• 한국통신학회논문지
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• 제34권10B호
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• pp.1086-1092
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• 2009

Stereoscopic conversion has been an important and challenging issue for many 3-D video applications. Usually, there are two different stereoscopic conversion approaches, i.e., image motion-based conversion that uses motion information and object-based conversion that partitions an image into moving or static foreground object(s) and background and then converts the foreground in a stereoscopic object. As well, since the input sequence is MPEG-1/2 compressed video, motion data stored in compressed bitstream are often unreliable and thus the image motion-based conversion might fail. To solve this problem, we present the utilization of key-motion that has the better accuracy of estimated or extracted motion information. To deal with diverse motion types, a transform space produced from motion vectors and color differences is introduced. A key-motion is determined from the transform space and its associated stereoscopic image is generated. Experimental results validate effectiveness and robustness of the proposed method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권10호
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• pp.2448-2463
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• 2013

The traditional block-based motion compensation methods in frame rate up-conversion (FRUC) only use a single uniquely motion vector field. However, there will always be some mistakes in the motion vector field whether the advanced motion estimation (ME) and motion vector analysis (MA) algorithms are performed or not. Once the motion vector field has many mistakes, the quality of the interpolated frame is severely affected. In order to solve the problem, this paper proposes a novel joint overlapped block motion compensation method (8J-OBMC) which adopts motion vectors of the interpolated block and its 8-neighbor blocks to jointly interpolate the target block. Since the smoothness of motion filed makes the motion vectors of 8-neighbor blocks around the interpolated block quite close to the true motion vector of the interpolated block, the proposed compensation algorithm has the better fault-tolerant capability than traditional ones. Besides, the annoying blocking artifacts can also be effectively suppressed by using overlapped blocks. Experimental results show that the proposed method is not only robust to motion vectors estimated wrongly, but also can to reduce blocking artifacts in comparison with existing popular compensation methods.

• Nuclear Engineering and Technology
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• 제52권4호
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• pp.721-733
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• 2020

In nuclear engineering, the occurrence of critical heat flux (CHF) is complicated for rod bundle, and it is much more difficult to predict the CHF when it is in natural circulation under motion condition. In this paper, the dryout-type CHF is investigated for the rod bundle in a natural circulation loop under rolling motion condition based on the coupled analysis of subchannel method, a one-dimensional system analysis method and a CHF mechanism model, namely the three-fluid model for annular flow. In order to consider the rolling effect of the natural circulation loop, the subchannel model is connected to the one-dimensional system code at the inlet and outlet of the rod bundle. The subchannel analysis provides the local thermal hydraulic parameters as input for the CHF mechanism model to calculate the occurrence of CHF. The rolling motion is modeled by additional motion forces in the momentum equation. First, the calculation methods of the natural circulation and CHF are validated by a published natural circulation experiment data and a CHF empirical correlation, respectively. Then, the CHF of the rod bundle in a natural circulation loop under both the stationary and rolling motion condition is predicted and analyzed. According to the calculation results, CHF under stationary condition is smaller than that under rolling motion condition. Besides, the CHF decreases with the increase of the rolling period and angular acceleration amplitude within the range of inlet subcooling and mass flux adopted in the current research. This paper can provide useful information for the prediction of CHF in natural circulation under motion condition, which is important for the nuclear reactor design improvement and safety analysis.

• 한국게임학회 논문지
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• 제16권4호
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• pp.97-104
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• 2016

이 연구는 단편 애니메이션 'Drip'을 통해 키 프레임 애니메이션과 모션 캡처 애니메이션을 융합하여 애니메이션 제작을 실현하는 기법을 제안한다. 상호 유기적 연결을 통해 효율적인 프로세스 관리가 가능할 뿐만 아니라 키 프레임 애니메이션과 모션 캡처 애니메이션의 단점을 서로 보완하는 과정을 처리함으로써 제작 기간을 단축 시켰다. 이를 통해 키 프레임 애니메이션과 모션 캡처 애니메이션의 한계를 극복하고 복합적인 프로세스를 인지하고 응용하여 효율적인 애니메이션 제작에 도움이 되고자 한다.

• 방송공학회논문지
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• 제7권3호
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• pp.219-228
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• 2002

본 논문에서는 2D 동영상을 스테레오스코픽(Stereoscopic) 동영상으로 변환하는 새로운 방법을 제안한다. 일반적으로 영상의 운동정보를 이용하여 스테레오스코픽 영상을 생성한다. 그러나 얻어진 운동 정보는 신뢰도가 낮을 수가 있고, 이것은 스테레오스코픽 영상 생성 단계에서 오류 발생의 원인이 된다. 상기 문제점의 해결 방안으로 운동 벡터 정보의 신뢰도가 높고 추정된 운동 유형이 정확한 키 프레임(Key Frame)을 활용하는 스테레오스코픽 변환 방법을 제안한다. 또한 각 운동 유형에 따른 스테레오스코픽 변환 방법을 소개한다. 제안한 스테레오스코픽 변환 방법의 성능 검증을 위해 다양한 실험 영상에 적용하고 키 프레임의 운동유형의 정확도를 측정하였다. 실험에서는 평균 90％이상의 키 프레임과 그 운동 유형을 정확히 찾는 성능을 얻었다.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1374-1381
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• 2022

