bluuebunny/crossref_metadata_2025 huggingface dataset:
Long Term Reliability and Power Degradation Analysis of Multicrystalline Silicon Solar Modules Using Electroluminescence Technique
Authors: Lin Keh Moh , Lee Yang Hsien , Huang Wen Yeong , Kuo Yi Wen , Wang Li Kuo , Yang Sian Yi
Published: September 2012

In this study, the quality degradation of multi-crystalline silicon photovoltaic (PV) modules during the aging process was observed by using electroluminescence (EL) technology and IV curve measurements in order to find out the occurring timing of damages on solar cells. The influences of soldering materials and temperatures on the performance of the PV modules were also studied. Experimental data show that, high soldering temperatures which induce high thermal stress can easily lead to the power loss of the PV modules. On PV modules soldered with SnAgPb (SAP) solder, ca. 40% of module damages occurred after 25 cycles during the thermal cycling (TC) test. In contrast, there were 61.5% of damaged SnPb (SP) modules after the 25 TC. Most module damages which are attributed to the crack growth and the floating solder emerged during the soldering and encapsulation processes. In our experiment, the average power degradation of all modules was less than 10%.
Research on Obstacle Performance of Micro Battlefield Robot
Authors: Yu Qiu Shui , Tang Haoang , Tian Ya Nan
Published: September 2012

In several typical battlefield terrains, this paper analyzed the obstacle performance of the micro battlefield robot (MBR)and found out the major parameters. After tested with a prototype robot for many times, the analysis is proved right.
The Research and Practice of Fast Handoff Scheme Base on V2V
Authors: Zhang Yun Peng
Published: September 2012

In VANETs, each vehicle should obtain an IP address for its identification before connecting to the Internet or getting some information from the Internet. Due to the rapid movement of vehicles, each vehicle must perform a handoff procedure between different access points. To ensure that the transmission of packets is not interrupted, the handoff scheme for VANETs is a key design issue. In view of this, we design a V2V-based fast handoff scheme using IP address passing for VANETs in this thesis.
Study on the Conductive Filament Formation of HfO2
Authors: Wu Xiu Long , Zhou Mao Xiu
Published: September 2012

The conductive path formed by the interstitial Ag or substitutional Ag in HfO2 was investigated by the Vienna ab initio. The calculated results indicated that the ordering of interstitial Ag increases the conductivity of HfO2 by forming a conductive filament. The contribution to the electrical conductivity of Ag ions in the material of HfO2 was investigated.
A Grinding Protocol for the Fabrication of Micro/Meso Aspheric Moulds for Optic Applications
Authors: Huang Han
Published: September 2012

This paper summarised our recent results on the development of grinding technologies for the fabrication of aspheric components at micro/meso scales made of cemented tungsten carbide. Based on these results, a grinding protocol was proposed for the fabrication of aspheric moulds. The protocol includes the understanding of deformation and removal mechanisms of hard and brittle materials involved in grinding, the preparation of grinding wheels, the compensation of profiling errors and the optimisation of the grinding process.
Research on Functional Surface Grinding of Medical Titanium Plate
Authors: Wang Wan Shan , Zhang Bao Gang , Zhao Hai Feng , Wang Wei , Li Hu
Published: September 2012

Medical titanium plates with smooth surface will be long-standing in body under the condition of free state when it used for bone fixation. To solve this problem, function-surface titanium plates with a certain roughness and shape must be grinded. So ceramic CBN abrasion wheel is used to grind titanium alloy in CNC machining tool and the status of force, heat and vibration in the grinding process will be monitored in the same time. The surface morphology which can meet the growth of tissue could be obtained in a certain technological conditions by observing the grinded surface with super depth of field microscopy devices.
Three Dimensional Analysis of a Grinding Wheel Surface with Image Processing
Authors: Sakaguchi Akihiro , Kawashita Tomoyuki , Matsuo Shuji
Published: September 2012

It is very important to measure a grinding wheel surface topography. Therefore a three dimensional measurement system of grinding wheel surface with image processing has been proposed. This system can evaluate a variety of the wheel surface topographies. For example, a histogram of the area or the shape of cutting edges and the distribution map of every shape of cutting edges were obtained. In this paper, a three dimensional model of the cutting edges and a correlation between the state of the wheel surface and grinding mark on the workpiece are reported and the effectiveness is evaluated through an experiment.
Thermo-Chemical Dressing of Coarse Grained Diamond Grinding Wheels
Authors: Riemer Oltmann , Mutlugünes Yildirim
Published: September 2012

This paper deals with a novel dressing method for coarse grained, single layered metal bonded grinding wheels based on the dynamic friction polishing. The diamond friction polishing technique utilizes the thermo-chemical reaction between a diamond sample and a metal tool rotating at high speed. Here, the tips of the diamond grains of a rapidly rotating grinding wheel are thermo-chemically flattened due to the contact with two slowly rotating steel calottes at predetermined friction pressure pd and grinding wheel velocity vsd. Dressing experiments have been carried out changing the friction pressure pd and the grinding wheel velocity vsd. The generated topography of the grinding wheel has been characterized by a confocal laser scanning microscope. Thus, the flattened grains with an average grain protrusion hk could be measured and the influence of the friction pressure and grinding wheel velocity on the dressing process is shown.
Study on Grinding Processing of Sapphire Wafer
Authors: Ebina Yutaro , Hang Wei , Zhou Li Bo , Shimizu Jun , Onuki Teppei , Ojima Hirotaka , Tashiro Yoshiaki
Published: September 2012

