• 로봇학회논문지
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• 제13권2호
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• pp.113-120
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• 2018

To fly a drone or unmanned aerial vechicle(UAV) safely, its pilot needs to maintain high situation awareness of its flight space. One of the important ways to improve the flight space awareness is to integrate both the global and the local navigation map a drone provides. However, the drone pilot often has to use the inconsistent reference frames or perspectives between the two maps. In specific, the global navigation map tends to display space information in the third-person perspective, whereas the local map tends to use the first-person perspective through the drone camera. This inconsistent perspective problem makes the pilot use mental rotation to align the different perspectives. In addition, integrating different dimensionalities (2D vs. 3D) of the two maps may aggravate the pilot's cognitive load of mental rotation. Therefore, this study aims to investigate the relation between perspective difference ($0^{\circ}$, $90^{\circ}$, $180^{\circ}$, $270^{\circ}$) and the map dimensionality matches (3D-3D vs. 3D-2D) to improve the way of integrating the two maps. The results show that the pilot's flight space awareness improves when the perspective differences are smaller and also when the dimensionalities between the two maps are matched.

• Journal of Multimedia Information System
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• 제6권1호
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• pp.23-30
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• 2019

A communications profile is a system that acquires information from communication links to an ambulance or other vehicle moving on a road and compiles a database based on this information. The equipment (six sets of HDTVs, fish-eye camera, satellite antenna with tracking system, and receiving power from the satellite beacon of the N-star) mounted on the roof of the vehicle, image data were obtained at Yokohama Japan. From these data, the polygon of the building was actually produced and has arranged on the map of the Geographical Survey Institute of a 50 m-mesh. The optical study (relationship between visibility rate and elevation angle) were performed on actual data taken by fish-eye lens, and simulated data by 3D-Map with polygons. There was no big difference. This 3D map system then predicts the communication links that will be available at a given location. For line-of-sight communication, optical analysis allows approximation if the frequency is sufficiently high. For non-line-of-sight communication, previously obtained electric power data can be used as reference information for approximation in certain cases when combined with predicted values calculated based on a 3D map. 3D maps are more effective than 2D maps for landing emergency medical helicopters on public roadways in the event of a disaster. Using advanced imaging technologies, we have produced a semi-automatic creation of a high-precision 3D map at Yokohama Yamashita Park and vicinity and assessed its effectiveness on telecommunications and ambulatory merits.

• 대한수학회보
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• 제39권3호
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• pp.389-399
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• 2002

We prove that the results of Chang, Park and Cho in ［1］ concerning the iterative approximation of asymptotically pseudocontractive maps with bounded ranges can be extended to a certain class of asymptotically pseudocontractive maps whose ranges need not be bounded.

• ETRI Journal
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• 제44권6호
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• pp.1034-1046
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• 2022

The learning-based multiview stereo (MVS) methods for three-dimensional (3D) reconstruction generally use 3D volumes for depth inference. The quality of the reconstructed depth maps and the corresponding point clouds is directly influenced by the spatial resolution of the 3D volume. Consequently, these methods produce point clouds with sparse local regions because of the lack of the memory required to encode a high volume of information. Here, we apply the atrous spatial pyramid pooling (ASPP) module in MVS methods to obtain dense feature maps with multiscale, long-range, contextual information using high receptive fields. For a given 3D volume with the same spatial resolution as that in the MVS methods, the dense feature maps from the ASPP module encoded with superior information can produce dense point clouds without a high memory footprint. Furthermore, we propose a 3D loss for training the MVS networks, which improves the predicted depth values by 24.44%. The ASPP module provides state-of-the-art qualitative results by constructing relatively dense point clouds, which improves the DTU MVS dataset benchmarks by 2.25% compared with those achieved in the previous MVS methods.

• 대한공간정보학회지
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• 제21권2호
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• pp.11-17
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• 2013

3차원 모델은 현재 많은 분야에서 사용되고 있다. 특히 기존 평면의 지도에 비해 3차원으로 제작된 지도는 현실감이 뛰어날 뿐만 아니라 제한된 평면 지도 안에서 얻을 수 없는 다양한 정보를 제공 할 수 있기 때문이다. 본 논문에서는 지금까지 모델링을 위해 사용되었던 고가의 레이저 스캐너를 대체하여 디지털 카메라 스테레오 매칭 알고리즘의 성능 개선을 통하여 쉽고 빠르게 양산 할 수 있는 프로세스를 제안하였다. 본 연구에 사용된 알고리즘은 OpenCV 라이브러리 내에 포함되어있는 SURF 알고리즘이며 알고리즘이 가지고 있는 부정합 점들을 호모그라피 변환과 에피폴라 라인을 이용하여 제거하였다. 또한 개선된 알고리즘을 상용프로그램과 비교하였으며 상용프로그램에 비하여 성능이 우수한 것으로 확인하였다. 제안된 방법은 스테레오 매칭의 조건을 만족한다면 쉽고 빠르게 3차원 모델링을 할 수 있기 때문에 각종 디지털 지도나 3차원 가상 현실 분야에 크게 기여할 것으로 예상된다.

