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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Precision Engineering
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Journal DOI :
Korean Society of Precision Engineering
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Volume & Issues
Volume 17, Issue 12 - Dec 2000
Volume 17, Issue 11 - Nov 2000
Volume 17, Issue 10 - Oct 2000
Volume 17, Issue 9 - Sep 2000
Volume 17, Issue 8 - Aug 2000
Volume 17, Issue 7 - Jul 2000
Volume 17, Issue 6 - Jun 2000
Volume 17, Issue 5 - May 2000
Volume 17, Issue 4 - Apr 2000
Volume 17, Issue 3 - Mar 2000
Volume 17, Issue 2 - Feb 2000
Volume 17, Issue 1 - Jan 2000
Selecting the target year
Micro Machining Technology Using Turning and Grinding
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 5~13
Processing of Micro-Parts by Metal Forming
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 14~19
Fabrication of Micro-Shapes Using EDM and Ultrasonic Machining
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 20~27
Laser Beam Application and Technology in Micro Machining
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 27~35
Laser Beam Application and Technology in Micro Machining
Yoon, Kyung Ku ; Lee, Sung Kuk ; Kim, Jae Gu ; Shin, Bo Sung ; Choi, Doo Sun ; Whang, Kyung Hyun ; Park, Jin Yong ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 28~28
The Present State and Prospect of LIGA Technology
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 36~44
Application of Bio-MEMS Technology on Medicine and Biology
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 45~51
Silicon Micromachining Technology and Industrial MEMS Applications
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 52~58
A Study on Rapid Prototyping using VRML Model
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 63~73
Internet becomes very common tool for communication and data sharing. Virtual reality(VR) on web browser, and virtual prototyping and virtual manufacturing is widely used in many engineering folds. The reduction of overall development process and error minimization during data conversion becomes very crucial where sharing data via Internet and VR. This paper deals with the advantage and disadvantage of VRML format used in RP(Rapid Prototyping), and a software for RP data preparation is developed. If VRML format as an international standard for VR, is replaced with STL format, the weak points of STL format can be overcome and the technique related to virtual prototyping and virtual manufacturing can be addressed more systematically by sharing the data. The system developed in this work shows a good window to get access to a more realistic observation of an object fur an RP system from a long remote sites in a more systematic way.
Development of Automated J-Integral Analysis System for 3D Cracks
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 74~79
Integrating a 3D solid modeler with a general purpose FEM code, an automatic nonlinear analysis system of the 3D crack problems has been developed. A geometry model, i.e. a solid containing one or several 3D cracks is defined. Several distributions of local node density are chosen, and then automatically superposed on one another over the geometry model by using the fuzzy knowledge processing. Nodes are generated by the bucketing method, and ten-noded quadratic tetrahedral solid elements are generated by the Delaunay triangulation techniques. The complete finite element(FE) model generated, and a stress analysis is performed. In this system, burden to analysts fur introducing 3D cracks to the FE model as well as fur estimating their fracture mechanics parameters can be dramatically reduced. This paper describes the methodologies to realize such functions, and demonstrates the validity of the present system.
A Real-Time Graphic Driving Simulator Using Virtual Reality Technique
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 80~89
Driving simulators provide engineers with a power tool in the development and modification stages of vehicle models. One of the most important factors to realistic simulations is the fidelity obtained by a motion bed and a real-time visual image generation algorithm. Virtual reality technology has been widely used to enhance the fidelity of vehicle simulators. This paper develops the virtual environment for such visual system as head-mounted display for a vehicle driving simulator. Virtual vehicle and environment models are constructed using the object-oriented analysis and design approach. Based on the object model, a three-dimensional graphic model is completed with CAD tools such as Rhino and Pro/ENGINEER. For real-time image generation, the optimized IRIS Performer 3D graphics library is embedded with the multi-thread methodology. The developed software for a virtual driving simulator offers an effective interface to virtual reality devices.
A Study on the Cutting Fluid Effectiveness in Mechanical and Thermal Terms Simultaneously for Environmentally Conscious Machining
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 90~97
This paper presents a methodology to analyze the cutting fluid effectiveness in mechanical and thermal terms simultaneously using finite element method and experimental work. Cutting fluid plays many roles in metal cutting process. Mechanically-thermally coupled effectiveness of cutting fluids affect to friction coefficient at tool-workpiece interface and cutting temperature and chip control, surface finish, tool wear and form accuracy. Through this study, it can be explained that the critical behavior of cutting fluids will be able to apply optimal environmentally conscious machining process.
