bluuebunny/crossref_metadata_2025 huggingface dataset:
Data Envelopment Analysis and Malmquist Productivity Index for Measuring Group Performance on Interval Data
Authors: Parchikolae B. Rahmani , Jahanshahloo G. R. , Lotf F. Hosseinzadeh
Published: November 2011

This paper develops measures, based on the Malmquist productivity index, that enables the decision making units internal efficiencies from those associated with their group characteristics. It has been assumed that the levels of inputs and outputs are not known exactly. The analysis involves the construction of an index reflecting the relative performance of example, which can be decomposed into an index for the comparison of efficiency change index and an index for comparison of technological change index. We provide a computational method for extension the Malmquist index group A relation to group B interval data. The utilization of the proposed approach is demonstrated with an illustrative example.
Fuzzy Available-to-Promise System Modelling under Supplier Uncertainty
Authors: Halim Tony , Muthusamy Kanesan
Published: November 2011

Available-To-Promise (ATP) function is an important tool in supply chain management to enhance the responsiveness of order promising and the reliability of order fulfillment. ATP models provide responses to customer order enquiries, based on resource availability, allowing the user to determine whether they should accept the order. Currently, many of the ATP models available adopt a deterministic approach and do not address uncertainties in the manufacturing environment. In this paper, a fuzzy mathematical programming model is proposed to address the problem of order-promising under an environment of supply uncertainty. The model aims to minimize the cost of rejecting orders, failing to meet promised orders and inventory holding cost of the finished products and supply materials. In addition to order promising, the model also performs order-fulfillment and provides a master production schedule of each product and material requirement planning of each supply material over the given planning horizon. To solve the fuzzy mathematical model, an approach based on possibility and necessity theory is applied.
Effect of Cutting Fluid Supply Strategies on Surface Finish of Turned Parts
Authors: Islam M.N. , Rafai N. H. , Heng B. C.
Published: November 2011

This paper presents the experimental and analytical results of different cutting fluid supply strategies—dry, minimum quantity lubrication (MQL) and flood turning in terms of the surface finish of turned parts. Subsequently, the influence of independent input parameters on surface finish is investigated in order to optimize their effects. Three techniques—traditional analysis, Pareto ANOVA analysis, and the Taguchi method—are employed. Initially mild steel AISI 1030 has been selected as the work material. The results indicate that the cutting fluid supply strategy has insignificant influence on the surface finish of turned parts. However, the amount of cutting fluid in MQL showed some influence. Further research on two additional materials, aluminum 6061 and alloy steel AISI 4340, reveals that the surface roughness for different work materials is influenced differently by the cutting fluid supply strategies and there is a scope for optimizing the cutting fluid supply strategy in terms of both method and the amount of cutting fluid. This will reduce the amount of cutting fluids used and consequently, their negative impact on the environment, by avoiding unnecessary applications.
Research on the Safety Evaluation Method of Railway Operation System
Authors: Xiao Xue Mei , Wang Yan Hui , Ling Yuan
Published: November 2011

Based on the analysis of railway accidents and safe operation, a dynamic multi-ring evaluation index (DMEI), whose structure was dynamic and reconfigurable logically, was proposed in the paper. And, Based on the structure of this evaluation index system, an analysis method based on accident chain analysis, which was improved from the order relation analysis method, was proposed in this paper. The improved method can be applied to the safety assessment of railway operation system. Last, by using the safety evaluation method proposed in this paper, the evaluation simulation of railway system operation was done, and then the evaluation results were analyzed and explained in theory.
Design of a Remote, Real-Time Elevator Monitoring System Based on the µc/os-II Operating System
Authors: Guo Gai Zhi , Zhang Peng Ju , Yu Zong Zuo , Wang Hai Long , Shi Yu Li
Published: November 2011

Use of µc/os-II based real-time, multi-task operating system accomplished synchronized task management and communication. An operational simulation interface for real-time monitoring of elevator was designed by hybrid programming using C and assembly languages based on data collected real time in the shared resource taken by visiting of semaphores and message boxes with shared resource in the buffer zone. In the control room, PC monitor displays elevator’s moving direction, position, condition, and any malfunction situations. It was demonstrated that the µc/os-II real-time operating system-based elevator monitoring system could not only be used under DOS window for Windows but can also be easily transferred to micro processor modules with different structures.
A Review of Metaheuristic-Based Product Concept Generation Systems
Authors: Ang M. C. , McKay A. , Ng K.W.
Published: November 2011

The task of designing product forms is becoming increasingly challenging as consumers demand visually pleasing products that meet functional requirements. Researchers have been working on product concept generation systems that support designers in exploring design spaces to produce large numbers of product concepts from which possible solutions can be selected and developed. Such systems typically utilize the searching capabilities of metaheuristic techniques to explore solution spaces and generate variations of product forms. Recent research work in this domain has focused on hybrid approaches that combine metaheuristic techniques with other methods such as shape description and neural network approaches. This paper provides a review of the application, effectiveness and prospects for these approaches.
Design of an Automatic Positioning System Used in Pipe Crawler Weld Based on TMS320DM642
Authors: Guan Yu Jun , Zhou Hao Miao , Sun Jian Guo
Published: November 2011

