bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on a New Type of Center of Mass Measuring Instruments
Authors: Wang Fu Sheng , Bao Gang
Published: September 2010

The accurate measurement and control of center of mass (CM) in mass properties for satellite attitude control are the most important. In order to accurately measure CM, this paper describes a new type of CM measuring instruments which are particularly recommended for determining mass properties of rockets, satellite and ballistic objects. A spherical air-bearing supports a precision rotary table and acts as a frictionless pivot axis for measuring unbalance moments due to the displacement of the test part CM relative to the central axis of the bearing. This paper emphasizes the research on reasons and laws of the load table CM offset caused by the elastic deformation, and according to curve theory of thin plates derives the formulary for the element center of mass displacement of the finite element and for the platform structure center of mass elastic displacement, and calculates the CM elasticity offset and the unbalance moment caused by the deformation of loaded table. The research results provide bases for the structure design of rotary tables.
Analysis on Degree of Freedom of Leg Joint of Humanoid Robot for Fashion Show
Authors: Liu Su Yi , Xu Yun , Yin Min
Published: September 2010

According to the effect of the human joints and the motion characteristics of the models’ footstep, combining with the distribution condition of degree of freedom of biped robots lower extremity structure in and abroad, we determine the number of the degree of freedom of robots legs is 12. Hip joint which has the characteristics of left and right axial rotation at horizontal direction, anteroposterior axis rotation and vertical axial rotation has 3 degrees of freedom. Ankle joint has 2 degrees of freedom which can rotate in left, right, pre and post directions is similar with the human ankle. Knee joint has a degree of joint and it extend the legs. The key of the design of humanoid robots is the joints design. The design of degrees of freedom of the joint is very important for whether the robots can walk successfully.
Dynamic Characteristic and Experiment Research of a Rotor-Bearing System Supported by Oil-Film
Authors: Li Chao Feng , Dai Ji Shuang , Li Xiao Peng , Wen Bang Chun
Published: September 2010

The FEM was employed to establish a nonlinear dynamical model of a rotor-bearing experimental system. The fixed interface mode synthesis dimension reduction method was adopted to to save the computing time.The Newmark-β method was employed to solve the reduced model numerically. And the three-dimensional spectrogram, bifurcation diagram, three-dimensional amplitude diagram, chart of axis trajectory, etc were used to analyze the nonlinear characteristic of the dynamic system comparing with those results of the experimental system. Results show that the numerical dynamic model can accurately reflect the characteristics of the nonlinear experimental system. So, it is very important practical significance to apply FEM and dimensional reduction theory into the research of the local nonlinear rotor system, which can provide more accurate verification and reference for the advanced nonlinear dynamic design of the complex rotor system.
Design and Fabrication of Nanocomposite Tool Materials
Authors: Yang Fa Zhan , Zhou Jian Qiang , Meng Guang Yao , Zhao Jun , Li Chang He
Published: September 2010

Nanocomposite tool materials are very important in engineering field for their advantage in mechanical properties and have a good foreground in the coming years. However, there are lots of puzzles in the materials design theory. So in this paper, a new nanocomposite tool materials design method is proposed based on the interface debonding theory. The wild phase content can be fixed by calculating the debonding interface rate and the strength requirement of the tool materials. Therefore, an experiment is carried out to fabricate WC based nanocomposite tool materials under the guider of the interface debonding theory. Results show that the experimental data is in accordance well with the calculation and the model is proved to be correct.
The CFRP Material's Mechanical Performance and Application
Authors: Zhao Jun , Liu Quan Sheng , Shi Kai
Published: September 2010

This paper analyzes the normal section capacity of the reinforced concrete paste with CFRP. Based on the models under different pasting conditions(U model, one layer at the bottom plus one layer of U model, two layers in the bottom), and experiments on the reinforced concrete beams with CFRP, we will analyze the failure mechanism and failure mode of reinforced concrete beams, and calculate the limit bending capacities. The results are directly applied to practical project.
Three-Dimensional Sonic Band Gaps Tunned by Material Parameters
Authors: Zhou Xiao Zhou , Wang Yue Sheng , Zhang Chuan Zeng
Published: September 2010

In this paper, band gaps tunned by material parameters in three-dimensional fluid-fluid sonic crystals are studied. From the basic wave equation, it is found that the material parameters directly determining the three-dimensional sonic band gaps are the mass density ratio and bulk modulus ratio. The calculation of the sonic band gaps is completed by the plane-wave expansion method. The effects of these parameters on sonic band gaps are discussed in details for the simple-cubic (sc), face-centered cubic (fcc) and body-centered cubic (bcc) lattices. The results show that the first potential sonic band gap easily appears at both small mass density ratio and bulk modulus ratio, and becomes wider with both of these two parameters decreasing. The bulk modulus ratio plays a more important role than the mass density ratio in tuning the sonic band gaps. The present analysis can be applied to artificially design band gaps.
The Effect of Material Flow Stress on Analytical Simulation of Machining
Authors: Li Bing Lin , Ling Ling , Hu Yu Jin , Wang Xue Lin
Published: September 2010

