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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Precision Engineering
Journal Basic Information
Journal DOI :
Korean Society of Precision Engineering
Editor in Chief :
Volume & Issues
Volume 21, Issue 12 - Dec 2004
Volume 21, Issue 11 - Nov 2004
Volume 21, Issue 10 - Oct 2004
Volume 21, Issue 9 - Sep 2004
Volume 21, Issue 8 - Aug 2004
Volume 21, Issue 7 - Jul 2004
Volume 21, Issue 6 - Jun 2004
Volume 21, Issue 5 - May 2004
Volume 21, Issue 4 - Apr 2004
Volume 21, Issue 3 - Mar 2004
Volume 21, Issue 2 - Feb 2004
Volume 21, Issue 1 - Jan 2004
Selecting the target year
Reliability Testing for Sensor and Instruments
Choi Man-Yong ; Park Jeong-Hak ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 7~12
Excimer Laser Ablation of Polymer for Electroformed Mold
Lee Jae Hoon ; Shin Dong Sig ; Suh Jeong ; Kim To Hoon ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 13~20
Manufacturing process for the microfluidic device can include such sequential steps as master fabrication, electroforming, and injection molding. The laser ablation using masks has been applied to the fabrication of channels in microfluidic devices. In this study, manufacturing of polymer master and mold insert for micro injection molding was investigated. Ablation of PET (polyethylene terephthalate) by the excimer laser radiation could be used successfully to make three dimensional master fur nickel mold insert. The mechanism fur ablative decomposition of PET with KrF excimer laser
was explained by photochemical process, while ablation mechanism of PMMA (polymethyl methacrylate) is dominated by photothermal process, the .eaction between PC (polycarbonate) and KrF excimer laser beam generate too much su.face debris. Thus, PET was adopted in polymer master for nickel mold insert. Nickel electroforming using laser ablated PET master was preferable for replication method. Finally, it was shown that excimer laser ablation can substitute for X-ray lithography of LIGA process in microstructuring.
Development of Face Milling Cutter Body System for High Speed Machining
Jang Sung-Min ; Maeng Min-Jae ; Cho Myeong-Woo ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 21~28
In modem manufacturing industries such as the airplane and automobile, aluminum alloys which are remarkable in durability have been utilized effectively. High-speed machining technology for surface roughness quality of workpiece has been applied in these fields. Higher cutting speed and feedrates lead to a reduction of machining time and increase of surface quality. Furthermore, the reduction of time required for polishing or lapping of machined surfaces improves the production rate. Traditional milling process for high speed cutting can be machined with end mill tool. However, such processes are generally cost-expensive and have low material removal rate. Thus, in this paper, face milling cutter which gives high MRR has developed face milling cutter body for the high speed machining of light alloy to overcome the problems. Also vibration experiment to detect natural frequency in free state and frequency characteristics during machining are performed to escape resonance.
A Study on a Microreplication Process for Real 3D Structures Using a Soft Lithography
Chung Sungil ; Park Sunjoon ; Lee Inhwan ; Jeong Haedo ; Cho Dongwoo ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 29~36
In this paper, a new replication technique for a real 3D microstructure was introduced, in which a master Pattern WES made of photo-curable epoxy using a microstereolithography technology, and then it was transferred onto an epoxy-copper particle composite. A helical gear was selected as one of the real 3D microstructure for this study, and it was replicated from a pure epoxy to an epoxy composite. In addition, the transferability of the microreplication process was evaluated, and the properties of :he epoxy composite were compared to that of the pure epoxy, including hardness, wear-resistance and thermal conductivity.
Analysis of the Performance of Magnetic Abrasive Deburring according to Powder Characteristics
Chae Jong-Won ; Ko Sung-Lim ; Baron Yuri M. ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 37~43
The performance of magnetic abrasive finishing fur surface is evaluated by the characteristic curve. The characteristic curve is generated by experiment in surface finishing. For experiment, new magnetic inductor is designed and manufactured. 15 kinds of powders are provided to find the relationship between powder characteristic and finishing performance. As powder, Fe-TiC. Polymer-TiC and Fe-NbC are used with different size. The size of abrasives and location are also important factor for the performance. From characteristic curve, two index are obtained, which specify the initial finishing performance and endurance of finishing performance. It is proved that the performance index can be applied to select proper powder for efficient deburring. It is shown that the characteristic curve can be used as good tools for evaluating powder performance in surface finishing and deburring.
