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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
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
Development of Internet-Based Rapid Prototyping Machine
Choi, T. ; Song, Y. ; Park, S. ; Kang, S. ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 11~18
Interned-based Expert System for Machine Tool Diagnosis
Kang, Mujin ; Seo, Dong-Kyu ; Kang, Dae-Chon ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 19~25
Web-Based Remote Control System Using Power Line Communication
Cha, Joo-Heon ; Jeoun, Hee-Yeoun ; Kim, Jae-Doc ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 26~32
Remote Monitoring, Remote Fault Diagnosis, and Remote Operation for Manufacturing Devices
Kim, Sun-Ho ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 33~44
Control of Robot System on the Elastic Base by Approximate Jacobian Operators
Lee, Sun ; Lee, Ho-Gil ; Hwang, Sung-Ho ; Rhee, Sehun ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 45~52
This paper presents a study on the position tracking control of a robot system on the uncertain elastic base. The elastic bathe is a nonholonomic system but it can be changed into holonomic system, which is much easier to analyze, by modeling an elastic base as a virtual robot that has passive joints. Also, Jacobian operators, which represent the overall robot system including base movement, are defined and applied to the changed model. However, because base movements are not known, the exact Jacobian operators can＇t be estimated. The control algorithm proposed is that uses only Jacobians of a real robot as approximate Jacobian operators. Therefore the approximate Jacobian operators compensate the measured errors from external sensors. The proposed control strategy is evaluated by the simulation and experiment of a single-axis robot system on the elastic base.
The Elastic Contact Analysis of 3D Rough Surface of Nongaussian Height Distribution
Kim, Tae-Wan ; Koo, Young-Pil ; Cho, Yong-Joo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 53~60
Surface roughness plays a significant role in friction, wear, and lubrication in machine components. Most engineering surfaces have the nongaussian height distribution. So, in this study, contact simulations are conducted for not only gaussian surfaces but also nongaussian surfaces. Nongaussian rough surface considering the kurtosis is generated numerically And the effects of kurtosis on real contact area fraction, average gap, and mean asperity contact pressure are studied. It will be shown that the real contact area fraction and the mean asperity contact pressure are sensitive to the characteristics of surface geometry according to kurtosis.
A Study on Failure Analysis of Low Pressure Turbine Blade in Nuclear Plant using AFM
Hong, Soon-Hyeok ; Choi, Woo-Sung ; Moon, Sung-Jun ; Cho, Seok-Swoo ; Joo, Won-Sik ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 61~68
Turbine blade in nuclear plant is subject to cyclic bending fatigue by high steam pressure. Especially, fatigue fracture is caused by low stress below yielding stress. Photograph by SEM doesn't have striation but photograph by AFM has striation on the fatigue fractured surface of 12% Cr steel used in turbine blade. Surface roughness
has the linear relation with respect to stress intensity factor range ΔK and is increased linearly according to load amplitude
. In this study loading condition applied to turbine blade is predicted by the relation between the gradient of
and load amplitude
A Requirements Driven System Design Process for a Small System
Kim, Eui-Jung ; Shin, Keun-Ha ; Choi, Jae-Sung ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 69~75
Systems engineering has been utilized in system development primarily for large-scale projects or commercial large-scale systems during the last several decades. We can understand why it would be useful to apply systems engineering to the development of a relatively small system. However, it is difficult to effectively carry out a project due to the complexity in applying the methods of systems engineering. To apply systems engineering to the development of a small system, the system engineering processes should be tailored. We established a requirements driven system design process(RDSDP) that can effectively carry out the system design far a small system. RDSDP is a system design process that treats all the requirements thoroughly and effectively. This is applied by the designer according to a standardized and systematized process during the first phase in design, in which system specifications are made. By using RDSDP, we can affect a reduction of the number of redesign phases in the process of the system design, shorten the period for to make specification, which will then cause the system to succeed in the actual application.
Forming Characterististics of Radial-Backward Extrusion for Single Action Pressing
Jang, Dong-Hwan ; Ko, Beong-Du ; Lee, Yeong-Sub ; Hwang, Beong-Bok ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 76~83
This paper is concerned with the analysis of the forming characteristics of radial-backward extrusion. The single action pressing is analyzed by using the rigid-plastic FEM. The design factors such as die corner radius, gap height, and friction factor are involved in the simulation. The analysis is focused on the influences of the design factors on the maximum punch farce and metal flow into can and flange region. As a result of analysis, the gap height among the design factors is known to have a major effect on the metal flow of radial-backward extrusion for single action pressing compared with other design factors. As is expected, forming load and volume of flange increase as gap height and die corner radius increase, respectively.
