bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of Strength of the Seats and Head Restraints Testing System
Authors: Yang Yi , Huang Hu , Wang Ji Chang
Published: February 2011

designed a equipment for testing the strength of seats and head restraints, the equipment can testing the seats and head restraints with the standard of GB 11550-1995 5.2. The equipment was composed of one upper cylinder elevating system, a beam elevating system, two load cylinders and a hydraulic station. In addition to designed the principle of the hydraulic system.
Design Optimization of a Hydraulic Caterpillar Vehicle Frame
Authors: Qin Yong Fa , Chen Si Dong , Dong A Zhong
Published: February 2011

Expounds characteristics of the frame structure and function of a hydraulic walk caterpillar vehicles. A frame structure is designed to suit for a caterpillar running system with hydraulic pump- motor circuit. While to design such a frame, there must be a tradeoff between mechanical property and its mass. Based on establishing the geometric model of the frame, the finite element method is used to analyse the distribution of stress and strain of the frame in its working condition. Furthermore, aim to reduce the mass of the frame, a programme is designed and applied to find the best tradeoff point between requirment and mass. The programme is developed using APDL(ANSYS Parametric Design Language). The simulated example showed that the propose method in this paper can be applied to optimize the frame of caterpillar vehicles.
Dissipative Control for Nonlinear Neutral Delay Systems
Authors: Liu Long , Li Ming
Published: February 2011

The problem of delay-dependent dissipative control for nonlinear neutral delay systems is dealt with. We develop the design method of dissipative static state feedback controller such that the closed-loop system is absolutely stable and strictly-dissipative. Sufficient conditions for the existence of the quadratic dissipative controller are obtained by using linear Matrix Inequality(LMI) approach. Furthermore, a procedure of constructing such a controller from the solution of LMI is given. It is shown that the solvability of a dissipative controller design is implied by the feasibility of LMIs.
Dynamic Analysis of Slender Shaft in Twin-Spindle Turning
Authors: Lu Kai Bo , Jing Min Qing , Liu Heng , Cong Chun Xiao
Published: February 2011

Machining slender workpiece is still a technical difficulty. This paper investigates the dynamic behavior of a slender shaft subject to constant feedrate moving cutting forces in twin-spindle turning process. The Euler-Bernoulli theory is used to model the rotating shaft. A dynamic cutting force model is formulated considering the flexibility of workpiece and rigid machine tool. The modal analysis method is employed to solve the dynamic response of the shaft. The parametric influence to the response and natural frequencies of shaft is discussed. Finally, the results are presented and compared between constant cutting forces and deflection-dependent force model introduced in this paper. It is found that there exists a stiffening effect due to the cutting process.
Dynamic Analysis of the Superstructure-Pile Foundation-Soil Interaction System under Earthquake Based on Fuzzy Theory
Authors: Xiong Bao Lin , Lu Chun Jiao
Published: February 2011

Based on frequency domain method, the seismic responses of the superstructure-pile foundation-soil system are studied taking the dynamic soil-structure interaction into consideration. For analyzing the earthquake response of cylindrical pile foundation, earthquake response analysis of three-dimensional system of pile foundation-soil-superstructure simplify two-dimensional question. The dynamic responses of the interaction system under EI-Centro ground motion excitation are evaluated by using secondary development of the large general finite analysis software Abaqus. It is shown that pile foundation is more anti-seismic and that pile foundation flexibility can improve the structural basic cycle. Based on a comprehensive assessment theory, soil-superstructure interaction problem under Earthquake is analyzed by second-level evaluation of comprehensive evaluation. By applying comprehensive evaluation method fuzzy theory model of soil-superstructure interaction is built. It is show that fuzzy mathematics method is appropriate for this kind of soil-superstructure interaction problem.
Effect of Tempering Temperature on the Compressive Deformation Behaviour of 40Cr after Quenching and Tempering
Authors: Hu Cheng Liang , Zhao Zhen , Zhang Ying , Xu Xiang Long
Published: February 2011

40Cr steel is categorized as quenched-tempered steels and is widely used in gears, bolts, couplings, spindles, etc. To study the plastic deformation behaviour of the steel after quenching and tempering, compression and double-pass compression tests have been carried out. The quenched samples are tempered at the temperature of 540oC, 580oC, 600oC and 630oC, and the microstructures, compression load, hardness after compression and load of double-pass compression are investigated. The compression peak load is higher when the tempering temperature is lower. The hardness average and its increase amplitude decrease with the tempering temperature. An interesting phenomenon of the double-pass compression load can be well explained by the microstructures.
E-Learning in Enterprise Community to Improve Knowledge Innovation
Authors: Wu Bing , Xu Wen Xia , Ge Jun
Published: February 2011