This paper reports our recent results on the diamond grinding process of single crystallized sapphire wafers. It was found that the diamond grains were severely dislodged at the wheel/ workpiece interface and the material was removed by a mixed process of both grinding and lapping. Grinding governed the wafer center while lapping dominated its fringe. By increasing the wheel speed, it was able to shift the dominant process from lapping to grinding, and achieve a better surface roughness. Nine diamond wheels varying in both concentration and bond material were tested in surface grinding of 6 inch sapphire wafer, to investigate the dynamic behavior of diamond grain in the grinding process and its resultant surface quality and productivity.
Visualization of Grinding Wheel Surface Topography for Multiple Passes of Rotary Diamond Dresser
Authors: Chowdhury M.A.K. , Tamaki Jun’ichi , Kubo Akihiko , Ullah A.M.M. Sharif
Published: September 2012

The grinding wheel surface topography after dressing is an indicator of the effectiveness of dressing operation and, thereby, the effectiveness of grinding as a whole. During dressing, the dresser travels the grinding wheel surface several times so that the dresser grits could hit all most all points on the circumference of the grinding wheel. But the same point should not be hit several times by the dressing grits. This study describes a method and tool for visualizing the grinding wheel surface topography for multiple passes of rotary diamond dresser. Using the proposed visualization method and tool, one can determine the effectiveness of certain dressing conditions beforehand. In addition, the visualization tool can be used for optimizing the design variables of a rotary diamond dresser.
Ultrasonic Vibration Assisted Mechanical Chemical Polishing (MCP) of Silicon Carbide
Authors: Liao Yunn Shiuan , Yu Y.P. , Huang C.W.
Published: September 2012

The mechanical chemical polishing (MCP) process which uses soft abrasives to polish hard workpiece have been employed recently to polish silicon carbide (SiC) ceramic for various applications. An ultrasonic vibration assisted apparatus is designed to investigate the effects of ultrasonic vibration on the efficiency of MCP of SiC by ferric oxide (Fe2O3) abrasives. Experimental results show that the ultrasonic vibration can effectively improve polishing efficiency; the material removal rate is increased by about 60~70%. But it does not lead to a better final surface finish. The effect is more obvious under a higher working pressure condition. It is also found that the output power of ultrasonic transducer is positively correlated with material removal rate. The rise of polishing efficiency is attributed to the increase of local asperities temperatures which promote chemical reaction of silicon carbide with oxygen to form passivation layers. The layers are removed by ferric oxide abrasives afterward.
Parameters Optimization on the Lapping Process with Porous Self-Generation Superabrasive Tool by Applying Taguchi Method
Authors: Lv Bing Hai , Wu Zhe , Yuan Ju Long , Deng Qian Fa , Zhao Ping
Published: September 2012

Porous self-generation superabrasive tool (PSST) is a newly developed metal bonded superabrasive tool. It is found that processing parameters have great influence on the machining quality when using PSST. This paper focuses on the application of Taguchi method for optimization of lapping process parameters when using PSST to obtain the best surface quality. An optimization experiment for lapping optical glass with PSST was designed by Taguchi method. Surface roughness Ra is considered as criteria for optimization. Influence of parameters involving filler concentration in binder, lapping load, lapping speed and concentration of solute are discussed, and the optimum lapping condition is figured out. The optimization result illustrates that the experiment design based on Taguchi method can successfully applied to determine the optimum processing conditions for lapping process using PSST.
Vibratory Finishing of Immobilized Cylinders
Authors: Wan Stephen , Sato Takashi , Hartawan Andry
Published: September 2012

We report preliminary results from an on-going study investigating the effect of fixing workpieces within the media flow field contained in a typical vibratory finishing bowl. To this end, we studied the surface roughness evolution over the surfaces of workpieces with generic geometries such as cylinders. A granular flow dynamics model applicable to dense granular flow and a previously derived process equation were invoked in order to respectively describe the flow of the abrasive media; and the roughness distribution in terms of the granular pressure and velocity. By solving the granular flow field for the pressure and velocity distribution on a given geometry using a general purpose computational fluid dynamics (CFD) code, we were able to analyse changes in surface roughness distribution from the process equation. The immobilized cylinders were submerged in the top portion of the media flow field so as to facilitate comparison between media flow past the workpieces as experimentally observed and as predicted by the CFD simulations. We conclude with an analysis, based on both experimental and predicted results, of the way in which media flow direction biases the surface roughness distribution on an immobilized cylinder.
A Framework for the Analysis of Mass Finishing Processes
Authors: Wan Stephen
Published: September 2012

