• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.133-143
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• 2023

As drones (also known as UAV) become popular with advanced information and communication technology (ICT), they have been utilized for various fields (agriculture, architecture, and so on). However, malicious attackers with advanced drones may pose a threat to critical national infrastructures. Thus, anti-drone systems have been developed to respond to drone threats. In particular, remote identification data (R-ID)-based UAV detection and identification systems that detect and identify illegal drones with R-ID broadcasted by drones have been developed, and are widely employed worldwide. However, this R-ID-based UAV detection/identification system is vulnerable to security due to wireless broadcast characteristics. In this paper, we analyze the security vulnerabilities of DJI Aeroscope, a representative example of the R-ID-based UAV detection and identification system, and propose a replay-attack-based neutralization method using the analyzed vulnerabilities. To validate the proposed method, it is implemented as a software program, and verified against four types of attacks in real test environments. The results demonstrate that the proposed neutralization method is an effective neutralization method for R-ID-based UAV detection and identification systems.

• Journal of the Korea Society of Computer and Information
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• v.24 no.4
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• pp.91-97
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• 2019

Recently, UAV manufacturers are developing UAV system in a form that can be controlled by CS regardless of UAV kind and using STANAG 4586 interface standard considering Interoperability. STANAG 4586 is a NATO military standard developed to control various UAVs with standardized equipment. In such a case, UAV handover will inevitably occur and it is one of the most important function for safe UAV flight in platform using STANAG 4586. In the future combat situation where collaboration between AV and UAV is anticipated, seamless handover of UAV is a part of continuous research. In this paper, we propose requirements for UAV handover based on ARP 4761 safety assessment and analyze feasibility of the requirements by comparing UAV handover process in STANAG 4586. As a result of the comparative analysis, the proposed handover requirements based on ARP 4761 includes all the handover procedures of STANAG 4586 and present additional considerations for SOP creation and CS development. Applying the proposed handover requirements in the UAV development process can reduce the probability of loss of UAV control over the handover process and it can be expected to help improve the safety of UAV.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1868-1875
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• 2016

This paper presents the mega trends of technology and competitiveness analysis results based on patent analysis for establishing effective research and development (R&D) strategy on UAV (Unmanned Aerial Vehicle) in the aerial ICT industry. In order to analyze mega trends of UAV technologies, patent analysis is conducted focusing on published/registered patents of Korea, the U.S., Japan, and Europe. We divided the target technologies into 3 main category levels based on the converging technology of UAV and ICT. The 3,433 patents are collected. Patent indicators such as patent activity (PA), cites per patent (CPP), and major market expansion (MME) are extracted for grasping the technology competitiveness and Korea's competitiveness per sub category levels of UAV. We suggest the R&D strategy of each technology areas based on patent analysis results. We analyzed Korea's technology levels, advanced companies' R&D trends, and patent trends through patent information and expected that this paper would be utilized for establishment of R&D strategy of UAV in the future.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.37-38
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• 2017