The flow stress data of the workpiece are extremely crucial for the cutting simulation. The study shows how the input data affect the analytical predictions of cutting force and temperature. The Johnson-Cook material model is used to represent workpiece flow stress in the primary shear zone. A thermomechanical model of orthogonal cutting is proposed based on the main shear plane divides the primary shear zone into two unequal parts. Five different sets of workpiece material flow stress data used in the Johnson-Cook’s constitutive equation are chosen and make the sensitivity analysis for analytical model. Simulation results were compared to orthogonal cutting test data from the available literature, and find the effects of flow stress on analytical model was different from that for finite element model.
The Morphology and Phases of Ni-Se Powders Prepared by Hydrothermal Method
Authors: Liu Ke Gao , Liu Ya , Xu Bin
Published: September 2010

Ni-Se powders synthesized by hydrothermal co-reduction method from NiCl2.6H2O and SeO2 at 95～220 °C. The phases and morphology of the products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) respectively. Experimental results show that, Ni0.85Se can be synthesized at 95～220 °C while noticeable impurities appeared at lower reaction temperatures. The products with single-phase Ni0.85Se obtained at 200 and 220 °C show hollow sphere structures with diameters of about 150 ~ 700 nm, which have complete and regular shape but no holes.
Study on the Morphology and Phases of Cu-Se Powders Synthesized by Hydrothermal Co-Reduction
Authors: Liu Ke Gao , Pang Bo , Wang Zhi Gang , Xu Bin
Published: September 2010

Cu-Se compound powders are synthesized by hydrothermal co-reduction from CuSO4•5H2O and SeO2 in deionized water at 120～200 °C. The phases and morphology of the products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) respectively. Experimental results show that, the CuSe phase can be synthesized at 120,150,180 and 200 °C, however, the purity phases become more with the temperature decreasing. It indicates that the reaction is more incomplete at lower temperature. Hexagonal flakes with side length 100～400 nm can be observed in the products at 150,180 and 200 °C, among which only the product prepared at 180 °C has the hexagonal flakes with good dispersity and homogeneous size with 200 nm length.
Research on NC Enveloping Machining for Complex Inner Spiral Surface
Authors: Sun Xing Wei , Hou Guang Zheng , Zhang You Jun , Wang Ke
Published: September 2010

The key parts are the stator and the rotor to realize the function of single screw hydro-mechanical. Along with the further improvement of performance requirement of mechanical product, it’s obvious that the general screw mechanical with rubber bushing stator can’t meet the requirement. So the process technology of inner helical curved surface with metal stator becomes the key technology to improve the screw mechanical property in the world. Considering the special structure of single-screw pump stator bush, a new method enveloping boring without instantaneous velocity center was presented in this paper. Based on motion principle of screw bush pairs and practical theory of enveloping boring without instantaneous velocity center, this method realizes the boring machining for inner spiral surface of stator on NC machine. In this paper, the motion regular pattern of screw in bush was studied, and the basic principle of enveloping boring without instantaneous velocity center was represented. In the end, the feasibility of this method was proved. The new method provides a theoretical basis for the machining of stator inner helical curved surface and the development of machine tool.
Analysis on Perforation of Cone-Nose Projectile to Composite Laminated Aluminum Foam Target
Authors: Bao Yong Gang , Zhang Nian Mei , Yan Xiao Peng , Yang Gui Tong
Published: September 2010

The perforation of composite laminated aluminum foam target against rigid projectiles is studied. The dynamic cavity expansion theory is applied to formulate analytical model and study the perforation resistance of the projectiles. The perforation process can be divided into 11 stages. The perforation resistance expression is derived and applied to analyze the penetration depth of cone-nosed projectiles into the aluminum foam target. The velocity limit and residual velocity are obtained by solving the series of motion equations. The effects of initial velocity, the half-cone angle of the projectile, the density and thickness of each layer on the penetration resistance are investigated. The energy absorption capacity of the composite target material is evaluated.
Analysis on a Steel-Concrete Hybrid Structure Temperature Effect and Supporting Block Design
Authors: Yao Ze Liang , Bai Guo Liang , Dang Fa Ning
Published: September 2010

The steel-concrete hybrid structure is a new special industrial structure in large thermal power plants. It is composed of a spatial steel truss and steel-concrete tubular columns. Its stiffness and mass is highly non-uniform at vertical direction. Its temperature effect is obvious because its steel truss is a high order statically indeterminate structure. Types and characteristics of temperature load prescribed in codes are introduced. Temperature effect of the steel-concrete hybrid structure is calculated by FEM analysis software SAP2000 in four different supporting blocks. The structural internal force and distortion under temperature effect is analyzed. The influence of supporting blocks on the structual temperature effect is analyzed. The structural supporting block form to advantageously release its temperature effect is presented. Some advice is presented based on the analysis results.
Experimental Investigation of the Impact of Annealing on Resistivity of Boron-Doped Hydrogenated Nanocrystalline Silicon Thin Films
Authors: Pan Hai Bin , Tian Yuan , Cheng Guang Gui , Guo Li Qiang
Published: September 2010

