bluuebunny/crossref_metadata_2025 huggingface dataset:
A Design of Pulse-Wave Data Collection System
Authors: Zhang Xiao Hui , Zhao Xi Ling
Published: October 2011

In this paper, a newly design of pulse-wave data collection system continuously and non-invasion by using the means of clip-on transmission oxygen sensor for getting information of pulse-wave, using the wave can calculate a number of important parameters of blood, it may solve the problem of real-time, continuous and dynamic blood flow monitoring in clinic, This design use sensor to get photoelectric volume pulse wave then the signal through amplification and filter circuit ,after then it is sent to A / D converter and DSP. The powerful instruction functions and fast processing speed DSP makes this design can quickly and easily detect the pulse wave signal. This design not only used for clinical care, but also can be used for community or family health care on detection of cardiovascular blood flow. This design can make the telemedicine care ture by DSP and the PC communication, It provides a simple and easy method to monitor the pulse-wave signal .
Research on PID Control Model for Error Compensation in Milling Thin-Wall Parts
Authors: Zhu Lei , Lu Jun , Liu Yan
Published: October 2011

Accuracy of machined components is one of the most critical considerations for any manufacturer. To improve the accuracy by diminishing errors in CNC milling thin-wall parts, this article analyzes sources of errors and provides PID control model to error compensation, namely acquiring offset value by calculating the coefficients of proportional, integral and differential and corresponding errors, and then adjusts codes of next processes. The effectiveness of PID control model in improving accuracy is testified by experiments contrasting with groups of non-compensation and completely-compensation. The experiments have proved that PID control model of CNC milling thin-wall parts can predict machining error trends and have advance regulation.
Study on the Residual Stress Test of Welded Joints for Wind-Driven Generator Base and Numerical Analysis
Authors: Shen Yu Long , Liu Ji Pu , Shi Yi Xin , Dai Bo , Su Liang , Ma Wen Bo
Published: October 2011

In order to know the concrete distribution of welding residual stresses in Megawatt wind turbine’s basis, Msc.Marc codes by finite element method were applied to simulate temperature and stress field of the base’s welded joints which were appeared on the screen by 3D real-time dynamic numerical, the distribution of welding temperature field and the residual stress is obtained and then the test results of welding residual stress are checked by Blind-hole method. The welding residual stress in the condition of anneal and non-anneal was comparatively analysed. The results show that the transverse and longitudinal residual stresses in the area near the weld are comparatively larger, and the variation trend of the transverse and longitudinal residual stresses in the area far away from the weld are nearly the same. It means that the FEM determination results coinciding with test results are available for reference to the design of the Wind-driven generator welding structure.
Experiment Study on Micro-Hardness and Structure of NC Grinding Surface Layer of Spiral Bevel Gears
Authors: Ming Xing Zu , Yan Hong Zhi , He Guo Qi , Zhou Jing
Published: October 2011

Through the analyses of experiment,mechanism of dislocation and coupling of grinding temperature and deformation field,many conclusions are gotten.Firstly,a tempering metamorphic layer of lower hardness is formed in hardening zones of grinding layer of spiral bevel gear. Secondly,the microstructure of grinding tooth surface is acicular martensite+residual austenite+ a small amount of carbides,and it’s outside to the inside presents the variation of "fine→coarser→finer".Thirdly, the critical condition of grinding burns is obtained,that is when grinding temperature is above 600°C,metamorphic layer depth is greater than 0.2mm or more. The formation characteristics of grinding cracks is also revealed. These provide a basis for the NC grinding quality control of spiral bevel gears.
The Optimization of Equipment in Greenhouse for Seedling Production in South Area of Guangxi Province
Authors: Su Chu Wang , Mo De Yun , Wei Chao Yi , Tang Xian Ming
Published: October 2011

The concept of largest photosynthesis of unit costs on seedling production was constructed. The main structures of greenhouse and the cladding rate of cladding nets for different top layer cover materials and the equipment of supplement light in winter on eucalyptus seedling production in south area of Guangxi province was optimized. The results of this paper show that the greenhouse with highest quality-price ratio was the plastic greenhouse equipped with the fan pad and 60% cladding rate was the best for glass material in top cover layer, while 50% cladding rate was the best for wave board or plastic layer and. the agricultural sodium lamp was the best light source for supplement light in winter.
A New Numerical Scheme for Linear Scalar Conservation Laws
Authors: Chen Rong San , Liu An Ping , He Shui Ming , Hu Xin Li
Published: October 2011

In this paper, we develop a numerical scheme with the fifth-order polynomial reconstruction satisfying two conservation laws for the linear advection equation. The scheme is the Godunov type, and has two numerical entities, numerical solution and numerical entropy. Numerical experiments show that the scheme is more robust in long-time behaviors than that of [8].
Study on Operation Control Strategy of Single Piston Hydraulic Free-Piston Diesel Engine
Authors: Guo Feng , Huang Ying , Zhao Chang Lu , Liu Jia , Zhang Zhen Yu
Published: October 2011

