• Journal of the Korean Vacuum Society
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• v.16 no.6
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• pp.483-488
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• 2007

Current feeder system (CFS) for Korea superconducting tokamak advanced research(KSTAR) project plays a role to interconnect magnet power supply (MPS) and superconducting (SC) magnets through the normal bus-bar at the room temperature(300 K) environment and the SC bus-line at the low temperature (4.5 K) environment. It is divided by two systems, i.e., toroidal field system which operates at 35 kA DC currents and poloidal field system wherein 20$\sim$26 kA pulsed currents are applied during 350 s transient time. Aside from the vacuum system of main cryostat, an independent vacuum system was constructed for the CFS in which a roughing system is consisted by a rotary and a mechanical booster pump and a high vacuum system is developed by four cryo-pumps with one dry pump as a backing pump. A self interlock and its control system, and a supervisory interlock and its control system are also established for the operational reliability as well. The entire CFS was completely tested including the reliability of local/supervisory control/interlock, helium gas leakage, vacuum pressure, and so on.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.97-98
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• 2006

This study deals with the Transmission Error of gear tooth profile by modifying a Profile and lead of a surface of Tooth. First, we experimentally confirmed that the Transmission Error is a synthesis of the sliding Velocity between both gears. Since various types of Transmission errors appear in the experiments, we introduced definition of Transmission Error and The Optimism Design by modifying a surface parameters The test stand's performance is then evaluated through a series of multiple torque transmission error tests. Comparisons are made between data recorded before and after the test stand's redesign, and subsequently repeatability studies are performed to verify the veracity of the measured data. Finally, the experimental results are compared to the analytical predictions of two different gear analysis programs.

• Journal for History of Mathematics
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• v.23 no.4
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• pp.17-30
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• 2010

The aim of this paper is to classify mathematical revolutions by discussing the concept of revolution, and to suggest criteria to judge mathematical revolutions. I examine the relation between the types and the criteria of mathematical revolutions, and explore what types of revolutions several instances of changes in mathematical knowledge are.

• CDE review
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• v.3 no.2
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• pp.52-58
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• 1997

제품 개발 환경을 자세히 들여다보면, 고객의 요구 또는 창조된 새로운 제품의 컨셉(Spec)을 사람(개발자)이 도구(설계경험, CAD)를 이용해서 업무수행절차(업무처리규정, 부서별 역할)에 따라 제품을 정의(모양, 크기, 구조)하는 것을 설계행위로 볼 수 있고, 이러한 활동의 결과로써 도면 Mock-up, 각종 Document가 만들어지고 이러한 매체가 부서간, 업무공정간 의사소통의 수단으로 이용되고 있다. 여기서 CAD를 없애서는 안될 개발의 도구로 인식하고 이용하는데, 일반적으로 경쟁력있는 제품을 개발하기 위한 노력의 일환으로 3차원 CAD시스템을 도입하여 적용해 오고 있다. 현재의 3차원 CAD시스템들은 공통적으로 솔리드(Solid) 근간에, FEATURE 개념을 수용하면서 PARAMETRIC 또는 VARIATIONAL 모델링 기법을 채택하여 설계자들에게 다양한 기능을 제공하고 있다. 그러나 3차원 CAD 시스템을 적용하여 만족할 만한 결과를 얻어내기란 간단한 문제가 아니다. 본 고에서는 당 사업장에서 개발한 무선전화기 및 FAX에 3차원 설계를 적용한 사례를 중심으로, 3차원 설계에 대한 허와 실을 살펴보고 3차원 설계가 나아가야 할 방향에 대해 생각해 보고자 한다. 참고로 당 사업장은 디자인, 기구설계, 금형설계까지는 I-DEAS, CAM 작업은 CATIA를 이용하고 있다.

• Korean Journal of Computational Design and Engineering
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• v.11 no.5
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• pp.344-350
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• 2006

A method for extracting material information on sheet metal parts from an assembly model is proposed. In order to estimate the cost and order the required sheet metals, their outline profiles, thicknesses, quantities, and etc. are needed. The proposed method consists of two steps: First, sheet metal parts are selected through a feature recognition process from an assembly model. Then, some geometric information for the parts is calculated. In the later step a flattening process of bent parts is included. The method is implemented on a commercial CAD/CAM system Unigraphics with API routines and applied to steam turbine generators and large scale boilers.

