• 한국측량학회지
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• 제19권2호
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• pp.109-115
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• 2001

최근 수치사진측량시스템의 도입으로 수치정사영상의 활용도가 높아지고 있으며, 이에 따라 수치정사영상으로부터 지형지물의 반자동 또는 자동 추출에 관한 연구가 대두되고 있지만, 최근 많은 연구보고서에 의하면 흑백항공사진에서의 지형지물을 판단하거나 속성인식에 한계가 있음을 알 수 있다. 본 연구에서는 천연색 항공사진 영상을 흑백항공사진 영상과 비교, 분석하여 천연색 항공사진 영상의 특성을 분석하였으며, 반자동으로 지형요소를 추출하는 알고리즘을 개발하였고, 추출한 지형요소를 국립지리원에서 제작하는 1:5,000 수치지형도와 비교하여 반자동으로 추출가능한 지형요소를 분석하였다. 이러한 결과를 토대로 천연색 항공사진영상을 이용한 지형요소 추출 가능성과 지형요소 추출시 문제점을 분석하였고, 향후 연구에 대한 방안을 제시하였다.

• 한국측량학회지
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• 제38권5호
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• pp.443-453
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• 2020

The automatic land category extraction method was proposed, and the accuracy was evaluated by learning the aerial photo characteristics by land category in the border area with various restrictions on the acquisition of geospatial data. As experimental data, this study used four years' worth of published aerial photos as well as serial cadastral maps from the same time period. In evaluating the results of land category extraction by learning features from different temporal and spatial ranges of aerial photos, it was found that land category extraction accuracy improved as the temporal and spatial ranges increased. Moreover, the greater the diversity and quantity of provided learning images, the less the results were affected by the quality of images at a specific time to be extracted, thus generally demonstrating accurate and practical land category feature extraction.

• 한국군사과학기술학회지
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• 제15권2호
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• pp.169-176
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• 2012

GPS(Global Positioning System) is widely used for the position estimation of an aerial vehicle. However, GPS may not be available due to hostile jamming or strategic reasons. A vision-based position estimation method can be effective if GPS does not work properly. In mountainous areas without any man-made landmark, a horizon is a good feature for estimating the position of an aerial vehicle. In this paper, we present a new method to estimate the position of the aerial vehicle equipped with a forward-looking infrared camera. It is assumed that INS(Inertial Navigation System) provides the attitudes of an aerial vehicle and a camera. The horizon extracted from an infrared image is compared with horizon models generated from DEM(Digital Elevation Map). Because of a narrow field of view of the camera, two images with a different camera view are utilized to estimate a position. The algorithm is tested using real infrared images acquired on the ground. The experimental results show that the method can be used for estimating the position of an aerial vehicle.

• 대한원격탐사학회지
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• 제19권3호
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• pp.255-261
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• 2003

Recently, the enormous increase in the volume of remotely sensed data is being acquired by an ever-growing number of earth observation satellites. The combining of diversely sourced imagery together is an important requirement in many applications such as data fusion, city modeling and object recognition. Aerial triangulation is a procedure to reconstruct object space from imagery. However, since the different kinds of imagery have their own sensor model, characteristics, and resolution, the previous approach in aerial triangulation (or georeferencing) is purformed on a sensor model separately. This study evaluated the advantages of aerial triangulation of large number of images from multi-sensors simultaneously. The incorporated multi-sensors are frame, push broom, and whisky broom cameras. The limits and problems of push-broom or whisky broom sensor models can be compensated by combined triangulation with other sensors The reconstructed object space from multi-sensor triangulation is more accurate than that from a single model. Experiments conducted in this study show the more accurately reconstructed object space from multi-sensor triangulation.

• 아시안잔디학회지
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• 제7권2_3호
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• pp.129-135
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• 1993

Surface soils and aerial parts of Korean lawn(Zoysia koreana) at normal fair way of 4 golf courses and yellow discolored fairway of one golf course in Kyonggi province were taken at and analyzed for mineral contents in soil Mg and Ca were most deficient while EC was too high and phosphorus was exess. There were significant positive correlation between pH and Ca and between EC and total N. There was no consistent simple correlation between single component in soil and plant, indicating the involvement of multi-minerals in one mineral absorption. m mineral contents of aerial part Mg was severely low. potassium moderately but Ca was normal, Mg and Ca showed significant correlation in aerial part, yellow-discolored lawn showed the lowest content of Mg in aerial part and surface soil. Very high N and high phosphorus in aerial part inspite of low P in soil. The above facts indicates Mg deficiency in fair way soils in most golf courses resulting in yellow-discoloration in lawn.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.883-890
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• 2021

