• 소성∙가공
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• 제14권3호
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• pp.200-206
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• 2005

In general, a lot of small electrode is needed for making precision injection molds, such as cell phone mold and precision connector mold, because of the limitations of NC milling process. Those small electrodes usually have very simple shapes and the actual cutting time is so short, but many NC programs and set-up process, a very complicated and time consuming Job, are needed for each electrode. This paper deals the method for increasing the productivity of machining electrodes. In this work, the process standardization of machining electrode was done and special jig fer machining small electrodes was developed. Automatic tool path optimization software was also developed to minimize tool changing time. In addition, in-line cutting tool measuring system was adopted. The productivity of machining for small electrode has been increased up to $100\%$.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.201-204
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• 2006

A three-dimensional finite element (FEM) model has been developed to simulate the deformation due to bead on plate welding of curved plates with curvature in the weld direction. By using traditional method such as thermal-elastic-plastic FEM, the weld-induced deformation can be predicted accurately. However, this method is not practical approach to analyze the deformation of large and complex structures such as ship hull structures in view of time and cost. This study is classified from the aspect of equivalent load based on inherent strain near the weld line. Therefore, the residual deformation can be simply computed by elastic analysis. Further more, a practical solution is proposed to consider the contact between the plate and the positioning jig by judging the reaction forces of the jig at calculation step and the effect of the longitudinal curvature is closely considered.

• Progress in Superconductivity
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• 제3권2호
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• pp.218-223
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• 2002

The void volume fraction of cables is one of the effective parameters to characterize the joints of superconducting magnet. Because electrical resistance and cooling stability in the CICC (Cable-in-Conduit Conductors) joint are governed by the void volume fraction, it should be controlled constantly in the termination of cable. The change of cross-section shape in the cable was fecund during the unidirectional compaction of terminal sleeve. The non-uniform thickness of the sleeve after compaction is expected because the loading is not taxi-symmetric, and the plastic flow is also not axi-symmetric. The CICC was compacted from 45% void volume fraction to 15% by using two-piece compaction jig, which could be pressed mini-directionally. Commercial code, ABAQUS, was used to analyze the plastic flow in the sleeve during the unidirectional compaction. The increment of radius of curvature of compaction jig could minimize the change of the deformed shape of cables. The calculated results were agreed with the experimental observations.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.978-983
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• 2014

This research proposes a method to estimate the fatigue life of solid-state drive(SSD) due to the effect of dummy solder ball under forced vibration. Mechanical jig is developed to describe the SSD in laptop computer. The jig with SSD is mounted on a shaker, and excited by a sinusoidal sweep vibration within the narrow frequency band around the first resonant frequency until the SSD fails. A finite element model of SSD is also developed to simulate the forced vibration. It shows that the solder joints at the corners of controller package are most vulnerable components and that placing dummy solder balls at those area is effective method to increase fatigue life of SSD.

• 반도체디스플레이기술학회지
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• 제10권4호
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• pp.113-118
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• 2011

According to the high accuracy of semiconductor equipments, PCB substrate with much thin thickness is required. However, it is very difficult to sustain the PCB substrate without deformation in case of horizontal installation, due to low bending stiffness. In this research, new PCB process equipment with vertical installation has been developed in order to solve the problem of PCB substrate damage during etching process. As the main parts of etching system on PCB substrate, PCB substrate and JIG are analyzed through finite element method and experimental test. Through the analysis results of stress state, we could find the optimal JIG design to make the damage as low as possible.

• 한국생산제조학회지
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• 제19권4호
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• pp.570-575
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• 2010

This study is regarding development of an index table for antomation of welding process in impeller fabrication. A PLC, which is widely used for automation in industry, was also adopted as a controller for the index table because of it effectiveness, easy maintenance and repair. The index table consists of centering jig, blade jig, workbench, driving system and a controller. A touch screen was also prepaired as a man-machine interface to provide convenience for workers. Water jacket was installed inside the workbench to reduce thermal stress come from the welding. Temperature of the water jacket was kept constant to cool an impeller main plate effectively. The index table developed in this study convinces that it reduces the total welding time by 50% compared with the conventional process without the table.

• 한국산학기술학회논문지
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• 제8권6호
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• pp.1332-1336
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• 2007

본 논문의 목적은 대형 교량건설시 정밀시공을 보장하기 위하여 지그접합부를 3차원 정밀설계하고 지그접합 시 문제점을 해결하기 위하여 시뮬레이션에 의한 검증작업을 거쳐 구조를 개선한다. 지그를 제작하여 설치할 때 많은 예산이 소요되므로 문제발생을 방지하고 소요되는 시간과 예산낭비를 방지함으로서 건설엔지니어링의 효율성을 높이고 기술경쟁력을 향상시킨다.

• 반도체디스플레이기술학회지
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• 제18권4호
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• pp.75-80
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• 2019

One of the most critical aspects of the smartphone industry is the quality of the cover. And the vibrations of machining center are supposed to be the most dominant factors to damage the cover quality. In this study, structure of a machining center has been analyzed through experiments and computer simulations to figure out the main reasons of the vibrations. And the design alterations based on the analysis were applied to identify the effects of those alterations on the vibration suppression. The result shows that the design alterations can effectively suppress about 90% of the vibrations.

• 한국정밀공학회지
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• 제12권3호
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• pp.119-129
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• 1995

In this paper, the inclined endmilling process with a 3-axis machining center using inclined jigs is introduced for the purpose of reducing overall Dies/Molds machining time and improving the machining accuracies. In order to analyze the cutting mechanism of a given endmill more accurately, the unification of the cutting mechanism model of 3-different- kind endmills is carried out by using a nose radius as a parameter. By adding radial runouts as a parameter which influences on surface roughness, the superposition method which defines the effective cusp height superposing the cutter mark height and the conventional cusp height is advanced. And 3-D suface topography predicted in this paper looks like the surface normally observed in practice. Through machining experiments, the adequacy of the superposition method was confirmed.

• 중국학논총
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• 제61호
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• pp.49-75
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• 2019

Three types of plural forms are discovered in the ancient literature 《Chung-ui-jig-eon》: propositional plural markers placed in front of the main word - either noun or pronoun, postpositional plural markers placed behind the main word, and pro-/postpositional mixed plural markers. The Mongolian Rule in China during Yuan Dynasty caused the osmotic linguistic imperialism of the Mongolian over the Chinese language. Mongolian language - an Altaiian language which is postpositional - dominantly influenced the Chinese language - which is a propositional language. In addition, the previous usage of '輩', '等', '伟', '满' in Ancient Chinese, made it easier for '每' to be accepted and grammaticalized as a plural marker. The grammaticalization of '每' had been progressed through the reinterpretation of '每' in the structure of 'S(NP)+每+VP'. As a result, '每' had started to be widely used as a postpositional plural ending behind noun or pronoun, regardless of its position in the sentence.