Boron-doped hydrogenated nanocrystalline silicon (nc-Si:H) thin films were deposited by plasma enhanced chemical vapor deposition (PECVD). Microstructures of these films were characterized and analyzed by Raman spectrum and atomic force microscopy (AFM). Thickness and resistivity of these films was measured by high-resolution profilometer and four-point probe respectively. The impact of annealing on boron-doped nc-Si:H thin films’ resistivity and the relationship between resistivity and microstructure were investigated. The results show that annealing and the annealing temperature have great impact on resistivity of nc-Si:H thin films as a result of microstructures changing after annealing. Resistivity of nc-Si:H thin films decreases after annealing, but it rises with the increasing annealing temperature in the range of 250°C to 400°C.
Neural Network Analysis of the Magnetic Bearing Systems
Authors: Fu Hong Ya , Liu Ping Fan , Zhang Qing Chun , Li Guo Dong
Published: September 2010

In order to overcome the system nonlinear instability and uncertainty inherent in magnetic bearing systems, two PID neural network controllers (BP-based and GA-based) are designed and trained to emulate the operation of a complete system. Through the theoretical deduction and simulation results, the principles for the parameters choice of two neural network controllers are given. The feasibility of using the neural network to control nonlinear magnetic bearing systems with un-known dynamics is demonstrated. The robust performance and reinforcement learning capability in controlling magnetic bearing systems are compared between two PID neural network controllers.
Laser Beam Shapers Applied in the Laser Micro-Jet Processing
Authors: Lu Xi Zhao , Lin Chun , Lin Zhen Heng , Huang Yuan Qing
Published: September 2010

With respect to the methods of precise processing, the laser micro-jet system became a hot topic in recent years. In this paper, inverted Galileo telescope would reform the laser beam of Gaussian distribution into a flat-topped distribution spot, micro-jet is adopted in order to achieve a processing sharp cutter which owned the characterize of more sharp to process. It should be a reformed laser water micro-jet processing. The experiment of laser micro-jet was carried out to make reliable proof. The design of optical path integrated the Galileo shaper would reduce the pulse width under the safe circumstance. The quality of working laser beam was improved with compressing the width of flat-topped of laser beam. Laser micro-jet processing is an international patent technique which was developed by Dr. Bernold Richerzhagen in 1998[1]. During the laser processing, laser micro-jet could be used as light guide, which dues to the total internal reflection at the water-air interface [2.]
A Single-Phase Energy-Recovery Register Using Drowsy Cache and MTCMOS Techniques for Leakage Reductions
Authors: Li Hong , Zhu Jia Guo , Hu Jian Ping
Published: September 2010

With rapid technology scaling, the leakage dissipation is becoming a major source in CMOS circuits because of the increasing sub-threshold and gate leakage current in nanometer CMOS processes. This paper presents an adiabatic register file based on improved CAL (Clocked Adiabatic Logic) using MTCMOS power-gating and drowsy cache techniques to reduce both sub-threshold leakage and gate oxide leakage current dissipations. A 32 X 32 single-phase adiabatic register file are verified using HSPICE. BSIM4 model is adopted to reflect leakage currents in nanometer CMOS processes with gate oxide materials. Simulation results show that leakage losses are greatly reduced.
Design and Analysis of Agricultural Remote Monitoring System Based on ZigBee and Embedded Technology
Authors: Zou Qiu Ying , Ji Jian Wei , Zuo Zhong Shan , Zhang Su Yan
Published: September 2010

In this paper, a technical solution of remote monitoring system based on ZigBee and embedded technology are focused, designed and analyzed. This technical solution of remote monitoring system is a promising solution for the limitations of traditional agricultural information. In this work, the star form network topology based on the ZigBee was used to achieve the low-power sensor module in the agricultural field. Then such information is delivered to the remote control center through GPRS. According to the received information, the control center sends out the control command in time so that agricultural manage departments or farmers take relative measures. Therefore, costs can be reduced, and crop production can be increased.
Acoustic Measurement of a Small Sample Using Differential Acoustic Resonance Spectroscopy
Authors: Li Yao Nan , Wang Shang Xu
Published: September 2010

A new acoustic method of estimating property in rocks is presented. This method, called Differential Acoustic Resonance Spectroscopy or DARS, is based on measureing the changes in resonces of a cavity that is perturbed by the introduction of the sample. The change in the resonant frequency is used to characterize the velocity and acoustic properties of the rock sample. This article developed the numerical Differential Acoustic Resonance Spectroscopy simulation using the finite element (FE) method in COMSOL.
Dynamic Simulation of Hydraulic Truck Crane Hoisting System Based on AMESim
Authors: Fei Ye , Wu Qiong , Yu Hai Yang
Published: September 2010

