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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 24, Issue 12 - Dec 2007
Volume 24, Issue 11 - Nov 2007
Volume 24, Issue 10 - Oct 2007
Volume 24, Issue 9 - Sep 2007
Volume 24, Issue 8 - Aug 2007
Volume 24, Issue 7 - Jul 2007
Volume 24, Issue 6 - Jun 2007
Volume 24, Issue 5 - May 2007
Volume 24, Issue 4 - Apr 2007
Volume 24, Issue 3 - Mar 2007
Volume 24, Issue 2 - Feb 2007
Volume 24, Issue 1 - Jan 2007
Selecting the target year
Biomechanical Evaluation of Posterior Cruciate Ligament Reconstruction Using Finite Element Model of Knee Joint
Kim, Yoon-Hyuk ; Park, Won-Man ; Kim, Sang-Hoon ; Kim, Kyung-Soo ; Lee, Soon-Geul ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 7~12
Morphological Study of the Mandibular Second Molar Using a Micro-CT
Chun, Kyoung-Jin ; Yoo, Oui-Sik ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 13~19
Dynamic Analysis of Canine Tibialis Cranialis-Ankle Joint Musculoskeletal Structure and Experimental Validation
Min, Sung-Ki ; Choi, Hwan ; Lee, Soon-Hyuck ; Lee, Sung-Ho ; Hong, Jung-Hwa ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 20~28
Changes of Muscle Length and Roll-Over Characteristics During High-heel Walking
Son, Jong-Sang ; Choi, Hue-Seok ; Hwang, Sung-Jae ; Kim, Young-Ho ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 29~35
Analysis of an Active Catheter Using Thermal Equivalent Modeling of IPMC
Park, Heung-Seok ; Lee, Jang-Yeol ; Jho, Jae-Young ; Rhee, Kye-Han ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 36~41
Machining Characteristics of Micro-EDMed Holes According to Dielectric Fluid, Capacitance and Ultrasonic Vibrations
Seo, Dong-Woo ; Yi, Sang-Min ; Chu, Chong-Nam ; Park, Min-Soo ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 42~49
When micro holes are machined by EDM, machining characteristics of machined holes are changed according to the machining conditions. Typical machining conditions are the kind of dielectric fluids, capacitance and ultrasonic vibrations. They influence electrode wear, machining time, radial clearance and taper angle. In this paper, machined holes whose depths are 300, 500,
are observed for each machining conditions. Using deionized water as a dielectric fluid makes electrode wear small, machining time short, radial clearance large and taper angle small. High capacitance makes electrode wear high. Ultrasonic vibrations make electrode wear large, machining time short, radial clearance small and taper angle small. From the results of experiments, the optimal machining conditions were obtained to machine highly qualified micro holes.
Femtosecond Pulsed Laser Ablation of OLED Shadow Mask Invar Alloy
Chung, Il-Young ; Kang, Kyung-Ho ; Kim, Jae-Do ; Sohn, Ik-Bu ; Noh, Young-Chul ; Lee, Jong-Min ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 50~56
Femtosecond laser ablation of the Invar alloy and hole drilling for a shadow mask are studied. We used a regenerative amplified Ti-sapphire laser with a 1kHz repetition rate, 184fs pulse duration and 785nm wavelength. Femtosecond laser pulse was irradiated on the Invar alloy with air blowing at the condition of various laser peak power. An ablation characteristic of the Invar alloy was appeared non-linear at
of energy fluence. For the application to a shadow mask, the hole drilling of the Invar alloy with the cross section of a trapezoidal shape was investigated. The ablated micro-holes were characterized using an atomic force microscopy(AFM). The optimal condition of hole pattern f3r a shadow mask was
z-axis feed rate, 0.2mm/s circular velocity,
laser peak power. With the optimal processing condition, the fine circular hole shape without burr and thermal damage was achieved. Using the femtoseocond laser system, it demonstrates excellent tool for the Invar alloy micro-hole drilling without heat effects and poor edge.
PID Learning Controller for Multivariable System with Dynamic Friction
Chung, Byeong-Mook ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 57~64
There have been many researches for optimal controllers in multivariable systems, and they generally use accurate linear models of the plant dynamics. Real systems, however, contain nonlinearities and high-order dynamics that may be difficult to model using conventional techniques. Therefore, it is necessary a PID gain tuning method without explicit modeling for the multivariable plant dynamics. The PID tuning method utilizes the sign of Jacobian and gradient descent techniques to iteratively reduce the error-related objective function. This paper, especially, focuses on the role of I-controller when there is a steady state error. However, it is not easy to tune I-gain unlike P- and D-gain because I-controller is mainly operated in the steady state. Simulations for an overhead crane system with dynamic friction show that the proposed PID-LC algorithm improves controller performance, even in the steady state error.
