• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.5
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• pp.55-61
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• 2007

In this paper, we propose a three-dimensional(3D) active shape models for medical image segmentation. In order to build a 3D shape model, we need to generate a point distribution model(PDM) and select corresponding landmarks in all the training shapes. The manual determination method, two-dimensional(2D) method, and limited 3D method of landmark correspondences are time-consuming, tedious, and error-prone. In this paper, we generate a 3D statistical shape model using the 3D model generation method of a distance transform and a tetrahedron method for landmarking. After generating the 3D model, we extend the shape model training and gray-level model training of 2D active shape models(ASMs) and we use the integrated modeling process with scale and gray-level models for the appearance profile to represent the local structure. Experimental results are comparable to those of region-based, contour-based methods, and 2D ASMs.

• 한국IT서비스학회:학술대회논문집
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• 2009.05a
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• pp.559-568
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• 2009

현대 생활에서 u-Health는 특히 우리나라에서 Ubiquitous 와 Wellness의 개념을 접목하여 구현 하고 있으며, 현재 앞선 IT기술과 활성화된 Network 기반의 환경을 활용하여 발전된 결과를 도출 하려 하고 있다. 하지만 u-Health 장비 또는 프로그램에서 3D시뮬레이션 기법이 어떻게 쓰이면 그 활용도가 증가 되고, 올바른 활용 방법인가에 대해서 연구는 시작 단계라고 할 수 있다. 이에 현재 가정용 게임기와 일부 기능성 컨텐츠에서 쓰이는 3D 시뮬레이션 기법에서 체력증진을 위한 단계별 학습법과 신체 부분별 시뮬레이션에 효과적인 방법을 개발 정형화 시키고 시뮬레이션시 사용자와 가상의 시뮬레이터간의 상호작용 시 발생하는 문제점을 파악하고 해결 방안을 제시 하도록 하며, 3차원 3D기법 과 S/W 를 통하여 상호 작용을 할 때 체계적인 건강증진 방법과 건강관리방법을 제시 하고, 3차원 시뮬레이터를 활용 할 때 효과적인 항목과 결과 데이터를 통하여 발전적인 활용 방안을 제시 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.3C
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• pp.297-303
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• 2009

Integral imaging is a well-known 3D image recording and display technique. The huge size of integral imaging data requires a compression scheme to store and transmit 3D scenes. In the conventional compression scheme, the data amount of elemental images depends on the various recording condition such as the positional location of a 3D object, the illumination and specification of the lenslet array even if an identical pickup system is used. In this paper, to reduce the dependence of the image characteristics of elemental images on the pickup conditions, a compression scheme using block division on the elemental image of integral imaging is proposed. The proposed scheme provides an improved compression ratio by considering the local similarity of elemental images picked up from three-dimensional objects according to a positional location. To test the proposed scheme, various elemental images are picked up and a compression process is then carried out u sing a standard MPEG-4. Based on compression ratio results, the proposed compression scheme is improved by approximately 9% compared with the conventional compression method.

• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.127-140
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• 2020

Since the first episode of (1995) by Pixar, a world leading animation company, 3D animation has been focused on realistic motion and rendering techniques. However, in 2018, 3D animation was released, with unique backgrounds created through illustration techniques and dynamic movements of characters that seemed to be produced by hand rather than computers. It shows a lot of difference from other 3D animations. In this study, I analyzed 's new production techniques and expressions into two categories, first, the use of old comics techniques, and second, other factors that made the animation stand out. in 3D animation market focused on realistic motion and rendering techniques can have positive implications in terms of expanding animation diversity. This study is expected to be used as academic or research data for researchers studying new production techniques in related fields.