Characteristics of RC Circuit with Transistors in Micro-EDM
Cho Pil Joo ; Yi Sang Min ; Choi Deok Ki ; Chu Chong Nam ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 44~51
In a micro-EDM, it is well known that an RC circuit is suitable as a discharge circuit because of its low pulse width and relatively high peak current. To increase machining speed without changing unit discharge energy, charge resistance should be decreased. But, when the resistance is very low, continuous (or normal) arc discharge occurs, electrode wear increases and machining speed is reduced remarkably. In this paper, an RC circuit with transistors is used in a micro-EDM. Experimental results show that the RC circuit with transistors can cut off a continuous (o. normal) arc discharge effectively if the duty factor and switching period of the transistor are set up optimally. Through experiments with varying charge resistances, it is shown that the RC circuit with transistors has about two times faster machining speed than that of an RC circuit.
Interference Check and NC Data Optimization through Machine Simulation in 5 Axises Machining of a Vehicle Parts of Aluminum Alloy
Kim Hae Ji ; Lee In-Su ; Kim Nam Kyung ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 52~59
This paper shows about the machine simulation embodiment when it happens NC equipment and between workpiece and interference in 5 axises machining of aluminium alloy a vehicles parts. And this research has been chosen because of the highest equipment interference occurrence rate at a vehicles parts processing of 5 axises horizontal machine. It can verify simulation and machining process through correlation of their dynamic relations, interference, collision as embodied virtual manufacturing system of machine, workpiece, and holder etc. That is necessary element in shape of machine tool, function and processing in imagination ball. Also, it verifies about interference and collision between NC equipment and workpiece, as it applied machine simulation to NC Data of actuality aircraft parts of BULKHEAD and FRAME. As the result of this study, by removing the equipment interference and collision element which creates NC data, the virtual machine tool it the efficiency of machine process has increased.
Research on Machineability in NURBS Interpolator Considering Constant Material Removal Rate
Ko Tae Jo ; Kim Hee Sul ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 60~66
Increasing demands on precision machining of 3D free-form surface have necessitated the tool to move smoothly with varying feedrate. To this regard, parametric interpolators such as NURBS (Non-Uniform Rational B-Spline) interpolator have been introduced in CNC machining system. Such interpolators reduce the data burden in NC code, increase data transfer rate into NC controller, and finally give smooth motion while machining. In this research, a new concept to control cutting load in NURBS Interpolator was tried based on the curvature of curve. This is to protect cutting tool, and to have good machinability. For proof of the system, cutting force and surface topography were evaluated. From the experimental results. the interpolator is good enough for machining a free-form surface.
The Finite Element Analysis and the Geometric Optimal Design of Linear Motor
Lee Tae Won ; Jung Jae Han ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 67~74
Linear motor has been considered to be the most suitable electric machine for high speed and high precision linear motion control. Thrust of linear motor is one of the important factor to specify motor performance. Maximum thrust can be obtained by increasing the current in conductor and is relative to the sizes of conductor and magnet. But, the current and the size of conductor have an effect on temperature of linear motor. Therefore, it is practically important to find design results that can effectively maximize the thrust of linear motor within limited range of temperature. Finite element analysis was applied to calculate thrust and numerical solutions were compared with experiment. The temperature of the conductor was calculated by the thermal resistance which was measured by experiment. The optimum design process was coded by the ADPL of ANSYS which is a commercial finite element analysis software. Design variables and constraints were chosen based on manufacturing feasibility and existing products. As a result, it is shown that temperature of linear motor plays an important role in determining optimum design.
Development of the Fault Diagnostic System on the Rotating Machinery Using Vibration Signal
Lee Choong-Hwi ; Sim Hyoun Jin ; Oh Jae-Eung ; Yoon Lee Jng ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 75~83
With the rotating machinery getting more accurate and diversified, the necessity fur an appropriate diagnosis technique and maintenance system has been greatly recognized. However, until now, the operator has executed a monitoring of the machine by the senses or simple the change of RMS (root mean Square) value. So, the diagnostic expert system using the fuzzy inference which the operator can judge easily and expertly a condition of the machine is developed through this study. In this paper, the hardware and software of the diagnostic expert system was composed and the identification of the diagnostic performance of the developed system for 5 fault phenomena was carried out.
