• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.08a
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• pp.179-182
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• 2008

본 연구에서는 3D 애니메이션 기법을 이용하여 기계 내부의 동작을 표현하였고, 도입된 기법의 장단점을 비교 검토하였다. 본 연구에서 표현한 애니메이션의 기획은 다양한 기계의 동작의 핵심원리에 목표를 두었다. 또한 본 연구에서는 실제에 가까운 애니메이션을 제작하기 위하여 기계 동작애니메이션을 Key 애니메이션 방법과, 링크를 사용한 IK 방법뿐만 아니라 Bone 애니메이션 방법에 대하여 장단점을 파악하고, 각각의 기계 내부 동작 표현에 대한 방법을 분류하였다. 본 연구가 콘텐츠화 된 시뮬레이션을 만드는데 하나의 프로세스로서 상당부분 기여할 수 있음을 확인하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1690-1695
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• 2008

The 3D virtual reality digital recovery technique is a new type in protecting and displaying remains and cultural relics through which the information of cultural relics can easily be known anytime and any where. The dissertation focuses on the study of the contradiction between quality and loading speed.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.1
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• pp.69-76
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• 2017

Purpose: The purpose of this study was to verify dosimetric results and reproducibility of position during craniospinal irradiation (CSI) using tomotherapy (Accuray Incorporated, USA). Also, by comparing with conventional CSI Technique, we confirmed the efficiency of using a Tomotherapy. Materials and Methods: 10 CSI patients who get tomotherapy participate. Patient-specific quality assurances (QA) for each patient are conducted before treatment. When treating, we took Megavoltage Computed Tomography (MVCT) that range of head and neck before treatment, L spine area after treatment. Also we conducted in-vivo dosimetry to check a scalp dose. Finally, we made a 3D conventional radiation therapy(3D-CRT) of those patients to compare dosimetric differences with tomotherapy treatment planning. Results: V107, V95 of brain is 0 %, 97.2 % in tomotherapy, and 0.3 %, 95.1 % in 3D-CRT. In spine, value of V107, V95 is 0.2 %, 18.6 % in tomotherapy and 89.6 %, 69.9 % in 3D-CRT. Except kidney and lung, tomotherapy reduced normal organ doses than 3D-CRT. The maximum positioning error value of X, Y, Z was 10.2 mm, -8.9 mm, -11.9 mm. Through in-vivo dosimetry, the average of scalp dose was 67.8 % of prescription dose. All patient-specific QA were passed by tolerance value. Conclusion: CSI using tomotherapy had a risk of parallel organ such as lung and kidney because of integral dose in low dose area. However, it demonstrated dosimetric superiority at a target and saved normal organ to reduce high dose. Also results of reproducibility were not exceeded margins that estimated treatment planning and invivo dosimetry showed to reduce scalp dose. Therefore, CSI using tomotherapy is considered to efficient method to make up for 3D-CRT.

• Broadcasting and Media Magazine
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• v.19 no.1
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• pp.10-21
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• 2014

3D 산업의 발달과 함께 음원을 통해 현장에서 느낄 수 있는 입체감을 재현하는 실감 음향 기술에 대한 관심 또한 증가하고 있다. 정확한 실감 음향을 구현하기 위해서 헤드폰과 스피커 시스템을 이용한 연구가 활발하게 진행되고 있다. 특히 스피커를 이용하는 실감 음향 연구는 초다채널 스피커를 이용하여 물리적 음장 재현을 목표로 하는 방법과 소채널 스피커를 이용하여 사용자의 특성을 적용한 인지적 음장 재현을 목표로 하는 방법으로 나뉜다. 헤드폰과 스피커를 이용한 기존 연구들이 사용하는 기술들에 대해서 알아보고, 기존 기술의 장점과 단점에 대해서 분석해본다. 이를 통해 사용자 맞춤형 실감 음향 기술의 구현을 위한 연구 방향과 새롭게 적용할 수 있는 기술들에 제시하고자 한다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.4
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• pp.223-237
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• 2011

The intermittent freshwater discharge has an critical influence upon the biophysical environments and the ecosystems of the Yeongsan Estuary where the estuary dam altered the continuous mixing of saltwater and freshwater. Though freshwater discharge is controlled by human, the extreme events are mainly driven by the heavy rainfall in the river basin, and provide various impacts, depending on its magnitude and frequency. This research aims to evaluate the magnitude and frequency of extreme freshwater discharges, and to establish the magnitude-frequency relationships between basin-wide rainfall and freshwater inflow. Daily discharge and daily basin-averaged rainfall from Jan 1, 1997 to Aug 31, 2010 were used to determine the relations between discharge and rainfall. Consecutive daily discharges were grouped into independent events using well-defined event-separation algorithm. Partial duration series were extracted to obtain the proper probability distribution function for extreme discharges and corresponding rainfall events. Extreme discharge events over the threshold 133,656,000 $m^3$ count up to 46 for 13.7y years, following the Weibull distribution with k=1.4. The 3-day accumulated rain-falls which occurred one day before peak discharges (1day-before-3day -sum rainfall), are determined as a control variable for discharge, because their magnitude is best correlated with that of the extreme discharge events. The minimum value of the corresponding 1day-before-3day-sum rainfall, 50.98mm is initially set to a threshold for the selection of discharge-inducing rainfall cases. The number of 1day-before-3day-sum rainfall groups after selection, however, exceeds that of the extreme discharge events. The canonical discriminant analysis indicates that water level over target level (-1.35 m EL.) can be useful to divide the 1day-before-3day-sum rainfall groups into discharge-induced and non-discharge ones. It also shows that the newly-set threshold, 104mm, can just separate these two cases without errors. The magnitude-frequency relationships between rainfall and discharge are established with the newly-selected lday-before-3day-sum rainfalls: $D=1.111{\times}10^8+1.677{\times}10^6{\overline{r_{3day}}$, (${\overline{r_{3day}}{\geqq}104$, $R^2=0.459$), $T_d=1.326T^{0.683}_{r3}$, $T_d=0.117{\exp}[0.0155{\overline{r_{3day}}]$, where D is the quantity of discharge, ${\overline{r_{3day}}$ the 1day-before-3day-sum rainfall, $T_{r3}$ and $T_d$, are respectively return periods of 1day-before-3day-sum rainfall and freshwater discharge. These relations provide the framework to evaluate the effect of freshwater discharge on estuarine flow structure, water quality, responses of ecosystems from the perspective of magnitude and frequency.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.211-213
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• 2011

