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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 22, Issue 12 - Dec 2005
Volume 22, Issue 11 - Nov 2005
Volume 22, Issue 10 - Oct 2005
Volume 22, Issue 9 - Sep 2005
Volume 22, Issue 8 - Aug 2005
Volume 22, Issue 7 - Jul 2005
Volume 22, Issue 6 - Jun 2005
Volume 22, Issue 5 - May 2005
Volume 22, Issue 4 - Apr 2005
Volume 22, Issue 3 - Mar 2005
Volume 22, Issue 2 - Feb 2005
Volume 22, Issue 1 - Jan 2005
Selecting the target year
Room-temperature and low-pressure nanoimprint lithography technology
Jeong Jun-ho ; Lee Eung-sug ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 7~15
Assembly and Patterning of Carbon Nanotube
Han Chang Soo ; Lee Eung-Sug ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 16~22
Injection Molding Technology for Micro/Nano pattern
Yoo Yeong-Eun ; Seo Young-Ho ; Je Tae Jin ; Choi Doo Sun ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 23~29
Process Design of Cold Forging for Drum Clutch with Inner Tooth Component
Park Sang Soo ; Kim Byung Min ; Lee Jung Min ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 30~37
A drum clutch which is a main part for the automatic transmission of auto-mobiles has been manufactured by glob threading and machining. The tooth shape of the drum clutch manufactured by machining has lower dimensional accuracy than that by pressing and its machining needs the enormous cost at plant investment. Thus, this study was designed to develop cold forging process and to improve the productivity and dimensional accuracy. In this work, variables affecting dimensional accuracy were first determined, then cold forming process design according to each variables was performed by FE simulation. Optimal process was suggested on the basis of analytical results.
A Study on the Reduction of Dishing and Erosion Defects in Tungsten CMP
Park Boumyoung ; Kim Hoyoun ; Kim Gooyoun ; Kim Hyoungjae ; Jeong Haedo ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 38~45
Chemical mechanical polishing(CMP) has been widely accepted for the planarization of multi-layer structures in semiconductor fabrication. But a variety of defects such as abrasive contamination, scratch, dishing, erosion and corrosion are occurred during CMP. Especially, dishing and erosion defects increase the metal resistance because they decrease the interconnect section area, and ultimately reduce the lift time of the semiconductor. Due to this reason dishing and erosion must be prohibited. The pattern density and size in chip have a significant influence on dishing and erosion occurred by over-polishing. The fixed abrasive pad(FAP) was applied and tested to reduce dishing and erosion in this paper. The abrasive concentration decrease of FAP results in advanced pattern selectivity which can lead the uniform removal in chip and declining over-polishing. Consequently, reduced dishing and erosion was observed in CMP of tungsten pattern wafer with proposed FAP and chemicals.
A Study on the Zeta-potential of CMP processed Sapphire Wafers
Hwang Sung Won ; Shin Gwisu ; Kim Keunjoo ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 46~52
The sapphire wafer was polished by the implementation of the surface machining technology based on nano-tribology, The removal process has been performed by grinding, lapping and chemical-mechanical polishing. For the chemical mechanical polishing process, the chemical reaction between the slurry and sapphire wafer was investigated in terms of the change of Zeta-potential between two materials. The Zeta-potential was -4.98 mV without the slurry in deionized water and was -37.05 mV for the slurry solution. By including the slurry into the deionized water the Zeta-potential -29.73 mV, indicating that the surface atoms of sapphire become more repulsive to be easy to separate. The average roughness of the polished surface of sapphire wafer was ranged to 1∼4
Analysis of Isolation System in Distinct Multi-mechanism HIF Device
Choe Eui Jung ; Kim Hyo-Jun ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 53~59
In this study, the isolation system for multi-mechanism HIF (high impulsive force) device has been investigated. For this purpose, parameter optimization process has been performed based on the simplified isolation system model under constraints of moving displacement and transmitted force. The design parameters for multi-mechanism HIF device have been derived with respect to HIF system I and HIF system II, respectively. In order to implement the dynamic absorbing system, the dual stage hydro-pneumatic damper and magnetorheological damper with semi-active control scheme are considered. Finally, the performance of the designed prototype isolation system has been evaluated by experimental works under actual operating conditions.
