bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Electrode Coatings on Diffusible Hydrogen Content, Hardness and Microstructures of the Ferritic Heat Affected Zones in Bimetallic Welds
Authors: Bhandari Deepak , Chhibber Rahul , Arora Navneet
Published: November 2011

Bimetallic welds (BMWs) have been a necessity within the steam generators of nuclear power plants, where the heavy section low alloy steel components are usually connected to stainless steel primary piping systems. These welds represent zones with metallurgical discontinuities, which tend to localize the strains and cause failures. The other critical issues which must be taken care of while welding of bimetallic joints include solidification cracking, thermal fatigue and residual stresses in welds. The occurrence and severity of all these problems associated with bimetallic welds depend upon the type of welding process used along with the other variables like welding consumables, heat input etc. In shielded metal arc welding (SMAW), welding electrode consumables/coatings play an important role in deciding the weld metal quality. The development of welding electrode coatings is quite difficult due to very rapid complex reactions taking place during welding and the involvement of many controlled process variables. The present paper is an effort to highlight the general issues and challenges for the systematic and scientific development of welding electrode coatings for bimetallic welds. The experimental procedure contains three sets of coated electrodes having varying ferro-alloys, silica and carbon content. In the first set of electrodes, non-ferrous elements are also introduced into the weld metal through flux addition. Further, the welded joints are subjected to various tests and then evaluated to ascertain their mechanical as well as metallurgical behaviour.
Modeling and Simulation of a Vehicle Equipped with Power Split Automatic Transmission
Authors: Zhang Qing Yong
Published: November 2011

his paper is concerned with the fuel economy of a mini car with power split automatic transmission (PSAT) by means of simulation. Firstly, a PSAT prototype is developed featured with high efficiency by power split. Secondly, mathematic models of PSAT, based on the PSAT scheme and experiment on the prototype, is established and embedded into the simulation software NREL’s Advanced Vehicle Simulator (ADVISOR) to carry out the whole vehicle fuel economy simulation. Thirdly, fuel economy comparison between vehicle with PSAT and traditional mechanical transmission is present, after fuel economy simulation under different driving cycle. Finally, approach to the energy save scheme of PSAT and matching between PSAT and the whole vehicle is discussed which builds up a good foundation for future optimization on control strategy of PSAT.
Reactive Power Optimization Based on Improved Particle Swarm Optimization Algorithm Considering Voltage Quality
Authors: Zhu Ying Ping , Cai Ze Xiang , Zhang Yong Jun , Song Yong Chao , Yang Yin Guo
Published: November 2011

With the target of voltage quality, an improved PSO algorithm is proposed in reactive power optimization(RPO) of power system. The algorithm adopts some way of chaos theory and flexible inertia weight based on basic PSO and suitable penalty factor on function constraint, which can overcome limitations of partial constringency in basic PSO and improve the efficiency in global optimizing. The simulation of IEEE-14-buse shows this algorithm has better convergence than basic PSO algorithm.
Thermal Analysis and Test for a High Speed PM Machine for Fan Application
Authors: Wang Ji Qiang , Wang Feng Xiang
Published: November 2011

For a give air flux, the higher speed the fanner is running, the smaller the fanner’s size is. It is also well known that for a given power, the higher the machine’s running speed, the smaller the machine’s size has. If the fanner is geared to a high speed machine directly, the fan set’s volume will be sharply decreased. However, the heat dissipation of the high speed machine becomes a serious problem also due to the small size and high power loss density. Therefore, how to estimate accurately the power losses and temperature rise is a key issue for the high speed machine design. In this paper, the power losses and temperature of high speed PM machine for a fanner application are thoroughly investigated. And the test results of a prototype fan set partly shown the validity of the calculation method.
A Load Shedding Scheme for Long Term Voltage Stability Enhancement by Multi-Stage Model Predictive Control
Authors: He Yu , Zhang Jing , Peng Zhi Wei , Dong Zhao Yang
Published: November 2011

Power system load shedding has been used as an emergency control method to prevent possible power system instability problems. In this paper, a new multi-stage model predictive control based load shedding scheme is proposed to enhance long term voltage stability of a power system. The main advantage of this new method is the capability of the scheme to handle multi-stage control actions, which may also be disturbances to a power system at a critical status toward instability. A new cost function is defined for the model predictive control scheme. The proposed scheme is tested on the New England 39-bus system to validate its efficiency and effectiveness in preventing system long term voltage stability problems.
Analysis and Optimization Design of Self Magnetic-Suspension Permanent Magnet Linear Synchronous Motor
Authors: Zhang Wu , Lan Yi Peng , Zhang Feng Ge
Published: November 2011

In order to eliminate the friction force of linear motor nc machine tool feed system and improve the machining precision, a new Self Magnetic-Suspension Permanent Magnet Linear Synchronous Motor(PMLSM)is putted forward in this paper, which can generate the suspending power by itself. In this paper, the magnetic field distribution is calculated by means of equivalent magnetizing current and Schwarz-christoffel transformation, and is further analyzed and verified by using Finite Element Method. Furthermore, the method of optimizating the length of the primary iron-cored is adopted to design the motor. The experimental results shows that self magnetic suspension -PMLSM can generate thrust and suspending force separately, and the thrust and suspending force are improved by applying optimized method.
Vehicle Model Recognition Based on Fuzzy Pattern Recognition Method
Authors: Wang Yi Qiang , Huang Rui Jian , Xu Tian Yi , Tang Ke Hong
Published: November 2011

