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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
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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
Mechanical Property Measurement in Nano Imprint Process
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 7~14
Measurement of Thin Film Thickness of Patterned Samples Using Spectral Imaging Ellipsometry
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 15~21
Nuclear Magnetic Resonance of Carbon Nanotube and Boron Nitride Nanotube
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 22~27
Machinability in Oblique Powder Blasting of Glass
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 28~34
The old technique of sandblasting which has been used for decoration of glass surface has recently been developed into a powder blasting technique for brittle materials such as glass, silicon and ceramics, capable of producing micro structures larger than 100
. In this study, we introduced oblique powder blasting, and investigated the effect of the impacting angle of particles, the scanning times and the stand-off distance on the surface roughness and the weight-loss rate of samples with no mask, and the wall profile and overetching of samples with different mask pattern in powder blasting of soda-lime glass. The varying parameters were the different impact angles between 50
, scanning times of nozzle up to 40 and the stand-off distances 70mm and 100mm. The widths of mask pattern were 0.2mm, 0.5mm and 1mm. The powder was alumina sharp particles, WA #600. The mass flow rate of powder during the erosion test was fixed constant at 175g/min and the blasting pressure of powder at 0.2Mpa.
Development and Evaluation of the Characteristics of Porous Materials for a Mold
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 35~42
At the large-sized mold fer injection molding, the remaining gas in the mold causes some problems with final products. In order to solve these problems, air-bent was drilled on the surface of mold. However, this method leaves the scar on the surface of a product. Therefore, porous material was developed to the removal of remaining gas in this study. Porcerax II, which is a commercialized porous material, were developed in USA. It requires the electric discharge machining(EDM) process to make pores on the surface of the materials. The electric discharge machining (EDM) process, however, cause the increase of the time and cost for the fabrication of the mold. In this study, high speed machining(HSM) process was applied to the fabrication of porous mold without electric discharge machining(EDM) process. Some characteristics of the developed materials machined by high speed machining(HSM) and electric discharge machining(EDM) including air-permeability and porosity were compared with those of Porcerax II. Besides, in order to be applied to the molding process, hardness and tensile ＆ yield strength were compared between Porcerax II and developed materials.
Form Error Prediction in Side Wall Milling Considering Tool Deflection
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 43~51
A method for form error prediction in side wall machining with a flat end mill is suggested. Form error is predicted directly from the tool deflection without surface generation by cutting edge locus with time simulation. Developed model can predict the surface form error about three hundred times faster than the previous method. Cutting forces and tool deflection are calculated considering tool geometry, tool setting error and machine tool stiffness. The characteristics and the difference of generated surface shape in up milling and down milling are discussed. The usefulness of the presented method is verified from a set of experiments under various cutting conditions generally used in die and mold manufacturing. This study contributes to real time surface shape estimation and cutting process planning for the improvement of form accuracy.
Analysis of Working Factors for Improvement of Surface Roughness on High Speed End-Milling
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 52~59
Recently the high speed end-milling processing is demanded the high-precise technique with good surface roughness and rapid time in aircraft, automobile part and molding industry. The working factors of high speed end-milling has an effect on surface roughness of cutting surface. Therefore this study was carried out to analyze the working factors to get the optimum surface roughness by design of experiment. From this study, surface roughness have an much effect according to priority on distance of cut, feed rate, revolution of spindle and depth of cut. By design of experiment, it is effectively represented shape characteristics of surface roughness in high speed end-milling. And determination(
) coefficient of regression equation had a satisfactory reliability of 76.3% and regression equation of surface roughness is made by regression analysis.
A Study on Reverse Engineering and 5-axis NC Machining of Impeller
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 60~68
This paper presents a method fur impeller modeling and 5-axis machining by the reverse engineering. The impeller is composed of pressure surface, suction surface and leading edge, and so on. The surfaces can be modeled by using the characteristic curves such as hub curves, shroud curves and fillet curves. The characteristic curves are extracted from the scanned data and the inspection is performed between the surfaces generated by using the characteristic curves and the scanned data. Then, An impeller is machined by 5-axis mainlining and post-processing with inverse kinematic solution.
Prediction Model of Aerosol Generation for Cutting Fluid in Turning
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 69~76
This paper presents a prediction model for the aerosol generation of cutting fluid in turning process. Experimental studies have been carried out in order to identify the characteristics of aerosol generation in non-cutting and cutting cases. The indices of aerosol generation was mass concentration comparable to number generation, which is generally used fur environment criterion. Based on the experimental data, empirical model for predicting aerosol mass concentration of cutting fluid could be obtained by a statistical analysis. This relation shows good agreement with experimental data.
