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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 18, Issue 12 - Dec 2001
Volume 18, Issue 11 - Nov 2001
Volume 18, Issue 10 - Oct 2001
Volume 18, Issue 9 - Sep 2001
Volume 18, Issue 8 - Aug 2001
Volume 18, Issue 7 - Jul 2001
Volume 18, Issue 6 - Jun 2001
Volume 18, Issue 5 - May 2001
Volume 18, Issue 4 - Apr 2001
Volume 18, Issue 3 - Mar 2001
Volume 18, Issue 2 - Feb 2001
Volume 18, Issue 1 - Jan 2001
Selecting the target year
Environmental Friendly Machining Process Technology Using Compressed Cold Air
Choi, Heon-Zong ; Lee, Seok-Woo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 11~17
Technology of Environmentally Conscious Machining for Ultra-precision Lapping with In-Process Electrolytic Dressing
Lee, Eun-Sang ; Choe, Jae-Young ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 18~24
Eco-process in a Semiconductor Manufacturing Process
Jeong, Hae-Do ; Kim, Ho-Youn ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 25~30
Environment-friendly Cutting Process Technology
Lee, Jong-Hang ; Lee, Sang-Jo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 31~36
Ultrasonic Simulation for Test Condition Estimate
Huh, Sun-Chul ; Park, Young-Chul ; Lee, Kwang-Young ; Park, Won-Jo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 37~44
Ultrasonic testing has a characteristics such as excellent permeability, high-sensitivity to find defect and an almost exact measurement for position. size and direction of inner defect, which differ from other non-destructive testing. In the study, we developed program into optimal testing condition, to distinguish obstacle echo and defect position. This program shows generation and processing of ultrasonic pulse. We compared simulation with ultrasonic test in 45
transducer. Test results were in accordance with simulation within 0.1~7.2%.
Control of Automatic Cargo Handling System Using ER Valves (I) -Modeling of ER Valves-
Sung, Kum-Kil ; Chung, Dar-Do ; Choi, Seung-Bok ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 45~52
This paper presents two different models of electrorheological(ER) valves which can be applicable to an automatic cargo handling system at the seaport. Four different ER fluids, which are commercially available, are adopted and their Bingham characteristics are experimentally evaluated with respect to the intensity of electric field. The field-dependent Bingham models are used in the design of two types of ER valves; single-type and divided-type. The governing equations of motion of the ER valves are derived and the principal design parameters are determined based on 200ton platform to be vertically controlled by the ER valves. Both pressure drops due to the applied field and current density required to operate the ER valves are analyzed. In addition, the pressure drops of the cylinder system are evaluated for both ER valves.
Control of Automatic Cargo Handling System Using ER Valves (II) -Modeling and Control of Cargo Handling System-
Sung, Kum-Kil ; Chung, Dar-Do ; Choi, Seung-Bok ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 53~60
This paper presents a position control of a platform at the seaport cargo handling system. After brief description of the operating principles of the cargo handling system, the governing equation of the moving platform is derived. The equation is described in the state space model, and a robust H
controller to achieve position tracking of the moving platform. which can carry 200ton of containers, is formulated. In the synthesis of the controller, the weight of the container is treated as uncertain parameter. Both regulating and tracking control responses are analyzed for the loading and unloading procedures of the proposed automatic cargo handling system.
Efficient Digitizing in Reverse Engineering By Sensor Fusion
Park, Young-Kun ; Ko, Tae-Jo ; Kim, Hrr-Sool ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 61~70
This paper introduces a new digitization method with sensor fusion for shape measurement in reverse engineering. Digitization can be classified into contact and non-contact type according to the measurement devices. Important thing in digitization is speed and accuracy. The former is excellent in speed and the latter is good for accuracy. Sensor fusion in digitization intends to incorporate the merits of both types so that the system can be automatized. Firstly, non-contact sensor with vision system acquires coarse 3D point data rapidly. This process is needed to identify and loco]ice the object located at unknown position on the table. Secondly, accurate 3D point data can be automatically obtained using scanning probe based on the previously measured coarse 3D point data. In the research, a great number of measuring points of equi-distance were instructed along the line acquired by the vision system. Finally, the digitized 3D point data are approximated to the rational B-spline surface equation, and the free-formed surface information can be transferred to a commercial CAD/CAM system via IGES translation in order to machine the modeled geometric shape.
