• Korean Journal of Remote Sensing
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• v.39 no.5_2
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• pp.849-858
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• 2023

Investigating disaster sites such as earthquakes and landslides involves significant risks due to potential secondary disasters like facility collapse. In situations where direct access is challenging, there is a need to develop methods for safely acquiring high-precision 3D disaster information using light detection and ranging (LiDAR) equipped drone survey systems. In this study, the feasibility of using drone LiDAR in disaster scenarios was examined, focusing on the collapse accident at Jeongja Bridge in Bundang-gu, Seongnam City, in April 2023. High-density point clouds for the accident bridge were collected, and the bridge's 3D terrain information was reconstructed and compared to the measurement performance of 10 ground control points. The results showed horizontal and vertical root mean square error values of 0.032 m and 0.055 m, respectively. Additionally, when compared to a point cloud generated using ground LiDAR for the same target area, a vertical difference of approximately 0.08 m was observed, but overall shapes showed minimal discrepancies. Moreover, in terms of overall data acquisition and processing time, drone LiDAR was found to be more efficient than ground LiDAR. Therefore, the use of drone LiDAR in disaster sites with significant risks allows for safe and rapid onsite investigations.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.145-152
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• 2017

As a popularization of small UAS to have improved flight performance and easiness of controlling, the UAS industry is increased and also small UAS is to be a new threat for airspace security of national strategic infrastructure. Rising the new threat makes the negative side effect of small UAS operation. This phenomena brought to new R&D needs "defense system" for small UAS/UAV - called Anti-Drone. The paper addressed case study of defects, accidents and threats by small UAS/UAV as world wide level, and research and development trend of UAS defense system as each technical category - CONOP (Concept of Operation), identification/recognition method and control/supremacy techniques. As a result, this suggests the direction what and where drone defense system should be applied first and required for Korean society in the view of society system (regime) and a point of view for minimizing side effect as UAS popularization.

• Journal of Practical Engineering Education
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• v.9 no.1
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• pp.7-13
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• 2017

This study will provide a practical plan of engineering education through the study of major activities connected with the production of works to accomplish the graduation conditions by completing the comprehensive design subject and the result of the performance. The designed subject is to measure the minimum safety distance during driving using the obstacle detection function of the ultrasonic sensor and to perform the avoidance algorithm based on the measurement value of the acceleration gyro sensor. It is proposed an access surveillance system that minimizes the damage of drones, surrounding objects, and people, and improves air mobility. Experimental results show that the obstacles around the drone are detected by five ultrasonic sensors and the difference of output value is applied to each motor of the drone and obstacle avoidance is confirmed. In addition, the content and level of the data for measuring the achievement of learning achievement in the engineering education certification program were used and the results were confirmed to be consistent with the description of the engineering problem level required for the graduates of 4-year engineering college.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.12
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• pp.997-1004
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• 2020

A synchropter is a type of rotorcraft in which a pair of blades inclined with each other rotates in synchronization. Removing the tail rotor enables an efficient and compact configuration similar to a coaxial-rotor helicopter. This paper describes the design and flight test results of a small synchropter to examine the suitability of a drone system for the army. The synchropter in this paper is a small vehicle with a rotor diameter of 1.4m and a weight of 7kg and was assembled based on commercial parts to examine flight characteristics effectively. The flight control system adopted Pixhawk, which is designed based on an open-architecture. The model-based design technique is applied to develop the control law of the synchropter and a new firmware embedded on the Pixhawk. Through qualitative flight tests, we analyzed the flight characteristics. As a result of the analysis, we confirmed the possibility of application as a drone system of the synchropter.

• Convergence Security Journal
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• v.23 no.3
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• pp.65-71
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• 2023

The importance of combat drones has been highlighted through the recent outbreak of the Russia-Ukraine war. The combat drones play a significant role as a a game changer that alters the conventional wisdom of traditional warfare. Many pundits expect the role of combat swarm drones would be more crucial in the future warfare. In this regard, this paper aims to analyze the development of artificial intelligence-enabled combat swarm drones. To transform the human-operated swarm drones into fully autonomous weaponry system our suggestions are as follows. Developments of (1) AI algorithms for optimized swarm drone operations, (2) decentralized command and control system, (3) inter-drones' mission analysis and allocation technology, (4) enhanced drone communication security and (5) set up of ethical guideline for the autonomous system. Specifically, we suggest the development of AI algorithms for drone collision avoidance and moving target attacks. Also, in order to adjust rapidly changing military environment, decentralized command and control system and mission analysis allocation technology are necessary. Lastly, cutting-edging secure communication technology and concrete ethical guidelines are essential for future AI-enabled combat swarm drones.

