• 한국항행학회논문지
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• 제19권4호
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• pp.288-298
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• 2015

무인기 상용화를 위해서는 유인기 수준의 안전성을 확보할 수 있는 공중 및 지상 의 충돌경보 및 회피시스템 (sense and avoid or SAA) 개발과 검증이 필요하다. SAA 검증을 위한 비행시험은 높은 시험비용과 사고위험 때문에 많은 시험사례(test case)를 검토하기 어려우므로 시뮬레이션 시험으로 보완하는 것이 필수적이다. SAA 시뮬레이션 시험을 위해 flight simulator, Matlab/Simulink 시뮬레이터와 항전장비 시뮬레이션 모델들이 서로 연동하는 통합 무인기 시뮬레이션 환경을 구축하였다. 사례연구로서 TCAS 충돌경보 simulink 모델을 개발하고 Flight Gear와 연동하여 통합 무인기 시뮬레이션 환경을 구축하였고 이를 encounter model을 이용하여 검증하였다. 통합 무인기 시뮬레이션 환경을 활용하면 항전장비 개발주기의 개념설계 단계부터 부품 및 시스템의 성능/신뢰성 분석을 시작할 수 있다.

• 산업경영시스템학회지
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• 제38권4호
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• pp.212-225
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• 2015

UAV (Unmanned Aerial Vehicle), the pilotless plane or drone, draws researchers' attention at these days for its extended use to various area. The research was initiated for military use of the UAV, but the area of applicable field is extended to surveillance, communication, and even delivery for commercial use. As increasing the interest in UAV, the needs of research for operating the flying object which is not directly visible when it conducts a certain mission to remote place is obviously grown as much as developing high performance pilotless plane is required. One of the project supported by government is related to the use of UAV for logistics fields and controlling UAV to deliver the certain items to isolated or not-easy-to-access place is one of the important issues. At the initial stage of the project, the previous researches for controlling UAV need to be organized to understand current state of art in local researches. Thus, this study is one of the steps to develop the unmanned system for using in military or commercial. Specifically, we focused on reviewing the approaches of controlling UAV from origination to destination in previous in-country researches because the delivery involves the routing planning and the efficient and effective routing plan is critical to success to delivery mission using UAV. This routing plan includes the method to avoid the obstacles and reach the final destination without a crash. This research also present the classification and categorization of the papers and it could guide the researchers, who conduct researches and explore in comparable fields, to catch the current address of the research.

• 산업경영시스템학회지
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• 제44권3호
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• pp.64-72
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• 2021

Manned-unmanned teaming can be a very promising air-to-air combat tactic since it can maximize the advantage of combining human insight with the robustness of the machine. The rapid advances in artificial intelligence and autonomous control technology will speed up the development of manned-unmanned teaming air-to-air combat system. In this paper, we introduce a manned-unmanned teaming air-to-air combat tactic which is composed of a manned aircraft and an UAV. In this tactic, a manned aircraft equipped with radar is functioning both as a sensor to detect the hostile aircraft and as a controller to direct the UAV to engage the hostile aircraft. The UAV equipped with missiles is functioning as an actor to engage the hostile aircraft. We also developed a combat scenario of executing this tactic where the manned-unmanned teaming is engaging a hostile aircraft. The hostile aircraft is equipped with both missiles and radar. To demonstrate the efficiency of the tactic, we run the simulation of the scenario of the tactic. Using the simulation, we found the optimal formation and maneuver for the manned-unmanned teaming where the manned-unmanned teaming can survive while the hostile aircraft is shot-downed. The result of this study can provide an insight to how manned aircraft can collaborate with UAV to carry out air-to-air combat missions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권10호
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• pp.3858-3874
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• 2021

