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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Precision Engineering
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Journal DOI :
Korean Society of Precision Engineering
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Volume & Issues
Volume 28, Issue 12 - Dec 2011
Volume 28, Issue 11 - Nov 2011
Volume 28, Issue 10 - Oct 2011
Volume 28, Issue 9 - Sep 2011
Volume 28, Issue 8 - Aug 2011
Volume 28, Issue 7 - Jul 2011
Volume 28, Issue 6 - Jun 2011
Volume 28, Issue 5 - May 2011
Volume 28, Issue 4 - Apr 2011
Volume 28, Issue 3 - Mar 2011
Volume 28, Issue 2 - Feb 2011
Volume 28, Issue 1 - Jan 2011
Selecting the target year
A T-S Fuzzy Identification of Interior Permanent Magnet Synchronous
Wang, Fa-Guang ; Kim, Min-Chan ; Kim, Hyun-Woo ; Park, Seung-Kyu ; Yoon, Tae-Sung ; Kwak, Gun-Pyoung ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 391~397
Control of interior permanent magnet (IPMSM) is difficult because its nonlinearity and parameter uncertainty. In this paper, a fuzzy c-regression models clustering algorithm which is based on T-S fuzzy is used to model IPMSM with a series linear model and weight them by memberships. Lagrangian of constrained function is built for calculating clustering centers where training output data are considered. Based on these clustering centers, least square method is applied for T-S fuzzy linear model parameters. As a result, IPMSM can be modeled as T-S fuzzy model for T-S fuzzy control of them.
A Study on the Fundamental Characteristics Analysis of Giant Magnetostrictive Materials
Kim, Dong-Hyeon ; Lee, Choon-Man ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 398~403
Terfenol-D is one of several magnetostrictive materials with property of converting energy into mechanical motion, and vice versa. Magnetostriction is the property that causes certain ferromagnetic materials to change shape in a magnetic field. Terfenol-D is said to produce giant magnetostriction, strain greater than any other commercially available smart material. In this paper, fundamental characteristics analysis of giant magnetostrictive materials(Terfenol-D) has been investigated. The magnetic field analysis is carried out by using finite element method simulation ANSYS. The results show 223N in force and 9.5T in maximum magnetic flux density and 7.56
in maximum magnetic field intensity 1A current. Through the analysis, basic data of Terfenol-D for the application of mechanical system are obtained.
Estimation of Measurement Uncertainty for Vibration Tests in the Machine Tool Main Spindle
Lee, Jung-Hoon ; Yoon, Sang-Hwan ; Chau, Dinh Minh ; Park, Min-Won ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 404~409
Report on the notion of uncertainty is important. The reason is that the measured value includes a lot of uncertain factors. Reliable results can't be derived without the notion of uncertainty. The mathematical model to evaluate uncertainty considering the quality of vibration is important to evaluate uncertainty, and it must contain the every quantity which contributes significantly to uncertainty in the measured results. In this paper, the evaluation of uncertainty analysis about rotor vibration measurements of machine tools is presented to evaluate the most important factors of uncertainty.
A Study on the Determination of the Oil Gap in the Hydrostatic Spindle System for a Crank Shaft Grinding Machine
Park, Dong-Keun ; Choi, Chi-Hyuk ; Lee, In-Jae ; Lee, Choon-Man ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 410~415
A cylindrical type of self-controlled restrictor is designed for hydrostatic bearing of crank shaft for a grinding wheel spindle. The effect of operation parameters, clearance between spindle and housing on bearing stiffness are analyzed to determine the optimum conditions of operation parameters. The lowest values of the supply pressure and the loads by the theoretical and experimental results assuming oil film thickness and shape of pocket are compared.
A Fundamental Study on the Development of Variable Preload Device Using Rubber Force
Choi, Chi-Hyuk ; Kim, Dong-Hyeon ; Lee, Choon-Man ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 416~421
Recently there has been increase in need for high precision and high speed machining due to economic and environmental reasons. It is a very important issue that determines the optimal preload that is to be applied to bearings in order to satisfy the performance required in bearings according to its operation conditions. This study introduces a variable preload device that can automatically adjust the preload applied in a machine tool spindle using centrifugal force as opposed in existing rubber instrument. In this study, the deformation of the rubber device by the centrifugal force is analyzed and it is discussed that the proposed device can be worked properly through changes of the collar density.
