• 한국기계가공학회지
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• 제8권3호
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• pp.68-73
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• 2009

This paper deals with the dynamic characteristics of the impeller shaft model which is the most important part in developing the resin mixing machine. The can is rotating by air motor in mixing machine. Then the end of shaft is fixed. The bearing support is to increase the fundamental natural frequency. The natural frequency analysis using finite element analysis software are performed on the imported commercial impeller shaft model. This paper presents calculated bearing stiffness of Soda, Harris and modified Harris formula considering contact angle according to bearing supported position. The most important fundamental natural frequency of the impeller shaft except bearing support is around 13.932 Hz. This paper presents one bearing and two bearings support position to maximize the 1st natural frequency. The maximized fundamental natural frequency is around 48.843 Hz in one bearing support and 55.52 Hz in two bearings support.

• 한국항공운항학회:학술대회논문집
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• 한국항공운항학회 2016년도 춘계학술대회
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• pp.95-98
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• 2016

It is true that Aircraft accident investigation organization of Republic of Korea does not have independent role structurally and administratively. Also, in the event of an aviation accident it does not take the appropriate response and post-institutional measures for victims and their families support. With aware of this fact and to improvement this research paper present approach direction and suggestion of issues and implications for those by researching the operational practices of the United State's Victim Family support.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 1999년도 추계학술대회 논문집
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• pp.209-210
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• 1999

오존 precursor인 NOx의 배출기준은 점차 강화되고 있고 NOx의 처리기술로는 선택적 촉매환원법 (Selective Catalytic Reduction; SCR)이 가장 널리 사용되고 있다. 국내 SCR 적용공정의 경우, 100% 수입에 의존하고 있어 support 촉매의 국산화가 절실히 요구되고있다. 이에 본 연구에서는 support로 섬유형 세라믹 필터를 사용하여 CuO, V$_2$O$_{5}$ 촉매를 담지시켜 NOx의 제거실험을 수행하였다.(중략)

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2008년도 추계학술대회 논문집
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• pp.78-79
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• 2008

• 한국국방경영분석학회지
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• 제26권1호
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• pp.70-88
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• 2000

In this research we consider a statistical model to estimate the optimal maintenance manpower of aircraft which we use at present. We design a multiple regression model, apply to three types of aircraft to estimate the optimal maintenance manpower of aircraft. This paper provides reasonable results about maintenance manpower of aircraft, and contributes accomplishment of mission for air and air support operations.

• 대한설비공학회지:설비저널
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• 제4권2호
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• pp.115-118
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• 1975

The constriction thermal resistance due to the floor supports in the Ondol floor heating system was investigated. The resistance has significant influence on the uniformity of floor surface temperature and heat flux through the floor. The heat flux decreased as much as $30\%$ for the geometry of the same channel and support areas.

• KSTLE International Journal
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• 제9권1_2호
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• pp.1-6
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• 2008

In this study is performed a complex lubrication analysis of a herringbone groove air journal bearing, which shows a big potential as an oilless bearing for a color wheel used as an original color source for a large DLP projection television and rotating at a rated-speed of 10,800 rpm. The Galerkin FE and perturbation methods are used for a lubrication analysis of the bearing. The effects of groove number, angle and depth and bearing clearance on the dynamic stability of the bearing are investigated in terms of the critical mass, and its equilibrium positions, stiffness and damping coefficients are calculated at various rotating speeds. Results have shown that the designed herringbone groove air journal bearing is quite suitable as a support bearing for the considered high-speed color wheel in terms of the complex lubrication performances of the bearing itself.

• Biomolecules & Therapeutics
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• 제10권4호
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• pp.281-286
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• 2002

In this study, we intended to get a preliminary data for establishing rat tracheal surface epithelial(RTSE) cell culture system as an experimental model for physiology and pharmacology of tracheal epithelial cells. Primary culture on the membrane support and application of the air-liquid interface system at the level of cell layer were performed. The cell growth rate and mucin production rate were measured according to the days in culture. The results were as follows: this culture system was found to manifest mucocilliary differentiation of rat tracheal epithelial cells, the cells were confluent and the quantity of produced and released mucin was highest on culture day 9, the mucin was mainly released to the apical side and tbe free $^3{H}$-glucosamine which was not incorporated to process of synthesis of mucin was left on the basolateral side. Taken together, we suggest that air-liquid interface culture system can be used as a substitute for immersion culture system and as an experimental model for in vivo mucus-hypersecretory diseases.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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• pp.81-88
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• 2001

To study the influence of the shape of contacting bodies (especially the end profile) on slip regime, wear test is conducted in the case of the contact between tube and support. Two different end profiles of the support are used such as truncated wedge and rounded punch. During the test, 10, 30 and 50 N are applied as normal force and slip displacement varies between 10-200 $\mu\textrm{m}$. The tube and the support specimens are made of Zircaloy-4 and a specially designed wear tester is used. Tests are carried out in air at room temperature. Wear on the tube is examined by measuring microscope. Partial and gross slip regimes are classified from the observed wear shape. Surface roughness tester is also used to measure the wear depth and contour, from which wear volume is evaluated. The transition from partial to gross slip is also investigated by investigating the considerable increase of wear volume. From the result, the boundary between the partial and the gross slip is newly determined in the conventional fretting map for the present specific contact configuration. Since the transition is related with the amount of energy dissipation from the contact surface so is wear, it is regarded that wear can be restrained by designing a proper shape of support.

• 우주기술과 응용
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• 제1권1호
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• pp.85-103
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• 2021

인간이 지구를 벗어난 우주 공간, 태양계 내의 천체(예, 달, 화성 등) 등에서 안전하게 생활하기 위해서는 반드시 환경제어 및 생명유지시스템 기술이 필요하다. 생명유지시스템은 일반적으로 공기관리시스템, 물정화시스템, 폐기물관리시스템 등으로 구성되며, 우주공간의 밀폐된 주거지에서 인간의 호흡 활동과 일상생활이 가능하도록 해준다. 본 논문에서는 우선 미국 항공우주국(NASA) 주도로 개발되어 온 생명유지시스템의 개발 동향을 소개하였다. 그리고, 현재 국제우주정거장(ISS)에서 운용 중인 생명유지시스템의 현황에 대하여 살펴보고, 국내 개발 동향도 조망해 보았다.