• Journal of Satellite, Information and Communications
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• v.12 no.1
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• pp.43-48
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• 2017

Recently, demands on civilian UAV (Unmanned Aerial Vehicle) has been increasing and appropriate communication system is required for the UAV. In this paper, the performance of the UAV communication system using commercial wireless mobile network is discussed. The main service area of the wireless mobile network is ground level however the flying range of the UAV is normally in high altitude. Because of this mismatch of service area the performance of the UAV communication system is degraded in high altitude. To compensate performance degradation of the UAV communications system in high altitude, adaptive array antenna is introduced which is able to overcome altitude limitation of the UAV communication system.

• International journal of advanced smart convergence
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• v.6 no.3
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• pp.38-44
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• 2017

Currently, wired gables have been installed or portable storage devices have been installed for data acquisition of flying drone. In this paper, we propose a technology to transmit data wirelessly by sensing information such as battery discharge value, acceleration, and temperature by attaching RF sensor to a drone. The purpose of this paper is to design and develop the monitoring technology of agriculture drone battery usage in real time using RF sensor. In this paper, we propose a monitoring system that can check real time data of battery changed value, temperature, and acceleration during pesticide control activity of agricultural drone.

• Journal of Communications and Networks
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• v.17 no.4
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• pp.384-393
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• 2015

This paper proposes an insect behavior-inspired routing algorithm for large-scale wireless mesh networks. The proposed algorithm is adapted from the behavior of an insect called Bombyx mori, a male silkmoth. Its unique behavior is its flying technique to find the source of pheromones. The algorithm consists of two steps: the shortest-path algorithm and the zigzag-path algorithm. First, the shortest-path algorithm is employed to transmit data. After half of the total hops, the zigzag-path algorithm, which is based on the movement of the male B. mori, is applied. In order to adapt the biological behavior to large-scale wireless mesh networks, we use a mesh topology for implementing the algorithm. Simulation results show that the total energy used and the decision time for routing of the proposed algorithm are improved under certain conditions.

• International Journal of Aeronautical and Space Sciences
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• v.6 no.2
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• pp.17-22
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• 2005

As one of validation tool for attitude determination system, we have used various constraints using priori information which is known through base vector set up. However these conventional constraints cannot guarantee validity in terms of final solutions such as Euler angle. So we suggest attitude boundary concept to verify the final attitude solution on the flying airplane, it is based on the combination of velocity based attitude estimation technique and ambiguity resolution. we can say it can check invalid solution effectively at just one epoch without repeatability test of resolved cycle ambiguity. In this paper we show that the suggested constraint can effectively reject incorrectly resolved cycle ambiguity the conventional constraints have missed.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.14 no.4
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• pp.74-86
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• 2006

As competition among airliners is getting sharper, promotion mix has been more important for new customers as well as old customers. In this research, how the systems for giving benefits for frequent flying customers are organized and the effects of the systems are analyzed. also, the effects of providing information by internet and issuing bonus card are investigated. As a research method, we inquired into questionnaire, and multi-regression test and ANOVA analysis are conducted. The customers who fly more frequent and have more desire to utilize milage cooperation system among airliners show more loyalty to the systems. Also, cooperation system among different industries is turned out to be effective from the marketing point of view. Also, the result of the test of internet-based system showed effective.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.163-170
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• 2005

In this work, we propose a new type of HDD Load/unload (L/UL) suspension featuring shape memory alloy (SMA). The mechanical and thermal properties of the SMA film with respect to the material phase states are experimentally estimated and the SMA film is carefully integrated to the suspension. In order to obtain the desirable dynamic characteristics of the suspension during L/UL process, the design parameters of the SMA film such as geometric properties are determined by considering the vibration modes of the suspension related to the L/UL performance. After analyzing the modal characteristics of the proposed suspension, L/UL performance is evaluated through L/UL simulation by observing the vibration motion and minimum flying height of the slider during L/UL process.

• Proceeding of EDISON Challenge
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• 2016.11a
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• pp.58-62
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• 2016

본 연구에서는 지면효과의 영향을 비행체의 형상에 따라 비교하기 위해 에어포일, 플랩을 장착한 에어포일 그리고 플라잉디스크를 EDISON_CFD를 통해 해석하고자 한다. 받음각 $0^{\circ}$, $5^{\circ}$, $10^{\circ}$에 대하여 마하수 0.18, 단위 길이 당 레이놀즈수 $3.78{\times}10^{-5}/m$의 유동조건에서 2차원 범용 소프트웨어인 KFLOW_EDISION_13의 S-A Turbulent Model을 이용하여 지면과의 높이를 형상 코드길이를 기준으로 0.25c, 0.5c, 1c, 3c로 변경하면서 해석을 수행하였다. 그 결과 세 형상 모두 일반적인 지면효과인 지면과 가까울수록 양력계수는 증가, 항력계수는 감소하여 양항비가 증가하는 경향을 보여주었다. 하지만 일부 예외적인 부분을 확인하여 분석을 실시하였다.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.566-570
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• 2016

본 연구에서는 플라잉 디스크를 이용하여 Pitching 운동 조건에서의 공력특성을 해석하였다. 본 해석에서 사용한 플라잉 디스크 모델은 프리원 151_140이며, 해석자로는 KFLOW_EDISON_2D_3DOF를 사용하였다. Pitching 운동이 있는 경우 받음각의 변화에 따른 공력특성을 비교 분석하였다. 기준 받음각의 변화에 따라 형상 아랫면과 뒷전 부근에 실속 와류가 다른 형태로 생겨 플라잉 디스크의 공력 특성에 영향을 준다는 것을 확인하였다. 또한, 기준 받음각이 증가 할수록 강한 실속 와류가 발생함을 알 수 있다.

• Advances in aircraft and spacecraft science
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• v.6 no.4
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• pp.283-296
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• 2019

The influence of different planform parameters on the aerodynamic performance of large-scale subsonic and transonic Blended Wing Body (BWB) aircraft have gained comprehensive research in the recent years, however, it is not the case for small-size low subsonic speed Unmanned Aerial Vehicles (UAVs). The present work numerically investigates aerodynamics governing four different trailing edge geometries characterizing BWB configurations in standard flight conditions at angles of attack from $-4^{\circ}$ to $22^{\circ}$ to provide generic information that can be essential for making well-informed decisions during BWB UAV conceptual design phase. Simulation results are discussed and comparatively analyzed with useful implications for formulation of proper mission profile specific to every BWB configuration.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.4
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• pp.154-163
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• 2020

The pilot's aeronautical decision-making during the flying greatly affects flight safety, and the importance of situational awareness has been greatly emphasized as a prerequisite for making the right decision. This is the reason why more research and interests are needed to help students entering the pilot training program develop excellent situational awareness from the initial stage of training. Situational awareness is closely related to long-term memory activities in human information processing, and pedagogy and cognitive psychology have emphasized the encoding techniques as an effective long-term memory method. This study was conducted to confirm whether pilot students' using the encoding techniques to learn flight education materials in the early stage of their training at domestic universities has a positive effect on improving their situational awareness.