In this study, joint analysis was conducted on the rock slope by aerial surveying using UAV. Aerial photos were taken using UAV to measure the directionality of the rock slope exposed to the site, and the directionality of the joint was analyzed using the photographed photos. UAV photography was taken under conditions of 90% overlap and an altitude of 50m. The photographing path was measured in the horizontal, vertical, and oblique directions based on the slope, and the joint characteristics were analyzed. Aerial surveying research on the joint directionality analysis of rock slopes is still incomplete, and the method for accurate joint directionality analysis is not presented strategically, so it is difficult to apply it in design. Through the results of this study, we would like to propose an flight photographing technique for the investigation of rock joints. As a result of the study, in the case of the joint investigation of the rock slope using UAV, it was necessary to change conditions such as altitude, aerial photography route, and overlap according to the size of the joint according to the site conditions.

• 한국멀티미디어학회논문지
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• 제25권2호
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• pp.237-246
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• 2022

Among the technologies of the 4th industrial revolution, drones that have grown rapidly and are being used in various industries can be operated by the pilot directly or can be operated automatically through programming. In order to be controlled by a pilot or to operate automatically, it is essential to predict and analyze the optimal path for the drone to move without obstacles. In this paper, after securing and analyzing the pilot training dataset through the unmanned aerial vehicle piloting training platform designed through prior research, the profile of the dataset that should be preceded to search and derive the optimal route of the unmanned aerial vehicle was designed. The drone pilot training data includes the speed, movement distance, and angle of the drone, and the data set is visualized to unify the properties showing the same pattern into one and preprocess the properties showing the outliers. It is expected that the proposed big data-based profile can be used to predict and analyze the optimal movement path of an unmanned aerial vehicle.

• 한국항공운항학회지
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• 제30권4호
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• pp.57-64
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• 2022

A study on propllers for unmaned aerial vehicles is conducted using the open softwares. Since the shape of the propeller is closely related to the thurst characteristics of the propulsion system, adopting an appropriate propeller will significantly reflect stable aerodynamic performances. In this study, propellers for unmanned aerial vehicles were modeled by using OpenVSP and Propel for comparison, the thrust characteristics according to the number of blades and the diameter of the propeller were analyzed. In addition, the tendency of thrust characteristics according to various propeller pitch angles was confirmed. Based on the analysis results of this study, the applicability of the propeller shape to the design of the unmanned aerial vehicle was confirmed. It is shownthat the analysis results of this study can be utilized when modeling the propeller shape in research such as a conceptual design of unmanned aerial vehicle. In this case, it should be noted that OpenVSP does not involve the viscous effect of air.

• 항공우주시스템공학회지
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• 제17권6호
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• pp.133-143
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• 2023

본 논문에서는 유무인 협업을 위한 유인회전익기에 의한 다수 무인기 운용통제기술의 요구도 검증을 위한 통합검증환경의 요구도 분석, 구현 및 검증에 대해 기술하였다. 통합검증환경은 유인회전익기 비행 모의, 무인항공기 비행 및 임무장비 모의, 무인항공기 제어 및 유인회전익기와의 통제권 변경을 위한 지상통제장비 모의, 유인회전익기 및 무인항공기 임무계획 작성 및 전송을 위한 운용통제장비 모의로 구성된다. 각각 구현된 구성품들은 소프트웨어/하드웨어 통합시험을 통해 요구도를 검증하였다.

• Natural Product Sciences
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• 제4권1호
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• pp.45-50
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• 1998

Seven triterpenoid saponins such as oleanolic acid 28-O-{\beta}-D-glucopyranosyl$ ester, hederagenin $28-O-{\beta}-D-glucopyranosyl$ ester, chikusetsusaponin IVa, udosaponin A, salsoloside C, udosaponins F and C were isolated from the aerial parts of Aralia continentalis, among which two $28-O-{\beta}-D-glucopyranosyl$ esters of oleanolic acid and hederagenin are isolated for the first tome from this plant. These results suggested that the chemical components of Korean Dokwhal are practically identical to those of japanese Udo supporting the chemotaxonomical point of view.