The aim of this paper is to introduce, in broad strokes, a framework – constructed from a fusion of granular flow (GFD) dynamics, tribology and computational fluid dynamic (CFD) techniques – for the practical analysis of mass finishing processes. The presentation opens with a short introduction to typical mass finishing processes, followed by a brief discussion on their respective correspondences to GFD regimes, and ends which some illustrative results arising from the application of this framework to vibratory finishing, which is perhaps the most industrially pervasive mass finishing process.
Effect of Fabrication Conditions on Ultra-Fine Abrasive Polishing Pad
Authors: Zhang Yun He , Lu Jing , Huang Hui , Xu Xi Peng
Published: September 2012

Considering the grit aggregation of fixed abrasive and the environmental pollution of free abrasive machining tools, a kind of ultra-fine abrasive polishing pad was fabricated by means of sol-gel technology. The effects of drying method, gel reaction time, sodium alginate concentration and pad thickness which determine the property of the polishing pad were respectively investigated. And the polishing pad fabricated under the optimized condition was utilized to polish silicon wafer on a nano-polishing machine to evaluate the tool performance.
Effect of Ground Surface Roughness of Ball End Mill on Cutting Characteristics
Authors: Furuno Masahiro , Kitajima Koichi , Akamatsu Takeshi
Published: September 2012

The results of an investigation on the effects of surface roughness on ball end mill are reported here. We used grindwheels with varying in grit between #325 and #1000 to grind ball end mill’s rake surface and flank surface, and then coated the end mill with TiAlN film, CrSiN film, and TiSiN film. We measured the state of adhesion on the films on the rake surface in continuous lathe milling as well as the surface roughness and cutting force. The results show that, in generating the cutting cutoff, the optimum grinding roughness differs between the near vicinity of the cutting-edge ridgeline and the part of the rake surface that is further away from the cutting-edge ridgeline. From that fact, we understand that the cutting characteristics of the work material and the surface area of the rake surface that is in contact with the cutting cutoff exert their respective influences during the cutting.
Finish Cutting of Carbide Mold with Thermally Affected Layer by Diamond Tool
Authors: Imazato Kazuki , Okuda Koichi , Shizuka Hiroo , Nunobiki Masayuki
Published: September 2012

This paper deals with finish cutting of thermally affected layer on cemented carbide by a diamond tool in order to machine efficiently the carbide mold with high accuracy and good surface without a polishing. The microstructure of thermally affected layer left by EDM process was observed and analyzed by EPMA. Its hardness and thickness were measured. Subsequently, the cutting experiments were carried out by using a PCD tool and an ultra-precision cutting machine. The effects of the thermally affected layer on the surface roughness, the cutting force and the tool wear were investigated. As a result, it was confirmed that the cutting force decreased with an increase in the depth of cut. Furthermore, it was found that the tool wear and the surface roughness obtained by cutting the thermally affected layer were greater than those of the original workpiece.
The Effects of Resharpening Accuracy on Drill Failure and Hole Straightness in High Aspect Ratio Gundrilling of Inconel-718
Authors: Woon Keng Soon , Kanno Shigeyuki , Liu Kui
Published: September 2012

This paper presents a pilot study on the consistency of high aspect ratio gundrilling of Inconel-718 that involves the drilling of three holes of 8mm in diameter and 1600mm in depth, under constant drilling conditions. But high degree of straightness variations among these holes indicates that critical drill geometries could not be accurately regenerated through the drill resharpening operation. As a result, vast variability is introduced to the process which has severe detrimental effects on the stability of the drilling process and degradation and failure modes of the drill as well the straightness accuracy of the holes.
Study on the Combined Machining Technology of Sawing and Grinding for Drilling Aramid/Epoxy Composites
Authors: Gao Hang , Zhuang Yuan , Wang Ben , Huang Jun Liang
Published: September 2012

Aiming at the problem of poor machinability in conventional drilling of aramid/epoxy composites, the formation reason for fuzzing damage was analyzed. In order to obtain better machining quality, a combined machining technology based on sawing and grinding mechanism was proposed and the corresponding drilling tools were developed. Drilling experiments were conducted to explain the machining performance of the drilling tools. The results show that the sawing drilling tool with negative rake angle can effectively restrain fuzzing damage and the sawing-grinding drilling tool decreases the thrust force about 20%~55% with electroplated diamond abrasives. The combined machining technology of sawing and grinding achieves damage-free machining quality in drilling of aramid/epoxy composites.
Porous Composite-Bonded CBN Grinding Wheel with Alumina Bubbles
Authors: Chen Z.Z. , Ding Wen Feng , Xu Jiu Hua , Song C.J. , Fu Y.C. , Yang C.Y.
Published: September 2012

Fabrication experiments of porous composite-bonded CBN wheels were conducted using alumina (Al2O3) bubbles, CBN grains, Cu-Sn-Ti alloy and graphite particles. Influence of sintering parameters and porosity on the bending strength of the CBN composite blocks was measured and analyzed. Dressing and grinding practice was carried out. The results show that the optimal sintering temperature of the CBN composite blocks is 880°C. When the porosity of composite blocks is 8-45 %, the strength reaches 51-103 MPa. Regular shape of the pores is obtained after dressing. Both the grinding force and grinding temperature of the composite-bonded CBN wheel are lower than that of the vitrified one under the same grinding condition, which indicates the better grinding performance of the new-type porous composite-bonded CBN wheel.
An End-Milling Condition Decision Support System Using Data-Mining for Difficult-to-Cut Materials
Authors: Kodama Hiroyuki , Shindou Masatoshi , Hirogaki Toshiki , Aoyama Eiichi , Ogawa Keiji
Published: September 2012