Under the influence of nuclear radiation, the reliability of steam generators (SGs) is an important factor in the efficiency and safety of nuclear power plant (NPP) reactors. Motion planning that remotely manipulates an SG mobile tube-inspection robot to inspect SG heat transfer tubes is the mainstream trend of NPP robot development. To achieve motion planning, conditional traversal is usually used for base position optimization, and then the A^* algorithm is used for path planning. However, the proposed approach requires considerable processing time and has a single expansion during path planning and plan paths with many turns, which decreases the working speed of the robot. Therefore, to reduce the calculation time and improve the efficiency of motion planning, modifications such as the matrix method, improved parent node, turning cost, and improved expanded node were proposed in this study. We also present a comprehensive evaluation index to evaluate the performance of the improved algorithm. We validated the efficiency of the proposed method by planning on a tube sheet with square-type tube arrays and experimenting with Model SG.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권12호
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• pp.3315-3337
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• 2012

Crowded scenes analysis is a challenging topic in computer vision field. How to detect diverse motion patterns in crowded scenarios from videos is the critical yet hard part of this problem. In this paper, we propose a novel approach to mining motion patterns by utilizing motion information during both long-term period and short interval simultaneously. To capture long-term motions effectively, we introduce Motion History Image (MHI) representation to access to the global perspective about the crowd motion. The combination of MHI and optical flow, which is used to get instant motion information, gives rise to discriminative spatial-temporal motion features. Benefitting from the robustness and efficiency of the novel motion representation, the following motion pattern mining is implemented in a completely unsupervised way. The motion vectors are clustered hierarchically through automatic hierarchical clustering algorithm building on the basis of graphic model. This method overcomes the instability of optical flow in dealing with time continuity in crowded scenes. The results of clustering reveal the situations of motion pattern distribution in current crowded videos. To validate the performance of the proposed approach, we conduct experimental evaluations on some challenging videos including vehicles and pedestrians. The reliable detection results demonstrate the effectiveness of our approach.

• 한국콘텐츠학회논문지
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• 제7권8호
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• pp.109-116
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• 2007

가상세계의 멀티미디어 콘텐츠에 있어 모션캡처는 게임, 영화, TV등 다양한 분야에서 활용되고 있다. 게임의 대부분은 모션캡처 기술이 활용되고 있다. 모션 캡처를 이용하면 보다 사실적이고 다이나믹한 화면을 나타낼 수 있을 뿐만 아니라 이전의 키 프레임(Key-Framing)방식보다 시간과 금전적 측면에서 우수할 뿐만 아니라 질적인 면에서도 훨씬 뛰어난 이점이 있다. 그러나 몇몇 전문 업체에서 활용하고 있으며 학계에서는 아직 사용 예가 매우 부족하며, 활용 시 문제점에 대해서도 많이 알려지지 않았다. 본 논문에서는 모션 캡처 장비 중 광학식 모션캡처를 이용하여 다양한 동작의 모션 데이터를 발췌하고, 사람과 다른 캐릭터에 적용할 시 나타나는 문제점에 대해 고찰해 보았다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권4호
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• pp.938-958
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• 2024

Unsupervised Video Object Segmentation (UVOS) is a highly challenging problem in computer vision as the annotation of the target object in the testing video is unknown at all. The main difficulty is to effectively handle the complicated and changeable motion state of the target object and the confusion of similar background objects in video sequence. In this paper, we propose a novel deep Dual-stream Co-enhanced Network (DC-Net) for UVOS via bidirectional motion cues refinement and multi-level feature aggregation, which can fully take advantage of motion cues and effectively integrate different level features to produce high-quality segmentation mask. DC-Net is a dual-stream architecture where the two streams are co-enhanced by each other. One is a motion stream with a Motion-cues Refine Module (MRM), which learns from bidirectional optical flow images and produces fine-grained and complete distinctive motion saliency map, and the other is an appearance stream with a Multi-level Feature Aggregation Module (MFAM) and a Context Attention Module (CAM) which are designed to integrate the different level features effectively. Specifically, the motion saliency map obtained by the motion stream is fused with each stage of the decoder in the appearance stream to improve the segmentation, and in turn the segmentation loss in the appearance stream feeds back into the motion stream to enhance the motion refinement. Experimental results on three datasets (Davis2016, VideoSD, SegTrack-v2) demonstrate that DC-Net has achieved comparable results with some state-of-the-art methods.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2009년도 춘계학술대회
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• pp.109-112
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• 2009

The purpose of this study was to examine the differences in the brain activation evoked by music arranged in major and minor key used with an identical motion film during the fMRI testing. A part of the audio-visual combinations composed by Iwamiya and Sano were used for the study stimuli. This audio- visual clip was originally developed by combining a small motion segment of the animation "The Snowman" and music arranged in both major and minor key from the original jazz music "Avalon" rewritten in a classical style. Twenty-seven Japanese male graduate and undergraduate students participated in the study. Brain regions more activated by the major key than the minor key when presented with the identical motion film were the left cerebellum, the right fusiform gyrus, the right superior occipital, the left superior orbito frontal, the right pallidum, the left precuneus, and the bilateral thalamus. On the other hand, brain regions more activated by the minor key than the major key when presented with the identical motion film were the right medial frontal, the left inferior orbito frontal, the bilateral superior parietal, the left postcentral, and the right precuneus. The study showed a difference in brain regions activated between the two different stimulus (i.e., major key and minor key) controlling for the visual aspect of the experiment. These findings imply that our brain systematically generates differently in the way it processes music written in major and minor key(Supported by the User Science Institute of Kyushu University, Japan and the Korea Science and Engineering Foundation).