X-ray Pipe Crawler is the welding seam detection device that widely used in Oil pipeline construction of middle and far distance transmission. In this paper, a method of automatic positioning system used in pipe crawler weld by using DSP is introduced. And investigate the base method of seam image process. The design of an automatic positioning system used in pipe crawler weld based on TMS320DM642 is given. The image edge detection simulation system experiments are based on MATLAB.
Influence of Intermetallics Modification by Melt-Shearing Treatment on Mechanical Properties of Iron-Containing Al-Si-Mg Casting Alloy
Authors: Kim Bong Hwan , Lee Sang Hwan , Lee Sang Mok
Published: November 2011

This study aims to investigate the influence of intermetallics morphological modification on mechanical properties of iron-containing Al-Si-Mg casting alloys. The modification of the intermetallics was performed by using melt-shearing treatment prior to commercial high pressure die casting. The process parameters of the melt-shearing treatment were controlled and optimized based on the theoretical consideration of the intermetallics formation behavior. It was found that the mechanical properties of low-iron containing Al-Si-Mg alloy was improved due to the modification of primary α-Al from dendritic to globular form by the melt-shearing. Regarding to high-iron containing Al-Si-Mg alloy, harmful morphology of intermetallics was successfully modified by the melt-shearing at semi-solid region, which results in the improvement of mechanical properties such as elongation.
Hot Corrosion Studies on GTA Welded AISI 304, Monel 400 Subjected to Air Oxidation and Molten Salt Environment
Authors: Devendranath Ramkumar K. , Arivazhagan N. , Narayanan S
Published: November 2011

An attempt was made to study the hot corrosion behavior on gas tungeten arc welded Austenitic stainless steel AISI 304 and Nickel-copper alloy Monel 400. These materials are widely used in power plant, petro-chemical and marine applications where the weldments are usually subjected to aggressive corrosion environment. GTA welding was carried out using ENiCu-7 and E308L filler wires. Various regions of the weldment of AISI 304, Monel 400 were exposed to the air oxidation as well as in the molten salt environment consist of K2SO4 + NaCl (60%) at 700°C. Mechanical properties of the weldments were also studied. The corrosion products of the weldments were analyzed using SEM/EDAX, XRD analysis.
Development of Defect Free Monel 400 Welds for Marine Application
Authors: Devendranath Ramkumar K. , Arivazhagan N. , Narayanan S. , Narayanan Mukund , Mondody Arjun , Kashyap Raunak
Published: November 2011

Monel 400 is nickel-copper alloy being widely in thermal and nuclear power plants, marine environments because to its outstanding properties include high ductility, good weldability and good corrosion resistance. In the present investigation, an attempt was made to evaluate the mechanical properties of gas tungsten arc welded Monel 400 weldments. Also Monel 400 weldment was studied for the pitting corrosion behavior.
Design and Simulation of Infrared Absorption Based on Hydrogenated Amorphous Silicon Thin Film
Authors: Fu Jun Wei , Li Wei , Wu Mao Yang , He Min , Jiang Ya Dong
Published: November 2011

Hydrogenated amorphous silicon (a-Si:H) thin film has nowadays attracted much attention in a wide range of electronic applications as in image sensors and in solar cells because of its merits and compatibility with semiconductor technology. In this paper, the background of a-Si:H thin film technology and microbolometer technology has been described in details. According to optical admittance matrix method, the multilayer film system based on a-Si:H thin film was simulated by MatLab software, mainly for the simulation of infrared absorption layers and the simulation of microbolometer. The results show that the combination of TiN film and a-Si:H film is suitable for the design of microbolometer within the middle and far infrared wave band (8-14µm), and the infrared absorptivity of the modified microbolometer can reach over 90%.
An Improved Particle Swarm Optimization Approach for Temperature Control in HVAC for the Purpose of Energy Saving
Authors: Zhang Jun , Zhang Kan Yu
Published: November 2011

Good dynamic performance of a system have great significance in the traditional sense, furthermore,it is more important at the point of energy saving. Particle swarm optimization (PSO) is a novel evolutionary algorithm which has a better convergence rate and computation precision compared with other evolutionary algorithms. In this paper an optimal design of PID controller based on particle swarm optimization approach for temperature control in HVAC is presented. The results show the adjustment of PID parameters converting into the optimal point and the good control response based on the optimal values by the PSO technique, and thus it achieves the purpose of energy savings.
Orthogonal Experimental Design Applied in Analyzing Factors Influencing on Heat Transfer Performance of Engine Cylinder Head
Authors: Zhang Ping , Ouyang Guang Yao , Lv Jian Ming
Published: November 2011

