• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.231-232
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• 2002

Various methods that utilize erosion rate measurement of standard cannon, 155mm Howitzer M185, as reference, are being used to calculate erosion rate of an interested unknown cannon tubes. We know ten measured erosion values of the standard cannon from 391 rounds to 4.000. An approximate function fitting these value s is derived. The new erosion equation is also suggested and computer simulations arc presented.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.19-21
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• 2002

Electroded lamps operated at a high enough frequency can usually be modeled for the purpose of ballast design, as a resistor. Electrodeless fluorescent lamps include other components such as the arc tube's inductance. But that's impedance is small and so will be neglected in this paper. So, electrodeless fluorescent lamps is modeled as a resistor. A SPICE compatible model was developed for an electrodeless fluorescent lamp(OSRAM SYLVANIA ICETRON/ENDURA 150W).

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.227-228
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• 2012

In contemporary architectural practice, flat sections and plan drawings are no longer a primary means of representation and communication with participants. A typical building design has an ornamental exterior wall system and a roof system that should have water-proof quality and drainage function. By comparison, distinction between exterior wall and roof are unclear in freeform buildings, and they are integrated into a concept of a building envelope. This study is to propose 3D coordinate control technology for freeform structure by CNC curved tube method in order to develop a BIM-based envelope design and construction method for freeform building. Because a much wider freeform building construction can be achieved with correct 3D data and easy-to-implement in construction field, the proposed 3D coordinate control technology is highly recommended for practical use instead of the conventional CAD system.

• Corrosion Science and Technology
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• 제9권3호
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• pp.122-128
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• 2010

The corrosion of the flexible tube in the automobile exhaust system is caused by the ambient water and chloride ions. Since welding is one of the key processes for the flexible tube manufacturing, it is required to select a proper welding method to prevent the flexible tube corrosion and to increase its lifetime. There are many studies about the efficiency of the welding method, but no systematic study is performed for the effect of welding method on the corrosion property of the austenitic stainless weldment. The aim of the present study is to provide information on the effect of two different welding methods of TIGW (tungsten inert gas welding) and PAW (plasma arc welding) on the corrosion property of austenitic stainless steel weldment. Materials used in this study were two types of the commercial austenitic stainless steel, STS321 and XM15J1, which were used for flexible tube material for the automotive exhaust system. Microstructure was observed by using optical microscopy (OM) and scanning electron microscopy (SEM). To evaluate the corrosion behavior, potentiodynamic and potentiostatic tests were performed. The chemical state of the passive film was analyzed in terms of XPS depth profile. Metallurgical analysis show that the ferrite content in fusion zone of both STS321 and XM15J1 is higher when welded by PAW than by TIGW. The potentiodynamic and potentiostatic test results show that both STS321 and XM15J1 have higher transpassive potential and lower passive current density when welded by PAW than by TIGW. XPS analysis indicates that the stable $Cr_2O_3$ layer at the outermost layer of the passive film is formed when welded by PAW. The result recommends that PAW is more desirable than TIGW to secure corrosion resistance of the flex tube which is usually made of austenitic stainless steel.

• 조명전기설비학회논문지
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• 제18권5호
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• pp.9-15
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• 2004

메탈핼라이드 램프의 가장 큰 단점중 하나는 아크튜브가 뜨거운 상태에서는 순시 재점등이 불가능하다는 것이다. 메탈핼라이드 램프의 점등중 고온의 아크튜브는 초기 램프가 차가운 상태에서의 방전 전압보다 재점등 방전전압이 높아 재점등 시키는데 압력과 온도가 감소되어지는 약5분정도의 시간이 소요 된다. 만약 램프가 뜨거운 상태에서 재점등시키려면 램프전극 양단에 약20[kV] 이상의 높은 전압펄스를 공급해야한다. 따라서 이러한 목적의 전자식 안정기는 EMII필터, PFC회로, 플라이백 컨버터, 하프브리지 인버터, 고전압 이그나이터 회로로 구성되는데 이것은 순시점등은 물론 램프가 뜨거운 상태에서도 20[kV]의 전압으로 램프를 점등/재점등 할 수 있다.