This paper is made from a certain type of truck crane hydraulic lifting mechanism system as an object, then the second lifting working condition is analyzed. With AMESim, according to the hydraulic system diagram building lifting mechanism hydraulic system simulation model, hereby corresponding simulation conditions is set and the effects of secondary slide response on input signal, hoisting load, discharge and speed of pump, fluid resistance of one-way throttle is studied. This research on truck crane hoisting mechanism hydraulic system provides the theory basis for the design improvement, the relevant research methods and means have reference on the research of other engineering machinery hydraulic system working characteristics.
Research on the Power Balance of Belt Conveyor Adjusted by Hydraulic Coupler
Authors: Deng Yong Sheng , Lu Yi Gong , Xiao Ping Yang , Liu Xi Lin
Published: September 2010

Through the analysis to the working principle of hydraulic coupler and the combining operating characteristic of motor with hydraulic coupler, the principle for adjusting the power balance of motor by hydraulic coupler was obtained; and the merits applying the hydraulic coupler in the belt conveyor driving system were summarized. Taking the forehead double-drum driving system as the example, and using the formula of the power unbalancedness for double-drum transmission, the power unbalancedness of motor before and behind the motor with hydraulic coupler was extracted. The analysis result indicates that the effect improving the power balance for the belt conveyor by hydraulic coupler is extremely obvious.
The Damage Theory Model on Fluid-Solid-Heat Coupling of Reservoir under Process Injection
Authors: Zhao Wan Chun , Ai Chi , Zheng Da Chun
Published: September 2010

Based on the study of double porous medium, the paper provides a new model of cylinder volume element plastic yielding, which assumes that the rock mass is compressible and obeys the D-P formula, and deformation, nucleation and growing of pores and fractures are induced by stress of injection pressure and temperature. The damage variable is defined by strain porosity, and then constitutional equation of double pore medium saturated liquid-solid is set up. Taking one well of Jilin Oil Field in China as a case, the damage variable, porosity and induced stress change laws of rock strain coupling with temperature-injection are studied. The results are acquired from numerical simulation of finite element software, including induced stresses of thermal field, water flood pressure, rock stress distribution rule, together with evolving regulations of stress, damage variable and strain porosity. The numerical computation results match well with the practical situation, which shows that there is obvious elastic and plastic damage characteristic during mass water flood recovery. The new model provides a new research method and theoretical base for changes of reservoir pores and fractures during water flood exploration.
The Reliability Study of LRB Continuous Girder Bridges Subject to Seismic Excitation
Authors: Liu Wen Jing , Li Li , Ye Kun
Published: September 2010

LRB base isolation technology is different from the traditional continuous girder structure system, and shows good isolation performances. However, because fixed piers were canceled and all bearings were LRB, it is often considered that the reliability of structure might be reduced. Therefore, the reliability of LRB continuous girder bridges subject to seismic excitation was systematically studied from different indicators for the first time in this paper, the world's first double traffic double deck isolated continuous girder bridge – Dongjiang double-layer-pier isolated approach bridge in Dongguan of Guangdong province was adopted as study case. The results shows that, when the effect of pile-soil interaction is considered, LRB system still has a very good isolation performance; pounding subjected to seismic must be analyzed; dynamic stability needs checking when higher piers and larger earthquake displacement. Generally speaking, the reliability of LRB continuous girder bridges subject to seismic excitation won’t be reduced.
Nonlinear Behavior of Pedestal Looseness Fault Rotor-Bearing System with Slowly Varying Mass
Authors: Luo Yue Gang , Zhang Song He , Wu Bin , Wen Bang Chun
Published: September 2010

The dynamic model of the pedestal looseness fault rotor-bearing system with slowly varying mass was set up. The complex characteristics of the rotor-bearing system were numerically studied. Along with the increase of the looseness mass, the chaotic motion area and amplitude range increase in the region of critical rotating speed; and P-3 motion area disappears in the region of twice-critical rotating speed, chaos is the main motion form. Along with the increase of the coefficient of mass slowly varying amplitude, the instable rotating speed increase, and the chaotic motion area decreases, P-n motion area increases in the region of critical rotating speed and twice-critical rotating speed. The conclusions may provide basis reference for fault diagnosis.
Research on Fuzzy Control of the Hydraulic System for Continuously Variable Transmission
Authors: Wang Chang Zhou , Song Jin Chun , Li Song
Published: September 2010

Velocity ratio control is one of the key techniques of vehicle metal V-belt type CVT. In this paper, the working principle and hydraulic control system principle of the metal V-belt type CVT were introduced; the mathematic model and fuzzy self-adaptation PID control model of the velocity ratio electrohydraulic proportional control system were established and simulated. It was found that, fuzzy self-adaptation PID control system makes actual velocity ratio change as it was expected with good steady-state characteristics and dynamic response characteristics.
Grey Evaluation Method on Security Risk Assessment of Power Information System
Authors: Liu Ren , Niu Dong Xiao
Published: September 2010