The purpose of this paper is to introduce a general scenario for Enterprise SNS knowledge community of E-Learning to promote knowledge innovation, including four sub processes and two knowledge techniques. First, four sub processes are researched respectively, including: motivation to acquire new knowledge, knowledge searching and collection, knowledge decision-making and knowledge innovation. Second, knowledge base and recommendation are two knowledge techniques. The paper underscores the significance of E-Learning to improve knowledge innovation in enterprise and a case study is given. Keywords: E-Learning; SNS; knowledge community; knowledge innovation;
Fault Detection of Excavator’s Hydraulic System Using Dynamic General Regression Neural Network
Authors: He Xiang Yu , He Shang Hong
Published: February 2011

In order to improve reliability of excavator’s hydraulic system, a fault detection approach based upon dynamic general regression neural network (GRNN) approach was proposed. Dynamic GRNN is an extension of GRNN, which could effectively caputure the dynamic behavior of the nonlinear process. With this approach, normal samples were used as training data to develop a dynamic GRNN model in the first step. Secondly, this dynamic GRNN model performed as a fault determinant of the test fault. Experimental faults were used to validate the approach. Experimental results show that the proposed fault detection approach could effectively applied to the excavator’s hydraulic system.
Fault Diagnosis of Hydraulic Syetem Based on Neural Network
Authors: Tang Hong Bin , Wu Yun Xin
Published: February 2011

Because neural network has the advantages of fast parallel processing, associative memory, self-organizing and self-learning, it is widely applied in the fault diagnosis of hydraulic system. Present in this paper is a fault diagnosis approch to a typical failure in hydraulic system which is leakage of hydraulic cylinder.The fault diagnosis approch is based on monitoring preesure singal,time domain feature and neural network. According to the method, the time domain feature is extracted from the pressure singal and costitutes the eigenvectors at first, then these eigenvectors are input into neural network to identify faults. The experimental results show that three modes of no leakage, slighter leakage and severe leakage are correctly identified and it can be used in the fault diagnosia of hydraulic syetem.
Finite Element Simulation of Large Gap Magnetic Drive System
Authors: Xu Yan , Pang You Xia
Published: February 2011

Numerical computation is processed for the analysis of large gap magnetic drive system driven by traveling wave magnetic field, and magnetic field analysis function of ANSYS software is used as the finite element analysis. Simulating is conducted to get the relationship between permanent magnet’s angular displacement and electrifying state of electromagnet coil. The rules of how main system parameter affect system’s driving characteristic are studied. The simulation is validated by experimental result: Torque capacity of the system can be improved by increasing the number of windings of coil, the electric current of coil, the outside diameter of permanent magnet, the magnetization of permanent magnet, or reducing the coupling distance between electromagnet and permanent magnet. Torque capacity of the system can also be improved by placing the position of electromagnet and permanent magnet in 5mm-10mm relative position in y direction (at both the left and right side).
FPGA Based Excitation Source in Biomedical Electrical Impedance Tomography System
Authors: Chen Xiao Yan , Wu Jia Ni
Published: February 2011

An excitation source for biomedical electrical impedance tomography system based on FPGA is designed and implemented with 33 KHz bandwidth and adjustable phases. Codes are programmed with PicoBlaze instructions by Notepad++, and compiled to user programs by KCPSM3 assembler. Digital-analog conversion is carried out in interruption subroutine, the output digital signals are sampled at the setting frequency and filtered by a second-order Butterworth low-pass filter. The proposed method offers a novel effective and feasible approach to satisfy the requirements of excitation source in bioelectrical impedance tomography system.
An Algorithm for Geometric Modeling and Intersection in NC Milling Simulation Based on Triangular Mesh Model
Authors: Sun Dian Zhu , Kang Xin Cai , Li Yan Rui , Sun Yong Wei
Published: February 2011

To achieve the accurate and efficient NC milling simulation based on the discrete triangular mesh model, we proposed an algorithm for geometric modeling and intersection. We construct the R*-tree index for upper-surface nodes of mesh model, based on which the nodes within cutting region can be obtained. We compute tool path segments within cutting projection region of node, and calculate the minimum adjustment height of node according to tool path segments within cutting projection region and then change the z-value of node. Thus, we complete the intersection calculation in simulation process. It has been proved by examples that the algorithm for geometric modeling and intersection in NC milling simulation has strong adaptation to tool path segment type and that it can accurately and efficiently reflect the effect of NC simulation process based on the discrete triangular mesh model of rough.
Function Area Layout Method of Underground Distribution Center
Authors: Ma Cheng Lin , Mao Hai Jun
Published: February 2011

Function area layout of underground distribution center is an important part of urban underground distribution center planning so that it would indirectly affect the building and development of underground distribution center and even the whole urban underground logistics system. Based on Automod simulation platform, the function area layout planning method was built in order to avoid underground operation invalidation because of the illogical function area layout. First by analyzing relative operation of underground distribution center, multi-objective 0-1 mixed integer programming model of function area layout was built based on two indexes of relativity and transit cost among function areas. Then the heuristic algorithm or exact algorithm was used to solve the mathematical model mathematical model and find out the layout scheme after quantifying the indicators. Finally the final layout was gained by simulation and optimization of Automod simulation platform. There was an example for proving the feasibility of the method. The results showed that the method was available to analyze the function area layout impact and it was very important for decision-making of building the underground distribution center.
Gaussian Noise Filter Using Variable Step Time Matrix of PCNN
Authors: Cheng Yuan Yuan , Li Hai Yan , Xiao Qi , Zhang Yu Feng , Shi Xin Ling
Published: February 2011