• The Journal of Korean Institute of Information Technology
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• v.16 no.12
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• pp.49-56
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• 2018

As the era of the 4th industrial revolution comes, there is a growing interest in the use of UAVs. While various technologies are being developed using drones, controlling flight of drones is the most basic. Hovering control is essential in order to enable autonomous flight, especially during flight control of drones. In this paper, we design drones based on ATmega2560, Sonar, Optical Flow, and acceleration / gyro 6 axis sensor for drones hovering control, and developed horizontal control, altitude control, position tracking and fixed algorithm based on PID control. In this research, in order to measure the objective result of the drone, keeping the altitude immediately after the drone takes off according to the time, measure the movement value until the position is fixed and stable hovering is maintained and compared analyzed. Experimental results show that the drones can stably hover within 4cm horizontal and 2cm vertical from 50cm above the reference coordinates.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.289-290
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• 2017

본 논문에서는 드론이 비행중에 어떤 간섭이나, 방해로 인해 추락하게 되었을 때 아무런 안전장치가 없다면, 드론손상도 우려될 뿐더러 인명피해 등 사고가 발생할 수 있다는 점에서 접근하였다. 이를 예방하기 위해서 드론을 보호 할 수 있는 보호장치를 달아 드론을 보호할 수 있으며, 드론에 낙하산을 달아 어떤 위험상황으로 추락을 할 경우 낙하산이 펴지면서 드론을 보호하게 하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.381-382
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• 2019

본논문에서는 산업용 드론개발을 위한 안정성 향상에 대하여 연구하였다. 기존의 비행체의 경우 고신뢰도 대용량의 제어시스템을 이용하여 비행제어시스템을 구성하지만 무인 비행체는 소형 내장형시스템을 이용한다. 본 연구에서는 소형 무인 비행체에서 사용하는 소형 내장형 비행제어시스템에서 안정성을 개선하기 위한 방법으로 비행제어신호와 모터의 제어신호를 측정하여 안정상태와 이상상태를 구별한다. 제안한 방법은 기존의 비행제어시스템을 수정하지 않고 비행제어시스템의 감시가 가능 할 것으로 예상한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.259-260
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• 2019

4차산업이 본격화되면서 드론의 경제적 활용에 대하여 많은 관심이 집중되고 있다. 본 논문에서는 드론의 효율적 제어를 위하여 비행제어시스템의 운용프로그램인 비행제어 프로그램에 대하여 분석한다. 현재 오픈소스 비행 스택들을 다양한 비행제어기에 적용하기 위하여 다양한 기능들을 포함하고 있어 그 크기가 방대하다. 본 연구에서는 공개된 비행제어시스템을 분석하여 소형 무인 비행체인 드론에서 사용할 비행제어프로그램을 설계하고 구현하고자 한다. 제안한 비행제어프로그램은 구조가 간단하여 제어주기에 해당하는 루프타임을 줄일 수 있고, 특정 기능의 추가와 변경이 용이할 것으로 예상한다.

• The Journal of Korea Robotics Society
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• v.18 no.3
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• pp.233-240
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• 2023

In this paper, we proposed a hybrid type robot that simultaneously surveillance and reconnaissance on the ground and in the air. It was possible to expand the surveillance and reconnaissance range by expanding the surveillance and reconnaissance area of the ground robot and quickly moving to the hidden area through the drone. First, ground robots go to mission areas through drones and perform surveillance and reconnaissance missions for urban warfare or mountainous areas. Second, drones move ground robots quickly. It transmits surveillance and reconnaissance images of ground robots to the control system and performs reconnaissance missions at the same time. Finally, in order to secure the interoperability of these hybrid robots, basic performance and environmental performance were verified. The evaluation method was tested and verified based on the KS standards.