• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.647-650
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• 2005

A new driving scheme, Address and Display Period Complex Driving for Expanding Gray Scale(ACE), is proposed by mixing Address Display period Separated(ADS) and Address While Display(AWD). In this method scan lines are divided in blocks driving by AWD and scan lines in block progress sequential high speed addressing. ADS driving get accomplished in low gray level for expanding gray scale. Scan time is reduced and the number of subfields is increased by high speed addressing of ACE. That expands the gray scale and decreases the dynamic false contour. Also, that improves contrast by using ramp reset.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1546-1549
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• 2009

In recent studies on tone reproduction with the objective of reproducing natural looking colors in digital images, an integrated multi-scale retinex (IMSR) has produced great naturalness in the resulting images. Most methods, including IMSR, work in RGB or quasi-RGB color spaces. As such, this produces hue distortion from the perspective of the human visual system. Accordingly, this paper proposes the hue preserved multi-scale Retinex (HPMSR) method to obtain a high contrast and naturalness. The proposed method enhanced the $L^*$ and saturation values in CIELAB color space. As a result, the visibility in dark shadows in the resulting images was improved.

• Korean Journal of Hospice Care
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• v.1 no.1
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• pp.1-17
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• 2001

The purpose of this study was to elucidate the effects of spiritual nursing intervention on pain and anxiety of the hospice patients. This study was devised with a quasi-experimental design using non-equivalent contrast group non-synchronized design. The data were collected during the period from July 10 to September 25 in 2000 at the general hospital in CheonJu city. The subjects were sixty-seven patients who referred the hospice service. They were assigned to two groups, 36 members of the experimental group and 30 members of the contrast group. They also did not any complication, were alert enough tobe interviewed and agree willingly to participate in this study. The tools used were Yoon's Korean Version of Brief Pain Inventory and Spielberger's State Anxiety Scale. The spiritual care intervention was carried out through Hymn, Scripture, Prayer, the therapeutic use of self over a period of three weeks. Data were analyzed by mean, standard deviation, $x^2$-test, t-test, paired t-test and Pearson's Correlation Coefficients. The results of this study were as follows: 1.The examination of the same quality showed that there were not significant differences in the general characters, disease and therapeutic characters, religional characters between the experimental group and the contrast group. 2.After the spiritual nursing intervention pain scores of the experimental group were remarkably lower than those of the contrast group(right now pain: t=-2.634, p=0.012). 3.Decreasing rate in the pain scores of the experimental group were remarkably lower than those of the contrast group(right now pain: t=5.017, p=0.000). 4. After the spiritual nursing intervention state anxiety of the experimental group were remarkably lower than those of the contrast group(t=-5.987, p=0.000). 5. A positive correlation was found between reported pain and depression following the spiritual nursing intervention. In conclusion, the hospice patients who were offered spiritual care became lower than those who were not offered spiritual care and confirmed to decrease pain. According to these results, spiritual nursing intervention can be regarded as an effective nursing intervention that relieved pain and anxiety of the hospice patients.

• Progress in Medical Physics
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• v.28 no.3
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• pp.83-91
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• 2017

In this work, we investigated the recently proposed phase-contrast x-ray imaging (PCXI) technique, the so-called single grid-based PCXI, which has great simplicity and minimal requirements on the setup alignment. It allows for imaging of smaller features and variations in the examined sample than conventional attenuation-based x-ray imaging with lower x-ray dose. We performed a systematic simulation using a simulation platform developed by us to investigate the image characteristics. We also performed a preliminary PCXI experiment using an established a table-top setup to demonstrate the performance of the simulation platform. The system consists of an x-ray tube ($50kV_p$, 5 mAs), a focused-linear grid (200-lines/inch), and a flat-panel detector ($48-{\mu}m$ pixel size). According to our results, the simulated contrast of phase images was much enhanced, compared to that of the absorption images. The scattering length scale estimated for a given simulation condition was about 117 nm. It was very similar, at least qualitatively, to the experimental contrast, which demonstrates the performance of the simulation platform. We also found that the level of the phase gradient of oriented structures strongly depended on the orientation of the structure relative to that of linear grids.

• Journal of Korean Neurosurgical Society
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• v.58 no.4
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• pp.321-327
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• 2015

Objective : To determine whether the use of contrast enhancement (especially its extent) predicts malignant brain edema after intra-arterial thrombectomy (IAT) in patients with acute ischemic stroke. Methods : We reviewed the records of patients with acute ischemic stroke who underwent IAT for occlusion of the internal carotid artery or the middle cerebral artery between January 2012 and March 2015. To estimate the extent of contrast enhancement (CE), we used the contrast enhancement area ratio (CEAR)-i.e., the ratio of the CE to the area of the hemisphere, as noted on immediate non-enhanced brain computed tomography (NECT) post-IAT. Patients were categorized into two groups based on the CEAR values being either greater than or less than 0.2. Results : A total of 39 patients were included. Contrast enhancement was found in 26 patients (66.7%). In this subgroup, the CEAR was greater than 0.2 in 7 patients (18%) and less than 0.2 in the other 19 patients (48.7%). On univariate analysis, both CEAR ${\geq}0.2$ and the presence of subarachnoid hemorrhage were significantly associated with progression to malignant brain edema (p<0.001 and p=0.004), but on multivariate analysis, only CEAR ${\geq}0.2$ showed a statistically significant association (p=0.019). In the group with CEAR ${\geq}0.2$, the time to malignant brain edema was shorter (p=0.039) than in the group with CEAR <0.2. Clinical functional outcomes, based on the modified Rankin scale, were also significantly worse in patients with CEAR ${\geq}0.2$ (p=0.003) Conclusion : The extent of contrast enhancement as noted on NECT scans obtained immediately after IAT could be predictive of malignant brain edema and a poor clinical outcome.