The Static and Dynamic Analysis of a 45,000rpm Spindle for a Machine Tool and Evaluation of Its Stiffness
Kim, Dong-Hyeon ; Lee, Choon-Man ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 422~426
The spindle system is very important unit for the product accuracy in machine tools. A spindle system is designed by using the angular contact ceramic ball bearings, built-in motor, oil-air lubrication method and oil jacket cooling method. The static and dynamic analysis and stiffness evaluation of 45,000rpm spindle for machine tool has been investigated. Using a finite element method, we obtained some analyzed a static and dynamic characteristics of a spindle, such as natural frequency, harmonic analysis and we got the value of compliance through it. We evaluated stiffness by taking the inverse this value. A 45,000rpm spindle is successfully developed using the results.
Analysis of Curve Squeal Noise for Busan Metro Line 3
Hong, Do-Kwan ; Ahn, Chan-Woo ; Han, Geun-Jo ; Gang, Hyeon-Uk ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 427~435
This paper deals with the measurement and analysis of the squeal noise according to the curvature of rail. The squeal noise is generated by the friction between the railway with curve and the wheel. The squeal noise is a big problem in Busan Metro Line 3. If the developing panel type ANC(Active Noise Control) system which is attached to the floor can reduce 5 dB in below 500 Hz, the sound pressure level of the whole band pass can be reduced about 4-4.8 dB in squeal noise above the curvature of R400. Curve squeal noise is the intense high frequency tonal that can occur when a railway vehicle transverses a curve. The frequency range is from around 500 to almost 20,000 Hz, with noise levels up to about 15 dB in curve.
Implementation of Multiple Connectivity using CANopen in IEEE 1451.0-based Smart Sensor
Park, Jee-Hun ; Lee, Suk ; Song, Young-Hun ; Lee, Kyung-Chang ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 436~445
As automation systems become intelligent and autonomous for productibility, industrial networks (fieldbuses) and network-based devices are essential components of intelligent manufacturing systems. However, there are obstacles for the wide acceptance of the network-based devices such as smart sensor and network-based actuator. First, there exist numerous fieldbus protocols that a network-based device should be able to support. Second, the whole network-based device has to be replaced when only the sensor of the module fails. In order to overcome these obstacles, a smart sensor/actuator is implemented as two units; one responsible for network communication and the other for sensor/actuator operations using IEEE 1451.0 standard. This paper presents a structure of the 1451.0-based smart sensor with multiple connectivity function designed by CANopen.
Design of a Flexible Robot Foot with Toes and Heel Joints
Park, Jin-Hee ; Kim, Hyun-Sul ; Kwon, Sang-Joo ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 446~454
In terms of the anatomy and mechanics of the human foot, a flexible robot foot with toes and heel joints is designed for a bipedal walking robot. We suggest three design considerations in determining foot design parameters which are critical for walking stability. Those include the position of the frontal toe, the stiffness of toes and heels, and the position of the ankle joint. Compared with the conventional foot with flat sale, the proposed foot is advantageous for human-like walking due to the inherent structural flexibility and the reasonable parameter values. Simulation results are provided to determine the design parameters and also show that the proposed foot enables smaller energy consumption.
Study of a Gravity Compensator for the Lower Body
Choi, Hyeung-Sik ; Kim, Dong-Ho ; Jeon, Ji-Kwang ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 455~462
This paper is about the design of a new gravity compensator for the lower body exo-skeleton device. The exo-skeleton devices is for increasing the torque of the human body joint for the purpose of helping the disabled, workers in the industry, and military soldiers. So far, most of studied exo-skeleton devices are actuated by the motors, but motors are limited in energy such that a short durability is always a big problem. In this paper, a new gravity compensator is proposed to reduce the torque load applied to human body joints due to gravity. The gravity compensator is designed using a tortional bar spring, and its structure and characteristics are studied through the test and computer simulation. A design concept on the exo-skeleton device using the gravity compensator is presented. An analysis and computer simulation on the torque reduction of the proposed exo-skeleton device that applies and non-applies the gravity compensator are performed.