We proposed the data-mining methods using hierarchical and non-hierarchical clustering methods to help engineers decide appropriate end-milling conditions. The aim of our research is to construct a system that uses clustering techniques and tool catalog data to support the decision of end-milling conditions for difficult-to-cut materials. We used variable cluster analysis and the K-means method to find tool shape parameters that had a linear relationship with the end-milling conditions listed in the catalog. We used the response surface method and significant tool shape parameters obtained by clustering to derive end-milling condition. Milling experiments using a square end mill under two sets of end-milling conditions (conditions derived from the end-milling condition decision support system and conditions suggested by expert engineers) for difficult-to-cut materials (austenite stainless steel) showed that catalog mining can be used to derive guidelines for deciding end-milling conditions.
Machinability Study on Hard Milling of Ultra-High Strength Steel 30Cr3SiNiMoVA
Authors: Chen Ming , Xu Jin Yang , Liu Zhi Qiang , An Qing Long
Published: September 2012

The superior mechanical and physical properties of ultra-high strength steel 30Cr3SiNiMoVA have awarded the material such desirable and increasing demands in aerospace and aviation industries. Due to its excellent properties, 30Cr3SiNiMoVA is usually classified as a difficult-to-cut material. The machining process of ultra-high strength steel is often characterized by high cutting forces, low surface finish and severe tool wear. In actual production, hard cutting which is a profitable alternative to finish grinding is usually employed in order to improve machining efficiency and reduce processing cost. Therefore, this research concerns the machinability evaluation in hard milling of 30Cr3SiNiMoVA by using TiAlN coated carbide tools. The machinability of the steel was investigated with respect to cutting forces, surface roughness, chip morphology and tool wear, respectively. Finally, a comparative test was also conducted between hard milling and grinding process. The results pointed out that hard milling and coated tools were suitable, beneficial and effective for manufacturing ultra-high strength steel 30Cr3SiNiMoVA.
Application of Cavitation Aided Abrasive Machining to Manufacture of Micro Air Vents on Injection Molds
Authors: Lu N. , Ohashi K. , Hirashima A. , Shimizu A. , Tsukamoto S.
Published: September 2012

The purpose of this study is a practical application of the cavitation aided abrasive machining (CAAM). This study shows the machining effect of the precision abrasive machining on injection molds using the cavitation in a suction flow of slurry, which can easily finish to a fine surface by a simple apparatus. The cavitation occurred above the workpiece surface downstream of the restrictor tip because of the rapid decompression and then the abrasive grains in the water interfere with the workpiece surface by the cavitation impact. In this report, the possibility of application of the cavitation aided abrasive machining to the precision manufacturing of micro air vents on the rib of injection molds are generated by using masks of a certain thickness that are made on a special masking equipment, and the machining characteristics of micro air vents are investigated by analyzing the depth of micro grooves and the surface finish in machining of injection molds. When the depth of the micro grooves is approximately 1μm in the machining of 30 minutes, the manufacture of molding parts without burrs or residual voids is carried out by CAAM.
Deposition and Tribological Properties of CVD Diamond/Diamond-Like Carbon Composite Films
Authors: Shen Bin , Wang Liang , Chen Su Lin , Sun Fang Hong
Published: September 2012

The CVD diamond/diamond-like carbon composite film is fabricated on the WC-Co substrate by depositing a layer of Diamond-like Carbon film on the surface of conventional Micro- or Nano-crystalline diamond film. The hot filament chemical vapor deposition (HFCVD) method and vacuum arc discharge with a graphite cathode are adopted respectively to deposit the MCD/NCD and DLC films. A variety of characterization techniques, including filed emission scanning electron microscope (FE-SEM) and Raman spectroscopy are employed to investigate the surface morphology and atomic bonding state of as-deposited MCD/DLC and NCD/DLC composite film. The results show that both MCD/DLC and NCD/DLC composite films present similar surface morphology with the MCD and NCD films, except for scattering a considerable amount of small-sized diamond crystallites among the grain boundary area. The atomic-bonding state of as-deposited MCD/DLC and NCD/DLC composite films is determined by the top-layered DLC film, which is mainly consisted of amorphous carbon phase and no discernible sp3 characteristic peak can be observed from their Raman spectrum. Furthermore, the tribological properties of as-deposited MCD/DLC and NCD/DLC composite films is examined using a ball-on-plate reciprocating friction tester under both dry sliding and water-lubricating conditions, comparing with conventional DLC, MCD and NCD films. Silicon nitride balls are used as counterpart materials. For the CVD diamond/DLC composite films, the self-lubricating effect of top-layered DLC film is beneficial for suppressing the initial friction peak, as well as shortening the run-in period. The average friction coefficients of MCD/DLC and NCD/DLC composite films during stable sliding period are 0.07 and 0.10 respectively in dry sliding; while under water-lubricating condition, they further decreases to 0.03 and 0.07.
Thermal-Mechanical Analysis of Hybrid Spindle System Based on FEM
Authors: Wang Wan Shan , Guan Peng , Yu Tian Biao
Published: September 2012

