• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.2A
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• pp.66-79
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• 2005

In this paper, we have performed the analysis of RF transceiver system and communication link for the improvement in reliability of Smart-UAV(Unmanned Aerial Vehicles) Data-Link. The system analysis performed using the development specification of the data link and data sheet of using components through the system simulation tool that is Agilent EEsof ADS. Also, the communication link analysis peformed using a variety of propagation models for the smart UAV operation environments. As a result, we have presented problems appeared in the simulation results and development specification. As well as, we have presented about several problems and consideration issue for system design through the communication link analysis.

• Current Industrial and Technological Trends in Aerospace
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• v.4 no.1
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• pp.55-60
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• 2006

헬리콥터와 같은 전통적인 수직이착륙항공기는 이착륙시 활주로가 필요로 하지 않는 장점이 있으나 고 속비행 및 고고도 성능에 있어서는 고정익기에 뒤떨어진다. 고효율의 엔진개발에 따라 고정익 항공기가 최 대속도 및 성능이 비약적으로 발전한대 비해, 헬리콥터의 최대속도는 160 ~170 kts (300~315 km/h) 수 준으로 제한되어왔고 장거리 운항에서 필수적인 고고도 운항능력에 있어서도 4km 이상의 고도에서 효율 적인 비행을 수행하는 데에는 한계가 있다. 이를 극복하기 위해 지난 반세기 동안 다양한 신개념 비행체 연 구가 수행되었다. 스마트무인기기술개발사업단에서는 항공선진국의 이러한 연구개발동향 및 그 결과를 종 합하여 미래적 신개념 비행체 대안을 모색하였고, 그 결과 틸트로터 개념을 선정하여 상세설계를 종료한 상태이다. 이러한 경과에 대한 요약과 현재 활발히 진행중인 항공선진국의 미래형 수직이착륙 항공기 개발 기종의 현황, 성능비교를 통해 고속, 고고도 수직이착륙 항공기 개발에 관한 세계적 추세와 본 사업의 연관 성을 고찰해 보았다.

• Aerospace Engineering and Technology
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• v.8 no.1
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• pp.1-9
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• 2009

The ground integration test of Smart UAV has been performed according to the flight test plan. The flight test of full scaled model will be performed followed by 4 DOF ground rig test and a tethered hover test. Smart UAV is the first indigenous tiltrotor aircraft which can fly with fast cruise speed and take off or land vertically. In order to prove the flight control law of Smart UAV, the 40% scaled airplane was developed and have been tested. During flight test of small scaled model, many unique and unexpected problems occurred. After clearing these problems, fully automatic flight test was performed successfully. The experiences about many trouble shooting and resolving the problems would be basic material to avoid the unexpected but similar flight test problems hidden behind of the full scaled Smart UAV. This paper presents the detailed procedures of trouble shootings to solve the unique problems which occurred during the flight test of small scaled tiltrotor UAV.

• Korean Journal of Remote Sensing
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• v.36 no.6_1
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• pp.1393-1405
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• 2020

UAV (Unmanned Aerial Vehicle) can acquire high-resolution images due to low-altitude flight, and it can be photographed at any time. Therefore, the UAV images can be updated at any time in map production. Due to these advantages, studies on the possibility of producing large-scale digital maps using UAV images are actively being conducted. Precise digital maps can be used as base data for digital twins or smart cites. For producing a precise digital map, precise sensor modeling using GCPs (Ground Control Points) must be preceded. In this study, geometric models of UAV images were established through a precision sensor modeling algorithm developed in house. Then, a digital map by stereo plotting was produced to evaluate the possibility of large-scale digital map. For this study, images and GCPs were acquired for Ganseok-dong, Incheon and Yeouido, Seoul. As a result of precision sensor modeling accuracy analysis, high accuracy was confirmed within 3 pixels of the average error of the checkpoints and 4 pixels of the RMSE was confirmed for the two study regions. As a result of the mapping accuracy analysis, it satisfied the 1:1,000 mapping accuracy announced by the NGII (National Geographic information Institute). Therefore, the precision sensor modeling technology suggested the possibility of producing a 1:1,000 large-scale digital map by UAV images.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.1
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• pp.65-73
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• 2006

The high temperature occurs due to the combustion gas from engine in unmanned aerial vehicles (UAV). The high temperature may cause serious damages in UAV structure. The Functionally Graded Material (FGM) is chosen as a candidate material of the engine duct structure. A functionally graded material (FGM) is a two- component mixture composed by compositional gradient materials from one material to the other. In contrast, traditional composite materials are homogeneous mixtures, and involve compositions between the desirable properties of the component materials. Since significant proportions of an FGM contain the pure form of each material, the need for compromise is eliminated. The properties of both components can be fully utilized. Thermal stress analysis of FGM layers (20, 40, 60, 80 and 100) is performed in this paper. In addition, the creep behavior of FGM applied in duct structure of an engine is analyzed for better understanding of FGM characteristics.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.63-80
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• 2022