As an essential part of the urban transportation system, precise perception of the traffic flow parameters at the traffic signal intersection ensures traffic safety and fully improves the intersection's capacity. Traditional detection methods of road traffic flow parameter can be divided into the micro and the macro. The microscopic detection methods include geomagnetic induction coil technology, aerial detection technology based on the unmanned aerial vehicles (UAV) and camera video detection technology based on the fixed scene. The macroscopic detection methods include floating car data analysis technology. All the above methods have their advantages and disadvantages. Recently, indoor location methods based on wireless signals have attracted wide attention due to their applicability and low cost. This paper extends the wireless signal indoor location method to the outdoor intersection scene for traffic flow parameter estimation. In this paper, the detection scene is constructed at the intersection based on the received signal strength indication (RSSI) ranging technology extracted from the wireless signal. We extracted the RSSI data from the wireless signals sent to the road side unit (RSU) by the vehicle nodes, calibrated the RSSI ranging model, and finally obtained the traffic flow parameters of the intersection entrance road. We measured the average speed of traffic flow through multiple simulation experiments, the trajectory of traffic flow, and the spatiotemporal map at a single intersection inlet. Finally, we obtained the queue length of the inlet lane at the intersection. The simulation results of the experiment show that the RSSI ranging positioning method based on wireless signals can accurately estimate the traffic flow parameters at the intersection, which also provides a foundation for accurately estimating the traffic flow state in the future era of the Internet of Vehicles.

• 한국항행학회논문지
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• 제26권6호
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• pp.448-455
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• 2022

본 연구에서는 UTM(UAS Traffic Management) 체계 구축 시, 무인항공기 간의 비행 간격을 분리하기 위해 회랑(Corridor)을 설정하여야 하며, 통합시스템오차(TSE; Total System Error)를 고려하여 회랑 크기를 산출하였다. 복합형 수직이착륙 무인항공기를 이용하여 직선 구간과 선회 구간의 비행 데이터를 수집하였다. 비행 데이터는 SQSM(Scalar Quantity Summation Method) 방법을 통해 TSE를 도출하였으며, 항법시스템오차 (NSE; Navigation System Error) 와 비행기술오차 (FTE; Flight Technical Error)를 세부적으로 산출하여 직선 및 선회 구간에 대한 영향성을 분석하였다. 회랑 크기는 TSE 분석 결과와 PBN(Performance-based Navigation) manual을 참고하여 산출하였다.

• 한국ITS학회 논문지
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• 제16권6호
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• pp.182-194
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• 2017

그동안 교통관리에서 적용되던 드론 관련 연구는 도로나 차량을 검지하고 추적하는 연구가 대분이었다. 교통분야에서 영상이미지를 분석하는 목적은 기존 교통자료 수집체계(차량검지기, DSRC 등)의 한계를 극복하기 위함이다. 그런 의미에서 드론은 상당히 좋은 대안이나 최대 비행시간이 제한되어 있어 기존 수집체계를 대체하기 보다는 보완적 성격으로 활용되는 것이 타당하다. 따라서 교통조사분석을 위한 드론 활용방안에 대한 연구가 더 필요한 실정이다. 교통문제의 경우 특정 구간이나 지점에서 발생한 문제가 네트워크 전체로 확대되는 경우가 많아 드론을 이용하여 이러한 구간들에 대한 분석이 필요하다. 본 연구는 교통조사분석 활용을 위한 기초 연구로 드론으로 촬영된 고속도로 구간(800~1000m)을 단위 구간으로 분할하여 교통류 변수들을 추출하였다. 또한 영상기술의 발전으로 고고도에서 영상 촬영을 수행하였다.

• 산업경영시스템학회지
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• 제43권2호
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• pp.126-136
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• 2020

Recently, unmanned aerial vehicles (UAV, Drone) are highly regarded for their potential in the agricultural field, and research and development are actively conducted for various purposes. Therefore, in this study, to present a framework for tracking research trends in UAV use in the agricultural field, we secured a keyword search strategy and analyzed social network, a methodology used to analyze recent research trends or technological trends as an analysis model applied. This study consists of three stages. As a first step in data acquisition, search terms and search formulas were developed for experts in accordance with the Keyword Search Strategy. Data collection was conducted based on completed search terms and search expressions. As a second step, frequency analysis was conducted by country, academic field, and journal based on the number of thesis presentations. Finally, social network analysis was performed. The analysis used the open source programming language 'Python'. Thanks to the efficiency and convenience of unmanned aerial vehicles, this field is growing rapidly and China and the United States are leading global research. Korea ranked 18th, and bold investment in this field is needed to advance agriculture. The results of this study's analysis could be used as important information in government policy making.