The operation control strategies of free-piston engine are investigated in this paper. To start the engine, it needs to adjust the compression pressure and the reset valves should cooperate with the frequency control valve to avoid squirm of the piston for hydraulic leakages. The reset valves should be closed before frequency control valve is opened. A piston position feedback modulation control method which can make sure the piston accelerated continuously is presented. It has fixed frequency control valves open signal moment but no fixed frequency control valves closed signal moment, and the closed signal was activated by piston position feedback.
Diagnosis for Vibration Fault of Steam Turbine Based on Modified Particle Swarm Optimization Support Vector Machine
Authors: Shi Zhi Biao , Song Quan Gang , Ma Ming Zhao
Published: October 2011

Due to the influence of artificial factor and slow convergence of particle swarm algorithm (PSO) during parameters selection of support vector machine (SVM), this paper proposes a modified particle swarm optimization support vector machine (MPSO-SVM). A Steam turbine vibration fault diagnosis model was established and the failure data was used in fault diagnosis. The results of application show the model can get automatic optimization about the related parameters of support vector machine and achieve the ideal optimal solution globally. MPSO-SVM strategy is feasible and effective compared with traditional particle swarm optimization support vector machine (PSO-SVM) and genetic algorithm support vector machine (GA-SVM).
Modeling, Analysis and Optimization of Three Degree of Freedom Automobile Handling and Stabilities Model
Authors: Yu Lei Yan , Zhao Wan Zhong , Jin Yue
Published: October 2011

Handling and stabilities is important for steer by wire (SBW) system. Firstly, a platform for SBW handling and stabilities analysis and parameter optimization with friendly graphic user interface (GUI) is built based on Matlab GUI technology. Secondly, three degree of freedom handling and stabilities model with steering angle as input is built and system stability is analyzed based on Routh-Hurwitz stability and poles methods. Then simulations are carried out to show effects of some vehicle parameters on handling and stabilities. Finally, the handling and stabilities sensitive parameters are optimized using genetic algorithm method to improve step responses and handling and stabilities.
Modified Projective Synchronization of Chaotic Systems with Unknown Parameters
Authors: Yan Min Xiu , Fan Li Ping
Published: October 2011

This paper proposes the modified projective synchronization of uncertain chaotic systems with unknown parameters via active adaptive sliding mode control (AASMC). The disturbances are considered both in the drive and the response system. The bounds of the disturbances are unknown. The adaptive updating laws are designed to tackle the unknown parameters. Moreover, the robustness and stability of the proposed AASMC is proved by the Lyapunov stability theory. Some numerical simulations are given to demonstrate the robustness and efficiency of the proposed scheme.
Research on Extracting Cyclostionary Statistics of Amplitude-Modulated Signals Based on Cumulant
Authors: Shang Tie Jun , Fu Xian Jie , Liu Li , Feng Zhi Peng , Hu Nai Lian
Published: October 2011

Regarding the cyclostationary of of amplitude-modulated signals, a method for extracting cyclostionary statistics of amplitude-modulated signals based on Cumulant is proposed. An index, energy ratio coefficient is defined to assess signals modulated degree. Theoretical data and Simulation data are analyzed, and it is found that the energy ratio coefficient increases with the increasing modulated degree.
Research on Mathematic Model and Measuring Method of Moving Beam Attitude in Large Forging Hydraulic Press
Authors: Chen Hui , Tan Jian Ping , Gong Jin Li , Cao Xian Yue , Zhou Ji Neng
Published: October 2011

The moving beam of large forging hydraulic press is taken as a research object. A mathematic model of moving beam’s six freedom degrees attitude is established. According to the mechanical feature and special working conditions of large forging hydraulic press, a non-contacted method for moving beam attitude measuring which based on machine vision is proposed. The basic principle and composition of the system are introduced. The system is applied in 300MN large forging hydraulic press, and large amounts of monitoring data are collected which confirm that the measuring method is effective. The research result is helpful for the safety operation and maintenance of large forging hydraulic press.
The Simulation Analysis of Tool Orthogonal Rakes Affecting Metal Cutting
Authors: Wan Xiao Hang , Dong Zhao Wei , Li Shu Jun , Liu Sheng Yong
Published: October 2011

Adopted the theory of elastic-plastic deformation, used the FEM analysis software, the reasonable two-dimension heat-mechanic coupling orthogonal cutting model is established in this paper, which uses the adaptive meshing criteria and simulates a typical work-piece chip breaking process. This paper simulates different tool orthogonal rakes how affect the cutting process, which is very significant in engineering. This paper supplies the theory foundation of optimizing the technical parameters and deeply studying the cutting mechanism.
Research on an Improved Self-Correcting Location Algorithm for Wireless Local Region
Authors: Zhang Zheng , Jiang Min , Wan Guo Cheng , Liu Xiao Wei
Published: October 2011

