• Journal of Korea Multimedia Society
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• v.15 no.1
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• pp.9-17
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• 2012

Recently, a new image appearance model, named iCAM06, was developed for High-Dynamic-Range (HDR) image rendering. The dynamic range of a HDR image needs to be mapped on the range of output devices, which is called the tone reproduction or tone mapping. The iCAM06, the representative HDR rendering algorithm also uses the tone compression using a S-curve mapping function for image reproduction on the dynamic range of output devices. However the iCAM06 occurs white point shift during its tone compression process. Therefore, we propose a compensation method for white point shift problem using the corrected channel gain function. Experiment results show that the proposed method has better performance than the iCAM06.

• Journal of Korea Multimedia Society
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• v.16 no.3
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• pp.281-289
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• 2013

The iCAM06 has been used as an image appearance model for HDR image rendering. The iCAM06 goes through the color space conversions and scale conversions of the several steps to present HDR images. The dynamic range of an HDR image needs to be mapped on the range of output devices, which is called the tone mapping. However, tone compression process of the iCAM06 causes color distortion because of color-clipping and cross-stimulus. Therefore, we proposed that a color correction method in IPT space which compensates the color distortion in tone compression process. Through the experimental results, we conformed that proposed color correction method had better performance than the iCAM06 and enhanced models.

• The Journal of Korean Physical Therapy
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• v.35 no.1
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• pp.24-30
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• 2023

Purpose: The purpose of this study was to investigate the effectiveness of the elastic compression stockings and Kinesio taping on muscle activity and mechanical properties in healthy women during the heel raise exercise that causes muscle fatigue. Methods: Participants were divided into the elastic compression stockings group (ESG, n=8), Kinesio taping group (KTG, n=8), and control group (CG, n=8). All participants performed the heel raise exercise to cause muscle fatigue. Muscle activity, stiffness, and the muscle tone of the gastrocnemius and tibialis anterior were measured before and after the heel raise exercise. Results: In the gastrocnemius, muscle activity was significantly increased after the heel raise exercise in both the ESG and KTG (p<0.05). There was a significant difference in the change in the gastrocnemius muscle activity between the groups (p<0.05). Post hoc analysis showed that the ESG exhibited a significantly greater change in gastrocnemius muscle activity than the CG (p<0.05). The muscle stiffness of the gastrocnemius was significantly decreased after the heel raise exercise in the ESG (p<0.05). The muscle tone of the gastrocnemius was significantly increased after the heel raise exercise in the control group (p<0.05). There were no significant differences in the change in the gastrocnemius stiffness and muscle tone between the groups (p>0.05). In the tibialis anterior, there were no significant differences in muscle activity, stiffness, and muscle tone between and within the groups (p>0.05). Conclusion: Our findings suggest that the use of elastic compression stockings and Kinesio taping during the heel raise exercise are beneficial and delay muscle fatigue in the gastrocnemius.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.781-783
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• 1999

A storage or transmission of image is difficult without image compression processing because the numbers of generated or reborned image data are very much. In case of the random signal, image compression efficiency is low doing without loss of image information, but compressibility by using JPEG is better. We used Huffman code of JPEG, it assigne the low bit value for data of a lot of generated frequency, assigne the high bit value for data of a small quantity. This paper improved image compression efficiency with transformming Q-factor and certified the results with compressed image. A proposed method is very efficience for continuos a color tone image.

• Journal of the Korea Society of Computer and Information
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• v.26 no.11
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• pp.165-172
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• 2021

The purpose of this study was to identify differences in the muscle tone and stiffness of neck muscles according to levels of cardiopulmonary resuscitation (CPR) skill. The subjects were 30 female students in their 20s who were divided into a skilled group (n=15) and an unskilled group (n=15). According to the results, the skilled group showed statistically significant decreases in the stiffness of the lower cervical muscle and the muscle tone of the upper trapezius on the above hand side of hand grips after CPR (p<.05). The unskilled group exhibited a statistically significant difference in both the muscle tone and stiffness of the upper trapezius muscle on both sides after CPR (p<.05). However, no statistically significant differences were found between the two groups. In addition, the non-skilled group showed statistically significant lower values than the skilled group in the mean compression rate, total number of compressions, accuracy of chest compression, and accuracy of chest relaxation (p<.05). This study confirmed that CPR has a myophysiological effect on the neck muscles of those who perform CPR. However, it found that no differences result from individual CPR skill levels that are an important element for the accuracy of CPR.