The deformation of the spindle system is the main factor affecting the accuracy of ultra-high speed grinding. To calculate the deformation of ultra-high-speed grinding spindle system is required to consider not only the formation of structural deformation, but also the thermal deformation. Using the simulation method, oil temperature and grinding force are calculated in this paper. Based on these two factors, the thermal-mechanical deformation of the hybrid spindle system is analyzed and calculated with the method of FEM. the This article uses simulation methods, analysis and calculation of the oil film temperature rise and the grinding force caused by deformation of the liquid and hydrostatic spindle system factors. The methods presented in this paper can be used in digital design of various kinds of spindle systems, in order to improve the accuracy of the spindle system design.
Study on Microstructure and Friction of Bimetal 1.5Cr4.8Ni with Cast Iron and Low Carbon Steel
Authors: Zhang Qi , Jiang Zheng Yi , Xie Guo Liang , Wei Dong Bin , Han Jing Tao
Published: September 2012

A cast iron/low carbon steel sandwich-structured bimetal fabricated through composite casting, followed by hot rolling and hot compression (40% reduction) in a vacuum, and water quenched using Gleeble 3500 thermomechanical simulator. The microstructure of a predominantly martensitic structure is transferred to a matrix with an amount of austenite. The measured results show that the macro-hardness is significantly lower due to the evolution of matrix. A considerable amount of secondary carbides were precipitated from the matrix. This study also shows that a significant difference in the value of coefficient of friction (COF) at the end when hot rolling (HR) was tested under three sets of sliding wear conditions, while those for hot rolling and heat treatment (HT) tends to be merged. An increased wear resistance of interfacial zone is expectable.
Research on Digital Filters for Si Wafer Surface Profile Measurement - Design of Filters by Total Variation
Authors: Ojima Hirotaka , Nonomura Kazutaka , Zhou Li Bo , Shimizu Jun , Onuki Teppei
Published: September 2012

The underlying data form of a wafer is a matrix of length (or height) measurements. In the presence of noise, evaluation parameters are normally biased. The expectation value such as peak-to-valley and GBIR (global backside ideal range) is systematically larger than the “true” value. Correction and compensation need a large population of measurements to analytically estimate both bias and the uncertainty. In this study, approach to obtain the true value is to extract a “true” profile by filtering noise from the measured data. In previous paper, the digital filter with wavelet transformation (WT) is proposed and efficiency to remove the noise, however, the method is introduced the pseudo-Gibbs effect. Then, we propose the digital filter with new algorithm of total variation (TV). In this paper, the new algorithm of TV is proposed and the digital filter by new TV indicate that data is filtered without the pseudo-Gibbs effect. The digital filters by WT and new TV are applied on the sample data of actual measurement system to investigate their performance of noise reduction.
Research on the Key Technology of NC Abrasive Belt Grinding for the Leading and Trailing Edges of Aeroengine Blades
Authors: Huang Yun , Ye Xiao Xiao , Zhang Ming De , Fang Hong Wen
Published: September 2012

This document provides an analysis of the structure characteristics and grinding process requirements of leading and trailing edges, and proposes a grinding process of leading and trailing edges, established a uneven grinding margin model, research the quantitative grinding pressure control method of uneven margin, as well as the error compensation technology of blade machining deformation, and experiments were carried out on the basis of theories above. The experimental results demonstrate that: after grinding, the edge roundness improved greatly, dimensional accuracy of edge radius can reach ±0.07mm.Compared with the traditional manual polishing method, the grinding quality improved significantly.
Experimental Investigation on Grinding Surface Condition of 9Mn2V under Different Tempering Processes
Authors: Chen Ming , Dong Da Peng , Guo Guo Giang , An Qing Long
Published: September 2012

This paper investigates the surface condition of 9Mn2V in conventional surface grinding using SG abrasive under different tempering processes, which includes metallographic structure, micro-hardness, specific grinding energy, surface roughness, surface morphology and surface residual stress. The experimental results indicated that the specific grinding energy increased after the completion of tempering. The ground surface quality improved evidently with the times of tempering increasing. Meanwhile the ground surface was in a state of high tensile residual stress after quenching. After the second time of tempering, the residual stress had significantly been reduced.
Analysis to the Forces and Movement Characteristic of the Dispersal Phase in Swirling Flow Field
Authors: Li Kun , Li Xue Bin
Published: September 2012

Described the two-phase flow movement in the cyclone hyper-gravity field, and conducted a comprehensive analysis of the force and movement of the dispersed phase. Deduced the differential equations of the dispersed phase’s dynamic characteristics among the continuous phase. Then used MATLAB to calculate the symbol analytical solution for the movement characteristics with time. Laid the foundation for further in-depth understanding the behavior characteristics of the dispersed phase particles in the cyclone field.
The Implementation and Research of CAN Control Network
Authors: Dai Ai Ni , Zhao You Gang , Liu Jing
Published: September 2012