A Study on the Optimal Cutting Condition of High Speed Feeding Type Laser Cutting Machine by Taguchi Method
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 77~83
Cutting by a high speed laser cutting machine is one of most effective technologies to improve productivity. This paper has studied to obtain the cutting characteristics and optimal cutting conditions in a high speed feeding type laser cutting machine by Tacuchi method in design of experiments. A Lf(34) orthogonal array is adopted to study the effect of adjustment parameter. The adjustment parameters consist of cutting speed, laser power, laser output duty and assistant gas pressure. And the quality feature is selected as surface roughness of sheet metal. Variance analysis is performed in order to evaluate the effect of adjustment parameters on the quality feature of laser cutting process.
A Study on the Performance Improvement and Simplification of the Modulator for Vehicle Stability Control System
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 84~93
This study carries out the performance improvement and simplification of hydraulic modulator that plays an important role in vehicle stability control systems. The mathematical models for each component of a modulator, such as pump, wheel cylinder, check and solenoid valve, accumulator, damper are derived in detail. All the mathematical models are combined to form a modulator system and implemented through a computer program, which can be controlled by a user friendly GUI. To verity the simulation, comparison between simulation and experiments has been made. After the verification of the validity of the simulation, the effects of the design parameters of the modulator on the wheel cylinder pressure is investigated. The results show that the modulator without MPA has advantage in early time pressure rise rate, and it can be simplified.
Estimation of Specular Light Power by Adjusting Incident Laser Power for Measuring Mirror-Like Surface Roughness
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 94~101
From the Beckmann's reflection model of wave incident, reflected light from a surface is known to have not only specular but also diffuse components. The specular component dominant a surface for a mirror-like surface is distributed on the almost the same area as the spot on the surface, but the diffuse component region dominant f3r a rough surface spreads scattered on the larger areas than the spot. Therefore, statistic parameters from the scattered light distribution are more meaningful in the diffuse region, while the magnitude of rather meaning in the specular region. In usual, there need two sensors to acquire two kinds of information: Photo-detector for light intensity magnitude and image sensor for light intensity distribution. But dual sensor scheme requires a beam splitter usually to feed light to each sensor, and moreover there is not a combination rule to relieve the different sensor characteristics. In this study a new method is proposed for acquisition of the dual information using only an image sensor. Specular region is established on an image area being distinguished from a diffuse component, and laser power is adjusted so that no pixel of the image sensor in the specular region is saturated. Simulation based on the light reflection theory and the experimental results are quite well matched, and thus the proposed method was proved to be very useful for mirror-like surface measurement.
An Experimental Investigation on The Contamination Sensitivity of An Automotive Fuel Pump
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 102~108
This study addresses the contamination sensitivity test of a typical fuel pump for automotive vehicle. The objective of the study is to find the contamination sensitivity coefficient of fuel pump on specific contaminant particle sizes so that optimal fuel filter could be selected. To achieve the objective, the degradation of discharge flow rate of fuel pump was measured under the experiments of various contaminants size ranges of ISO test dust up to 80
. The fundamental theory of contamination sensitivity was introduced and the contamination sensitivity coefficients were estimated using the experimental data. Maximum contamination sensitivity coefficient of
L/minㆍEa was found on the contaminant size range of 40
. The magnified picture of the surface of vane disc revealed that the abrasive wear was the principal cause of discharge flow rate degradation. Hence, this study revealed that high efficiency filter on the contaminant particle size range of 30
especially should be used to maintain the service lift of the fuel filter.
Effects by Applying Mode of Single Overload on Propagation Behavior of Fatigue Crack
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 109~116
In this study, when variable-amplitude load with various applying mode acts on the pre-crack tip, we examined how fatigue cracks behave. Hence aspects of the deformation caused by changing the applying mode of single overload and propagation behavior of fatigue crack were experimentally examined: What kinds of the deformation would be formed at pre-crack and its tip\ulcorner What aspects of the residual plastic deformation field would be formed in front of a crack\ulcorner How aspects of the plastic zone could be evaluated\ulcorner As applying mode of single overloading changes, the deformation caused by tensile and shear loading variously showed in each applying mode. The different aspects of deformation make influence on propagation behavior of cracks under constant-amplitude fatigue loading after overloading with various modes. We tried to examine the relationship between aspects of deformation and fatigue behavior by comparing the observed deformation at crack and crack propagation behavior obtained from fatigue tests.
