• 제어로봇시스템학회논문지
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• 제13권3호
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• pp.273-278
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• 2007

In this paper, a performance comparison between CLOS(Command to Line-of-Sight) guidance law and PN(Proportional Navigation) guidance law is made, based on a short range surface-to-air missile simulation program called KNUCLOS. This simulation program has a full nonlinear aerodynamic missile model, a tracker model for missile and target, and target model. According to the simulation results, the PN guidance law has a better performance than CLOS guidance law under various target speed.

• 대한임베디드공학회논문지
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• 제10권2호
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• pp.57-64
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• 2015

In this paper, we propose structures and power spectral densities of UWB radar transmitters of Short Range Automobile. While the conventional transmitters did not consider interferences from self and other automobiles, the proposed method of this paper can minimize interferences. First, we compare a structure of the proposed method with pulse train and pulse compression method. Then, by using mathematical analysis and computer simulations, we show that the proposed method is superior to others. Also we can set proper parameters in UWB radar's transmitter through the numerical method of mathematical results.

• 전기학회논문지
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• 제61권11호
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• pp.1682-1688
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• 2012

This paper introduces a GP(Genetic Programming) based robust technique for temperature compensation in short-range prediction. Development of an efficient MOS(Model Output Statistics) is necessary to correct systematic errors of the model, because forecast models do not reliably determine weather conditions. Most of MOS use a linear regression to compensate a prediction model, therefore it is hard to manage an irregular nature of prediction. In order to solve the problem, a nonlinear and symbolic regression method using GP is suggested. The purpose of this study is to evaluate the accuracy of the estimation by a GP based nonlinear MOS for 3 days temperatures in Korean regions. This method is then compared to the UM model and has shown superior results. The training period of 2007-2009 summer is used, and the data of 2010 summer is adopted for verification.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.37-38
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• 2010

For MHz-class high frequency inverter in wireless power transfer applications, the voltage/current surges can be occurred in power stage when driving on the inverter. And also, the high-frequency oscillations can be produced at a high switching frequency due to the parasitic elements. The voltage and current stresses of the switching devices lead to the switching losses. The efficiency of the high frequency inverter will be reduced. And the inverter circuit with the sudden voltage and current fluctuations also generates the noise such as the EMI. Zero voltage, zero current switching technique can be used to reduce the switching loss and the noise. The high power density and high efficiency can be obtained. In this paper, the high-frequency inverter for short-range wireless power transfer applications was discussed. The feasible inverter circuit is analyzed in the circuit operating characteristics and the results are verified by the simulation.

• 디지털산업정보학회논문지
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• 제8권4호
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• pp.135-142
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• 2012

DSRC system is a communication system that consists of road side equipment and on board equipment to provide services of communication technology for intelligent transportation systems. In this paper, we carry out a short-range dedicated high-speed wireless communications via DSRC system based on board equipment that is installed in the vehicle and road side equipment through wireless channels of communication. on board equipment is system that have a memory which initialization information is stored, it loads physical layer and MAC layer, LLC layer, L7 layer in turn. In the upper, it should analyze the various commands that are sent from roadside base stations, and carry out the operation which is in accordance with the command. and also it designs the structure of protocol stack which is TRM Layer loaded that is to initialize on L7 layer and MAC layer and efficiently designs operation between on board equipment and the road side equipment.

• Journal of Welding and Joining
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• 제17권1호
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• pp.116-123
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• 1999

The $CO_2$ welding with 100% $CO_2$ shielding gas is commonly used because of its cost and efficiency. Arc phenomena of the $CO_2$ welding is influenced by various factors such as chemical compositions of welding wire, shielding gas, welding condition and welding power source etc. In this study, arc phenomena is investigated by using two type of FCW(titania type, semi-metal type). Then, the welding quality and optimum welding condition can be selected. From this study, the following results were obtained; 1) In low current range(140A), FCW up to welding voltage(22V) resulted in a typical short circuit transfer. 2) In high current range(320A), the arc stability in titania FCW of a typical globular transfer is better than that of semi-metal FCW.

• 한국재료학회지
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• 제24권3호
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• pp.135-139
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• 2014

To obtain the transistor with ambipolar transfer characteristics, IGZO/SiOC thin film transistor was prepared on SiOC with various polarities as a gate insulator. The interface between a channel and insulator showed the Ohmic and Schottky contacts in the bias field of -5V ~ +5V. These contact characteristics depended on the polarities of SiOC gate insulators. The transfer characteristics of TFTs were observed the Ohmic contact on SiOC with polarity, but Schottky contact on SiOC with low polarity. The IGZO/SiOC thin film transistor with a Schottky contact in a short range bias electric field exhibited ambipolar transfer characteristics, but that with Ohmic contact in a short range electric field showed unipolar characteristics by the trapping phenomenon due to the trapped ionized defect formation.

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2000년도 추계종합학술대회논문집
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• pp.41-44
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• 2000

본 논문에서는 동아대학교 RRC에서 개발한 게이트 자동화 시스템에 적용된 DSRC(Dedicated Short Range Communication) 시스템을 항만 내 야드 자동화에서도 이용하기 위해 이동 수송 차량에 장착되는 OBE(On-Board Equipment)와 야드에 설치되는 RSE(Road Side Equipment)간의 통신 소프트웨어 알고리즘을 제안하였다. 컨테이너 야드와 하역 시스템의 자동화를 구현하기 위해 OBE와 RSE간을 DSRC 방식으로 통신할 때 통신 대상에 따른 송수신 정보의 분류, 통신 대상의 분류 및 특성을 분석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2386-2388
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• 2005

As anti-crash and pre-crash systems in vehicles become more extensively used, the need for high performance short-range radars is playing an increasing role. This paper presents the design of a micromachined, ultra-wideband beamformer centered at 24 GHz for automotive short-range radar systems. This beamformer is a Butler matrix designed using ultra-wideband transmission-line couplers, which consist of a multilayered structure that exhibits wider bandwidth compared to conventional microstrip branch-line couplers. The circuit has been designed on a quartz substrate, and to achieve the desired coupling, lines suspended on BCB layers located at specific parts of the circuit were used, achieving a three metal layered structure in form of wide microstrips, that give low loss and a wideband response. In this paper the design and fabrication procedure of the proposed beamformer are fully described.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.555-558
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• 2006

블루투스는 전자기기 사이의 연결성을 위한 근거리 무선통신 기술의 표준이다. 본 논문은 블루투스 시스템에서 동일채널간섭의 영향을 분석하였고 수신된 비트의 BER과 SIR을 기반으로 성능을 평가하였다. 다양한 채널상태를 나타내기 위하여 Eb/No와 SIR 값에 따라서 블루투스 시스템의 성능을 분석하여 결과 그래프에 나타내었다.