As information technology is widely used in electric power field, security risks penetrate into all aspects of electricity production and operation, meanwhile, complexity of electric power information system make it's very difficult to guard against security risk. Information security risk assessment is the foundation and the precondition of information system security. In this paper, combining long-term power information security supervision practice, we give a multi - hierarchy and multi - attribute index system of information security risk evaluation, and point out these indexes are characterized with grey, fuzzy and difficult to quantify. Then, the analytic hierarchy process (AHP) and the theory of grey system are introduced in setting up a comprehensive evaluation model, we obtain the final score using the information fusion of different experts. Additionally, an application example is used to illustrate the availability of the proposed evaluation method. The result shows that grey evaluation which combines advantages of the qualitative and quantitative methods can be applied to risk evaluate of information system more accurately and scientifically. Meanwhile the evaluation results can help supervisors judge which is the necessity to improve.
Research on Control Strategy of Maximum Power Point Tracking of VSCF Wind Generation
Authors: Dai Wen Jin , Liu Hai Jing
Published: September 2010

Variable speed constant frequency wind turbines can get the maximum power by adjusting the rotor speed of the induction generator according to the variable wind speed. The mathematical relationship between wind speed of wind generation and power of wind turbine power is studied in this paper, then control strategy of maximum power point tracking consists of comparative law of the greatest power, table look-up scheme of the best tip speed ratio and a variable step mountain climb algorithm and the like., and advantages and drawbacks of them are compared. Finally a variable step mountain climb algorithm for an induction generator is studied and the wind turbine model is tested by MATLAB simulation. System simulation results have confirmed the functionality and performance of this method.
Research on Induction Motor DTC System Based on Fuzzy PI Controller
Authors: Hu Xue Zhi , Nan Guang Qun
Published: September 2010

Traditional induction motor direct torque control system with the hysteresis loop controller, based on torque error, set the amplitude error to select the inverter switching state, is a Band-Band Control , torque error and stator flux error of level can not be distinguished, switching frequency is not constant, over-sector current and the distortion flux linkage can product low speed torque ripple, affecting the control of the system effect. The paper proposed fuzzy PI control of induction motor direct torque control scheme, a system of principles was introduced, controller parameters was designed by fuzzy theoretical. Finally a full-digital experimental system was built with the TMS320F2812 as the master chip and PM30CSJ060 as an inverter main circuit. Results show that the dynamic and static performance and running smoothly with low-speed is verified.
Collaboration Strategy Simulation of Multi-Agents for Pursuit-Evasion in Wireless Sensor Networks
Authors: Guo Li Xin , Zhao Lei Ping
Published: September 2010

In this study, we used Cricket equipments based on wireless sensor networks to study the pursuit-evasion strategy of multi-robots in a continuous map. In order to improve the efficiency, two new pursuit-evasion strategies were proposed. To meet the need of a continuous map, a greedy algorithm was utilized to deal with boundary problem when a pursuer or an evader was near the field boundary. The statistical results show the converging-attack pursuit strategy outperforms in pursuing the evader with different escaping strategies, such as randomly moving, active escaping strategy and vector-wards escaping strategy. The vector-wards escaping strategy is also effective in delaying the capture of evaders.
The Design of the Electro-Hydraulic Speed Control System for Diesel Engine
Authors: Jia Liang Mian , Wang Gang , Zhi Xiao Hui
Published: September 2010

The design of a newly developed electro-hydraulic speed control system for diesel engines was presented in this paper. Its general scheme design, actuator design and electronic control unit design were introduced. In the system, the rack position of the fuel injection pump was adjusted by a rack actuator and the fuel supply quantity of the fuel injection pump is adjusted. The system maintained the steady speed control of the diesel engines, enhanced the engine power usage, and reduced the fuel consumption.
Study on Parameter Optimization Based on Workspace of 3-DOF Parallel Machine Tool
Authors: Li Xing Shan , Cai Guang Qi
Published: September 2010

This paper proposes an optimization method which makes the structural parameters are minimum and the workspace is maximum based on 3-DOF parallel machine tool. By analysis the conditions of boundary, parameters optimization model is built and gives out the explicit solution of dexterous workspace. Analysis the effect of structural parameters on workspace. The results show the workspace is a unsingularity space.
Dual Extended Kalman Filter Based Momentum Wheel Identification
Authors: Li Zhi Zhou , Zhang Rui , Zhu Zhen Cai , Liang Xu Wen
Published: September 2010

As the most important actuator of the attitude control subsystem of the spacecraft, the momentum wheel should be precisely simulated. In this paper, Dual Extended Kalman filter is expressed and used to identify the momentum wheel system. In this way, the identification result can be used in the momentum wheel system simulation. This makes simulations run both fast and precisely. The numerical simulation results show that the algorithm can converge in given error.
Research on the Design of Motion Control System Based on a Novel 5-DOF PCMM
Authors: Chen Xiu Long , Hu Gang , Jiang Xue Yan , Wei De Yong , Zhao Yong Sheng
Published: September 2010

