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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 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
Meso-Measurement Technology and Its Industrial Importance
Kim, Seung-Woo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 9~11
Control, Instrumentation, and Communication Technologies in ITS
Choi, Jae-Weon ; Lee, Suk ; Lee, Man-Hyung ; Park, Un-Sik ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 12~20
Backgrounds and Methods for Design for Environment
Kang, Mu-Jin ; Hwang, Oh-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 21~28
Mechanical Characteristics of Rubber Mount and Vehicle Noise-Vibration Design
Kim, Gi-Se ; Lee, Eok-Seop ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 29~37
Technical Trend in Worldwide Machine Tools Industry for 21th Century
Park, Jong-Kwon ; Song, Chang-Kyu ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 38~43
A Study on Development of Program for an Automated Thixoforming Process Design
Kim, Nam-Seok ; Jeong, Hong-Gyu ; Gang, Chung-Gil ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 44~55
The flow behavior of semi-solid materials (SSM) is required to assist the industrial application of thixoforming technology. Particularly, to reduce many lead times, many numerical analysis packages have been developed to simulate required metal forming processes. The objectives of the development of SEMI-FORM for thixoforming process design are to predict the effect of various process variables such as pressing force, die temperature, and die velocity. However, there have not been any reports which adapt these packages to the specific characteristics of SSM. SO, this paper presents an overview of the development of thixoforming simulator of SEMI-FORM. The solver and post-processor of SEMI-FORM S/W for an automated thixoforming process design with arbitrarily shaped die are composed of FORTRAN Power Station 4.0 and Visual Basic 5.0, respectively. This developing SEMI-FORM S/W would be very useful for thixoforming practitioners and engineers to select the optimal process conditions to produce automotive parts with high quality.
Skyhook Control of a Semi-Active ER Damper
Lee, Yuk-Hyeong ; Park, Myeong-Gwan ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 56~62
In this paper, skyhook control of a semi-active ER(Electro-Rheological) damper is investigated. The strength of the ER damper is controlled by a high voltage power supply. This paper deals with a two-degree-of-freedom suspension using the damper with ERF for a quarter vehicle system. The control law for semi-active suspensions modeled in this study is developed using skyhook and Linear Quadratic Regulator(LQR) optimal control method. Computer simulation and experimental results show that the semi-active suspension with ERF damper has good performances of ride quality.
A Process Planning System for Machining of Dies for Auto-Body Production(II)-Operation Planning and NC Code Post-Processing
Sin, Dong-Mok ; Lee, Chang-Ho ; Choi, Jae-Jin ; Noh, Sang-Do ; Lee, Ki-Woo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 63~73
This paper presents a process and operation planning system with an NC code post-processor for effective machining of press dies for production of cars. Based on the machining features, major parts of press dies are categorized into 15 groups and a standard process plan is defined for each group. The standard process plan consists of a series of processes where a process is defined as a group of operations that can be done with one setup. Details such as cutting tools, cutting conditions, and tool paths are decided at the operation planning stage. At the final stage of process and operation planning, the NC code post-processor we developed adjusts feedrates along the tool path to reduce machining time. The adjustment rule is selected based on the metal removal rate estimated by virtually machining with virtual cutting tool.
An Experimental Study on Dynamic Pressure Characteristics in the Cylinder Bore of Oil Hydraulic Axial Piston Pump
Kim, Jong-Gi ; Jeong, Seok-Hun ; Jeong, Jae-Yeon ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 74~81
Dynamic pressure is one of the major sources on noise emission in oil hydraulic piston pump. This paper reports an experimental study of dynamic pressure characteristics in the cylinder bore of oil hydraulic piston pump. We experimently measured dynamic pressure at BDC with delivery pressure, rotational speed and oil temperature. Because the V-grooves at the ends of the kidney ports with three types valve plates. We hope this paper help to design of the valve plate in oil hydraulic piston pump.
Design Parameters of Optical Pickup Actuator for the Next Generation
Han, Chang-Soo ; Kim, Soo-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 82~88
The demands of high data transfer rate and high recording density in optical disk memory device are being increased. In this paper, 4 design parameters for next generation optical disk are investigated. As for the high data transfer rate, two design parameters such as driving acceleration and transmissibility are introduced. As the high recording density is concerned, the minimum linearity and the tilt of the actuator are introduced. Two kinds of pickup actuator are used to evaluate the validity of the parameters through the simulation and the experiment. The 4-wire actuator has good linearity but bad stability and tilt characteristics, while the rotary and axis actuator has good stability for the external vibration but bad linearity. It is demonstrated that the newly proposed design parameters are available to design and evaluate quantitatively the performance of the actuator for the next generation optical disk.