Node position technology is an internal demand of wireless sensor network, however, in most project account; it’s hard to obtain the nodes' exact position because of uncontrollability in the network deployment process. For this purpose, an improved self-correcting location algorithm which based on RSSI multilateral ranging was proposed in this paper. Other than the primary multilateral localization algorithm, a correcting node which adjacent to the blind node was imported into the pending location region. The main function is to reduce the influence caused by unilateral ranging error in the calculation of multilateral positioning and improves the positioning precision. Detailedly introduced the principle of self-correcting location algorithm, moreover, in order to check the improved algorithm’s location performance, a back testing was done via CC2430/CC2431 wireless nodes. Test results show that improved algorithm enhances the system’s accuracy and stability.
Software Design of Networked Virtual Instrument System
Authors: Chen Guo Shun , Lv Yan Mei , Xia Ming Fei
Published: October 2011

Based on the functions and performance analysis of networked virtual instrument (NVI) system, this paper design and implementation the software system of a NVI with the .NET platform. And carry out an in-depth analysis of the software system, especially the key techniques including databases, DataSocket and multithreading. The system uses ASP.NET, C# for development server pages, the instrument operation instructions embedded in Web pages using ActiveX techniques. Using VC to development VI server applications, and through DataSocket to transfer testing data. The testing results show that the software system is operating well, the NVI system achieves a convenient user and testing resource management, and making the system more users to share testing equipment to improve efficiency.
Comparison of Detrending Methods in Frequency Domain Analysis of R-R Interval Series
Authors: Li Li Ping , Liu Chang Chun , Li Ke , Liu Cheng Yu
Published: October 2011

Non-stationary trend in R-R interval series is suggested to be removed to obtain reliable results for it could highly influence the frequency domain analysis of heart rate variability. In this study, three detrending methods, the smoothness prior approach, the wavelet and the empirical mode decomposition, were compared on artificial R-R interval series with four types of simulated trends. The Lomb-Scargle periodogram was used for frequency domain analysis. Results indicated that the wavelet method showed a better overall performance than the other two methods, and more time-saving, too. Thus the wavelet method is recommended as an optimal choice for use.
Design and Precision Analysis of Muzzle Angle Measurement System
Authors: Zhou Jian Ping , Wu Xiao Yun , Zhang Peng Fei , Gu Guo Hua
Published: October 2011

The traditional muzzle angle measurement method measured by optical range quadrant can’t satisfy the demand. A muzzle angle auto-measurement method based on collimation light source and PSD two-dimension sensors is provided. Adopted by the auto-measurement technology, the precision, efficiency and velocity of measurement are all improved, which solves the problems of traditional methods. The errors and precision of the new system are analyzed. According these analysis and calculation, the precision of this measurement system can gain the measurement ends.
Design of Elastic Cell in Pressure Sensor
Authors: Ye Feng , Wang Zhong Ming
Published: October 2011

The theory of sheet model is used to design the elastic cell of pressure sensor. In this model, the elastic cell shapes like a disk; the ratio of diameter to thickness is in the range from 0.01 to 0.2. According to the calculating result, an elastic cell made by 40CrNiMo with diameter 11mm and thickness 1.6mm can test the pressure form 0 to 100MPa. It is similar with features of calculating result and works well in test.
Dynamic Optimization Design of Engine Crankshaft
Authors: Cui Zhi Qin , Zhang Teng , Wang Xiao Hua , Xu Zhao Hua
Published: October 2011

With the constant improvement of the engine enhanced index, the crankshaft working conditions are even more critical. For designing a better dynamic performances of crankshaft, dynamic optimization design of crankshaft is researched. Boundary restrictions and dynamic loading conditions that simulate the actual ones are exerted on the finite element model of the crankshaft and its dynamic responses are calculated. Based on the sensitivity analysis method, the to-be-modified parameters are selected from the parameters which vary the dynamic properties greatly. With this method, the dynamic properties of the modified crankshaft could satisfy the design requirements, and lays a solid foundation of the dynamic optimization designing of complete engine.
Experiment Study and Design of Measurement System of the Total Electrical Field on the Ground Level under HVDC Transmission Lines
Authors: Zhao Xin Rui , Lu Tie Bing , Dong Yu Hong
Published: October 2011

Based on the technology of virtual instrument, a set of measurement system of the total electric field on the ground level under HVDC transmission lines is developed. After the hardware and software system are built up, some tests are made in laboratory to show the validity of the system. Finally, experiment results are given and analyzed. The developed measurement system can be used to measure the total electric field on the ground level under HVDC transmission lines, and can provide support for the evaluation of the electromagnetic environment of the HVDC transmission lines.
The Research and Design of Portable Leaf Disease Spots Image Acquisition System
Authors: Song Kai , Wang Zhe , Shen Feng Ju
Published: October 2011

The crop leaf disease spots image recognition technology has a great significance in identifying diseases and in effective spraying of pesticides to liminate diseases. We researched and designed the portable leaf disease spots image acquisition system since current PC-based processing system is high cost and lack of flexibility and real-timing, This system uses a high-performance 32-bit DSP chip based DM642 as its main processor, and also uses ultra-low power consumption and ultra-small size video decoder chips, large-capacity memories and high-performance communicator interfaces. As a result of the reasonable design of hardware architecture, this system realized leaf disease spots image features collecting and processing ，video transmitting, and achieved strong real-time processing capability, easy operation, low cost, anti-interference ability and other characteristics. The system prototype works well, and meets the design requirements.
New Estimations of Bounds for the Chu Chaotic System
Authors: Jian Ji Gui , Wang Wei Wei
Published: October 2011

