• 대한원격탐사학회지
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• 제40권2호
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• pp.167-177
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• 2024

With advancements in satellite technology, interest in target detection and identification is increasing quantitatively and qualitatively. Synthetic Aperture Radar(SAR) images, which can be acquired regardless of weather conditions, have been applied to various areas combined with machine learning based detection algorithms. However, conventional studies primarily focused on the detection of stationary targets. In this study, we proposed a method to identify moving targets using an algorithm that integrates sub-aperture SAR images and cosine similarity calculations. Utilizing a transformer-based deep learning target detection model, we extracted the bounding box of each target, designated the area as a region of interest (ROI), estimated the similarity between sub-aperture SAR images, and determined movement based on a predefined similarity threshold. Through the proposed algorithm, the quantitative evaluation of target identification capability enhanced its accuracy compared to when training with the targets with two different classes. It signified the effectiveness of our approach in maintaining accuracy while reliably discerning whether a target is in motion.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.428-435
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• 2017

In this paper, we propose a novel motion field estimation algorithm for which a U-disparity map and forward-and-backward error removal are applied in a vehicular environment. Generally, a motion exists in an image obtained by a camera attached to a vehicle by vehicle movement; however, the obtained motion vector is inaccurate because of the surrounding environmental factors such as the illumination changes and vehicles shaking. It is, therefore, difficult to extract an accurate motion vector, especially on the road surface, due to the similarity of the adjacent-pixel values; therefore, the proposed algorithm first removes the road surface region in the obtained image by using a U-disparity map, and uses then the optical flow that represents the motion vector of the object in the remaining part of the image. The algorithm also uses a forward-backward error-removal technique to improve the motion-vector accuracy and a vehicle's movement is predicted through the application of the RANSAC (RANdom SAmple Consensus) to the previously obtained motion vectors, resulting in the generation of a motion field. Through experiment results, we show that the performance of the proposed algorithm is superior to that of an existing algorithm.

• 한국멀티미디어학회논문지
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• 제21권1호
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• pp.18-25
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• 2018

In High Efficiency Video Coding (HEVC), integer motion estimation (IME) requires a large amount of computational complexity because HEVC adopts the high flexible and hierarchical coding structures. In order to reduce the computational complexity of IME, this paper proposes the search range reduction algorithm, which takes advantage of motion vectors similarity between different layers. It needs only a few modification for HEVC reference software. Based on the experimental results, the proposed algorithm reduces the processing time of IME by 28.1% on average, whereas its the $Bj{\emptyset}ntegaard$ delta bitrate (BD-BR) increase is 0.15% which is negligible.

• 융합신호처리학회논문지
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• 제10권2호
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• pp.132-135
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• 2009

비디오 데이터들의 효율적 색인과 검색을 위해서는 비디오 시퀀스의 유사도 측정방법이 매우 중요한 요소이다. 본 논문은 비디오 시퀀스에 대한 효율적인 유사도 측정을 위해 휘도 성분 투사법을 제안한다. 기존의 알고리즘들이 히스토그램, 윤곽선, 움직임등과 같은 특성을 사용한 반면 본 논문에서 제안한 알고리즘은 휘도 성분을 투사하는 방법을 사용하여 비디오 유사도 특성을 효율적으로 나타낼 수 있다. 비디오 데이터의 효율적인 색인과 계산량 감소를 위해 누적된 유사도에 의해 추출된 키프레임들을 이용하여 비디오 시퀀스의 유사도를 구하고 수정된 하우스도르프 거리를 사용하여 키프레임 묶음들의 유사도를 측정하였다. 실험결과 제안한 휘도투시법을 사용한 비디오 색인 기법이 유사도 특성에서 기존의 특성을 사용한 방법에 비해 확연한 정확도 및 성능 차이를 보였다.

• 대한산업공학회지
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• 제37권1호
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• pp.10-18
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• 2011

Ergonomic product design considering users' natural use motion is of importance to improve the usability and satisfaction of a product. A five-step process of product design was developed in the present study by measuring and analyzing users' natural product-use motion with a motion capture system. The developed process was applied to ergonomic design improvement of a half guard installation part of refrigerator; new guard designs (diagonal and arc shape) were developed with the process and evaluated in terms of validity during the development as two measures (task satisfaction and similarity of natural motion). According to the evaluation result, the satisfaction at putting in- and out-task of new guard designs ($6.3{\pm}0.5$ points) was significantly higher than that of existing guard designs ($3.3{\pm}1.0$ points); the difference between natural motion and product-use motion in new guard designs ($1.0{\pm}0.3cm$) was significantly less than that of existing guard designs ($2.0{\pm}0.2cm$). The proposed process of natural motion analysis and product design is applicable to ergonomic product design and evaluation.