A novel method was brought forward for the purpose of filtering Gaussian noise effectively by using variable step time matrix of the simplified pulse coupled neural network (PCNN). Firstly, the time matrix of PCNN, related to the grayscale and spatial information of an image, is calculated to identify the noise polluted pixels. Subsequently, a variable step, a long step for strong noise and a short step for weak noise, based on the time matrix is applied to modify the grayscale of noised pixels in a sliding window. And then wiener filter is used to the image to further filter the noise. Experiments show that the proposed filter can remove Gaussian noise effectively than other noise reduction methods such as median filter, mean filter, wiener filter etc, and the filtered image is smooth and the details and edges are sharp. Compared with existing PCNN based Gaussian noise filter, the proposed filter gets higher Peak Signal-to-Noise Ratio (PSNR) and better performance.
Gaussian Window of Optimal Time-Frequency Resolution in Numerical Implementation of Short-Time Fourier Transform
Authors: Jin Yang , Hao Zhi Yong
Published: February 2011

In this paper, we report the condition to keep the optimal time-frequency resolution of the Gaussian window in the numerical implementation of the short-time Fourier transform. Because of truncation and discretization, the time-frequency resolution of the discrete Gaussian window is different from that of the proper Gaussian function. We compared the time-frequency resolution performance of the discrete Gaussian window and Hanning window based on that they have the same continuous-time domain standard deviation, and generalized the condition under which the time-frequency resolution of the Gaussian window will prevail over that of the Hanning window.
Global Optimization of Tersoff Clusters Using Differential Evolution with Inexact Line Search
Authors: He Yang Jun , Zhang Gui Jun
Published: February 2011

Differential Evolution with Inexact Line Search (DEILS) is proposed to determination of the ground-state geometry of atom clusters. DEILS algorithm adopts probabilistic inexact line search method in acceptance rule of differential evolution to accelerate the convergence as the region of global minimum is approached. More realistic many-body potential energy functions, namely the Tersoff and Tersoff-like semi-empirical potentials for silicon, are considered. Numerical studies indicate that the new algorithm is considerably faster and more reliable than original differential evolution algorithm, especially for large-scale global optimization problem of MBP6/Si(C). Moreover, some ground-state solutions, which are superior to the known best solution given in literature, are reported.
H-Infinite Output Tracking Control for Neutral Systems with Time-Varying Delay and Nonlinear Perturbations: A Less Conservative Result
Authors: Zhong Guang Xin , Xu Zhao Di , Li Xiao Yi
Published: February 2011

The problem of H-Infinite output tracking control for liner neutral systems with time-varying and nonlinear perturbations is investigated. The purpose of this paper is to ontain a delay-dependent sufficient condition to guarantee H-Infinite output tracking performance and a less conservative result. A liner matrix inequality (LMI) approach is adopted to solve the problem.
Identity-Based Convertible Limited Verifier Signature Scheme in the Standard Model
Authors: Shen Xiao Qin , Ming Yang
Published: February 2011

A convertible limited verifier signature (CLVS) can be used to solve conflicts between authenticity and privacy in the digital signatures. In a CLVS scheme, the signature can be verified by a limited verifier. When necessary, the limited verifier can provide a proof to convince a judge that the signer has indeed generated the signature. However, the judge cannot transfer this proof to convince any other party. Also, the limited verifier signature should be converted into an ordinary one for public verification if required. In this paper, we proposed firstly identity-based converible limited verifier signature scheme in the standard model. We give the security proofs of our scheme and show that Our scheme achieved the desired security notions in the standard model (without random oracle).
Immune Computation of Anti-Worm Static Web System
Authors: Gong Tao , Wang Song , Yao Lei
Published: February 2011

A normal model and an immune computation model were modelled to detect recognize and eliminate worms in a static Web system. Immune computation included detecting, recognizing, learning and eliminating non-selfs. The self/non-self detection was based on querying in the self database and the self database was built on the normal model of the static Web system. After the detection, the recognition of known non-self was based on querying in the non-self database and the recognition of unknown non-self was based on learning unknown non-self. The learning algorithm was designed on the neural network or the learning mechanism from examples. The last step was elimination of all the non-self and failover of the damaged Web system. The immunization of the static Web system was programmed with Java to test effectiveness of the approach. Some worms infected the static Web system, and caused the abnormity. The results of the immunization simulations show that, the immune program can detect all worms, recognize known worms and most unknown worms, and eliminate the worms. The damaged files of the static Web system can all be repaired through the normal model and immunization. The normal model & immune computation model are effective in some anti-worm applications.
Intelligent Techniques in Teaching Science of Artificial Immune System
Authors: Gong Tao , Zhou Jia Jia , Qi Lei
Published: February 2011