The method based on the theory of Fuzzy Pattern Recognition is divided into three parts. Firstly, use Hough transformation to extract the feature points of vehicles, and use the ratio between two absolute distance of adjacent feature points as the characteristic values of vehicles; secondly, use Fuzzy C-mean Classification to handle feature data of 75 car model, then establish a degree of membership matrix as the sample space; thirdly, consider the classification algorithm based on fuzzy approach degree and the credibility of the vehicle feature to propose a weighted close- degree recognition algorithm. This recognition method has a good effect.
Structure and Finite Element Analysis for a Permanent Magnet Bias Axial Magnetic Bearing
Authors: Zhao Xu Sheng , Deng Zhi Quan , Wang Bo , Hua Chun
Published: November 2011

A new permanent magnet bias axial magnetic bearing (PMAB) is introduced, then the structure and operation principle are analyzed. The equivalent magnetic circuit is established to deduce the mathematic expression. The parameter design and calculation of the magnetic bearing are presented including available area of magnetic pole, ampere - turns of control coils etc. The parameters of the proposed prototype are also given. The 3-D magnetic field simulation is performed by using the Finite Element software. The theory analysis and the simulation show that the maximum suspension magnetic force satisfies the design requirement. The magnetic suspension forces have better linearity and symmetry around the balanced position. Therefore, the proposed PMAB is suitable for the high speed or low loss occasions.
Study on Dynamical Modeling of the Rolling Mill Vertical System
Authors: Shi Xian Jin , Wu Di Ping , Gao Zhi Ying
Published: November 2011

Vertical vibration is universal in the vertical system of rolling mill. It has a seriously bad effect on the quality of strip. Dynamic model of the vertical system plays an important role in the analysis of vertical vibration in rolling mill. On the basis of 1420mm six roller cold rolling mill, ADAMS rigid model and flexibility model are established in this paper. Contact stiffness of rollers is calculated through ansys simulation. Contact stiffness between the work-roll and strip is calculated by using theoretical methods and stiffness of mill stand is calculated by simplifying mill stand structure. Natural frequency and some amplitude-frequency response of vertical vibration are analyzed. The test results prove that the modeling method is feasible. Vibration derived from the deformation of rolls can be observed directly in the flexible model, which can’t be realized in the rigid body model. At the same time, the new method of calculating vertical system stiffness is also proved to be reasonable.
Design of Bending Fatigue Machine for Flexible Electronics
Authors: Cao Hu Wen , Yang Ping , Bao Bi Zhen
Published: November 2011

According to the current requirements of bending fatigue test for flexible electronics, a bending fatigue machine based on SCM (single chip Microcomputer) has been designed. using stepper motor driving screw nut body as loading mechanism, improve the accuracy of the structure effectively by gaps eliminator, and achieve the requirement of precision control by using fraction driving technology in the motor control. Photoelectric counter and electrical signals detection circuit have also been designed to achieve unattended function. This design plays an important role in the following testing process.
The Theoretical Study and Error Analysis about On-Site Calibrating Technology of Low-Voltage Metering Device Composition Error
Authors: Xiao Hai Hong , Chen Tao
Published: November 2011

The paper mainly discusses how to calculate composition error of low-voltage metering device. The composition error of metering device, the error of power meter and the ratio error of CT were calculated also by comparing the standard power meter with the calibrated power meter .The formula of error calculation was put forward, that will has an important guiding significance for the development of on-site calibrating instrument
Torque Ripple Reduction of Brushless DC Servo Motor Using Full EMF Feedback
Authors: Xia Jia Kuan , Yuan Ye , Huang Wei
Published: November 2011

Torque ripple reduction of the brushless DC motor has been the main issue of the servo drives in which the speed fluctuation and the vibration should be minimized. Un-ideal back EMF (electromagnetic force) usually induces distinct torque ripple. A full EMF feedback strategy is presented in order to effectively reduce torque ripple. The relationship between the terminal voltage of auxiliary winding and the back EMF of brushless DC motor are investigated, and the back EMF can be measured on-line by using the auxiliary winding, the q-axis current for a constant torque to produce is calculated through coordinate transformation when d-axis current is zero, and the reference q-axis current is adjusted in real time by vector control in dq0 coordinate. The simulation results show that the proposed strategy can effectively minimize the torque ripple.
A Technology of Composite Real-Time Image Processing of Profile Measurement
Authors: Li Tian Ze , Hu Ke Ping , Hou Luan , Jiang Chuan , Lu Heng Wei , Zhang Xia
Published: November 2011