Based on orthogonal design, a four factors and four levels experimental scheme were made. On a special test platform, under different heat transferring conditions, temperature fields of cylinder head were obtained. Results showed: among the four kinds of factors, the temperature of coolant water in jacket had serious influence on cylinder head, second was the heating temperature in chamber, third was the flow of coolant water in jacket, the last was surrounding temperature, which can give a gist for further optimizing cooling system of engine.
Research on SSO Caused by HVDC Based on Eigenvalue Analysis
Authors: Zhang Dan , Xiao Xiang Ning , Yang Lin , Gao Ben Feng
Published: November 2011

Subsynchronous Oscillation problems caused by HVDC system are studied and analyzed intensively in this paper based on eigenvalue analysis method. By establishing the small signal linearized model of a typical HVDC system, subsynchronous oscillation characteristics of the system with or without SSDC are obtained. Further more, the influence of SSDC parameters to the system subsynchronous oscillation characteristic can be illustrated clearly. This is significant for SSDC design in order to achieve a satisfied restraining effect. Comparing with more accurate electromagnetic transient simulation results, the consistency of the two methods is verified and it can be demonstrated that eigenvalue analysis method is adequate for studying subsynchronous oscillations.
Development and Realization of Air Flow On-Line Monitoring System in Utility Boiler Based on AC Induction
Authors: Xue Zhao Mei
Published: November 2011

Combustion control is the most important aspect in boiler unit operation, while the boiler air flow monitoring is the main content of combustion monitoring. Therefore, real-time and accurate online monitoring of the air flow in boiler main and branch pipes is of great importance for the economy, safety and environmental protection of the boiler combustion. This paper mainly introduces an air flow on-line monitoring system in utility boiler based on AC induction. By using the international advanced AC charge-coupling technology and digital signal processing technology, it overcomes the present technique difficulties of air flow on-line monitoring system. It has the advantages of high measuring accuracy and easy installation and maintenance. Also, it is applicable to the air flow on-line monitoring in different types of air ducts, therefore, it can bring certain economic benefits and have the prospect of popularization and application.
Distributed Contact Model for Indeterminate Grasp Force Analysis towards Heavy-Duty Manipulation
Authors: Mao Jin Cheng , Yang Wen Yu
Published: November 2011

This paper presents a new contact model to describe the contact constraints for heavy-duty manipulation. This contact model considers the contact area as a surface, which can translate three-dimension forces and torques. The contact deformations which are resulting from the large contact forces cannot be ignored. Distributed linear elastic contact model is adopted to describe the relationship between contact force and contact deformation. A case study is carried out in this paper based on this contact model for the grasp force analysis of heavy-duty manipulators.
Research on the Energy Efficiency Test System of the Induction Motor
Authors: Fan Ying , Yan Hua Guang , Jiang Li Min , Zhang Xin
Published: November 2011

As one of the national medium-long term energy conservation special planning, the energy efficiency for motor system is key projects. On the other hand, a large number of motor systems have a wide range of applications in power system, and almost occupy 60 percent of the end use energy consumption. It is very important to improve motor system energy efficiency for end use energy efficiency improvement. This paper introduces the energy efficiency evaluation methods and testing system for motor and the high-efficiency motor, by the system, energy conservation certification evaluation and energy label technology service are given, thus, the motor efficiency can be known by the testing. The system can help manufacturers and users to make right decision during the models producing and selecting, and it can be meet the technique requirement of the smart grid construction.
Skew and End-Teeth Optimization in Reduce Permanent-Magnet Linear Synchronous Motor Normal Force Fluctuation
Authors: Xia Jia Kuan , Li Wei Yang , Shen Li
Published: November 2011

Permanent-magnet linear synchronous motor (PMLS-M) exist the problem of normal force fluctuation, especially in the servo feeding system of high-precision CNC machine tools, the normal force fluctuation can cause the feeding table in vibration and produce resonance with other moving components of the servo feeding system .Analysis shows that detent force fluctuation is the predominant factor. Adopt the methods of end-teeth optimization combine with skew or V-skew can effectively reduce the detent force fluctuation. By using the Fourier regression analysis and limited enumeration method to calculate the optimal parameters, and applying the layered finite element analysis for simulation. The results of simulation prove that with the precondition of the thrust force loss slightly, adopt those optimization methods can reduce the normal force fluctuation significantly.
Precision Analysis of Simulation Systems with Hardware-in-Loop Caused by Performance of Three-Axis Virtual Flight Motion Simulator
Authors: Wang Tao , Zhu Ming Chao , Yin Sheng Li , Jia Hong Guang
Published: November 2011

Simulation systems with hardware-in-loop are composed by three-Axis virtual flight motion simulator, simulation computer, load torque simulator, and visual simulation systems. Three-Axis Virtual Flight Motion Simulator are used to simulate the attitude of missile in simulation system with hardware-in-loop, so its performance influenced the result of simulation directly. This paper mainly analyzed the factors which influenced the performance of a three-Axis virtual flight motion simulator which we are used now in the lab, then analyzed the entire simulation system’s error caused by these factors through numerical simulation method. By analysis we can see that bandwidth is the main factor influenced the precision of simulation systems with hardware-in-loop, mechanical device installation error and measurement error may also cause some errors of the systems at the same time.
Numerical Analysis of Minicar Radiator Flow Resistance
Authors: Liu Chuan Bo , Mo Yi Min , Li Ming
Published: November 2011

