• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.965-968
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• 2017

드론이라고도 불리는 소형 무인기는 비전 시스템을 대부분 갖추고 있어 비전을 응용한 기술이 적합한 플랫폼이며 특히 랜드 마크 기반 위치 추적 방법은 드론과 지상 로봇과 같은 다른 플랫폼 간의 협업을 위한 효율적인 방법 중 하나이다. 본 논문에서는 드론과 지상 로봇의 협업 시스템을 위하여 기준 마커를 검출하는 연구에 대하여 서술한다. 기준 마커 중 하나인 ArUco는 바코드보다 간단한 내부 코드를 가지고 있다. 기준 마커의 카메라 캘리브레이션을 통하여 카메라와 마커의 자세 추정이 가능하다. 성능 평가 실험을 통하여 형태가 간단한 마커, AprilTags, ArUco 간 성능 비교를 하였고 92%의 정확도를 얻어내었으며 ArUco의 적합한 이진화 알고리즘을 제시하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.335-337
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• 2021

최근 드론의 용도는 취미, 공연, 농업, 안전, 군사, 연구, 물자수송 등 다양한 분야와 목적으로 활용되고 있다. 더불어 드론의 불법적 활용으로 인한 안전 및 법적 문제 또한 빈번히 발생하고 있어, 이런 문제들을 예방하기 위한 드론의 탐지 기술이 활발히 연구되고 있다. 본 논문은 카메라로 촬영된 영상에서 조류와 같은 다른 객체와 구별하여 드론을 탐지하는 기술과 상공에서 바라본 객체들을 탐지하는 기술을 구현한다. 제안 방법은 딥러닝 기반의 YOLOv4를 사용하였다. UAV_123 데이터세트로 학습한 실험 결과, mAP는 85%, Recall은 85%, Precision은 81%의 정확도를 보였다. 제안 방법은 인명 구조, 배송, 건축 뿐만 아니라 안티 드론 시장에서도 효과적으로 활용될 수 있을 것으로 기대된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.572-573
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• 2021

By optimizing the development of IoT-type thermal image-based photovoltaic fault detection equipment and interworking with drones using a drone with an intelligent path movement function, real-time analysis of the acquired image data facilitates fault reading of solar power plants. , design a system that can read out the failure of a solar panel using the image subtraction analysis technique and the presentation of the basic technology that can improve the power generation rate of the solar power plant and make an efficient maintenance model.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.408-410
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• 2022

최근 데이터 획득 위치에 가장 근접하고, 저 수준의 계산력을 제공하는 엣지 기기를 중심으로 직접 딥러닝 추론을 수행하고자 하는 요구가 증가하고 있다. 본 논문에서는 드론에서 촬영한 교통 영상 데이터를 기반으로, 다수의 차량 종류 및 보행자를 식별하는 모델을 Jetson Nano 에 탑재하여 기본 성능을 측정한다. 더불어, 자원제약형 기기 환경에서 TensorRT 와 Deepstream 을 활용하여 객체 식별 모델의 연산 경량화 및 추론 가속화 성능을 극대화하기 위한 구현 및 실험을 수행하여 Anchor-based 및 Anchor-free 객체 식별 모델의 정확도와 실시간 대응력을 평가하고 논의한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.928-929
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• 2023

도로 교통 사고 및 교통 정체는 도로 상황의 비정상적인 요인으로 인해 발생하는 심각한 문제이다. 이러한 문제를 해결하기 위해 도로 상황을 실시간으로 감지하고 사용자에게 알리는 시스템이 필요하다고 판단된다. 본 연구는 도로 상황 감지 및 예방을 위한 새로운 접근 방식을 제안하며, 이에 대한 배경과 필요성, 그리고 프로젝트의 특장점을 소개한다.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.667-677
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• 2020

Crop water stress can be detected based on soil moisture content, crop physiological characteristics and remote-sensing technology. The detection of crop water stress is an important issue for the accurate assessment of yield decline. The crop water stress index (CWSI) has been introduced based on the difference between leaf and air temperature. In this paper, drone-based thermal infrared image was used to map of crop water stress in water control plot (WCP) and water deficit plot (WDP) over spring chinese cabbage fields. The spatial distribution map of CWSI was in strong agreement with the abnormal growth response factors (plant height, plant diameter, and measured value by chlorophyll meter). From these results, CWSI can be used as a good method for evaluation of crop abnormal growth monitoring.