본 연구에서는 도시화, 국토개발 등을 통해 빠르게 달라지고 있는 거주공간 및 자연환경의 원형을 사이버공간에 친환경적으로 표현하여 환경교육 학습자료로 활용하기 위한 컨텐츠로 조선시대 마을의 거주공간 및 자연환경의 원형을 3D기술(가상현실, 3D Max)을 이용하여 사이버공간에 재현하는 환경 교육용 가상체험 프로그램을 개발하고자 한다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.3
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• pp.129-137
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• 2005

In this study, we developed a model to simulate the interaction between sediment and the overlying water. The model deals with water-sediment interaction in terms of the sedimentation of organic detritus from the pelagic zone into the benthic zone and the release of nutrients occurring in the reverse direction. The model was tested and verified by comparing the predicted release rates of phosphorus from the sediment in Osaka Bay with actual observed values. The results accurately reproduced the seasonal change in release rates. The results well represented seasonal change of the release rates. A long-term prediction of water and sediment quality was performed for the period from 1950 to 1999. Nutrient loads from land and the boundary conditions of 3-D baroclinic flows were season-adjusted. The model accurately reproduced the changing trends in phosphorus, nitrogen, and COD concentrations in Osaka Bay over a long period of time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.1
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• pp.36-43
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• 2021

In this research, the accuracy of YOLO v3 algorithm in object detection during AGV (Automated Guided Vehicle) operation was investigated. First of all, AGV with 2D LiDAR and stereo camera was prepared. AGV was driven along the route scanned with SLAM (Simultaneous Localization and Mapping) using 2D LiDAR while front objects were detected through stereo camera. In order to evaluate the accuracy of YOLO v3 algorithm, recall, AP (Average Precision), and mAP (mean Average Precision) of the algorithm were measured with a degree of machine learning. Experimental results show that mAP, precision, and recall are improved by 10%, 6.8%, and 16.4%, respectively, when YOLO v3 is fitted with 4000 training dataset and 500 testing dataset which were collected through online search and is trained additionally with 1200 dataset collected from the stereo camera on AGV.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.07a
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• pp.353-354
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• 2012

최근 입체영상구현 기술연구는 현실감 있는 영상을 제작하기 위해서 다양하고 새로운 영상 제작방법들이 시도되고 있다. 하지만 입체영상 재현의 기술적 문제에 집중되어 있고 3D 그래픽스를 기반으로 한 입체영상 제작 기술에 관한 연구는 부족한 실정이다. 또한 그래픽스 환경에서 입체영상콘텐츠에 대한 입체감을 극대화 할 수 있는 기법이 필수적이다. 따라서 본 연구는 3차원 입체영상을 제작하는 과정에서 그래픽스 환경에서 실재감 있는 영상을 제작하기 위한 다양한 입체제작 원리와 제작을 활용한 영상보정 기법을 사용하여 키스톤 왜곡에 대한 현상을 보정하고 구현 가능한 제작방법을 제시하였다.

• Smart Media Journal
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• v.1 no.3
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• pp.36-42
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• 2012

Recently, the smart applications, such as smart phone and smart TV, become a hot issue in IT consumer markets. In particular, the smart TV provides 3D video services, hence efficient coding methods for 3D video data are required. Three-dimensional (3D) video involves stereoscopic or multi-view images to provide depth experience through 3D display systems. Binocular cues are perceived by rendering proper viewpoint images obtained at slightly different view angles. Since the number of viewpoints of the multi-view video is limited, 3D display devices should generate arbitrary viewpoint images using available adjacent view images. In this paper, after we explain a view synthesis method briefly, we propose a new algorithm to compensate view synthesis errors around object boundaries. We describe a 3D warping technique exploiting the depth map for viewpoint shifting and a hole filling method using multi-view images. Then, we propose an algorithm to remove boundary noises that are generated due to mismatches of object edges in the color and depth images. The proposed method reduces annoying boundary noises near object edges by replacing erroneous textures with alternative textures from the other reference image. Using the proposed method, we can generate perceptually inproved images for 3D video systems.