This paper, innovative approaches are based on laser scanning and image analysis, presents an efficient composite technique for object profile extraction with real-time image processing. High throughput is obtained by algorithmic prefiltering to restrict the image area, while high accuracy is achieved by neural recontruction of the profile.
Applied Research on the Electric Wet Effect in Optical System Design
Authors: Huang Zhi Qin , Quan Pei Ying , Zhang Jin Li
Published: November 2011

In the past half century, the camera industry has developed very rapidly, which drove the optical lens and optical zoom technology to make great progress. The zoom lens’ technology principle of current mainstream optical zoom lens system is achieved by adjusting the relative position of the lens, objects and the focus. This paper takes the double-liquid zoom lens based on electric wet effect as the basis , the new zoom optical system is designed to achieve motor control without mechanical movement, then the vision correction is designed by using liquid lens, such as the correction of myopia and hyperopia, which can automatically identify the eyes degrees of myopia and hyperopia, avoid frequent replacement lens steps when optometry is done for eyes.
Influence of Pulsed Power Equipment’s Driving Manners on Launching Process of the Electromagnetic Coil
Authors: Sun Peng , Lei Bin , Li Zhi Yuan , Zhao Ke Yi , Guo Chun Long
Published: November 2011

For improving launching velocity and efficiency of intercepting plate in active electromagnetic armor protective system, theoretically analyzing the main parameters that determine the change of electromagnetic force. Investigating the system dynamic changes in different pulsed power equipment driving manners. Combining different driving manners, the dynamic working process of the intercepting plate launcher are simulated, that adopting finite element analytic software Ansoft’s transient solution to simulate the dynamic process of intercepting plate. The maximum velocities obtained in the bipolar driving manner and in the single-polar driving manner are 12.61 m/s and 14.00 m/s respectively. Analysis shows that the effect of the electromagnetic force is not only related with the driving manners but also with the materials.
Online Calculation Method of Boiler Efficiency by Oxygen Measured at a Wet Basis
Authors: Zhao Zhen Ning , Ge Ya Qin , Zhu Xian Ran , Liu Cheng Yong , Zhang Qing Feng , Zhao Zhen Zhou
Published: November 2011

Currently, the most widely used method to calculate boiler efficiency is based on wet basis oxygen which is measured by online instrument, rather than on dry oxygen. Consequently, it often results in the deviation of calculation results, as well as bad adaptability to different kinds of coal. In this study, an online calculation method of boiler efficiency as deducted based on the wet oxygen, and validated by typical soft coal and lignite. It is revealed that the results of this calculation model is more close to that of standard calculation method by elementary analysis. Moreover, the online calculation method can exhibit a better performance of coal adaption, which can be used as a method to guide for the better optimization of utility boiler combustion.
Study on Automatic Test of the High-Precision I/F Converter
Authors: Dong Ming Jie , Wang Bo , Gao Zhi Feng
Published: November 2011

A new method that uses the same clock signal between the frequency test system and the I/F converter is provided to avoid the frequency test error. The standard instruments such as FLUKE 5520A calibration and FLUKE 8508A 8½precision multimeter are used, that not only simplifies the design of the test system but also enhance reliability of the system. The RS232 bus and the GPIB bus are used to achieve the automatic test.
Research on Online Monitoring of Gear Fault of Wind Power Gearbox Based on Undecimated Wavelet Transformation
Authors: Zhou Fu Cheng
Published: November 2011

According to fault characteristics of wind turbine gearbox, an On-line Monitoring System of wind turbine gearbox based on the undecimated discrete wavelet transformation was developed. Measured the vibration signal of gear fault in the laboratory, The signal after undecimated wavelet transformation can be more accurate and clear display characteristics, which was conducive to diagnose gear failure quickly and effectively.
High-Accuracy Fundamental Frequency Detection in Power System
Authors: Li Ling , Jin Guo Bin , Huang Shao Ping , Peng Xiao
Published: November 2011

A novel method on frequency measurement based on improved TLS-ESPRIT (total least square estimation of signal parameters via rotational invariance techniques) is proposed in this paper with the research on fundamental frequency measurement in power system. TLS-ESPRIT is belong to subspace estimation in modern signal process. Noise is included in signal model, so it is independent on noise. But the same multi-poles cannot be taken when signal is in noise and based on TLS-ESPRIT. Multiple poles restoring is presented to take the true poles accurately. It is revealed that fundamental frequency is detected accurately in harmonics, interharmonics, noise and frequency fluctuations and better anti-noise ability in particular better adaptiveness on time varying signal in amplitude by simulation results.
The Design of Microwave Cavity Resonator Used for Measuring the Moisture Content in Plant Leaves
Authors: Liu Jiu Qing , Feng Rui , Wang Wei
Published: November 2011

This paper designs the cavity parameters of rectangular microwave cavity resonator, mainly including the design of cavity size, coupled diaphragm radius, and the position to place leaf, to make the largest power of resonant cavity and most significant impact on S11 parameters when the dielectric constant changes. Then conducts optimized analysis with finite element analysis software HFSS, gains the relation between dielectric constant and resonator parameters within the 3.2GHz-3.8GHz swept frequency range, and analyzes the simulation results. Finally, concludes the application sphere of cavity resonator designed in this paper according to the multiformity of plant leaves measured, and makes a simple introduction to the improvement methods.
Software Development and Data Processing of Tool Wear Based on Mapping Measurement
Authors: Guo Song , Zhang Chen , Liu Xi Hui
Published: November 2011

