• 에너지공학
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• 제21권2호
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• pp.124-132
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• 2012

본 연구에서는 북측창을 가진 강의실 내의 불균형적인 실내 조도차이를 개선하기 위해 두 가지의 자연채광시스템을 적용하였을 경우에 대하여 Photopia를 이용한 성능 시뮬레이션을 수행하였다. 특히, 본 연구에서는 태양고도가 최고 $80^{\circ}$ 이르는 하지에 청천공 상태 하에서의 태양고도에 따른 각 시스템의 배광분포곡선을 구하고 이를 이용하여 실내 조도 등을 분석하였다. 작업면의 경우, 창측과 복도측의 평균 조도차가 1000lx를 초과하였는데 시스템 설치 후에는 그 차이가 상당히 줄어드는 것으로 나타났다. 광튜브 시스템 설치시 906lx에서 603lx로 감소하였으며, 디쉬형 시스템은 308lx까지 줄어들었다. 광튜브의 성능은 태양고도에 영향을 크게 받았으며 디쉬형 집광기는 지속적인 태양추적으로 인하여 태양고도에 관계없이 일정한 성능을 보여주었다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제27회 추계학술대회논문집
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• pp.367-370
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• 2006

Ballistic Range는 오래전부터 짧은 시간에 극도의 고압상태를 만들어낼 수 있기 때문에 고속 충격역학, 발사체 공기역학, 새로운 재료의 생성과 같은 다양한 공학 분야에서 사용되어왔다. 2단 경 가스총은 가장 넓게 사용되어지고 있다. 현재의 실험적 연구는 발사체 가상실험을 쉽게 수행할 수 있는 새로운 타입의 Ballistic Range를 개발하기 위해 진행되어져왔다. Ballistic Range은 고압튜브, 피스톤, 펌프튜브, 충격튜브, 발사튜브로 구성된다. 펌프튜브와 발사튜브사이에 충격튜브의 삽입의 효과는 조사중이다. 실험은 발사체 속도의 다양한 변수들의 의존성을 찾기 위해 수행되었다. 고압튜브압력, 격막파열압력, 발사체질량은 다양한 발사체 속도를 얻기 위해 변화를 주었다. 저자의 이론적 연구를 통해 얻는 결과값과 실험적 결과값을 비교해보기로 한다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.84-87
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• 2000

Square tubes used for vehicle structure components have an important role on keeping its stiffness and preserving occupant safety in vehicle collision and rollover in which it experience axial collapse, bending collapse or both. Bending collapse, which absorbs kinetic energy of the impact and retains a survival space for the occupant, is a dominant failure mode in oblique collision and rollover. Thus, in this paper, the bending collapse characteristics such as the maximum bending moment and energy absorption capacity of the square tube replaced by light-weight material were evaluated and presented. The bending test of cantilever tubes which were fabricated with aluminum, GFRP and aluminum/ GFRP hybrid by co-curing process was performed. Then the maximum bending moment and the energy absorption capacity from the moment-angle curve were evaluated. Based on the test results, it was found that aluminum/ GFRP hybrid tube can show better specific energy absorption capacity compared to the pure aluminum or GFRP tube and can convert unstable collapse mode which may occur in pure GFRP tube to stable collapse mode like a aluminum tube in which plastic hinge is developed.

• KIEAE Journal
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• 제7권6호
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• pp.119-126
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• 2007

In the field of composite structures, the use of carbon tube for the confinement of concrete has been arisen since 1990's. However, experimental and analytical studies were limited to those of reinforced concrete and concrete filled steel tube. The carbon tube provides excellent confinement capabilities for concrete cores, enhancing compressive strength and ductility of concrete significantly. The carbon tube has high tensile strength, light weight, corrosion immunity and high fatigue strength properties. Since carbon fiber is an anisotropic material, carbon tube could be optimized by adjusting the fiber orientation, thickness and the number of different layers. In this study, both experimental and analytical studies of axial and lateral behavior of full-scale CFCT (Concrete Filled Carbon Tube) columns subjected to monotonic axial load were carried out using Drucker-Prager theory. And, based on comparison results between experiment results and analytical results, k factor estimation was proposed for effective analysis.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.219-219
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• 2009

