• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.591-594
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• 2004

항공기 정비는 고도의 기술과 많은 노력, 시간을 필요로 한다. 첨단화 되어가는 항공무기체계에 따라 정비작업도 고도화되어 가면서 시간과 작업량이 늘어나게 되고 정비사 부족 문제를 않고 있는 현시점에서는 업무량은 과중되어 질 수 밖에 없다. 하지만 현재 공군에서는 보다 체계적이고 효율적인 정비사들의 업무 할당에 대한 시스템이나 절차가 없었다. 본 연구는 항공기의 비행스케줄에 따른 정비사들의 정비 시간을 균등히 할당함으로써 업무의 효율을 높이고 향후 정비사들의 스케줄 관리를 위한 지침을 제공하는데 그 목적이 있다. 현재 공군에 있는 실질적인 자료를 가지고 실험을 하여 입력 자료에 대한 현실성을 보다 높였으며, 수학적 모델링을 통하여 구축된 스프레드시트 모형을 가지고 인원할당과 근무시간 할당을 위한 최적의 시스템을 palisade사의 evolver를 사용하여 구축하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.2
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• pp.281-290
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• 2022

In Korea, the number of national facilities for which a safety inspection is mandatory is increasing, and a safer safety inspection method is needed. This study aimed to increase the efficiency of the bridge safety inspection by enabling rapid exterior inspection while securing the safety of inspectors by using drones to perform the safety inspections of bridges, which had mainly relied on visual inspections. For the research, the Youngjong Grand Bridge in Incheon was selected as a test bed and was divided into four parts: the warren truss, suspension bridge main cable, main tower, and pier. It was possible to establish a five-step standard procedure for drone safety inspections. The step-by-step contents of the standard procedure obtained as a result of this research are: Step 1, facility information collection and analysis, Step 2, analysis of vulnerable parts and drone flight planning, Step 3, drone photography and data processing, Step 4, condition evaluation by external inspection, Step 5, building of external inspection diagram and database. Therefore, if the safety inspections of civil engineering facilities including bridges are performed according to this standard procedure, it is expected that these inspection can be carried out more systematically and efficiently.

• Journal of the military operations research society of Korea
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• v.37 no.1
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• pp.119-128
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• 2011

This paper deals with a study on mission analysis considering the effectiveness measurement of UAV system operations. This mission analysis process is composed of 5 steps; (1) creation of a base model in MANA, (2) design of input parameter set using experiment design, (3) mapping input parameter set to the MANA scenario file, (4) data farming and model run in batch process, and (5) statistical analysis of the simulation result. In the result of this study, the effect of input parameter to the dependent parameter was shown to decrease in the order classification range, sweep width, height, speed, FOV(Field of view), and classification probability. The study also shows that the operational effectiveness of an improved scenario proposed can increase 10.2% from the base scenario.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.1
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• pp.59-67
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• 2002

Recently, much demand of vector data have increased rapidly such as a digital map instead of traditional a paper map and the raster data such as a high-resolution orthoimage have been used for many GIS application with the advent of industrial high-resolution satellites and development of aerial optical sensor technologies. Aerial photogrammetric technologies using an airship can offer cost-effective and high-resolution color images as well as real time images, different from conventional remote sensing measurements. Also, it can acquire images easily and its processing procedure is short and simple relatively. On the other hand, it has often been used for the production of a small-scale land use map not required high accuracy, monitoring of linear infrastructure features through mosaicking strip images and construction of GIS data. Through this study, the developed aerial photogrammetric system using the airship expects to be applied to not only producing of scale 1:5, 000 digital map but also verifying, editing, and updating the digital map which was need to be reproduced. Further more, providing the various type of video-images, it expects to use many other GIS applications such as facilities management, scenery management and construction of GIS data for Urban area.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.10
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• pp.1017-1026
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• 2009

The solar cell system operates by facing the sun-light. Minor cracks, static discharge, and thermal shock that can happen during production/testing phase can lead to degradation in performance during operation, since solar cells are exposed to extreme thermal/mechanical environment in space. In order to detect small cracks and internal damages in the solar cells due to thermal shocks, which are the core units of a solar cell system, expensive equipment, complicated test process, and much time are required. Therefore, a qualitative method for easily and quickly testing the 'health' of solar cell functionality is required. This dissertation describes a theoretical and technical grounds for quickly and easily evaluating the health of solar cells using electroluminescence effect of Gallium-Arsenide solar cells that are most widely used by spacecrafts in recent years. Also described in the dissertation is the technical issues and constraining factors for applying the proposed method to actual space-rated solar cell systems.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.4
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• pp.287-294
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• 2007

A static aeroelastic analysis for supersonic aircraft wing equipped with external store under the wing lower surface is performed using computational fluid dynamics (CFD) and computational structural technology(CST) coupling methodology. Two mapping algorithms, which are the pressure mapping algorithm and the displacement mapping algorithm, are used for CFD/CST coupling. A three-dimensional unstructured Euler code and finite element analysis program are used to calculate the flow properties and the structural displacements, respectively. The coupling procedure is repeated in an iterative manner until a specified convergence criterion is satisfied. Static aeroelastic analysis for a typical supersonic flight wing is performed and final converged wing configuration is obtained after several iterations.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.35.3-35.3
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• 2010

