• Journal of the Korea Computer Graphics Society
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• v.29 no.1
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• pp.23-29
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• 2023

In this paper, we introduce a method to obtain high-quality results at a low cost for simulating musculoskeletal characters based on data from the reference motion through motion capture on two-legged walking through reinforcement learning. We reset the motion data of the reference motion to allow the character model to perform, and then train the corresponding motion to be learned through reinforcement learning. We combine motion imitation of the reference model with minimal metabolic energy for the muscles to learn to allow the musculoskeletal model to perform two-legged walking in the desired direction. In this way, the musculoskeletal model can learn at a lower cost than conventional manually designed controllers and perform high-quality bipedal walking.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.127-128
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• 2020

다양한 장치와 상황을 인식하여 사람에게 필요한 장치를 제어하는 기술 중 사람의 모션 인식을 활용한 응용과 서비스가 증가하고 있다. 이러한 기술들은 카메라를 이용하여 사람의 모션을 캡처하는 방식과 센서를 이용하여 상황을 유추하는 방식이 대표적이다. 그러나 사람의 모션을 인식하는 기존의 방식들은 큰 단위 움직임을 추적하기 때문에 드론제어와 같이 섬세하면서도 시간적으로 효과적인 작업이 필요한 응용 분야에 적용하기 어렵다. 본 논문에서는 사람의 손가락 동작을 기반으로 드론의 정밀하면서도 간편한 제어가 가능한 모션 인식 체계를 설계한다. 손가락 모션 인식 기반의 드론제어는 드론 축구 등과 같이 신속성과 정밀성이 필요한 분야의 서비스로 확장될 수 있다.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.439-444
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• 2008

The techniques, which locate example motions in abstract parameter space and interpolate them to generate new motion with given parameters, are widely used in real-time animation system for its controllability and efficiency However, as the dimension of parameter space increases for more complex control, the number of example motions for parameterization increases exponentially. This paper proposes a method that uses two different parameter spaces to obtain decoupled control over upper-body and lower-body motion. At each frame time, each parameterized motion space produces a source frame, which satisfies the constraints involving the corresponding body part. Then, the target frame is synthesized by splicing the upper body of one source frame onto the lower body of the other. To generate corresponding source frames to each other, we present a novel scheme for time-warping. This decoupled parameterization alleviates the problems caused by dimensional complexity of the parameter space and provides users with layered control over the character. However, when the examples are parameterized based on their upper body's spatial properties, the parameters of the examples are varied individually with every change of its lower body. To handle this, we provide an approximation technique to change the positions of the examples rapidly in the parameter space.

• Journal of KIISE:Software and Applications
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• v.35 no.11
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• pp.671-680
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• 2008

Motion capture devices have been utilized in producing several contents, such as movies and video games. However, since motion capture devices are expensive and inconvenient to use, motions segmented from captured data was recycled and synthesized to utilize it in another contents, but the motions were generally segmented by contents producers in manual. Therefore, automatic motion segmentation is recently getting a lot of attentions. Previous approaches are divided into on-line and off-line, where ow line approaches segment motions based on similarities between neighboring frames and off-line approaches segment motions by capturing the global characteristics in feature space. In this paper, we propose a graph-based high-level motion segmentation method. Since high-level motions consist of repeated frames within temporal distances, we consider similarities between neighboring frames as well as all similarities among all frames within the temporal distance. This is achieved by constructing a graph, where each vertex represents a frame and the edges between the frames are weighted by their similarity. Then, normalized cuts algorithm is used to partition the constructed graph into several sub-graphs by globally finding minimum cuts. In the experiments, the results using the proposed method showed better performance than PCA-based method in on-line and GMM-based method in off-line, as the proposed method globally segment motions from the graph constructed based similarities between neighboring frames as well as similarities among all frames within temporal distances.

• Journal of the Korea Computer Graphics Society
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• v.23 no.3
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• pp.1-8
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• 2017

In this paper, we introduce a technique to retarget human motion data to the humanoid body in a constrained environment. We assume that the given motion data includes detailed interactions such as holding the object by hand or avoiding obstacles. In addition, we assume that the humanoid joint structure is different from the human joint structure, and the shape of the surrounding environment is different from that at the time of the original motion. Under such a condition, it is also difficult to preserve the context of the interaction shown in the original motion data, if the retargeting technique that considers only the change of the body shape. Our approach is to separate the problem into two smaller problems and solve them independently. One is to retarget motion data to a new skeleton, and the other is to preserve the context of interactions. We first retarget the given human motion data to the target humanoid body ignoring the interaction with the environment. Then, we precisely deform the shape of the environmental model to match with the humanoid motion so that the original interaction is reproduced. Finally, we set spatial constraints between the humanoid body and the environmental model, and restore the environmental model to the original shape. To demonstrate the usefulness of our method, we conducted an experiment by using the Boston Dynamic's Atlas robot. We expected that out method can help the humanoid motion tracking problem in the future.