최근 방제 및 예찰과 같은 농작업에 단일 UAV(Unmanned Aerial Vehicle)시스템이 적용되고 있지만, 가반하중과 체공시간 등 기존시스템의 문제가 점차 대두되면서 작업 시간을 보다 단축시키고 작업 효율을 극대화 할 수 있는 농업용 멀티 UAV시스템의 필요성이 증대되고 있다. 본 논문에서는 작업자가 다수의 농업용 UAV를 효과적으로 제어할 수 있는 분산군집제어 알고리즘을 제안하며 알고리즘 검증 및 평가를 위한 시뮬레이터를 소개한다. 분산군집제어는 UAV 제어 계층, VP(Virtual Point) 제어 계층, 원격제어 계층으로 이루어진 3계층 제어구조를 가진다. UAV 제어 계층에서 각 UAV는 point mass로 모델링 되는 VP의 이상적인 경로를 추종하도록 제어한다. VP 제어 계층에서 각 VP는 입력 $p_i(t)=u^c_i+u^o_i+u^{co}_i+u^h_i$-(1)을 받아 제어되는데 여기서, $u^c_i{\in}{\mathbb{R}}^3$는 VP 사이의 충돌방지제어, $u^o_i{\in}{\mathbb{R}}^3$는 장애물과의 충돌방지제어, $u^{co}_i{\in}{\mathbb{R}}^3$는 UAV 상호간의 협조제어, $u^h_i{\in}{\mathbb{R}}^3$는 작업자로부터의 원격제어명령이다. (1)의 제어입력에서 충돌방지제어는 각 $u^i_c:=-{\sum\limits_{j{\in}{\eta}_i}}{\frac {{\partial}{\phi}_{ij}^c({\parallel}p_i-p_j{\parallel})^T}{{\partial}p_i}}$-(2), $u^o_c:=-{\sum\limits_{r{\in}O_i}}{\frac {{\partial}{\phi}_{ir}^o({\parallel}p_i-p^o_r{\parallel})^T}{{\partial}p_i}}$-(3)로 정의되면 ${\phi}^c_{ij}$와 ${\phi}^o_{ir}$는 포텐셜 함수를 나타낸다. 원격제어 계층에서 작업자는 햅틱 인터페이스를 통해 VP의 속도를 제어하게 된다. 이때 스케일변수 ${\lambda}$에 대하여 VP의 원격제어명령은 $u^t_i(t)={\lambda}q(t)$로 정의한다. UAV 시뮬레이터는 리눅스 환경에서 ROS(Robot Operating Systems)를 기반한 3차원 시뮬레이터인 Gazebo상에 구축하였으며, 마스터와 슬레이브 간의 제어 명령은 TCPROS를 통해 서로 주고받는다. UAV는 PX4 기반의 3DR Solo 모델을 사용하였으며 MAVROS를 통해 MAVLink 통신 프로토콜에 접속하여 UAV의 고도, 속도 및 가속도 등의 상태정보를 받을 수 있다. 현재 멀티 드론 시스템을 Gazebo 환경에 구축하였으며, 추후 시뮬레이터 상에 분산군집제어 알고리즘을 구현하여 검증 및 평가를 진행하고자 한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.2
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• pp.301-307
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• 2018

Unmanned Aerial Vehicles (i.e., drone) are gaining a lot of interest from a wide range of application domains such as infrastructure monitoring and parcel delivery service. In those service scenarios, multiple UAVs are involved and should be reliably operated by so-called UAV management system. For that, we propose oneM2M standard based UAV management and control system which is specifically targeted at traffic management of low-altitude UAVs. In this paper, we include oneM2M platform architecture and its implementation for UAV management system in conjunction with UAV interworking procedure.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.495-502
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• 2016

Italian Ryegrass (IRG), which is known as high yielding and the highest quality winter annual forage crop, is grown in mid-south area in Korea. The objective of this study was to evaluate the use of unmanned aerial vehicle (UAV) for the monitoring IRG growth. Unmanned aerial vehicle imagery obtained from middle March to late May in Nonsan, Chungcheongnam-do. Unmanned aerial vehicle imagery corrected geometrically and atmospherically to calculate normalized difference vegetation index (NDVI). We analyzed the relationships between $NDVI_{UAV}$ of IRG and biophysical measurements such as plant height, fresh weight, and dry weight over an entire IRG growth period. The similar trend between $NDVI_{UAV}$ and growth parameters was shown. Correlation analysis between $NDVI_{UAV}$ and IRG growth parameters revealed that $NDVI_{UAV}$ was highly correlated with fresh weight (r=0.988), plant height (r=0.925), and dry weight (r=0.853). According to the relationship among growth parameters and $NDVI_{UAV}$, the temporal variation of $NDVI_{UAV}$ was significant to interpret IRG growth. Four different regression models, such as (1) Linear regression function, (2) Linear regression through the origin, (3) Power function, and (4) Logistic function were developed to evaluate the relationship between temporal $NDVI_{UAV}$ and measured IRG growth parameters. The power function provided higher accurate results to predict growth parameters than linear or logistic functions using coefficient of determination. The spatial distribution map of IRG growth was in strong agreement with the field measurements in terms of geographical variation and relative numerical values when $NDVI_{UAV}$ was applied to power function. From these results, $NDVI_{UAV}$ can be used as a new tool for monitoring IRG growth.

