• Ecology and Resilient Infrastructure
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• v.9 no.3
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• pp.154-162
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• 2022

In this study, a technique for estimating water surface velocity fields in the Universal Transverse Mercator coordinate system using the GPS information of a propagating drone but not ground control points is developed. First, we determine the image direction in which the upper side of an image is directed based on the navigation information of the drone. Subsequently, we assign the start and end frames of the video used and determine the analysis range. Using these two frames, we segment the measurement cross-section into a few subsections at regular intervals. At these subsections, we analyze 30 frame images to create spatio-temporal volumes for calculating the velocity fields. The results of the developed method (propagating drone surface image velocimetry) are compared with those of the existing method (hovering drone surface image velocimetry), and relatively good agreement is indicated between both in terms of the velocity fields.

• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.3
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• pp.149-157
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• 2020

Regarding previously-developed drone simulators, it was easy to check their flight stability or controlling functions based on the condition that their weight was fixed from the design. However, the drone is largely classified into two types that is the one with the fixed weight whose purpose is recording video with camera and racing and another is whole weight-variable during flight with loading the articles for delivery and spraying pesticide though the weight of airframe is fixed. The purpose of this thesis is to analyze the structure of drone and its flight principle, suggest dynamics-model-based simulator that is capable of simulating weight-variable drone and develop the simulator that can be used for designing main control board, motor and transmission along the application of weight-variable drone. Weight-variable simulator was developed by using various calculation to apply flying method of drone to the simulator. First, ground coordinate system and airframe-fixing coordinate system were established and switching matrix of those two coordinates were made. Then, dynamics model of drone was established using the law of Newton and moment balance principle. Dynamics model was established in Simulink platform and simulation experiment was carried out by changing the weight of drone. In order to evaluate the validity of developed weight-variable simulator, it was compared to the results of clean flight public simulator against existing weight-fixed drone. Lastly, simulation test was performed with the developed weight-variable simulation by changing the weight of drone. It was found out that dynamics model controlled various flying positions of drone well from simulation and the possibility of securing the optimum condition of weight-variable drone that has flying stability and easiness of controlling.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.53-60
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• 2017

This paper is to design and implement the drone that supports a wideband multimedia communication and a long-range to save people in maritime. The drone is an Unnamed Aerial Vehicle (UAV) that is controlled by a radio wave not by people boarding the machine. We use the drone to respond quickly to the boating accident. To develop a smart drone for the high speed seamless video streaming in a long-range maritime, a necessary techniques are hardware design techniques that design structure of a drone, controlling techniques that operate a drone and communication techniques that control a drone in a long distance. In this paper, the limitations and techniques to design and implement the structure of drone supporting wideband multimedia communication for long-range maritime are explained. By expanding this communication drone network, it is aimed at improving utility of a drone.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.163-168
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• 2018

With the advent of the fourth industrial revolution era, the use of drone has been progressing rapidly in various fields. Now the drones will be used extensively in the area of investigation. Until now the criminal photographs stayed in 2D digital images, it would be possible to reproduce not only 3D images but also make a crime scene with 3D printer. Firstly, the video images taken by the investigation agency using the drones are digital image evidence, and the requirements for securing the evidence capability are not different from the conditions for obtaining the proof of digital evidence. However, when the drones become a new area of scientific investigation, it is essential to systematize the authenticity of the images taken by the drones so that they can be used as evidence. In this paper, I propose a method to secure the evidence capability of digital images taken by drone.

• Journal of the Korean Society of Safety
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• v.34 no.6
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• pp.88-95
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• 2019

It has been only a few years since drones have been introduced to Korea, and as the use of drones has increased in industrial sites as well as in hobby activities, accidents such as workers' body parts coming into contact with rotating propellers have been occurring since 2016. Industrial accident cases are being filed. In the case of a remote control vehicle, if you release the remote controller in the event of an abnormal situation, it stops in place and no further danger occurs but in case of drones flying over the sky is different. Sudden motor stops during flight, uncontrolled changes in flight posture, loss of radio waves, loose propeller, etc, numerous factors can lead to accidents due to unintentional movements. Therefore, drone operators need safety knowledge as well as high knowledge about drones. However, drones with a weight of less than 12 kg can fly without a pilot's certification, and therefore, a minimum accident prevention measure is required. 10 accidents approved as industrial accidents since 2016, 23 accidents surveyed by general drone operator, 40 accidents surveyed by the Korean Consumer Resources Unfortunately for the purpose of writing this paper, drones are a new species and do not have many parameters for analysis but my experience has shown that the type of disaster does not deviate significantly. In addition, there is no paper that analyzes drone related industrial accidents not only in Korea but also in other countries. However, even if you watch an overseas drone accident video through YouTube, it is not much different from the case that occurs in Korea. I hope that this study will be of little help to all the drone pilots as well as the work safety of industrial drones used in industrial sites.