Development of Rotating Machine Vibration Condition Monitoring System based upon Windows NT
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 98~105
In this study, we developed rotating machine vibration condition monitoring system based upon Windows NT and DSP Board. Developed system includes signal analysis module, trend monitoring and simple diagnosis using threshold value. Trend analysis and report generation are offered with database management tool which was developed in MS-ACCESS environment. Post-processor, based upon Matlab, is developed for vibration signal analysis and fault detection using statistical pattern recognition scheme based upon Bayes discrimination rule and neural networks. Concerning to Bayes discrimination rule, the developed system contains the linear discrimination rule with common covariance matrices and the quadratic discrimination rule under different covariance matrices. Also the system contains k-nearest neighbor method to directly estimate a posterior probability of each class. The result of case studies with the data acquired from Pyung-tak LNG pump and experimental setup show that the system developed in this research is very effective and useful.
Design of Stable Controller to Sudden A/C Disturbance
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 106~112
The purpose of this paper is to study on the control of the engine idle speed under sudden A/C load which is one of the most severe disturbances on engines. Three types of the closed-loop controller are developed for the stable engine idle speed control. The input of the controller is an error of rpm. The output of the controller is an ISCV duty cycle. The anticipation delay is considered to deal with the delay time of the air mass in engine. The PID, Fuzzy and PID-type Fuzzy controllers with the anticipation delay have improved the engine idle speed condition more than current ECU map table under the A/C load.
Development of an Algorithm for Predictable Navigation and Collision Avoidance Using Pattern Recognition of an Obstacle in Autonomous Mobile Robot
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 113~123
In the navigation for a mobile robot, the collision avoidance with unexpected obstacles is essential for the safe navigation and it is independent of the technique used to control the mobile robot. This paper presents a new collision avoidance algorithm using neural network for the safe navigation of the autonomous mobile robot equipped with CAN and ultrasonic sensors. A tracked wheeled mobile robot has a stability and an efficiency to move on a rough ground. And its mechanism is simple. However it has difficulties to recognize its surroundings. Because the shape of the tracked wheeled mobile robot is a square type, sensor modules are generally located on the each plane surface of 4 sides only. In this paper, the algorithm using neural network is proposed in order to avoid unexpected obstacles. The important character of the proposed algorithm is to be able to detect the distance and the angle of inclination of obstacles. Only using datum of the distance and the angle, informations about the location and shape of obstacles are obtained, and then the driving direction is changed. Consequently, this algorithm is capable of real time processing and available for a mobile robot which has few sensor modules or the limited sensing range such as a tracked wheeled mobile robot. Effectiveness of the proposed algorithm is illustrated through a computer simulation and an experiment using a real robot.
A Study on Manufacturing Resin-based Blow Mold using SLS Parts and Forming Prototype-car Parts
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 124~131
Rapid Prototyping(RP) models are no longer used only for design verification. Currently, parts built utilizing layer manufacturing technology can be employed as functional prototypes and as patterns or tools for different manufacturing processes such as vacuum casting, investment casting, injection molding, precise casting and sand casting. This trend of Rapid Prototyping application meets the requirement of concurrent engineering and its range covers a more spreaded area. The aim of this paper is saving the manufacturing lead time and cost of plastic parts having hollow space shapes used by prototype-car. Using rapid prototype patterns, made by the Selective Laser Sintering(SLS) technique, a new approach of manufacturing resin-based blow mold is discussed. It has a great potential fur making prototype-car parts with the batch size of under 200 parts, in case of rapid modification due to a subsequent design changes in developing stage. So, the process proposed in this research shows reduction of process time and manufacturing cost when compared with the conventional process such as a Zinc Alloy fur Stamping(ZAS) mold.
A Study of an Automatic Tip-to-Workpiece Distance Control System for Plasma Arc Cutting
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 132~140
Plasma arc cutting is one of the most widely used processes in metal cutting fields and is a process that produces parted metal plates by cutting them with an arc plasma established between the electrode tip and the plate(workpiece). When the tip-to-workpiece distance varies during cutting, the cut quality, for example the kerf width, is deteriorated by the change of plasma arc. The variations of tip-to-workpiece distance are due to the different factors such as inaccuracies in setting the torch or workpiece, thermal distortions during cutting, and uneven surface of workpiece. The control to keep the tip-to-workpiece distance constant is thus indispensable to improve the flexibility of automatic plasma arc cutting system applications. In this study, an arc sensor which utilizes the electrical signal obtained from the plasma arc itself was developed. The arc sensor has an advantage that no particular sensing device is necessary and real-time sensing of the tip-to-workpiece distance is possible directly under the plasma arc. The relationship between plasma arc voltage and tip-to-workpiece distance was determined through the repeated experimental results. The model was used for developing an automatic tip-to-workpiece distance control system of plasma arc cutting. It could be shown that the proposed system has a successful capability of tip-to-workpiece distance control.
