• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.05a
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• pp.233-263
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• 2003

연료전지차 필요성; 환경오염 측면-지구 온난화 가속,이산화탄소 총량 규제, 자동차 이산화탄소 배출량(배출량의 27% 차지), 고 효율 동력 시스템 필요. 개발 방향; 해외 연료전지 전문회사와 공동개발 추진, 본격 양산 대비한 자체기술 개발, 국내부품 전문업체 육성, 연료전지 실용화 Project 등 적극 참여, 주요 자동차 회사와 주기적 정보교환 회의 실시(중략)

• Defense and Technology
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• no.3 s.157
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• pp.32-41
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• 1992

최신예 전투기와 같은 첨단 항공기에서는 급가속 및 초음속 순항능력이 매우 중요한 구비조건 가운데 하나이다. 또 마하 2.3-5사이의 속도로 순항하는 오리엔트 익스프레스와 같은 차세대 민간항공기에서도 이러한 능력은 필수적이다. 일본에서는 21세기에 등장할 최첨단 항공기의 추진기관을 개발하는데 범국가적인 노력을 기울이고있으며 일부 성과는 이미 가시화되고 있다. 이 기술들이야말로 일본을 경제/군사 초강대국으로 밀어올리는 원동력이 아닌가 한다

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.383-387
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• 2011

The supercavitating rocket torpedo SHKVAL was analyzed in view of its system operation procedure and the structure and performance. 3 different propulsion systems installed in SHKVAL were 1st solid rocket booster for launch and acceleration, 2nd solid rocket booster for further acceleration, and Mg-rich Hydroreactive fuel rocket propulsion system for cruising. The gas generator used to help generate the supercavitation bubble was composed of a solid propellant gas generator and a hydroreactive fuel one. The structures and their performance were described based on as much knowledge as we have obtained from cumulative information and up-to-date analysis.

• Journal of Korean Society of Transportation
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• v.17 no.2
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• pp.69-79
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• 1999

This study evaluated the chance of driver's Psychophysiological load of occipital lobe at freeway merging area and compared with basic driving section. Ten persons of 8 men and 2 women were investigated at 3 basic section and 3 merging areas on the Youngdong freeway. It is found that driver's load in acceleration lane before merging is 2.21 times higher than the basic driving section. Further, driver's load for merging was maintained fur 4 seconds after merging. Particularly, driver's highest loading point in merging behavior was found to be 80m from the gore area.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.2
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• pp.41-46
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• 2015

The demand on low power and high performance system is soaring due to the extending of mobile and small electronic device market. The 3D die-stacking technology is widely studying for next generation integration technology due to its high density and low access time. We proposed the 3D die-stacked DRAM including a reconfigurable accelerator in a logic layer of DRAM. Also we discuss and suggest a cache-based local memory for a reconfigurable accelerator in a logic layer. The reconfigurable accelerator in logic layer of 3D die-stacked DRAM reduces the overhead of data management and transfer due to the characteristics of its location, so that can increase the performance highly. The proposed system archives 24.8 speedup in maximum.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.96-101
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• 1997

양자가속기를 외부 중성자 공급원으로 하여 미임계 운전을 가능하게 하고 토륨을 핵연료로 사용하므로 장주기 핵종과 핵무기 재료물질의 발생량을 현저히 줄일 수 있는 새로운 노형인 energy amplifier에 대한 연구가 CERN을 중심으로 활발히 진행되고 있다. 본 연구에서는 토륨주기에 대하여 고정 중성자속 조사에 의한 핵분열 및 방사붕괴에 관한 모델을 정립하여 다수의 연립선형 미분방정식으로 구성하여 Runge Kutta 5-6차 자동시간 간격 수치해법을 이용하여 계산하였다. 결과는 1014의 고정 중성자속에 대하여 충분한 U233의 생산이 평형상태에 도달하고 장주기 핵종도 우라늄 주기에 비하여 현저히 줄어듬을 보이므로 가속기를 이용한 토륨 핵연료 주기의 타당성을 확인하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.7
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• pp.777-787
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• 2012

The transient analysis for the output voltage of a piezoresistive microaccelerometer takes a relatively high computation time because at least two iterations are required to calculate the piezoresistive-structural coupled response at each time step. In this study, the high computational cost for calculating the transient output voltage is considerably reduced by an approach integrating the mode superposition method and the least square method. In the approach, data on static displacement and output voltage calculated by piezoresistive-structural coupled simulation for three acceleration inputs are used to develop a quadratic regression model, relating the output voltage to the displacement at a certain observation point. The transient output voltage is then approximated by a regression model using the displacement response cheaply calculated by the mode superposition method. A high-impact microaccelerometer subject to several types of acceleration inputs such as 100,000 G shock, sine, step, and square pulses are adopted as a numerical example to represent the efficiency and accuracy of the suggested approach.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.5
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• pp.465-473
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• 2010

As increase of height and slenderness of buildings, serviceability design criteria such as maximum lateral drift and wind-induced vibration level play an important role in structural design of high-rise buildings. Especially, wind-induced vibration is directly related to discomfort of occupants. However, no practical algorithm or design method is available for structural designers to control the acceleration level due to wind. This paper presented a control method for wind-induced vibration of high-rise buildings using the resizing algorithm. The level of vibration due to wind is calculated by well known estimation rules of ASCE 7-02, NBCC 95, SAA83, and Solari method. Based on the fact that the level of wind-induced vibration is inversely proportional to the magnitude of natural periods of buildings, in the design method, natural periods of a high-rise building are modified by redistribution of structural weight according to the resizing algorithm. The design method is applied to wind-induced vibration control design of real 42-story residential building and evaluated the efficiency and effectiveness.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.111-112
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• 2011

본 연구에서는 광전 용적맥파(photoelectric plethysmography, PPG)를 기반으로 이를 이용하여 혈관 탄성도를 측정 할 수 있는 시스템에 관하여 연구하였다. 광전 용적맥파는 광을 이용한 비 침습적 맥파 측정 방식으로 손가락 끝 부분에서 측정하고 혈액 내에 헤모글로빈의 빛에 대한 광 흡수도의 차이로 인해 나타나게 된다. 얻어진 신호를 2차 미분 하게 되면 가속도 맥파 (acceleration photoplethymogram, APG)를 얻을 수 있고 이는 혈관 탄성도의 추정에 응용가능하다. 본 연구에서는 혈관 탄성도를 측정하기 위한 방법으로 광전 용적맥파를 적용하여 가속도 맥파 측정기기를 설계하고, 이를 바탕으로 혈관 탄성도 추정에 적용 가능 여부를 연구하였다.

• 한국체육학회지인문사회과학편
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• v.55 no.2
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• pp.47-67
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• 2016

The purpose of this study was to understand barriers and problems associated with physical activity of older adults in a small town and to provide improvement plans based on socio-ecological model. This study employed three independent phases including survey, accelerometer study, and photovoice. Three phases were analyzed based on nesting design among diverse mixed method designs. Among 134 older participants, 73 older individuals reported that their physical activity per week was less than 150min in the first phase. Among the 73 older individuals, 40 older individuals participated in the second phase. In the second phase, 32 older individuals does not meet at least 150min of moderate-to-vigorous physical activity(MVPA) suggested by DHHS. Finally, 6 older adults participated in the third phase. Five major themes emerged including 1) lack of proper information and service regarding physical activity, 2)lack of support from people close to them, 3)some limits due to chronic disease, 4)lack of appropriate facility, and 5)lack of opportunity due to existing inactive lifestyle. Based on these five themes, this study attempted to provide the improvement plans with socio-ecological model.