• IEMEK Journal of Embedded Systems and Applications
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• v.18 no.3
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• pp.125-132
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• 2023

Roundabouts have strengths in traffic flow and safety but can present difficulties for inexperienced drivers. Demand to acquire and analyze drone images has increased to enhance a traffic environment allowing drivers to deal with roundabouts easily. In this paper, we propose a roundabout traffic analysis system that detects, tracks, and analyzes vehicles using a deep learning-based object detection model (YOLOv7) in drone images. About 3600 images for object detection model learning and testing were extracted and labeled from 1 hour of drone video. Through training diverse conditions and evaluating the performance of object detection models, we achieved an average precision (AP) of up to 97.2%. In addition, we utilized SORT (Simple Online and Realtime Tracking) and OC-SORT (Observation-Centric SORT), a real-time object tracking algorithm, which resulted in an average MOTA (Multiple Object Tracking Accuracy) of up to 89.2%. By implementing a method for measuring roundabout entry speed, we achieved an accuracy of 94.5%.

• Journal of Digital Convergence
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• v.16 no.4
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• pp.313-319
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• 2018

This experimental research explores the effect of drone's moving image on media audience's flow, arousal of interest and emotional state. Most previous researchers of media image effect insisted that camera movement should be abstained in order to give audience the feeling that movement of figures is in the contents story itself. and camera movement also can disturb natural viewing of audience. For the purpose of finding the effect of drone's moving image on media audience's flow, arousal of interest and emotional state, 2 groups of subjects composed of 56 university students were exposed to 2 different video clips, one with moving drone's image, the other with hovering drone's image. After this experiment, Questions which were designed to measure audience's flow, arousal of interest and emotional state were asked and analysed. This research found that subjects exposed to moving drone's image felt more interested and more positive emotional state than subjects exposed to hovering drone's image. However meaningful effect of drone's moving image on audience's flow was not found.

• Smart Media Journal
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• v.9 no.3
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• pp.130-141
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• 2020

The drone market in Korea is growing with a focus on the use of prevention, defense, exploration and surveying, search and rescue, video shooting, and facility management. However, the foreign dependence on drone's core technologies and components is high. Drone-powered countries such as the US and China are expanding the weaponization of drones, which can intensify trade wars between countries, such as strengthening import and export regulations and monopoly. Therefore, Korea should put R & D and localization of core technology, parts, and accessories of next generation drone first. For this, policy research and investment in infrastructure, equipment, and research personnel should be preceded. This study studied the evaluation of investment priorities by infrastructure sector (facility equipment, utilization field, and demand manpower) to foster small drone companies through literature studies. To this end, we expanded and reclassified e isting research, developed investment prioritization indicators through expert group interviews and reviews, derived future uncertainties, and selected investment priorities by infrastructure sector using AHP techniques. Finally, it proposed an infrastructure construction strategy to foster small drone companies in terms of drone development support, utilization support.

• Journal of Korean Society of Disaster and Security
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• v.10 no.1
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• pp.67-74
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• 2017

Drone technology has been used in various fields including personal hobby, pesticide application and shipping etc. However, only few drone technologies are used in restricted fields such as transportation of alimony goods and utilization of video because of the limited utilization aspect of disaster management field. Especially, disaster specialists' the lack of understanding of the drones seems to increase the difficulty of activating drone technology in disaster management. The theme of the thesis aims to share outline of drones' control method and education plan. This project also analysis the reasons why drone has not been used in disaster management with the fact that drone can be a vital part of emergency management. We propose improved application plan to use drone technology and future development direction in disaster management by deriving problems in terms of institutional aspects(regulation and education) and sensor-based application problems camera, thermal camera, infrared sensor, RFID.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.3
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• pp.171-176
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• 2019

Drones are highly utilized because they can efficiently acquire long-distance videos. In drone operation, the speed, which is the magnitude of the velocity, can be set, but the moving direction cannot be set, so accurate information about the drone's movement should be estimated. In this paper, we estimate the velocity of the drone moving at a constant speed and direction. In order to estimate the drone's velocity, the displacement of the target frame to minimize the sum of absolute difference (SAD) of the reference frame and the target frame is obtained. The ground truth of the drone's velocity is calculated using the position of a certain matching point over all frames. In the experiments, a video was obtained from the drone moving at a constant speed at a height of 150 meters. The root mean squared error (RMSE) of the estimated velocities in x and y directions and the RMSE of the speed were obtained showing the reliability of the proposed method.