• Journal of applied mathematics & informatics
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• 제33권1_2호
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• pp.203-210
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• 2015

We consider fractional Brownian motion and FARIMA process with Gaussian innovations and show that the suitably scaled distributions of the FARIMA processes converge to fractional Brownian motion in the sense of finite dimensional distributions. We figure out ACF function and estimate the self-similarity parameter H of FARIMA(0, d, 0) by using R/S method. Finally, we display power spectrum density of FARIMA process.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1997년도 Proceedings International Workshop on New Video Media Technology
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• pp.137-142
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• 1997

One of the inherent problems in constructing the sign language dictionary is how to make retrieval and comparison operations on the visual database of signs. This paper describes a retrieval method, especifically for Japanese signs. This method has a useful capability for flexible retrieval of the sign from a bilingual dictionary. Our method can retrieve similar signs to the given input. The retrieval mechanism is essentially based on similarity between the given verbal description and verbal descriptions in a retrieval database. The similarity measure of verbal descriptions can be considered as the approximations for the similarity of sign motion images. As a results of our experiment, the success ratio of the retrievals is 96% in averages.

• 한국통신학회논문지
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• 제25권5B호
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• pp.913-924
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• 2000

객체의 이동 궤적에 대한 효율적 기술기(descriptor) 및 이를 이용한 내용기반 비디오 검색 기술을 제안하였다. 정지 배경의 비디오에서 이동 객체를 추출한 후, 객체의 중심 좌표의 시간에 따른 이동 궤적을 2차 다항식의 매개변수로써 표현하였다. 또한, 카메라의 움직임이 있는 유동 배경의 비디오에서 비디오의 전역 움직임을 어파인(affine) 모델링한 후, 어파인 매개변수로써 카메라의 움직임을 식별하고 색인화 하였다. 이동 궤적에 대한 질의 매개변수와 색인화 된 매개변수간 유사도 정합에 의하여 내용 기반의 비디오 검색을 실현하였다. 제안한 기술은 일반 비디오에 대한 신속한 검색뿐만 아니라 감시 비디오 시스템의 효율적 운영에 기여할 수 있을 것으로 기대된다.

• 한국콘텐츠학회논문지
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• 제16권6호
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• pp.293-304
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• 2016

이 연구는 국내외 모션 인포그래픽 공모전 수상작을 대상으로 디자인 트렌드를 분석한 것이다. 정보디자인 측면에서 모션 인포그래픽 디자인 과정을 정보 구조화, 정보 시각화로 나누고 각 단계에서 고려되어야할 디자인 요소들을 추출하여 각 기준에 맞추어 작품들을 분석하였다. 분석결과 국내외 작품에서 함께 나타난 공통점들은 모션 인포그래픽이란 매체를 통한 커뮤니케이션이 어떤 방식으로 이루어지며 그 방식들의 효용성에 대해 이해할 수 있는 시사점을 주었다. 동시에 차이점을 통해서는 국내외의 모션 인포그래픽에 대한 인식의 차이점을 확인할 수 있었으며 국내 모션 인포그래픽의 다양성 부재, 표현의 획일화 등을 읽어낼 수 있었다. 본 연구의 분석결과는 모션 인포그래픽을 제작하는 실무와 교육 분야에서 디자인 전략 수립의 틀로 그 유용성을 제공할 것으로 본다.

• The Journal of Korean Physical Therapy
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• 제31권6호
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• pp.333-338
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• 2019

Purpose: Although previous studies on the screw-home movement (SHM) for autopsy specimen and walking of living persons conducted, the possibility of acquiring SHM based on inertial measurement units received little attention. This study aimed to investigate the possibility of measuring SHM for the non-weighted bearing using a micro-electro-mechanical system-based wearable motion capture system (MEMSS). Methods: MEMSS and camera-based motion analysis systems were used to obtain kinematic data of the knee joint. The knee joint moved from the flexion position to a fully extended position and then back to the start point. The coefficient of multiple correlation and the difference in the range of motion were used to assess the waveform similarity in the movement measured by two measurement systems. Results: The waveform similarity in the sagittal plane was excellent and the in the transverse plane was good. Significant differences were found in the sagittal plane between the two systems (p<0.05). However, there was no significant difference in the transverse plane between the two systems (p>0.05). Conclusion: The SHM during the passive motion without muscle contraction in the non-weighted bearing appeared in the entire range. We thought that the MEMSS could be easily applied to the acquisition of biomechanical data on the knee related to physical therapy.