A novel 5-Degree of Freedom PCMM (parallel coordinate measuring machine) was proposed, and its motion control system was designed. Compared with the other structural PCMMs, the structure feature of proposed PCMM was described. Then its motion control system was designed with the modularized and open architecture. The controlled scheme of hardware, which based on PC, PMAC motion control card and the precision measuring probe, was developed. The software of the motion control system was written by Visual Basic6.0 language. Finally, the process of motion control for 4-UPS-UPU PCMM was proposed. The new method above for design of motion control system is simple and effective, and may be applied to other parallel machine.
Low Cost AFDX End System Based on System on a Programmable Chip
Authors: Yu Bing , Zhang Tian Hong , Liu Dong Dong
Published: September 2010

AFDX (Avionics Full DupleX Switched Ethernet, ARINC 664) utilized in Airbus A380 and Boeing 787 represents a major upgrade in both bandwidth and capability; however some legacy systems are difficult to connect into the AFDX bus smoothly. A low cost AFDX end system based on SOPC (System On a Programmable Chip) is presented. A Xilinx Spartan 3AN FPGA is employed to build the whole system; and then a dedicated reduced Ethernet MAC controller for AFDX end system is designed; a MC8051 open core microcontroller is employed as the system controller and protocol processing unit. The whole design costs small FPGA resources and the experiments show that the designed AFDX end system works robustly and correctly.
Manufacture Parameter Design of SMG Spiral Bevel Gears Based on Local Synthesis and Transmission Error Optimization
Authors: Liu Guang Lei , Fan Hong Wei , Jiang Ping
Published: September 2010

An optimization approach for manufacture parameter design of the SGM spiral bevel gears with modified tooth geometry is proposed. The approach is accomplished by application of local synthesis, tooth contact analysis (TCA) and dual-objective optimization of transmission error function. A computer program to obtain a set of manufacture parameters based on the proposed theory is developed and illustrated with an example. The proposed method provides a set of machine-tool settings for pinion NC-grinding which ensures: (i) a localized bearing contact pattern less sensitive to misalignments, (ii) a parabolic transmission error function to reduce vibration and noise in mesh.
Study of a Bistable Stochastic Resonance-Based Children Activities Monitoring System Using Wireless Sensor Network
Authors: Hui Guo Hua
Published: September 2010

Children heart rate monitoring plays an important role among human health research field. In this paper, a synchronized intelligent sensor network was designed for children heart rate monitoring. The ECG sensor, MMA7261QT accelerometer sensor and CSR BC4 Bluetooth module were accepted for heart rate monitoring. The experimental data features were extracted by the bistable stochastic resonance data processing method. The signal-to-noise ratio (SNR) maximum value was used to judge the children action state. The experimental results showed that the designed system provided an effective method for a big scale children health monitoring.
The Technological Optimization of Closed Multiple-Ram Forging for Draw Rod
Authors: Zhu Chun Dong , Dai Tai Liang , Wang Hui
Published: September 2010

Draw rod is one of the main mechanical parts of vehicle steering system，which is required extremely high quality. At present the way to produce the draw rod is machining after common open-die forging. This technology will produce big flashings，damage the metal’s fibrous structure and reduce the material utilization. In this essay, we will use the technology of closed multiple-ram forging to produce it. We will utilize numerical simulation on several blanks through numerical simulation combined with experiments. In this way, the defects that some parts of the blank are folded and cannot fill well during forming process can be effectively avoided. Besides, there will be free of flashing and the draw rod forgings do not need to be cut. The weight of the original blank will be about 3.5 kg after being optimized, down by 36.4 percent compared with that of original material about 5.5 kg. And we will make different settings for the loading way of the plunger chips during the forming process, then compare with the simulation results and ultimately find out the best loading way. At last, we will verify the feasibility of such an optimal technology through experiments on the material-lead.
The Study on the Strategy of Bidding Project Selection Based on Fuzzy AHP in Network-Based Manufacturing
Authors: Zhang Xian
Published: September 2010

Enterprise alliance is a basic organization which achieves network-based manufacturing. One of the key factors which affect the enterprise alliance’s buildup is that the candidate enterprise can make a correct decision in the selection of a cooperative project. This paper proposes a fuzzy AHP model to select the bid projects made by the leaguers to be selected basing on the analysis of the inportance of these bid projects. This model provides a comprehensive consideration for the various evaluation factors affecting the selection of a bid project. According to this model, candidate enterprise can select a bid project correctly.
Atmospheric Correction of Landsat ETM+ Remote Sensing Data Using 6S Code and its Validation
Authors: Yang Xiao Feng , Wen Xing Ping
Published: September 2010