Development of Flexible Tool for Curved Surface Finishing
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 141~146
A flexible tool is developed for automatic finishing of curved surfaces without any complicated control technique on three-axes machining center. The tool is made of thermosetting polyurethane elastomer on the surface of which aluminum oxide abrasives are mounted. Performance and durability of the tool are examined by finishing ball-end milled surfaces of high-alloyed tool steel. It is demonstrated that the tool removes cusp successfully without changing overall surface shape in relatively short time.
A Study of Developing the Low Noise Circular Saw Blade
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 147~155
To reduce the noise from wood cutting saw at the saw mill(lumber mill) or a construction area, some multi-layer sandwich saw blades which a aluminum or copper plate was inserted between the two steel plates were developed and were tested of the wood cutting noise level at various test places. From the research, it was found that the multi-layer saw blade with copper or aluminum plate between steel plates and spot welded 60 points could reduce the wood cutting sound level about 8.3 dB(97.031 dB - 88.743 dB) at indoor test and 3.8 dB(84.805 - 81.638 dB) at field test.
A Study on the Minimum Zone Algorithm for the Calculation of Roundness
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 156~161
Least Squares and Minimum Zone method are known for obtaining a datum or a continuous approximate function of measured data. This study is for a Minimum Zone algorithm for a circle, which is useful to obtain the exact roundness from the reference circle of measured data. The proposed method is compared with the Least Squares Limacon method and Chrystal-Peirce algorithm. A computational algorithm for the Minimum Zone circle is suggested and results in less roundness than the other two methods. This Minimum Zone circle method will be used for other geometrical measured data, such as plane or sphere for obtaining the exact flatness or sphericity.
Implementation of a Parallel Inverted Pendulum System with Decoupling Control
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 162~169
In this paper, we develop a parallel inverted pendulum system that has the characteristics of the strongly coupled dynamics of motion by an elastic spring, the time-variant system parameters, and inherent instability, and so on. Hence, it is possible to approximate some kinds of a physical system into this representative system and to apply the various control theories to this system in order to verie their fidelity and efficiency. For this purpose, an experimental system of the parallel inverted pendulum has been implemented, and a control scheme using the eigenstructure assignment for decoupling control is presented in comparison with the conventional LQR optimal control method. Furthermore, this system can be utilized as a testbed to develop and evaluate new control algorithms through various setups. Finally, in this paper, the results of the experiment are compared with those of numerical simulations for validation.
Evaluation of Ease of Exchange of Subassembly Considering Module
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 170~180
In this paper, to evaluate ease of exchange of subassembly considering module, it needs to analyze structure and function of subassembly, assembly and disassembly process. Exchange process of module can be divided into pre-process and in-process, and determination factors of exchange process are defined by analyzing characteristics of assembly and disassembly process. Based on the analysis of characteristics for structure and function of subassembly, influential factors of module can be proposed. Considered the interrelationship between determination factors of ease of exchange and influencing factors of module, ease of exchange can be evaluated.
Reverse Engineering of 3D Compound Shapes using Delaunay Triangulation
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 181~188
The objective of this research is to develop an efficient reverse engineering method of 3-dimensional compound surfaces for raped prototyping process. As a first step, several image processing techniques were applied to the measured data obtained using laser scanner. And the boundary information of the compound surface were extracted to divide the surface into several separate regions. As a next step, the Delaunay triangulation method were applied to reconstruct the surface based on the measured data and the boundary information. Finally, the STL file were created for the rapid prototyping process. Required simulations and experiments were performed and the results were analyzed to show the effectiveness of the proposed methods.
Vibration Suppression Control of Constrained Spatial Flexible Manipulators
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 189~195
For free motions, vibration suppression of flexible manipulators has been one of the hottest research topics. However, for constrained motions, a little effort has been devoted for vibration suppression control. Using the dependency of elastic deflections of links on contact force under static conditions, vibrations for constrained planar two-link flexible manipulators have been suppressed successfully by controlling the contact force. However, for constrained spatial multi-link flexible manipulators, the vibrations cannot be suppressed by only controlling the contact force. So, the aim of this paper is to clarify the vibration mechanism of a constrained, multi-DOF, flexible manipulator and to devise the suppression method. We apply a concise hybrid position/force control scheme to control a flexible manipulator modeled by lumped-parameter modeling method. Finally, a comparison between simulation and experimental results is presented to show the performance of our method.