Performance Analysis of a Vibrating Microgyroscope using Angular Rate Dynamic Model
Hong, Yoon-Shik ; Lee, Jong-Hyun ; Kim, Soo-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 89~97
A microgyroscope, which vibrates in two orthogonal axes on the substrate plane, is designed and fabricated. The shuttle mass of the vibrating gyroscope consists of two parts. The one is outer shuttle mass which vibrates in driving mode guided by four folded springs attached to anchors. And the other is inner shuttle mass which vibrates in driving mode as the outer frame does and also can vibrate in sensing mode guided by four folded springs attached to the outer shuttle mass. Due to the directions of vibrating mode, it is possible to fabricate the gyroscope with simplified process by using polysilicon on insulator structure. Fabrication processes of the microgyroscope are composed of anisotropic silicon etching by RIE, gas-phase etching (GPE) of the buried sacrificial oxide layer, metal electrode formation. An eletromechanical model of the vibrating microgyroscope was modeled and bandwidth characteristics of the gyroscope operates at DC 4V and AC 0.1V in a vacuum chamber of 100mtorr. The detection circuit consists of a discrete sense amplifier and a noise canceling circuit. Using the evaluated electromechanical model, an operating condition for high performance of the gyroscope is obtained.
Development of Feature-based Encapsulation Process using Filler Material
Choe, Du-Seon ; Lee, Su-Hong ; Sin, Bo-Seong ; Yun, Gyeong-Gu ; Hwang, Gyeong-Hyeon ; Lee, Ho-Yeong ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 98~103
Machining is the commonly used process in the manufacturing of prototypes. This process offers several advantages, such as rigidity of the machine, precision of the machine, precision of the operation and specially a quick delivery. The weight and immobility of the machine support and immobilize the part during the operation. However, despite these advantages it shows, machining still presents several limitations. The immobilization, location and support of the part are referred to as fixturing or workholding and present the biggest challenge for time efficient machining. So it is important to select and design the appropriate fixturing assembly. This assembly depends on the complexity of the part and the tool paths and may require the construction of dedicated fixtures. With traditional techniques, the range of fixturable shapes is limited and the identification of suitable fixtures in a given setup involves complex reasoning. To solve this limitation and to apply the automation, this paper presents the Reference Free Part Encapsulation(RFPE) and implementation of the encapsulation system. The feature-based modeling system and the encapsulation system are implemented. The small part of which it is difficult to find out the appropriate fixturing assembly is made by this system.
Rapid Product Fabrication using Wire Welding with CO2 Laser Irradiation and Milling Process Technology
Choi, Du-Seon ; Lee, Su-Hong ; Sin, Bo-Seong ; Yun, Gyeong-Gu ; Hwang, Gyeong-Hyeon ; Park, Jin-Yong ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 104~110
The rapid prototyping and tooling technology has been developed. However, most commercial ones currently use resins or waxes as the raw materials. These days, the direct metal deposition methods are being investigated as new rapid prototyping and tooling technology. A fundamental study on rapid prototyping and tooling with wire welding technology using CO2 laser radiation was carried out in this paper. The main focus is to develop a simple commercial rapid prototyping and tooling system with the exiting laser welding technology as output and their microstructure, hardness and tensile strength are examined for the reliability. In addition, its advantages and disadvantages are discussed as a rapid prototyping and tooling system.
Failure-Proof Design of the PCB of a Monitor Using Deformed Mode Shape
Park, Sang-Hu ; Lee, Bu-Yun ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 111~116
A practical scheme to reduce failure of the PCB(Printed Circuit Board) of a monitor is introduced using deformed mode shape under mechanical shock. When the monitor is given critical shock loads, cracks are commonly initiated at the tip of a hole on the PCB. Accordingly, a deformed mode shape of the PCB is obtained using a FEM code to define a weak point on the PCB under mechanical shock, and then the position and direction of the hole is determined to prevent the failure at the critical mode shape. Also, the stress intensity factor around the weak point on the PCB is calculated to check the possibility of fracture by normal tensile stress. In conclusion, present research is useful to assist the practical design of components-layout on the PCB.
