dan , Li Xiang Hu
Published: October 2011

The effects of tungsten doping in La2Mo2–yWyO9 (y =0, 0.25, 0.5, 1.0, 1.4) samples were studied using dielectric relaxation measurements. The results indicate that the solubility of W6+ in La2Mo2O9 sample is about 25mol%, W6+ can suppress the α/β phase transition in the La2Mo2O9. Additional to the low-temperature relaxation peak Pd associated with oxygen ion diffusion, a new dielectric loss peak Ph associated with a phase transition from the static disordered state to the dynamic disordered state of oxygen ion distribution was observed around 740 K. The conductivity of La2Mo1.9W0.1O9 sample is higher than that of the pure La2Mo2O9, and then decrease with the increasing of the tungsten doping in La2Mo2–yWyO9 (y = 0.5, 1.0) samples in the whole measurement temperature.
Micro-Simulation of Concrete Based on the Zero-Thickness Interface Element
Authors: Wu Sheng Xing , Wang Pan Xiu , Zhao Hai Tao , Huang Dong Hui
Published: October 2011

Intravascular Ultrasound (IVUS) is one of interventional imaging modalities widely used in clinical diagnosis of vascular diseases, especially coronary artery diseases. Segmentation of IVUS images to extract vessel wall boundaries is of importance for quantitative analysis and 3D vessel reconstruction. A 3D parallel method for segmenting IVUS image sequence is proposed in this paper. Firstly, original images are preprocessed to reduce possible noises and eliminate ring-down artifacts. Then, several longitudinal cuts are obtained and intima-lumen and media-adventitia boundaries are detected. Once these boundaries are mapped onto each cross-sectional slice, initial plan of vessel wall boundaries in each frame is obtained. Finally, these initial contours evolve continuously until stop at target contours. Consequently, segmentation of each IVUS tomographic frame isimplemented simultaneously and the efficiency is greatly raised compared with 2D sequential approaches.
High Efficiency Laser Diode Power Supply
Authors: Li Xing Guang , Li Gui Ying , Yue Yu Bo
Published: October 2011

A continuous light-emitting laser diode power supply has been present,in this paper. The power supply is up to 50 W and the current is continuous adjustable below 5A . The supply is easy controlled, miniaturization, high efficiency, non-impact and slow-start to meet the characteristics of laser diode. The efficiency of the supply is better then 93% by application test.
Numerical Simulation of Traffic Flow in the Tollgate Area with Variable Speed Limits
Authors: Zhu Wen Xing , Jia Zhi Ping
Published: October 2011

We investigate behaviors of vehicles passing a controlled area with variable speed limits (VSL) before a tollgate. The traffic flow mathematical model is formulated based on optimal velocity model. The typical sketch of tollgate area is plotted and variable speed limit signs are set in the area to control the traffic flow speed for fear of accident and congestion. Simulations are carried out to examine the influence on traffic flow passing the controlled area with different number of the speed limit signs under open boundary condition. The simulations results show that more speed limit signs may reduce the risk of rear-end collision and the occurrence of the congestion in the tollgate area.
Implementation of a New Travel Time Estimation Method for Demand Forecasting Models
Authors: Lu Chen Xi , Zhao Fang , Hadi Mohammed , Yang Ren Fa
Published: October 2011

This paper discusses the implementation of a new travel time estimation method in a regional demand forecasting model. The developed model considers implicitly the influence of signal timing as a function of main street and cross street traffic demands, although signal timing setting is not required as input. The application presented in this paper demonstrates that the developed model is applicable to a large network without the burden of signal timing input requirement. The results indicate that the application of the model can improve the performance of traffic assignment as part of the demand forecasting process. The model is promising to support dynamic traffic assignment (DTA) model applications in the future.
Design of Electromagnetic Smart Car System
Authors: Ye Meng Jun , Hu Chang Hui
Published: October 2011

The document introduces the self-tracing smart car system based on Fressscale MC9S12XS128 as the core control unit. Focus on the design of electromagnetic sensor unit, describe in detail differential electromagnetic sensor unit and position electromagnetic sensor unit, and then describe the speed adjusting system. Test shows that smart car based on position sensor unit have good forward-looking, real-time and accurate response.
Solitary Solution of Nonlinear Equation by Homotopy Analysis Method
Authors: Chen Xiu Rong , Cui Wen Shan
Published: October 2011

In this paper, we apply homotopy analysis method to solve nonlinear equation and successfully obtain the bell-shaped solitary solution to the nonlinear equation. Comparison between our solution and the exact solution shows that homotopy analysis method is effective and valid for nonlinear problems.
Optimal Control Design for Nonlinear Systems with Disturbances
Authors: Zhan De Zhi
Published: October 2011

This paper considers the optimal control design problem for nonlinear systems with composite disturbances. First, the original system is transformed into an augmented system without disturbances. Then with respect to the quadratic performance indexes of infinite horizon, we design an optimal controller for the augmented plant without disturbances. Thus the disturbances can unfold of the signal through the Taylor series for the form of polynomial function of time, and obtain optimal controller design approach to eliminate the general disturbance. Finally, a practical example is given to illustrate the effectiveness of the theory.