• Journal of Astronomy and Space Sciences
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• 제29권3호
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• pp.305-313
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• 2012

We conducted thermal analyses and cooling tests of the space observation camera (SOC) of the multi-purpose infrared imaging system (MIRIS) to verify passive cooling. The thermal analyses were conducted with NX 7.0 TMG for two cases of attitude of the MIRIS: for the worst hot case and normal case. Through the thermal analyses of the flight model, it was found that even in the worst case the telescope could be cooled to less than $206^{\circ}K$. This is similar to the results of the passive cooling test (${\sim}200.2^{\circ}K$). For the normal attitude case of the analysis, on the other hand, the SOC telescope was cooled to about $160^{\circ}K$ in 10 days. Based on the results of these analyses and the test, it was determined that the telescope of the MIRIS SOC could be successfully cooled to below $200^{\circ}K$ with passive cooling. The SOC is, therefore, expected to have optimal performance under cooled conditions in orbit.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.667-668
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• 2015

While the plant projects grow bigger and global attention to the plant is increasing, efficient space arrangement is not working in plant project because of the complex structure in installing the equipment unlike the construction project. In addition to this, presently, problem in installation process caused by the disagreement between floor plan and real spot is rising. Therefore the target of this research is to solve the problems and reaction differences, caused by changing the space arrangement in installing the equipment of plant construction. And this research suggests the equipment arrangement method for construction and related processes. To solve the problem, 3D cloud point data of space and equipment is collected by 3D laser scanning and the space matching is operated. In processing the space matching, data is simplified by applying the octree algorithm. This research simplifies the 3D configuration data acquired by 3D scanner equipment through the octree algorithm, and by comparing this data, identifies the space for target equipment, and finally suggests the algorithm that makes the auto space arrangement of equipment possible in construction site and also suggests the process to actualize this algorithm.

• Investigative Magnetic Resonance Imaging
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• 제22권4호
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• pp.229-239
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• 2018

Purpose: To assess the diagnostic performance in detecting rotator cuff tears at 3T of non-arthrographic shoulder magnetic resonance imaging (MRI) using 3D isotropic turbo spin-echo (TSE-SPACE) sequence as compared with 2D sequences. Materials and Methods: Seventy-four patients who were arthroscopically confirmed to have underwent non-arthrographic shoulder MRI with 2D sequences and TSE-SPACE were included. Three independent readers retrospectively scored supraspinatus and infraspinatus tendon (SST-IST) and subscapularis tendon (SCT) tears on 2D sequences and TSE-SPACE. Results: The mean sensitivity, specificity, and accuracy of the three readers were 95%, 100%, and 95% on TSE-SPACE and 99%, 93%, and 98% on 2D sequences for detecting SST-IST tears, respectively, whereas those were 87%, 49%, and 68% on TSESPACE and 88%, 66%, and 77% on 2D sequences for detecting SCT tears, respectively. There was no statistical difference between the two sequences, except for in the specificity of one reader for detecting SCT tears. The mean AUCs of the three readers on TSE-SPACE and 2D sequences were 0.96 and 0.98 for detecting SST-IST tears, respectively, which were not significantly different, while those were 0.71 and 0.82 for detecting SCT tears, respectively, which were significantly different (P < 0.05). Conclusion: TSE-SPACE may have accuracy and reliability comparable to conventional 2D sequences for SST-IST tears at non-arthrographic 3T shoulder MRI, whereas TSE-SPACE was less reliable than conventional 2D sequences for detecting SCT tears.

• 한국통신학회논문지
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• 제35권1B호
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• pp.35-41
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• 2010

본 논문에서는 컴퓨터를 사용한 효과적 정보전달을 위해 2D 영상정보를 3D 가상공간에 배치하고 음성 정보와의 유기적 연결기능을 갖는 3D 뷰 설계를 제안한다. 3D 공간에 배치된 영상정보의 사용자 접속을 어느 시점 또는 어떤 각도에서도 가능하도록 하여, 시각정보 전달효과를 제고하고 있으며, 음성정보의 첨부가 용이하도록 설계하였다. 3D공간에서의 영상 및 음성정보 배치는 단순하지만 효과적인 접속기능을 포함하고 있으며, 이들의 탐색 및 시청을 사용자접속 관점에서 설계하여 정보전달 효과를 제고하였다.

• 로봇학회논문지
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• 제18권3호
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• pp.337-345
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• 2023

In this paper, we propose a 3D LiDAR sensor-based costmap generation and path planning algorithm using it for reliable autonomous flight in complex indoor environments. 3D path planning is essential for reliable operation of UAVs. However, existing grid search-based or random sampling-based path planning algorithms in 3D space require a large amount of computation, and UAVs with weight constraints require reliable path planning results in real time. To solve this problem, we propose a method that divides a 3D space into several 2D spaces and a path planning algorithm that considers the distance to obstacles within each space. Among the paths generated in each space, the final path (Best path) that the UAV will follow is determined through the proposed objective function, and for this purpose, we consider the rotation angle of the 2D space, the path length, and the previous best path information. The proposed methods have been verified through autonomous flight of UAVs in real environments, and shows reliable obstacle avoidance performance in various complex environments.

