• 대한기계학회논문집
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• 제16권6호
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• pp.1064-1074
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• 1992

본 연구에서는 제품에 분할선을 입력하여 상, 하판 금형을 만든 후 제품의 추 출을 방해하는 금형의 면들을 간섭검사를 통하여 찾아내는 프로그램을 개발하였다. 그리고 찾아낸 간섭면들을 이용하여 금형 설계자가 적합한 형상의 사이드 코어를 설계 할 수 있도록 설계과정을 CAD화 하였다.물론, 내부적으로는 사이드 토어의 생성과 동시에 금형의 형상도 수정되도록 프로그램 되어있다. 이러한 일련의 과정은 Fig.2 와 같이 나타낼 수 있는데 앞으로 2장에서는 금형의 생성 및 간섭면 검색 과정을 다루 고 3장에서는 사이드 코어의 설계 및 금형의 수정과정을 단계별로 자세히 설명하도록 하겠다. 그리고 결론에서는 현재 갭ㄹ한 프로그램의 효용 및 적용 범위, 문제점 및 개선 방안 등에 대해서 논의해 보겠다.

• 한국정밀공학회지
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• 제21권4호
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• pp.39-47
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• 2004

In mold machining, there are many concave machining regions where chatter and tool deflection occur since MRR(material removal rate) increases as curvature increases even though cutting speed and depth of cut are constant. Boolean operation between stock and tool model is widely used to compute MRR in NC milling simulation. In finish cutting, the side step is reduced to about 0.3mm and tool path length is sometimes over loom, so Boolean operation takes long computation time and includes much error if the resolution of stock and tool model is larger than the side step. In this paper, curvature of CL (cutter location) surface and side step of tool path is used to compute the feedrate for constant MRR machining. The data structure of CL surface is Z-map generated from NC tool path. The algorithm to get local curvature from discrete data was developed and applied to compute local curvature of CL surface. The side step of tool path was computed by point density map which includes cutter location point density at each grid element. The feedrate computed from curvature and side step is inserted to new tool path to regulate MRR. The resultants were applied to feedrate optimization system which generates new tool path with feedrate from NC codes for finish cutting. The system was applied to the machining of speaker and cellular phone mold. The finishing time was reduced to 12.6%, tool wear was reduced from 2mm to 1.1mm and chatter marks and over cut on corner were reduced, compared to the machining by constant feedrate. The machining time was shorter to 17% and surface quality and tool was also better than the conventional federate regulation using curvature of the tool path.

• 한국잠사곤충학회지
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• 제13권2호
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• pp.151-154
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• 1971

In the silkworm egg production, cutting of the cocoon's edge formed by silkworms forced to aid the emergence, and emergence is related to the amount of alkaloid liquid in the sucking stomach in certain varieties. In this study, there was no difference between cutting of portion and sex, and no significant between cutting of both sides and one side cocoons when comparing their emergence ratio. Expenditures and emergence ratio between both sides and one side cutting off must be studied in coming future.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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• pp.783-786
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• 2003

A simple fabrication method of self-aligned ridge waveguides with dielectric side buffers is demonstrated on +Z- cut LiNbO$_3$. The ridge waveguide is fabricated by a combination of the annealed proton exchange process and the proton-exchanged wet etching technique. The self-aligned process is achieved by wet etching of aluminum.

• Animal cells and systems
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• 제1권2호
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• pp.313-316
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• 1997

Thomas'fruit-eating bat, Artibeus watssoni, is known to alter leaves of a wide variety of tropical plants to construct tent roosts. On Barro Colorado Island and Gigante Peninsula in the canal zone, Panama, A. watsoni is found to use the black palm, Astrocaryum standleyanum, as its tent plant. Bats cut the first five to ten pinnae from the proximal side of the terminal blade and chew additional four to nine pinnae without severing their central veins. The distance from the frond rachis to the cut decreases distally leaving an inverted V-shaped cut path. The distal portions of the bifurcated blade are then collapsed and folded to form the'bifid'tent with an inverted boat-shaped cavity underneath. All tents were in fronds of trunkless juvenile plants.

• 동력기계공학회지
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• 제12권3호
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• pp.32-37
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• 2008

The present work aims to determine the overall pressure losses in the shell from the point of entry of the fluid to the outlet point of fluid of shell and tube heat exchanger. The main contribution of the present work is concerned with calculating the pressure drop in the interior section and window section. Shell-side flow velocity distributions have been evaluated. We assume that the shell-side fluid is turbulent. The calculation procedure is based upon the Delaware method. Evaluation of pressure drop on the shell side will be helpful for a designer or manufacturer of a heat exchanger.

• 한국기계가공학회지
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• 제2권1호
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• pp.39-44
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• 2003

In the present industry, there are necessary to cut not only iron metals but also non-ferrous metals such as aluminum, brass, plastic and wood(Paulownia) therefore it had been made the studies of non-ferrous metals by many scientists. The purpose of this study is to conduct the basic experiment about influencing of the feedrate adjustment and the change of the side rake angle at turning of non-ferrous metals. As the results, the surface roughnesses and Cutting force adjustments were on the decrease with a side-rake angle and feedrate diminution in the case of the plastic, brass, aluminum, and paulownia.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.929-934
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• 1997

In the present industry, there are necessary to cut not only iron metals but also non-ferrous metals such as aluminum, brass, plastic and wood(Paulownia).therefore it had been made the studies of non-ferrous metals by many scientists. we hope this kind of study will continue. The purpose of this study is to conduct the basic experiment about influencing of the feedrate adjustment and the change of the side rake angle at turning of non-ferrous metals. As the results, the surface roughnesses and Cutting force adjustments were on the decrease with a side-rake angle and feedrate diminution in the case of the plastic, brass, aluminum, and paulownia

• 한국공작기계학회논문집
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• 제13권6호
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• pp.17-22
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• 2004

A study for investigating the effects of the cutting conditions (radial depth of cut feed per tooth) and the number of tooth on the side wall of prismatically milled workpiece is described. This study is available not only for understanding the geometrical characteristics of the end milled side wall but also for finding the optimal cutting conditions. In this work, the side wall geometry was characterized by the straightness and the location of maximum peak point. Through this study, it was revealed that the geometrical characteristics of the end milled side wall are strongly related to the material removal per tooth and the number of tooth.

• 한국지반환경공학회 논문집
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• 제5권4호
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• pp.73-79
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• 2004

도로주변 절토사면 상부에 설치되는 산마루측구는 강우시 상부로부터 흘러내려오는 지표수를 원활히 배수시켜, 절토면으로 유입되는 것을 방지하기 위해 설치한다. 그러나, 산마루측구 설치시 시공여건상 품질관리가 어려워, 절토면 배면으로부터의 지표수를 원활히 배수시키지 못하는 문제점을 안고 있다. 따라서, 본 논문에서는 비탈면 상부에 설치된 산마루측구의 기능을 지반 및 지형조건, 강우조건에 따라 비탈면 안정성에 미치는 영향을 평가함으로써, 현재 설계 시공되고 있는 산마루측구의 설치 적정성을 평가하였다. 평가결과 산마루측구는 평균적으로 강우시 약 3%의 안전율 증대효과가 있는 것으로 검토되었다.