• 한국자동차공학회논문집
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• 제11권2호
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• pp.148-156
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• 2003

Many car manufacturers have frequently adopted an aggressive inflator and a lower threshold speed for airbag deployment in order to meet an injury requirement for unbolted occupant at high speed crash test. Consequently, today's occupant safety restraint system has a weakness due to an airbag induced injury at low speed crash event. This paper proposes a new crash algorithm to improve the weakness by suppressing airbag deployment at low speed crash event in case of belted condition. The proposed algorithm consists of two major blocks-crash severity algorithm and deployment logic block. The first block decides crash severity with two levels by means of velocity and crash energy calculation from acceleration signal. The second block implemented by simple AND/OR logic combines the crash severity level and seat belt status information to generate firing commands for airbag and belt pretensioner. Furthermore, it can be extended to adopt additional sensor information from passenger presence detection sensor and safing sensor. A simulation using real crash data for a 1,800cc passenger vehicle has been conducted to verify the performance of proposed algorithm.

• 설비공학논문집
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• 제29권1호
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• pp.15-20
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• 2017

The summer climate is very hot and humid in Korea. The humidity is an important factor in determining thermal comfort. Recently, the research for dehumidification device development has been attempted to save energy that is required for the operation of the current dehumidifiers on the market. Existing dehumidification systems have disadvantages such as wasting energy to drive a compressor. Meanwhile, dehumidification systems with membranes can dehumidify humid air without increasing the dry bulb temperature so it doesn't have to consume cooling energy. In this paper, the cooling energy savings was studied when a dehumidification system was applied in a model building instead of a chiller. The sensible heat load was almost the same result, but the latent heat load was decreased by 38.9% and the total heat load was decreased by 8.5%. As a result, electric energy used to drive the compressor in a chiller was saved by applying a membrane air-conditioning system instead.

• 한국연소학회지
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• 제9권2호
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• pp.10-17
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• 2004

A two-dimensional direct numerical simulation is performed to investigate the flame structure of $CH_4/N_2-Air$ counterflow nonpremixed flame interacting with a single vortex. The detailed transport properties and a modified 16-step augmented reduced mechanism based on Miller and Bowman#s detailed reaction mechanism are adopted in this calculation. To quantify the strain on flame induced by a vortex, a scalar dissipation rate (SDR) is introduced. The results show that fuel-side and air-side vortex cause an unsteady extinction. In this case, the flame interacting with a vortex is extinguished at much larger SDR than steady flame. It is also found that air-side vortex extinguishes a flame more rapidly than fuel-side vortex. The unsteady effect induced by flame-vortex interaction does not lead to a transient OH overshoot of the maximum steady concentration observed in experiment, while $HO_2$ radical increases more than the maximum steady concentration with increasing SDR. In addition, it is seen that NO and $NO_2$ are not sensitive to the unsteady variation of SDR.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2015년도 추계학술대회
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• pp.175-178
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• 2015

본 논문은 국내외 해양사고 원인의 60-80%에 해당하는 인적과실을 예방하기 위하여 긴급상황에 대한 가상현실 선원 훈련 플랫폼을 제안한다. 제안된 훈련 플랫폼은 가상현실 기술을 통해 긴급 상황 내 절차 숙달을 위한 상호작용 방법과 가상 선박 환경 내에서 군중 에이전트를 제어하는 군중 제어 방법을 제공한다. 제안된 훈련 플랫폼의 상호작용 방법은 훈련 몰입도를 높이기 위하여 음성인식과 행동인식을 사용한다. 군중 제어는 사회적 특성을 반영한 에이전트의 행동모델을 적용하여 자연스러운 시뮬레이션을 제공한다. 제안된 훈련 플랫폼의 효율성을 실험하기 위해 선박 내 화재 상황에 대한 가상 훈련 시나리오를 standalone 훈련 플랫폼으로써 구현하였다.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제4권11호
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• pp.361-368
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• 2015

대공화기사격통제장치에서 유효사거리는 정지한 표적에 대해 충분한 파괴력을 가질 수 있도록 탄속이 음속 이상을 유지하는 거리로 정의되고 있다. 접근하는 표적은 탄과 표적 간 상대속도가 증가하므로 실질적인 교전 사거리는 위의 유효사거리보다 더욱 연장된다. 그러나 기존에 제시된 TOF 계산식은 유효사거리 내에서만 정확하고 유효사거리를 벗어나면 정확하지 못하다. 본 논문은 교전사거리를 보장할 수 있도록 유효사거리 내에서와 유효사거리 밖에서도 충분한 정확도를 가진 실시간 처리가 가능한 탄자비행시간 계산 기법을 제시한다. 시뮬레이션을 통해 30미리 대공 탄에 대한 본 논문의 유용성을 보인다.