• 한국농공학회논문집
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• 제61권4호
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• pp.1-10
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• 2019

Unmanned aerial vehicle(UAV) can acquire images with lower cost than conventional manned aircraft and commercial satellites. It has the advantage of acquiring high-resolution aerial images covering in the field area more than 50 ha. The purposes of this study is to develop the rice grain yield distribution using UAV. In order to develop a technology for estimating the rice yield using UAV images, time series UAV aerial images were taken at the paddy fields and the data were compared with the rice yield of the harvesting area for two rice varieties(Singdongjin, Dongjinchal). Correlations between the vegetation indices and rice yield were ranged from 0.8 to 0.95 in booting period. Accordingly, rice yield was estimated using UAV-derived vegetation indices($R^2=0.70$ in Sindongjin, $R^2=0.92$ in Donjinchal). It means that the rice yield estimation using UAV imagery can provide less cost and higher accuracy than other methods using combine with yield monitoring system and satellite imagery. In the future, it will be necessary to study a variety of information convergence and integration systems such as image, weather, and soil for efficient use of these information, along with research on preparing management practice work standards such as pest control and nutrient use based on UAV image information.

• Journal of electromagnetic engineering and science
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• 제19권1호
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• pp.48-55
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• 2019

Unmanned aerial vehicles (UAVs) using communications, sensors, and navigation equipment will play a key role in future warfare. Currently, UAVs are monitored to prevent misfire and accidents, and the conventional method adopted uses wires for data transmission and power supply. The repeated connection and disconnection of cables increases maintenance time and harms the connector. For convenience and stability, a wireless power transfer system to power UAVs is needed. Unlike other wireless power transfer (WPT) applications, the size of the receiving coils must be small, so that the WPT systems can be embedded inside space-limited UAVs. The small size reduces the coupling coefficient and transfer efficiency between the transmitting and the receiving coils. In this study, we propose a toroidal-shaped coil for a WPT system for UAVs with high coupling coefficient with minimum space requirements. For validation, conventional coils and the proposed toroidal-shaped coil were used and their coupling coefficient and power transfer efficiency were compared using simulated and measured results. The simulated and measured results were strongly correlated, confirming that the proposed WPT system significantly improved efficiency with negligible change in the space requirement.

• Smart Structures and Systems
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• 제24권5호
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• pp.669-681
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• 2019

Bridge collapses may deliver a huge impact on our society in a very negative way. Out of many reasons why bridges collapse, poor maintenance is becoming a main contributing factor to many recent collapses. Furthermore, the aging of bridges is able to make the situation much worse. In order to prevent this unwanted event, it is indispensable to conduct continuous bridge monitoring and timely maintenance. Visual inspection is the most widely used method, but it is heavily dependent on the experience of the inspectors. It is also time-consuming, labor-intensive, costly, disruptive, and even unsafe for the inspectors. In order to address its limitations, in recent years increasing interests have been paid to the use of unmanned aerial vehicles (UAVs), which is expected to make the inspection process safer, faster and more cost-effective. In addition, it can cover the area where it is too hard to reach by inspectors. However, this strategy is still in a primitive stage because there are many things to be addressed for real implementation. In this paper, a typical procedure of bridge inspection using UAVs consisting of three phases (i.e., pre-inspection, inspection, and post-inspection phases) and the detailed tasks by phase are described. Also, three major challenges, which are related to a UAV's flight, image data acquisition, and damage identification, respectively, are identified from a practical perspective (e.g., localization of a UAV under the bridge, high-quality image capture, etc.) and their possible solutions are discussed by examining recently developed or currently developing techniques such as the graph-based localization algorithm, and the image quality assessment and enhancement strategy. In particular, deep learning based algorithms such as R-CNN and Mask R-CNN for classifying, localizing and quantifying several damage types (e.g., cracks, corrosion, spalling, efflorescence, etc.) in an automatic manner are discussed. This strategy is based on a huge amount of image data obtained from unmanned inspection equipment consisting of the UAV and imaging devices (vision and IR cameras).