Derivation of Real Values from Imaginary Roots by Altering Prescribed Positions in the Precision Point Synthesis of Mechanisms
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 196~202
In the precision point synthesis of mechanisms, it is usually required to solve a system of polynomial equations. With the aid of efficient algorithms such as elimination, it is possible to obtain all the solutions of the equations in the complex domain. But among these solutions only real values can be used fur real mechanisms, while imaginary ones are liable to be discarded. In this article, a method is presented, which leads the imaginary solutions to real domain permitting slight alteration of prescribed positions and eventually increases the number of feasible mechanisms satisfying the desired motion approximately. Two synthesis problems of planar 4-bar path generation and spatial 7-bar motion generation are given to verify the proposed method.
An Analysis of the Mask Vibration Considering the Damping Wire
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 203~208
The vibration of a mask degrades the color purity in CRT Therefore, a damping wire is put into contact with the mask to reduce the vibration in perfectly flat CRT. In this study, we analyzed the vibration of the mask contacting with the damping wire using FEM. First we calculated the natural frequencies and mode shapes of the mask by modal analysis, and compared them with the measured results to confirm our finite element model. The modal analysis of the wire was also performed to investigate resonance with the mask. Finally, the transient dynamic analysis of the mask contacting with the wire was performed. The vibration of the mask was measured to confirm our analysis, and the results are in good agreement with the analysis.
Calibration of Glove-Like Hand Input System for Wearable Computer
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 209~216
Recently, Wearable Computers have been applied to medical equipments, inspection system, military and various fields of industries. To support the various application of wearable computer, many researches into the input device for wearable computer have been executed. This paper describes the glove-like hand input system for wearable computer. the characteristics of sensed values, and coupling effects between each sensor. Using these characteristics and coupling effects, the general relation between flexion angles of joints and the values from sensors are proposed as exponential functions. Also, the error range of sensed values is proposed and the glove-like hand input system is calibrated as well by the experiments.
Separation of Superimposed Pulse-Echo Signal for Improvement of Resolution of Scanning Acoustic Microscope -Deconvolution Technique Combined with Wavelet Transform-
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 217~225
Scanning Acoustic Microscope (SAM) is used as an important nondestructive test tool in semiconductor reliability evaluation and failure analysis. However, inspections of chip attach adhesive interface fer thin chip has proven difficulty as the reflected signals from the chip top and bottom are superimposed. In this paper, in order to overcome this difficulty, a new signal processing method based on the deconvolution technique combined with the wavelet transform is proposed. The wavelet transform complements a disability of deconvolution technique of which performance largely decreases when the waveform of target signal is not identical to that of reference signal. Performances of the proposed method are demonstrated by through computer simulations using model signal and experiments for the fabricated semiconductor samples, and satisfactory results are obtained.
The Micro Heat Flux Sensor using Electroplated Copper layers
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 226~231
New types of the micro heat flux sensor are designed and fabricated using SU-8 and Cu electroplating. And then calibrated under convection environment. The thermal path was made by SU-8 structure and electroplated Cu layers. The bottom surface of the micro heat flux sensor receives the heat flux from the wall, Then the heat flows along the Cu layers and drains out to the environment with producing the temperature difference at the upper layer of Cu. By measuring this temperature difference, the heat flux from the wall can be obtained. The temperature difference is measured by thermopile which is composed of Ni-Cr pairs or Al-chromel pairs. The calibration is accomplished under convection environment because it is most frequent situation. The range of the sensitivity is 0.11~2.02
) for the various heat flux and Reynolds numbers.
The OMM System for Machined Form and Surface Roughness Measurement Concerned with Volumetric Error
Journal of the Korean Society for Precision Engineering, volume 17, issue 7, 2000, Pages 232~240
Machining information such as machined form and surface roughness accuracy is an important factor for manufacturing precise parts. To this regard, OMM(On the Machine Measurement) has been issued for last several decades to alternate with CMM. In this research, measuring system consisting of a laser probe is developed for machined form and surface roughness measurement on the machine tool. The obtained machined form accuracy is compared with reference one defined in CAD model. The measured surface roughness data is compared with measured master surface beforehand. Furthermore, using the pre-defined volumetric error map approach compensates the geometric accuracy of the machine tool. The overall performance is compared with CMM, and verified the feasibility of the measurement system.