• The Journal of Korean Physical Therapy
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• 제22권6호
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• pp.43-51
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• 2010

Purpose: This study examined the influence of visuomotor congruency on learning a relative phase relationship between a single joint movement and an external signal. Methods: Participants (N=5) were required to rhythmically coordinate elbow flexion-extension movements with a continuous sinusoidal wave (0.375 Hz) at a $90^{\circ}$ relative phase relationship. The congruent group was provided online feedback in which the elbow angle decreased (corresponding to elbow flexion) as the angle trajectory was movingup, and vice versa. The incongruent group was provided online feedback in which the elbow angle decreased as the angle trajectory was moving down, and vice versa. There were two practice sessions (day 1 and 2) and each session consisted of 6 trials per block (5 blocks per session). Retention tests were performed 24 hours after session 2, and only the external sinusoidal wave was provided. Repeated ANOVAs were used for statistical analysis. Results: During practice, the congruent group was significantly less variable than the incongruent group. Phase variability in the incongruent group did not significantly change across blocks, while variability decreased significantly in the congruent group. In retention, the congruent group produced the required $90^{\circ}$ relative phase pattern with significantly less phase variability than the incongruent group. Conclusions: Congruent visual feedback facilitates learning. Moreover, the deprivation of online feedback does not affect the congruent group but does affect the incongruent group in retention.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.436-450
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• 2017

Recently, the method based on fractional order partial differential equation has been used in image processing. Usually, the optional order of fractional differentiation is determined by a lot of experiments. In this paper, a denoising model is proposed based on adaptive fractional order anisotropic diffusion. In the proposed model, the complexity of the local image texture is reflected by the local variance, and the order of the fractional differentiation is determined adaptively. In the process of the adaptive fractional order model, the discrete Fourier transform is applied to compute the fractional order difference as well as the dynamic evolution process. Experimental results show that the peak signal-to-noise ratio (PSNR) and structural similarity index measurement (SSIM) of the proposed image denoising algorithm is better than that of other some algorithms. The proposed algorithm not only can keep the detailed image information and edge information, but also obtain a good visual effect.

• 한국소음진동공학회논문집
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• 제16권4호
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• pp.414-419
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• 2006

In this research, the test how the evaluation of the spacial image influenced by the environmental friendly elements included in the visual information, and how the selection of the sound changed depending on the characteristics of spacial image were carried out by the 40 subjects. Vast tracts of green land and the waterfront were highly preferred and impressive than the other spaces. The green music, signal with water sound and bird chirping sound were highly scored. In the frequency characteristics of the factors, the first factor was artificial sound (high at the low frequency band), the second was natural sound(uniform at all frequency band) and the third was water sound (high at the middle and high frequency band over 500 Hz) . This shows that the proposal of the sound which has the frequency characteristics fit to the spacial image should be selected for the soundscape of the target space.

• 자원환경지질
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• 제21권2호
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• pp.185-191
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• 1988

A two channel seismic recorder suitable for long-term observation of microearthquakes is developed. The direct analogue recording on cassette tape is adopted in the recorder whose circuits of amplifier and mortor units of an audio cassette recorder are modified. The recorder provides contineous record of 10 days with DC 12V battery (100AH) and with standard cassette tape of 60 minute use. The binary coded time signals of date, hour, and minute are generated once a minute by the timing system and absolute time input using radio to measure the time drift is also possible. For the seismic signal processing, the analogue signals from audio cassette player pass A/D converter and digitized data are stored in personal computer. Then visual records can be obtained using computer graphic mode. Basic programs "ADCONVO" and "DRAWO" to accomplish A/D conversions, the creation of data files and visualization of signals were written. Some sample signals reproduced from the recorded tape are presented.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.4170-4188
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• 2014

In this study, we present a denoising algorithm for high-frame-rate videos in an ultra-low illumination environment on the basis of Kalman filtering model and a new motion segmentation scheme. The Kalman filter removes temporal noise from signals by propagating error covariance statistics. Regarded as the process noise for imaging, motion is important in Kalman filtering. We propose a new motion estimation scheme that is suitable for serious noise. This scheme employs the small motion vector characteristic of high-frame-rate videos. Small changing patches are intentionally neglected because distinguishing details from large-scale noise is difficult and unimportant. Finally, a spatial bilateral filter is used to improve denoising capability in the motion area. Experiments are performed on videos with both synthetic and real noises. Results show that the proposed algorithm outperforms other state-of-the-art methods in both peak signal-to-noise ratio objective evaluation and visual quality.

