• Transactions of Materials Processing
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• v.9 no.3
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• pp.293-303
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• 2000

Recent developments of Fe technology make it possible to apply CAD/CAE/CAM techniques successfully to the stamping die design among the automotive parts industries. Those successful applications are greatly attributable to the development of commercial S/W. Up to now most commercial S/W for the analysis of sheet metal forming is based on the dynamic explicit algorithm. The main characteristics of dynamic explicit algorithm is that there is no convergence problem if the time increment is taken less than the stability limit. The stability of the analysis is guaranteed in the commercial code, since the adequate time increment is computed from the so called "Courant Condition". However excess computing time is often pointed out in the dynamic explicit analysis according to the characteristics of process parameters taken. In the study, various parameters that may affect the stability and the method how to improve computational efficiency of analysis have been investigated.estigated.

• The Microorganisms and Industry
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• v.20 no.1
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• pp.50-52
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• 1994

Ultrastructural observations of mycelial and tissue phase with dimorphic fungal pathogen Coccidioides immitis were studied by electron microscopy of thin sections. 1. In mycelial phase of C.immitis contains normal cell components such as nucleus, mitochondria, endoplamsic reticulum, intracytoplasmic membrane system, cell wall and cell membrane as observed in the other encaryotic cells. 2. In tissue phase of C. immitis was larger than mycelial phase in cell size and observed much more vacuoles than mycelial phase. 3. In the contrast of mycelial phase of C. immitis, the tissue phase of cells were observed fibril form of capsular layer.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.87-88
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• 2011

전기 자동차는 내연기관 차량을 대체할 차세대 그린카의 대표 차종으로 부각되고 있다. 전기 자동차가 상용화되기 위해서는 전기자동차 자체의 성능뿐만 아니라 충전 인프라 발전이 함께 이뤄져야 한다. 현재 개발된 전기 자동차의 경우 충전 시간이 긴 반면 주행 거리가 짧기 때문에 효용성이 크게 떨어진다. 따라서 충전 시간을 최대한 단축 시키기 위한 급속 충전 시스템 개발이 활발하게 진행되고 있다. 본 논문에서는 전기 자동차용 급속 충전기에 적용되는 실제적인 DC-DC 컨버터를 ATPDraw/MODELS를 이용해 모델링하고 검증하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.24-24
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• 2003

최근 자동차 산업이 발달함에 따라 철강업계와 자동차 회사에서는 전에 많이 사용하던 내연 무도금강판 대신 부식에 저항력이 강한 도금강판을 사용한 이후로 냉연강판의 가공 시에 야기되지 않았던 많은 문제점들이 나타났다 자동차용 강판의 경우 판재의 체적에 비하여 금형과 판재의 접촉면적이 큰 프레스 공정에서는 판재의 표면에 작용하는 마찰력의 크기가 판재의 스탬핑 성형성에 큰 영향을 미친다. 이는 마찰특성이 비록 재료고유의 성형한계에서는 영향을 미치지 못하나 스탬핑 공정에 있어서 금형과의 접촉면에서 마찰력의 크기가 패널의 변형률분포를 변화시켜 스탬핑 성형성에 큰 영향을 주는 것이다. 따라서 본 연구는 자동차용 도금강판의 표면 거칠기에 따른 판재의 표면 마찰 특성 변화를 알아보았다. 소재의 기계적 특성 측정은 UTM을 사용하였고, 도금층은 XRD, SEM을 이용하여 상분석 하였으며, 표면 거칠기는 AFM(Atomic Force Microscope), SJ-400(Mitutoyo)을 사용하여 표면 거칠기를 측정하였다. 또 드로잉 하중을 비드부에서의 굽힘-굽힘 풀림 소성변형에 의한 변형력 성분과 마찰력 성분으로 분리하여 강판의 쿠롬 마찰계수를 DBS(Draw bead simulation)로 측정하였다.

• Journal of Institute of Convergence Technology
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• v.3 no.1
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• pp.25-29
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• 2013

The purpose of this paper is to determine the fuel change and weight change impact on the fuel economy and emission characteristic of ICE (Internal Combustion Engine) vehicle. According to fuel type, fuel consumption and emission characteristics were measured and fuel used in this paper was gasoline, diesel, and LPG. Four vehicles with different weight were tested and the fuel economy were compared and analyzed by using scatter graph. Test was carried out using chassis dynamometer, CVS (Constant Volume Sampler), and emission measurement system. Diesel vehicle less emited $CO_2$ compared to gasoline and LPG. Even if same $CO_2$ between gasoline and LPG, there are difference fuel economy depending on carbon proportion of specific fuel. The heavier weight of vehicle, the worse of fuel economy and Better fuel economy performance on highway driving mode.