Filling Imbalance in 3 Plate Type Injection Molds with Multi-Cavity
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 117~121
Injection molding is the one of the most important processes for mass production of plastic parts. Usually injection molds for mass production are constituted to multi-cavity runner system to manufacture the more parts at a time. Multi-cavity molds are designed to geometrically balanced runner system to uniformly fill to each cavity. But, when injection molding is performed using a mold with balanced runner system filling imbalances are occurred between the cavity to cavity. The previous studies by Beaumont at. all reported that filling imbalance occurred by thermal unbalance on the mold and viscosity variation of resins and so on. In this study, we conducted experiments in order to know the causes of filling imbalance for 3 plate type mold with 8 cavities. And we exhibited a new so called 4BF mold (4 plate type Balanced Filling Mold) to be possible filling balance. We conducted a experimental injection molding to verify the efficiency of the 4BF mold. In the results of the experiment, we could confirmed the balanced filling possibility of the 4BF mold.
Dynamic Deformation Behavior of Rubber and Ethylene Copolymer Under High Strain Rate Compressive Loading
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 122~130
It is well known that a specific experimental method, the Split Hopkinson Pressure Bar (SHPB) technique is a best experimental technique to determine the dynamic material properties under the impact compressive loading conditions with strain-rate of the order of 10
/s. This type of experimental procedure has been widely used with proper modification on the test setups to determine the varying dynamic response of materials for the dynamic boundary conditions such as tensile and fracture as well. In this paper, dynamic compressive deformation behaviors of a rubber and an Ethylene Copolymer materials widely used for the isolation of vibration from varying structures under dynamic loading are estimated using a Split Hopkinson Pressure Bar technique.
Optimization of Pin-hole Location to Minimize Stress Concentration around Hole in Rotating Disc under Centrifugal Force
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 131~138
The objective of this paper is to decide optimal location of a pin-hole to minimize stress concentration around the hole in a rotating disc. The focus of this investigation is to evaluate the effect of pin-hole on stress distribution around the hole using optimum design technique and finite element analysis. Design variables are the radial and the angular location of pin-hole from center of the hole and objective function is the maximum stress around hole in a rotating disc. Using first order method of optimization technique, we found that the maximum equivalent stress around the hole with optimized pin-hole could be reduced by 15.1% compared to that without pin-hole.
Development of a Hydrostatic Guideway Driven by the Linear Motor
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 139~144
In order to discuss the availability of hydrostatic guideways driven by the coreless linear motor to ultra precision machine tools, a prototype of guideway is designed and tested in this research. A coreless linear DC motor with the continuous force of 156 N and a laser scale with the resolution of 0.01
are used as the feeding system. The experiments are performed on the static stuffiness, motion accuracy, positioning accuracy, microstep response and variation of velocity. The guideway has the infinite axial stillness within 50 N of applied load, and by the motion error compensation method using the Active Controlled Capillary, 0.08
of linear motion error and 0.1 arcsec of angular motion error are acquired. The guideway also has 0.21
of positioning error and 0.09
of repeatability, and it shows the stable response against the 0.01
resolution step command. The velocity variation of feeding system is less than 0.6 %. From these results, it is confirmed that the hydrostatic guideway driven by the coreless linear motor is very useful fur the ultra precision machine tools.
A Study on Determination of the Area Function of Nano Indenter Tip with AFM
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 145~152
Depth-sensing indentation is wifely used for evaluation of mechanical properties of thin films. It is generally accepted that the most significant source of uncertainty in nanoindentation measurement is the geometry of the indenter tip. Therefore the successful application of the technique requires accurate calibration of the indenter tip geometry. The direct measurement of geometry of a Berkovich indenter was determined using a atomic force microscope. The indentation geometrical calibration of contact area was performed by analyzing the indenter tip profile. The equations of area functions were proposed for nanoscale thin films..