• Journal of Aerospace System Engineering
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• v.16 no.1
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• pp.49-55
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• 2022

The role of drones has been expanded to various fields such as agriculture, construction, and logistics. In particular, agriculture drones are emerging as an effective alternative to solve the problem of labor shortage and reduce the input cost. In this study therefore, we proposed the fruit recognition algorithm and harvesting mechanism for fruit harvesting drone system that can safely harvest fruits at high positions. In the fruit recognition algorithm, we employ "You-Only-Look-Once" which is a deep learning-based object detection algorithm and verify its feasibility by establishing a virtual simulation environment. In addition, we propose the fruit harvesting mechanism which can be operated by a single driving motor. The rotational motion of the motor is converted into a linear motion by the scotch yoke, and the opened gripper moves forward, grips a fruit and rotates it for harvesting. The feasibility of the proposed mechanism is verified by performing Multi-body dynamics analysis.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.74-91
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• 2023

Several that analyzed the effectiveness of traffic safety facilities a method of comparing changes in the number of accidents, accident severity, speed through traffic accident data before and after installation or speed data collected from vehicle detection systems (VDS). , when traffic accident data is used, it takes a long time to collect because must be collected for at least one year before and after installation. , the road environment may change during this period, such as the addition of other traffic safety facilities in addition to the facilities to be analyzed. , the location of the VDSs for speed data is often different from the location where analysis is required, and there is a problem in that the investigators are exposed to the risk of traffic accident during on-site investigation. Therefore, this study a case study by establishing a methodology to determine effectiveness video images with a drone, extracting data using a program, and comparing vehicle driving speeds before and after speed reduction facilities. Vehicle speed surveys using drones are much safer than observational surveys conducted on highways and have the advantage of tracking speed changes along the vehicle, it is expected that they will be used for various traffic surveys in the future.

• Korean Journal of Remote Sensing
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• v.40 no.3
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• pp.275-284
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• 2024

Monitoring crop growth changes and water content is crucial in the agricultural sector. This study utilized drones equipped with Short Wavelength Infrared (SWIR) sensors, sensitive to moisture changes, to observe soybeans' growth and water content variations. We confirmed that as soybeans grow more vigorously, their water content increases and differences in irrigation levels lead to decreases in vegetation and moisture indices. This suggests that waterlogging slows down soybean growth and reduces water content, highlighting the importance of detailed monitoring of vegetation and moisture indices at different growth stages to enhance crop productivity and minimize damage from waterlogging. Such monitoring could also preemptively detect and prevent the adverse effects of moisture changes, such as droughts, on crop growth. By demonstrating the potential for early diagnosis of moisture stress using drone-based SWIR sensors, this research suggests improvements in the efficiency of large-scale crop management and increases in yield, contributing to agricultural production.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.3
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• pp.456-463
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• 2021

In this paper, Ultra Wide-Band(UWB) radar sensor is employed to detect flying drones and avoid collision in dense clutter environments. UWB signal is preferred when high resolution range measurement is required for moving targets. However, the time varying motion of flying drones may increase clutter noises in return signals and deteriorates the target detection performance, which lead to the performance degradation of anti-collision radars. We adopt a dynamic clutter suppression algorithm to estimate the time-varying distances to the moving drones with enhanced accuracy. A modified Constant False Alarm Rate(CFAR) is developed using an adaptive filter algorithm to suppress clutter while the false detection performance is well maintained. For this purpose, a velocity dependent CFAR algorithm is implemented to eliminate the clutter noise against dynamic target motions. Experiments are performed against flying drones having arbitrary trajectories to verify the performance improvement.