The Welding Process Control Using Neural Network Algorithm
Cho Man Ho ; Yang Sang Min ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 84~91
A CCD camera with a laser stripe was applied to realize the automatic weld seam tracking in GMAW. It takes relatively long time to process image on-line control using the basic Hough transformation, but it has a tendency of robustness over the noises such as spatter and arc tight. For this reason, it was complemented with adaptive Hough transformation to have an on-line processing ability for scanning specific weld points. The adaptive Hough transformation was used to extract laser stripes and to obtain specific weld points. The 3-dimensional information obtained from the vision system made it possible to generate the weld torch path and to obtain the information such as width and depth of weld line. In this study, a neural network based on the generalized delta rule algorithm was adapted for the process control of GMA, such as welding speed, arc voltage and wire feeding speed.
Development of Defect Inspection System for PDP ITO Patterned Glass
Song Jun Yeob ; Park Hwa Young ; Kim Hyun Jong ; Jung Yeon Wook ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 92~99
The formation degree of sustain (ITO pattern) decides quality of PDP (Plasma Display Panel). For this reason, it makes efforts in searching defects more than 30 un as 100%. Now, the existing inspection is dependent upon naked eye or microscope in off-line PDP manufacturing process. In this study developed prototype inspection system of PDP 170 glass is based on line-scan mechanism. Developed system creates information that detects and sorts kinds of defect automatically. Designed inspection technology adopts multi-vision method by slip-beam formation for the minimum of inspection time and detection algorithm is embodied in detection ability of developed system. Designed algorithm had to make good use of kernel matrix that draws up an approach to geometry. A characteristic of defects, as pin hole, substance, protrusion, are extracted from blob analysis method. Defects, as open, short, spots and et al, are distinguished by line type inspection algorithm. In experiment, we could have ensured ability of inspection that can be detected with reliability of up to 95% in about 60 seconds.
Feature Recognition for Digitizing Path Generation in Reverse Engineering
Kim Seung Hyun ; Kim Jae Hyun ; Park Jung Whan ; Ko Tae Jo ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 100~108
In reverse engineering, data acquisition methodology can generally be categorized into contacting and non-contacting types. Recently, researches on hybrid or sensor fusion of the two types have been increasing. In addition, efficient construction of a geometric model from the measurement data is required, where considerable amount of user interaction to classify and localize regions of interest is inevitable. Our research focuses on the classification of each bounded region into a pre-defined feature shape fer a hybrid measuring scheme, where the overall procedures are described as fellows. Firstly, the physical model is digitized by a non-contacting laser scanner which rapidly provides cloud-of-points data. Secondly, the overall digitized data are approximated to a z-map model. Each bounding curve of a region of interest (featured area) can be 1.aced out based on our previous research. Then each confined area is systematically classified into one of the pre-defined feature types such as floor, wall, strip or volume, followed by a more accurate measuring step via a contacting probe. Assigned to each feature is a specific digitizing path topology which may reflect its own geometric character. The research can play an important role in minimizing user interaction at the stage of digitizing path planning.
A Methodology on Treating Uncertainty of LCI Data using Monte Carlo Simulation
Park Ji-Hyung ; Seo Kwang-Kyu ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 109~118
Life cycle assessment (LCA) usually involves some uncertainty. These uncertainties are generally divided in two categories such lack of data and data inaccuracy in life cycle inventory (LCI). This paper explo.es a methodology on dealing with uncertainty due to lack of data in LCI. In order to treat uncertainty of LCI data, a model for data uncertainty is proposed. The model works with probabilistic curves as inputs and with Monte Carlo Simulation techniques to propagate uncertainty. The probabilistic curves were derived from the results of survey in expert network and Monte Carlo Simulation was performed using the derived probabilistic curves. The results of Monte Carlo Simulation were verified by statistical test. The proposed approach should serve as a guide to improve data quality and deal with uncertainty of LCI data in LCA projects
Study on the Torque Calculation of Touch Free Gear Using Permanent Magnet
Boo Kwangsuck ; Choi Young ; Yeo Hongtae ; Lee Jongil ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 119~126
Permanent magnetic gears are magneto-mechanical devices that are widely used to replace the ordinary mechanical gear and to transmit torque without the mechanical contact. This study investigates the characteristics of touch free permanent magnetic gear according to the employing systems. The effect of the magnetic torque is analyzed by using 3 dimensional Finite Element Method (FEM). To estimate the transmission torque of FEM model, the numerical results are compared with the experimental results. The influences of geometry size, magnet number on transmission torque are obtained. As results of this paper, it is confirmed that the transmission torque behavior is associated with the configuration of the magnet numbers and the air gap between the two permanent magnetic gears.