• 한국산업정보학회논문지
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• 제21권3호
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• pp.21-28
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• 2016

압축 센싱은 샤논/나이퀴스트 표본화 정리를 만족하는 나이퀴스트 율보다 더 적은 수의 표본화 주파수로 신호를 획득하더라도 그 신호가 성긴 신호라는 조건 하에 샘플링을 가능하게 하는 신호 처리 기술이다. 특히, BCS-SPL 구조는 가장 널리 사용되고 있는 방법 중에 한 가지이고, 현재에는 다양한 BCS-SPL 방식들이 연구되고 있다. 그러나 복원할 때, 블록크기는 복원 영상의 품질에 큰 영향을 미치고, 본 논문에서는 기본 구조와 더불어 구조화된 형태에 대해 다양한 블록 크기에 따라 성능을 비교한다. 다양한 실험 결과를 통하여 기본적인 구조의 BCS-SPL 알고리즘이 블록 크기 4일 때 가장 우수한 성능을 보여줌을 확인한다.

• Fibers and Polymers
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• 제6권1호
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• pp.66-71
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• 2005

The surface evenness and texture are closely related with the irregularity of yam thickness. Besides, yam thickness variation has an important role to influence the yam performance and the textile process efficiency. Thus, the information not only on the yam thickness, but also on the short- term irregular characteristics that have not been known before is required for enhancing the qualities of textile products. This paper reports the results of a study about the yam thickness and its variation for various types of yam on the basis of a new measurement system applying a laser slit beam as a light source. The new method delivers effective information on the irregularity. The analysis of the measured signal confirms that the visual shade created by the yam doubling and twisting can be measured and the yam thickness characteristics can be represented by corre­lograms. Depending on yam types, correlograms have different shapes and can be approximated to an exponentially decaying function with or without fluctuating magnitude. In addition, the effective information on the yam irregularity can be influ­enced by the sampling length interval of the measuring device used for tests.

• 대한전자공학회논문지SP
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• 제48권1호
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• pp.132-140
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• 2011

Ultra-High Definition Television (U-HDTV) 는 차세대 TV로 불리는 실감 TV의 가장 유망한 요소 기술로 주목받고 있으며 이를 효과적으로 압축하기 위한 병렬 비디오 부호화 기술 개발의 필요성이 증대되고 있다. 기존의 병렬 부호화 기술은 영상을 공간적으로 분할하고 분할비디오 (sub-sequence)를 독립적으로 부호화 하는 방식을 사용하였다. 본 논문에서는 분할비디오간의 높은 상호상관 (cross-correlation)을 이용하여 부호화 효율을 향상하는 파이프라인 (pipeline) 구조의 병렬 부 복호화기를 제안한다. 실험결과를 통하여 제안하는 기술이 압축 효율을 향상시키며 균일한 화질의 분할비디오를 생성하는 것을 확인한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1897-1900
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• 2002

This paper proposes a novel computer-human interface, named invisible Messenger. It integrates face detection and tracking, and speaker array signal processing. By speaker array it is possible to form acoustic focus at the arbitrary location that is measured by the face tracking. Thus the proposed system can whisper in a person's ear as if an invisible virtual messenger were standing by the person. Not only speculative discussion, the authors have implemented a working prototype system based upon the proposed idea. This paper also describes about this prototype. In order to confirm effectiveness of the proposed idea, the authors conduct experiments using the implemented system. Experimental results demonstrate the effectivenss of the proposed idea.

• Investigative Magnetic Resonance Imaging
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• 제22권2호
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• pp.86-93
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• 2018

Purpose: Imaging plays a significant role in diagnosing leptomeningeal metastases. However, the most appropriate sequence for the detection of leptomeningeal metastases has yet to be determined. This study compares the efficacies of contrast-enhanced T2 fluid attenuated inversion recovery (FLAIR) and contrast-enhanced 3D T1 black-blood fast spin echo (FSE) imaging for the detection of leptomeningeal metastases. Materials and Methods: Tube phantoms containing varying concentrations of gadobutrol solution were scanned using T2 FLAIR and 3D T1 black-blood FSE. Additionally, 30 patients with leptomeningeal metastases were retrospectively evaluated to compare conspicuous lesions and the extent of leptomeningeal metastases detected by T2 FLAIR and 3D T1 black-blood FSE. Results: The signal intensities of low-concentration gadobutrol solutions (< 0.5 mmol/L) on T2 FLAIR images were higher than in 3D T1 black-blood FSE. The T2 FLAIR sequences exhibited significantly greater visual conspicuity scores than the 3D T1 black-blood sequence in leptomeningeal metastases of the pial membrane of cistern (P = 0.014). T2 FLAIR images exhibited a greater or equal extent (96.7%) of leptomeningeal metastases than 3D T1 black-blood FSE images. Conclusion: Because of its high sensitivity even at low gadolinium concentrations, contrast-enhanced T2 FLAIR images delineated leptomeningeal metastases in a wider territory than 3D T1 black-blood FSE.