Building on three theoretical paradigms (student model, ICAI model, and multi-dimension education immune agent), some intelligent techniques are proposed and designed to teach Fuzzy Mathematics and Science of Artificial Immune System in a web-based way. The goal of the teaching methodology is a new learning, which is interactive, sharing, open, cooperative, and autonomous. The great difference between traditional approaches for teaching such knowledge and the new approach in this paper is the centre of teaching. The traditional teaching is centered with teachers but the new teaching is centered with students. The teaching system for Fuzzy Mathematics and Science of Artificial Immune System is a virtual classroom based on the web, and the two courses are designed as web-based courses. Moreover, for Science of Artificial Immune System, the web-based course system is a typical artificial immune system in fact, and students can learn more real knowledge from the web-based course immune system.
A New Algorithm of Online Handwritten Mathematical Formula Structure Recognition
Authors: Hong Liu Rong
Published: February 2011

As a natural, fast mathematical formula input, online handwritten mathematical formula input have great prospects. The paper described the algorithm of recognizing the common online handwritten mathematical formula structure. Firstly, the forms were defined, the convention of formulas were expanded. A method of calculating weight for the minimum spanning tree(MST) was proposed according to the characteristics of hand-written formula. On the basis of them, MST algorithm was applied to formula structural analysis. Then two new algorithms were proposed to recognize the mix form and table structure respectively. Compared with other classical algorithms, the algorithm proposed in this paper can recognized the expansive structure, while recognition rate was improved.
Modeling and Optimization of Hybrid Wind/PV Pumped-Storage Power System
Authors: Ren Yan , Zheng Yuan , Li Yan Pin , Huang Jian Jun , Zhang Dun
Published: February 2011

The hybrid wind/PV pumped-storage power system is to solve the electro-problem of remote and undeveloped areas short of power. Aim to the special physical geography condition of some island, hybrid wind/PV pumped-storage power system is brought forward, which is based on traditional hybrid wind/PV power system, and which storages energy by using pumped-storage. The mathematical models of main components of the system are brought forward. The optimization method is by using improved heredity arithmetic. Aim to the island the system model is brought forward, and the optimization method is applied, which effectively uses wind and solar resource, advancing stability of system, and reducing investment and run/management of the system.
Modeling and Simulation of Visual Tri-Tier Immune System
Authors: Gong Tao , Li Long , Du Chang Xing
Published: February 2011

A visual modelling approach and its computational technique were proposed to represent and simulate a kind of immune system, which is comprised of immune cells and immune molecules etc. To study natural immune system and artificial immune system according to information theories and computational methodologies, the hierarchical model of the immune system was proposed, more faithful and suitable for visual simulation than traditional models. The hierarchical immune system basically consisted of innate immune tier, adaptive immune tier and immune cell tier. Thus, the tri-tier model of the immune system was seamless and coherent with the architecture of the artificial immune system, so that the research on the natural immune system and the research on the artificial one could improve and synchronize each other. Though the structure and features of the natural immune system were difficult to measure and test, the tri-tier architecture and qualitative features of the artificial immune system were built, changed and verified. To validate the new approach to visualize and explore the natural immune system, many experiments were tested on the tri-tier artificial immune system. At last, the visual results of the simulations show that the visual modelling approach can provide an effective and better way of understanding the natural immune system.
Modeling the Sociological Characteristic of Vehicle Mobility in Vehicular Sensor Network
Authors: Yang Wei Dong , Liu Ji Zhao
Published: February 2011

Many mobility models have been proposed for the simulation of vehicular sensor network, however, the existing models seldom consider the sociological Aspects of vehicle movement. The paper firstly analyzed the social characteristic of mobility of the real vehicular traces and gained the conclusion that is short average distance, limited node degree and high cluster coefficient. Based on it, a mobility model based social network is proposed and turned into a simulation, which consists of growing and evolvement of social networks, geographical location mapping of vehicles and node dynamics. The simulation results proved that the model’s characteristic is similar to real trace.
Multi-Agent Consensus with a Time-Varying Reference State and Time-Varying Delays
Authors: Yu Hui , Zhang Yi , Liu Gao Yang
Published: February 2011

This paper is devoted to the study of consensus problem of multi-agent systems with a time-varying reference state in directed networks with both switching topology and time-delay. Stability analysis is performed based on a proposed Lyapunov–Krasovskii function. Sufficient conditions based on linear matrix inequalities (LMIs) are given to guarantee that multi-agent consensus on a time-varying reference state can be achieved under arbitrary switching of the network topology even if the network communication is affected by time-delay. These consensus algorithms are also extended to consensus formation among the agents. Finally, simulation example is given to validate our theoretical results.
New Delay-Dependent Stability Criteria for Systems with Interval Time-Varying Delay
Authors: Xu Dong Sheng , Tian Jun Kang
Published: February 2011