• 한국측량학회지
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• 제25권3호
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• pp.239-247
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• 2007

3차원 공간정보구축 사업은 현재 다양하게 진행되고 있으며, 많은 분야에 걸쳐 활용되고 있지만, 3차원 국가기본도로서의 역할을 할 수 있는 3차원 수치지도에 관한 연구는 미비한 실정이다. 따라서 본 연구에서는 기존 2차원 수치지도 제작의 원시자료인 도화원도의 문제점을 분석하고, 3차원 수치지도 제작을 위한 도화원도의 수정 및 활용방안을 제시하였으며, 도화원도, 수치지도, DEM, 항공영상 등의 2차원 벡터 및 래스터 자료로부터 3차원 수치지도를 제작 및 편집할 수 있는 3차원 수치지도 편집 시스템을 개발하는데 그 목적이 있다. 본 시스템은 ISO/TC211과 OGC의 표준안인 기하 및 속성객체의 자료구조를 수용하여 설계하였으며, 입체시 기반의 3차원 입체(stereo 3D) 편집기능, 투영 기반의 3차원 뷰(2.5D) 편집 기능 및 3차원 공간연산자에 대해 설계 구현 하였다. 또한 본 연구에서 개발된 3차원 수치지도 편집시스템을 활용하여 기존에 제작된 도화원도를 이용한 3차원 수치지도의 제작과 기존 도화원도를 수정 편집하여 3차원 수치지도를 제작하였으며, 각각의 적용 결과에 대하여 비교 분석하였다.

• 충청수학회지
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• 제18권1호
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• pp.51-64
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• 2005

The object of this paper is to prove two unique common fixed point theorems for a pair of a set-valued map and a self map satisfying a general contractive condition using orbital concept and weak-compatibility of the pair. One of these results generalizes substantially, the result of Dhage, Jennifer and Kang [4]. Simultaneously, its implications for two maps and one map improves and generalizes the results of Dhage [3], and Rhoades [11]. All the results of this paper are new.

• 충청수학회지
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• 제7권1호
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• pp.25-32
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• 1994

Let A be a (complex) Banach algebra. The object of the this paper shall be remove the continuity of the derivation in the recently theorems. We prove that every derivation D on A satisfying [D(a), a] ${\in}$ Prad(A) for all a ${\in}$ A maps into the radical of A. Also if ${\alpha}D^3+D^2$ is a derivation for some ${\alpha}{\in}C$ and all minimal prime ideals are closed, then D maps into its radical.

• Journal of Forest and Environmental Science
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• 제30권3호
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• pp.253-258
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• 2014

The study attempts to assess the status, distribution, conservation and use value of Medicinal and Aromatic Plant (MAPs) in the Sagarmatha National Park. Altogether 62 species of MAPs belonging to 47 genera and 33 families have been recorded in the study area. 10 species, belonging to 9 families are categorized as the potential species. Out of the these species, most potential in local but threatened species are Allium hypsistum Stearn, Cordyceps sinensis Sacc, Dactylorhiza hatagirea Soo, Nardostachys grandiflora DC, Aconitum orochryseum, Ephedra gerardiana Wall. Ex. Stapf, Swertia multicaulis D. Don, Picrorhiza scrophulariflora Penne, Rheum australe. D. Don, Malva verticillataL and Swertia pedicallata Benerji. By analysis of data using Simpson's diversity index (SI) and Shannon weaver function (H'), there was high diversity (more heterogeneous) MAPs species composition in the Manjo Gate to Large Dobhan. (0.98349). Less diversity (less heterogeneous) MAPs species composition was in Tyanboche to Pangoche (0.90419). Similarly, the Shannon weaver function shows that in plots laying out in Mongla to Phorche are evenly distributed than others However, higher MAPs species (i.e., 31) was found in the way of Manjo Gate to Larja Dobhan than others.

• 한국측량학회지
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• 제36권3호
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• pp.117-126
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• 2018

Due to intelligent transport systems, location-based applications, and augmented reality, demand for image maps and 3D (Three-Dimensional) maps is increasing. As a result, data acquisition using UAV (Unmanned Aerial Vehicles) has flourished in recent years. However, even though orthophoto map production and research using UAVs are flourishing, few studies on 3D modeling have been conducted. In this study, orthophoto and 3D modeling research was performed using various angle images acquired by a UAV. For orthophotos, accuracy was evaluated using a GPS (Global Positioning System) survey that employed VRS (Virtual Reference Station) acquired checkpoints. 3D modeling was evaluated by calculating the RMSE (Root Mean Square Error) of the difference between the outline height values of buildings obtained from the GPS survey to the corresponding 3D modeling height values. The orthophotos satisfied the acceptable accuracy of NGII (National Geographic Information Institute) for a 1/500 scale map from all angles. In the case of 3D modeling, models based on images taken at 45 degrees revealed better accuracy of building outlines than models based on images taken at 30, 60, or 75 degrees. To summarize, it was shown that for orthophotos, the accuracy for 1/500 maps was satisfied at all angles; for 3D modeling, images taken at 45 degrees produced the most accurate models.