CAN bus has the advantages of high-reliability, real-time and low-price, so it is used widely. In this paper, we mainly discussed the network based on CAN bus, First, Provided the overall design plan, the structure feature and working principle of the control net based on CAN bus; and introduced the corresponding circuit structure of the intelligence control device, secondly, a new protocol for user layer communication based on CAN2.0B which is named Qucan_A is presented, Thirdly, the software based on the protocol Qucan_A between master nodes and slave nodes have been designed. In addition, the configuration and data management of the network have been designed. Finally, a monitoring example of the transformer substation has been realized, and it further verifies the advancement and practicability of the network in practice.
Experimental Analysis of Wear Mechanism and Tool Life in Dry Drilling of Al2024
Authors: Davoudinejad Ali , Ashrafi Sina Alizadeh , Hamzah Raja Ishak Raja , Niazi Abdolkarim
Published: September 2012

Aluminum alloy is widely used in industry and various researches has been done on machiability of this material mainly due to its low weight and other superior properties. Dry machining is still interesting topic to reduce the cost of manufacturing and environmental contaminations. In present study dry machining of Al 2024 investigated on tool life, tool wear mechanisms, hole quality, thrust force and torque. Different types of high speed steel (HSS) tools utilized at constant feed rate of 0.04 mm/rev and cutting speeds within the range of 28 and 94 m/min. Experimental results revealed that HSCo drills, performed better than HSS drills in terms of tool life and hole quality. The main wear mechanisms which analyzed by scanning electron microscope found abrasive and adhesion wear on flank face, besides, BUE observed at chisel and cutting edges. However tool wear and BUE formation found more significant at high cutting speed. In terms of thrust force, two facet HSCo tools, recorded higher thrust force than four facet HSS drills.
The Influence of Gravity Inaccuracy in Underwater ESG Inertial Navigation System
Authors: Gao Wei , Zhao Bo
Published: September 2012

Gravity affects the three solution channels of ESG inertial navigation system, which makes the influence of gravity complex. For ESG inertial navigation system, The gravity inaccuracy is composed of three parts, the first part is the calculation error of the normal gravity; the second part is the vertical deflection between the normal gravity and geoid normal; the third part is gravity anomaly caused by the uneven distribution of Earth's density. By solving the error equations and simulating, we quantitatively analyze the influence of gravity inaccuracy in the ESG inertial navigation system. The conclusion will provide a theoretical basis for the compensation of gravity inaccuracy.
Estimating Gyro Drift of Strapdown Inertial Navigation System Based on Star Sensor
Authors: Zhou Guang Tao , Shi Gui Min , Zhang Lei , Li Kai
Published: September 2012

In the strapdown inertial navigation system (SINS), gyro drift will result in navigation errors. A new algorithm based on star sensor is proposed in this paper to estimate gyro drift. The paper analyzed the working principle of star sensor and the technique of estimating gyro drift. Gyro drift can be estimated through the high-precision attitude information provided by a star sensor. Kalman filter is used in the integrated navigation model. Simulation results show that the proposed algorithm can estimate gyro drift accurately and improve the precision of SINS.
Study on Dynamic Response of Torsional Vibration of Turbo-Generator Unit Caused by Short Circuit Fault
Authors: He Cheng Bing , Chen Dong Chao , Gu Yu Jiong
Published: September 2012

When short circuit faults happen near power plant or generator terminal, severe transient torque shock will act on the shaft system, which seriously affects the safe and stable operation of the unit. Using the increment transfer matrix method, the dynamic responses of torsional vibrations are calculated in this work. Combined with the complex Morlet wavelet and time-frequency contour map, the time-frequency domain characters of dynamic torque are analyzed. The analyzed results show that the torque value caused by three phase short circuit fault is largest. The order of torque value from high to low is two phase short circuit to ground, two phase interphase short circuit and single phase short circuit. The electric distance between short circuit point and generator is more short, and the torsional vibration is more serious.
Based on the Calculation and Analysis of the Separator of the Strength of the Cast Iron Base
Authors: Zhong Bo
Published: September 2012

Pressure component of the magnetic base with gray cast iron strength analysis methods and intensity conditions the calculation there are obvious flaws and inadequacies. Test, analysis of this issue, the introduction of the internal friction, calculate and analyze the effective value of the internal friction angle φ to obtain a more accurate, more in line with the actual strength conditions
CAD Course in Engineering Education
Authors: Gradinscak Marija
Published: September 2012

Globalisation is accelerating and with it rapid technological change has resulted in the environment being dramatically impacted by constant and significant change. The global job market requires excellent technical skills, so we must educate students for more sophisticated jobs. Today, engineers must be practical and creative, able to work with different people, be quick to solve problems and make critical business decisions, whilst being professional and ethical. Spatial visualisation skills play a significant role in engineering fields, particularly for mechanical engineering students whose fields rely heavily on visualisation. This paper presents the CAD course with computer graphics components that would help in enhancing students’ powers of visualisation using CAD applications.
The Restrain Theory of Gyro Constant Error with Rotation Modulation
Authors: Ben Yue Yang , Yang Xiao Long , Wu Xiao , Li Qian
Published: September 2012