Active Noise Transmission Control Through a Panel Structure Using a Frequency Domain Identification Method
Kim, Yeung-Shik ; Kim, In-Soo ; Moon, Chan-Young ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 71~81
This paper analyzes the effectiveness of minimizing vibration and sound transmission on/through a thin rectangular plate by both feedback control and hybrid control which combines adaptive feedforward control with a feedback loop. An experimental system identification technique using the matrix-fractional curve-fitting of the frequency response data is introduced for complex shaped structures. This identification technique reduces the model order o the MIMO(Multi-Input Multi-Output) system which simplifies the practical implementation. The adaptive feedforward control uses a Multiple filtered-x LMS(Least Mean Square) algorithm and the feedback control uses a multivariable digital LQG(Linear Quadratic Gaussian) algorithm. Experimental results show that an effective reduction of sound transmission is achieved by the hybrid control scheme when both vibration and noise measurement signals are incorporated in the controller.
Cutting Characteristics of SiC-based Ceramic Cutting Tools Part 1: Microstructure and Mechanical Properties of SiC-based Ceramic Cutting Tools
Park, June-Seuk ; Kim, Kyeug-Jae ; Shim, Wan-Hee ; Kwon, Won-Tae ; Kim, Young-Wook ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 82~88
In order to fulfil the requirements of the various performance profiles of ceramic cutting tools, six different SiC-based ceramics have been fabricated by hot-pressing (SiC--
composites) or by hot-pressing and subsequent annealing (monolithic SiC and SiC-TiC composites). Correlation between the annealing time and the corresponding microstructure and the mechanical properties of resulting ceramics have been investigated. The grain size of both
and SiC in SiC-
composites increased with the annealing time. Monolithic SiC has the highest hardness, SiC-TiC composite the highest toughness, and the SiC-
composite the highest strength among the ceramics investigated. The hardness of SiC-
composites was relatively independent of the grain size, but dependent on the sintered density. The cutting performance of the newly developed SiC-based ceramic cutting tools will be described in Part 2 of this paper.
Cutting Characteristics of SiC-based Ceramic Cutting Tools Part 2 : Tool Life and Cutting Force Characteristics of SiC-based Ceramic Cutting Tools
Park, June-Seuk ; Kim, Kyeug-Jae ; Kwon, Won-Tae ; Kim, Young-Wook ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 89~95
Ceramic tool has to equip with not only high toughness and strength but also low thermal expansion and good thermal conductivity which leads to the high thermal shock resistance. These characteristics make it have longer tool life under thermal stress condition. In this study, commercial Si
ceramic cutting tool and home-made SiC based ceramic cutting tools which have different sintering time and chemical composition are tested under various cutting speed and the feed rate increase, the cutting force and the flank wear growth ratio increase, too. The performance of home-made SiC based ceramic cutting tool shows the possibility to be a new ceramic tool.
Investigation of Flying Characteristics of Slider with Micro-actuator
Moon, Jae-Taek ; Chung, Koo-Hyun ; Kim, Dae-Eun ; Jeon, Jong-Up ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 96~100
As the track density of hard disk drives increases, there is a need for more precise actuation of the head. This can be accomplished by using a high band width micro-actuator. In this work, the flying characteristics of sliders with micro-actuators are investigated with the aim to optimize the head/disk interface performance of such sliders. Contact-start-stop, sweep, and flying height tests are performed and analyzed. The results show that the MEMS based micro-actuator mounted on a slider possess acceptable flying characteristics.
Numerical Simulationof Plaster Casting with Pressurized Vibration
Kim, Gi-Don ; Yang, Dong-Yeol ; Jeong, Jun-Ho ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 101~109
The simulated die casting process in which the traditional plaster casting process is combined with rapid prototyping technology is being used to produce Al, Mg and Zn die casting prototypes. Because of lower mechanical properties induced by the large grain structure and incomplete filling, conventional plaster casting is not suitable for the simulated die casting process. A plaster casting process with pressurized vibration was developed for the simulated die casting process. In this paper, numerical simulation for the filling stage of the process has been performed to show the effect of the pressurized vibration for complete filling. Treatment of boundary condition based on the finite element method has been proposed for imparted pressurized vibration in the plaster casting process.
Process Design of the Hot Pipe Bending Process Using High Frequency Induction Heating
Ryu, Gyeong-Hui ; Lee, Dong-Ju ; Kim, Dong-Jin ; Kim, Byeong-Min ; Kim, Gwang-Ho ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 110~121
During hot pipe bending using induction heating, the wall of bending outside is thinned by tensile stress. In design requirement, the reduction of wall thickness is not allowed to exceed 12.5%. So in this study, two methods of bending, one is loading of reverse moment and the other is loading of temperature gradient, have been investigated to design pipe bending process that satisfy design requirements. For this purpose, finite element analysis with a bending radius 2Do(outer diameter of pipe) has been performed to calculate proper reverse moment and temperature gradient to be applied. Induction heating process has been analyzed to estimate influence of heating process parameters on heating characteristic by finite difference method. Then pipe bending experiments have been performed for verification of finite element and finite difference analysis results. Experimental results are in good agreement with the results of simulations.
