• Journal of IKEEE
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• v.27 no.4
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• pp.425-429
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• 2023

In this paper, the scheme to activate the active elements of reconfigurable intelligent surface(RIS) is proposed. Recently, RIS has been studied as a technology that improves communication coverage and spectral efficiency in wireless communication system. RIS can adjust the phase and amplitude of the received signal, and can ensure better communication performance in areas with many obstacles, such as urban areas. However, due to RIS, the signal undergoes fading twice and performance decrease in communication. Recently, RIS using active reflection elements has been studied to solve these problems. However, if the entire RIS is used as an active reflection element, energy consumption increases. Accordingly, in this paper, we propose a system that utilizes some of the RIS reflective elements as active reflective elements and a scheme for selecting active reflective elements to be activated.

• Smart Media Journal
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• v.12 no.9
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• pp.159-170
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• 2023

It takes a lot of time and manpower to search for the missing. As part of the solution, a missing person search AI system was implemented using a YOLO-based model. In order to train object detection models, the model was learned by collecting recognition images (road fixation) of drone mobile objects from AI-Hub. Additional mountainous terrain datasets were also collected to evaluate performance in training datasets and other environments. In order to optimize the missing person search AI system, performance evaluation based on model size and hyperparameters and additional performance evaluation for concerns about overfitting were conducted. As a result of performance evaluation, it was confirmed that the YOLOv5-L model showed excellent performance, and the performance of the model was further improved by applying data augmentation techniques. Since then, the web service has been applied with the YOLOv5-L model that applies data augmentation techniques to increase the efficiency of searching for missing people.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.2
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• pp.315-326
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• 2017

Four quadrotor UAVs are maneuvered to guide four animals into their pen within the minimum time by creating noises of predators modeled with an exponential function. The quadrotor UAVs are controlled via PID controllers, follow time optimal trajectories, and avoid collisions through altitude separations. The stability of the proposed PID controller is analyzed and verified using MATLAB/Simulink based simulations. Proposed step by step strategies would be practical solutions of actual cattle roundup problems.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.301-302
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• 2018

본 논문에서는 대한민국 공항 관제권 구역과 비행금지구역을 표시하는 API를 이용하여 드론비행금지구역을 나타내는 서비스를 구현한 결과를 보인다. GIS(Geographic Information System) 응용 프로그램인 QGIS에 WMS(Web Map Service)를 이용하여 오픈 API를 연동하였다. 항공정보도 API로부터 얻은 관제권 및 비행금지구역, 비행제한구역 레이어 등을 결합하여 드론 비행금지구역에 대한 데이터를 가진 새로운 레이어를 생성하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.581-584
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• 2015

드론은 GPS 포인트를 기반으로 무인비행이 가능하다. 이 특징을 활용하는 방안의 하나로서, 우리는 해양사고에서의 인명구조를 대상으로 하였다. 구명조끼를 GPS 신호발생기로 구현하고, 이를 이용한 웨이포인트를 설정함으로써, 드론으로하여금 재난자에게 우선 접근할 수 있도록 구현할 수 있다. 이를 실제 구현하기 위해서는 GPS 신호를 드론의 웨이포인트값으로 바꾸어 넣어주는 소프트웨어적 모듈이 요구되며, 본 연구에서 이를 구현하고자 한다. 우리는 3D 로보틱스의 Quadcopter와 그를 지원하는 Pixhawk를 사용하였다.

• International journal of advanced smart convergence
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• v.12 no.1
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• pp.31-40
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• 2023

This asymed drone controller is indispensable for two components: Guidance and Controller. In which the Ministry of Guidance will receive waypoints from which to form an orbit then combine the data with the current location of the vessel, thereby calculating and also supplying the controller to drive the vehicle to follow the outlined trajectory. This article will use the Line Of Sight (LOS) algorithm to design the Guidance and Controller sets. The result as well as the effectiveness of the controller will be shown through matlab/SIMULINK simulation.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.121-123
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• 2017

드론은 군사목적에서 개발되고 사용되어 왔으나 현재에는 촬영, 물류 등의 다양한 분야에서 연구 및 사용되고 있다. 앞으로 수많은 드론이 하늘에서 비행할 것으로 예상됨에 따라 때때로 비슷한 항로를 비행하는 드론간의 충돌 위험 또한 야기될 수 있다. 드론을 안전하게 비행하기 위한 많은 연구들이 진해되어 왔지만 공중 충돌에 의한 피해를 최소화 하려는 연구의 진행은 초기상태에 있다. 본 논문은 민간 항공기에 적용되어 사용되고 있는 1030/1090MHz 대역의 TCAS 시스템을 433MHz LoRa 네트워크를 사용하여 구현하였다. 충돌 위험을 판단하는 근거는 비행준인 드론의 진행 방향 및 비행 고도를 통하여 산출한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.968-971
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• 2018

본 논문에선 드론의 장거리 비행을 합리적으로 수행하기 위한 배터리 교환 스테이션과 스테이션으로의 비행 유도와 균일화된 배터리 형태를 제공해줄 배터리 팩의 개발을 제안하고자 한다. 장거리 비행을 필요로 하는 드론은 제시된 배터리 팩을 사용하여 주변의 배터리 교환 스테이션을 이용할 수 있다. 드론은 주기적으로 배터리를 교환받으므로 장거리 비행 임무를 수행할 수 있게 된다.

• International Journal of Computer Science & Network Security
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• v.23 no.8
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• pp.107-112
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• 2023

World is moving towards digitization at a rapid pace, so the enterprises have developed information systems for management of their business. Empowering educational institutes with information systems are become very important and vital. Doing everything manually is very difficult for students, teachers and staff. Information system can enhance their efficiency and save a lot of time; this research proposed system will solve this issue by providing services like class room reservation, e-library facility, online submission etc. in a secured environment. Up till now limited attention has been paid to utilize robots and drones for automation inside educational institutes. Our proposed system incorporates robots and drones to fill this gap in automation being used in institutes. Through this research, the aim is to improve the efficiency of learning and services in educational institutions or universities.

• The Korean Journal of Air & Space Law and Policy
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• v.34 no.1
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• pp.235-268
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• 2019

Under the Aviation Safety Act of Korea, any person who intends to operate a drone is required to follow the operational conditions listed below, unless approved by the Minister of Land, Infrastructure, Transport and Tourism; (i) Operation of drones in the daytime, (ii) Operation of drones within Visual Line of Sight, (iii) Maintenance of a certain operating distance between drones and persons or properties on the ground/ water surface, (iv) Do not operate drones over event sites where many people gather, (v) Do not transport hazardous materials such as explosives by drone, (vi) Do not drop any objects from drones. Requirements stated in "Airspace in which Flights are Prohibited" and "Operational Limitations" are not applied to flights for search and rescue operations by public organizations in case of accidents and disasters. This paper analyzes legal issues as to definition and regulations of drones in Korean Aviation Safety Act. This paper, also, offers some implications and suggestions for regulations of drones under Korean Aviation Safety Act by comparing the regulations of drones in Japanese Civil Aeronautics Act.