In order to seek methods of reducing the coolant resistance of radiators in mini-vehicle, the resistance distribution in minicar radiators was obtained by carrying out numerical simulation to coolant flow field of the radiators. The analysis indicated that the coolant resistance mainly composed of two parts: the resistance along radiating pipes, the inlet and outlet resistance of the water tank. Reducing the surface roughness of coolant pipes could lower the resistance along pipes. Slowing down the changes of the inlet and outlet section could reduce the local resistance.
A Stator Flux Estimation Method Based on Duty Cycles of Inverter Switching
Authors: Wu Yi Feng , Deng Zhi Quan , Wang Yu
Published: November 2011

This paper presents a stator flux estimation method based on duty cycles of inverter switching. The stator flux is calculated by integrating the back electromotive force, which is the terminal voltage minus the voltage drop on the stator resistance. The terminal voltage mentioned above is calculated by the duty cycles of inverter switching and dc link voltage, while the duty cycles is derived in the digital control system of induction motor based on the DSP. Without employing voltage sensors to measure phase voltage, the proposed flux estimation method is cost effective and error reducing. The method is also effective in fault-tolerant operation when the motor works with two phases. Experimental results verify the effectiveness of the proposed method.
Fractal Analysis of Soil Profile Roughness
Authors: Hou Zhan Feng , Chen Zhi , Li Lin , Han Jing Yu , Lu Zhi Xiong
Published: November 2011

In this paper, we address the issue of soil roughness characterisation in the case of agricultural fields having different tillage (roughness) states, that is ploughed, harrowed and rolled surface. By using a laser profiler, the surface height variation trace of three types of tillage soil profiles are obtained. Using this dataset the range of RMS height, autocorrelation length and the fractal characteristic values associated with each agricultural roughness state is estimated, The result show that fractal dimension turned out to be a suitable index for distinguish the different tillage states. But there is no one-to-one correspondence relationship. A soil roughness index was found to be appropriate for the quantification of soil surface roughness.
Design of the Underwater Acoustic Signal Acquisition System Based on the Pipelined Twin-AD
Authors: Zhao Guo Ku , Ning Shu Shi , Cai Zhao Wei , Xu Ze Qian
Published: November 2011

In order to improve the accuracy of the underwater acoustic detection effectively, the digital signal acquisition circuxcA`\\it is a necessary deceive, which must have enough high data acquisition rate. Therefore the high frequency operating clock is employed in the traditional digital signal acquisition circuit. However, the high frequency operating clock will bring troubles to the design of hardware and software, and the power consumption and interference of the system are both increased. According to the principle of the pipelined system, the operation of AD deceive is divided into two process, including the conversion starting and data reading. The FPGA is employed to produce control signals which make twin-AD work in proper state. The design of the underwater acoustic signal acquisition system based on the pipelined twin-AD is presented here. On the base of the system design, simulation, implementation, the hardware experiments are completed. The results show: driven by the operating clock with same frequency, the underwater acoustic signal acquisition system based on the pipelined twin-AD can obtain the acquisition rate which is twice as the traditional data acquisition system.
Measurement Technology Research on Target and Projectiles’ Miss Distance Based on Digital Image Processing
Authors: Ma Zhi Qiang , Sun Shi Yu , Cheng Yuan Zeng , Wang Chun Ping
Published: November 2011

At the closed-loop calibration research of anti-aircraft weapons systems, the miss distance between target and projectiles is difficult to obtain accurately. In order to solve this problem, this paper provided using the digital image processing technology to research the miss distance measurement methods, focusing on the image filtering technology, edge detection technology and target recognition technology. According to the simulation results, the paper selected the adaptive median filtering to remove image noise, adopted the edge detection method based on the iterative threshold to obtain target edge and used template matching technology to identify the target in the image. Finally, according to the principle of image measurement technique, using centroid tracking measurement technology to achieve the miss distance measurement. The application of digital image processing technology makes the miss distance measurement become simple, effective and convenient. This measurement method enables to save money, improve accuracy, get results in real time and have a high research value.
Prediction Method of Coal Fracture Based on Failure Approach Index and Hoek-Brown Criterion
Authors: Wang Xin , Zhang Li Song , Yan Xiang Zhen
Published: November 2011

According to Mohr-Coulomb criterion, the yield approach index (YAI) of Hoek-Brown criterion is derived. The rock-mass intact coefficient KV is introduced, and coal failure approach index is defined by combining failure degree. On the basis of logging data and stratified in-site stress model, the failure approach index and yield approach index are calculated in wellbore direction. Based on FAI values, coal fracture degree is divided four grades of A, B, C, D, and coal fracture classification method is proposed. Taking ZP-1 Well in QinShui basin as an example, the distribution regularity of coal fracture degree is predicted by the method. The results indicate that failure approach index of ZP-01 well is between 0.8-1.2; the section of 551-552.7m of coal seam is fractured (grade A), and the rest section of coal seam is regarded as grade B. Through electron microscope to scan coal sample structure, the results agree well with the prediction results, therefore the classification method is reliable. Depending on theory results, computer program is corresponding developed.
An Ice-Detecting and Ice-Melting System of Electricity-Transmitting Lines Based on ZigBee Wireless Communication
Authors: Song Cheng Yan , Liu Bai Qing , Jiang Jing , Li Feng Ling
Published: November 2011

