• 한국항공운항학회지
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• 제20권2호
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• pp.7-12
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• 2012

A landing gear absorbs the impact energy during the touchdown and it generally consists of an oleo-pneumatic shock absorber and structural components. It should be designed not only to satisfy the static and fatigue strength requirements but to have the sufficient shock absorbing efficiency. The design loads and shock absorbing performance are to be validated by tests, which is required by MIL Spec and FAR, etc. This paper presents the development procedures from the design requirements to the qualification tests and technical points to be considered, with examples of the helicopter landing gear development.

• 공업화학
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• 제20권4호
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• pp.437-442
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• 2009

$TiO_2$, $Al_2O_3$를 담체로 한 Pt계 촉매에서 NOx, soot의 동시 제거 반응과 촉매의 열충격에 대한 연구를 수행하였다. 실험은 NOx와 soot의 반응을 독립 또는 동시에 반응시킨 조건으로 수행하였으며 그 결과 담체의 종류 및 상에 따라서 서로 상이한 NOx 제거능력과 soot 산화력을 나타내었고, soot의 산화시작온도의 결정은 NOx 제거능력과 상관관계가 있었다. NOx, soot의 동시 반응 시에는 생성된 $NO_2$에 의하여 soot 산화시작온도가 저온으로 이동하였다. 또한 열충격에 대한 NOx 제거율은 Pt/$Al_2O_3$ 촉매가 Pt/$TiO_2$ 촉매에 비하여 효율저하가 적게 일어났으며 soot 산화력은 활성점인 Pt의 소결현상에 의하여 촉매에 관계없이 모두 감소하였다.

• 한국소음진동공학회논문집
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• 제14권10호
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• pp.1021-1028
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• 2004

Developed friction snubbers changes the shock or vibration into a heat energy by mechanical friction. Snubber is divided into friction snubbers and hydraulic snubbers according to the operation types. However, hydraulic snubber has a lot of problems caused by temperature, humidity, radioactivity, and viscosity of hydraulic fluid. In these respects, to solve these problems, not only do friction snubber supplement lacks of hydraulic snubber but has also simpler structure than hydraulic snubber. In this paper, friction snubber used sponge iron by friction material is experimentally compared with general friction snubber In this results, the experiment verifies friction function and produce the manufacture condition for the effective friction snubber development.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.860-863
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• 1994

Main sources of increased vibrations and air noise on ship are main and auxiliary engines and ship ducts. The various ways of transfer of vibration energy and air noise in passenger cabin of a vessel require, in general case, of various methods of attenuation. The transfer of vibration energy from engines through a support requires, alongside with shock-absorbers, availability active shock-absorbers. The transfer of vibration energy and hydrodynamic noise on ship ducts requires availability, alongside with flexible muffler, active mufflers. The availability of air noise from working equipment can require, along with absorbent covers, of space systems of active noise control. In the given article it is spoken about the unified approach to formation of the block-diagram of active noise and vibration control. The complex approach permits to receive additional efficiency in reduction of noise in passenger cabin of vessels.

• 자원ㆍ환경경제연구
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• 제12권2호
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• pp.327-346
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• 2003

본고는 에너지소비와 경제성장의 관계를 밝히는 데 목적을 둔다. 먼저 에너지 소비, 물가, 실질소득으로 구성된 모형이 안정적임을 확인한 후, 오차수정모형을 이용하여 단기에 있어서 에너지 소비와 소득이 상호 영향을 미쳐 쌍방적 인과관계가 존재함을 보인다. 이와 더불어 예측오차의 분산분해와 충격반응함수를 도입하여 경제성장이 에너지소비를 증가시키나, 에너지소비증가가 경제성장에 미치는 효과는 단기적일 뿐 아니라 물가에 비교적 오랫동안 영향을 미친다는 것을 밝힌다. 이러한 사실은 우리나라의 경우 경제성장으로 에너지 소비가 증가하나, 증가한 에너지 소비가 인플레 등을 통해 경제성장의 장애요인으로 작용할 수 있음을 의미한다.