고주파 표면경화에 의한 피로강도 특성과 예측에 관한 연구
Song, Sam-Hong ; Choi, Byoug-Ho ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 122~130
Induction surface hardening is widely used to enhance local strength and hardness. However, most research is only to have a focus on fatigue life and fatigue behavior is not so much studied. So, in this study, Cr-Mo steel alloy(SCM440) was used to show the effect of residual stress and micro hole on the fatigue strength fur base metal and induction surface hardened specimen. In addition, the fatigue characteristic between surface hardened and fully hardened steel is somewhat different. It is caused by hardness distribution, residual stress and inclusions etc.. The modification of prediction equation of fatigue strength is proposed and predicted results show very good accuracy. A
, which is calculated 1.46, is introduced to consider the effect of stationary crack with defect. A new method of modifying residual stress is proposed to examine the mean stress effect under fatigue loading.
Fatigue Crack Propagation Behavior in STS304 under Mixed Mode Loading
Song, Sam-Hong ; Lee, Jeong-Moo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 131~139
The use of fracture mechanics has traditionally concentrated on crack growth under an opening mechanism. However, many service failure occur from cracks subjected to mixed mode loadings. Hence, it is necessary to evaluate the fatigue behavior under mixed mode loading. Under mixed mode loading conditions, not only the fatigue crack propagation rate is of importance, but also the crack propagation direction. The mode I and II stress intensity factors of CTS specimen were calculated using elastic finite element method. The propagation behavior of the fatigue crack of the STS304 steeds under mixed mode loading condition was evacuated by using stress intensity factors
. The MTS criterion and effective stress intensity factor were applied to predict the crack propagation direction and the fatigue crack propagation rate.
Finite Element Analysis for Performance Evaluation of the Seal in a Universal Joint Bearing
Kim, Tae-Wan ; Moon, Suk-Man ; Koo, Young-Pil ; Cho, Yong-Joo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 140~146
Seals in a universal joint bearing are important components reinforcing lubrication performance by holding lubricant and preventing infiltration of dust, moisture, etc.. There is a great difference in seal performance according to seal shape and bonding position. Therefore, in this study, as for both the lip type seal and the O-ring type seal, FE analysis is conducted using Mooned-Rivlin Model. The results show that O-ring type seal does not have any effect of misalignment angle compared with lib type seal, which is more profitable.
Displacement-Type Web Position Control of Cold Mills Using QFT
Jeong, Jae-Hyo ; Kim, Jong-Sik ; Park, Jeon-Soo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 147~155
A new displacement type web position control system for cold mills using QFT is presented. The control system features an inner-outer cascaded system in which the inner loop provides the position tracking control of the hydraulic system and the outer loop provides the position regulation control of the web. By the sensitivity analysis and computer simulation, it is verified that the proposed control system has better robust stability and performance than the conventional control system.
Process Analysis for Rheology Forming Considering Flow and Solidification Phenomena in Lower Solid Fraction
Jung, Young-Jin ; Cho, Ho-Sang ; Kang, Chung-Gil ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 156~164
Two-dimensional solidification analysis during rheology forming process of semi-solid aluminum alloy has been studied. Two-phase fluid flow model to investigate the velocity field and temperature distribution is proposed. The proposed mathematical model is applied to the die shape of the two types. To calculate the velocity and temperature fields during rheology forming process, the earth governing equation correspondent to the liquid and solid region are adapted. Therefore, each numerical models considering the solid and liquid region existing within the semi-solid material have been developed to predict the deflect of rheology forming gnarls. The Arbitrary Boundary Maker And Cell (ABMAC) method is employed to solve the two-phase flow model of the Navier-Stokes equation. Theoretical model on the basis of the two-phase flow model is the mixture rule of solid and liquid phases. This approach is based on the liquid and solid viscosity. The liquid viscosity is pure liquid state value, however solid viscosity is considered as a function of the shear rate, solid fraction and power law curves.
Experiments on the Grinding Conditions for Helical Scan Grinding of a Glass Material
Lee, Dae-Uk ; O, Chang-Jin ; Lee, Eung-Seok ; Kim, Ok-Hyeon ; Kim, Seong-Cheong ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 165~170
In normal grinding abrasive particles of a grinding wheel rotate on planes parallel to the direction of workpiece fred. which may induce continued scratch lines on ground surface as the workpiece feeds. Instead in helical scan grinding the planes make an angle, called a helical angle, with the feeding direction. Thus scratch lines produced by abrasive particles per one revolution are discontinued which implies that the generation of scratch lines are suppressed by the helical scan grinding. In this study some experimental works have been done on the helical scan grinding of glass to find the effects of grinding conditions on the surface roughness and estimate the optimal grinding conditions. The helical angle, fred rate, material removal rate and the wheel speed are taken as factors for three kinds of grinding wheels i.e., coarse(#140 mesh), medium(#400) and fine(#800) diamond wheels. The experiments are scheduled by Taguchi technique and ANOVA has been carried out for the interpretation of the results. As a result of this study effects of the factors are verified quantitatively showing that the major factors are changed according to the wheel's mesh size and the helical angle is one of the influencing factors on the surface quality.