This paper is concerned with positive invariant set for the Chu chaotic system using a technique combing the generalized Lyapunov function theory and maximum principle. For this chaotic system, some new ellipsoid estimations and a cylindrical domain estimation of the globally exponentially attractive set for all the positive parameters values of the system are derived without existence assumptions via employing inequality techniques and the continuous extension principle.
Spectral Data Modeling Based on Feature Extraction and Extreme Support Vector Regression
Authors: Liu Shao Wei , Yan Dong , Liu Zhi Hua , Tang Jian
Published: October 2011

Spectral data such as near-infrared spectrum and frequency spectrum can simply the modeling of the difficulty-to-measured parameters. A novel modeling approach combined the feature extraction with extreme support vector regression (ESVR) is proposed. The latent variables space based feature extraction method can successfully complete the dimension reduction and independent variable extraction. The novel proposed ESVR leaning algorithm is realized by using extreme learning machine (ELM) kernel as SVR kernel, which is used to construct final models with better generalization. The experimental results based on the orange juice near-infrared spectra demonstrate that the proposed approach has better generalization performance and prediction accuracy.
A Damage-Coupled Time-Dependent Multi-Axial Fatigue Failure Model for Solder Alloy 63Sn-37Pb
Authors: Luo Yan , Gao Qing
Published: October 2011

Based on the time-dependent deformation behavior of solder alloy 63Sn-37Pb at room temperature, a damage-coupled unified visco-plastic multi-axial fatigue model and its failure criterion were proposed. In the evolution equation of damage for the model, the time-dependent effect of damage was taken into account. The model was used to predict the fatigue life under different loading paths. The comparison between the predicted and experimental results demonstrated that the time-dependent failure model can simulate the deformation behavior and predict the fatigue life well under different nonproportional strain paths.
A Frequency Tracking Method Based on Improved Adaptive Notch Filter for Coriolis Mass Flowmeter
Authors: Yang Hui Yue , Tu Ya Qing , Zhang Hai Tao
Published: October 2011

Adaptive notch filters (ANF) are known have non-absolute convergence problems which will lead to precision reduction in long-playing frequency tracking. In this paper, we propose an improved ANF based on Steiglitz-McBride method (SMM) for Coriolis mass flowmeter (CMF) whose frequency, amplitude and phase are time-varying based on the random walk model. An monitor is designed to monitor whether the frequency is estimated rightly or the ANF just filters noise. If the frequency of CMF’s signal is missed, we will modify the parameters and restart the ANF to resume the search for the correct frequency again. The particular algorithm of the improved ANF is also put forward. Simulations have verified the effectiveness of the presented method in tracking CMF’s frequency, which shows superior performance comparing to the primary SMM based ANF.
A Side-Coupled Optical-Fiber Liquid Level Sensor
Authors: Zhao Cheng Rui , Ye Lin , Ge Jun Feng , Cheng Yi
Published: October 2011

A side-coupled optical-fiber liquid level sensor is proposed to realize intrinsically safe measurement to liquid level in flammable environments. The sensor consists of two parallel side-polished fibers is based on the different coupling coefficient between the fibers in different media according to the Fresnel equation. One of the fibers is for emitting and the other is for receiving, and a reflector is attached to the end of the fibers to enhance the power of light. The power of the light from the top of receiving fiber is measured by the signal processing circuit which is mainly organized by an instrumentation amplifier and a correlator. This sensor is fabricated in the laboratory and the results of the experiments show good performance. It is demonstrated that the sensor is safe and sensitive, but there is still a lot of work to do before its commercial usage.
An Autonomous Predictive Centroiding Algorithm for Star Sensor
Authors: Li Bao Hua , Li Jing , Chen Xi Jun
Published: October 2011

Of all current methods for measuring spacecraft attitude, the use of star sensors produces the most accurate measurements. Conventional star sensors repeat these processes with Lost-In-Space case. To advance the methods available to solve these problems, this paper presents an autonomous predictive centroiding algorithm for the star sensor. The star sensor works in the star predictive centroiding case while few recognized stars within the FOV (Field of View). The ideal locations of unrecognized stars and recognized stars in star image are predicted at first. Then the corresponding real locations of recognized stars and unrecognized stars are obtained in the threshold scan window of predictive centroiding. It enables only several hundred pixels to be scanned. The speed and the accuracy of this algorithm are successfully demonstrated in comparison with the ordinary centroiding algorithms which don't use the previous image data. Finally the autonomous predictive centroiding algorithm was successfully demonstrated with real sky experiment in 2008 and on-orbit in 2010.
Applying Ad Hoc Network on Unknown Environment Detection
Authors: Wang Hai Tao , Jia Zong Pu , Zhao Qian
Published: October 2011