An Ice-Detecting and Ice-Melting System of Electricity-Transmitting Lines based on ZigBee Wireless Communication uses ZigBee wireless network as the flat. Sub nodes are placed at some places of the electricity- transmitting lines. The sub nodes detect the icing status of electricity-transmitting lines by using the vibration tube ice sensors and send the ice signals to the main node via the ZigBee wireless network. The main node sends the ice signals to PC via USB interface and launches the ice-melting system at the same time. The principle and sense organ structure of the vibration tube ice sensor are briefly introduced. The hardware and software designs of sub node and main node are stress explained. Finally, the theory of the controllable inductor and capacitor compensation ice-melting system is particularly expatiated.
Fault Diagnosis Method in Controlled Rectifier Based on Support Vector Machines
Authors: Liu Hong Da , Yue Wen Jie , Lan Hai , Zhang Dian Hua
Published: November 2011

Based on support vector machines (SVM) theory, a new method of fault diagnosis for controlled rectifier circuits is proposed in this paper. Fault diagnose method of power electronic converter has been studied on the basis of direct waveform analysis and SVM. Three-phase bridge rectifier circuit fault is presented as an example, coupled with the results of a certain power electronic circuit experiment, indicates that the method can accurately diagnose and locate fault for controlled rectifier circuits, which is justified practical and applicable for controlled rectifier circuit fault diagnosis.
Measurement Research on Magnetic Properties of Electrical Steel Sheet under DC Bias Conditions
Authors: Bai Bao Dong , Li Chong
Published: November 2011

In order to acquire the magnetic properties parameter of transformer core under DC bias conditions, also to reveal the accurate analysis and judgment on the operating characteristics of transformer under the DC bias, this thesis utilized two Epstein Square devices to proceed the experiment and measurement on magnetization curve of some certain transformer which used the 30ZH120 electrical steel sheet under four different lap ways. This paper provided the measure method of bias magnetic density under laboratory conditions, meanwhile it offered the bias magnetization curve and the loss curve. The measure consequence comparison between the electrical sheet steel and the transformer model showed that direct oblique way lap can be more realistically reflected the magnetization characteristic of transformer which worked in the DC bias conditions. For Large Transformer which was difficult to measure the magnetic properties provided a convenient measurement methods, and offered the experiment facts to the theory study of the DC bias transformers.
Design of External-Rotor Ferrite Permanent Magnet BLDC Motor
Authors: Xu Chang Ying , Li Quan Min , Huo Chun Ling
Published: November 2011

In this article, the general design of external-rotor ferrite permanent magnet BLDC motor is required. Based on the principle of cost reduction, we designed and manufactured motor prototype, and simulated it with the finite element method for electromagnetic field, and had no load and load test to verify the legitimacy of motor design parameters. We made a system test of fan-driven by a prototype, and the measured data showed that the external-rotor brushless DC motor had good performance and lower cost and had the advantages for industrial production.
Study on Generation of Digital Micro-Fluids Based on Surface Acoustic Wave
Authors: Wei Yi Qing , Zhang An Liang
Published: November 2011

The generation of digital micro-fluid is indispensable operation unit for lab-on-a-piezoelectric-substrate. A new generation method of digital micro-fluid is proposed in this paper. An interdigital transducer (IDT) and a reflector were fabricated on 1280 YX-LiNbO3 substrate, which was used to excited surface acoustic wave. A needle with 400um inside diameter connected with a syringe was on the piezoelectric substrate, of which space could be adjusted. The needle tip and the piezoelectric substrate were coated with Teflon AF 1600. Water was used to generate digital micro-fluid experiments due to most samples or reagents being water solution. Experimental results show that the volumes of generated digital micro-fluid are relied on the space between the needle tip and the piezoelectric substrate, contact angle of the needle tip and RF power acted on the IDT. When the flow velocity of the syringe being 2.269 mm/min, space between the needle tip and the substrate being 0.98mm and 34mdB RF signal power, the volume of the generated water digital micro-fluid is 2ul. Change the space and RF signal power, the volume of generated water digital micro-fluid is also different. The method of generating digital micro-fluid can be greatly useful for Lab-on-a-piezoelelctric-chips.
Based on Time Series Prediction of Photovoltaic Power Plant Output
Authors: Li Wei Guo , Liao Zhi Min , Sun Xue Lin
Published: November 2011