With the rotation modulation, a strapdown inertial navigation system (INS) can keep high accuracy navigation without high accuracy gyro and high accuracy accelerometer. Firstly we give the error equation of strapdown INS, and then deduct the navigation error propagation of system. From partial analysis way, the modulation process of gyro constant error is obtained. Form global analysis way, the navigation error roused by constant error and the modulation effects are deducted here.
Based on PLC and GM's Two-Speed Elevator Transducer System Design
Authors: Zang Hua Dong
Published: September 2012

This paper introduces the use of PLC control technology design and development of eight sightseeing elevator system, the completion of the operation of the elevator, elevator doors closed, both inside and outside the box sedan features such as call response; combination of general-purpose inverter, completed VVVF elevator to achieve double-speed operation, thereby enhancing the operational efficiency of the elevator, saving valuable time passengers; through the voice circuit at departure and arrival stations broadcast information floors; the use of touch screen technology designed chair called box, alarm function, In addition, the use of configuration Wang software development elevator remote monitoring system, remote monitoring device through the elevator lifts running real-time monitoring to ensure the normal operation, greatly enhanced the safety and reliability.
Design of Composite Brakes Using Knowledge-Based Design Methodology
Authors: Setiawan Rachman , Yulianto E.
Published: September 2012

In designing modern friction materials that are normally made of composite materials, a more systematical approach is needed in order to select the most appropriate composition of raw materials for specific applications. Here, knowledge-based design methodology has been formulated for composite brake design application, that consists of: design database generation from experiments, metamodelling, and global optimization processes. The objective function has incorporated, among others, the uncertainties introduced in the experimentally-obtained design database, so that providing the optmization results with the information of variation. The application of the methodology has been demonstrated to two cases, i.e. train brake and motorcycle brake pad, with the optimization results close to the targetted values and the information of output variation, as intended.
Building Three-Dimensional Merged Surface Model from Polygonal Models
Authors: Du Jian Jun , Guo Xin Yu , Lu Sheng Lian , Xiao Bo Xiang , Wu Jian Wei
Published: September 2012

Three-dimensional surface merging plays an important role in rapid prototyping manufacture, physically based modeling and finite element analysis. In this paper, a rapid merging method is proposed to build three-dimensional water-proof surface model from polygonal models. To rapidly determine merging boundaries, collision detection techniques are used to obtain the intersection triangle pairs between the two input models, and then the intersection line loops are accurately computed. Furthermore, triangle tessellation and edge searching method is used to generate new triangles and classify each triangle in models into different triangle sets. Finally, an inclusion test determines the position of each triangle set and stitches the labeled triangle sets into the merged model. The experimental results demonstrate the robustness and adaptability of the presented method.
Measurement of Joint Element Transmission Error in a Humanoid Walking Robot
Authors: Itakura Kiyoto , Koike Hitonobu , Kida Katsuyuki , Kanemasu Kenji
Published: September 2012

In the present work, a prototype of a joint element to be used in lightweight and compact joints for tall humanoid robots is investigated. The newly developed element consists of a harmonic drive gearing device, a multi axis mechanism and a resin bush. Bushes produced from two kinds of bush materials: poly-ether-ether-ketone (PEEK) and polyacetal (POM) were tested. Furthermore, two testing machines to evaluate the joints were constructed: for the power input-output transmission error measurement and for the investigation of the influence of walking-load on bush wear.
Modal Analysis of the Surface Grinding Machine Structure through FEM and Experimental Test
Authors: Pakzad Sajjad , Rajab Aslan Khani Sheykh , Mahboubkhah Mehran , Ettefagh Mir Mohammad , Masoudi Omid
Published: September 2012

Machine tool vibrations have great impact on machining process. In this paper the dynamic behavior and modal parameters of surface grinding machine is presented. For this purpose, the CAD (computer aided design) model of the surface grinding machine structure is provided in catia and then Natural frequencies and mode shapes of the machine tool structure are carried out through FEM (finite element method) modal analysis under ansys. The model is evaluated and corrected with experimental results by modal testing on surface grinding machine. Finally, the natural frequencies and mode shapes obtained by both experimental and FEM modal analysis are compared. The results of two methods are in widely agreement.
Study of Security of Virtual Host Based on XML
Authors: Yu Su , Brewster Jon. J.
Published: September 2012

When some companies or individuals rent the virtual host as their own servers, there is a problem: how to ensure the security of their networked database? This paper discusses security of exchanging information between virtual host and clients using XML(Extensible Markup Language). This paper also provides a safe way based on RSA algorithm and XML security suite applied in estate company
Fabrication of Membrane-Electrolyte Assembly with Nanocomposite for Direct Methanol Fuel Cell
Authors: Chang Ho , Kao Mu Jung , Lee Kuang Ying
Published: September 2012

This study aims to deal with the preparation of membrane-electrolyte assembly (MEA) of Pt/Ru/C nanocomposite as well as connecting to a direct methanol fuel cell and using PCB process packaging to test the efficiency of the DMFC. The components assembled in DMFC are including anode flow field plates, MEA and current collector.Using PCB boards for the anode flow field plates as well as the electicity collector plates and the type of flow field plate adopts serpentine flow field. For the efficiency of DMFC, liquid motors are used to press methanol mixed solution at specific temperature into DMFC. Besides, the cathode of DMFC adopts natural-breath method with air and uses DC electronic load to activate DMFC to investigate operating voltage and further to set constant voltage to measure current to calculate the efficiency of DMFC. Initial results of I-V curve show that self-developed MEA of Pt/Ru/C nanocomposite can enhance around 0.2% current density of DMFC after being assembled like commercial MEA
Forming Complicated Surface in Shipyard Using Neural Network System
Authors: Nguyen Truong Thinh
Published: September 2012