Wireless Ad Hoc Network is a distributed self-organizing networking with no infrastructure and central control. To probe the unknown environment and obtain the associated data, this paper offers a Multi-Strategy Data Transmission Scheme (MSDTS) for Ad-hoc network based on link queue, alternate node and ferry transmission. This kind of scheme has good performance on building link Ad-hoc network, data drop rate, average throughput of network.
Practical Technologies Research of Line Structured Light Three-Dimensional Profile Measurement at Low-Cost
Authors: Fu Li , Cheng Tao , Zhou Yuan Dong
Published: October 2011

In this paper, a new method for determining the integrity of the image element of the target was proposed based on the self-made low-cost line structured light three-dimensional measurement platform, and BP neural network was used to complete the calibration of line structured light camera system. At the same time, Gaussian model for the four direction were constructed , which speeds up the extraction speed for the laser stripe center based on the gray gravity method of skeleton, and the point cloud data is deal with the refinement, noise removing, smoothing and three-dimensional reconstruction, which complete the task of product three-dimensional contour detection.
Reducing False Negatives in Intelligent Intrusion Detection Decision Response System
Authors: Kai Hong Mei , Liu Xiao Jie , Liu Ya Fei , Zhou Lin
Published: October 2011

As soon as the Intrusion Detection System (IDS) detects any suspicious or malicious activity, it will generate alarms. Unfortunately, the triggered alarms usually are accompanied with huge number of false alarms (false-positives and false-negatives) which is the key performance parameters of the IDS. The risk of false-negatives is higher than false-positives. In our previous paper, we proposed a novel intelligent intrusion detection, decision, response system (I2D2RS) with fuzzy theory, which use the two essential information times and time, of the failed login to decide automatically the attacker like an experienced system/security administrator. Though the system can reduce the false alarms perfectly, the capability of processing simultaneous multi-point attack is relatively weak, and then false-negatives will be occurred. In this paper, we employ a preprocessing module to collect the failed login information before data processing. The proposed approach changes the processing procedure from serial to parallel processing, thus eliminates the false-negatives. The efficiency of these improvements was confirmed with the experiments.
Research on Operational Model of New-Generation GPS Based on Dynamic Description Logic
Authors: Xia Xue , Zhong Yan Ru , Qin Yu Chu , Ji Liu Jing
Published: October 2011

Operation and Operator are the key technologies in the new-generation geometrical product specification and verification (GPS). In order to solve the geometrical specification problems of product functional requirements and the ambiguity problems of product specification, this paper utilizes a new method based on dynamic description logic to describe the fundamental concepts of geometrical specification. It analyzes the geometrical features of geometrical product functional specification. By establishing the model of the operations, describing the input and output parameters in the specification and verification process, and analyzing the preconditions and results of the executions of specification operator and verification operator, the paper simplifies the operation results and overcomes the shortcomings of ambiguity and inconsistency in product specification process. Finally, it takes the specification process of perpendicularity as an example to prove the feasibility and validity of this method.
A Study of MRife Algorithm and CSB Algorithm on Frequency Online Estimation
Authors: Wu Hai Fei , Zhao Tong
Published: October 2011

Online estimation of instantaneous frequencies is a method to treat information signals by following a set of certain algorithm for the purpose of extracting the sine wave signal frequency that is overwhelmed in the noise. Among several algorithms available nowadays, two are selected here-one is the modification of Rife (MRife) algorithm based on frequency-domain analysis; and the other is the correlation series based (CSB) algorithm. With simulation methods, the estimation error, stabilization time and computation load of these two algorithms are analyzed and compared respectively. Finally, these two algorithms are applied to estimate the vibration signal frequency of the diesel engine’s base under normal operating conditions. From the results, we come to the conclusion that MRife algorithm and CSB algorithm both have their specific advantages, whereas MRife algorithm is more applicable in the view of estimation error.
Analysis and Sensitivity Evaluation of AE Signals and Vibration Signals for Fault Diagnosis of Low-Speed Rotating Machinery
Authors: Jiang Hai Yang , Chen Peng
Published: October 2011

The fault detection of low-speed rotating machine is very difficult at the early stage. Because it often breaks down suddenly, there are many problems in the planned maintenance of low-speed rotating machinery in industry plants. In order to detect fault of low-speed rotating machinery as earlier as possible, this paper proposes a sensitivity evaluation method of fault diagnosis by using symptom parameters and frequency analysis of vibration signal and acoustic emission (AE) signal measured for the diagnosis. The practical examples are shown for explaining the efficiency of the sensitivity evaluation method proposed in this paper.
A Study of Processing of the Leakage Signal for Single Antenna LFMCW Radar Altimeter
Authors: Zeng Guo Qi , Zhang Feng , Wei Zhi Mian
Published: October 2011

To fulfill the practical demands of airborne equipment’s miniaturization and integration, topic around single antenna radar altimeter become one hot topic. But the problem of leakage signal greatly limits its applied scope. To solve this problem, first，carry out qualitative analysis on the leakage single of the single antenna altimeter; secondly, apply the Reflected Power Canceller (RPC) to the receiver of the single antenna altimeter system, and then propose the optimal design; afterwards, implement the theoretical analysis of leakage signal and the echo signal of the altimeter; finally, simulation of the cancellation performance is carried out, and the results indicate that the effect on cancelling is significant.
Nonlinear Analysis of Transmission Tower Structure by Three FEM Models
Authors: Yi Wei , Liu Xiao Hu
Published: October 2011