Development of a Channel Cutting Die Set
Park, Kuwi-Sun ; Lee, Choon-Man ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 117~122
Many kinds of channels are used in industrial equipment and production machinery. Although mechanical saw has been used to cut many sorts of channels, there is cost rise problem because of low productivity. Shearing of channel has a special place because it helps to cut expected shape and size easily. A channel cutting die set which can be mounted and used on a hydraulic press is developed to improve the productivity of channel cutting process. Mode for the channel cutting is divided into single cut and double cut method. This study use double cut method, and the developed channel cutting die set is composed of upper and lower die set. Shearing time can be reduced from 40 minutes to 20 seconds using the developed channel cutting die set. The productivity of channel cutting process can be increased with shearing time reduction as well as cost reduction.
A Study on the Inlet NOx Estimation of SCR System in a Refuse Incineration Plant by Using General Structured Observer
Lee, Chung-Hwan ; Kim, In-Gyu ; Kim, Hwan-Seong ; Kim, Sang-Bong ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 123~128
The function of SCR system in refuse incineration plant is to reduce the harmful combustion gases especially NOx which make serious environmental pollution. The SCR system normally have a NOx measurement system such as inlet NOx analyzer and outlet T.M.S.(Tele Monitoring System) to control the outlet NOx in stack. The NOx measurement system is very important, however there are frequently happened sensing problems and it need maintenance periodically. In this paper, we propose an estimation method of inlet NOx of SCR system by using general structured observer. The inlet NOx is considered as an input disturbance and it is modelled by applying FFT method in frequency domains. Through the design of general structured observer, the outlet NOx can be estimated by using observation error between real outlet NOx and estimated outlet NOx. The effectiveness of the proposed method is shown by comparing to a measured inlet NOx data.
The Effects of the Annealing Heat Treatments on the Mechanical Properties of the Invar Materials
Won, Si-Tae ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 129~138
This study examined the effects of the annealing heat treatments on the mechanical properties of the Invar(Fe-36%Ni Alloy) materials. Invar materials were annealed at various temperatures range 900~120
in vacuum(10-4Torr) and hydrogen atmospheres. And annealing conditions were changed by cooling rate and holding time at 110
. The grain size of rolled Invar materials was very fine but those of annealed Invar materials at 900~120
in vacuum and hydrogen atmosphere increased with increasing annealing temperature. The micro-vickers hardness values of annealed Invar materials were decreased about 15% that of the rolled Invar materials, regardless of the various of annealing temperatures, atmosphere(vacuum, hydrogen) and annealing conditions. The tensile strength and yield strength of annealed Invar materials at 900~120
in vacuum and hydrogen atmosphere were decreased 10.0~14.4% and 34.6~39.1% those of the rolled Invar materials, respectively. The strength ratio(tensile strength/ yield strength) of annealed Invar materials was improved to 1.7~1.8 from the value of 1.2~1.3 of rolled Invar materials. The degree of spring back of annealed Invar materials was about 50% of the rolled Invar materials, regardless of the various of annealing temperatures, atmosphere(vacuum, hydrogen) and annealing conditions.
Analysis of Laser Weldment Distortion in the EDFA LD Pump Packaging
Gang, Dae-Hyeon ; Son, Gwang-Jae ; Yang, Yeong-Su ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 139~146
This paper presents a study on heat transfer and residual distortion analysis of laser welded EDFA(Erbium Doped Fiber Amplifier) LD(Laser Diode) Pump using the finite element method. In the production process of LD Pump in light-wave communication system, ferrule and saddle are welded by Nd-YAG laser. These parts experience thermal and mechanical effect during heating and cooling cycle with the laser welding. Thus distortion happens in the laser-welded packaging, and it makes an error in detecting the light signal translate through optical fiber in LD Pump. The amount of final displacement produced by the laser welding is predicted using the finite element method. And the optimal shape of saddle is proposed with the results of numerical analyses to minimize the displacement.
Design and Development of Shaker for Acceleration test of Gimbal
Yoon, Jae-Youn ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 147~153
This paper proposes a shaker system design for acceleration test of gimbal. Main reason of shaker system design is to give acceleration to the gimbal, which is moving and tracking the target on the tracking test equipment. The shaker system is mounted on the tracking test equipment. It uses the scotch yoke mechanism to have the constant movement in return. The Scotch yoke mechanism changes the rotational movement of constant velocity to simple harmonic motion.