• Proceedings of the CALSEC Conference
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• 1999.07a
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• pp.327-333
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• 1999

섬유산업의 환경이 과거의 공급자 중심의 생산, 유통체제(Product out)에서 소비자 중심의 체제(Market In)로 바꾸면서 소비자의 의식과 입장에 서서 상품을 생산하고 유통하는 것을 요구하고 있다. 이러한 요구는 눈부시게 발전하는 정보통신기술을 이용하여 혁신적인 생산 유통의 Innivation인 Quick Response체제를 등장케하는 배경이 되었다. QR은 생산, 유통관계의 거래당사자가 협력하여 소비자에 대하여 Right Product, Right Pla ce, Right Price, Right Time, Right Quantity를 실현하는 것을 목표로 표준상품코드와 ED I, CALS표준등의 요소를 갖춰 기업간, 기업과 소비자가 전자거래(EC)를 실현하여 생산, 유통의 합리화를 이룸으로 그 성과를 생산자, 유통관계자, 소비자가 서로 분배하는 것이다. 또 광역의 정보네트워크를 이용하여 원부자재 업계부터 소매업계까지 유기적으로 통합, 정보의 공유화, 신속화를 꾀함으로서 부가가치를 창출해 내는 것이다. 이같은 산업체간의 정보 공동이용시스템 구축은 대기업과 중소기업의 협력사업이 가능할 뿐만 아니라, 섬유의류산업의 고질적인 병폐로 지적되어온 제품의 리드타임을 해결하는 획기적인 전환점이 될 수 있다. 따라서 섬유산업의 원부자재부터 원사, 직물, 어패럴, 유통에 이르는 전과정을 통일된 표준을 도입하여 전업계가 공동 사용케하고, 그것을 정보시스템과 접목, 전자거래를 실현하기 위한 방안을 제시함.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.3
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• pp.150-157
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• 1996

In this paper, to develop a smart CAD/CAM system for systematically performing from the 3-D solid shape design of products to the CNC cutting operation of products by a machining center, a B-Rep solid modeler is realized based on the half edge data structure. Because the B-Rep solid modeler has the various capabilities related to the solid definition functions such as the creation operation of primitives and the translational and rotational sweep operation, the solid manipulation functions such as the split operation and the Boolean set operation, and the solid inversion function for effectively using the data structure, the 3-D solid shape of products can be easily designed and constructed. Also, besides the automatic generation of CNC code, the B-Rep solid modeler can be used as a powerful tool for realizing the automatic generation of finite elements, the interfer- ence check between solids, the structural design of machine tools and robots and so on.

• Journal for History of Mathematics
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• v.19 no.1
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• pp.43-54
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• 2006

The purpose of this paper, followed by 'Nature$\cdot$Human, and Golden Section I ', is to study aesthetic consciousness, mentality model and body proportion of human, and the golden section applied to architecture and hand axe of stone age. In particular, handaxes of one million years ago have shown that they had critical competency to the basis of art and mathematics in the future. Furthermore, without pen, paper and ruler, the existence of mentality model made fundamental conversion of mathematics possible. Different sizes of handaxes were made by maintaining the equal golden section. This was the first example in relation to the principle mentioned in 'Stoicheia' by Euclid which was published hundred thousands of years later.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.2
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• pp.41-45
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• 2015

RtMLF (Routable Molded Lead Frame) based on molded substrate has been developed to maximize advantages of both leadframe product which has high thermal and electrical performance and laminate product which accommodates more I/O count and keeps fan-in/fan-out design flexibility. Due to its structural features, RtMLF provided excellent thermal and electrical performance which was confirmed with simulation. The RtMLF samples were manufactured and its reliability analysis was done to evaluate the opportunities of the production and application.

• Journal of the Korean institute of surface engineering
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• v.36 no.6
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• pp.491-499
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• 2003

Copper-based leadframe sheets were oxidized in a hot alkaline solution to form brown-oxide layer on the surface and molded with epoxy molding compound (EMC). The brown-oxide-coated leadframe/EMC joints were machined to form sandwiched double-cantilever beam (SDCB) specimens and sandwiched Brazil-nut (SBN) specimens for the purpose of measuring the fracture toughness of leadframe/EMC interfaces. The SDCB and the SBN specimens were designed to measure the fracture toughness of the leadframe/EMC interfaces under nearly mode-I loading and mixed-mode (mode I ＋ mode II) loading conditions, respectively. Fracture surfaces were analyzed by various equipment such as glancing-angle XRD, SEM, AES, EDS and AFM to elucidate failure path. Results showed that failure occurred irregularly in the SDCB specimens, and oxidation time of 2 minutes divided the types of irregular failures into two classes. The failure in the SBN specimens was quite different from that in the SDCB specimens. The failure path in the SBN specimens was not dependent on the phase angle as well as the distance from tips of pre-cracks.