• 한국전문물리치료학회지
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• 제29권2호
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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.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.654-659
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• 2001

In the virtual environment, reality can be enhanced by offering the motion based on a motion simulator in harmony with visual and auditory modalities. In this research, the Stewart platform based motion simulator has been developed. This motion simulator is driven by the electric motors, and offers the slightly wider workspace compared to the commercial available simulators. In order to compensate for the limited range of the motion platform, the washout filters with fixed coefficients have been usually adopted. In this paper the new approach is proposed to tune the filter coefficients based on the fuzzy logic on the real-time basis. It is shown that performance with the variable filter coefficients is better than that with the fixed ones. The driving simulator based on the bicycle dynamics was developed by integrating the motion simulator and graphic system.

• 한국통신학회논문지
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• 제22권8호
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• pp.1691-1697
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• 1997

This paper presents a new motion compensated error coding method suitable for region based image coding system. Compared with block based conding, the region based coding improves subjective quality as it estimates and compensates 2D (or 3D) translantional, rotational, and scaling motion for each regions. although the region based coding has this advantage, its merit is reduced as bock-DCT (2D-DCT) is used to encode motion-compensated error. To overcome this problem, a new region adaptive motion compensated error coding technique which improver subjective and objective quality in the region boundary is proposed in this paper. In the proposed method, regions with large error are estimated using contour of the regions and contrast between the regions. The regions estiated as those with large error are coded by arbitrarily shaped image segment coding method. The mask information of the coded regions is not transmitted because it is estimated as the same algorithm in the encoder and the decoder. The proposed region adaptive motion conpensated error coding method improves about 0.5dB when it is compared with conventional block based method.

• 한국통신학회논문지
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• 제27권3A호
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• pp.240-248
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• 2002

본 논문에서는 연속영상에서 움직이는 객체의 motion에 기반하여 영상을 분할하는 새로운 알고리즘을 제안하였다. 전체적인 분할 과정은 2단계로 구성되어진다. 첫 단계는 '픽셀 레이블링' 단계이며, 두 번째 단계는 'motion 분할' 단계이다. '픽셀 레이블링' 단계에서는 optical flow에 의해 발생하는 속도 벡터들의 크기에 따라 영상의 각 픽셀에 레이블을 부여한다. 'Motion 분할' 단계에서는 첫 단계에서 생겨난 불필요한 잡음을 제거하기 위해 motion 필드를 마코프 랜덤 필드로 모델링하여 에너지 최소화를 통해 motion을 분할한다. 실험결과, 제안된 알고리즘이 연속영상에서 움직이는 객체의 motion을 효율적으로 분할함을 확인할 수 있었다.

• 전자공학회논문지B
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• 제33B권3호
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• pp.96-108
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• 1996

In this paper, we propose an object-oriented coding method in low bit-rate channels using block-based motion vectors and residual image compensation. First, we use a 2-stage algorithm for estimating motion parameters. In the first stage, coarse motion parameters are estimated by fitting block-based motion vectors and in the second stage, the estimated motion parametes are refined by the gradient method using an image reconstructed by motion vectors detected in the first stage. Local error of a 6-parameter model is compensted by blockwise motion parameter correction using residual image. Finally, model failure (MF) region is reconstructed by a fractal mapping method. Computer simulation resutls show that the proposed method gives better performance than the conventional ones in terms of th epeak signal to noise ratio (PSNR) and compression ratio (CR).

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제15권1호
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• pp.27-34
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• 2015

For a vision-based driver assistance system, unusual motion detection is one of the important means of preventing accidents. In this paper, we propose a real-time unusual-motion-detection model, which contains two stages: salient region detection and unusual motion detection. In the salient-region-detection stage, we present an improved temporal attention model. In the unusual-motion-detection stage, three kinds of factors, the speed, the motion direction, and the distance, are extracted for detecting unusual motion. A series of experimental results demonstrates the proposed method and shows the feasibility of the proposed model.

• Journal of Information Processing Systems
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• 제7권1호
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• pp.103-110
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• 2011

In this paper, an adaptive motion vector smoothing scheme based on weighted vector median filtering is proposed in order to eliminate the motion outliers more effectively for improving the quality of side information in frame-based distributed video coding. We use a simple motion vector outlier reliability measure for each block in a motion compensated interpolated frame and apply weighted vector median filtering only to the blocks with unreliable motion vectors. Simulation results show that the proposed adaptive motion vector smoothing algorithm improves the quality of the side information significantly while maintaining low complexity at the encoder in frame-based distributed video coding.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2009년도 학술대회
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• pp.40-44
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• 2009

이 논문에서, 모바일 장치에서의 이미지 브라우징을 위한 모션 기반 상호 작용 방식의 가능성을 평가하였다. 이를 위해 모션을 기반으로 한 인터페이스와 상호작용 방법을 디자인 하였다. 디자인된 인터페이스를 평가하기 위해 이를 현재 모바일 장치에서 사용 가능한, 가속도계와 비전을 이용한 하드웨어와 고성능의 트랙커를 이용한 하드웨어로 구현하여 버튼 인터페이스와 비교 실험을 하였다. 그 결과 모션 인터페이스들의 경우 버튼 인터페이스에 비해, 사용자의 흥미를 유발할 수 있었고, 충분한 훈련을 거치면 사용성 및 사용자 성능의 증대 효과도 컸지만 버튼 인터페이스의 성능에는 미치지 못하였다.

• 한국과학교육학회지
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• 제33권3호
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• pp.664-678
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• 2013

This study aims to investigate gifted students' explanations for daily celestial motion from the Earth-based and heliocentric frames of reference. Eleven sixth-grade elementary school students were chosen for this study and data was collected through a questionnaire and an in-depth interview. The collected data was analyzed into celestial objects which are the Sun, the moon and the stars and analyzed based on the Earth-based and heliocentric perspectives again. As a result of the research, most gifted students were able to connect the Earth-based and heliocentric frames of reference with the Sun's daily apparent motion. However, they understood the daily apparent motion of the moon and the stars far less frequently compared to the Sun's motion and could not explain the Earth's rotation clearly. The result of the interview showed that the lack of understanding about the daily celestial motion was caused by inaccurate understanding of the Earth's rotation such as using memorized knowledge learned in school and guessing the answer.

• 한국멀티미디어학회논문지
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• 제17권8호
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• pp.915-922
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• 2014

We propose an adaptive zoom motion estimation method where a picture is divided into two areas based on the distance information with a depth camera : the one is object area and the other is background area. In the proposed method, the zoom motion is only applied to the object area except the background area. Further, the block size of motion estimation for the object area is set to smaller than that of background area. This adaptive zoom motion estimation method can be reduced at the complexity of motion estimation and can be improved at the motion estimation performance by reducing the block size of the object area in comparison with the conventional zoom motion estimation method. Based on the simulation results, the proposed method is compared with the conventional methods in terms of motion estimation accuracy and computational complexity.