A Measurement Apparatus of Lateral Restoring Force Exerted on Electrostatically Suspended Object
Jeon Jong Up ; Park Ki-Tae ; Park Kyu-Yeol ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 60~69
In electrostatic suspension system of thin plates like a silicon wafer or an aluminum disk for hard disk applications, the lateral restoring force exerted on a suspended object plays an important role since the lateral motion of the suspended object, owing to the inherently stable restoring forces, can be passively stabilized without any active control of it. This paper reports about the measurement apparatus of the lateral restoring force originating from a relative translation of the suspended object with respect to the electrodes-for-suspension. An approximate calculation of the lateral force in disk-shaped objects, the structure of the measurement apparatus, a measurement method, stabilization condition and the guideline in designing the measurement apparatus are described. Experimental results obtained by using a 3.5-inch aluminum disk as a suspended object are presented as well in order to assess the magnitude of lateral force and stiffness, and also verify the usefulness of the measurement apparatus.
Rotor flux Observer Using Robust Support Vector Regression for Field Oriented Induction Mmotor Drives
Han Dong Chang ; Back Woon Jae ; Kim Sung Rag ; Kim Han Kil ; Lee Suk Gyu ; Park Jung IL ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 70~78
In this paper, a novel rotor flux estimation method of an induction motor using support vector regression(SVR) is presented. Two well-known different flux models with respect to voltage and current are necessary to estimate the rotor flux of an induction motor. Training of SVR which the theory of the SVR algorithm leads to a quadratic programming(QP) problem. The proposed SVR rotor flux estimator guarantees the improvement of performance in the transient and steady state in spite of parameter variation circumstance. The validity and the usefulness of proposed algorithm are throughly verified through numerical simulation.
Evaluation of Effective Orthotropic Creep Parameters for Perforated Sheets
Chung Ilsup ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 79~88
Evaluating the effective properties of materials containing various types of in-homogeneities is an important issue in the analysis of structures composed of those materials. A simple and effective method for the purpose is to impose the periodic displacement boundary conditions on the finite element model of a unit cell. Their theoretical background is explained based on the purely kinematical relations in the regularly spaced in-homogeneity problems, and the strategies to implement them into the analysis and to evaluate the homogenized material constants are introduced. The creep behavior of a thin sheet with square arrayed rectangular voids is characterized, where the orthotropy is induced by the presence of the voids. The homogenization method is validated through the comparison of the analysis of detailed model with that of the simplified one with the effective parameters.
A Study of auto-body panel correction of forming analysis that use One-step Forming method
Jung Dong Won ; Hwang Jae Sin ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 89~97
Thin plate correction of forming process that it is nowadays smile change of simple contact surface as it becomes possible that forecast dictionary numerically exactly to analyze comparative big comp displacement real industry spot problems between complicated and abnormal curved line shapes and thin plate and die more reliable and need many efforts yet economical analysis method is required and develops this efficient algorithm. This research analyzes correction of forming and examined possibility and validity of spot application using One-Step Finite Element Method. Its application is being increased especially in the automotive industrial area for the cost reduction, weight saving, and improvement of strength.
Analysis of Chattering Problem of a Glass Transfer Robot Hand
Kim Joo-Yong ; Kang Chul-Goo ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 98~104
A glass transfer robot is used for handling LCDs in the production line of flat panel displays under clean environments. During glass transfer operations of the robot, chattering phenomenon occurs at the robot hand. This deteriorates the accuracy and repeatability of the end-effector of the robot. In this paper, we present the kinematic solution of the robot and then analyze the cause of this chattering phenomenon in view of the mechanism and servo control and propose a practical solution that can reduce the chattering significantly at the robot hand of the glass transfer robot.