A Study on the Measurement of Load Torque by the Field Coil Current in an Eddy Current Dynamometer
Mun, Byung-Su ; Lee, Eung-Suk ; Lee, Hyung-Seok ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 84~92
Commercial eddy current dynamometers control the torque of rotating body, power supply machine, with the field coil current being operated as a braking force. In this paper, we studied the relation between field coil current and torque load of eddy current dynamometer. By the torque measuring analysis of eddy current dynamometer it is linear relation between the brake force measured from a torque meter which is installed at the case of dynamometer and the multiplied shaft rpm by the squares of field coil current (N
). To prove the relation, it was experimented and showed that the torque operated by the rotating body can be measured with the shaft rpm and the field coil current of the eddy current dynamometer. This result shows a possibility that eddy current dynamometer can measure the torque of rotating body without a torque measuring device. such as load cell.
Analysis and Control of a 3-Phase VR Type Self-Bearing Step Motor for Small Angle Control Considered the fringing Effect
Kim, Daegon ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 93~100
The analysis and control of a new type unsymmetrical slotted self-bearing step motor for small angle control is presented. The motor actuator is used for both motor and bearing functionality without any additional coil windings or electromagnets for bearing functionality. A circular-arc, straight-line permeance model for the fringing effect is presented. An unsymmetrical slotted self-bearing step motor layout and control algorithm are described. A new control current generation method using the electromagnets layout geometry, which needs no additional current for bearing functionality, is proposed. As the result of this analysis the fringing effect largely influences on the system characteristics. especially in torque. Even if the bearing functionality is added into the motor functionality, it is shown that the magnitude of torque is not changed.
A Study on the Modeling and Diagnostics on Chatter in Endmilling Operation
Kim, Young-Kook ; Yoon, Moon-Chul ; Ha, Man-Kyeong ; Sim, Seong-Bo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 101~108
In this study, the static and dynamic characteristics of endmilling process were modelled and the analytic realization of chatter mechanism was discussed. In this reward, We have discussed on the comparative assessment of recursive time series modeling algorithms that cal represent time machining process and detect the abnormal machining behaviors in precision endmilling operation. In this study, simulation and experimental works were performed to show the malfunctional behaviors. For this purpose, new recursive algorithm(RLSM) was adopted for the oil-line system identification and monitoring of a machining process, we can apply these new algorithms in real process for detection of abnormal chatter. Also, The stability lobe of chatter was analysed by varying parameter of cutting dynamics in regenerative chatter mechanics.
Fracture Mechanics Analysis of Multiple Load Path Plate
Han, Moon-Sik ; Lee, Yang-Sub ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 109~115
The compliance approach to the problem of load sharing between a cracked plate and multiple plate used to bridge the crack. The theory is validated by using calculated stress intensity factors for the multiple load path plate to reduce experimentally observed growth rate to a common base. Calculations are them made on the effect of multiple load path plate width on fatigue crack retardation in order to demonstrate the predictive capability of the technique.
Obstacle-Free Optimal Motions of a Manipulator Arm Using Penetration Growth Distance
Park, Jong-Keun ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 116~126
This paper suggests a numerical method to find optimal geometric path and minimum-time motion for a spatial 6-link manipulator arm (PUMA 560 type). To find a minimum-time motion, the optimal geometric paths minimizing 2 different dynamic performance indices are searched first, and the minimum-time motions are searched on these optimal paths. In the algorithm to find optimal geometric paths, the objective functions (performance indices) are selected to minimize joint velocities, actuator forces or the combinations of them as well as to avoid one static obstacle. In the minimum-time algorithm the traveling time is expressed by the power series including 21 terms. The coefficients of the series are obtained using nonlinear programming to minimize the total traveling time subject to the constraints of velocity-dependent actuator forces.
Analysis of the Characteristics of ASMS Hydraulic Modulator (Automotive Stability Management System)
Song, Chang-Seop ; Kim, Hyoung-Tae ; Shin, Sang-Won ; Jeong, Tae-Chun ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 127~133
In this study, the effect of the factors of a hydraulic modulator of ASMS was analysed. The modeling of ASMS was presented and the equation of ASMS was derived from the modeling. With this background, GUI analysis tool was developed. After the verification of the reasonability of simulation, the response of a hydraulic modulator is investigated through simulation of modeling. With this simulation, each behavior was predicted with changing the various parameters and determined the influenced factors to apply the designing process.
