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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 25, Issue 12 - Dec 2008
Volume 25, Issue 11 - Nov 2008
Volume 25, Issue 10 - Oct 2008
Volume 25, Issue 9 - Sep 2008
Volume 25, Issue 8 - Aug 2008
Volume 25, Issue 7 - Jul 2008
Volume 25, Issue 6 - Jun 2008
Volume 25, Issue 5 - May 2008
Volume 25, Issue 4 - Apr 2008
Volume 25, Issue 3 - Mar 2008
Volume 25, Issue 2 - Feb 2008
Volume 25, Issue 1 - Jan 2008
Selecting the target year
A Study on Development of PFC applicable to Inverter System
Kim, Tae-Woo ; Kim, Tae-Kue ; Park, Seung-Kyu ; Ahn, Ho-Kyun ; Yoon, Tae-Sung ; Kwak, Gun-Pyoung ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 7~12
A Study of Endcap Type on Ball Screw
Park, Dong-Keun ; Kim, Hyun-Ku ; Lee, Choon-Man ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 13~19
A Study on the Prediction and Measurement of Transmission Error for High Speed Gear
Son, Yu-Sun ; Bae, Hyo-Je ; Tak, Sung-Hoon ; Zhang, Qi ; Lyu, Sung-Ki ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 20~26
A Study on the Manufacture Process Parameters of Roller for Rubbing LCD-panel
Kim, Woong ; Lee, Choon-Man ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 27~32
Preform Design for Manufacturing of Automobile Drum Clutch Hub Products
Park, Joon-Hong ; Kim, Seung-Gyu ; Kang, Jung-Ho ; Park, Young-Chul ; Kim, Sung-Hwan ; Seo, Sung-Ryul ; Park, Kun-Hyung ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 33~38
Design and Development of Asymmetry Glass Array Lens
Park, Soon-Sub ; Hwang, Yeon ; Lee, Ki-Young ; Kim, Geon-Hee ; Won, Jong-Ho ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 39~46
Asymmetric glass lens core for portable projection optic system was designed and simulated. And it was machined by newly developed non-rotational ultra precision grinding method. With the designed lens data which optimized for multi-collimation, we generated the we core surface data. Mold pressing conditions analyzed by FEM. In the machining process, ground profile errors were compensated based on measured data, minimized feed rate and depth of cut. The deviations of machined core profile were acceptable level for glass mold press. Mold pressed glass array lens was coated with
Hard Turning Machinability of V30 Cemented Carbide with PCD, cBN and PcBN Cutting Tool
Heo, Sung-Jung ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 47~54
Hard turning process can be defined as a single-point machining process carried out on "hard" materials. The process is intended to replace or limit traditional grinding operations that are expensive, environmentally unfriendly, and inflexible. The purpose of this study is to achieve a systematic understanding of machining characteristics and the effects of machining parameters on cutting force, tool wear shape and chip formation by the outer cutting of a kind of wear resistant tungsten carbide V30. Hard turning experiments were carried out on this alloy using the PCD (Poly Crystalline Diamond), cBN (cubic Boron Nitride) and PcBN (Polycrystalline cubic Boron Nitride) cutting tools. The PcBN and the usual cBN tools were used to be compare with the PCD tool and the dry turning was carried out. The PcBN is attractive as the tool material which replaces the PCD. The tool wear width and cutting force were measured, and the worn tool and chip were observed. The difference of the tool wear mechanism among the three tool materials was investigated.
Development of an Automated Progressive Design System for Manufacturing Product with Multi Processes, Piercing, Bending, and Deep Drawing
Hwang, Beom-Cheol ; Kim, Chul ; Bae, Won-Byong ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 55~64
This paper describes a research work of developing an automated progressive design system for manufacturing the product with multi processes such as piercing, bending, and deep drawing. An approach to the system for progressive working is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system consists of three main modules, which are shape treatment, strip layout, and die layout modules. Based on knowledge-based rules, the system is designed considering several factors, such as material and thickness of a product, piercing, bending and deep drawing sequence, and the complexities of the blank geometry and punch profiles. It generates the strip layout drawing for an automobile product. Die design for each process is carried out through the die layout module from the results of the strip layout module. Results obtained using the modules enable the designers for manufacturing products with multi processes to be more efficient in this field.