Measurement and Compensation of Nonlinearity in Homodyne Interferometer
Kim, Jong-Yun ; Eom, Tae-Bong ; Jeong, Kyu-Won ; Choi, Tae-Young ; Lee, Keon-Hee ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 171~178
The nonlinearity of a laser interferometer usually ranges from sub-nanometer to several manometers. This nonlinearity, which has periodic characteristics, limits the accuracy of the interferometer at the sub-nanometer level. The nonlinearity error of the one-frequency homodyne interferometer with quadrature fringe detection results from a number of factors including polarization mixing by imperfect optical elements, unequal gain of photo detectors, lack of quadrature between two signals and misalignment. In this paper, we described a method for measuring and compensating the nonlinearity of homodyne interferometer using the elliptical fitting technique with least-square method. Experimental results demonstrate that
3.5 nm nonlinearity can be reduced to
0.2 nm level.
A Study on the Vision Sensor System for Tracking the I-Butt Weld Joints
Bae, Hee-Soo ; Kim, Jae-Woong ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 179~185
In this study, a visual sensor system for weld seam tracking the I-butt weld joints in GMA welding was constructed. The sensor system consists of a CCD camera, a diode laser with a cylindrical lens and a band-pass-filter to overcome the degrading of image due to spatters and arc light. In order to obtain the enhanced image, quantitative relationship between laser intensity and iris number was investigated. Throughout the repeated experiments, the shutter speed was set at 1-milisecond for minimizing the effect of spatters on the image, and therefore most of the spatter trace in the image have been found to be reduced. Region of interest was defined from the entire image and gray level of searched laser line was compared to that of weld line. The differences between these gray levels lead to spot the position of weld joint using central difference method. The results showed that, as long as weld line was within
from the longitudinal straight fine, the system constructed in this study could track the weld line successful1y. Since the processing time reduced to 0.05 sec, it is expected that the developed method could be adopted to high speed welding such as laser welding.
Springback Reduction of Multi-step Cylindrical Cup in Spinning Process.
Park, Joong-Eon ; Lee, Woo-Young ; Choi, Seogou ; Kim, Seung-Soo ; Na, Kyoung-Hoan ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 186~191
Spinning process is a chipless metal forming method for axi-symmetric parts, which is more economical, efficient and versatile method for producing parts than the other sheet metal forming process such as stamping or deep drawing. In this study, a fundamental experiment was conducted to improve productivity with process parameters such as tool path, angle of roller holder(
), feed rate(
) and corner radius of forming roller(Rr). These factors were selected as variables in the experiment because they were most likely expected to hale an effect on spring back. The empirical results were analyzed to know how much spring back was affected by these factors. And also thickness and diameter distribution of a multistage cup obtained by spinning process were observed and compared with those of a commercial product produced by conventional deep drawing.
Intelligent Design System for Gate and Runner in Injection Molding
Lee, Chan-Woo ; Huh, Yong-Jeong ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 192~203
The design of gate and runner(delivery system) is one of the most important subject in injection molding. Delivery system is a channel to flow the polymer melt from the injection molding machine to the mold cavities. Also, delivery system affect quality and productivity of the part. The synthesis of delivery system of injection molding has been done empirically, since it requires profound knowledge about the moldability and causal effects on the properties of the part, which are not available to designers through the current CAD systems. GATEWAY is a knowledge module which contains knowledge to permit non-experts as well as mold design experts to generate the acceptable geometries of gate and runner far injection molded parts. A knowledge-based CAD system is constructed by adding the knowledge module, GATEWAY, to an existing geometric modeler. A knowledge-based CAD system is a new tool which enables the concurrent design and CIM with integrated and balanced design decisions at the initial design of injection molding.
Analytical Model Improvement of Automotive Muffler using the Experimental Results of Transmission Loss
Jung, Jin-Nyon ; Kim, Won-Jin ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 9, 2001, Pages 204~209
The finite element model for automotive muffler analysis is improved by modifying the boundary condition of outlet and the mesh of finite element model. The model minimizes the difference between transmission loss from analysis and that from experiment. Four different boundary conditions and the four types of finite element model are tested to find out the best one of those. From the case study it is verified that the bevel of transmission loss can be changed by the variation of radiation impedance value. Also the resonance or anti-resonance frequencies of transmission loss can be shifted by the variation of finite element mesh. An improved finite element model of muffler is proposed in consideration with the accuracy and the computing time of analysis.