As a technology to analyze and predict an issue has been developed by constructing real space into virtual space, it is becoming more important to acquire precise spatial information in complex cities. In this study, images were acquired using an unmanned aerial vehicle for urban area with complex landscapes, and land cover classification was performed object-based image analysis and semantic segmentation techniques, which were image classification technique suitable for high-resolution imagery. In addition, based on the imagery collected at the same time, the replicability of land cover classification of each artificial intelligence (AI) model was examined for areas that AI model did not learn. When the AI models are trained on the training site, the land cover classification accuracy is analyzed to be 89.3% for OBIA-RF, 85.0% for OBIA-DNN, and 95.3% for U-Net. When the AI models are applied to the replicability assessment site to evaluate replicability, the accuracy of OBIA-RF decreased by 7%, OBIA-DNN by 2.1% and U-Net by 2.3%. It is found that U-Net, which considers both morphological and spectroscopic characteristics, performs well in land cover classification accuracy and replicability evaluation. As precise spatial information becomes important, the results of this study are expected to contribute to urban environment research as a basic data generation method.

• The Journal of the Korea Contents Association
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• v.18 no.6
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• pp.303-313
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• 2018

The purpose of this study is digitalization of earthwork such as development of 3D terrain analysis platform using latest technologies including unmanned aerial vehicle and terrestrial laser scanner to ultimately achieve earthwork automation. It is necessary to develop related element technologies and to establish regulations so that it can be applied to the domestic construction projects. As a result of pilot project about the earthwork surveying automation technology, it was confirmed that information such as terrain coordinates, soil, boring, and excavation volume is acquired smoothly. In this paper, we investigate related regulations and manuals in Japan and propose the improvement plan of domestic regulation. We plan to study regulations from early to final construction stage, combine with the 'regulation for public surveying', and improve the regulations in detail.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.2
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• pp.1-7
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• 2022

The purpose of this study is to discuss the impact of unmanned aerial vehicle service and how to activate it. The discussion on the impact of the introduction of the unmanned aerial vehicle service was examined in terms of economic, environmental, and social acceptance, and a plan to revitalize the industry was presented. In terms of economic impact, if transportation services are increased using unmanned aerial vehicles in the future, road-based transportation cargo may decrease and road movement speed may increase due to reduced road congestion. This can have a positive effect on the increase in the value of land or real estate assets, and it also provides an impact on smart city design. In terms of environmental impact, unmanned aerial vehicles (UAVs) generally move through electricity, so they emit less exhaust gas compared to other existing devices, such as vehicles and railroads, and thus have less environmental impact. However, noise can have a negative impact on the habitat in the presence of wild animals along their migration routes. In terms of social acceptability of unmanned aerial vehicles (UAV) technology, areas that are declining due to the emergence of new services may appear, and at the same time, organizations that create profits may appear, causing conflicts between industries. Therefore, it is essential to form a social consensus on the acceptance of emerging industries. The government should come up with various countermeasures to minimize the negative impact that reflects the characteristics of the unmanned aerial vehicle use service. Just as various systems such as road signs were introduced so that vehicles can be operated on the ground to secure air routes in the mid- to long-term for revitalization of unmanned-based industries, development and establishment of services that should be introduced and applied prior to constructing air routes I need this. In addition, the design and implementation of information collection and operation plans for unmanned air traffic management in Korea and a plan to secure a control system for each region should also be made. This study can contribute to providing ideas for mid- to long-term research on new areas with the development of the unmanned aerial vehicle industry.

• Journal of Digital Contents Society
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• v.19 no.3
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• pp.561-567
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• 2018

In this paper, we apply this method to the entire process of smart disaster safety management based on the $4^{th}$ industrial revolution to minimize human, social, economic and environment damage from accidents and disasters, prevention evaluation and disaster information collection analysis and real-time detection of field situation. Prevention of $5^{th}$ generation communication system by analysis, contrast by education and training using virtual reality and augmented reality disaster safety management decision support system intelligent robot for recovery, disaster, discovery, reconnaissance relief, and scale analysis of damages were proposed.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.13 no.2
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• pp.14-26
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• 2005

A tilt-rotor aircraft has various flight modes : helicopter, airplane, and conversion. Each of flight mode has unique and nonlinear flight characteristics. Therefore the gain schedules for whole flight envelope are required for effective flight performance. This paper proposes collective, flap, and nacelle angle scheduler for whole flight envelope of the Smart UAV(Unmanned Air Vehicle) based on CAMRAD(Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics) II analysis results. The scheduler designs are improved so that the pitch attitude angle of helicopter mode was minimized. The range of scheduler are reduced inside of engine performance limits. The conversion corridor and rotor governor are suggested also.