• 대한토목학회논문집
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• 제31권5D호
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• pp.689-695
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• 2011

본 논문에서는 도로공간에서 전력 생성이 가능한 신재생 에너지 기술들 중에서 압전효과를 활용하는 방법에 대한 연구를 수행하였다. 도로공간을 주행하는 수많은 차량을 이용하여 전력을 생성할 수 있는 신재생에너지 기술 연구의 일환으로, 외부의 충격하중을 전기에너지로 바꾸어 주는 압전효과를 이용하여 도로공간에 적용가능한 압전발전기를 개발하기 위한 기초연구를 수행하였다. 압전세라믹을 이용한 압전발전 수확기를 개발하기 위한 충격하중에 따른 특성 실험을 하였다. 압전발전기 형상 개발을 위해 충격하중 전달 방법, 충격흡수에 따른 압전세라믹의 발전 특성, 충격하중의 종류에 따른 압전 발전 수확기의 전압 발전 특성을 비교분석 하였다.

• 한국지열·수열에너지학회논문집
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• 제18권3호
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• pp.7-18
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• 2022

Secondary batteries used in electric vehicles have a potential risk of ignition and explosion. Various safety measures are being taken to prevent these risks. A numerical study was performed using a computational fluid dynamics code on the cases where pressure relief vents that can reduce the blast overpressures of batteries were installed in the through-compression test room, short-circuit drop test room, combustion test room, and immersion test room in facilities rleated to battery used in electric vehicles. This study was conducted using the weight of TNT equivalent to the energy release from the battery, where the the thermal runaway energy was set to 324,000 kJ for the capacity of the lithium-ion battery was 90 kWh and the state of charge (SOC) of the battery of 100%. The explosion energy of TNT (△H_TNT) generally has a range of 4,437 to 4,765 kJ/kg, and a value of 4,500 kJ/kg was thus used in this study. The dimensionless explosion efficiency coefficient was defined as 15% assuming the most unfavorable condition, and the TNT equivalent mass was calculated to be 11 kg. The internal explosion generated in a test room shows the very complex propagation behavior of blast waves. The shock wave generated after the explosion creates reflected shock waves on all inner surfaces. If the internally reflected shock waves are not effectively released to the outside, the overpressures inside are increased or maintained due to the continuous reflection and superposition from the inside for a long time. Blast simulations for internal explosion targeting four test rooms with pressure relief vents installed were herein conducted. It was found that that the maximum blast overpressure of 34.69 bar occurred on the rear wall of the immersion test room, and the smallest blast overpressure was calculated to be 3.58 bar on the side wall of the short-circuit drop test room.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.422-428
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• 1999

Aromatic hydrocarbons can be utilized as carbon and energy sources by some microorganisms at lower concentrations. However, they can also act as stresses to these organisms at higher concentrations. Pseudomonas sp. DJ-12 is capable of degrading 0.5 mM concentration of benzoate and 4-chlorobenzoate (4CBA). In this study, the exposure of Pseudomonas sp. DJ-12 to the pollutant stresses of benzoate and 4CBA at various concentrations was comparatively studied for its cellular responses, including survival tolerance, degradability of the aromatics, and morphological changes. Pseudomonas sp. DJ-12 utilized 0.5 to 1.0mM benzoate and 4CBA as carbon and energy sources for growth. However, the organism could not degrade the aromatics at concentrations of 3 mM or higher, resulting in reduced cell viability due to the destruction of the cell envelopes. Pseudomonas sp. DJ-12 cells produced stress-shock proteins such as DnaK and GroEL when treated with benzoate and 4CBA at concentrations of 0.5mM, or higher as sublethal dosage; Yet, there were differing responses between the cells treated with either benzoate or 4CBA. 4CBA affected the degradability of the cells more critically than benzoate. The DnaK and GroEL stress-shock proteins were produced either by 1mM benzoate with 5 min treatment or by higher concentrations after 10min. The proteins were also induced by 0.5mM 4CBA, however, it needed at least 20min treatment or longer. These results indicate that the chlorination of benzoate increased the recalcitrance of the pollutant aromatics and changed the conditions to lower concentrations and longer treatment times for the production of stress-shock proteins. of stress-shock proteins produced by the aromatics at sublethal concentrations functioned interactively between the aromatics for survival tolerance to lethal concentrations.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.360-363
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• 2006

Regester & Larkin(2005) suggest the issue and risk lifecycle analysis method in risk management, made up of the potential, emerging, current, crisis, and dormant stages. Investment on New & Renewable Energy is meaningful in effect ive risk management for diminishing or reducing the shock of a energy current, at the potential stage. In this study, we survey the risk of traditional fossil fuel projects and develop the risk analysis model for new & renewable energy projects specially geothermal energy resources and gas-hydrate resources.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.1057-1058
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• 2004