Shape Design of Guillotined Shear Cutters for Steel Pipes
Cho Haeyong ; Lee Sangmin ; Lee Sungkil ; Kim Yongyun ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 105~112
The guillotined cutting process for the pipe was studied in this paper. Until now guillotining mechanism can not be practically applied in the industries because of the deformation of sheared section around cutting area, the coarse sheared surface, and the burs. To find optimum shapes of blade, several types of blade were experimentally studied. The cutting force normal to the axial direction of the pipe was compared with the theoretical result based on the cutting energy. The experimental maximum cutting forces were very good agreement with the theoretical results. It also discussed that the design parameters of guillotining system such as the blade shape and the clearance between the blade and the die made effects to the deformation of the cutting cross section area. The results show that the guillotining method can be applicable to the pipe cutting system by optimizing the blade shape and the clearance between the blade and the die of the guillotined cutting system with respect to the sheared pipe material.
Effect of Domain Switching on Cracking in Ferroelectric Ceramic Actuators
Jeong Kyoung Moon ; Kim Jae Yun ; Beom Hyeon Gyu ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 113~119
A crack emanating from an internal electrode or a conducting damage path in ferroelectric ceramic actuators is analyzed. The boundary of the domain switching zone near the edge of the internal electrode in a ceramic multilayer actuator is determined based on the nonlinear electric theory. The stress intensity factor induced by a ferroelectric domain switching under small scale conditions is numerically obtained for flaws of various sizes near the electrode edge. It is found that stress intensity factor near the crack tip depends on the material property of the electrical nonlinearity.
Effect of Transverse Electric Fields on Fracture Behavior of Ferroelectric Ceramics
Lee Jong Sik ; Beom Hyeon Gyu ; Jeong Kyoung Moon ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 120~125
Effect of transverse electric fields on fracture behavior in ferroelectric ceramics under purely electrical loading is investigated. It is shown that the shape and size of the domain switching zone depend strongly on the ratio of the transverse electric field to the coercive electric field as well as the direction of the applied electric field. Under small-scale conditions, the crack-tip mode I and II stress intensity factors induced by ferroelectric domain switching are numerically obtained. The crack kinking in ferroelectric ceramics is also discussed.
A Development of the Design System of the Progressive Stamping Dies by using Boundary Representation and Its Application
Kim Yong Yun ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 126~132
In this paper, an auto-design system is introduced for a stamping tool based on commercial computer aided design system with its drafting language. The auto-design system consists of tool oriented product design subsystem which modifies and configures the product drawing, tool concept design subsystem which make a design of the punches and their punching progression and parts design subsystem that makes automatic dimension. The system is applied to the mechanical design of the stamping tool. The main logic of the system is based on half-edge theory, a kernel for the 3 dimensional CAD system, which is applied to 2 dimensional drafting auto-design system. The auto-design system enables to conspicuously reducing the designing time of the tool. In addition, there is little drafting error that had been about 3% without auto design program. It is effective to reduce the development time for new products because of rapid designing time of the tools, standardization of the stamping tool and the drafting rule for the auto-design system. The auto-design system yields high efficiency of the tool manufacturing system.
A Coarse Mesh Model for Numerical Analysis of Lead Frame Deformation Due to Blanking Residual Stress
Kim Yong Yun ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 133~138
The deformation of sheet metal due to the residual stress during blanking or piercing process, is numerically simulated by means of a commercial finite element code. Two dimensional plain strain problem is solved and then its result is applied to the deformation analysis of the lead frame. The plain strain element is applied to the 2D problem to observe the Von Mises equivalent stress concentration at the both shearing edges. As the punch penetrates into the sheet material, the stress concentration generated on both edges is getting increased to be the shearing surface. The limits of the punching depth applied to the simulation is 16% and 24% of the sheet thickness for the plain strain element and the hexahedral element, respectively. The hexahedral element and the limit of punching depth were applied to the deformation analysis of the lead frame for the blanking process. The FEM results for the lead deformation were very good agreement with the experimental ones. This paper shows that the coarse mesh has enabled to analyze the lead deformation generated due to the blanking mechanism. This simple approach to save the calculation time will be very effective to the design of the blanking tools in industries.