In this paper, three kinds of FEM models, i.e., the truss element model, the beam element model and the mixed beam-solid element model are utilized to simulate the full-scale field test of transmission tower. Based on Abaqus software, the geometric and material nonlinearity of the structure is considered. Comparing the numerical results with test data, it is found that the truss element model is no longer suitable and the mixed beam-solid element model is more accurate than the beam element model. Thus, using solid element to discrete the key nodes of the tower can greatly enhance the accuracy and reliability of the numerical prediction.
Research of De-Couple Control System for near Space Vehicle with High Maneuver and Couple
Authors: Ni Shao Bo , Hu Wei Jun , Xiong Song
Published: October 2011

A de-couple control method with information feedback from other control channel and a method with double control loops were present for the hypersonic vehicle with non-linear, couple and lateral maneuver. The whole controller was divided into two parts: the computation of actuator which deal with control couple and design of control law which solve the problem of movement and aerodynamic couple. The time-varying controller parameter method and robust control law were present to solve the problem of quick time-varying model parameter and non-linear. Finally these two methods were analyzed contrastively; the simulation result show that these two methods present above can achieve the quick dynamic and high precise track of command. But the latter was better.
Selection of Optimal Measure Project for Automatic Test System
Authors: Zu Xian Feng , Han Yu Qin , Liu Gong
Published: October 2011

An optimal solution of multi-objective optimization has been proposed for the measure project of automatic test system (ATS) because of the formation complexity and the factors diversity. The method is used to select the optimal measure project for ATS. First a quasi-ideal solution is defined using maximum subjection principle from fuzzy theory. Then calculate the subjection of the existing projects and get their maximum subjection under specific weight set. Finally the optimal measure project has been obtained. The signal integrity, data throughput, cost, degree of automation, volume scale and expansion capabilities are regarded as integrated key factors according to bus forms and system architecture. The optimal measure project of ATS is determined by finding maximum subjection. Therefore the selection method enhances the cost-effectiveness of ATS formation.
Study of Transmittance of CdS Thin Films Prepared by Spray Pyrolysis
Authors: Wu Guang Ming , Zhang Zhi Qian , Zhu Yan Ying , Cao Yang , Zhou Yang , Xing Guang Jian
Published: October 2011

Cadmium chloride and thiourea were used as raw materials to synthesize precursor solution, and CdS thin films were prepared on glass substrates by the home-made spray pyrolysis thin-film preparation device.Affects of preparation parameters, for example, the substrate temperature and fog particle velocity on the structure of CdS thin films were emphatically studied in the paper. The results showed that the optimum conditions for preparation of CdS thin films are as follows: the substrate temperature 350 °C, the gas flow rate 4L/min, and the annealing temperature 400 °C. Under the optimum conditions and argon as the carrier gas, with a spray time of 32s, a 1.9μm thickness CdS film which had a (002) plane grain size of 32.3nm was obtained. And the transmittance of the film was above 70% at the wavelength range of from 500nm to 850nm.
Preparation of High Compression Strength Silicon Hybrid Material at Low Temperature through Sol-Gel
Authors: Cui Peng , Zhang Zhao Qiang , Dou Yan
Published: October 2011

In this work, high compression strength silicon hybrid material was prepared through a sol-gel process. Structure of high compression strength hybrid material was characterized through FTIR spectra. The molar ratios of MTES to TEOS, mass ratio of siloxane to modified silicate sand were optimized to enhance compression strength. The results showed that linear Si-O-Si network and fourfold siloxane rings were produced in the sol-gel process which were necessary to obtain high compression strength material. When the volume ratio of MTES to TEOS was 3.0 and mass ratio of siloxane to sand was in the range of 0.64~0.70, the hybrid material showed high compression strength of 5.49 MPa.
Diagnosis and Prediction for Equipment Efficiency Based on OEE in FCC M6 Welding Workshop
Authors: Ma Yan Hua , Zheng Yu Bin , Zhang Yu , Jiang Ying , Zhao Li Li
Published: October 2011

Combined with the present situation of equipment management in FCC M6 welding workshop, calculate the overall equipment efficiency for welding workshop in year of 2010 and deep analysis based on this calculation, scientific prediction for overall equipment efficiency in year of 2011 at this workshop according to the method of exponential smoothing, the result indicate that tangible benefits will be got by this enterprise.
Modal and Transient Response Analysis for Complex Gear-Bearing System
Authors: Ge Jian Li , Yang Guo Lai , Hao Jian Wei
Published: October 2011