Directly Nano-precision Feature Patterning on Thin Metal Layer using Top-down Building Approach in nRP Process
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 153~159
In this study, a new process to pattern directly on a thin metal layer using improved nano replication printing (nRP) process is suggested to evaluate the possibilities of fabricating a stamp for nano-imprinting. In the nRP process, any figure can be replicated from a bitmap figure file in the range of several micrometers with nano-scaled details. In the process, liquid-state resins are polymerized by two-photon absorption which is induced by femto-second laser. A thin gold layer was sputtered on a glass plate and then, designed patterns or figures were developed on the gold layer by newly developed top-down building approach. Generally, stamps fur nano-imprinting have been fabricated by using the costly electron-beam lithography process combined with a reactive ion-etching process. Through this study, the effectiveness of the improved nRP process is evaluated to make a stamp with the resolution of around 200nm with reduced cost.
Development of Contour Offset Algorithm(COA) in nRP Process for Fabricating Nano-precision Features
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 160~166
In this study, a new algorithm, named as Contour Offset Algorithm(COA) is developed to fabricate precise features or patterns in the range of several micrometers by nano replication printing(nRP) process. In the nRP process, a femto-second laser is scanned on a photosensitive monomer resin in order to induce polymerization of the liquid monomer according to a voxel matrix which is transformed from the bitmap format file. After polymerization, a droplet of ethanol is dropped to remove the unnecessary remaining liquid resin and then only the polymerized figures with nano-scaled precision are remaining on the glass plate. To obtain more precise replicated features, the contour lines in voxel matrix should be modified considering a voxel size. In this study, the efficiency of the proposed method is shown through two examples in view of accuracy.
The Length Control of Carbon Nanotube using Electrochemical Etching
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 167~171
In this paper, we proposed a new method to control the length of carbon nanotube using electrochemical etching. We made a nano probe that was composed of the tungsten tip and multi-wall carbon nanotube. The nano probe was placed on the nano stage and the carbon nanotube on the nano probe was etched in the electrolyte solution with the applied voltage. The overall procedures were done under optical microscope and can be monitored. We can obtain a nano probe with proper length through this procedure.
WC Micro-shaft Fabrication Using Electrochemical Etching
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 172~178
Tungsten carbide microshaft can be used as various micro-tools for MEMS because it has high hardness and high rigidity. In this study, experiments are performed to produce tungsten carbide micro-shaft using electrochemical etching. H
solution is used as electrolyte because it can dissolve tungsten and cobalt simultaneously. Optimal electrolyte concentration and machining voltage satisfying uniform shape, good surface quality, and high MRR of workpiece are experimentally found. By controlling the various machining parameters, a straight micro-shaft with 5
diameter, 3 mm length, and 0.2
taper angle was obtained.
A Safety Assessment by Risk Analysis Method on Wheelchair Occupant in Frontal ＆ Side Impact of Wheelchair Loaded Vehicle
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 179~187
In this study, for a safety assessment of wheelchair occupant in frontal and side impact of wheelchair loaded vehicle, a sled impact test was perfumed. Each test was carried out total 6 times, by using Hybrid III 50th-percentile male dummy in light weight and electric wheelchair. We estimate MC(Motion Criteria), CIC(Combined Injury Criteria), HIC(Head Injury Criteria), HNIC(Head and Neck Injury Criteria) based on measured data. Through this study, we make an assessment of risk analysis of wheelchair occupant and wheelchair. Through this study, safety standard of wheelchair is to be evaluated.
Investigation into the Development of Technology for Orthopeadic Surgery Utilizing Reverse Engineering and Rapid Prototyping Technology
Journal of the Korean Society for Precision Engineering, volume 21, issue 6, 2004, Pages 188~196
The objective of this paper is to propose a new technology of the orthopaedic surgery using the combination of reverse engineering (RE) based on CT data and rapid prototyping (RP). The proposed technology utilizes symmetrical characteristics of the human body and capability of the combination of RE and RP, which rapidly manufactures three-dimensional parts from CT data. The original .stl data of injured extents are generated from the mirror transformation of .stl file fur uninjured extents. The physical shape before injuring is manufactured from RP using the original .stl data. Subsequently, pre-operative planning, such as a selection of proper implants, preforming of the implant, a decision of fixation locations and an insert position for the implant, an estimation of the invasive size, and pre-education of operators are performed using the physical shape. In order to examine the applicability and the efficiency of the proposed surgical technology, various case studies, such as a distal tibia commented fracture, a proximal tibia plateau fracture and an iliac wing fracture of pelvis, are carried out. From the results of case studies, it has been shown that the proposed technology is an effective surgical tool of the orthopaedic surgery reducing the operational time, the operational cost, the radiation exposure of the patient and operators, and morbidity. In addition, the proposed technology could improve the accuracy of operation and the speed of rehabilitation.