• 전기학회논문지
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• 제58권12호
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• pp.2446-2452
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• 2009

A Ceramic Metal-halide lamp is achieved by adding multiple metals to a basic mercury discharge. Because the vapor pressure of most metals is very much lower than mercury itself, metal-halide salts of the desired metals, having higher vapor pressures, are used to introduce the material into the basic discharge. The metal compounds are usually polyatomic iodides, which vaporize and subsequently dissociate as they diffuse into the bulk plasma. Metals with multiple visible transitions are necessary to achieve high photometric efficiency and good color. Compounds of Sc, Dy, Ho, Tm, Ce, Pr, Yb and Nd are commonly used. The maximum visible efficacy of a Ceramic Metal Halide lamp, under the constant of a white light source, is predicted to be about 450lm/W. This is controlled principally by the chemical fill chosen for a particular lamp. Current these lamps achieve 130lm/W and these life time are the maximum 16,000[hr]. So factors of performance lower are necessary to improve lamp performance. In this paper, we analyzed factors of performance lower by accelerated deterioration test. The lamp was operated with short duration turn-on/turn-off procedure to enhance the effect due to electrode sputtering during lamp ignition. The tested lamp that was operated with a longer turn-on/off(20/20 minutes) showed blackening, changed distance between electrodes and lowered color rendering & color temperature by losses of Dy at 421.18nm, I at 511nm, T1 at 535nm and Na at 588nm compared with the new lamp.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.388-389
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• 2009

The use of arc tubes made of ceramic material further enhanced some of the metal halide lamp's properties. These properties translate into higher efficacy with better color rendering, stable color through lamp long life. Recently, due to an increase in the application of the ceramic metal-halide lamp, the study for the property etc. according to Ballast's driving scheme and the study for arc tube material, optimization of gas and so on are being proceeded to improve the property of the lamp. Especially, to control ceramic metal-halide lamp, the vigorous study and practical use with respect to Electronic Ballast, which has been improved in the disadvantages of the conventional Magnetic Ballast are made. In this paper, Electrical characteristics and gas insulation destroy time are analyzed by comparing magnetic ballast with electronic ballast.

• 대한화학회지
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• 제40권3호
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• pp.196-201
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• 1996

혈액 중 미량 카드뮴 분석에 전기로 장치가 부착된 원자 흡수 분광광도계(GFAAS)를 사용하였다. 시료를 1% Triton X-100으로 10배 희석시킨 다음 회화 온도 500$^{\circ}C$에서 Fork platform흑연 튜브를 사용하여 분석하였으며, 결과 처리는 피크 면적법과 피크높이법으로 비교하였다. 양쪽 모두 우수한 값을 얻을 수 있었으며 SH 바탕보정법과 $D_2$ 바탕보정법에 의하여 얻은 검출한계는 각각 0.02ng/mL와 0.01ng/mL이고 상대 표준편차는 1.0ng/mL 종도에서 5%이내였다. 분석의 정확성을 평가하기 위하여 노르웨이 Nycomed Pharma사의 Seronorm (Trace Elements Whole Blood)을 분석, 비교 검토 하였다.

• 한국조명전기설비학회지:조명전기설비
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• 제5권4호
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• pp.35-42
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• 1991

Recently, HID lamps have been considered as important in regard to the trend of energy saving, and increasingly and diversely used in various ways. This paper will show the simulating models concerning high-pressure arc discharge system directly applicable for its design and manufacture, and analyze its various characteristics. For warm-up characteristics, the evaporating process of inner atoms is described in terms of second-order differential equation: for the thermal conduction from are axis to discharge wall and outer bulb, its transfer process is introduced according to five first-order differential equations. Under the steady state satisfying LTE, the time-variant characteristics are suggested by means of time-dependent energy balance equation derived from fluid equations, approximation of radiation energy and material functions in the discharge tube. The simulating models concerning these equations are then applied for high-pressure mercury lamp.

• 전기학회논문지
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• 제56권3호
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• pp.531-537
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• 2007

This paper presents a new method for determining L, Cs, and Cp in a series parallel resonant inverter. This inverter is suitable for driving high-intensity discharge (HID) lamps. The operating frequency is selected to avoid acoustic resonances which are governed by the size and shape of the arc tube. L, Cs and Cp, are chosen to satisfy the ignition and steady state requirements of the lamp. Equations are developed to analyze the starting condition and steady state operating condition of the lamp. For the prototype ballast for a 250W Metal Halide Lamp, experimental results are presented in order to validate the proposed method.