Atmospheric correction is one of the most important pre-processing steps in quantitative remote sensing. To extract quantitative information from the Enhanced Thematic Mapper-Plus (ETM+) imagery accurately, atmospheric correction is a necessary step. Furthermore, multi-temporal images after atmospheric correction can be compared to each other quantitatively. The Second simulation of satellite signal in the solar spectrum (6S) radiative code can process many types of satellite data and provide several standard atmosphere and aerosol models for atmospheric correction. This paper demonstrates atmospheric correction of Landsat ETM+ data using 6S code. Comparing images before and after atmospheric correction, the different of image before and after correction was not obvious using visual interpretation. Therefore, different ground object spectral curves after atmospheric correction are illustrated. They were similar with the standard ground object spectra. The correlation coefficient of ETM+ band 1 to band 4 and NDVI (Normalized Difference Vegetation Index) after atmospheric correction increases. The atmospheric correction removed the atmosphere effect, so the inherent relevant increased. 6S code was an effective tool for atmospheric correction of remote senisng data.
Design of Embedded Remote Monitoring Terminal Based on 3G Module SIM4100
Authors: Yu Hong Bo , Tao Bai Rui , Zhu Heng Jun , Li Hui
Published: September 2010

This article presents a remote image monitoring System based on TD_SCDMA technology. This system takes Samsung’s S3C2440 as the processor and the LCD touch screen as the interface. It runs the Linux operating system and captures image information through the front camera. After dealing with image compression by the video capture and compression card, the SIM4100 module carries on the real-time transmission via 3G network, so as to achieve the purpose of remote image monitoring.
Architecture Design of Distributed Computing System Based on SOA Model
Authors: Li Ji Chu , Jin Hui Xia , Tang Jun
Published: September 2010

With the sharp increase of data amount in modern computing process, it needs more powerful general computing ability to process and compute data. Web Services--based Distributed Universal Computing Platform (WSDCP) provides an inexpensive solution for large-scale computing tasks in a loosely coupled manner with high flexibility and node autonomy. System adopts Web Services, XML as technical support, through installation of intelligent probe on nodes to real-time collect the situation of node, and the disequilibrium task allocation and dynamical task regulation can improve system reliability. WSDCP system takes green computing concept as guiding concept, and takes advantage of idle CPU resources on the Internet, which have positive significant for establishing resource-conserving society.
Study on Emergency Evacuation Ability of Exits in Public Assembly Places
Authors: Dai Bao Qian , Wang Tong , Zhang Jin
Published: September 2010

The state of pedestrian flow was observed for public assembly place exit. The basic parameter data of evacuation simulation obtained from the experiment. A compared result of evacuation experiment of special scene and evacuation simulation revised model parameters. Revised model simulated pedestrian evacuation was carried out in typical public assembly place. Research results of this paper provide scientific basis for exit design, risk analysis and emergency management.
Investigation of the Disk Cavitator Cavitating Flow Characteristics under Relatively High Cavitation Number
Authors: Hu Xiao , Gao Ye
Published: September 2010

Simulations on two-phase cavitating flows containing water and vapor, on axisymmetric body with disk cavitator have been implemented through the cavitation model in Fluent 6.2, the flow field around cavitator under different incoming conditions is studied respectively, and analyses to parameters pertinent to cavity including dimension, streamlines, vapor volume fractions and pressure distributions along the body surface are given when the incoming cavitation number ranges from 0.3 to 0.8, the results show that the vapor volume fraction and threshold phase-change pressure within the cavity under the same cavitation number gradually ascends as the Reynolds number increases ; the effects of incoming pressure on threshold phase-change pressure inside the cavity is insignificant.
Algorithm for Automatic 3-D Scanned Bullet Identification Based on the Principle of Human Vision
Authors: Lu Jing , Wu Shi Hong , Shi Yu Da
Published: September 2010

Bullet identification is a complicated work which demands high accuracy rate. In this paper, we try to find a reliable and fast automatic bullet identification algorithm using image processing technology. The key and most difficult step is to find an image feature which can describe the unique striation pattern on the bullet. When we do bullet identification by human-eye, we try to best match the striations of the bullets. It’s mainly according to the order of the striations and the distance between them. Based on this principle, a new algorithm for automatic bullet identification is proposed. Using the bullet’s visual graphic set which is offered by the Three-Dimensional Laser Color Scanner (3DLCS), we firstly do pre-processing to the bullet unwrapped image, such as image enhancement, edge detecting, binarization, thinning and denoising, to obtain an image with clear striations and low noises. Then we find an effective image feature based on the principle of human vision: the bullet feature vectors (BFVs). According to actual needs, we give a reasonable definition for vector distance (VD) between vectors of different dimensions, and take VD of BFVs as a measurement for bullet similarity. Experimental results prove that our algorithm can correctly find the bullets with high trace similarity and do bullet identification successfully.
Numerical Simulation on Flow Past Sphere-Conic with Ablation
Authors: Huang Hai Ming , Xu Xiao Liang , Liu Yu
Published: September 2010

A combined numerical model is proposed in order to solve ablation and denudation under high temperature and high pressure. Vortex method is used for simulating vorticity field and pressure distribution; a three-equation model is used for resolving the ablation mass loss; and a trajectory model is adopted for solving the motion of denudated particles. Compared with the flow past an ablating cylinder with the same Re number and ablation condition, the ablation effect on the sphere-conic is more significant and the vorticity contour turned to an asymmetric structure earlier; the particle traces are no longer symmetric, and the particles distribution become unorganized; the linear momentum of the ablating sphere-conic become larger than the non-ablating one; This simulation may offer numerical references to ablation experiments on thermal protection materials.
A Novel Method of Stereo Camera Calibration Using BP Neural Network
Authors: Xiong Jiu Long , Xia Jun Ying , Xu Xian Quan , Tian Zhen
Published: September 2010