Adhesion between the Nylon Cylinder and Steel Shaft by Expansion Fit and Induction Heating
Choi Sin-Jin ; Kang Suk-Choon ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 139~147
The lubricant impregnated MC nylon has good frictional properties, but its mechanical strength is inferior to steel for the mechanical elements. For the tribological application Nylon as gears, sliding bearings, cam and etc, the steel shafts are fitted in pre-heated nylon cylinder by a process of interference expansion fit and bonded by induction heating method. The joint shear strength of the two materials was measured by a universal test machine. From the study, the adhesive shear strength between these two materials was affected by the factors of the interference between nylon and steel, the size of nylon cylinder, knurl of steel shaft and inducting heating conditions. The most effective jointing conditions were analyzed and decided for the practical application in the industry.
The Effect of Wind Load on the Stability of a Container Crane
Lee Seong Wook ; Shim Jae Joon ; Han Dong Seop ; Park Jong Seo ; Han Geun Jo ; Lee Kwon Soon ; Kim Tae Hyung ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 148~155
This study was carried out to analyze the effect of direction of wind load and machinery house location on the stability of container crane loading/unloading a container on a vessel. The overturning moment of container crane under wind load at 50m/s velocity was estimated by analyzing reaction forces at each supporting point. And variations of reaction forces at each supporting point of a container crane were analyzed according to direction of wind load and machinery house location. The critical location of machinery house was also investigated to install a tie-down which has an anti-overturning function of container crane at the land side supporting point.
A Study on the Location of Supporting Members in Monoleaflet Polymer Valve to Minimize Stress and Deformation
Lee Seong Wook ; Shim Jae Joon ; Han Dong Seop ; Han Geun Jo ; Kim Tae Hyung ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 156~163
A monoleaflet polymer artificial heart valve showed the remarkable improvement in pressure drop compared with other types of artificial valve. So, in this study we designed a monoleaflet polymer artificial valve with two supporting members to minimize the deformation and bending stress of the valve with respect to the variation of the gap between two supporting members using nonlinear contact analysis. The marginal valve thickness was also predicted in accordance with the relationship between the thickness and horizontal displacement in order to prevent the dislocation of the valve tip from the frame wall.
Penetration Characteristics of CFRP Laminated shells according to Stacking Sequence and Curvature
Cho Young Jea ; Kim Young Nam ; Yang In Young ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 164~171
This study aims to examine an effect of stacking sequence and curvature on the penetration characteristic of a composite laminated shell. For the purpose, we manufactured specimens with different stacking sequences and curvatures, and conducted a penetration test using an air-gun. To examine an influence according to stacking sequence, as flat plate and curvature specimen had more plies, their critical penetration energy was higher, Critical penetration energies of specimen A and C with less interfaces somewhat higher than those of B and D with more interfaces. The reason that with less interfaces, critical penetration energy was higher is pre-impact bending stiffness of composite laminated shell with less interfaces was lower than that of laminated shell with more interfaces, but bending stiffness after impact was higher. And it is because interface, the weakest part of the composite laminated shell, was influenced by transverse impact. As curvature increases, critical penetration energy increases linearly. It is because as curvature increases, resistance to in-plane deformation as well as bending deformation increases, which need higher critical penetration energy. Patterns of cracks caused by penetration of composite laminated shells include interlaminar crack, intralaminar crack, and laminar fracture. A 0
ply laminar had a matrix crack, a 90
ply laminar had intralaminar crack and laminar fracture, and interface between 0
laminar had a interlaminar crack. We examined crack length and delamination area through a penetration test. For the specimen A and C with 2 interface, the longest circumferential direction crack length and largest delamination area were observed on the first interface from the impact point. For the specimen B and D with 4 interface, the longest crack length and largest delamination area were observed on the third interface from the impact point.
Structural Characteristic Analysis of a High-Precision Centerless Grinding Machine with Concrete-Filled Bed
Kim Seok Il ; Cho Jae Wan ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 172~179
A high-precision centerless grinding machine has been recognized as a core equipment performing the finish outer-diameter grinding process of ferrules which are widely used as fiber optic connectors. In this study, in order to realize the high-precision centerless grinding machine, the structural characteristic analysis and evaluation are carried out on the virtual prototype consisted of the steel bed, hydrostatic GW and RW spindle systems, hydrostatic RW feed mechanism, RW swivel mechanism, and on-machine GW and RW dressers. The loop stiffnesses of centerless grinding machine are estimated based on the relative deformations between GW and RW caused by the grinding forces. And the simulated results illustrate that the concrete-filled bed has the considerable effect on the improvement of the structural stiffness of centerless grinding machine.