In NC milling process, tool wear has great influence on the machining quality of product. In this paper, a mapping measurement method is used to obtain tool wear and a data processing method is proposed to deal with the data getting from the measurement. First, tool wear along radius of tool’s cross-section, which is called radial wear, can be obtained by mapping measurement method. Then tool flank wear can be easily calculated based on the established relationship between radial wear and flank wear. In order to get radial wear, we process those measured data that are obtained from mapping measurement. In this process, least square method is adopted to fit these data to get the radius of section circle at a certain position. So the radial wear can be obtained by comparing the radius of the fitting circle and the original radius of tool at a certain section. Finally, the data processing software is realized by using Visual C++ development tool according to the designed data processing method of tool wear.
Integration of Neural Network and Symbolic Inference and its Application to Detection of Foundation Piles
Authors: Yang Zhong , Si Hai Fei
Published: November 2011

An integrated system for neural network and symbolic inference is presented. In the system the two intelligent functions, neural network and symbolic inference, can work together to make greater contributions. By applying it to the computer simulation for detection of foundation piles, the system is proved to be effective.
A Traffic Flow Detection Algorithm in the Intersection Electronic Police System Based on Video
Authors: Yang Miao , Liu Rui Ming , Liu Qiang , Zhang Hong Yuan
Published: November 2011

The Electronic Police System is an important trend of the development of the Intelligent Traffic System present. Aim at video images taken by the Electronic Police System, a kind of vehicle detection algorithm based on detecting area is proposed. This method combines background difference with edge difference and morphological steps to detect vehicles, and the accuracy of the algorithm is further improved by correcting the frame data stream. Experimental results demonstrate that the algorithm is effective and can meet the needs of real-time requirement.
Temperature and Humidity Measurement System for Grain Storage Based on nRF905
Authors: Yang Shu Lian , Shen Jin , Li Zhen Mei , Tan Bo Xue , Zhao Kai
Published: November 2011

A temperature and humidity measurement system for grain storage is developed. In the system, digital temperature and humidity sensors and single chip UHF transceiver were used. The system consists of the host controller used to manage extension device in each granary and the data transmission, and extension devices fixed in each granary were used to periodically measure temperature and humidity and transmit temperature and humidity data following instructions from host controller. Besides the advantage of simple structure, being easy to maintain and good measuring stability, the system characterized by wireless transmission of temperature and humidity sample data, which make it suitable for spread around grain storage.
The Short-Term Load Forecasting Based on Rough Set
Authors: Pi Zhi Xian , Xu Ru Zhi , Guo Jian
Published: November 2011

Short-term load forecasting in power system is an important daily work in Dispatch Operation Department of Power System. The level of forecasting accuracy directly affects the operating economy and supply quality of power system.This paper adopts the rough sets to forecast short-term load. It designs an overall structure of forecasting the short-term load based on the rough sets, applies the rough sets to analyze the importance of attribute of each condition on decision-making attribute and then gets a reduced forecasting system, lists examples to forecast short-term load on the basis of the real historical data, and compare the results with the traditional decision-making tree algorithm. The results of this study prove that the rough sets is much practical in short-term load forecasting.
Measurement and Analysis on Power Quality of Electric Railway Traction Substation Based on LabVIEW
Authors: Hu Yang Yu , Fu Hong Jun , Wu Jun Yong , Ji Lu Yu , Zhang Xi Lu
Published: November 2011

A general power quality measuring system based on virtual instrument (LabVIEW) has been developed. For two electric railway traction transformers of Zhengzhou-Xi’an High Speed Passenger Dedicated Line, which access to Zhengzhou, Henan Grid, some important power quality parameters have been measured and analyzed. Then, the analysis results are compared with the calculation results by Power System Harmonic Penetration Software (PSHP), which is developed by our group. It shows that real measured data of Harmonic Ratio and Three-phase Unbalanced Factor of electric railway traction substations is comparable well with the calculation results. Furthermore, Three-phase Current Unbalanced Factor accorded well with the theoretical value of the V/v-connected traction transformer, and Total Voltage Harmonic Distortion and Unbalanced Factor meet the requirements of relative national standard.
Development of a Capacitive Displacement Sensor Based Portable Instrument with Digital Display for Measuring Weld Stagger Joint
Authors: Ma Xiu Shui , Ma Xie , Qian Xiao Chao
Published: November 2011

