• Proceedings of the KSME Conference
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• 2000.04a
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• pp.684-689
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• 2000

In this paper, the equations of motion about vehicle, powertrain and brake system were derived. The vehicle has eight degrees of freedom with nonlinear tire model and the powertrain has two degrees of freedom containing engine, torque converter and four speed automatic transmission. The brake system has two states about front and rear brake line pressures. The transient tire model with first order time lag is also subjoined for low speed or stop-and-go simulation. The modeling was derived considering two points - the fidelity and the simplicity. The simulation using this model is similar with real vehicle dynamic behavior and the model is made as simple as possible far fast simulation. It is validated that the derived vehicle model can be applicable to the real time simulation.

• Journal of Power System Engineering
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• v.9 no.4
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• pp.168-174
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• 2005

A coreless electronic transformer is proposed. Conventional iron cored transformer is heavy and bulky and it has substantial amount of no load loss. On the other hand, electronic transformer can be made of negligible no load loss and is small size and lightweight. It consists of rectifier and PWM inverter. Electronic transformer is easily modeled to conventional Buck converter; therefore, output voltage is controlled by duty ratio. It is thought to be suitable for applications where the operation duty is low. In this paper, a novel coreless transformer is proposed, then it's detailed analysis, simulative and experimental results are presented

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.1
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• pp.63-74
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• 1996

Automatic transmission for heavy duty vehicles is a part of the power pack which includes steering and braking systems. This transmission in different from the one for passenger car. Therefore, in order to understand the trend of the important design parameters, maneuverability, acceleration performance and maximum speed, we need to analyze the total performance characteristics of the power transmission systems. In this study, modeling of the automatic transmission in heavy duty vehicle is carried out and the performance analysis method is presented. Results can be used for performance estimation data in the analysis for several combination method which determines the optimal parameters on the basis of penalty functions and weightings. And the estimation method of the important performance parameters such as engine inertia or power loss of engine by experiments is presented.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1995.05a
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• pp.117-122
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• 1995

원자력의 이용 분야 확대를 위하여 선박용 소형 동력로를 설계하였다. 본 연구에서는 다음의 제한 조건 및 설계 조건을 설정하여 핵적 개념 설계를 수행하였다. 노심의 부피는 국내 제작가능한 VLCC기종 유조선 기관실내에 배치 가능하도록 제한하였고, 선박의 정기 점검 기간에 맞춘 핵연료 재장전 주기 길이, 무붕산 노심 운전, 상용 가압경수로 보다 낮은 선출력과 출력 밀도, MUTSU호와 같은 1차 계통 열수력 조건, 등의 설계 조건을 설정하였다. 울진 3＆4의 핵연료 집합체의 길이만을 짧게 하여 사용하는 것에 대한 타당성 모색을 핵적 개념 설계 목표로 삼았다. 핵연료 집합체의 설계 및 반응단면적 생산은 CASMO-3 코트를, 노심 전체의 분석은 3차원 노달 코드인 KINS-3코트를 사용하였다. 개념 설계 결과, 노심 주기길이 690일을 달성할 수 있는 핵연료 집합체의 농축도와 갯수는 1.88%의 17개, 3.3%의 20개로 결정하였고, F$_{Q}$는 2.833이였고, 운전 상태에서의 감속재 온도 개수는 -24.8 pcm/$^{\circ}C$로 나타나서 한국형 원자로용 핵연료 집합체를 그대로 선박용 원자로에 사용 가능함을 볼 수 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.547-550
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• 2006

The power split hybrid power train is considered to be one of the most prospective configuration for the hybrid electric vehicle (HEV). Toyota Prius, representing this type of vehicle, showed outstanding performances in fuel efficiency, emission reduction and acceleration. The excellence is largely due to the fact that it utilizes almost all operation modes of HEV. Those modes include ZEV (Zero Emission Vehicle) driving, idle stop, fuel cut-off, power assist, active charging, regenerative braking and so forth. In this paper, a few of the mode operations were simulated using AVL Cruise. Also, control logics to operate the powertrain in each mode were developed. The states of powertrain components were displayed and analyzed. By controlling the three components (engine, motor and generator), it was possible to run the powertrain in several hybrid operation modes.

