• Physical Therapy Korea
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• v.29 no.2
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• pp.87-93
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• 2022

To solve the pathological problems of the musculoskeletal system based on evidence, a sophisticated analysis of human motion is required. Traditional optical motion capture systems with high validity and reliability have been utilized in clinical practice for a long time. However, expensive equipment and professional technicians are required to construct optical motion capture systems, hence they are used at a limited capacity in clinical settings despite their advantages. The development of information technology has overcome the existing limit and paved the way for constructing a motion capture system that can be operated at a low cost. Recently, with the development of computer vision-based technology and optical markerless tracking technology, webcam-based 3D human motion analysis has become possible, in which the intuitive interface increases the user-friendliness to non-specialists. In addition, unlike conventional optical motion capture, with this approach, it is possible to analyze motions of multiple people at simultaneously. In a non-optical motion capture system, an inertial measurement unit is typically used, which is not significantly different from a conventional optical motion capture system in terms of its validity and reliability. With the development of markerless technology and advent of non-optical motion capture systems, it is a great advantage that human motion analysis is no longer limited to laboratories.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.764-767
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• 2009

Motion capture systems allow to measure the precise position of markers on the human body in real time. These captured motion data, the marker position data, have to be fitted by a human skeleton model to represent the motion of the human. Typical human skeleton models approximate the joints using a ball joint model. However, because this model cannot represent the human skeleton precisely, errors between the motion data and the movements of the simplified human skeleton model happen. We propose in this paper a method for measuring a translation component of wrist, and elbow joints on upper limb using optical motion capture system. Then we study the errors between the ball joint model and acquired motion data. In addition, we discuss the problem to estimate motion of human joint using optical motion capture system.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.11
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• pp.1074-1080
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• 2006

Motion capture systems are gaining popularity in entertainment, medicine, sports, education, and industry, with animation and gaming applications for entertainment taking the lead. A wide variety of systems are available for motion capture, but most of them are complicated and expensive. In the general class of optical motion capture, two or more optical sensors are needed to measure the 3D positions of the markers attached to the body. Recently, a 3D motion capture system using two Position Sensitive Detector (PSD) optical sensors was introduced to capture high-speed motion of an active infrared LED marker. The PSD-based system, however, is limited by a geometric calibration procedure for two PSD sensor modules that is too difficult for common customers. In this research, we have introduced a new system that used a single PSD sensor unit to obtain 3D positions of active IR LED-based markers. This new system is easy to calibrate and inexpensive.

• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.25-32
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• 2007

In this paper, the abstract layer for motion capture system is designed and implemented to meet the various hardware and different capturing method. The abstract layer can offer the unified programming by providing device independent API(Application Programming Interface). The device drivers of the optical system and mechanical system are emulated to verify the designed abstract layer. The optical system employs the AOA Ole while the mechanical system uses BVH file. An application program is written to call the abstract layer functions to drive both optical and mechanical drivers and receive the frame data, simulated motion data, that are displayed sequentially on the computer screen by utilizing Direct3D.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.04a
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• pp.474-477
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• 2000

최근 3D 애니메이션 , 영화 특수효과 그리고 게임제작시 모션 캡처 시스템(Motion Capture System)을 통하여 실제 인간의 동작 및 표정을 수치적으로 측정해내어 이를 실제 애니메이션에 직접 사용함으로써 막대한 작업시간 및 인력 드리고 자본을 획기적으로 줄이고 있다. 그러나 기존의 모션 캡처 시스템은 고속 카메라를 이용함으로써 가격이 고가이고 움직임 추적에서도 여러 가지 문제점을 가지고 있다. 본 논문에서는 일반 저가의 카메라와 신경회로망 및 영상처리를 이용하여 얼굴 애니메이션용 모션 캡처 시스템에 적용할 수 있는 경제적이고 효율적인 얼굴 움직임 추적 기법을 제안한다.

• The Journal of the Korea Contents Association
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• v.7 no.8
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• pp.109-116
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• 2007

Motion Capture in multimedia contents of the imagination world is utilized in various field such as game, movie, TV. Motion Capture technology of most of game is utilized. As well as is more realistic if use motion Capture and superior time and monetary aspect than previous key frame (Key-Framing) way as well as can display screen that do dynamic, there is more excellent advantage in qualitative aspect. But, is utilizing in some specialty companies and use example was not informed much about problem when is very lacking, and utilize yet in learned circles. Extract motion data of various action using optic motion Capture of motion Capture equipment in this treatise, and investigated about problem that appear when applied in character that is different from a person.

• Journal of the Korea Computer Graphics Society
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• v.18 no.1
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• pp.23-28
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• 2012

In this paper, we present a new method for automatically synchronize captured facial expression data with its corresponding motion data. In a usual optical motion capture set-up, a detailed facial expression can not be captured simultaneously in the motion capture session because its resolution requirement is higher than that of the motion capture. Therefore, those are captured in two separate sessions and need to be synchronized in the post-process to be used for generating a convincing character animation. Based on the patterns of the actor's neck movement extracted from those two data, we present a non-linear time warping method for the automatic synchronization. We justify our method with the actual examples to show the viability of the method.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.4
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• pp.377-386
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• 2015

Joint force/torque estimation by inverse dynamics is a traditional tool in biomechanical studies. Conventionally for this, kinematic data of human body is obtained by motion capture cameras, of which the bulkiness and occlusion problem make it hard to capture a broad range of movement. As an alternative, inertial motion sensing using cheap and small inertial sensors has been studied recently. In this research, the performance of inertial motion sensing especially to calculate inverse dynamics is studied. Kinematic data from inertial motion sensors is used to calculate ground reaction force (GRF), which is compared to the force plate readings (ground truth) and additionally to the estimation result from optical method. The GRF estimation result showed high correlation and low normalized RMSE(R=0.93, normalized RMSE<0.02 of body weight), which performed even better than conventional optical method. This result guarantees enough accuracy of inertial motion sensing to be used in inverse dynamics analysis.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.831-835
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• 2006

Motion capture means the recording of movement of objects such as human beings, animals, creatures, machines, etc in a form applicable to computer. Since the motion capture system can be introduced to the fields where realistic movement of human beings and animals, which cannot be attained with an existing key frame method is required, large scale is necessary or economical burden exists, it has a merit and possibility of new expression. For these reasons, this method is increasingly used in the field of digital entertainment such as movie, TV, advertisement, documentary, music video, etc centering around the game. However, in spite of such an advantage, problems such as too much advance preparation work in digital image expressions using motion capture, marker attachment, compensation of motion data, motion retargeting and lack of professional human resources, etc. are becoming a prominent figure. Accordingly, this study intends to suggest the way of more effective production of motion capture digital image through finding the problems and their draft possible solutions in the production process based on the image production examples using motion capture.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.257-263
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• 2006

Nowadays, 3-D(Three-dimensions) is used in various field such as Games, Movies, Animations etc. Especially the Role of 3-D computer graphic is being generalized by turnover of Screen from '2-dimensional' to '3-dimensional'. There are not enough data about 'Motion Capture' even though it plays main function in 3-dimensional movement. 'Motion Capture' could be also unfamiliar for people. And as a matter of fact, the use of this equipment is limited due to its high cost. Therefore, I studied the outline of Digital Motion Capture system and its application to 3-D game Character Animation. And I checked the movement of 3-D Character after transplanting the Motion Data to the 3-D Character. I acquired Motion Data by Optical Motion Capture Equipment which we possess and transplanted it into the 3-D Character then Implemented it as walking, running and hitting which are the basic motions of Expression.