In order to ensure the operating security of pressure containers, the P. R. China make a corresponding standard of producing, checking and accepting pressure containers, in which the weld stagger joint is an importance parameter to be measured. Because the zero scale is fixed, the existing mechanical stagger joint measuring scale has scoring error of scale, zero error, visual error and cumulative error, it is not convenient to read and easy to get wrong data, resulting in misjudgment and other defects. The existing capacitive displacement sensor based instrument with digital display for measuring welded joint angularity and stagger is the parameter detection after the weld completed, it cannot be used for detecting welded joint stagger joint before welding, so it is not convenient to adjust the weld and control the welding quality. To make up for the lack of existing measurement tools, we developed a capacitive displacement sensor based portable instrument with digital display for measuring weld stagger joint. This paper introduces its structures and principle. Through error analysis, calculation and experimental testing, the integrated error of the instrument is less than 0.03 mm, the measuring accuracy can meet the requirements prescribed by the GB150-1998 standard.
Asynchronous Motor Bearing Fault Detection Methods
Authors: Sun Li Ling , Zhang Bao Long
Published: November 2011

Bearing, asynchronous deep groove ball bearings are widely used in induction motor field. Motor bearing failure probability is as high as 40% in asynchronous motor. It accounts for the largest proportion of failures in the motor. Therefore, people have been on studying motor bearing fault detection methods for further research. So far, people have studied a variety of modern detection methods.
Actual Motion of 3-DOF Parallel Robot
Authors: Tian Dong Xing , Han Shu Kui
Published: November 2011

The Lower DOF parallel robot rely on strictly geometrical constraints of axis of pairs in and between limbs to obtain the reduced number of DOF .In practice ,these constraints will never been perfectly fulfilled due to the inevitability of errors, and hence produce series bad effects and problems. Using screw theory and set theory as mathematical tools, the DOF and constraint system of 3-CRR parallel robot, were systematically summarized and in-depth studied. Kinematics design of a limited DOF parallel robot, a 3-CRR pure translational parallel robot, is presented that takes into account the error. The errors presented in the paper consist of two kinds. The errors is defined as the position error of rotation center of the platform caused by errors in the kinematics constants, such as axis error The above research results provided an insight into the error of 3CRR parallel robot.
Influence of V/Hz Limiter on Generator in Isolated Operation
Authors: Liu Rui Lan , Liu Wei , Liu Peng , Dou Qian
Published: November 2011

The action of V/Hz limiter of generator excitation system and its influence on generator in isolated operation are analyzed with the generator in Youjiang hydro power station as an example which is in isolated operation with local load after the trip of main transformer of 500kV Baise substation in Guangxi power grid. It is pointed out that the action of V/Hz limiter is the reason that causes the long time operation of generator under low voltage and low frequency status. Suggestions on the functions of V/Hz limiter and how to avoid such low voltage and low frequency operation status are proposed.
Numerical Improvements to Closed-Loop Ascent Guidance
Authors: Pan Bin Feng , Tang Shuo
Published: November 2011

This paper presents numerical enhancements for optimal closed-loop ascent guidance through atmospheric. For 3-dimensional ascent formulation, optimal endo-atmospheric ascent trajectory is numerically obtained by the relaxation approach, and the exo-atmospheric ascent trajectory is generated by an analytical multiple-shooting method. A new root-finding method based on double dogleg method and More’s Levenberg-Marquardt method with Gaussian elimination is presented. The simulation results indicate that our new algorithm has remarkable computation and convergence performances.
Study on SRUKF Applied in Initial Alignment with Large Misalignment Angle on Stationary Base of SINS
Authors: Cheng Kai , Huang Chun Mei , Zhao Yue Yuan
Published: November 2011

The initial alignment error model of SINS (Strap-down Inertial Navigation System) with large misalignment angle is nonlinear. The traditional EKF (Extended Kalman Filter) was used to linearization a nonlinear system, but its performance is limited. In this paper we use the SRUKF (Square Root Unscented Kalman Filter) to process this nonlinear system and the results indicate that SRUKF is better than EKF in convergence speed and estimation accuracy.
Fault Monitoring of Transformer Based on FTIR
Authors: Jiang Shu Bo
Published: November 2011

Transformer is important power transmission equipment, and its working condition directly affects the safety level. Using the Fourier transformer infrared spectrometer for the qualitative analysis of the fault gases, using the theory of BP neural network for the quantitative analysis of the characteristics of the fault gases, can determine the operational status of transformer. This method monitors the function of the transformer effectively, judges the potential failure or hidden dangers accurately.
The Generation of Droplets with Micro-Liter Volume Using Surface Acoustic Wave
Authors: Zhang An Liang , Han Qin Jiang
Published: November 2011

We developed a digital micro-fluid generator for the discrete dispensing of bio-samples into a bio-analytical unit on piezoelectric substrate. This micro-fluid device is comprised of a micro-channel, a step and a 1280 yx-LiNbO3 substrate. An ejector jet pump is used for offering a uniform linear velocity. After formed micro-fluid from micro-channel arrives the step, it will be down to the piezoelectric substrate due to its gravity and will be transported by surface acoustic wave (SAW). The micro-fluid generator can generate mono-disperse digital micro-fluid of micro-liter volume relied on the gap between micro-channel and the step. The generation time of digital micro-fluid is about several seconds time, which is also relation to the gap. And the digital micro-fluid generation is repeatable and stable with a typical variation of less than 7% of digital micro-fluid volume. Our digital micro-fluid generator can be effectively applied to biochemical analysis on a piezoelectric substrate.
Low Bit Rate Speech Coding Using Lattice Vector Quantization and Time-Scale Modification
Authors: Xiao Qiang , Chen Liang , Geng Chao
Published: November 2011