항공용 지역위성항법 보강시스템(Ground Based Augmentation System, GBAS)은 지상에서 위성항법시스템에 대한 위치보정정보와 무결성 정보를 생성 및 제공하여 공항 주변 항공기의 정밀 이착륙을 돕는 지상기반의 시스템이다. 이 시스템은 기본적으로 위성항법신호를 사용하기 때문에 전리층 영향을 받게 되는데 특히 전리층 폭풍(Ionospheric storm)의 경우 공간적으로 급격한 위치오차 차이를 발생시키기 때문에 안정적인 항공기의 정밀이착륙을 위해서는 전리층 폭풍의 영향을 최소화 하는 것이 중요하다. 이를 위하여 현재 항공용 지역위성항법 보강시스템의 지상시스템(Ground Facility)과 항공기 탑재시스템에서의 전리층 폭풍에 대한 정확한 감시와 전리층 폭풍의 지배적 영향을 받는 위상항법신호를 제거하거나 보완하는 방식 등 전리층 폭풍의 영향을 최소화하기 위한 기법들이 계속해서 연구 중이다. 이 논문에서는 2001년과 2003년 미국에서 발생한 전리층 폭풍에 대한 위성항법데이터 분석 결과와 기존의 연구결과를 기반으로 전리층 폭풍에 대한 모델링과 지상시스템과 항공기 간의 공간적 상이현상(Spacial decorrelation)을 고려하여 전리층 폭풍이 항공기 이착륙에 미치는 영향에 대한 분석 결과를 제시한다. 전리층 폭풍에 대한 수학적 모델링을 하기 위해서는 전리층 폭풍의 물리적 특성에 대한 이해와 전리층 폭풍 발생 시 획득한 위성항법 데이터를 이용한 통계학적 분석이 선행되며 이러한 분석결과와 항공기 이착륙에 절차를 반영하여 항공기에 미치는 영향 분석을 위한 수학적 모델을 완성하였다. 완성된 모델을 국내 공항에서 실제 비행시험을 통하여 획득한 위성항법데이터에 적용하여 전리층 폭풍이 국내 공항에서 항공기 이착륙에 어떠한 영향을 미치는지를 분석하였다. 또한, 대표적 전리층 폭풍 감지기법 중 하나인 Code-Carrier Divergence Test 알고리즘을 적용한 결과도 함께 제시하였다. 이 논문의 결과는 항공용 지역위성항법 보강시스템에 대한 전리층 폭풍의 영향을 최소화하기 위한 기법 연구의 기반이 되며 시스템의 성능평가를 위한 다양한 시뮬레이션환경의 하나로서도 활용이 가능할 것이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.239-242
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• 2016

In recent years, Unmanned Aerial Vehicles (UAV) have been developed for both military and civilian activities in regions where the presence of onboard human pilots is risky or not necessary. However, UAV require a high demand of power to achieve its missions such as taking images/videos in a certain area or surveillance activities. Therefore, this situation triggers the need of techniques to reduce power consumption for UAV to complete its mission safely. One of the methods is to use a waypoint optimization procedure which deals with a pre-specified set of waypoints to find a minimum route to fly through those waypoints in order to reduce power consumption. In this paper, due to the UAV's multidisciplinary which makes it impossible to be represented as an analytical model, we design a simulation model of UAV using MATLAB Simulink and AeroSim Blockset, an analysis package in aerospace industry. The simulation model is then coupled with optimization algorithms along with a set of waypoints (flight path) in order to measure at which percentage power consumption can be minimized for UAV.

• Convergence Security Journal
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• v.18 no.3
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• pp.133-140
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• 2018

As the core technology of the 4th Industrial Revolution is applied to drone, the potential for growth in the field of unmanned aerial vehicles is very large, and the utilization of civilian & military fields in the domestic & foreign is increasing rapidly. Because application areas of drone in the civilian field is various, it is excellent in terms of cost effectiveness and high value in utilization when it is used for military operation support mission. Especially, in the case of the Air Force, it is expected that military usage effectiveness will be high if drone replaces various air operations support missions such as aircraft inspection, supply of military supplies, base security. We find out the missions that can utilize drones for military operations support and propose the recommendation and data management plan accordingly. We recommend the most suitable drones and equipment that perform similar missions in the private sector and propose the data modeling of relational database.

• Journal of Advanced Navigation Technology
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• v.23 no.1
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• pp.8-19
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• 2019

Pilots have used checklist as a valuable tool to improve aviation safety and to reduce human error. A checklist however is too complex for a student pilot to use with less flight experience or time than a commercial pilot. It is agreed upon such complex checklist be a factor to threaten aviation safety for student pilots. This paper has focused on a checklist by dividing it into a couple of basic three flight procedures. Making exploratory case study of student pilots, researchers could analyze the correlation between checklist factors and those of human errors. First of all, it was necessary for student pilots to be educated professional knowledge regarding aircraft structures and engines to perform preflight inspection reducing human errors. Moreover it was recommended student pilots as well as maintenance crew confirm checklist together to enhance aviation safety.