This paper is concerned with delay-dependent stability for systems with interval time varying delay. By defining a new Lyapunov functional which contains a triple-integral term with the idea of decomposing the delay interval of time-varying delay, an improved criterion of asymptotic stability is derived in term of linear matrix inequalities. The criterion proves to be less conservative with fewer matrix variables than some previous ones. Finally, a numerical example is given to show the effectiveness of the proposed method.
Obstacle Detection for Patrol Robot Using Bumblebee2 Stereo Vision System
Authors: Xie Xing Zhe , Wang Heng , Luo Qian You
Published: February 2011

This paper employs Bumblebee2 stereo vision system to detect the obstacles for patrol robot in substation environment. Firstly, with the selected points in the disparity image, the ground plane is calculated by the RANSAC (Random Sample Consensus) algorithm. And then, the local occupancy grid map is built for patrol robot, and the obstacles are detected through connected component analysis method. The actual test in substation environment verified the reliability of the system.
Optimization Analysis of the Mast of Rotary Drilling Rig
Authors: Li Yong Xiang , Luo Hui , Qu Ying Min
Published: February 2011

Aiming at the deformation of the mast of rotary drilling rig, 3D graphics software Pro/E and finite element analysis software Ansys are applied to model and optimize the structure of the mast. Back sliding wheel installed on the mast of rotary drilling rig is firstly proved to be effective to reduce the deformation of the mast of rotary drilling rig. On this basis, the distance between back sliding wheel and the mast of rotary drilling rig, and the position of the pulley yoke are adjusted together to obtain the minimum deformation of the mast of rotary drilling rig, which improves the stability of the mast of rotary drilling rig in the course of construction, and provides theoretic supports for more optimization design and research of the mast of rotary drilling rig.
Optimization of Regional Power Comprehensive Low Carbon Objective Based on Development Degree and Combination Weight Model
Authors: Niu Dong Xiao , Liu Jin Peng , Zhang Qian , Fang Fang
Published: February 2011

The global climate change require human production and life must go into the low carbon times of low energy consumption,low emission and low pollution objectively, and now the low carbon development of electric power industry becomes the important link to realize the aim of energy saving and emission reduction. With the necessity analyses of carbon emission reasonable control in electric power production, this paper first proposed the thought of regional electric power overall low carbon，then comprehensive summary origin measures from generation side, transmission side and consuming side. This paper set up the optimization system of regional electric power low carbon, proposed the development degree and combination weight model to empirical study,which provide the effective theoretical basis for low carbon concrete measures.
Optimum Test Point Selection Based on MADM for Analog Fault Dictionary Techniques
Authors: Chen Xiao Mei , Meng Xiao Feng , Wang Guo Hua
Published: February 2011

a new graph-search algorithm based on multi-attribute decision making (MADM) is proposed. Firstly, A* algorithm is used for graph-search, but when cost functions of two nodes are equal, three attributes describing a node are introduced. Secondly, a multi-attribute decision based on maximum deviation principle is used for nodes evaluation in order to select the best node for expanding. The proposed algorithm could overcome deviation brought by node evaluation based on information theory metrics only, which results in high accuracy. The outcome of simulation verification at the end of this paper manifests that this algorithm has excellent accuracy as the exhaustive algorithm, and is more quickly for large scale computation.
Analysis on Hopf Bifurcation and Complexity of one Kind Financial System
Authors: Zhang Qi , Ma Jun Hai
Published: February 2011

From a mathematical model of one kind complicated financial system, we make a dynamic analysis on this kind of system on the basis of studies of scholars both at home and abroad. We find characteristics of various dynamic systems driven by different parameters, and study possible Hopf bifurcation as well as the relationship between Hopf bifurcation and the values of parameters. Besides, we make use of algorithm to analyze complexity of the system. The results of numerical simulation prove that the theory used in the thesis is correct. This study is regarded with good theoretical and practical value.
Predictive Artificial Potential Field Method and its Application on Robot Soccer Path Planning
Authors: Huang Peng , Miao Chang Yun , Guo Li Jin , Li Ying
Published: February 2011

This paper presents a new predictive artificial potential field approach for robot soccer path planning under complex and uncertain environment. By predicting and analyzing the future position and attitude of concerned object, the position and attitude of the object is controlled by demonstration algorithm. The proposed method is successfully used in the robor soccer shooting and is realized on the MiroSot 3vs3 simulating platform. Experiment results show that this algorithm has good real-time ability and adaptability to environment.
Preparation and Characterization of Steel Slag Adsorbent
Authors: Liu Sheng Yu , Xu Yuan Yuan , Gao Jin , Lu Cheng Wei , Yang Yi Jin
Published: February 2011