The radar antenna pedestal is a complex gear-bearing system including three rotary motions, i.e. horizontal rolling, pitching rotation and azimuth rotation. In this paper, spring-dashpot elements and connection elements are applied to simulate gear meshing and bearing connection respectively. Moreover, the equivalent average stiffness and damping of teeth meshing and bearing connection are calculated. Then, quadrilateral shell elements, hexahedral elements, wedgy elements, connection elements and spring-dashpot elements are employed to build the finite element (FE) model of the gear-bearing system in Hypermesh software. Via intermediate file, the model is imported into ABAQUS software for modal analysis whose solutions agree well with experimental data. Then, impact acceleration is imposed on the three bolts of the underpan along the x-axis, y-axis and z-axis respectively. Dynamic stress distribution and regulation changing with time under impact load are obtained. From the numerical solutions, the regions where stress and deformation is lager are found. The method can provide significant reference to analysis and optimum design of the similar system.
Research on Stator Winding Inter Turn Short-Circuit Faults of Aeronautical Fault-Tolerant Machine Based on Maxwell 2D
Authors: Zhang Ming , Zhang Yi Ming , Tong Jiang Tao
Published: October 2011

Stator winding inter turn short-circuit fault is one of the most common internal faults of fault-tolerant machine, which can disconnect the fault phases and keep operating correctly in the event of a failure. Stator winding short-circuit fault model is established through analysis. Based on finite element method, the high-power density fault-tolerant machine internal magnetic field simulation and analysis is implemented using Maxwell2D and induced voltage frequency spectrum is analyzed by FFT method. The characteristics of stator winding short-circuit faults are summarized, which lay a solid foundation for fault-tolerant machine earlier faults prediction and winding switching.
Analysis and Calculation of the Allowed Values of Contact Pressure in the Process of Circuit Breaker Closing Work
Authors: Ye Xin Quan , He Tao
Published: October 2011

Based on the analysis of forces on the circuit breaker operator and its component in any instant position during the slow closing work process, this essay applies Friction Circle Theory, Disconnecting Pairs Method and Balance Conditions of Shared Surface Power System and calculates the allowed values of contact pressure in any instant position. This essay also reaches a conclusion that in any instant position in the process of operating device slow closing work, the real value of contact pressures should be less than the allowed value of contact pressure on this position to guarantee that the slow closing work process of the circuit breaker operator is qualified.
Research on Initial Allocation and Fairness of Carbon Trading
Authors: Tang Jian Rong , Gao Xu Dong , Wu Xiao Fang
Published: October 2011

Carbon emission permit trading is widely considered an effective means to achieve optimal distribution of regional environment. The initial allocation of carbon emissions is the bases of the successful implementation of industry carbon trading. Developing low carbon economy and achieving the state’s energy saving targets are effective ways to the adjustment of economic structure, the improvement of energy efficiency and the development of new industries. The initial allocation of carbon emissions trading has a significant impact on the carbon emissions trading policy. The paper provides a theoretical basis for the choice of the allocation methods of carbon emission permit trading through the research on the fairness of carbon emission trading.
Preparation of Submicron Electrode for Electrochemical Micromachining by Multi-Step Electrochemical Etching
Authors: Liu Yong , Zhu Lin Sen
Published: October 2011

Electrochemical etching is an appropriate method for fabricating micro electrodes. We present a simple, fast, and cost-effective process for producing submicron electrode using multi-step electrochemical etching. In the study, we describe the single-step and multi-step electrochemical etching processes, respectively. In the single-step process, with machining time increasing, the intersection between micro electrode and electrolyte level will corrode off first, which could terminate the etching process. So, on the basis of the single-step process, we experimentally discussed the multi-step electrochemical etching process for the submicron electrode fabrication. Finally, the submicron electrodes were used in the electrochemical micromachining.
Wind Energy Resource Assessment for Wind Farm
Authors: Ma Hui Qun , Wang Qi Feng
Published: October 2011

In feasible research of wind farm construction, wind resources assessment is an important process. The grade of wind resources is the crucial qualification in the construction. It determines whether this wind farm is profitable or not. his paper introduces the theory of wind energy resource assessment firstly, including: wind power density, wind speed correction and Weibull distribution. Then take Yishui wind farm as example to calculate the wind energy resource assessment.
Nonlinear Spectral Subtraction Method for Elimination of Aircraft Engine’s Noise from Degraded Speech Signals
Authors: Zhao Xiu Ying , Wang Hong Yu , Tong Shou Yu , Fu De You , Zhou Hai Shen
Published: October 2011

The spectral subtraction is one of the best methods for elimination of approximate cyclical engine’s noise from degraded speech signal. Here we turn to research about the nonlinear spectral subtraction method and its improved model. After studying the nonlinear method we turn to this method that whether it can improve the quality of enhanced speech signal, propose the short-time spectral subtraction, which needs two inputs. The main input is containing the voice that is corrupted by noise. The other input (noise reference input) contains noise related in some way to that of the main input (background noise). Then use the main input’s frequency spectrum subtract the other input’s frequency spectrum. The results of experiment have proved it’s effective.
Electromagnetic Properties of Ca-Substituted Magnetic-Dielectric Composites
Authors: Zhong Hui , Wang Hua Lei , Yang Jie , Shi Yu
Published: October 2011