• Journal of Korea Multimedia Society
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• v.6 no.5
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• pp.896-908
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• 2003

Interaction technique in .3D virtual environment is a decisive factor that affects the immersion and presence felt by users in virtual space. Especially, in fields that require exquisite manipulation of objects such as electronic manuals in desktop environment, interaction technique that supports effective and natural manipulation of object is in demand. In this paper, 3D scene graph can be internally divided and reconstructed to a list defending on the users selection and through moving focus among the selection candidate objects list, the user can select 3D object more accurately Also, by providing various feedbacks for each manipulation stage, more effective manipulation is possible. The proposed technique can be used as 3D user interface in areas that require exquisite object manipulation.

• Journal of Korea Multimedia Society
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• v.10 no.3
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• pp.381-390
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• 2007

3D object contents are used for various applications in the Web virtual space, where the main concerns are to navigate the 3D virtual space and visualize 3D objects. The techniques to manipulate 3D objects like disassembling and assembling and to record the manipulation process are the very first step. Until now, we can record only the result of 3D object manipulation. Thus, we have tried to study the representation technique to record meaningfully and replay the manipulation process of 3D structured objects. We analyzed the structures and their relations between components to construct 3D objects that are described in XML or VRML. Compared to the previous method, we studied a XML based annotation technique to record and store selectively by user. This technique makes 3D structured objects be used in the various applications by the selective recording and also selective replaying.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.3A
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• pp.197-204
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• 2009

Cyclic delay diversity (CDD) is considered a simple approach to exploit the frequency diversity, to improve the system performance in orthogonal frequency division multiplexing (OFDM) systems. Also, the linear preceding technique can significantly improve the performance of communication systems by exploiting the channel state in formation (CSI). In order to achieve enhanced performance, we propose applying linear preceding to the conventional CDD-OFDM transmit diversity schemes over Rayleigh fading channels. The proposed scheme works effectively with the accurate CSI in time-division-duplex (TDD) OFDM systems with CDD, where the reciprocity is ass umed instead of channel state feedback. For a BER of $10^{-4}$ and the mobility of 3 km/h, simulation results show that a gain of 6 dB is achieved by the proposed scheme over both flat fading and Pedestrian A (Ped A) channels, compared to the conventional CDD-OFDM system. On the other hand, for a mobility of 120 km/h, a gain of 2.7 dB and 3.8 dB is achieved in flat fading and Vehicular A (Veh A) channels, respectively.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.44-53
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• 2011

In this paper, we propose a 3D conversion algorithm of 2D video using depth layer partition method. In the proposed algorithm, we first set frame groups using cut detection algorithm. Each divided frame groups will reduce the possibility of error propagation in the process of motion estimation. Depth image generation is the core technique in 2D/3D conversion algorithm. Therefore, we use two depth map generation algorithms. In the first, segmentation and motion information are used, and in the other, edge directional histogram is used. After applying depth layer partition algorithm which separates objects(foreground) and the background from the original image, the extracted two depth maps are properly merged. Through experiments, we verify that the proposed algorithm generates reliable depth map and good conversion results.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.219-222
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• 2006

본 연구는 디지털 문화의 출현이라는 맥락에서 디지털 시대의 환경 변화를 맞이한 애니메이션 제작 기법의 변화 속에서 셀 애니메이션 작품과 혼합하여 사용한 3D 컴퓨터 그래픽스(3D Computer Graphics) 기법 중 비사실적 이미지 기법(Non Photo Realistic Rendering)의 범주에 속한 카툰 렌더링(Cartoon Rendering) 기법을 분석하고 그것이 갖는 PC기반 실시간으로 수행되는 비사실적 렌더링을 위한 실시간 카툰렌더링 기법을 제시하고 있다. 종래의 카툰렌더링에 대해 연구하고 기존의 비사실적 이미지 기법의 적용에 대해 알아본다.

• Journal of Broadcast Engineering
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• v.26 no.3
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• pp.327-330
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• 2021

In this paper, a new noise filling method is proposed for improving the performance of the 3D audio codec. In the new method, the core band is limited up to MAX_SFB, not up to the IGF start frequency. And the noise filling is applied to all frequency range of the IGF source patches. We conduct the MUSHRA test and find that the proposed noise filling method demonstrates better performance than the conventional method.