• Korean Journal of Human Ecology
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• v.14 no.3
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• pp.467-473
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• 2005

The integrative Internet program was developed for the selection of optimal brassiere components according to the breast types of middle-aged women. In this program, a customer is classified into a certain group through three steps of a discriminant analysis. Three variables used in the analysis include breast volume, radii of curvature of under-breast curve, and a distance between inner breast points. Using individual data of three variables, the optimal brassiere components, i.e. brassiere cup size, curvature of front panel and wire, distance between cups, are suggested for each customer. Discrimination of breast types using only 2D measurements is also included for those who do not have easy access to a 3D measurement device.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.274-276
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• 2009

최근 화석연료의 연소로 인해 발생되는 이산화탄소에 의한 환경오염이 크게 대두가 되고 있으며, 특히나 내연기관 자동차의 배출가스는 이산화탄소의 배출량이 매우 높은 실정이다. 따라서 정부에서는 친환경자동차 분야를 하나의 성장사업으로 선정하였으며, 이에 대한 많은 연구 개발이 진행 중에 있다. 본 논문에서는 출퇴근용으로 사용할 수 있는 근거리 전기자동차용 10kW급 BLDC 모터 제어기 개발에 대하여 제안을 한다. 제안된 근거리 전기자동차용 10kW급 BLDC 모터 드라이브 제어기는 한정된 공간 및 배터리 전원에서도 고토크, 고출력, 고효율, 경량화의 장점을 가지도록 개발을 하였다. 또한, BLDC 모터는 회전자 위치 정보가 필수적으로 요구되기 때문에 다양한 위치 센서를 사용할 수 있도록 홀센서, 엔코더, 레졸버를 사용할 수 있도록 모터제어기를 개발 하였다. 제안된 방식의 타당성 검증을 위해 PSIM을 이용하여 시뮬레이션 수행하였으며, 10kW급 BLDC 모터 드라이브 제어기를 제작하여 성능을 검증하였다.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.1
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• pp.96-99
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• 2010

This paper presents evaluating procedure for engine generator operated over 13 years which are usually installed at the island and therefore, isolated to the main distribution line. To decide continual operation of the generator, their diagnosis results should guarantee safety running. So the determination of criteria for continual usage or replacement is essential for economical and reliable maintenance. We present all the courses of evaluating the condition which includes the processes from acquiring basic data to comprehensive determination of generators. All the test was applied to serial number 3 generator in Jodo Engine Power Plant.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.268-272
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• 2016

A brush-less type synchronous generator is driven by an internal-combustion engine that is used for emergency source. This kind of generator has to maintain output voltage in a range of some degree under the abrupt load irregular conditions such as a full load trip. This paper suggests a suppression method of increasing the output voltage over the rating. Automatic voltage regulator detects excessive rising of output voltage of the generator and supplies the signals to a switch installed in the rotating exciter through the photo-coupler. The current of main field rapidly decreases by additional resistor of the main filed circuit. Therefore, the output voltage of the generator is maintained effectively. The experimental results verified that the excessive value of the output voltage is limited in the range of 7% of the rated voltage.

• Journal of Advanced Marine Engineering and Technology
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• v.15 no.2
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• pp.44-52
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• 1991

The crankshaft system of engine is a complex vibratory object and its vibration modes are consisted of torsional, axial and their coupled vibration. Among them, the torsional vibration causes engine noise as well as serious fatigue faillures of crankshaft. If the troules of noises and crankshaft strength are forecasted by torsional vibration calculation in the design atage of crankshaft, the torsional damper is adopted as the final countermeasure. In this paper, some computer program to calculate crankshaft torsional vibration of engine are developed and with developed programs, an efficient rubber-viscous damper for automobile and with developed programs, an efficient rubber-viscous damper for automobile engine is designed and manufactured, and then it is fitted on the actual automobile engine to confirm its calculated efficiency. By comparing the measured result (with damper and without damper) with the calculated one, the reliability of developed computer programs and the performances of manufactured damper are confirmed.