Gain Scheduled State Feedback and Disturbance Feedforward Control for Systems with Bounded Control Input - Application
Kang, Min-Sig ; Yoon, Woo-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 65~73
In this paper, the gain scheduled state feedback and disturbance feedforward control design proposed in the previous paper has been applied to a simple matching system and a turret stabilization system. In such systems, it is needed to attenuate disturbance response effectively as long as control input satisfies the given constraint on its magnitude. The scheduled control gains are derived in the framework of linear matrix inequality(LMI) optimization by means of the MatLab toolbox. Its effectiveness is verified along with the simulation results compared with the conventional optimum constant gain control and the scheduled state feedback control cases.
A Study on the Evaluation Technique of Quantified Damage for Powertrain System on Traveled Courses
Lee, Sang-Ho ; Lee, Jeong-Hwan ; Kang, Do-Kyung ; Goo, Sang-Hwa ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 74~81
This paper focuses on improvement of the reliability for endurance test to serve military automobiles. The driving loads have been measured by use of the wireless telemetry system for the drive shaft of the 4-wheel drive car. In order to analyze the transmission input torque and engine revolution of loads of the test courses and unpaved road have been made use of the revolution counting and cumulative damage by miner's rule. This paper presents the evaluated result for quantified damage about the test courses and roads.
Position Control of the Pneumatic Excavator System Using Adaptive Sliding Mode Controller
Lim, Tae-Hyeong ; Cheon, Se-Young ; Yang, Soon-Yong ; Choi, Jeong-Ju ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 82~87
Excavator has been used in wide field since the attachment in the end effect can be changeable according to the purpose of working. However, efficiency of work using excavator mainly depends on an operator's ability. For the purpose of improving the efficiency of work and reducing the fatigue of operator, the automatic excavator system has been researched. In this paper, the tracking control system of each links of excavator is designed before developing the automatic excavator system. In order to apply the tracking control system, the pneumatic excavator system is developed and the tracking control system is applied. For designing the tracking control system, the adaptive sliding mode control algorithm is proposed. The performance of the proposed control system is evaluated through experiments using the pneumatic excavator system.
Analysis of a Rotation Stage with Cartwheel-type Flexure Hinges Driven by a Stack-type Piezoelectric Element
Choi, Kee-Bong ; Lee, Jae-Jong ; Kim, Min-Young ; Ko, Kuk-Won ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 88~94
A flexure hinge-based compliant stage driven by stack-type piezoelectric elements has high precision motion but small operational range due to the characteristics of the piezoelectric element. Since the common flexure hinges can be broken by excessive deflection when the displacement is amplified by a high amplification ratio, a flexure hinge mechanism for large deflection is required. A cartwheel-type flexure hinge has an advantage of larger deflection compared with the common flexure hinges. This study presents a rotation stage with cartwheel-type flexure hinges driven by a stack-type piezoelectric element. The characteristics and the performance of the rotation stage are described by the terms of principal resonance frequency, amplification ratio of rotational displacement, maximum rotational displacement and block moment, in which the terms are analyzed by geometric parameters of the rotation stage. The analyzed results will be used as the guideline of the design of the rotation stage.
Liquid Cooling System Using Planar ECF Pump for Electronic Devices
Seo, Woo-Suk ; Ham, Young-Bog ; Park, Jung-Ho ; Yun, So-Nam ; Yang, Soon-Young ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 95~103
This paper presents a liquid cooling concept for heat rejection of high power electronic devices existing in notebook computers etc. The design, fabrication, and performance of the planar ECF pump and farced-liquid cooling system are summarized. The electro-conjugate fluid (ECF) is a kind of dielectric and functional fluids, which generates jet flows (ECF-jets) by applying static electric field through a pair of rod-like electrodes. The ECF-jet directly acts on the working fluid, so the proposed planar ECF pump needs no moving part, produces no vibration and noise. The planar ECF pump, consists of a pump housing and electrode substrate, achieves maximum flow rate and output pressure of
and 7.2 kPa, respectively, at an applied voltage of 2.0 kV. The farced-liquid cooling system, constructed with the planar ECF pump, liquid-cooled heat sink and thermal test chip, removes input power up to 80 W keeping the chip surface temperature below
. The experimental results demonstrate that the feasibility of forced-liquid cooling system using ECF is confirmed as an advanced cooling solution on the next-generation high power electronic devices.
A Study on Evaluation of Defects of Pressure Vessel by Using ESPI and FEM
Kang, Young-June ; Lee, Jung-Sik ; Baik, Sung-Hoon ; Park, Seung-Kyu ; Lee, Dong-Hwan ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 104~110
Internal defects are mainly caused by a corrosive action and degradation in the pipe used in a nuclear power plant or factory. The ESPI method have the many advantages when compared with conventional method. The advantage are the area measurement ability at one time and non-contact measurement ability in the real-time. In this paper, we studied on the measurement of a internal defect by using out of plane ESPI technique. Here, we compared the experimental results using out of plane ESPI with the FEM results.