Camera calibration establishes the relationship between 2D coordinates in the image and 3D coordinates in the 3D world. BP neural network can model non-linear relationship, and therefore was used for calibrating camera by avoiding the non-linear factors of the camera in this paper. The calibration results are compared with the results of Tsai’s two stage method. The comparison show that calibration method based BP neural network improved the calibration accuracy.
Attribute Recognition Model Based on Entropy Weight and Its Application to Evaluation of Groundwater Quality
Authors: Zhang Xian Qi , Feng Wen Hong , Li Nan Nan
Published: September 2010

It is necessary to take into account synthetically attribute of every index because of independence and incompatibility resulted from single index evaluating outcomes. Through the information entropy theory and attribute recognition model being combined together, attribute recognition model based on entropy weight is constructed and applied to evaluating groundwater quality by a new method, weight coefficient by the law of entropy value is exercised so that it is more objective. The outcome from concrete application indicates that it is suitable to evaluate water quality with reasonable conclusion and simple calculation.
A Study on the Impact of Industrial Concentration on the Economic Growth Based on the Analysis of Gini Coefficient of the Construction Regions
Authors: Zheng Xiao , Liu Zhen Ning
Published: September 2010

This paper reveals the concentration status of the construction industry in the 8 provinces of southeast China, its impact on the local communities, and proposes a tentative plan to stimulate local economy through industrial concentration based on the measurement and calculation of Gini coefficient in the 8 provinces and regression analysis of their population and output of steel and concrete.
A Modified Two-Way Authentication Protocol without Server for RFID
Authors: Lu Xin Mei , He Lei
Published: September 2010

It is necessary for researchers to design lightweight authentication protocols to protect information security between tag and reader in RFID system. It is a great challenge to design an efficient and secure protocol because the tag has limited computation resource. In the paper, we firstly analyze some protocols. Secondly, we introduce a serverless authentication protocol for RFID system and analyze its security. We find it does not provide two-way authentication. Thirdly, we propose a modified two-way authentication protocol without server for RFID. The result indicates it provides privacy protection, resists tracking, and resists cloning attack. Moreover, it provides two-way authentication. For the efficiency, we think the computational complexity of our protocol is at the same level with the original protocol.
Experiment Study of Volatilization Combustion during Coalfield Fire
Authors: Qu Zhi Ming
Published: September 2010

Experiment is a more direct and reliable way, through which the observation and data analysis can summarize specific qualitative and quantitative relationships and the fire mechanism and laws phenomenon. It can provide a reliable basis for the proposed theory or computational model from the general principle and validation for the theory or the results. Through experiment, heating process takes greatest impact on the heating surface but least on inner parts. While the temperature is ascent to some degree, the heating surface temperature will exceed the temperature and continue to be ascent, which indicates that the coal begins to oxide. While the airflow is increased, the temperature will be slightly increased. The temperature is descent more slightly in the coal temperature because of thermal radiation.
Study on Three-Dimensional Large Eddy Simulation during Train Fire
Authors: Qu Zhi Ming
Published: September 2010

The train fire has been greatly focused by fire researchers all over the world, the key to which is the study of smoke flow. The simulation model is set up to analyze the concentration and the temperature of smoke flow during the train carriage fire. The concentration and temperature is very high near the fire in the closed space. Meanwhile, the spreading speed of smoke flow will be accelerated when the doors are open. The concentration of smoke near the fire will be decreased. The simulation shows that the fire should be extinguished at the initial stage. After being developed because of the pouring of fresh air, the smoke concentration and the temporary ventilation should be controlled.
Fuzzy Neural Network for Groundwater Level Prediction
Authors: Zhao Wei Guo , Wang Li Ying
Published: September 2010

In this paper, prediction system is developed based on a fuzzy neural network(FNN) by using the past groundwater level data to discover fuzzy rules and make future predictions. The learning algorithm is implemented to the past historical data. Compared to other predictors, our results show that the FNN predictor can reduce significantly both relative mean errors and root mean squared errors of predicted groundwater level. It is demonstrated that FNN performs well for groundwater data analysis and its feasibility of applying FNN to groundwater level prediction.
Daily Discharge Prediction Using Artificial Neural Networks
Authors: Zhao Wei Guo , Wang Li Ying
Published: September 2010

A daily discharge prediction system is developed by the Artificial Neural Networks (ANN) using real daily discharge data, ANN have great generalization ability and guarantee global minima for given training data. In the paper, with 8 years long-term daily information, the ANN can construct a very high precision daily discharge forecasting system. The experiment shows that the predicted curve well regresses the observed curve. It can be concluded that this technique can be seen as a very promising option to solve nonlinear regression.