Ca-substituted magnetic-dielectric composites were prepared by the conventional solid-state method. XRD and SEM techniques are employed to investigate the phase composition and microstructure of ferrite particles. The complex permeability, capacity and impedance were measured with HP4291B and 4572A instruments, respectively, in the frequency rage from 1MHz to 1.8GHz. The results showed that a improvement of resistivity and Q factor occurs with the increasing content of CaCO3. The average grain size and dielectric loss decrease with increasing Ca-additions. It also found CaCO3 can promote the sintering process.
Study on Electric Field Characteristics of Converter Transformer on Valve Side Winding
Authors: Gao You Hua , Liu Guo Wei , Li Yan Bin , Gao You Feng
Published: October 2011

Numerical calculation model with compound insulation of transient electric field is given. The insulation is more prominent due to complication for voltage applied on valve side winding of the converter transformer. So the simplied structure for electric calculation on the valve side winding of the converter transformer is established. The electric field distribution characteristics on the valve side winding of the converter transformer is analyzed and electric fields in different resistivity and permittivity are calculated under AC high voltage, DC high voltage, AC superimposed DC voltage, polarity reversal voltage. The maximum electric field intensity is calculated and analyzed under kinds of high voltage. Some important influence factors for electric field distribution are also discussed in this paper.
Study on SASS with Magneto-Rheological Fluid Damper Based on Improved Variable Universe Fuzzy Control
Authors: Xia Guang , Chen Wu Wei , Tang Xi Wen , Wang Qi Ming
Published: October 2011

Considering the non-linear property of the magneto-rheological damper and the low accuracy of the traditional fuzzy control, this paper introduces a semi-active magneto-rheological damper controller which is based on the improved variable universe fuzzy control strategy and conducts a simulation of it. Next, it analyzes the damping effect of the passive suspension and the semi-active suspension. As indicated by the results, the use of the advanced variable universe fuzzy control strategy can effectively improve the ride and comfort of an automobile, and it serves as a reference for the further theoretical researches and sample vehicle experiments in the future.
Electronic Structure and Magnetic Properties of Ga-Doped Heusler Alloy Co2FeSi
Authors: Feng Yu , Wu Bo , Yuan Hong Kuan , Chen Hong
Published: October 2011

Using GGA+U (UCo=2.1eV, UFe=2.5eV) scheme based on the density functional theory (DFT), we investigate the electronic structure, magnetism and half-metallic stability of Ga-doped Heusler compound Co2FeSi. We find that the lattice constants and total magnetic moments in per unit respectively obey the Vegard’s rule and the Slater-Pauling rule well. The most stable half-metallicity occurs at doping concentration x=0.5 due to the Fermi level is situated slightly above the middle of the spin-down gap. Our studies also indicate that the RKKY-type exchange mechanism plays a dominating role in determining the magnetism of HMFs.
Ferromagnetism and Electronic Structure in Nitrogen-Doped ZnO Nanowire: First-Principle Calculation
Authors: Liao Yu Qiao , Yuan Hong Kuan , Kuang An Long , Wu Bo , Feng Yu , Liu Zhong Lin , Chen Hong
Published: October 2011

The nitrogen dopants can convert the nonmagnetic ZnO into a ferromagnet based on first-principle calculations. The formation of oxygen substituted with nitrogen on the surface is much easier than that inside nanowire. Calculation results indicate per N dopant can produce a total moment of 1.00 uBin the nitrogen-doped ZnO, the magnetic moments mainly come from the unpaired 2porbit split of N atom. Our theoretical study not only demonstrates the ZnO nanowire can be magnetic even without transition-metal doping, but also suggests that introducing N dopant is an effective way to fabricate low-dimensional magnetic ZnO nanostrucres.
Synthesis and Humidity Controlling Behaviors of Sepiolite/Poly (Sodium Acrylate-Acrylamide) Composite
Authors: Wang Ji Hui , Dong Fei , Ren Shu Ping
Published: October 2011

Sepiolite/poly (sodium acrylate-acrylamide) composite was synthesized by using inverse suspending polymerization method under different dispersant content, neutralization degree and ratio of monomer with orthogonal experiments. The surface morphology, structure and humidity controlling properties of composite were observed and determined. The results show that sepiolite/ poly (sodium acrylate-acrylamide) composite is in a fine particle with rough surface. During the polymerization process, acrylate and acrylamide monomer is grafted with hydroxyl on the surface of sepiolite and then intercalated successfully into the silica layers of sepiolite. The impact of three factors on the humidity controlling behavior of composites increases by the order of dispersant content, ratio of monomer and neutralization degree. The optimum preparation parameters are dispersant content of 10%, neutralization degree of 85% and ratio of monomer 2:1.
Gelator In Situ Modify PMMA
Authors: Chen Si , Xu Jian Ming , Tang Guo Dong , Wang Xu
Published: October 2011

Gelator (G2-C12-G2) was synthesized successfully, the structure of which was confirmed by1H-NMR and Mass spectra (MS). And G2-C12-G2was used to modify PMMA by “in-situ” polymerization. The results of gel permeation chromatography (GPC) showed that Mn and Mw/Mnof the PMMA composite were barely influenced by the incorporation of gel. The results of dynamic mechanical analysis (DMA) showed that the modified PMMA had higher modulus, toughness and glass transition temperature (Tg) than pure PMMA. Furthermore the results of spectrophotometer showed that the transparency of modified PMMA was nearly the same as pure PMMA .