Development and Performance Evaluation of Polymer Micro-actuator using Segmented Polyurethane and Polymer Composite Electrode
Jung Young Dae ; Park Han Soo ; Jo Nam Ju ; Jeong Hae Do ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 180~187
This paper is focused on the development of the flexible electrode for disc-type polymer actuators using Segmented Polyurethane(SPU). This paper consists of two parts. The one is about the mechanical property such as elastic modulus. these parameters mainly affect behaviors of polymer actuators and the other is about the electro-chemical property such as the surface resistance of the composite electrode affects the strength of electrostatic force, results in the deformation of polymer actuators. The Young's modulus was measured by UTM. As result, by increasing the modulus of a body of polymer actuators, the maximum displacement of polymer actuators are decreased. The surface resistance of the electrode was measured by 4 point probe system. Compared with the conductive silver grease, the displacement of polymer actuators using carbon black(CB) composite electrodes is comparably small but CB composite electrode should be the practical approach for the improvement of the performance of all-solid actuators, compared with another types of electrode materials.
Friction Characteristics of Micro-scale Dimple Pattern under Mixed and Hydrodynamic Lubrication Condition
Chae Young-Hun ; Kim Seock-Sam ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 188~193
Surface texturing of tribological application is another attractive technology of friction reducing. Also, reduction of friction is therefore considered to be a necessary requirement for improved efficiency of machine. In this paper attempts to investigate the effect of density for micro-scale dimple pattern on bearing steel flat mated with pin-on-disk. We demonstrated the lubrication mechanism for a Stribeck curve, which has a relationship between the friction coefficient and a dimensionless parameter for lubrication condition. It is found that friction coefficient is depended on the density of surface pattern. It was thus verified that micro-scale dimple could affect the friction reduction considerably under mixed and hydrodynamic lubrication conditions from based on friction map. Lubrication condition regime has an influence on the friction coefficient induced the density of micro dimple.
Nanoscale Fabrication in Aqueous Solution using Tribo-Nanolithography
Park Jeong Woo ; Lee Deug Woo ; Kawasegi Noritaka ; Morita Noboru ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 194~201
Nanoscale fabrication of silicon substrate in an aqueous solution based on the use of atomic force microscopy was demonstrated. A specially designed cantilever with diamond tip, allowing the formation of damaged layer on silicon substrate easily by a simple scratching process (Tribo-Nanolithography, TNL), has been applied instead of conventional silicon cantilever for scanning. A slant nanostructure can be fabricated by a process in which a thin damaged layer rapidly forms in the substrate at the diamond tip-sample junction along scanning path of the tip and simultaneously the area uncovered with the damaged layer is being etched. This study demonstrates how the TNL parameters can affect the formation of damaged layer and the shape of 3-D structure, hence introducing a new process of AFM-based nanolithography in aqueous solution.
Development of Surface Finishing Methodology for the Laminated Pattern Removal of VLM-ST Parts
Lee Sang-Ho ; Kim Hyo-Chan ; Song Min-Sup ; Yang Dong-Yol ;
Journal of the Korean Society for Precision Engineering, volume 22, issue 2, 2005, Pages 202~209
A new effective thick-layered RP process, Transfer-type Variable Lamination Manufacturing using expandable polystyrene foam (VLM-ST) has been developed with thick layers and sloped surfaces. VLM-ST has the innate advantages by virtue of its working principle: high building speed, low cost for introduction and maintenance of VLM-ST apparatus, little staircase surface irregularities of parts. Despite these advantages in VLM-ST, the surface roughness of VLM-ST parts is still inadequate to be used as RP master patterns for rapid tooling (RT). This paper describes the systematic and effective methodology to remove the laminated pattern and improve the surface roughness for VLM-ST parts. From the results of surface finishing of VLM-ST parts, it can be seen that the laminated pattern is completely removed and the surface characteristics such as surface roughness, surface hardness, and paintability are improved.