Steel slag is a industry solid waste which come from steel making factory，and is easy to solid-liquid separation, so it posses some adsorption capacities and can be used as adsorbent. Adsorption phenol onto steel slag was investigated by the oscillating adsorption experiments and the effect of different operating parameters on these adsorption processes, such as initial concentration phenol and the pH value were studied. The surface characterization were gained by SEM, X-ray diffraction, IR Spectroscopy and BET.
Process Estimated Temperature Model of Molten Steel in LF Based on BP Neural Network Combined with Expert System
Authors: Li Qiang , Cao Gang , Li Jiang , Wang Ning
Published: February 2011

The process estimated temperature model of molten steel is based by analyzing the various factors which influence the rise and fall temperature of molten steel and the arts and crafts process of the production. The model has been used to estimate the temperature of molten steel in LF refining. And results of statistic analysis on estimated temperature show when the deviation of process estimated temperature by this model in LF refining is on more than ±5°C to the measured temperature, the hitting probability arrives at 85%.
Quasi Resonant Direct Power Control of Three-Phase Grid-Connected Inverters in Distributed Generation Systems
Authors: Zhao Fang Ping , Yang Yong , Yuan Yi
Published: February 2011

The paper proposes a quasi resonant direct power control algorithm for three-phase grid-connected inverters without grid voltage sensors in distributed generation systems. According to the active and reactive power references, grid virtual flux and the inverter output current references are calculated. In order to accurately and fast track the output current references, the quasi proportional resonant (QPR) controller is used. The theoretical principle of this method is discussed. The steady-state and dynamic experimental results of quasi resonant direct power control that can illustrate the operation and performance of the presented control strategy are displayed. It is shown that the control system exhibits several advantages, such as constant switching frequency, sinusoidal grid currents and good dynamic response. Experimental results are provided to demonstrate the effectiveness of the proposed control strategy.
Rapid Locking Assembly Variant Design Based on Product Configuration Model and CBR
Authors: Nie Yong , Yin Guo Fu , Zhao Xiu Fen , Fang Hui , Yin Ying
Published: February 2011

Aiming at rapid response to requirements of mechanical transmission products customization, a system for rapid locking assembly variant design was proposed in terms of features of locking assembly. The bases of the system are Product Configuration Model (PCM) and Case-Based Reasoning (CBR). According to the system, PCM of locking assembly was built by extending traditional Generic Bill of Materials (GBOM). In addition, integration of PCM and CBR was completed by combining method of transforming PCM to a case with similarity assessment algorithm. Moreover, a rapid variant design software system based on PCM and CBR for locking assembly was developed. Finally, the software system was applied to design new locking assembly. Results demonstrate that it is effective for PCM-CBR to support rapid response to customization.
Rapid Method for Point Clouds Registration Based on Reference Points
Authors: Yang Hou Jun , Zhang Wei Zhong , Liu Xiao Lie
Published: February 2011

Incremental point clouds registration is studied in this paper. A rapid method for point clouds registration based on reference points is proposed, which consists of the coarse registration and fine registration. Firstly, a set of reference points is applied as an assistant utility to measure the object. The transformation parameters are estimated by using the reference points only for coarse registration, and then dense point clouds data will be transformed to the same coordinate system. Secondly, taking the coarse registration results as the initial value, the improved Interactive Closest Point (ICP) algorithm is used in fine registration the original corresponding points are established rapidly by using the k-d tree searching algorithm. Finally, Preview Model Parameters Evaluation Random Sample Consensus (PERANSAC) algorithm is utilized to remove outliers. The experimental result shows that this method in finding original corresponding points can greatly improve the computation efficiency and also improve the registration accuracy.
Regularity of Bézier Curves
Authors: Meng Qing Xian , Liu Hui Li
Published: February 2011

Regularity is one of important properties of curves in computer aided design. In this paper, we convert the problem of determining regularity of Bézier curves to that of detecting existence of zero points of polynomials. Based on the properties of algebraic equations and isolation theorem of roots, a simple and practical method is presented. Regularity of Bézier curves and number of singular points can be determined by easier computation.
A New Method of Rapid Linearity Detection of LFMCW Radar
Authors: Wang Yong Li , He Chun Han , Ren Kai Chun , Zhang Xing Qi , Zhang Xiao Chun
Published: February 2011

Linearity of VCO directly impacts on the range resolution of LFMCW radar, therefor, a linearity correction based on linearity detection is usually adoptted in practical applications. This paper proposes a new method of rapid linearity detection of LFMCW radar. First, estimate and correct the instantaneous phase. Then, fit a straight line for the instantaneous phase of difference frequency signal by least square approximation algorith. Finally, estimate the instantaneous Frequency-Modulation rate of FM signal. Simulation results show that the method is valid.
Remote Monitoring System Design of Distribution Transformer Operating Status Based on GSM
Authors: Yang Yong Ming , Duan Xu , Liu Xi Liang
Published: February 2011