Determining the positions of triangle heating in and parameters of heating process are important for deforming the concave surfaces in shipyard, as well as airplane. The objective of this study was to develop an artificial neural network (ANN) model to predict positions of induction heating and parameters of heating process based on analytical solutions. This model of ANN can help manufacturers determine the positions of induction heating lines and their heating parameters to form a desired shape of plate. The backpropagation neural network systems for determining line-heating positions from object shape of plate are presented in this paper. An artificial neural network model is developed with the relationship between the desired shape of plate and the paths of induction heating. The input data are vertical displacements of plate and the output data are selected heating lines composed by the areas. The outputs of the models were positions of induction heating on plate as well as their parameters. Simulated values obtained with neural network correspond closely to the experimental results.
Simulation Analysis of Working Process for Core Seed Metering Device Based on Discrete Element Method
Authors: Ji Yu Jie , Li Cheng Hua , Xue Hong Da
Published: September 2012

Discrete element method is an important technical tool for analysis of motion law of granular material. Based on the principle of discrete element method, using linear viscoelastic contact mechanics model, simulation calculate for discrete element simulation was developed by MFC. Through the combination of arc modeling a geometric model of the different core seed were built, and simulation of the work process of corn precision metering device was conducted. Suitability of parameters on working procedure of the metering device was analyzed.
Stick-Slip Simulation of Feeding System in Silicon Ultra-Precision Grinding Machine
Authors: Sha Zhi Hua , Zhang Shao Xing , Wang Yi , Zhang Sheng Fang
Published: September 2012

Mono-crystalline silicon is the typical substrate material in integrated circuits manufacturing, and machining precision and surface quality of the silicon wafer impacts on the quality and performance of the electronic products directly. Silicon grinding technology has high accuracy, low cost and can obtained high surface quality, which has become the mainstream of silicon ultra-precision machining. Stick-slip of feeding system in silicon ultra-precision grinding machine is an important factor which influencing the machining precision of the silicon wafer. In this paper, based on the structure analysis of feeding system in a certain type of silicon ultra-precision grinding machine, the rigid body coupling virtual prototype model of the feeding system is established using ADAMS, the factors which influencing the stick-slip is analyzed deeply via the dynamic simulation of the virtual prototype.
Improvement on Supporting Machine Learning Algorithm for Solving Problem in Immediate Decision Making
Authors: Niazi Abdolkarim , Redzuan Norizah , Hamzah Raja Ishak Raja , Esfandiari Sara
Published: September 2012

In this paper, a new algorithm based on case base reasoning and reinforcement learning (RL) is proposed to increase the convergence rate of the reinforcement learning algorithms. RL algorithms are very useful for solving wide variety decision problems when their models are not available and they must make decision correctly in every state of system, such as multi agent systems, artificial control systems, robotic, tool condition monitoring and etc. In the propose method, we investigate how making improved action selection in reinforcement learning (RL) algorithm. In the proposed method, the new combined model using case base reasoning systems and a new optimized function is proposed to select the action, which led to an increase in algorithms based on Q-learning. The algorithm mentioned was used for solving the problem of cooperative Markov’s games as one of the models of Markov based multi-agent systems. The results of experiments Indicated that the proposed algorithms perform better than the existing algorithms in terms of speed and accuracy of reaching the optimal policy.
High Birefringence and Negative Dispersion Effect of Hybrid-Core Photonic Crystal Fiber
Authors: Xu Ding Jie , Song Hong Ru , Wang Wei , Fan Yue
Published: September 2012

A novel type of hybrid-core photonic crystal fiber is proposed, whose core is composed of center-directionally decrescent air holes arrayed as pentagonal and an octagonal structure. Characteristics of the proposed PCF are analyzed theoretically by using all vector finite element method (V-FEM). Results show that high-birefringence and negative dispersion are obtained over the wavelength range from 0.8µm to 1.8µm, and the maximum of birefringence reaches 1.36×10-2 and negative dispersion achieves -600 ps•nm-1•km-1~-60 ps•nm-1•km-1, which will fulfill the requirement of high-birefringence polarization maintaining fiber fabricating and wideband dispersion compensating.
Prediction of Geographical Criminal's Anchor Point Based on Bayesian-Grid Search
Authors: Yan Ya Wen , Lu Xin Zhong , Meng Ji Xian , Lu Yi Jia
Published: September 2012

Two new methodologies are established based on existing frameworks. The Bayesian model take ages, intellectual capability, transportation into consideration to find the offender’s anchor point. The grid search model investigation start with the highest score grid cell first for investigation and proceed down the list of grid cells sorted by score, which implement searching according to simulated annealing program . Making use of two different models we generate an integrated model and test their reliability according to historical serial crime samples.