• Aerospace Engineering and Technology
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• v.12 no.1
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• pp.1-9
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• 2013

In order to increase endurance flight efficiency of long endurance electric powered UAV with solar cell, the light weight airframe design techniques are important. In this paper, the design of the main wing of electric powered UAV manufactured using Mylar film and fiber reinforced composite was conducted in order to achieve weight reduction and structural integrity of the structure. The shape of spar and size were determined using beam theory analysis. The finite element analysis of the wing was performed under various load condition derived from flight environment of EAV-2H. Finally, the static strength test of the main wing was conducted to verify structural integrity. It was found that the developed main wing weigh less than 42% than the previous EAV-2 and the main wing passed static strength test under ultimate load.

• Korean Journal of Medicinal Crop Science
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• v.13 no.6
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• pp.287-292
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• 2005

To investigate the effects of heat conservation materials on freeze damage and weed occurrence during overwintering in Saururus chinensis, Temperature difference was $6.9^{\circ}C$ in chaff, and was lower than those ranged from 9.7 to $14.4^{\circ}C$ in other materials. Heat conservation index, calculated from average temperatures below $-10^{\circ}C$ of earth's surface during the winter, was higher $1.7^{\circ}C\;and\;1.5^{\circ}C$ in chaff and lagging, respectively than in straw. Preservation of water is greater $9.6{\sim}26.1%$ in covering than in open field, and it increased in the order of lagging > chaff > straw among heat conservation materials. The survival rate of rhizome was increased in the order of 99% in lagging > 75% in chaff > 58% in straw, 32% in open field after overwintering, budbreak began fast, and the numbers of total budbreak per unit area were greater 22 times in lagging than 35.0 units in open field. Weeds occurrence was decreased in covering, i.e., $12.0{\sim}33.2\;units/m^2,\;7.3{\sim}10.7\;kg/10a$ of dry weight, and $5.6{\sim}6.4\;hours/10a$ of labor input compared with $157.2\;units/m^2,\;28.9\;kg/10a$ of dry weight, and 65.7 hours/10a of labor input in open field. Growth of top part was better in covering than in open field, and the number of tillers per unit area showed $347{\sim}396$ compared with 293 in open field. Marketable yields of dried stem and leaves and rhizome were higher $69{\sim}87%\;and\;58{\sim}88%$, respectively in covering than in open field, and among heat conservation materials, those were highest in lagging.

• Proceedings of the Costume Culture Conference
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• 2004.04a
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• pp.53-55
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• 2004

우리나라 니트 산업은 노동력, 자본, 범용 적인 차용기술, 원자재 등의 생산요소에서 원가절감을 통한 경쟁력의 이점을 추구하던 시기는 이미 지나 최근에는 중국의 중저가품 위주의 니트 제품들이 대량 유입되는 추세를 보이고 있다. 생산현장의 인력부족과 인건비 상승, 고유 기술 개발 미흡, 국제 원자재 의존성 등의 이유로 이미 대 선진국 수출에서 비가격 부문의 경쟁력을 상실한 국내 니트 업계는 선진국들의 니트 제품과의 가격 경쟁력까지 상실해 가고 있는 것이 현실이다. (중략)

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.07a
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• pp.175-180
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• 2003

벼 재배기술은 이앙재배 위주로 발전하여 왔으나 산업화로 인한 농업인구 감소와 이에 따른 노동력 부족, 노령화 및 임금상승으로 재배노력 절감을 위한 생력 기계화재배기술개발의 필요성이 증가하고 있다. 파종할 부분만을 경운하면서 볍씨를 파종ㆍ시비하고 배수구작업을 동시에 할 수 있어 노력 및 비용을 크게 절감할 수 있으며 무경운 포장에서 작업하므로 비가 온 다음날이면 파종작업을 할 수 있으므로 잦은 강우시 적기파종시기를 놓칠 수 있는 기존의 건답직파기술을 보완할 수 있는 장점이 있는 건답직파기계기술을 연구한 바 있다(박석호, 2002). (중략)

• The Safety technology
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• no.195
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• pp.24-25
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• 2014

고급 인쇄용지를 전문적으로 생산하고 있는 한솔아트원제지(주) 신탄진 공장. 이곳은 오산공장과 더불어 한솔아트원제(주)의 성장 동력을 제공하고 있다. 특히 신탄진공장은 연간 30만 톤에 달하는 생산능력을 보유하면서 제지업계에서는 입지를 확고히 굳히고 있다. 여기에 더해 이곳은 지역사회에서 무재해 안전사업장으로도 높은 명성을 얻고 있다. 이곳 관계자들은 이런 명성을 얻기까지 핵심적인 역할을 수행한 이를 꼽으라면 단언 한사람을 지목한다. 바로 오늘의 주인공인 현영대 과장이다. 왜 그가 사업장을 넘어 지역사회에서도 안전명인으로 불리는지 만나봤다.