• Aerospace Engineering and Technology
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• v.13 no.2
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• pp.1-6
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• 2014

Power system of the tilt-duct VTOL aerial robot has been developed. This paper focuses on the power train with small liquid-type engine for the R/C boat and presents the test results with design procedures. The hardware aspects of the power system include details about the hardware configurations for the interfaces with the vehicle. The ground test and tether test for measuring the thrust performance of vehicle and evaluating the endurance of power train carried out.

• Electronics and Telecommunications Trends
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• v.32 no.4
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• pp.78-88
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• 2017

무인기의 기술 발전에 따른 운송, 통신중계, 교통감시, 산불감시 진화, 재해 재난대처 등 무인기의 민간 및 공공 수요가 확대되고 있다. 무인기는 국가 공역으로의 운항이 요구되는데, 국가 공역으로의 안전한 진입을 위해서는 유인항공기 조종사에 의한 시각 감지 및 회피와 동일할 수준의 안전성을 제공하는 탐지 회피 능력과 함께 신뢰성 높은 무인기 제어용 통신링크 확보가 필수적으로 요구되고 있다. 따라서, 본고에서는 국외 기술 개발 및 표준화 동향을 바탕으로 국가 공역에서의 무인기의 안정적 진입을 위해 필요한 무인기 지상 제어용 통신 및 네트워크 기술에 대해 살펴보고자 한다.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1999-2004
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• 2004

Collision avoidance for the aircraft can be stated as a problem of maintaining a safe distance between aircrafts in conflict. Optimal collision avoidance problem seeks to minimize the given cost function while simultaneously satisfying the constraints. The cost function can be a function of time or input. This paper addresses the trajectory time-optimization problem for collision avoidance of the unmanned aerial vehicles. The problem is difficult to handle, because it is a two points boundary value problem with dynamic environment. Some simplifying algorithms are used for application in on-line operation. Although there are more complicated problems, by prediction of conflict time and some assumptions, we changed a dynamic environment problem into a static one.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.07a
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• pp.27-28
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• 2016

실시간 렌더링 시스템에서 시야를 변경하는 속도가 증가할수록 FPS(Frame Per Second)가 감소하는 문제가 발생한다. 이에 따라 시야 변경이 증가할수록 감소하는 FPS를 향상하기 위한 렌더링 최적화 기술이 요구되며, 본 논문에서는 동적 LOD(Level of Detail)와 컬링 기술을 적용하여 실시간 렌더링 과정에서 렌더링 데이터를 감소함으로써 저하되는 FPS를 증가시키기 위한 렌더링 최적화 기법과 HMD(Helmet Mounted Display)의 움직임에 따라 변경된 시야각을 적용한 OSG(Open Scene Graph) 기반 실시간 렌더링 시스템을 제시한다.

• Advances in aircraft and spacecraft science
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• v.3 no.4
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• pp.399-425
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• 2016

The dynamical requirements are obtained for airplanes to travel on inclined circular trajectories. Formulas are provided for determining the load factor, the bank angle, the lift coefficient and the thrust or power required for the motion. The dynamical properties of the airplane are taken into account, for both, airplanes with internal combustion engines and propellers, and airplanes with jet engines. A procedure is presented for the construction of tables from which the flyability of trajectories at a given angle of inclination can be read, together with the corresponding minimum and maximum radii allowed. Sample calculations are shown for the Cessna 182, a Silver Fox like unmanned aerial vehicle, and a F-16 jet airplane.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.13 no.2
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• pp.14-26
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• 2005

A tilt-rotor aircraft has various flight modes : helicopter, airplane, and conversion. Each of flight mode has unique and nonlinear flight characteristics. Therefore the gain schedules for whole flight envelope are required for effective flight performance. This paper proposes collective, flap, and nacelle angle scheduler for whole flight envelope of the Smart UAV(Unmanned Air Vehicle) based on CAMRAD(Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics) II analysis results. The scheduler designs are improved so that the pitch attitude angle of helicopter mode was minimized. The range of scheduler are reduced inside of engine performance limits. The conversion corridor and rotor governor are suggested also.

• Journal of computational fluids engineering
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• v.17 no.4
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• pp.56-68
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• 2012

Nowadays, Unmanned Combat Air Vehicle(UCAV) has become an important aircraft system for the national defense. For its efficiency and survivability, shape optimization of UCAV is an essential part of its design process. In this paper, shape optimization of UCAV was processed for aerodynamic performance improvement and Radar Cross Section(RCS) reduction using Multi Objective Genetic Algorithm(MOGA). Lift and induced drag, friction drag, RCS were calculated using panel method, boundary layer theory, Physical Optics(PO) approximation respectively. In particular, calculation applied Radar Absorbing Material(RAM) was performed for the additional RCS reduction. Results are indicated that shape optimization is performed well for improving aerodynamic performance, reducing RCS. Further study will be performed with higher fidelity tools and consider other design segments including structure.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.24 no.4
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• pp.6-11
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• 2016

There has been an increase in the number of researches on the segment for commercialization after developing avionics systems. In this paper, we have applied a commercial off-the-shelf(COTS) operating systems in an aircraft mission computer. We used UAV collision avoidance algorithms to compare the performance of COTS operating systems. The UAV collision avoidance algorithms were tested on different operating systems to compare the performances of the operating systems. The measured parameters are memory usage and processing time. We have verified that the UAV collision avoidance algorithms worked successfully and compared the performance of each operating system.

• Journal of Aerospace System Engineering
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• v.7 no.3
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• pp.65-69
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• 2013

Avionics system designed for the 200 kg-class tiltrotor UAV has been developed. Avionics system for the UAV is the reconstruct system and can be programmed automation controller. This paper focuses on the design aspects of the hardware and presents the ground and flight test results. The hardware aspects of the avionics system include details about the hardware configurations for the interfaces with the Digital Flight Control Computer, sensors and Line-replaceable unit modifications.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.148.1-148
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• 2001

The airship is starting to receive new highlights as a stable floating platform. A floating platform can serve as a telecommunication relay station or an environmental outpost. Much of these operations require unmanned autonomous operation on the airship. Due to difficulties in modelling and identifying the airship, controlling the airship is not an easy task. Different from the normal aircraft, the airship is affected by "added mass" and buoyancy. The added mass is the additional mass felt required to move the object in a fluid. As we are searching for a stable floating platform, controlling the airship to keep station is critical. We use a simple airship model with added mass for simulation. Classical controller is used to find acceptable airship performances.