• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.1
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• pp.33-40
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• 2022

With the recent increase in the development of military drones, they are adopted and used as the combat system of battalion level or higher. However, it is difficult to use drones that can be used in battles below the platoon level due to the current conditions for the formation of units in the Korean military. In this paper, therefore, we developed a program drones equipped with a thermal imaging camera and LiDAR sensor for reconnaissance and exploration that can be applied in battles below the platoon level. Using these drones, we studied the possibility and feasibility of drones for small-scale combats that can find hidden enemies, search for an appropriate detour through image processing and conduct reconnaissance and search for battlefields, hiding and cover-up through image processing. In addition to the purpose of using the proposed drone to search for an enemies lying in ambush in the battlefield, it can be used as a function to check the optimal movement path when a combat unit is moving, or as a function to check the optimal place for cover-up or hiding. In particular, it is possible to check another route other than the route recommended by the program because the features of the terrain can be checked from various viewpoints through 3D modeling. We verified the possiblity of flying by designing and assembling in a form of adding LiDAR and thermal imaging camera module to a drone assembled based on racing drone parts, which are open source hardware, and developed autonomous flight and search functions which can be used even by non-professional drone operators based on open source software, and then installed them to verify their feasibility.

• Journal of Trauma and Injury
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• v.32 no.3
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• pp.168-171
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• 2019

The treatment outcome remains poor of severe facial injuries because of the high risk of compromised airway or massive bleeding. We experienced two successful treatment cases of severe facial injury by the chainsaw. A 52-year-male had his face injured by the chainsaw during his work. He was transferred to the Level I trauma center using the Doctor-Helicopter. During his flight, bleeding control was tried and the information was given to the trauma surgeons before his arrival. His consciousness was alert and the vital signs were stable. The crushing wound, mandible open fracture, deep laceration of tongue, lip, neck and arterial bleeding were noted around his mandible. Nasotracheal intubation was performed under the bronchoscope-guided. Emergency operation (open reduction & internal fixation, primary repair with neurorrhaphy) was performed. At 30 hospital days, he was discharged with facial palsy on left mandibular area. A 30-year-male had his face injured by the chainsaw. He was transferred to our Level I trauma center from the local hospital. The deep-mutiple lacerations on right upper eyelid and forehead with the bony exposure were noted. The vital signs were stable and emergency operation was performed. He was discharged at 20 hospital days. Bone loss or tissue loss were not devastating than we expected even though the injury was occurred by the chainsaw. Aggressive treatment including airway manipulation or bleeding control and maximal opportunity of therapy are absolutely needed.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.135-140
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• 2000

Matsucoccus thunbergianae is a major insect pest of Pinus thunbergiana in southern Korean peninsula. To study the flight behavior of M. thunbergianae males responding to the synthetic pheromone, five sticky traps were placed on a bamboo pole at various heights, between 0.1m and 2.0m above ground. A bait impregnated with the synthetic pheromone was placed at 0.1m, 1.0m or 2.0m above ground and the number of male catches on each trap was counted. In an open area, numbers of males caught per trap were not different between heights when the bait was placed at 2m or 1m above ground ; when the bait was placed at 0.1m height, male flight was aggregated near the ground. In a forest with low crown closure, trap catches on five traps on the same bamboo pole were not different one another when the bait was placed at 2m height, but most males were flying near the bait when it was placed at 1m height. In a dense pine forest, most males were flying around the bait regardless of the bait position. In all three places, most males were caught on the trap near the ground when the baits were placed 0.1m above ground. Thus, for monitoring the frontal zone of infestation of the scale, placing the pheromone trap near the ground was considered the most efficient. When the males perceived pheromone, they tended to fly in the air with low wind speed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.160-164
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• 2007

In the steel industry, there is a need to produce large forged parts for the automobile industries, the flight and shipping industries ad military industries. In the steel-industry application, a cogging technique for cast ingots is required, because the major parts are needed as one large body in order to obtain higher quality. Therefore, cogging process is the primary step in manufacturing of practically large open-die forging. In the cogging process, internal voids have to be eliminated as defects, The present work is concerned with the elimination of the internal voids in large ingots so as obtain sound products. In this study, hot compression tests were carried out to obtain the flow stress of cast microstructure at different temperature and strain rates. The FEM analysis are performed to investigate the overlap defect of cast ingots during cogging stage. The measure flow stress data were used to simulate the cogging process of cast ingot using the practical material properties. Also the analysis of void closure are performed by using the $DEFORM^{TM}$-3D. The calculated results of void closure behavior are compared with the measured results before and after cogging, which are scanned by the X-ray scanner. From this result, the criteria for deformation amounts effect on the void closure can be investigated by the comparison of practical experiment and numerical analysis.

• Journal of Advanced Navigation Technology
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• v.24 no.3
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• pp.173-183
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• 2020

This research focused on such a passenger sample that used to fly between Incheon int'l airport(ICN) and Dubai int'l airport(DXB) using either a national carrier or gulf carriers because the route between ICN and DXB is one of the international air routes with the toughest competition under the global pressure of open air transport market. Based on the results from the empirical research, this paper proposed a competitive advantage which a national carrier must have to cope with global competition under the open sky policies and implications for sustainable strategies of them. National carrier passengers perceived product benefits had a significant positive effect on price reliability in spite of lower price competitiveness. Following the empirical analysis results, it was proven a national carrier should try to improve product benefit sought by passengers to maintain sustainable competitive advantage in the market against foreign airlines.

• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.269-276
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• 2012

The purpose of This study's aim is to examine the difference in the changes of body segment movement, variables for ball quality, and carry at golf driver swing according to the ball quality using comparative analysis. Regarding the impact variables according to the ball quality using the track man and carry, club speed was the fastest at draw shot, ball speed was the fastest at straight shot, and smash factor was the lowest at draw shot. About the vertical launch angle, the fade shot showed the highest launch angle while the max height of the ground and ball was the highest at fade shot. And carry was the longest at draw shot. For the flight time, it was the longest at draw shot. The landing angle was the largest at fade shot. About the club head position change and trajectory, at the overall event point, the fade shot drew a more outer trajectory at the point of the follow through(E6) than the straight or draw shot. Regarding the angular speed of shoulder rotation, at the overall event point, the fade shot showed the greatest angular speed change in the follow through(E6). Also, about the angular speed of pelvic rotation, at the overall event point, the draw shot showed the greatest angular speed change at the point of down swing(E4). Concerning the stance angle change, both straight and fade shots were open as the concept of open stance whereas the draw shot was close as that of close stance. Regarding the previous study, the most important factor of deciding Ball Quality is the club face angle's open and close state at Impact. In short, the Ball Quality and carry were decided by this factor.

• Advances in aircraft and spacecraft science
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• v.4 no.2
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• pp.145-167
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• 2017

The presented paper gives an overview of several projects addressing the experimental characterization and control of the buffet phenomenon on 3D turbulent wings in transonic flow conditions. This aerodynamic instability induces strong wall pressure fluctuations and therefore limits flight domain. Consequently, to enlarge the latter but also to provide more flexibility during the design phase, it is interesting to try to delay the buffet onset. This paper summarizes the main investigations leading to the achievement of open and closed-loop buffet control and its experimental demonstration. Several wind tunnel tests campaigns, performed on a 3D half wing/fuselage body, enabled to characterize the buffet aerodynamic instability and to study the efficiency of innovative fluidic control devices designed and manufactured by ONERA. The analysis of the open-loop databases demonstrated the effects on the usual buffet characteristics, especially on the shock location and the separation areas on the wing suction side. Using these results, a closed-loop control methodology based on a quasi-steady approach was defined and several architectures were tested for various parameters such as the input signal, the objective function, the tuning of the feedback gain. All closed-loop methods were implemented on a dSPACE device able to estimate in real time the fluidic actuators command calculated mainly from the unsteady pressure sensors data. The efficiency of delaying the buffet onset or limiting its effects was demonstrated using the quasi-steady closed-loop approach and tested in both research and industrial wind tunnel environments.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.92-96
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• 2007

Microphone array beamforming method has been recognized as an important aeroacoustic research field and become a standard technique in localizing sound sources. This method also used in flight acoustic measurement, and especially, it is very useful when measure sounds inside the wind tunnel. In measuring sound which is inside the wind tunnel by traditional beamforming method, there are some errors caused by airstream. The speed and the propagation path of the sound changes as it travel through the airstream. This makes the error which the position of sound is changed a little bit to the down stream direction. In this paper, validation test has made about the correction equation for this wind effects of previous researches. And beamforming including shear layer correction was performed about a sound source in the anechoic open-jet windtunnel.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.970-973
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• 2017

기존 산업 및 게임분야에서 사용하던 M&S(Modeling and Simulation) 기술이 국방 분야로 확대되어 다양한 연구 개발이 진행되고 있다. 그러나 군사 선진국들에 비해 우리군은 시뮬레이션 표준 기술 구조가 부재하여 상호운용성과 재사용성이 다소 부재하다. 또한 시뮬레이션을 위한 모델링이 다소 현실감이 떨어지고, 역동적이지 못하다는 한계가 있다. 이에 본 논문에서는 재사용성과 상호운용성을 향상시키기 위해 DIS 표준구조에 맞추어 아키텍처를 구성하고, 3D MAX와 Open Flight 엔진을 활용하여 역동적이고 현실감 있는 모델링 제작하였다. 또 VR Vantage의 3D Viewer를 통해 제작된 모델링 오브젝트가 정상 구동되는지 확인하였다.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.590-595
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• 2001

VTree는 개발시간을 감소시키고 실시간 3차원 그래픽스 응용 프로그램의 성능을 향상시키는 객체지향 OpenGl기반 소프트웨어 개발 툴킷으로 비주얼 시뮬레이션과 가상현실 응용프로그램을 빠르게 구현하게 해주는 개발 환경을 제공한다. 이 논문에서는VTree 툴킷에서 제공해주는 다양한 특징들을 소개하고, 이 특징들을 이용하여 구현한 비행 시뮬레이션의 구현과정을 기술한다. 본 연구팀에서 구현한 시뮬레이션의 구현내용은 비행기의 수직 360도 회전비행, 수평 360도 회전비행, 여러 비행기의 교차비행 외에 몇 개의 동작들을 구현하였다. 몇 가지 비행 동작을 구현하는 과정에서 VTree 툴킷을 사용한 방법을 기술하며, 구현과정에서 발생된 몇 가지 문제점들과 향후 연구과제를 소개하는 것이 이 논문의 목적이다.