Fundamental Study on Mechanism of Strip Pinching in Rolling
Lee Chang Woo ; Shin Kee Hyun ; Hong Wan Kee ; Jung Dong Taek ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 127~132
It is very important to find out causes of strip pinching for the high quality of products and fer the stable operation of rolling system. We have examined the strip pinching from three points of view to find out the causes of strip pinching in rolling system: strip shape, rolling operation conditions, and behavior of strip. Wedge, off center, and difference of rolling force through CMD(Cross machine direction) are found to possibly provide major initial causes of strip pinching. Generally strip pinching occurred in the tail of strip. Thus, computer simulations by using a FEM code were also carried out to find out the initial mechanism of strip pinching depending upon the force and geometric boundary conditions at the time of strip tail rolling. The strong compression force effect due to the sudden release of strip tail from the work roll and non-uniform strip tail shape (ex. Fish tail) across the CMD were found to provide possible major causes of strip pinching.
Calculation of Contact Pressure to the Die of Axisymmetric Extrusion by Using Upper Bound Solution
Choi Young ; Yeo Hong-Tae ; Hur Kwando ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 133~139
In general, the contact pressure to the die cannot be easily determined by using upper bound solution. Recently, the authors have proposed the method determining the contact pressure with the upper bound solution for the forming with the plane stain plastic deformation. In this paper, the method is applied to an axisymmetric forward extrusion process. The contact pressure to the die of the axisymmetric extrusion has been determined with the upper bound solution and compared with the result of rigid plastic FEM. The optimal semi-angles of die have been obtained minimizing the relative contact pressure to die fur the extrusion ratio.
Design of Butterfly Valve Disk to Minimize Interference at Opening and Closing
Choi Young ; Boo Kwangsuk ; Yeo Hong-Tae ; Hur Kwando ; Kim Hokwan ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 140~145
In this study, the design and analysis of a butterfly valve disk was performed to minimize the rubbing between the disk and the seat at opening and closing. The butterfly valve has double eccentric structure and the contact surface between the disk and the seat is a conical surface. At the instant of opening and closing the valve by the rotation of disk, the positions of zero contact point are changed. Also, if the cone surface is cut in the perpendicular direction to the rotation axis of the valve, the contour of cutting section is hyperbolic. Therefore minimum distance between the origin of the eccentric axis and the hyperbolic curve goes to the position of zero contact point. In order to consider the interferences between the disk and the seat, the thermal-structure coupled field analysis was performed by ANSYS.
Fatigue Characteristics of SM490A Welded Joints for Bogie Frame
Park Jae Sil ; Seok Chang Sung ; Koo Jae Mean ; Shin Jae Ho ; Goo Byeong Choon ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 146~153
We compared the fatigue characteristics of weld metal with those of base metal, and not heat-treated with heat-treated. Also, we examined the influence of bead in a viewpoint of fatigue life. From the experimental results, it has been seen that the fatigue characteristics of welded specimens grinded the toe of bead are slightly better than not grinded. We have seen that the fatigue life is affected more by the stress concentration on the profile change in the weld toe rather than by residual stress influence, because heat-treated or not had almost no influence on the fatigue characteristics.