Numerical Simulation considering Latent Heat Effect for Laser Cladding Process
Zhao, Guiping ; Si, Ho-Mun ; Jo, Jong-Du ; Kim, Jae-Do ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 134~147
Laser cladding process accompanies phase transformations from melting (on heating) through solidifying (on cooling) at the same time within a small material volume and to final solid phase. The phase transformations are not reversible, but an irreversible thermodynamic process; they accompany either absorption or release of thermal energy (referred to latent heat) during transformation. Yet, most analyses on materials processed by laser as a heat source have been performed on models of neglecting the latent heat in the process and those did not Justify the simplification. With literatures on the laser material process, we have not place an answer to how little the assumption affects on analyses. This led us to our current study: the effects of latent heat on thermo-mechanical analysis. To this end, we developed a fairly accurate program accommodating an algorithm for enforcing the latent heat whenever necessary and ran it combining with ABAQUS
. The simulation techniques we used in this study were verified by directly comparing our prediction with experimental publications elsewhere; our numerical results agreed accurately with the experiments. On the effects of the latent heat, we performed two alternatives about considering the latent heat in analysis, and compared each other. As a result, we found that more accurate conclusions might come out when considering the latent heat in process analyses.s.
Hybrid Vibration Control of Smart Laminated Composite Beams using Piezoelectric and Viscoelastic Material
Kang, Young-Kyu ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 148~153
Active control of flexural vibrations of smart laminated composite beams has been carried out using piezoceramic sensor/actuator and viscoelastic material. The beams with passive constrained layer damping hale been analyzed by formulating the equations of motion through the use of extended Hamilton's principle. The dynamic characteristics such as damping ratio and modal damping of the beam are calculated for various fiber orientations by means of iterative complex eigensolution method. This paper addresses a design strategy of laminated composite under flexural vibrations to design structure with maximum possible damping capacity.
Application of Probabilistic Fracture Mechanics Technique Using Monte Carlo Simulation
Lee, Joon-Seong ; Kwak, Sang-Log ; Kim, Young-Jin ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 154~160
For major structural components periodic inspections and integrity assessments are needed for the safety. However, many flaws are undetectable because sampling inspection is carried out during in-service inspection. Probabilistic integrity assessment is applied to take into consideration of uncertainty and variance of input parameters arise due to material properties and undetectable cracks. This paper describes a Probabilistic Fracture Mechanics(PFM) analysis based on the Monte Carlo(MC) algorithms. Taking a number of sampling data of probabilistic variables such as fracture toughness value, crack depth and aspect ratio of an initial surface crack, a MC simulation of failure judgement of samples is performed. for the verification of this analysis, a comparison study of the PFM analysis using a commercial code, mathematical method is carried out and a good agreement was observed between those results.
Design of Optimal Idle Speed Controller by Sliding Mode Observer
Lee, Young-Choon ; Lee, Seong-Cheol ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 161~167
This paper presents an approach to nonlinear engine idle controller and intake manifold absolute pressure(MAP) observer based on mean torque production model. A stable engine idle speed is important in that the unstable engine Idle mode can make engine to drooping or stall state. A sliding fuzzy controller has been designed to control engine idle speed under load disturbance. A sliding observer is also developed to estimate the intake manifold absolute pressure and compared with the actual MAP sensor value. The sliding mode observer has shown good robustness and good tracking performance. The inputs of sliding fuzzy controller are the errors of rpm and MAP. The output is a duty cycle(DC) for driving a idle speed control valve(ISCV).
Study on Application of Reverse Engineering by Generation of the Free-Form Surface
Hur, Sung-Min ; Choi, Jae-Won ; Lee, Seok-Hee ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 168~177
Reverse engineering has been widely used for the shape reconstruction of an object without CAD data and the measurement of clay or wood models fur the development of new products. To generate a surface from measured points by a laser scanner, typical steps include the scanning of a clay or wood model, the generation of compatible input curves, the generation of a surface and manufacturing data like G code or STL file. A laser scanner has a great potential to get geometrical data of a model for its frost measuring speed and higher precision. The data from a laser scanner are composed of many line stripes of points including small spikes and noise. A new approach using automated surface generating algorithm is introduced to deal with problems during reverse engineering process. And the input data and the generated surface are represented in IGES format, thus can be supplied to other CAD/CAM software without any data manipulation.