A Prediction of the Amount of Dimensional Deformation of Addendum and Dedendum after Shrink Fitting Process
Kim, Ji-San ; Hwang, Beam-Cheal ; Bae, Won-Byong ; Kim, Chul ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 463~473
The warm shrink fitting process is generally used to assemble automobile transmission parts (shaft/gear). But the fitting process can cause the dimensions of addendum and dedendum of the gear to change with respect to the fitting interference and the profile of the gear. As a result, there may be additional noise and vibration between gears. To address these problems, we analyzed the warm shrink fitting process according to process parameters; the fitting interference between the outer diameter of the shaft and the inner diameter of the gear, the inner diameter of the gear, addendum and dedendum of the gear, the heating temperature. In this study, a closed form equation for predicting the amount of deformation of addendum and dedendum in the R-direction was proposed. And the FEA method to analyze the cooling process was proposed for thermal-structural-thermal coupled field analysis of the warm shrink fitting process (heating-fitting-cooling process).
A Finite Element Analysis of Incisors with Different Material Combinations of a Post and a Core
Kang, Min-Kyu ; Tak, Seung-Min ; Lee, Seok-Soon ; Seo, Min-Seock ; Kim, Hyo-Jin ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 474~481
The purpose of this study was to investigate the effect of rigidity of post core systems on stress distribution by the finite element stress analysis method. Three-dimensional finite element models simulating an endodontically treated maxillary central incisor restored with a zirconia crown were prepared. Each model contained cortical bone, trabecular bone, periodontal ligament, 4mm apical root canal filling, and post-and-core. A 50N static occlusal load was applied to the palatal surface of the crown with a
angle to the long axis of the tooth. And three parallel type post (zirconia, glass fiber and stainless steel) and two core (Paracore and Tetric ceram) materials were evaluated, respectively. The differences in stress transfer characteristics of the models were analyzed. von Mises stresses were chosen for presentation of results and maximum displacement and hydrostatic pressure were also calculated. For the Result of the research, the model applied glass fiber to post material has lowest von Mises stress and it is suitable for material of post core systems.
Multi-level Shape Optimization of Lower Arm by using TOPSIS and Computational Orthogonal Array
Lee, Kwang-Ki ; Han, Seung-Ho ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 482~489
In practical design process, designer needs to find an optimal solution by using full factorial discrete combination, rather than by using optimization algorithm considering continuous design variables. So, ANOVA(Analysis of Variance) based on an orthogonal array, i.e. Taguchi method, has been widely used in most parts of industry area. However, the Taguchi method is limited for the shape optimization by using CAE, because the multi-level and multi-objective optimization can't be carried out simultaneously. In this study, a combined method was proposed taking into account of multi-level computational orthogonal array and TOPSIS(Technique for Order preference by Similarity to Ideal Solution), which is known as a classical method of multiple attribute decision making and enables to solve various decision making or selection problems in an aspect of multi-objective optimization. The proposed method was applied to a case study of the multi-level shape optimization of lower arm used to automobile parts, and the design space was explored via an efficient application of the related CAE tools. The multi-level shape optimization was performed sequentially by applying both of the neural network model generated from seven-level four-factor computational orthogonal array and the TOPSIS. The weight and maximum stress of the lower arm, as the objective functions for the multi-level shape optimization, showed an improvement of 0.07% and 17.89%, respectively. In addition, the number of CAE carried out for the shape optimization was only 55 times in comparison to full factorial method necessary to 2,401 times.
Development of Single Slide-Rail System for Reduction of Unbalanced Sliding Motion
Kim, Min-Hoon ; Park, Ki-Hong ; Jeong, Won-Chul ; Ye, Sung-Bong ; Park, Sang-Hu ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 490~495
A slide-rail system is widely used in home appliances, furniture, mechanical rigs, and so many other applications; due to its high strength and performance for easy moving heavy objectives. In general, a pair of side slide-rails is set on both sides of a drawer to support and move it. So an unbalanced sliding motion can occur during opening and closing a drawer with pull and push force. To settle this problem, single central slide-rail having three collapsible rail-bodies was firstly proposed in this work. 'H'-beam shaped rail-body was newly designed to have enough bending and twisting strength. The experimental test showed that the proposed rail could be applied to large-size home appliances for easy moving drawer with heavy weight.
Improvement of the Stamping Process for Sheet Metal Prototypes of an Auto-body with Finite Element Analysis
Kim, Se-Ho ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 496~504
This paper introduces a CAE-based design procedure in the press forming process for the fabrication of sheet metal parts used in proto-cars. The finite element analysis reveals formability problems during the forming process of a floor member and a front cross member that constitute a rear floor assembly. The study proposes the modification of the initial blank shape or intermediate trimming of the product to prevent failure during forming. It is confirmed by the tryout process as well as the finite element analysis that sound prototype can be obtained with the modified design. The finite element analysis result also provides fairly good prediction of springback amounts used for the post-compensation of the product.