• Journal of Korean Society of Forest Science
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• v.112 no.3
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• pp.363-373
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• 2023

Forest biomass surveys are regularly conducted to assess and manage forests as carbon sinks. LiDAR (Light Detection and Ranging), a remote sensing technology, has attracted considerable attention, as it allows for objective acquisition of forest structure information with minimal labor. In this study, we propose a method for estimating overstory and understory biomass in forest stands using backpack laser scanning (BPLS) and unmanned aerial vehicle laser scanning (UAV-LS), and assessed its accuracy. For overstory biomass, we analyzed the accuracy of BPLS and UAV-LS in estimating diameter at breast height (DBH) and tree height. For understory biomass, we developed a multiple regression model for estimating understory biomass using the best combination of vertical structure metrics extracted from the BPLS data. The results indicated that BPLS provided accurate estimations of DBH (R² =0.92), but underestimated tree height (R² =0.63, bias=-5.56 m), whereas UAV-LS showed strong performance in estimating tree height (R² =0.91). For understory biomass, metrics representing the mean height of the points and the point density of the fourth layer were selected to develop the model. The cross-validation result of the understory biomass estimation model showed a coefficient of determination of 0.68. The study findings suggest that the proposed overstory and understory biomass survey methods using BPLS and UAV-LS can effectively replace traditional biomass survey methods.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.83-90
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• 2020

Disasters are causing significant damage to the lives and property of our society and are recognized as social problems that need to be solved nationally and globally. The 4th industrial revolution technologies affecting society as a whole such as the Internet of Things(IoT), Artificial Intelligence(AI), Drones(Unmanned Aerial Vehicles), and Big Data are continuously absorbed into the disaster and safety industries as scientific and technological tools for solving social problems. Very soon, twenty-nine domestic UAV-related organizations/companies will complete the construction of a multicopter type small UAV integrated system ('17~'20) that can be operated at disaster and security sites. The current work considers and proposes the mid-to-long term R&D direction of disaster UAV as a strategic asset of the national disaster response system. First, the trends of disaster and safety industry and policy are analyzed. Subsequently, the development status and future plans of small UAV, securing shortage technology, and strengthening competitiveness are analyzed. Finally, step-by-step R&D direction of disaster UAV in terms of development strategy, specialized mission, platform, communication, and control and operation is proposed.

• 한국전산유체공학회:학술대회논문집
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• 2002.10a
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• pp.8-16
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• 2002

Now, the era of information, the rapid acquisition of vast and various information acts as a key role. for the national competitiveness. The smart UAV is brought to the fore as a new future technology which will be able to satisfy the information needs in broad and stereoscopic manner. The smart UAV, with VTOL capability, higher performance, and reliability over the existing technology thresholds, will lead the aerospace technology in the future. In this paper, the technology concept of smart UAV, the necessity of development, and the trend of worldwide R&D are introduced and analyzed. In addition, for the Smart UAV Development Program which is launched by the 21c Frontier R&D program this year, the role and application area of the CFD will be discussed.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.475-477
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• 2017

최근 ICT 기술 발전으로 인해여 전세계에서 UAV 시장이 기하급수적으로 성장하고 있다. 실제로 미국의 Teal Group에 따르면 2024년 전세계 UVA 시장은 147억 달러에 이를 것이라 예상하고 있다. 그러나 UAV는 현재 많은 분야에서 이용되고 있지만, 대부분 저사양을 가지고 있어 복잡한 임무를 수행 할 수 없다. 이러한 문제를 해결하기 위해서는 여러 UAV가 임무를 분담 수행하는 UAV 군집 비행 제어 기술이 필수적이다. 본 논문에서는 기존 UAV 군집 비행 제어 기술을 3가지로 분류하고 향상된 복잡 UAV 군집 비행 제어 기술을 제안한다.