This paper presents a low bit rate speech coder based on predictive lattice vector quantization (PLVQ) and time-scale modification (TSM). The coding model of proposed vocoder is built on the MELP, in which bit rate reduction is achieved by taking advantage of PLVQ and TSM techniques. PLVQ is used to encode the speech line spectrum pair (LSP) parameters, which has the advantage of lower implementation complexity than multi-stage vector quantization (MSVQ), moreover, it does not require memory for codebook storage. With our speech data base, PLVQ can save up to 4 bits/frame compared to unstructured codebook MSVQ. TSM can change the speed of speech signal with its perceptual characteristics remained. Through appending TSM as previous and post process, speech coding at bit rate about 1.1 kbps could be easily achieved without modifying the vocoder structure.
The Design of DC Motor Excitation Regulation System Based on DSP
Authors: Yang Lv , Zhao Jing Hong
Published: November 2011

The performance of excitation control system directly influences the motor’s movement characteristics. Currently, a lot of traditional excitation systems which use analog control circuits have the problem with their poor stability, aging components, slow response and great power lose. Aim to solve these problems, this text designs and implements a digital excitation regulation system based on DSP for DC motor. The regulation system takes full advantage of the powerful data processing ability of DSP chip for real-time rotational speed control of DC motor. This design is capable of ensuring the stability of the excitation system and improving the control efficiency, the circuit design is greatly simplified at the same time.
A Simulation Software of Critical Sour Well Blowout Based on FLUENT
Authors: Ma Qing Chun , Zhang Lai Bin
Published: November 2011

Well site safety plan, which included well design, emergencyresponse plan (ERP) etc, is the key prerequisite for drilling the critical sour gas well. A right emergency response zone (EPZ) is quite difficult to make sure on the site, because that it affected by release rate of H2S, gas composition, the well site surrounding topography, and other specific circumstances. To solve this problem, A blowout simulation software based on FLUENT be developed, which could predict affected areas when the critical sour blowout, the gas flow direction, and the H2S concentration distribution. On this basis, the safety layout surrounding the well site can be planned. The article provides the design structure and main functions of the software. The software can provide the theoretical basis of industrial safety.
Study on Piezoelectric CeramicType Insole Plantar Pressure Measurement System Based on Test Point
Authors: Guo Ye Min , Wang Lan Mei , Ge Yun Yan
Published: November 2011

According to the requirement of measurement of plantar pressure, this thesis puts forward a plan to construct a new insole plantar pressure system based on multifunction data acquisition modular and Test Point. Then the hardware part and software part are designed and developed respectively. The piezoelectric ceramic type sensors are designed, manufactured and calibrated according to scientific methods. Meanwhile, the DAQ card is selected carefully. Of course, the software part is developed based on Test Point. A series of tests are performed in order to validate the function of the plantar pressure measurement system. The results satisfy the anticipated design requirements. At last, the problems and application trend of the plantar pressure system are predicted.
Wavelet Analysis of Natural Annual Runoff in Dongjiang River
Authors: Li Jing , Chen Qiu Wen , Li Da Mei
Published: November 2011

To maintain the ecosystem health and guarantee the social-economic water demand in the Dongjiang river basin, proper management of the water resources is essential. This research introduced the Morlet Wavelet analyses method to investigate the patterns of the past 45 years runoff times series of the main gauges in the Dongjiang River. The general trend and the changing characteristics in both time domain and frequency domain at different scales were revealed. The results were verified by the real part of the Wavelet coefficient and the Wavelet variance. The study discovered that the runoff in the basin exhibited multi-scales of main circle, synchronization and declining. The results could provide valuable information for the management of the water resources and ecosystem of the Dongjiang River.
Fuzzy Controller Design Used for Steel Length Measurement
Authors: Hou Chong Sheng
Published: November 2011

The accurate measurement of the length of steel plate is the key to control technology for cross-cutting production line. Three steel plates determining-length control algorithms were deeply analyzed, in the set-length control strategy fuzzy control technology was introduced, and determining-length fuzzy controller structure and realization was analyzed; In order to improve the accuracy of steel plate crosscut, on the basis of the fuzzy control system self-learning function and artificial self-learning function were increased. Practical applications show that technical advancement, reliability of the control system and shear plate accuracy are high, fully meet the requirements of control.
Development of a 3D Vision Coordinates Measurement System Using Planar Target
Authors: Fu Qiang , Zhao Hong , Cao Nan , Li Jin Jun
Published: November 2011

Three-dimension vision coordinates measurement presents many virtues such as high accuracy, flexible construction, simple operation, large measuring range and high measuring speed. So it has become a hot spot of application and research in many fields such as manufacturing, reverse engineering and computer aided surgery. In this paper, a 3D vision coordinates measurement system based on binocular stereo vision and a planar target has been designed and set up. The system’s composing and measuring principles are discussed. The geometric model and detail design of the planar target, which is one of the main factors affecting the system’s measuring stability and accuracy, are presented. A new algorithm for target calibration is proposed. The location and orientation of the planar target can be reconstructed according to rigid geometric transformation. Further results of calibration and measurement are verified experimentally, and a high geometrical accuracy can be achieved.
An Instantaneous Measurement Based Transformer Protection Scheme
Authors: Gu B. , Tan J.C.
Published: November 2011