Improvement of the Thermal Behavior of the Secondary Part of Synchronous Linear Motors with High Speed and Thrust
Eun, In-Ung ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 505~512
Linear permanent magnet synchronous motors utilize high-energy product permanent magnet to produce high thrust, velocity and acceleration. Such motors are finding applications requiring high positioning accuracy and speed response, for example, machine tools, in the absence of mechanical gears and ball screw systems. A disadvantage of the linear motors is high power loss in comparison with rotary motors. For the application of the linear motors to machine tools, it is required to use water coolers and to improve the thermal behavior through insulation and structure optimization or control strategies. This paper presents the function of the secondary part of the linear synchronous motor as to the thermal behavior and the improving method. The result shows cooling pipe combined with an insulation layer is a suitable design for improving of the thermal behavior.
Design and Implementation of Nanoimprint Lithography System for Flexible Substrates
Lim, Hyung-Jun ; Lee, Jae-Jong ; Choi, Kee-Bong ; Kim, Gee-Hong ; Ryu, Ji-Hyeong ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 513~520
The NIL processes have been studied to implement low cost, high throughput and high resolution application. A RNIL(roller NIL) is an alternative approach to flat nanoimprint lithography. RNIL process is necessary to transfer patterns on flexible substrates. Compared with flat NIL, RNIL has the advantages of better uniformity, less pressing force, and the ability to repeat the patterning process continuously on a large substrate. This paper studies the design, construction and verification of a thermal RNIL system. The proposed RNIL system can easily adopt the flat shaped hot plate which is one of the most important technologies for NIL. The NIL system can be used to transfer patterns from a flexible stamp to a flexible substrate, from a flexible stamp to a Si substrate, and from a roller stamp to a flexible substrate, etc. Patterning on flexible substrates is one of the key technologies to produce bendable displays, solar cells and other applications.
Effect of Low Intensity Sound Wave on UC-MSC(Umbilical Cord Mesenchymal Stem Cell Growth
Kim, Sung-Min ; Kang, Seung-Ho ; Jeong, Jae-Hoon ; Park, Jung-Keug ; Kim, Soo-Chan ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 521~525
It is known that the low-intensity sound stimulation really affect to grow the cell. The cellular growth mechanism, however, does not been clearly identified even the effect on the low-intensity sound stimulation. The purpose of this study is to investigate the effect of low-intensity sound stimulation on the alveolar UC-MSC proliferation. Before the low-intensity sound stimulation is applied, the UC-MSC are cultured for 24 hours to facilitate their attachments. The cells are divided into two groups. And each was exposed to a medium with or without the low-intensity ultrasound stimulation at 71dB intensity level. The UC-MSC are again divided into three treatment groups of group 1, 2, and 3 and exposed to a frequency at 50Hz, 100Hz, and 1000Hz, respectively. In the results, it is investigated that the growth rates of UC-MSC for the stimulated groups were higher than those of control groups. In 1000Hz frequency, the number of UC-MSC cell is significantly higher than control groups (p>0.05). We would put the hypothesis that the cell growth could be enhanced by an appropriate low-intensity sound stimulation.
Development of the Pulsatile Pump System for a Perfusion Bioreactor
Kim, Hak-Jun ; Kim, Sun-Hong ; Chung, Ho-Yun ; Yun, Won-Soo ;
Journal of the Korean Society for Precision Engineering, volume 28, issue 4, 2011, Pages 526~533
This research is about the pulsatile pump system utilized in the perfusion bioreactor for the in vitro human tissue culture. A pulsatile pump system which can be applied to the culture of the vascular tissues including blood vessel is developed by using the idea of human heart's blood pumping into organs as followings: culture chamber, a pressurizing device which generates laminar pulsatile flow by controlling the x-sectional area of the culture media delivering tubing, a compliance chamber which supplies the pressuring device with a constant pressure, and a peristaltic pump which circulates the culture media in a circuit ranging from the culture chamber to the compliance chamber. The developed pulsatile pump system shows that a physiology of the human heart's blood pumping including pulsatile pressure waveform of systolic-diastolic pressure is well represented. Not only time domain but also frequency domain characteristics of pulsatile pump system which are necessary for the vascular tissue culture such as pulsatile pressure waveform's shape, the frequency, and the magnitude can be easily generated and manipulated by using the proposed system.