With the PV power system capacity continues to expand, PV power generation forecasting techniques can reduce the PV system output power of randomness, it has great impact on power systems. This paper presents a method based on ARMA time series power prediction model. With historical electricity data and meteorological factors, the model gets test and evaluation by Eviews software. Results indicated that the prediction model has high accuracy, it can solve the shortcomings of PV randomness and also can improve the ability of the stable operation of the system.
Design of Ultrasonic Gas Temperature Measurement System with Humidity Self-Correction
Authors: Yao Ming Lin , Guan Yu Jun , Dong Cui Ying
Published: November 2011

In the ultrasonic gas temperature measurement system, the principle is that the velocity of sound in gas is a function of temperature. But because the propagation speed of ultrasonic wave can be easily affected by humidity, the accuracy of the gas temperature measurement will be affected too. This dissertation will implement the ultrasonic gas temperature measurement system with humidity correction suitable for all kinds of environment humidity. This type of ultrasonic technique is a highly efficient algorithm with the advantages of both time-of-flight method and phase shift method. And the system is realized with a single-chip microcomputer-based with a relative humidity/water vapor pressure meter. The main advantages of this ultrasonic temperature measurement system are high resolution, using narrow-bandwidth ultrasonic transducer of low cost and ease of implementation.
Measuring the Shielding Effectiveness of Small Enclosures
Authors: Cheng Er Wei , Wang Qing Guo , Zhou Xing
Published: November 2011

Research on the shielding effectiveness (SE) of small shielding enclosures has attracted more and more attention since small shielding enclosures are widely applied in many areas, such as aviation electronics, testing equipment and industrial control. There is still not proper standard to follow for SE tests in a reverberation chamber. The SE of a small enclosure is simulated and measured by moving a field probe along particular positions inside the enclosure using a reverberation chamber.
Magnetic Levitation Permanent Magnet Linear Synchronous Motor Electromagnetic Analysis
Authors: Lan Yi Peng , Li Cheng Jun
Published: November 2011

According to the problem of the friction between the mover and the static guide rail in the linear motor drive system of CNC machine tool, this paper proposed the direct magnetic levitation permanent magnet linear synchronous motor to achieve friction-free feed. The mover of the direct magnetic levitation permanent magnet linear motor consists of two sets of windings. One is the thrust winding, which is used to generate electromagnetic thrust, the other is the suspension winding, which is used to generate magnetic levitation force. The mathematical model of the motor’s electromagnetic thrust and levitation force is derived by the Maxwell stress tensor method. Ansoft is used for making finite element analysis of the motor’s electromagnetic thrust and levitation force. The results verified the correctness of the mathematical model. The feasibility of friction-free feed with two-winding direct magnetic levitation permanent magnet synchronous motor is proved.
Maximum Adhesion Control of Railway Based on Sliding Mode Control System
Authors: Li Yun Feng , Feng Xiao Yun , Liu Rui Kuo
Published: November 2011

The wheels will idle when the relative slipping speed between the wheel and rail exceeds the reference slipping speed. In order to avoid this phenomenon, the simplified model of wheel-rail traction torque transmission was established. And the adhesion coefficient and vehicle velocity are got through the disturbance observer. Then the recursive least squares method was used to forecast the slope of the adhesion-slip curve. Sliding variable structure controller was used to control the error of wheel velocity and reference velocity. From the results of simulation, this method can be effective to maintain the adhesion coefficient around the maximum. And the slipping speed approached the reference value, so the damage for wheel and rail was effectively prevented which achieved the desired effect.
A New Real-Time Gas Well Productivity Evaluating Method
Authors: Tian Leng , Shen Ying Hao , Wang Shao Jun , He Shun Li
Published: November 2011

With the continuous development, the gas well productivity will decrease. The deliverability test can be used to evaluate gas well productivity, but this method always needs long test which will affect daily production seriously, especially for low permeability gas wells, also there always isn’t enough data in the field. Aiming at this problem, this article presents a new real time method to get the gas well productivity. This new method avoids deliverability test and only needs daily production and wellhead pressure data, so the analysis process is easy and this method has strong practicality. It is proved that this new method works well in the field case.
Traveling Wave Current Polarity Comparison Protection Using Wavelet Modulus Maxima for HVDC Transmission Lines
Authors: Duan Jian Dong , Lu Wen , An Lin
Published: November 2011

ABB and SIEMENS schemes based on the voltage change rate are the existing main protection for HVDC transmission lines. But the analysis and simulation tests show that these protection schemes may be unreliable as high impedance faults or as disturbances of above 2% noisy. The paper presents a new protection scheme of traveling wave current polarity comparison for a bipolar HVDC transmission line. The traveling wave current polarity is represented by the wavelet modulus maxima (WMM) of the fault current traveling wave. The traveling wave current polarity comparison protection scheme is evaluated by PSCAD. The extensive simulation studies show that the proposed scheme is reliable to distinguish internal faults from external faults of HVDC transmission lines. And the protection scheme is immune to high impedance faults and able to accurately detect the fault line under the electromagnetic coupling circumstance.
The Correlation between MSCT for Lung Volume and Airway Measurements and Pulmonary Function Test
Authors: Deng Zhen Sheng , Gao Rui Ling , Wang Fang
Published: November 2011