A transformer protection scheme using fault component computed from instantaneous measurement values is proposed in this paper. The algorithm utilizes reactive power directional elements computed from the received IEC 61850-9-2 sampled values, and uses the ratio of active and reactive currents to determine an inrush condition. A transformer fault is declaimed if the directional elements from all transformer terminals seen the fault in its forward direction. Extensive simulation tests show that the proposed algorithm is sensitive to detecting faults, and is able to distinguish faults internal or external to the protected transformer zone, and to discriminate a fault from inrush conditions.
The Time-Delay Study on Vehicle Active Control Suspension
Authors: Kou Fa Rong
Published: November 2011

Actuator is a key factor for vehicle active suspension. A new vehicle active suspension is put forward based on the Electro-Hydrostatic Actuator (EHA).For vehicle active suspension system, unavoidable time delay may appear in the controllable course. The critical time-delay of EHA active suspension is calculated in this paper and time-delay influence on the dynamic performance of vehicle active suspension is analyzed. A time-delay compensation strategy for EHA active suspension is proposed to reduce time delay. A self-adapting fuzzy controller is designed and applied to active suspension system with EHA. Physical prototype and experimental rig for EHA active suspension are built. Then time-delay tests of suspension prototype are carried out on the developed test rig. Test results show that the sprung mass acceleration of the active suspension with time-delay compensation significantly declines by 12.4% under the road input of 1.2Hz and by 13.6% under the road input of 1.6Hz.
Fault Position Identification for Series Compensated Lines with SSSC Based on Improved Wavelet Packet Entropy
Authors: Liu Qing , Chang Yan Yan , Xu Yan
Published: November 2011

In this paper, the correction factor is introduced to improve the wavelet packet entropy, which is used to analyze the transient fault current of the series compensated line with Static Synchronous Series Compensator (SSSC). The results show that the wavelet packet entropy when the fault point is before SSSC is much larger than that when the fault point is after SSSC. According to this characteristic, the scheme of identifying fault position for series compensated lines with SSSC is put forward. Cooperated this scheme with the distance protection, the measured impedance of distance protection is adjusted adaptively so that the over-reaching and under-reaching of the distance protection due to SSSC can be eliminated effectively.
Optimal Level Flight Trajectories of Stratospheric Airship
Authors: Qin Feng Ping , Chen Li
Published: November 2011

This paper focuses on the stratospheric airship in the level flight state, and designs a optimal method which combines the direct collocation method and sequentially quadratic programming algorithm to get the optimal trajectories. Both the minimum time and fuel are considered. The result indicates that this method is very efficient to the problem and can supply the idea to utilize the wind to save fuel and time in the actual flight.
Research on Fiber Bragg Grating Sensor Monitoring Method for Dynamical Stress of Centrifugal Blower Vane
Authors: Hu Zhi Xin , Ma Yun Bin , Huan Shuai , Zhen Yu Chun
Published: November 2011

Monitoring method for dynamical stress of centrifugal blower vane based on Fiber Bragg Grating (FBG) sensing technique is presented in this paper. Consisting of FBG sensors, FBG interrogator and fiber optic rotary joint, this monitoring system has bare FBG as strain sensor, monitors stresses at the inlet and outlet of the centrifugal blower. Details about stick up method of FBG sensors are shown in this paper, either. In addition, this method has been applied to experimental model of centrifugal blower, and it was found that: stress at the outlet of the air vane is more than that at the inlet; within the working range, stress of air vane increases in company with increment of rotating speed, though it is not linear relation between them.
Estimating the Threading Dislocation Density of Thick GaN Films
Authors: Wang Ru , Zhang Jun Ling , Yang Rui Xia , Zhang Xiu Jun
Published: November 2011

The threading dislocation density (TDD) of thick GaN films grown by hydride vapor phase epitaxy (HVPE) was estimated through counting etch pit density (EPD) and calculating full width at half maximum(FWHM)of double crystal X-Ray diffraction (DCXRD). TDD was about 108 through counting EPD, while it was about 109 through calculating the FWHMs of (0002) and (10î2). The experiment results show that the two methods are both suited to estimating the TDD of the thick HVPE-GaN films with 350um thickness. But they have some difference: EPD method is fitter in evaluating the dislocation density of the surface of thick GaN film, but FWHM method can gain the total dislocation density of thick GaN film. The method calculating the FWHMs possesses more general statistical significance.
Transient Combustion and Hydrocarbon Emission Characteristics of a Port-Fuel-Injected Engine
Authors: Zhou Jian Hao , Yuan Yin Nan , Liu Xian Qiang , Du Jia Yi
Published: November 2011