In this paper, a remote Distribution Transformer (DT) monitoring system is presented and developed to solve the problems of existing remote monitoring system wiring too much, too complicated, fault diagnosing and maintaining difficulty. The system hardware design based on 16 bit PIC18F458 chip and GSM module TC35i is proposed. The system software design with MySQL and Visual C++6.0 are discussed in detail. A real-time monitoring of parameters such as three-phase voltage, current, power factor and transformer temperature is finally realized. Experiment results show that the system possesses accurate data gathering, strong anti-interference and good operation performance.
A Comprehensive Mechatronic Modeling and Simulation of Electric Power Steering System
Authors: Rezaei Hamed , Sadjadian Houman
Published: February 2011

Electric power steering (EPS) systems are rapidly replacing existing traditional hydraulic power steering systems due to their important advantages such as fuel and cost savings, environmental compatibility and flexibility. Many articles are available in this field in which EPS is viewed only from one specific aspect. Other aspects have been introduced only by brief equations neglecting some main details regarding the important effects of ignored parts. Therefore, it is quite necessary to make a complete analysis of every part of this system with a right combination between them. It makes a comprehensive simulation system for EPS. This matter needs sufficient knowledge in mechanical, electrical and control sciences and how to assemble them with each other properly. Therefore, Mechatronic is the most appropriate branch of science to achieve this goal. In this paper, a complete model of EPS is presented which includes a 7-D.O.F mechanical model of steering system. A Permanent Magnet Synchronous Machine (PMSM) is used to supply the assist torque to steering column. Vector Control Method is utilized for controlling the motor. A PID controller determines the reference assist torque value. The results are presented to estimate the model precision and evaluation of model.
Research of Robot Gait Based on Evolution Algorithms
Authors: Piao Song Hao , Wang Xian Feng , Zhao Wen , Zhong Qiu Bo
Published: February 2011

In this paper, a new gait research for humanoid robot is presented. By computing the trajectory of center of mass (CoM) for humanoid robot, trajectory of hip joint and ankle joint are developed based on 3D inverted pendulum model. The actual location of the waist position obtained by multi-link model through the center of mass for humanoid robot is in coordinate of the waist of humanoid robot. Trajectory of hip joint and ankle joint are calculated. This paper presents a gait generation method with curve fitting. Using genetic algorithm, humanoid robot can autonomously search for a good gait trajectory. The experimental results show that gait trajectory for humanoid robot can be generated by applying to genetic algorithm. Our proposed method is verified satisfactorily.
Research of Space Electronic Circuit Optimization Design
Authors: Yan Xue Song , Wu Qing Hua , Hu Cheng Yu , Liang Qing Zhong
Published: February 2011

During the space electronic system in carries out the exploratory mission in the deep space, it maybe faced with kinds of violent natural environment, to electric circuit's performance, the volume, the weight and the stability proposed a higher request, the traditional circuit design method already more and more with difficulty satisfied this kind of request. The traditional circuit design method already more and more with difficulty satisfied this kind of request. But unifies the programmable component and the evolutionary algorithms hardware may the dynamic change hardware's structure adapt the adverse circumstance, resume the damage of the function, the adaptation for the duty change. In view of the Xilinx Company's FPGA unique feature, proposed one kind of evolutionary algorithms which uses in the space electronic system circuit optimization design and through the experiment proved, the algorithm obtains the circuit structure to surpass the tradition circuit design method.
Research on Dynamic Simulation of Former Fuselage Assembly
Authors: Cao En Long , Zhang Jian Dong
Published: February 2011

Considering general weakness in the current development of assembly, the paper analyses the structure of former fuselage and the function of assembly. After a thorough investigation and research on extensive analysis, this paper completes three-dimension structural design of former fuselage assembly using digital flexible assembly technology. The three-dimension structural design includes the design of transmission, the design of power sector and the design of actuator combining innovative design methods. The paper completes modeling of front fuselage assembly based on the modular design thought. The module mainly includes the base module, the guide module, the driver module, the execute module and the connection module. And then, the paper accomplishes overall tooling of front fuselage assembly and collision analysis of assembly by using CATIA software. Finally, the paper also completes making the animation by using 3DVIA Composer software. The animation depicts the movement of former fuselage assembly and completes the dynamic simulation.
Research on Fault Diagnosis for Petrochemical Running Equipments Based on ICA
Authors: Chen Zhi Gang , Lian Xiao Jiao , Zhou Ming
Published: February 2011

For solving the difficulty of feature signal extraction from vibration signals, a new method based on Independent Component Analysis (ICA) is proposed to realize separation and filtering for multi-source vibration signals. Firstly, the principal and algorithm of ICA used to separate mixed signals is introduced. Secondly, application in signal separation and filtering with ICA is studied in diagnosis. In addition, imitation and field examples are given. The experiments show it is feasible to separate and extract feature signal from multi-source vibration signals and it is an effective method in signal preprocessing in fault diagnosis.
Research on Intelligent MCAD/CAPP/CAFD Integrated System Modeling
Authors: Chen Hui Fang
Published: February 2011