• The Journal of Internal Korean Medicine
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• v.40 no.5
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• pp.983-989
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• 2019

Objective: Many types of delayed adverse reactions, such as long-term numbness, occur after injecting contrast medium, but few clinical studies have reported effective treatments for these reactions. We report that herbal medicine can have a positive clinical effect in patients who have experienced long-term numbness after contrast medium injection. Method: A patient who had felt numbness in her head and whole limbs presented at Semyung University Korean Medicine hospital. Her numbness had first started 2 days after injection of contrast medium, and she had felt it constantly for almost 2 years. After admission at the hospital, she took "modified Samul-tang" herbal medicine (120 cc three times per day) from 29 January 2019 to 2 February 2019. We measured her numbness using a numeric rating scale (NRS) on 29 January and 2 February and we compared both scores to determine the degree of favorable and clinical effects of herbal medicine. Result: The NRS score for numbness was 5 for her head and limbs on the first day (29 January), but after 4 days (2 February), the NRS score decreased to 0 for her head and both arms and hands, and it decreased from 5 to 2 for both her legs and feet. Conclusion: Korean herbal medicine can have positive clinical effects on treating adverse reactions due to injection of contrast medium.

• Journal of Digital Convergence
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• v.13 no.9
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• pp.431-437
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• 2015

This convergence study analyzed the effectiveness of contrast agent reduction by normal saline solution dilution in the computed tomography of arteries of lower limb. 48 patients of 125 cc contrast agent and 30 patients of the same amount divided at a ratio of 7:3 for the contrast agent and normal saline solution were studied. The average attenuation coefficient(HU) and signal to noise ratio(SNR) of abdominal aorta, femoral artery, popliteal artery and posterior tibial artery at each image were evaluated quantitatively and the four criteria in the five point scale was conducted qualitatively by two radiologists and four radiological technologists. In the quantitative evaluation, both HU and SNR had high average score before dilation but there were no statistical significance by independent t-test(p>0.05). In the qualitative evaluation, there were a little differences in the average scores between 4.86~4.77 of original contrast agent and 4.83~4.67 of dilated contrast agent but there were no statistical significance(p>0.05). In the computed tomography of arteries of lower limb, the dilated contrast agent doesn't influence image quality and reduces overall contrast agent and lowers iodine content per unit of molecular therefore will contribute to decrease side effect of contrast agent.

• Journal of Multimedia Information System
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• v.5 no.2
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• pp.87-90
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• 2018

Various approaches have been proposed to convert low dynamic range (LDR) to high dynamic range (HDR). Of these approaches, the Multi Scale Fusion (MSF) algorithm based on Laplacian pyramid decomposition is used in many applications and demonstrates its usefulness. However, the pyramid fusion technique has no means for controlling the luminance component because the total number of pixels decreases as the pyramid rises to the upper layer. In this paper, we extract the reflection light of the image based on the Retinex theory and generate the weight map by adjusting the reflection component. This weighting map is applied to achieve an MSF-like effect during image fusion and provides an opportunity to control the brightness components. Experimental results show that the proposed method maintains the total number of pixels and exhibits similar effects to the conventional method.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.25-28
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• 2020

Automatic segmentation of brain tissues such as WM, GM, and CSF from brain MRI scans is helpful for the diagnosis of many neurological disorders. Accurate segmentation of these brain structures is a very challenging task due to low tissue contrast, bias filed, and partial volume effects. With the aim to improve brain MRI segmentation accuracy, we propose an end-to-end convolutional based U-SegNet architecture designed with multi-scale kernels, which includes cascaded dilated convolutions for the task of brain MRI segmentation. The multi-scale convolution kernels are designed to extract abundant semantic features and capture context information at different scales. Further, the cascaded dilated convolution scheme helps to alleviate the vanishing gradient problem in the proposed model. Experimental outcomes indicate that the proposed architecture is superior to the traditional deep-learning methods such as Segnet, U-net, and U-Segnet and achieves high performance with an average DSC of 93% and 86% of JI value for brain MRI segmentation.

• Journal of Acupuncture Research
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• v.33 no.2
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• pp.77-87
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• 2016

Objectives : This is a pilot study for a large randomized controlled trial to investigate the efficacy and safety of a newly developed contrast therapy device-- alternating topical heat and cold -- for patients with chronic low back pain. The main objective of this study is to confirm the feasibility of the study design. Methods : The design was a randomized, 2-arm, parallel-group, single-blind, placebo controlled trial. Patients in each group received real or sham contrast therapy in an acupuncture point 10 times over four weeks. The primary outcome measure was pain intensity on a 100-mm visual analogue scale (VAS). The secondary outcomes were back-related dysfunction based on the Oswestry Disability Index (ODI), the Roland-Morris disability questionnaire (RMDQ), and range of motion of lumbar spine based on the modified Schober test (mSchober test), Finger-to-Floor distance (FTF distance), and Finger-to-Thigh distraction (FTT distraction). Results : A total of 30 subjects with chronic low back pain were randomly assigned to a contrast therapy group (n＝15) or a sham group (n＝15). A repeated-measures analysis of variance showed statistically significant group time interaction for VAS, RMDQ, mSchober test and FTF distance (p<0.05). The treatment group showed significant improvement in pain intensity and functional disability as compared to the sham group. Conclusion : Contrast therapy may be an effective and safe treatment for chronic low back pain.