Implementation of a Transformable Hexapod Robot for Complex Terrains
Yoo, Young-Kuk ; Kong, Jung-Shik ; Kim, Jin-Geol ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 65~74
This paper deals with the path creation for stable action of a robot and transformation by using the fuzzy algorithm. Also, the obstacle detection and environmental analysis are performed by a stereo vision device. The robot decides the range and the height using the fuzzy algorithm. Therefore the robot can be adapted in topography through a transformation by itself. In this paper, the robot is designed to have two advantages. One is the fast movability in flat topography with the use of wheels. The other is the moving capability in uneven ground by walking. It has six leg forms for a stable walk. The wheels are fixed on the legs of the robot, so that various driving is possible. The height and the width of robot can be changed variously using four joints of each leg. The wheeled joint has extra DOF for a rotation of vertical axis. So the robot is able to rotate through 360 degrees. The robot has various sensors for checking the own state. The stable action of a robot is achieved by using sensors. We verified the result of research through an experiment.
Modeling and Robust Controller Design of a Swash Plate for Swash Plate Type Variable Displacement Axial Piston Pump
Park, Sung-Hwan ; Park, Yong-Ho ; Lee, Ji-Min ; Kim, Jong-Shik ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 75~81
A robust controller is proposed for regulating effectively the pressure of control cylinder of swash plate type variable displacement axial piston pump. In order to design a precise and robust pressure control system, a mathematical model for swash plate control system is identified by the signal compression method. Based on the identified mathematical model, an
robust swash plate controller is designed which is robust to the variation of the load pressure. The precise and robust swash plate control characteristics are verified by experiments.
Sliding Mode Control for an Active Magnetic Bearing System
Kang, Min-Sig ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 82~88
This paper describes an application of sliding mode control to an active magnetic bearing(AMB) system. A sliding mode control is robust to model uncertainties and external disturbances. To ensure the authority of sliding mode control, model parameter uncertainties caused from linearization of electro-magnetic attractive force are analyzed and a domain of parameter uncertainties in which reachability to sliding surface is guaranteed is derived. The validity of the analysis is illustrated along with some simulation examples.
Robust Control for Nonlinear Friction Servo System Using Fuzzy Neural Network and Robust Friction State Observer
Han, Seong-Ik ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 89~99
In this paper, the position tracking control problem of the servo system with nonlinear dynamic friction is issued. The nonlinear dynamic friction contains a directly immeasurable friction state variable and the uncertainty caused by incomplete parameter modeling and its variations. In order to provide the efficient solution to these control problems, we propose the composite control scheme, which consists of the robust friction state observer, the FNN approximator and the approximation error estimator with sliding mode control. In first, the sliding mode controller and the robust friction state observer is designed to estimate the unknown internal state of the LuGre friction model. Next, the FNN estimator is adopted to approximate the unknown lumped friction uncertainty. Finally, the adaptive approximation error estimator is designed to compensate the approximation error of the FNN estimator. Some simulations and experiments on the servo system assembled with ball-screw and DC servo motor are presented. Results show the remarkable performance of the proposed control scheme. The robust friction state observer can successfully identify immeasurable friction state and the FNN estimator and adaptive approximation error estimator give the robustness to the proposed control scheme against the uncertainty of the friction parameters.
A Study on the Low Pressure Injection Molding of Automotive Seat-back Cover
Ko, Byung-Doo ; Ham, Kyoung-Chun ; Jang, Dong-Hwan ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 100~106
In this paper, the injection molding process of automotive seat-back cover is analyzed in terms of simulation and of experiment. FE analysis was used to obtain molding conditions such as injection pressure, filling pattern, packing, shrinkage. Vacuum system for low pressure injection molding is developed in the experiment. Low pressure injection molded parts have been compared with conventional molded parts in terms of molding quality and mechanical properties. Based on the results, good product and the productivity improvement can be obtained in low pressure injection molding for automotive seat-back cover.
