• 제어로봇시스템학회논문지
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• 제6권10호
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• pp.936-941
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• 2000

Advanced space transportation systems, such as the National Aerospace Plane or an Orbital Transfer Vehicle, have atmospheric maneuvering capabilities. For such vehicles the use of aeroassisted orbital transfer from a high Earth orbit to a low Earth orbit, with unpowered flight in the atmosphere, has the potential for significant fuel savings compared to exoatmospheric Hohmann transfer. However, to exploit the fuel savings that can be achieved by using the Earths atmosphere to reduce the vehicles energy, a guidance law is required, and it must be able to handle large unpredictable fluctuations in atmospheric density, on the order of ${\pm}$50% relative to the 1962 US Standard Atmosphere. In this paper aeroassisted orbital transfer is considered as a differential game, with Nature controlling the atmosphere density to yield a worst case (min-max fuel required) atmosphere, from which the guaranteed playable set boundary are achieved. Inside the playable set, it is guaranteed that the vehicle achieves the optimal atmospheric exit condition for the minimum fuel consumption regardless of the atmospheric density variations.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.213-219
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• 2010

MCU(Micro Controller Unit) used for the automobiles has been required for improving of the safety and high reliability. Also, the necessity of high performance MCU equipped with high fuel-efficiency has been risen according to increased requests of high fuel-efficiency and improving the occupants safety with the development of intelligent vehicles and future vehicles. The MPC5554 32-bit embedded controller, made by Freescale Semiconductor, specialized in the part of the power train provides the high reliability, fast interrupt process and real-time control. In This paper, the investigation on IPMSM using MPC5554 has been performed. Also SVPWM(Space Vector Pulse Width Modulation) is implemented to the servo system.

• 제어로봇시스템학회논문지
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• 제14권6호
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• pp.603-607
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• 2008

This paper proposes a fast acquisition method using INS velocity and multiple correlators for high speed vehicles. In order to reduce acquisition time in GPS receiver, the method utilizes inertial velocity information and multiple correlators. Search range of the Doppler frequency is reduced by using INS velocity and the number of cells at one search can be increased by using multiple correlators. By using both multiple correlators and the INS velocity in the acquisition, search space can be greatly reduced. Experimental results show that the method gives faster signal acquisition performance than the conventional method.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.214-215
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• 2013

교통망의 서비스 수준을 객관적으로 측정하는 주요한 기준은 통행시간과 지체시간이다. 본 논문에서는 주행차량 조사법을 이용하여 서비스 수준을 측정하도록 한다. 이를 통하여 시간당 교통량, 평균 통행 시간, 공간 평균 속도를 구할 수 있다. 또한 교통량의 밀도도 얻을 수 있다.

• ETRI Journal
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• 제36권6호
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• pp.968-978
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• 2014

Autonomous vehicle technology based on information technology and software will lead the automotive industry in the near future. Vehicle localization technology is a core expertise geared toward developing autonomous vehicles and will provide location information for control and decision. This paper proposes an effective vision-based localization technology to be applied to autonomous vehicles. In particular, the proposed technology makes use of numerical maps that are widely used in the field of geographic information systems and that have already been built in advance. Optimum vehicle ego-motion estimation and road marking feature extraction techniques are adopted and then combined by an extended Kalman filter and particle filter to make up the localization technology. The implementation results of this paper show remarkable results; namely, an 18 ms mean processing time and 10 cm location error. In addition, autonomous driving and parking are successfully completed with an unmanned vehicle within a $300m{\times}500m$ space.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(I)
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• pp.434-439
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• 2002

The researches on the direct drive system, which directly transfers axle load of the traction motor to wheels, have been developed as a next generation drive system in Japan and Europe. As a result of excluding couplings and gear units, the direct drive system has advantages on the bogie mount space to be smaller sized, lower noisy, more efficient and less weighted than the conventional drive system - indirect drive system. Since the simplification of the direct drive system design depends on the design of the traction motors, the researches on the direct drive system with focusing on the traction motors get started. The advantages/disadvantages of direct drive system, types, structures, cooling systems and interfaces of the traction motors are presented on this paper. Furthermore, the development of other countries on the electric equipments of the next generation railway vehicles are discussed and the necessity ＆ requirement for developing new concepts of traction motors are assured.

• 공학교육연구
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• 제17권5호
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• pp.17-22
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• 2014

Unmanned aerial vehicles (UAVs) that have been recently commercialized can largely be divided into fixed-wing aircraft and rotor aircraft by their styles and flight characteristics. Although the fixed-wing aircraft represents higher power efficiency, higher speed, longer flight distance and larger loading weight than the rotor aircraft, they have a disadvantage of requiring a space for take-off and landing. On the other hand, the rotor aircraft can implement vertical take-off and landing (VTOL) and represents various flight modes (hovering, steep bank turns and low-speed flights). But they require both precision take-off control and attitude control. In this study, we used a quad-tilt rotor UAV to combine advantages in both the fixed-wing aircraft and the rotor aircraft. The quad-tilt rotor (QTR) system was designed and constructed by adding a tilt device with a servo motor to a general quad-rotor vehicle.

• 전자통신동향분석
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• 제33권6호
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• pp.118-128
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• 2018

With the massive increase in bandwidth for wireless communications, free space optical (FSO) communication has attracted significant interest owing to its outstanding strengths over conventional radio frequency wireless communication such as a wide bandwidth, unlicensed spectrum, low power consumption, small size, electromagnetic interference immunity, long-range propagation, and improved security. In recent years, FSO technology has been studied intensively for use in terrestrial and underwater autonomous and unmanned mobile systems, a rapidly growing application area, including robots, drones, unmanned aerial vehicles, autonomous vehicles, unmanned trains, and unmanned submarines. In this report, we review the recent trends and key technologies for the mobile FSO system, and introduce our drone-based mobile FSO system, which is currently under development.

• 항공우주시스템공학회지
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• 제15권2호
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• pp.36-44
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• 2021

Unmanned aerial vehicles (UAVs) are increasingly needed as they can replace manned aircrafts in dangerous military missions. However, because of their low autonomy, current UAVs can execute missions only under continuous operator control. To overcome this limitation, higher autonomy levels of UAVs based on autonomous situational awareness is required. In this paper, we propose an autonomous situational awareness software consisting of situation awareness management, threat recognition, threat identification, and threat space analysis to detect dynamic situational change by external threats. We implemented the proposed software in real mission computer hardware and evaluated the performance of situational awareness toward dynamic radar threats in flight simulations.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2006년도 춘계학술발표대회 논문집
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• pp.65-66
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• 2006

The motor show is the most popular show in domestic exhibitions. It provides many interesting events and exhibition programs from small parts of the car to luxury sedans. It should be spatially designed for not only display programs but also various other programs such as concerts or events. And it needs to approach strategic and complex plans for unique stand design because of a great number of visitors' safety and accomodation, and competition with other companies. S motor is the company of middle standing, producing the most luxurious sedans and SUVs. I had to find a display and space composition way to harmonize with luxurious sedans and outdoor vehicles in a booth. The booth had to be distinctive and unique inspite of relatively small and handicaped area compared with other companies' booths. So I designed two major plans; ceiling structure covered whole booth space and office space for staff. These plans could get completely majesty and unique design for booth, events and other programs. And the structure of booth was minimalized for visitors' safety and accomodation in great event time.