• 항공우주시스템공학회지
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• 제10권3호
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• pp.32-38
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• 2016

This paper explains space-technology startup-business support programs. MSIP (Ministry of Science, ICT and Future Planning) and KARI (Korea Aerospace Research Institute) began running startup-business support programs from 2013 according to a "space-technology industrialization plan." In addition, MSIP and KARI have been running startup academies and STAR-Exploration for future entrepreneurs and startup companies since 2015. From these programs, five startup companies were established and they are generating sales. This paper shows the results of the programs, and the program cases of the startup and venture companies are analyzed for both domestic and international audiences. The future direction of startup-business support programs that are based on space technology is also discussed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.876-879
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• 1996

The vibration of an attractive magnetic levitation(Maglev) vehicle transportation system is caused by the irregularity of the guideway track and the performance of the suspensions of the Maglev system. It is essential for us to give attention to the secondary suspension of the vehicle system as it determines the ride quality. In order to improve the ride quality and running stability, active secondary suspensions have been developed and applied to the vibration problems. This paper analyzes the performance of the active secondary suspension which is applied to an attractive magnetic levitation vehicle system running on a rough track. The dynamics of the suspension system and the optimal control problems are studied. According to the transient and frequency response analyses to the track disturbance, the ride quality of an attractive Maglev vehicle has been improved by applying the designed LQR active controller, and it has been confirmed that this improvement was also influenced by the configuration of the system.

• Journal of Computing Science and Engineering
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• 제5권1호
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• pp.1-18
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• 2011

As the first step toward real-time multi-core computing, this paper presents a novel approach to bounding the worst-case performance for threads running on multi-core processors with shared L2 instruction caches. The idea of our approach is to compute the worst-case instruction access interferences between different threads based on the program control flow information of each thread, which can be statically analyzed. Our experiments indicate that the proposed approach can reasonably estimate the worst-case shared L2 instruction cache misses by considering the inter-thread instruction conflicts. Also, the worst-case execution time (WCET) of applications running on multi-core processors estimated by our approach is much better than the estimation by simply assuming all L2 instruction accesses are misses.

• 동력기계공학회지
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• 제14권1호
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• pp.27-33
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• 2010

We investigate some operation characteristics and energy efficiency of the BLDC motor system driven by different two types power conversion method depends on same battery source for applying to electrical motor propulsion system of a small ship. Also, we suggest an estimation manner of operating performances such as total running distance and operating speed of ships from basic discharge voltage characteristics of batteries. Through some experiments, direct power conversion was better than indirect method on the view point of energy efficiency and the voltage discharge characteristics could be used as important design factor for estimating operating performances of small ships driven by electrical motors.

• 수산해양기술연구
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• 제39권4호
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• pp.298-304
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• 2003

In this paper a free-form hull design program and performance prediction program for planing boat is introduced. This program enables the designer to do complex geometric hull shape design on a personal computer and accurately to predict power requirements for a given loading and velocity. For a free form design, Bezier curve model is adopted as a basic representation tool of curves and surfaces, and this program has versatile functions to do fairing jobs with a convenient graphical user interface. After creating a hull form the geometric data is provided in a manner compatible with a variety of analysis tools including 'Motion Analysis(by Zarnick)' for prediction of motion characteristics in regular waves, 'Running Attitude (by Savitsky)' for prediction of the running attitude and required power.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 춘계학술대회 논문집
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• pp.159-166
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• 1999

In this paper, running performance analyses of an articulated light rail vehicle are carried out using VAMPIRE software package. The stability analysis to determine the critical speed and the safety analysis such as derailment coefficients, lateral forces of wheels and reduction of wheel load are carried for the track conditions of straight, transition and curving range to the operating velocity of 40km/h. Also, ride quality is analyzed. As the results of analysis, the safety of light rail vehicle satisfied with the limit values and the ride quality for tare and full load condition was shown to the "not uncomfortable" level in ISO 2631-1 (1997) criteria.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.113-118
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• 2009

It is of utmost important that track loads at rail induced by running train was usually obtained for track performance evaluation. A reaction force of track was measured wheel loads and lateral force by strain gauges on the rail, and then it was obtained to derailment coefficient and variational ratio of wheel load from its relationship. In this study, a existing monitoring system methods with many manpower working were reviewed about measurements, process of testing, and how to obtain accurately measured data.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.761-764
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• 2013

n개의 원소로 이루어진 집합 S에서 r개의 원소를 선택하여 만들 수 있는 모든 조합을 평가하여 최적의 조합을 찾아내는 것은 많은 공학적 문제를 일반화하여 풀 수 있는 방법이다. 조합 전수조사 알고리즘은 경우의 수가 매우 크거나 각 조합을 평가하는데 많은 시간이 소요될 경우 알고리즘의 수행 속도가 급격히 저하되는 문제가 있다. 본 논문은 CUDA를 이용하여 각각의 조합을 GPU상의 스레드에서 병렬적으로 평가하는 기법을 제안한다. 실험 결과는 GPU상에서 동작하는 병렬적인 알고리즘이 CPU상에서 동작하는 순차적인 알고리즘에 비해 최대 약 900배의 성능 향상이 있음을 보인다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.557-562
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• 2004

The deterioration of a shunting locomotive was characterized for the lifetime assessment. The locomotive has been used for shunting works in steel making processes, and in this investigation, various types of technical evaluation methods for the locomotive parts were employed to assess the current deterioration status and to provide important clue for lifetime prediction. Unlike other rolling stocks in railway applications, the diesel shunting locomotive is composed of major components such as diesel engine, transmission, gear box, brake system, electronic devices, etc. In this paper, the analysis results of running performance assessment have been used to provide the critical information for the criteria of precision diagnosis assessment.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 공동학술발표회
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• pp.123-123
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• 2017