A UBET Analysis of Non-axisymmetric Forward and Backward Extrusion
Lee, Hee-In ; Kim, Jin-Kyu ; Hwang, Bum-Chul ; Bae, Won-Byong ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 154~161
A UBET analysis has been carried out to predict the forming load and the extruded length of forward and backward extrusion of hexagonal and trochoidal wrench colts. For the upper bound load and the average length of the extruded billets are determined by minimizing the total energy consumption rate which is a function of unknown velocities and parameters at each element. Experiments are carried out with antimony-lead billets at room temperature using hexagonal and trochoidal shaped punches. The theoretical predictions of the forming load and the extruded length are in good agreement with the experimetal results.
A Study of Arc Modeling and Heat Input Distribution on the Surface during Torch Weaving in Gas Metal Arc Welding
Kim, Yong-Jae ; Rhee, Se-Hun ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 162~170
In torch weaving in arc welding on V groove, the heat input distribution on groove surface is a main factor determining the bead shape and the weld quality with and without the weld defects such as undercut, overlap, etc. In this study, we calculate the heat input varying with the welding current, arc voltage, welding speed and the touch weaving condition using numerical method. And we investigate the heat input distribution on groove surface while applying the various grooves having 2 dimensional heat sources.
Improvement of the Robustness Bounds of the Linear Systems with Structured Uncertainties
Jo, Jang-Hyen ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 171~179
The purpose of this paper is the derivation and development of the new definitions and methods for the new estimation of robustness for the systems having structured uncertainties. This proposition adopts the theoretical analysis of the Lyapunov direct methods, that is, the sign properties of the Lyapunov function derivative integrated along finite intervals of time, in place of the original method of the sign properties of the time derivative of the Lyapunov function itself. This is the new sufficient criteria to relax the stability condition and is used to generate techniques for the robust design of control systems with structured perturbations. The systems considered are assumed to be nominally linear, with time-variant, nonlinear bounded perturbations. This new techniques demonstrate the improvement of robustness bounds from the numerical results.
PID Learning Method using Gradient Approach for Optimal Control
Lim, Yoon-Kyu ; Chung, Byeong-Mook ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 180~186
PID control is widely used in industrial areas, but it is not easy to tune PID gains for an optimal control. The proposed learning method is to tune PID gains using the gradient approach. We use two estimation functions in this method : one is an error function for tuning of PID gains, and the other is a performance measuring function for a completion of learning. This paper shows that optimal PID controllers can be acquired when this learning method is applied to 10 systems with different natural frequencies and damping ratios.
평면 연삭 가공시 발생하는 연삭열에 관한 연구 -해석적 모델-
Kim, Dong-Kil ; Nam, Weon-Woo ; Lee, Sang-Jo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 187~194
The objective of this study is to develop a model for the grinding process for predicting the temperature, thermal stress and thermal deformation. The thermal load during grinding is modeled as uniformly distributed, 2D heat source moving across the surface of elastic half space, which is insulated or subjected to convective cooling. That non-dimensional temperature distribution, non-dimensional longitudinal stress distribution and non-dimensional thermal deformation distribution are calculated with non-dimensional heat source half width and non-dimensional heat transfer coefficient. Finite element models are developed to simulate moving heat source, which is modeled as uniformly or triangularly distributed, the FEM simulation is compared with numerical solution.
공리적 설계를 이용한 초미세 발포 공정 설계
Jeong, Dae-Jin ; Cha, Sung-Woon ; Yoon, Jae-Dong ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 195~200
There is a great demand for reducing the amount of material used in mass-produced plastics parts, for material cost constitutes up to 75% of the total production cost. Plastics do not easily decay which causes environmental problem. Furthermore, material reduction therefore decreases the amount of oil needed for the manufacture of plastics and thus help conserve this natural resource. Therefore, microcellular foamed plastics(MCPs) was developed at MIT to solve these problem alternation 1980's. Until now, however, microcellular foaming process not designed systematically because the key factors governing the process were not clear. The goal of this research is to obtain the optimal design of the microcellular plastics by using axiomatic approach.
An Experimental Study on the Fatigue Behavior and Stress Interaction of Arbitrarily Located Defects (II) (For Variable Loads and Distances between Defects)
Song, Sam-Hong ; Bae, Jun-Su ; Choe, Byeong-Ho ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 1, 2001, Pages 201~212
If defects are located far apart, fatigue cracks are independently initiated from them and gradually approach other cracks so that the fatigue life becomes influenced by the crack growth behavior of those interacting cracks. In this study, the effect of the stress interaction between defects on the fatigue crack propagation behavior is investigated experimentally and these results are verified by finite element method. In addition, fatigue crack propagation behaviors under micro hole interaction field are studied.