• International Journal of Control, Automation, and Systems
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• v.5 no.6
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• pp.701-706
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• 2007

The measurement accuracy for heart rate or $SpO_2$ using photoplethysmography (PPG) is influenced by how well the noise from motion artifacts and other sources can be removed. Eliminating the motion artifacts is particularly difficult since its frequency band overlaps that of the basic PPG signal. Therefore, we propose the Periodic Moving Average Filter (PMAF) to remove motion artifacts. The PMAF is based on the quasi-periodicity of the PPG signals. After segmenting the PPG signal on periodic boundaries, we average the $m^{th}$ samples of each period. As a result, we remove the motion artifacts well without the deterioration of the characteristic point.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.860-863
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• 2003

Pulse oximetry has gained wide spread clinical acceptance in the latter part of the 21st century. The principle of pulse oximetry is based on the red and infrared light absorption features and uses a light emitter with red and infrared LEDs that shines through a reasonably translucent site with good blood flow. There are two methods of sending light through the measuring site : transmission and reflectance. After the transmitted red and infrared signals pass through the measuring site and received at the photodetector, the red/infrared ratio is calculated. But, pulse of oximeters are so sensitive that they may detect pulses when pressure is too low to provide adequate tissue blood flow, that is, SpO2 may decrease due to O2 consumption by the finger of the pulsing but stagnant arterial blood at low pressure or with vasoconstriction. This project has the limitations of pulse oximetry. Therefore, this paper is focused on the resuction of motion artifact that caused by moving when someone measures with SpO2 system.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.100-100
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• 2006

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.11C
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• pp.1097-1105
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• 2002

In display systems employing analog monitors, the tearing artifact such that an window screen is divided into two parts showing different scenes can occur when the change of scenes in the moving pictures is very fast, but the frame buffer's refresh rate does not match the monitor's scanning frequency. It is especially noticeable at high frame rate. DVR system is a recently popularized visual monitoring system. The tearing artifacts becomes more serious since the frame buffer's refresh rate is very high due to the requirement of multi channel display in the DVR. In this paper, we propose an improved display system for windows-based DVR systems which prevents the tearing artifacts without deterioration of display speed performance. The efficiency of the proposed display system is verified through experiments.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.2
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• pp.28-32
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• 2014

Purpose Patient motion during myocardial perfusion SPECT can produce images that show visual artifacts and perfusion defects. This artifacts and defects remain a significant source of unsatisfactory myocardial perfusion SPECT. Motion correction has been developed as a way to correct and detect the patient motion for reducing artifacts and defects, and each motion correction uses different algorithm. We corrected simulated motion patterns with several motion correction methods and compared those images. Materials and Methods Phantom study was performed. The anthropomorphic torso phantom was made with equal counts from patient's body and simulated defect was added in myocardium phantom for to observe the change in defect. Vertical motion was intentionally generated by moving phantom downward in a returning pattern and in a non-returning pattern throughout the acquisition. In addition, Lateral motion was generated by moving phantom upward in a returning pattern and in a non-returning pattern. The simulated motion patterns were detected and corrected similarly to no-motion pattern image and QPS score, after Motion Detection and Correction Method (MDC), stasis, Hopkins method were applied. Results In phantom study, Changes of perfusion defect were shown in the anterior wall by the simulated phantom motions, and inferior wall's defect was found in some situations. The changes derived from motion were corrected by motion correction methods, but Hopkins and Stasis method showed visual artifact, and this visual artifact did not affect to perfusion score. Conclusion It was confirmed that motion correction method is possible to reduce the motion artifact and artifactual perfusion defect, through the apply on the phantom tests. Motion Detection and Correction Method (MDC) performed better than other method with polar map image and perfusion score result.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.681-684
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• 2008

Motion interpolation is adopted and has been spread widely into market since it is effective in reducing motion blur, which is considered as weak characteristic due to slow response time of liquid crystal and hold-type display. 120Hz driving using interpolated frames achieves better moving picture quality with less motion blur and less motion judder. However, errors in the interpolated frames can cause visual artifacts such as static text breakup, halos, and occlusions. This paper focuses on categorizing characteristics of visual artifacts and on reducing side-effects by using information from original frames in special cases.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.315-318
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• 1997

The ECG-NIBP patient monitor consist of Noninvasive Blood Pressure(NIBP) module that have micro controller inside. This module transfer data by serial communication to the main processor. This system apply the fuzzy inflating method to reduce the blood pressure measuring time, and moving artifact removing algorithm, several parameters used or more accurate measurement. The ECG monitor use the Digital Signal Processor(DSP) or digital filtering, peak detection, heart rate calculation. This system also offer convenient user interface by rotary key, menu bar. With 7" CRT display, auxiliary TFT LCD display adapted to display information on wide screen.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.327-328
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• 2007

A contour shape matching based pixel motion estimation is proposed. The pixel motion information is very useful to compensate the motion artifact generated at the specific gray level contours in the moving image for subfield gray-scale display devices. In this motion estimation method, the gray level boundary contours are extracted from the input image. Then using contour shape matching, the most similar contour in next frame is found, and the contour is divided into segment unit. The pixel motion vector is estimated from the displacement of the each segment in the contour by segment matching. From this method, more precise motion vector can be estimated and this method is more robust to image motion with rotation or from illumination variations.

• Journal of IKEEE
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• v.17 no.4
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• pp.459-468
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• 2013

Under nonlinear characteristics of frames, we propose the frame interpolation using GRNN to enhance the visual picture quality. By full search with block size of 128x128~1x1 to reduce blocky artifact and image overlay, we select the frame having block of minimum error and re-estimate the nonlinear moving vector using GRNN. We compare our scheme with forward(backward) motion compensation, bidirectional motion compensation when the object movement is large or the object image includes zoom-in and zoom-out or camera focus has changed. Experimental results show that the proposed method provides better performance in subjective image quality compared to conventional MCFI methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.576-582
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• 2011

In this paper, we proposed the improved Advanced Detail Enhancement algorithm that improve the blurring by the lossy compression with CODEC and reduce the ringing artifacts in restoration. The conventional algorithm needs much amount of the process by the use of RGB color space. To improve this, we only used the luminance value in YCbCr color space. We verified that the performance of the improved algorithm with Y color value, the luminance value, is equal to the conventional algorithm with RGB color value and that the operation time of the improved is shorter about 24% than the conventional through the measurement of the operation time with Kodak standard images.