Excitation Force Analysis of a Powertrain Based on CAE Technology
Kim, Sung-Jong ; Lee, Sang-Kwon ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 107~116
The excitation force of a powertrain is one of major sources for the interior noise of a vehicle. This paper presents a novel approach to predict the interior noise caused by the vibration of the power rain by using the hybrid TPA (transfer path analysis) method. Although the traditional transfer path analysis (TPA) is useful for the identification of powertrain noise sources, it is difficult to modify the structure of a powertrain by using the experimental method for the reduction of vibration and noise. In order to solve this problem, the vibration of the power rain in a vehicle is numerically analyzed by using the finite element method (FEM). The vibration of the other parts in a vehicle is investigated by using the experimental method based on vibrato-acoustic transfer function (VATF) analysis. These two methods are combined for the prediction of interior noise caused by a power rain. Throughout this research, two papers are presented. This paper presents a simulation of the excitation force of the power rain exciting the vehicle body based on numerical simulation. The other paper presents a prediction of interior noise based on the hybrid TPA, which uses the VATF of the car body and the excitation force predicted in this paper.
Prediction of Interior Noise by Excitation Force of Powertrain Based on Hybrid Transfer Path Analysis
Kim, Sung-Jong ; Lee, Sang-Kwon ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 117~124
In early design stage, the simulation of interior noise is useful for the enhancement of the noise, vibration and harshness (NVH) performance in a vehicle. The traditional transfer path analysis (TPA) technology cannot simulate the interior noise since it uses the experimental method. In order to solve this problem, in this paper, the hybrid TPA is developed as the novel approach. The hybrid TPA uses the simulated excitation force as the input force, which excites the flexible body of a car at the mount point, while the traditional TPA uses the measured force. This simulated force is obtained by numerical analysis for the FE (finite element) model of a powertrain. The interior noise is predicted by multiplying the simulated force by the vibro-acoustic transfer function (VATF) of the vehicle. The VATF is the acoustic response in the compartment of a car to the input force at the mount point of the powertrain in the flexible car body. The trend of the predicted interior noise based on the hybrid TPA very well corresponds to the measured interior noise, although there is some difference due to not only the experimental error and the simulation error but also the effect of the air-borne path.
Thermal stress analysis for an aspheric glass lens mold
Lee, Young-Min ; Chang, Sung-Ho ; Heo, Young-Moo ; Shin, Kwang-Ho ; Yoon, Gil-Sang ; Jung, Tea-Sung ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 125~131
In the past, precision optical glass lenses were produced through multiple processes such as grinding and polishing, but mass production of aspheric lenses requiring high accuracy and having complex profile was rather difficult. In such a background, the high-precision optical GMP processes were developed with an eye to mass production of precision optical glass parts by molding press. Generally because the forming stage in a GMP process is operated at high temperature above
, thermal stresses and deformations are generated in the aspheric glass lens mold that is used in GMP process. Thermal stresses and deformations have negative influences on the quality of a glass lens and mold, especially the height of the deformed glass lens will be different from the height of designed glass lens. To prevent the problems of a glass lens mold and the glass lens, it is very important that the thermal stresses and deformations of a glass lens mold at high forming temperature are considered at the glass molds design step. In this study as a fundamental study to develop the molds used in an aspheric glass lens fabrication, a heat transfer and a thermal stress analysis were carried out for the case of one cavity glass lens mold used in progressive GMP process. Finally using analysis results, it was predicted the height of thermally deformed guide ring and calculated the height of the guide ring to be modified,
. This result was referred to design the glass lens molds for GMP process in production field.
Design and Evaluation of a Rotation Table using Air Bearings for Electron Beam Mastering
Khim, Gyung-Ho ; Song, Chang-Kyu ; Park, Chun-Hong ;
Journal of the Korean Society for Precision Engineering, volume 25, issue 12, 2008, Pages 132~138
Recently, mastering processes for high density optical disc such as Blu-ray disc rely on electron beams, which are operable in only vacuum. In the mastering process, one of the most important tasks is to design precision stages for providing precise positioning of the works with respect to the source in a high vacuum environment. In this paper, we have developed a precision rotation table usable in the electron beam mastering. The rotation table adopted air bearings for a high positioning repeatability and velocity stability. The air leakage from the air bearings has been minimized by employing the differential exhaust scheme using three steps of air drain. The design parameters such as diameters of exhaust lines, seal lengths, and pumping speeds were decided according to the optimization method using genetic algorithm. The performance on the vacuum level of the rotation table was evaluated experimentally and theoretically. The results indicate that a vacuum level of
Pa is achieved with operation of air bearings in a vacuum chamber, which is sufficient for the electron beam mastering.