• 한국안전학회지
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• 제26권1호
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• pp.21-26
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• 2011

Extinction and ignition characteristics of $CH_4$-air counterflow diffusion flame were numerically investigated using a Flame-Controlling Method(FCM). A skeletal reaction mechanism, which adopts 17 species and 58 reactions, was used in the simulation. The extinction and ignition conditions of the $CH_4$-air diffusion flames were investigated with varying the global strain rate. Upper and middle branches of S-curve for the peak temperature in the inverse of the global strain rate space were obtained with the FCM. The structures of diffusion flames in the upper and middle branches of S-curve were compared. It was found that the global strain rate was not correlated with the local strain rate well in the low global strain rate region. It is expected that the FCM is very useful to obtaining the extinction and ignition condition of diffusion flame, such as fires.

• 한국위성정보통신학회논문지
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• 제9권4호
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• pp.26-31
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• 2014

본 논문은 컬러 영상에서 색상과 움직임 정보를 이용하여 후보영역을 특정하고 연기의 특성들을 추출하여 신경망을 사용한 검출의 성능을 분석하여 제시한다. 기존 연기 검출 알고리즘에서는 연기의 움직임, 색상을 분석하여 후보영역으로 특정하고 그 영역 안에서 연기의 여러 특성을 분석 하는 방법을 이용한다. 하지만 대부분 처음 발생하는 연기의 색상조건을 고려하지 않았기 때문에 조기 검출에는 적절하지 못하다. 본 논문은 연기의 색상과 움직임의 특성을 분석하여 그에 알맞은 방법을 적용하여 후보영역을 폭넓게 결정하고 그 영역 내에서 연기의 확산과 투명성을 인공신경망에 적용시킴으로써 나오는 성능을 분석하였다. 모의실험 결과는 91.31%의 검출율과, 2.62%의 오검출율 성능을 확인할 수 있었다.

• 한국안전학회지
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• 제19권1호
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• pp.124-130
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• 2004

수치법을 검증하고 번형률과 연료농도가 무중력 확산화염 구조에 미치는 영향을 파악하기 위해, 무중력에서의 비예혼합 메탄-공기 대향류 화염의 구조를 FDS의 축대칭 모사로 조사하였다. 연료 중의 메탄 몰분율 $X_m$=20, 50, 80%와 각각의 몰분율에서 변형률 $a_g$=20, 50, $90s^{-1}$의 계산결과를 1차원 화염코드인 OPPDIF의 결과와 비교하였다. 축대칭 모사로 계산한 온도와 축방향 유속의 분포가 1차원 모사 결과와 잘 일치하였다. 화염의 두께와 위치, 정체점을 잘 예측함으로써 FDS를 넓은 범위의 변형률과 연료농도의 대향류 화염에 적응할 수 있음을 확인하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.1135-1138
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• 2003

The transformer is major equipment in power receiving and substation facilities. Necessary conditions required for the transformer are compactness, lightness, high reliability, economic advantages, and easy maintenance. The pole-mount transformer installed in distribution system is acting direct role in supply of electric power and it is electric power device should drive for long term. Most of modem transformer are oil-filled transformer and accident is happening considerable. The mold transformers have been widely used in underground substations in large building and have some advantages in comparison to oil-transformer, that is low fire risk, excellent environmental compatibility, compact size and high reliability. In addition, the application of mold transformer for outdoor is possible due to development of epoxy resin. The mold transformer generally has cooling duct between low voltage coil and high voltage coil. A mold transformer made by one body molding method has been developed for small size and low loss. One body molding transformer needs some cooling method because heat radiation between each winding is difficult. In this paper, The thermal analysis of pole mount mold transformer with one body molding by duct condition is investigated and the test result of temperature rise is compared with simulation data.

• Design & Manufacturing
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• 제15권3호
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• pp.50-55
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• 2021

Solar power generation, which is one of the methods of using solar energy, has a high possibility of practical implementation compared to other renewable energy power generation, and it has the characteristic that it can generate as much power as needed in necessary places. In addition, maintenance is easy, unmanned operation is possible, and power management can be performed more efficiently if operated in a hybrid method with existing electric energy. Therefore, in this study, numerical analysis using a computer program was performed to analyze the efficient operation and performance improvement of solar energy of the rotating condensing type solar LED street lamp. As a result, the two-axis tracking type could obtain 15.23 % more electricity per year than the fixed type, and additional auxiliary power generation was required for the fixed type by 19 % per year than the tracking type. As a result of computational fluid dynamics(CFD) simulation for PV module surface temperature prediction, the The surface temperature of the Photovoltaics(PV) module incident surface was predicted to be about 10℃ higher than that of the fixed type.