The Variations of Tensile and Fatigue Properties in the Hydroforming Process
Oh, Chung-Seog ; Kwon, Soon-Gue ; Choi, Byung-Ik ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 111~118
Hydroforming is a cost-effective way of shaping malleable metals such as steel into lightweight, structurally stiff and strong pieces. With the increased use of the hydroformed components in automotive and aerospace industries, it is important to know the variations of the mechanical properties in the hydroforming process far the safe and durable design purposes. The principal goal of this paper is to suggest a procedure to evaluate the variations of tensile and fatigue properties before and after a hydroforming process. A miniature specimen, which is 0.2 mm thick and 2.3 mm wide, is devised and tested to measure local mechanical properties. The effects of specimen size, defects, surface roughness, and hydroforming on the tensile and fatigue behaviors are discussed.
Improvement of Mechanical Properties of UV-curable Resin for High-aspect Ratio Microstructures Fabricated in Microstereolithography
Lee, Su-Do ; Choi, Jae-Won ; Park, In-Beak ; Ha, Chang-Sik ; Lee, Seok-Hee ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 119~127
Recently, microstructures fabricated using microstereolithography technology have been used in the biological, medical and mechanical fields. Microstereolithography can fabricate real 3D microstructures with fine features, although there is presently a limited number of materials available for use in the process. Deformation of the fine features on a fabricated microstructure remains a critical issue for successful part fabrication, and part deformation can occur during rinsing or during fabrication as a result of fluid flow forces that occur during movement of mechanical parts of the system. Deformation can result in failure to fabricate a particular feature by breaking the feature completely, spatial deflection of the feature, or attaching the feature to neighboring microstructures. To improve mechanical strength of fabricated microstructures, a clay nanocomposite can be used. In particular, a high-aspect ratio microstructure can be fabricated without distortion using photocurable liquid resin containing a clay nanocomposite. In this paper, a clay nanocomposite was blended with a photocurable liquid resin to solve the deformation problem that occurs during fabrication and rinsing. An optimal mixture ratio of a clay nanocomposite was found through tensile testing and the minimal allowable distance between microstructures was found through fabrication experimentation. Finally, using these results, high-aspect ratio microstructures were fabricated using a clay nanocomposite resin without distortion.
Fabrication of Micro-channels for Wave-Micropump Using Stereolithography and UV Photolithography
Loh, Byoung-Gook ; Kim, Woo-Sik ; Shim, Kwang-Bo ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 128~135
Micro-channels for a wave micropump have been fabricated using the Stereolithography and UV Photolithography. The micro-channel with a channel height of
was fabricated with stereolithography. UV photolithography was used for producing micro-channels with a channel length less than
. The fabrication process data including spinning rpm, pre-bake and post-bake time, and develop time for single layer and multiple layer 3D micro-structures using SU-8 photo resist are experimentally found. A film mask printed with a 40,000 dpi laser printer was used for UV lithography and micro-structures in the order of tens of micrometers in dimension were successfully fabricated.
Contact Print Lithography for Precise Transplantation of Three-dimensional Microstructures into a Microsystem
Park, Sang-Hu ; Jeong, Jun-Ho ; Choi, Dae-Geun ; Kim, Ki-Don ; Altun, Ali Ozhan ; Lee, Eung-Sug ; Yang, Dong-Yol ; Kong, Hong-Jin ; Lee, Kwang-Sup ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 136~142
Precise fabrication of three-dimensional (3D) self-standing microstructures on thin glass plates via two-photon induced polymerization (TPP) has been an important issue for innovative 3D nanodevices and microdevices. However, there are still issues remaining to be solved, such as building 3D microstructures on opaque materials via TPP and being able to implant them as functional parts onto practical systems. To settle these issues simply and effectively, we propose a contact print lithography (CPL) method using an ultraviolet (UV)-curable polymer layer. We report some of the possibilities and potential of CPL by presenting our results for transplanting 3D microstructures onto large-area substrates and also our examination of some of the effects of the process parameters on successful transplantation.
A Study on the Improvement of Adhesive Strength of Between Metal and Polyethylene Materials
Lee, Ji-Hoon ; Kim, Hyun-Ju ; Jung, Dong-Ho ; Rhee, Kyong-Yop ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 12, 2007, Pages 143~148
Polyethylene is a typical hydrophobic material and it is difficult to bond the polyethylene material with metal material. Thus, it is important to modify the surface of polyethylene material to improve the bonding strength between the polyethylene and the metal materials. In this study, the surface modification of polyethylene material was investigated to improve the interfacial strength between the polyethylene and the steel materials. Polyethylene material was surface-modified in a plasma cleaner using an oxygen gas. Two cases of composites (surface-modified pelyethylene/steel composite and regular (as-received) pelyethylene/steel composite) were fabricated using a secondary bonding method. Shear and bending tests have been performed using the two cases of composites. The results showed that the contact angle did not change much as the modification time increased. However, the contact angle decreased from
with the modification. The results also showed that the shear strength and the bending strength were improved about 3030 % and 7 %, respectively when the polyethylene was plasma-modified using an oxygen gas.