Feature extraction and expression of three-dimensional MCAD entity model is independent of platform. According to STEP, this paper discusses for a unified MCAD / CAPP / CAFD integrated system to establish the program model and study the key technologies. The STEP neutral file that contains the model is taken to decide the design features of the part. The identification of geometric features and geometric characteristics of features to the mapping process, rule-based reasoning and case-based reasoning with the way things feature-based process planning techniques in the process of reasoning problems. UML object-oriented technology and methods such as functional analysis of the system and structural design, the initial mode of integrated system functional model and structure is established
Research on Room Temperature Control of High Accuracy Constant Temperature Room Based on Cascade Control
Authors: Fu Yun Zhun , Zhang Xu
Published: February 2011

DMC-PID cascade control strategy was adopted to apply on high accuracy constant temperature air conditioning system because constant temperature room had large inertia, delaying, a few interference factors characteristics. The construction type of DMC-PID cascade control system was designed and the prediction model of inner loop and outer loop was determined, and then MATLAB software was applied to simulate and compare robust stability, tracking performance, anti-jamming capability characteristics of DMC-PID cascade control algorithms with other algorithms. Through studies, the overshoot of DMC-PID cascade control of room temperature reduced 2% in comparison with the PID algorithm, but was much larger than that of DMC algorithm. Its regulation time was nearly the same to that DMC algorithm, but cut down 25% in comparison with the PID algorithm. At last, the simulation result showed DMC-PID cascade control strategy application on temperature control of high accuracy constant temperature room had feasibility and effectiveness, and the control strategy had strong robust stability, tracking performance, anti- disturbance ability characteristics.
A Novel Hybrid Model for Image Classification
Authors: Xu Jie , Zhu Rong , Hong Bo
Published: February 2011

Image classification poses challenges to retrieval technology. Though the Support Vector Machine (SVM) has been successfully applied to pattern recognition, its performance is limited by the feature space and parameters in the training process. Our work thus has two central themes. Construct the optimum feature space for training SVM from image features extraction by nonlinear dimensionality reduction based on manifold learning, and meanwhile establish the RBF kernel based SVM classifier by training with the best parameters with a global search capacity of the Quantum-behaved Particle Swarm Optimization (QPSO). Experiments show that our model not only improves the learning ability, but also significantly enhances the accuracy of image classification.
Research on the Machining Method of Ultrasonic Vibration Cutting Machine
Authors: Li Ji Gang , Ji Xue Hua , Wang Bo , Kang Yu , Guo Chao Ying
Published: February 2011

This paper presents a basic principle of ultrasonic vibration metallographic sample cutting machine. Ultrasonic vibration cutting machine contains four parts: the ultrasonic generator, the transducer,the horn and the tools. The cutting machine uses ultrasonic fregnency as the tool of small amplitude vibration.It is a special processing because the surface of the work piece material is gradually broken by the beating of the ultrasonic frenquency and the abrasice which wonders in the liquid that is among the workpieces. The results indicates that the method can effectively improve the quality of surface and precision of the processing surfaces of workpieces.
Research to Safety Evaluation Expert System of Hydraulic Engineering Metal Structures
Authors: Yang Guang Ming
Published: February 2011

Combining the successful applications in AI, in this paper, an expert system is studied and designed for evaluating the safety of hydraulic metal structures, whose goal is compute the reliability of hydraulic metal structures. Applying the techniques of AI, a framework is made up for evaluating the safety of hydraulic metal structures. The framework of knowledge base system is designed and presented with the domain knowledge. Based on the theory of relational database, the conceptual and logical views of database system are designed and analysed. Additionally, method base system is designed. A practical example is given to illustrate the process of using this system. This system has features of practical and advanced and expand.
Research on Seismic Performance of Prestressed Precast Reinforced Concrete Intelligent Structure
Authors: Han Jian Qiang , Li Zhen Bao , Song Xiao Sheng
Published: February 2011

This thesis studies deeply the crack development characteristics, failure pattern, hysteresis curve and the displacement ductility of this new prestressed precast reinforced concrete intelligent structure, by analyzing one prestressed precast reinforced concrete frame under low reversed cyclic load test. Prestressed precast reinforced concrete frame is a new assembly architecture intelligent structure. We build a model using finite element analysis software to the test piece model analysis, the analysis result agree well with the experimental results. Experimental studies indicate that this new prestressed precast reinforced concrete intelligent structure has a good seismic performance. This prestressed precast reinforced concrete frame is a new kind of structural system complying with the development of architectural industrialization, which is worthy of popularization and application in the earthquake area.
Statistical Analysis of Reliability Field Data in CNC System
Authors: Li Ting , Zhong Yu Ning , You Da Zhang
Published: February 2011

Based on reliability field data of failure in the CNC system (Computer numerical control), failure spots, failure patterns and failure mechanism of the key parts in the CNC system was analyzed. According to the field data of reliability, the key subsystems of frequent failure were discovered through statistical analysis and criticality analysis. The fault tree was established, then the weak part of reliability was point out, and the basis for its reliability improvement was provided.