A Study on the Improvement of Form Accuracy Using the Length Strain of Rapid Prototype
Kim Tae Ho ; Park Jae Duk ; Kim Min Ju ; Lee Seung-Soo ; Lee Jun Hee ; Jeon Eon-Chan ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 154~159
This study is aimed to diminish the errors which created during transforming from 3D shape created with CAD program to STL file formation. The length strain which created on X-Y axises at STL file transforming is diminished by using the relation between common shape error and shrinkage rate. As the result of study, we have confirmed the length strain in accordance with facetres value. Also, the shape error is compensated with shrinkage rate by error of length strain. so, we could diminish to shape error by several tens micrometer.
Micromachining Thin Film Using Femtosecond Laser Photo Patterning Of Organic Self-Assembled Monolayers.
Choi Moojin ; Chang Wonseok ; Kim Jaegu ; Cho Sunghak ; Whang Kyunghyun ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 160~166
Self-Assembled Monolayers(SAMs) by alkanethiol adsorption to thin metal film are widely being investigated fer applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecule and bio molecule. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance of Self-Assembled Monolayers in selective etching of thin metal film. In this report, we present the several machining method to form the nanoscale structure by Mask-Less laser patterning using alknanethiolate Self-Assembled Monolayers such as thin metal film etching and heterogeneous SAMs structure formation.
Effect of Contact Area on Friction and Wear Behavior in Atomic Force Microscope
Choi Dukhyun ; Hwang Woonbong ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 167~173
Recently, it has been reported that frictional behavior at nanometer scale can be different from that at macro scale. In this article, friction and wear tests were conducted using an AFM to investigate the effect of real contact area on the coefficient of friction and wear property. SiO
, Hica, and SiGe were used in friction test and the AFM tip was Si
. The real contact area between an AFM tip and flat surface was calculated by the Johnson-Kendall-Roberts (JKR) theory. Wear specimen was Mica, and the diamond tip was used. We found that the coefficient of friction is constant below a critical area, but it is degraded over the area. Moreover, it is found that wear depth increased rapidly from a certain load and was degraded as a function of the number of the scanning cycles. Also, the range of scanning velocity used in this study had little effect on the wear depth.
A Study on Design and Manufacture of an Inchworm Linear Motor System
Ye Sang Don ; Jeong Jae Hoon ; Min Byeong Hyeon ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 174~181
Ultra precision positioning mechanism has widely been used on semiconductor manufacturing equipments, optical spectrum analyzer and cell manipulations. Ultra precision positioning mechanism is consisted of several actuators, sensors, guides and control systems. Its efficiency depends on each performance of components. The object of this study is to design, analysis and manufacture all of the inchworm linear motor system, which is one of the equipments embodied in ultra precision positioning mechanism. Inchworm linear motor system is consisted of a controller system and an inchworm linear motor, and its driving form is similar to a motion of spanworm. A design and manufacture of inchworm linear motor, which is consisted of three PZT actuators, a rod, two columns and a guide plate, are performed. Minimizing the von-Mises stress of the hinge using Taguchi method and simulation by FEM software optimizes the structural design in a column of flexure hinge. The designed columns and guide plates are manufactured by a W-EDM and NC-milling. A controller system, which is an apparatus to drive inchworm linear motor, can easily adjust driving conditions by varying resonance frequency and input-output voltage of actuators and amplifiers. The performance of manufactured inchworm linear motor system is verified and valuated. In the future, inchworm linear motor system will be used to make a more precision positioning by reinforcing a sensor and feedback system.
A Study on the Development of Child Human Model for Crashworthiness Analysis
Kim Heon Young ; Kim Sang Bum ; Kim Joon Sik ; Lee In Hyeok ; Lee Jin Hee ;
Journal of the Korean Society for Precision Engineering, volume 21, issue 12, 2004, Pages 182~191
This study is focused on the development of a child human model, which is composed of skin, skeleton, joints and muscle, etc. The dimension of child outer skin is referred to anthropometric data from KRISS (Korea Research Institute of Standards and Science). The positions of joint and mass properties of body segments are calculated from ATB(Articulated Total Body) program, GEBOD. The properties of bones and muscles are obtained by the way of scaling from adult human model. To verify the developed human model, ROM simulation and sled test is conducted. Developed human model can be effectively applied to the evaluation of human injury in crash situation and development of child restraint system. The explicit finite element program
was used to simulate six-year old child human model.