Objective To study the correlation between the airway dimensions from third to five generation of bronchi, and pulmonary function test(PFT) results in patients with chronic obstructive pulmonary disease(COPD) by using inspiratory and expiratory multisection computed tomography(MSCT). Materials and Methods The study included 19 patients with COPD who underwent both inspiratory and expiratory CT. For each patient, airway luminal areas and wall thickness from the third to fifth generations of RB1 and RB10 were measured. Correlations between these parameters and PFT results were evaluated. Results The correlation coefficients between airway luminal at expiratory CT and PFT results were higher than those for inspiratory CT, and improved as the airway size decreased from the third to the fifth generations. Conclusion Some parameters of airway luminal are significantly correlated with PFT. MSCT can be used to assess the pulmonary function of patients with COPD.
System for Detecting the Defects of Steel Tubes Based on Electromagnetic Acoustic Technology
Authors: Shi De Quan , Gao Gui Li
Published: November 2011

According to the electromagnetic acoustic technology, an automatic system was constructed to detect the defects of steel tubes. On the basis of analyzing the principle of detecting the defects of steel tubes by the electromagnetic acoustic technology, an electromagnetic acoustic transducer was designed to transmit and receive the electromagnetic acoustic signals. The data were acquired by the high-speed data acquisition card and transferred to computer by PCI bus, and then analyzed and processed by computer. In addition, the selective frequency and amplification technology was used to process the weak received signal, which improved the anti-jamming ability of the system. Experiments on steel tubes with different diameter through-hole were performed, and the res
Design and Simulation of Variable Speed Constant Frequency Brushless Doubly Fed Wind Power Generator
Authors: Wu Kai Jun , Wang Yan Yan
Published: November 2011

Brushless Doubly-fed Machine (BDFM) is a new inverter-driven induction motor, and it has broad prospects in wind power generation. This paper analyses the structure and VSCF electricity generating principle of a cascade Brushless Doubly fed Wind Power Generator, deduces the BDFG’s mathematical model, The variable structure control (VSC) was used to the active and reactive power decoupling control of the BDFM, analysis the relation of electromagnetism and energy balance .Finally, simulation and analysis of the whole system and control strategy are carried through in matlab/simulink soft. According to these results, the correct of parameters and simulation model for BDFM is proved.
Computational Models for the Static and Dynamic Analyses of Laminated Composite Plates
Authors: Shantharam Patil S.
Published: November 2011

The present study is to assess the accuracy of the few computational models based on various shear deformation theories in predicting the static and dynamic behaviour of antisymmetric angle-ply laminated composite plates. In the present investigation two higher order refined computational models incorporate the laminate deformations which account for the effects of both transverse shear and normal deformation and a non-linear variation of in-plane displacements are used. In addition to above, few higher order models and the first order model developed by other investigators and available in the literature are also considered for the evaluation. The equations of equilibrium are obtained using Principle of Minimum Potential Energy and the equations of motion using Hamilton’s principle. Solutions are obtained in closed-form using Navier’s solution technique. The solutions of the static analysis are obtained by solving the boundary value problem and the natural frequencies are obtained by solving the eigenvalue problem. The accuracy of the solutions obtained from the different models are established by comparing the results with the solutions wherever available in the literature. Results generated independently using the various models are presented for antisymmetric angle ply composite plates which will serve as benchmark solutions for future investigations.
Developing Uniaxial Tensile Test as an Alternate Method for Thermo Mechanical Process Evaluation
Authors: Priadi Dedi , Napitupulu Richard A. M. , Siradj Eddy S.
Published: November 2011

The alternate method for evaluating the thermo mechanical process has been developed. Small attention has been paid to the mechanism of plastic deformation especially plane strain analysis. Modified the specimen geometry and using uniaxial tensile test was done to view the process. Experimental results show that the forming limit diagram as one of the formability characteristic can be view the plane strain condition that present on the thermo mechanical process. The microstructure result shows that there is a similar grain structure between hot tensile test and hot rolling results as one of thermo mechanical process method. It was concluded that the uniaxial test using universal testing machine could be done to evaluate the thermo mechanical process.
Study of Modified Sliding Mode Control Strategy for STATCOM with LCL Filter
Authors: Hou Rui , Li Cai Ping
Published: November 2011

This paper studies the control strategy of STATCOM with LCL filter. The STATCOM sixth orders differential equations in dq coordinate separate to two parts. Invert system theory deals with their uncoupling and nonlinearity. Then the sliding mode control strategy is used to the differential equations. Finally simulation results show validity and effectiveness of the design by comparing with PI controller.
Mixed-Oxide Sorbent for Moderate-Temperature Removal of Carbonyl Sulfide
Authors: Zhao Hai , Xu You Ning , Liu Jun Qing
Published: November 2011