Micro Grooving of Glass Using Micro Abrasive Jet Machining
Choi, Jong-Soon ; Park, Keong-Ho ; Park, Dong-Sam ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 178~183
Abrasive jet machining(AJM) process is similar to the sand blasting and effectively removes hard and brittle materials. AJM has applied to rough working such as debarring and rough finishing. As the need for machining of ceramics, semiconductor, electronic devices and LCD are increasing, micro AJM is developed, and has become the inevitable technique to micromachining. This paper describes the performance of the micro AJM in micro grooving of glass. Diameter of hole and width of line in grooving is 80
. Experimental results showed good performance in micro grooving of glass, but the size of machined groove increased about 2~4
. With the fine tuning of masking process and compensation of film wear. this micro AJM could be effectively applied to the micro machining of semiconductor, electronic devices and LCD.
Development of Torque Monitoring System of Induction Spindle Motor using Graphic-programming
Lee, In-Hwan ; Kwon, Won-Tae ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 184~193
In vector control technique, stator currents of an induction motor are transformed to equivalent d-q currents in a reference frame consist of d and q axis, each of which is coincide with flux and torque direction respectively. Since the current in q-axis is related to the torque in a synchronously rotating frame, torque is estimated as a function of q-axis current and flux. In this paper, a method to estimate torque of an induction motor based on the measurement of 3-phase currents and rotating velocity of a rotor is presented. Graphic-programming is used to measure signals, to estimate the torque and to show the result in the form of user friendly graph in window environment. To stabilize the fluctuation of estimated torque caused from the small measurement error of the rotor velocity, the stator current is reconstructed in a program based on measured signals. The experimental results executed under the velocity of 500 rpm, 1500 rpm without load and 1500 rpm with load show that the proposed method estimates the torque very well.
Experimental Study on the Movement of Pneumatic Actuating Mechanism for Self-Propelling Endoscope
Lim, Young-Mo ; Park, Ji-Sang ; Kim, Byung-Kyu ; Park, Jong-Oh ; Kim, Soo-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 194~199
In this paper, we propose a new locomotive mechanism using impulsive force for microcapsule-type endoscope. It has the compact size for movement in the colon and actuating mechanisms for hi-directional movement. The actuating mechanism resembles a pneumatic cylinder and consists of body, inertia mass(piston). spring. pneumatic source and calve. When valve is ON, the pneumatic impulsive force between piston and body drives them in two opposite direction. As the air in the body is passed away, the contrary movements are occurred by spring reaction. Therefore, the direction of body's motion is determined by the relative magnitude of two opposite impulsive forces, i.e., pneumatic and spring force. The effect of two impulsive forces can simply be controlled by On-Off time of solenoid valve.
Study on Mechanism of Burr Formation in Drilling
Lee, Jing-Koo ; Ko, Sung-Lim ; Ko, Dae-Cheol ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 200~207
Burrs farmed in drilling are classified into three types, no burr, burrs with cap, teared burr. To control burr size in drilling, the second type burrs with cap are to be formed because it is small and uniform. It is necessary to understand the mechanism of cap formation to derive the burr formation into second type burr with cap. In several materials. second type burrs are formed in drilling by changing cutting conditions. It is observed that cap is formed as a result of the plastic deformation along the outside of exit hope. According to the tension behavior of the material in concentrated region between hole and drill outside edge, the geometry of burr with cap is determined. Simplified 2D FEM analysis shows good prediction for burr formation.
Development of Monitoring System for Super High-Speed Machining and Evaluation of Machinability of Difficult-to-cut Material
Lee, Woo-Young ; Choi, Seong-Joo ; Lee, Sang-Tae ; Kim, Heung-Bae ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 10, 2001, Pages 208~213
High speed milling(HSM) is one of the emerging cutting process having tremendous potential not only in increased metal removal rates but also in improved surface finish, burr free edge, dimensional accuracy and a virtually stress free component after machining. The High efficiency and accuracy in machining of die/mold materials can be obtained in high speed machining, so it is necessary to analytic the mechanism of high speed cutting process : cutting force, acoustic emission signal.