• Proceedings of the IEEK Conference
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• 2000.06c
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• pp.93-96
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• 2000

Currently, the most important technology is the compression methods in the multimedia society. Audio files are rapidly propagated through internet. MP-3 is offered to CD tone quality in 128Kbps, but 64Kbps below tone quality is abruptly down and high bitrate. on the other hand, MPEG-II AAC (Advanced Audio Coding) is not compatible with MPEG-I, but AAC has a high compression ratio 1.4 better than MP-3. Especially, AAC has max. 7.1 channel and 96KHz sampling rate. In this paper, the perceptual model is dealt with 44.1KHz sampling rate for SMR(Signal to Masking Ratio)

• Proceedings of the IEEK Conference
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• 2000.11c
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• pp.97-100
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• 2000

The most important technology is the compression methods in the multimedia society. Audio files are rapidly propagated through internet. MP-3(MPEG-1 Layer3) is offered to CD tone quality in 128kbps, but 64kbps below tone-quality is abruptly down. On the other hand, MPEG-II AAC (Advanced Audio Coding) is not compatible with MPEG-I, but AAC has a high compression ratio 1.4 times better than MP-3 and it has max. 7.1 channel and 96KHz sampling rate. In this paper, we designed the optimized MDCT (Modified Discrete Cosine Transform) that could decrease the capacity of enormous computation and could increase the processing speed in the MPEG-2 AAC encoder.

• Journal of Korea Multimedia Society
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• v.12 no.8
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• pp.1055-1065
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• 2009

High-dynamic-range (HDR) rendering technology changes the range from the broad dynamic range (up to 9 log units) of a luminance, in a real-world scene, to the 8-bit dynamic range which is the common output of a display's dynamic range. One of the techniques, iCAM06 has a superior capacity for making HDR images. iCAM06 is capable of making color appearance predictions of HDR images based on CIECAM02 and incorporating spatial process models in the human visual system (HVS) for contrast enhancement. However there are several problems in the iCAM06, including obscure user controllable factors to be decided. These factors have a serious effect on the output image but users get into difficulty in that they can't find an adequate solution on how to adjust. So a suggested model gives a quantitative formulation for user controllable factors of iCAM06 to find suitable values which corresponds with different viewing conditions, and improves subjective visuality of displayed images for varying illuminations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3672-3684
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• 2015

Recently, the standardization of backward compatible JPEG image coding for high dynamic range (HDR) image has been undertaken to establish an international standard called "JPEG XT." The JPEG XT consists of two layers: the base layer and the residual layer. The base layer contains tone mapped low dynamic range (LDR) image data and the residual layer contains the error signal used to reconstruct the HDR image. This paper gives the result of a study to evaluate the overall performance of tone mapping operators (TMOs) for this standard. The evaluation is performed using five HDR image datasets and six TMOs for profiles A, B, and C of the proposed JPEG XT standard. The Tone Mapped image Quality Index (TMQI) and no reference image quality assessment (NR IQA) are used for measuring the LDR image quality. The peak signal to noise ratio (PSNR) is used to evaluate the overall compression performance of JPEG XT profiles A, B, and C. In TMQI and NR IQA measurements, TMOs using display adaptive tone mapping and adaptive logarithmic mapping each gave good results. A TMO using adaptive logarithmic mapping gave good PSNRs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.4
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• pp.1846-1863
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• 2016

High dynamic range (HDR) images can present the perfect real scene and rich color information. A commonly encountered problem in practical applications is how to well visualize HDR images on standard display devices. In this paper, we propose a multi-scale decomposition method using guided filtering for HDR image tone mapping. In our algorithm, HDR images are directly decomposed into three layers：base layer, coarse scale detail layer and fine detail layer. We propose an effective function to compress the base layer and the coarse scale detail layer. An adaptive function is also proposed for detail adjustment. Experimental results show that the proposed algorithm effectively accomplishes dynamic range compression and maintains good global contrast as well as local contrast. It also presents more image details and keeps high color saturation.