• 한국콘텐츠학회논문지
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• 제14권7호
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• pp.1-9
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• 2014

2D 영상 콘텐츠 시퀀스로부터 입체 3D 영상을 생성하는 기존의 2D-3D 변환(conversion) 방법은 제작파이프라인 상에서 많은 수작업이 요구된다. 본 논문에서는 기존 변환 방식의 문제점을 해결하기 위해 대상 장면의 공간을 재구성하는 효율적인 2D-3D 변환 방법을 제안한다. 제안된 방법은 영상 시퀀스를 입체적으로 분석하여 3차원 공간모델을 구성하고 텍스처 재사영 방법을 통해 스테레오 영상을 생성한다. 해석된 장면의 구조 정보를 이용하여 정확한 3D 입체 콘텐츠를 제작할 수 있음을 확인하였다. 제안된 시스템을 이용하여 스테레오그래퍼(stereographer)와 영상 제작자가 2D-3D 입체변환을 효율적으로 진행할 수 있다.

• 한국멀티미디어학회논문지
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• 제24권11호
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• pp.1518-1525
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• 2021

Due to the growth of VR industry and rise of digital twin industry, the importance of implementing 3D data same as real space is increasing. However, the fact that it requires expertise personnel and huge amount of time is a problem. In this paper, we propose a system that generates point cloud data with same shape and color as a real space, just by scanning the space. The proposed system integrates 3D geometric information from lidar and color information from stereo camera into one point cloud. Since the number of 3D points generated by lidar is not enough to express a real space with good quality, some of the pixels of 2D image generated by camera are mapped to the correct 3D coordinate to increase the number of points. Additionally, to minimize the capacity, overlapping points are filtered out so that only one point exists in the same 3D coordinates. Finally, 6DoF pose information generated from lidar point cloud is replaced with the one generated from camera image to position the points to a more accurate place. Experimental results show that the proposed system easily and quickly generates point clouds very similar to the scanned space.

• 한국멀티미디어학회논문지
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• 제24권5호
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• pp.629-641
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• 2021

Crowd behavior simulations have been studied to further accelerated and refined by parallelism by inducing agent-interacting forces into the image field representing the forces of attraction and repulsion. However, it was difficult to consider rapidly changing environments such as fire situations in buildings because texture images must be generated in advance simulation starts and simulations can only be performed in 2D spaces. In this paper, we propose a crowd agent behavior simulation method based on agent's 3D affordance field for flexible agent behavior in variable geomorphological environments in 3D space. The proposed method generates 3D affordance field related to agents and sensors in 3D space and defines the agent behavior in 3D space for the crowd behavior simulation based on an image-inducing field to a 3D space. Experimental results verified that our method enables the development of large-scale crowd behavior simulations that are flexible to various fire evacuation situations in 3D virtual spaces.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.645-648
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• 2008

초고층 복합공간이 증가하면서 건축물의 공간에서는 매우 복잡하고 다양한 상황들이 연출되는데, 이에 대한 관리는 아직도 관리자가 획득한 제한된 정보에 근거해서 내린 의사결정에 의존하고 있다. 그러나 인간의 능력은 한정된 시간 동안에, 제한된 정보를 분석하여, 상황에 맞는 적절한 조치를 취하는 데에는 한계가 있다. 이러한 한계점을 극복하기 위해 첨단 정보기술을 융합한 유비쿼터스 시스템을 이용할 수 있는 방안을 제안하고자 한다. 본 논문은 객체 지향 3D 데이터에 관한 연구 현황을 조사하여 3D 데이터 추출 방안, 시스템간의 데이터 교환 방안, 현재 객체 지향 3D 데이터의 활용 상황 등에 대한 정보를 수집하고, 다중이용시설물의 일반적인 공간 정보를 3D CAD 정보에서 추출하여 GIS 시스템으로 보낼 방안을 수립하고자 한다.

• 대한공간정보학회지
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• 제15권3호
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• pp.11-18
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• 2007

유비쿼터스와 관련된 다양한 기술로써 최근 3차원 GIS와 어플리케이션들은 점차 주목받고 있다. 대규모 복합 건물들이 생겨나면서 접근성과 같은 계량적인 측정이 요구되지만, 대부분 접근성과 관련된 연구들은 2차원 네트워크 기반으로 이루어 졌을 뿐 3차원 공간상에서의 접근성 분석에 관한 연구는 사례가 극히 드물다. 따라서 본 연구에서는 3차원 공간에서의 접근성을 산출하는 방법을 제안하고 기존의 전통적인 Space Syntax에서의 접근성 산출방법과 이를3차원 공간 내에 적용하기 위한 새로운 방법을 제시하고, 공간간의 거리, 방향전환, 층간 이동 등의 부하를 고려함으로써 공간의 깊이를 산출하였다. 개발된 방법은 캠퍼스 건물모델에 적용하여 비교 분석하였다.