Fe-Mn-Ce oxides were used to remove carbonyl sulfide from syngas at moderate temperature in this work. Tests showed that the sorbent exhibited a high reactivity and sulfur capacity. At the same time, the sorbent exhibited better performance under cyclic operation. Thermogravimetry was used to study reaction kinetics when gas contained different gases on the desulfurization reaction. It was found that the apparent reaction activation energy was smaller in the atmosphere of reaction gas contains hydrogen than that in the absence of hydrogen.
Research on Electric Linear Compressor for New Energy Vehicles
Authors: Shi Yan , Li Zong Li
Published: November 2011

New energy vehicles have bright prospect in the near future. In new energy vehicles some parts which are driven by engine through transmission will be replaced by electric drive, such as refrigeration compressor used for air conditioning and air compressor used for air brake system. Because of advantages, such as high efficiency, low friction, compact structure, and so on, linear compressor is suitable to solve above problems. In this paper a novel electric linear compressor is presented. Research work, such as simulation, structure design, control design, has been done. Further experiments are being done by my research team. We believe that electric linear compressor is worthy of being researched to popularize new energy vehicles.
Whole Transfer Matrix Method for the Critical Speeds of Skew Gear Transmission System
Authors: Gang Xian Yue , Chai Shan
Published: November 2011

Whole transfer matrix method is a powerful tool for calculating the critical speeds of multi-rotor system. With vector algebra, the six DOF relative displacement of a skew gear pair is deduced, then exciting force and moment generated by engagement force is calculated. By summing the inertia force and engagement loads, the whole transfer matrix of a skew gear pair is established. A numerical example illustrated the effect of different gear parameters on the critical speeds of the gear transmission system.
The Simulation and Research of Chaos in Current-Controlled Boost DC / DC Converter
Authors: Zhen Wang , Liu Xue Feng
Published: November 2011

For the non-linear phenomena of the switching power supply, the discrete mathematical model of current-controlled Boost DC/DC converter has been presented in this paper, according to the switch maps. The results of simulation and experiment are derived, and the variable is the current of inductor. The accuracy of the model has been verified by the results of simulation and experiment which reveales the DC / DC converters from the bifurcation and eventually to the phenomenon of chaos. The theoretical basis using or avoiding chaos is provided for the power supply design.
Heat Exchanger Optimization Analysis of Aircraft Environmental Control System
Authors: Li Hong Bo , Dong Xin Min , Guo Jun , Chen Yong , Li Ting Ting
Published: November 2011

An entropy generation analysis method based on the second law of thermodynamics was used to component level optimization design of aircraft environmental control system in this paper. Through analyzing the air flow process in environmental control system, the function relationship between system entropy generation and present initial conditions was achieved. Along with the heat exchanger design calculation process, as the bleed air pressure and cabin design temperature change, the effect of the ratio between the heat exchanger heat side flow length, cold side flow length and height on whole system entropy generation was obtained. The results obtained in this paper have some guidance function on aircraft environmental control system optimum design.
The Excitation Controller for A Synchronous Generator Based on Nonlinear Optimal Control
Authors: Yang Jin Ling , Han Ru Cheng
Published: November 2011

A nonlinear optimal controller for excitation control of synchronous generators is presented. Based on differential geometry theory, the controller is designed by transforming the nonlinear system to an equivalent linear system. The analysis and simulation of a single-machine infinite-bus power system indicate that the stability of the proposed controller better than the stability of conventional linear controllers
Design of Three-Dimensional Wireless Power Receiving Coil for MEMS
Authors: Li Yang , Xue Kai Feng , Ping Huang
Published: November 2011

In this paper, a micro three-dimensional wireless power receiving coil is designed and powered by a set up wireless energy transmission system. Energy receiving performances of the receiving coil is studied. By experiments, coupling coefficients between the transmitting coil and each winding of the receiving coil are caculated at different attitudes. The experimental results confirm that the receiving coil can receive energy from three orientations and three orthometric windings can compensate each other effectively at different attitudes. Then a micro rectifier and regulator circuit are designed and fabricated which is used for a self-made camera system. Based on this, the actual output voltage is measured. The experimental results verify that the efficiency and stability of the three-dimensional receiving system can meet practical application.
Design of Control System Based on PLC for Polycrystalline Silicon Decomposition Furnace
Authors: Han Qiang , Luo Yuan Lin
Published: November 2011

It requires high security for useing silane decomposition reaction to produce the polycrystalline silicon. For this reason, the paper introduces the central facilities of the polycrystalline silicon production, and bases on production process, to devise a control system which combines PLC and industrial ethernet technology. The system controls temperature and pressure of the decomposition furnace, cooling water system, and production process. The practical result showes that the system is reliable and steady. It meets the requirements of process.
Tubular Permanent Magnet Linear Synchronous Motor Thrust Fluctuation Optimization
Authors: Zhao Jing Hong , Zhang Jun Hong
Published: November 2011

The thrust fluctuation optimal design of the tubular permanent magnet linear synchronous motor is the key to sinusoidal flux density wave degree in theoretical analysis. And the paper analyses the law of different parameters on the flux density waveform. The axial magnetized linear motor is optimized. The measures which inhibited thrust fluctuation is obtained. It has guidance action in motor designing. It has practical engineering value.