• Cartoon and Animation Studies
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• s.28
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• pp.125-153
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• 2012

This study is regarding what motion modality has influences on aspects of genre and media. Nowadays, motion modality becomes an element which is actively manipulated in live actions as well as animations. And, it has been generally accepted that a strategy on manipulation of motion depends on matters of genre or medium. As respected, can we say the premise is correct? if it is, can we refine the premise more theoretically, without using the words, 'genre' or 'media' which have not been are not been defined on an academic aspect. I intend to discuss on this issue. I will speculate the issue of manipulation of motion modality on theoretical bases. According to McLuhan's hot/cool media theory and Bolter's oscillation theory, the effect of it turns out to be same as manipulation of sentience ratio of media readers, and the ideal result will be examined by an example analysis. In the analysis, I will explore what effects manipulation of motion has on several examples. Then, by examining what kind of correlation these effects has with media/genre positioning, I ultimately will evaluate the genre/medium-based determinism of motion modality, which is represented by a typical premise like "Animation is most realistic when it has the most animation-like movement." Conclusively I suggest a refined premise like the following. Modality of motion is a strategy depending on issues of genre, with no regard to issues of medium, and the issue of genre is a category which is positioned considering mixture ratio of sentience. With this reason, A strategy of modality of motion depends to sentience a certain sequence needs. So, motion modality becomes a strategy which has to be approached in functionality of genre rather than economic values which spring from technical devices like a motion capture.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.11b
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• pp.123-128
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• 1999

본 논문에서는 기존에는 샷 경계 검출에 초점을 맞춘 것과는 달리 본 논문에서는 샷 보다 상위레벨인 비디오 씬 추출에 초점을 맞추어 디지털 비디오를 구조화하는 시스템을 제안한다. 샷간의 유사도를 측정하기 위해서 칼라와 모션 특징을 이용하였으며, 비디오 내의 동적 또는 정적 특성을 반영하기 위해서 적응적 가중치를 적용하였다. 칼라 특징을 추출하기 위해서 각 샷의 내부에서 대표 프레임을 추출하였고, 각 샷 내부의 모션 정보는 MPEG 비디오 모션 벡터를 이응해서 추출하였다. 또한, 비디오 씬 분할 시 연산 시간을 줄이기 위한 기법을 제시하였다. 마지막으로 추출된 비디오 씬에 대해서 성능평가를 하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.622-624
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• 2000

모션 캡쳐 데이터를 이용하는 애니메이션에서 가장 큰 이슈는 재사용이다. 같은 동작이지만 약간의 변화가 있는 동작을 하는 데이터를 얻기 위해 다시 모션 캡쳐 장비를 가지고 작업을 해야 한다면 많은 시간과 돈의 낭비를 초래하게 된다. 모션 캡쳐 데이터의 재사용에 대한 연구 중 동작 적응은 이미 존재하는 모션 캡쳐 데이터를 다른 가상 캐릭터에 적용하는 문제를 다루고 있다. 지금까지의 연구는 동작배우와 가상 캐릭터의 길이 차이에만 초점을 맞추어 진행되었다. 그러나 본 연구에서는 길이의 차이와 함께 부피의 차이를 모두 고려하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.175-175
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• 2004

애니메이션과 컴퓨터 게임 등의 다양한 산업에 이용되고 있는 모션캡쳐 시스템은 현재 카메라를 이용한 고가의 고속 카메라를 사용하여 일반인들이 범용으로 사용하기에는 많은 어려움이 따른다. 이에 본 연구에서는 고가의 고속카메라를 사용하는 대신 저가의 PSD 센서를 사용하여 광학방식의 모션캡쳐 시스템을 구성하였다. 또한 시스템에서 획득한 3 차원 데이터의 정확성을 위해 일반적으로 CCD 카메라에 사용되어지는 카메라 보정 알고리즘을 PSD 모션캡쳐 시스템에 적용하여 손쉽게 보정을 하면서 적은 오차를 가질 수 있는 방법을 제시하였다.(중략)

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.11a
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• pp.47-52
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• 2002

가상공간에서 탑승자에게 운동감을 제공하기 위해서 수많은 형태의 모션 시뮬레이터가 개발되어 왔다. 하지만 이러한 형태의 시뮬레이터들은 그 고유한 형태에 의해 정해진 동역학과 워시아웃 알고리즘을 거쳐야만 정밀한 시뮬레이터가 될 수 있다. 본 논문은 기존의 좁은 시야공간에서의 시뮬레이터가 아닌 넓은 시야를 제시하고, 모션 베이스와 독립적으로 운영되는 영상 제시기를 이용하여 탑승자에게 운동감을 제공하는 분리형 시뮬레이터를 대상으로 하여 영상과 모션을 동기화시켜서 제시하는 방법에 대해 논의하고자 한다.