An experimental paltform for simulating the starting process of a PFI engine was set up. The contrastive analysis of prototype engine between conventional start with starting motor and high-speed cranking start with ISG (Integrate Starter/Generator) was carried out. Variation regulation of the transient engine speed, the cylinder pressure, the fuel compensation factor, the intake manifold pressure and the transient HC emission were elaborated. The results show that, with the increase of cranking speed, the intake air pressure dropped, and the intake air quantity reduced as well. The duration of fuel evaporation was shortened, so the fuel atomization was insufficient. The possibility of misfire was increased and the transient HC emission was prominent. All these phenomena had a close relationship with ECT (Engine Coolant Temperature). Fuel compensation in the first few working cycles during starting process could make the original lean mixture more preferable in order to improve the combustion environment.
Field Analysis of Ridged Waveguides USING TRANSFER MATRIX
Authors: Zong Wei Hua , Shao Ming Xin , Qu Xiao Yun
Published: November 2011

The mode matching method is applied to analyze generalized ridged waveguides. The tangential fields in each region are expressed in terms of the product of several matrices, i.e., a functional matrix about x-F(x), a functional matrix about y-G(y) and a column vector of amplitudes. The boundary conditions are transformed into a set of linear equations by taking the inner products of each element of G(y) with weight functions. Two types of ridged waveguide are calculated to validate the theory. Several new modes not reported in previous analysis are presented.
A New Method to Measure the Transmittance of Filter
Authors: Wu Sheng Jiang , Li Dang Juan , Lu Jin Jun
Published: November 2011

Based on the theory of Fabry-Perot interference, we analyzed the inherent relationship between single-wavelength and the spectrometry, established the mathematical model of transformation from angular spectrum measurement to spectral measurement,realized the data conversion between angular spectrum measurement and spectrum measurement; build the experimental platform and got the laser's transmittance by changing the incidence angle of the laser, and given the comparison experiment by using spectrophotometer, measured the spectral transmittance of filters. Comparison of the two measurement, the results show that:it is a feasible scheme that the angular spectrum measurement replace spectral measurement for filter transmittance .
Reliability Evaluation of Electromagnetic Flowmeter Based on Entropy Weight and Fuzzy Theory
Authors: Yu Chun Yu , Zhang Kai Li , Ma De Zhong , Zhou Zhen
Published: November 2011

With regard to the problem that only single index has been used in assessment of reliability, a suitable comprehensive assessment method about reliability index of electromagnetic flowmeter was established, and Mean Time To First Failure(MTTFF), Mean Time Between Failure(MTBF) and equivalent failure rate(D) were selected as the standards of reliability evaluation for the electromagnetic flowmeter in this paper. Because many evaluation elements involved and failure information and evaluation indexes are fuzzy, fuzzy comprehensive evaluation based on entropy weight was introduced to quantify the qualitative evaluation indexes, and indexes weight were determined scientifically by using comprehensive evaluation obtained from combining a subjective expert’s evaluation weight with objective entropy weight. Two kinds of the domestically produced electromagnetic flowmeter were studied, the censored data obtained from the process of consumers’s use were analyzed, and fuzzy comprehensive evaluation method based on entropy weight was used to evaluate the indexes of reliability in two kinds of electromagnetic flowmeter comprehensively. The results show that the conclusion is consistent with the fact, the method can effectively solve the problem existed in current modeling, and evaluation of electromagnetic flowmeter reliability has great practical value in the application.
Wind-Driven Natural Ventilation in an Areaway-Attached Basement with a Single-Sided Opening for Residential Purposes
Authors: Bu Zhen
Published: November 2011

This paper discusses the sustainability of the areaway-attached basement concept with the attentions focused on wind-driven single-sided natural ventilation. First, numerical simulations were performed on an areaway-attached basement with a single-sided opening. Two CFD approaches: Reynolds averaged Navier-Stokes (RANS) and large-eddy simulation (LES) were used and compared with the previous experimental results of effective ventilation rate. A good agreement between the measurement and LES model was found and RANS model tends to underestimate the ventilation rates. Furthermore, Based on LES with the inflow turbulent fluctuations, the mean airflow patterns within and around the areaway-attached basement was investigated for different wind incidence angles to examine the influences of wind direction on ventilation performances.
A Soil Sampling Method Based on Field Measurements, Remote Sensing Images and Kriging Technique
Authors: Quan Quan , Shen Bing
Published: November 2011

How to determine a representative and economical soil sampling method that combines soil properties with advanced technologies has been an unsolved issue in soil related studies. This paper proposes a new method for soil sampling based on some measured salinity data and remote sensing images, as well as analysis of spatial distributions of soil properties in Lubotan land reclamation area in Shaanxi, China. The results showed that with the available data sets of 33 points, up to 101 unknown points can be estimated, and further interpolation of 343 points displayed spatial distribution of soil salinity in the study area, the coefficients of determination (R2) for the predicted soil salinity were 0.817, respectively. A further Kriging analysis for top soil salinity distribution in the study area showed that soil salinity has a medium degree of autocorrelation and low variability. The study in this paper may help understand the effect of soil reclamation efforts and local water management practice.