• 한국항공운항학회:학술대회논문집
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• 2006.11a
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• pp.153-158
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• 2006

• 한국항공운항학회:학술대회논문집
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• 2007.06a
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• pp.18-24
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• 2007

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.202-205
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• 2008

건물이 밀집된 도심지역을 촬영한 두 시기 항공영상에 화소기반 변화탐지 기법인 영상대차(Image Differencing), 영상중첩 분석(Image Overlay)기법을 적용하여 넓은 대도심지역의 효율적인 변화탐지 가능성을 살펴보았다. 영상대차(Image Differencing) 기법은 알고리즘이 간단하고 정량적인 분석이 가능한 결과를 얻을 수 있다는 장점이 있으나 고층건물밀집지역을 보여주고 있는 고해상도 항공영상의 적용과정에서는 폐색영역, 그림자 등으로 인해 정확한 변화탐지 결과를 보여주지 못했다. 영상중첩 분석(Image Overlay)기법은 한 번에 두 개 또는 세 개의 영상을 비교 분석할 수 있다는 장점이 있으나 직관적인 분석만을 제공하고 정량적인 분석이 불가능하였다. 현재의 화소기반 영상변화탐지 기술수준으로는 고해상도 공간영상에 대한 신뢰도 높은 변화탐지 분석결과를 얻을 수 없다는 것을 확인하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.21-24
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• 2021

본 논문에서는 딥러닝을 기반으로 하는 야간 점멸신호 제어를 통하여 신호 위반과 과속에 의한 교통사고로부터 보행자와 운전자의 인명피해 최소화를 목표로 한다. 제안된 기법은 딥러닝을 기반으로 하여 교차로에서 심야 보행자 인식률을 향상시키고, 야간 점멸신호를 연동 제어하는 기법을 제안하고 있다. 야간의 영상 인식 과정은 어두운 제약조건의 환경에서 떨어지는 영상인식을 보완하기 위하여 PIR 센서로부터 물체를 인식한다. 아두이노의 PIR 센서에서 인식된 물체에 대하여 보행자 여부를 판단하기 위하여 YOLO 알고리즘을 적용한다. 젯슨자비에NX로부터 수신받은 정보를 기반으로 점멸신호에서 일반 신호등 신호로 전환 후 보행자 횡단 시간을 고려하여 일정 시간이 지난 후 다시 일반 신호등 신호에서 점멸신호로 전환한다. 본 논문은 심야의 제한된 조건에서 보행자 식별을 통하여 교차로에서 보행자와 운전자의 인명피해 줄일 수 있을 것으로 기대한다.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.213-221
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• 2007

This paper showed how to analysis the object-based classification for wildfire fuel type map using Hyperion hyperspectral remote sensing data acquired in April, 2002 and compared the results of the object-based classification with the results of the pixel-based classification. Our methodological approach for wildfire fuel type map firstly processed correcting abnormal pixels and atypical bands and also calibrating atmospheric noise for enhanced image quality. Fuel type map is characterized by the results of the spectral mixture analysis(SMA). Object-based approach was based on segment-based endmember selection, while pixel-based method used standard SMA. To validate and compare, we used true-color high resolution orthoimagery.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.10
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• pp.1873-1878
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• 2017

Recently, many researches have been conducted on the aviation industry to replace the wire harness cable between the avionics of the aircraft with the wireless network. In this paper, we present an Event-Based Simulator for Wireless Avionics Intra-Communications (ES-WAIC) that can verify core technologies of wireless networks and efficiently integrate different layers of the network. ES-WAIC is developed to enhance the readability between the real time control application developers of the higher layer and the network layer developers. Specifically, the practical implement relies on an event-based programming concept to increase portability and compatibility that can be applied to the realistic low-power wireless embedded networks. ES-WAIC implements the overall system layers including the wireless channel modeling of the 4.4GHz band, the physical layer, the medium access control, the network, and the application layer of wireless avionics intra-communications.

• Journal of Advanced Navigation Technology
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• v.27 no.2
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• pp.182-189
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• 2023

Depth estimation is a key technology in 3D map generation for autonomous driving of vehicles, robots, and drones. The existing sensor-based method has high accuracy but is expensive and has low resolution, while the camera-based method is more affordable with higher resolution. In this study, we propose self-attention-based unsupervised monocular depth estimation for UAV camera system. Self-Attention operation is applied to the network to improve the global feature extraction performance. In addition, we reduce the weight size of the self-attention operation for a low computational amount. The estimated depth and camera pose are transformed into point cloud. The point cloud is mapped into 3D map using the occupancy grid of Octree structure. The proposed network is evaluated using synthesized images and depth sequences from the Mid-Air dataset. Our network demonstrates a 7.69% reduction in error compared to prior studies.

• Journal of Aerospace System Engineering
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• v.17 no.6
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• pp.46-53
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• 2023

As urban traffic congestion and environmental pollution are becoming significant issues in major cities, Urban Air Mobility (UAM) is gaining attention as an efficient solution. In this study, we conducted a geographic information system (GIS)-based spatial analysis and clustering algorithm considering the actual data of the terrain and infrastructure in the Busan area, through which we were able to select the location of vertiports and corridors (flight routes) for the UAM operation. Based on the Gimhae International Airport, which is expected to be the center of the UAM infrastructure system in the Busan region, we judged that three vertiport locations in the target area were suitable. Subsequently, we used the A^* (A-star) algorithm considering Ground Risk to select a flight path that minimized both risk and distance. Through this, we confirmed a risk reduction effect of 80.168% compared to the minimum distance route.

• Journal of Aerospace System Engineering
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• v.18 no.2
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• pp.12-20
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• 2024

The application of reinforcement design to ensure the structural safety of electronics in small satellites is limited by the spatial constraints of the satellite structure during launch vibrations. Additionally, a reliable evaluation approach is needed for mounting highly integrated devices that are susceptible to fatigue failure. Although the Steinberg fatigue failure theory has been used to assess the structural integrity of electronic devices, recent studies have highlighted its theoretical limitations. In this paper, we propose a structural methodology based on the critical strain theory to design the digital control unit (DCU) of the X-band SAR payload component for the small SAR technology experimental project (S-STEP), a small satellite constellation. To validate the design, we conducted modal and random analyses using simplified modeling techniques. Based on our methodology, we ultimately demonstrated the structural safety of the electronics through analysis results, safety margin derivation, and functional tests conducted both before and after the launch test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3B
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• pp.474-484
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• 2010

In this paper, we introduce a RFIDbased real time air cargo monitoring system for cargo management in the air cargo terminal. In order to construct functional requirement and development framework,. we have analyzed the user requirements of cargo personnel of Incheon International Air Cargo Terminal. To find out the possibilities to adopt RFID in the cargo, we had benchmarked different RFID systems and also tested radio environment of the cargo. Based on the RFID system test and radior environment test, we developed a web based cargo monitoring solution which adopts EPC network and BPM solution with flexibility and expandability.