ceramic metal halide lamps are a subset of high intensity discharge lamps so named because of their high radiance These lamps weak ionized plasma in a fire-resisting but light transmissive wrapping by the corridor of current through atomic and molecular vapors. for commercial applications, For commercial applications, the conversion of electric power to light must occur with good efficiency and with sufficient spectral content throughout the visible (380-800 nm) to permit the light so generated to render colors comparable to natural sunlight. the purpose of this paper is to carry out a study on the variation of ageing time(2000 On/Off[hr]) on the performance of 150W CMH lamps. Experimental results show that the blackening by reacting W(tungsten)with I atomic has been created in the arc tube of an ageing lamp(2000 On/Off[hr]), the arc was unstable, and increased a lamp resistance made lamp voltage increases significantly. Also, Color temperature of the ageing lamp was moved by the losses of Ho with Dy atomics and by recombination of Na with I.

• 한국기계가공학회지
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• 제12권3호
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• pp.81-88
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• 2013

Recently, energy-saving technology is rapidly becoming a crucial issue for mankind due to the depletion of natural resources. From this perspective, every automobile manufactures are trying to develop light materials and to validate safety with environmental consideration. In this study, we developed clutch connector tube which is the parts of power transferring clutch with light materials to substitude for existing general steel materials. We also verified that the general steel materials can be replaced with nylon, fiberglass, stainless and plastic materials or not. As a result, we verified that the mixture of glass and nylon composite material can substitude the general steel.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2005년도 연구개발 발표회 논문집
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• pp.126-132
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• 2005

UV disinfection system allows the disinfection of municipal and industrial water and wastewater without the use of expensive chlorination and dechlorination techniques, labor intensive equipments In traditional ultraviolet systems the UV lamps are seperated from water by quartz sleeves. quartz is one of. the few materials that is virtually transparent to UV light, the UV lamp is placed inside the Quartz sleeve. UV light from the lamp is passed through the quartz and into the water, thereby providing disinfection. In fluoropolymer tube-used non-contact UV systems, the water flows through fluoropolymer plastic tubes. banks of UV lamps surround these tubes such that each tube gets exposed to ultra violet light from all sides. in non-contact design the lamps operates at almost constant temperature. this design is extremly efficient in the utilization of UV energy and superior to conventional contact- systems.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.634-639
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• 2004

Under light collision accidents, the energy absorption strategy for the coupler and expansion tube of the TTX(Tilting Train Express) initial design is established in the paper. Also, 1st shearing bolts are designed. When the absorbed energy of the coupler reaches its maximum, the connecting bolts between the coupler and the car body are sheared off not to transmit the impact force to the car body structure. To absorb more energy after the lst shearing bolts work, a expansion tube is designed conceptually and installed at the rear part of the coupler. Using Hyper-Mesh and LS-DYNA, pre/post processing and light collision analyses are preformed, respectively.

• 한국조명전기설비학회지:조명전기설비
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• 제10권4호
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• pp.53-61
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• 1996

광원에 대하여 서로 다른 여러 각도방향에서 광원을 바라볼 때 관측되는 광도 분포 및 재귀반사성능을 측정하기 위해 광도 분포 측정장치(배광측정기)를 제작하였다. 이 장치는 광원을 좌우로 360도, 상하로 $\pm$30도 회전 시킬수 있는 광원회전장치, 광검출기로 광전자증배관(PM Tube)을 쓰는 수광부 및 재귀반사성능 측정용 투광기와 제어 및 표시부로 구성되어 있다. 광도측정범위는 0.01~199900cd, 관측각범위는 0.2~1.5도 이고 광도의 측정오차는 $\pm$3%이다. 제작된 장치의 구조와 성능평가결과가 제기되었다.

• 전기학회논문지
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• 제57권12호
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• pp.2244-2248
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• 2008

High intensity metal halide discharge lamp performance, specifically the generated luminous flux and light color content, depends critically on the arc tube design. Factors influencing the design and consequent lamp efficacy include : lamp size, geometry, arc tube composition, fill chemistry, electrode design and excitation modes. Shaping of Polycrystalline Alumina(PCA) can be realized by conventional ceramic processes. Several processes are applied nowadays. Well-known in the ceramic high pressure field for decades are the pressing and the extrusion method. Newly developed slurry and precious forming technologies give the one-body seamless tubes, which improve thickness uniformity and lighting performance. Now, we reported some optical properties with different arc tube structures of ceramic metal halide lamps.