• Journal of Korea Multimedia Society
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• 제5권6호
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• pp.609-615
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• 2002

In this paper, we propose a contrast for the improvement of multi-gray scale image on display system. The proposed method distinguishes a maximum value and a minimum value in input fields or frames. By this judgement, the improvement degree of image quality is decided. This method does not require field and frame memory. Moreover, its lower hardware complexity than conventional methods make it easy to apply this method for flat panel display(FPD) which requires real-time processing. And the contrast of input gray level can be controled flexibly by varying the weight the weight value which controls the contrast range. The proposed method gives an image by controlling weighting slope selectively at intervals according to the brightness-control algorithm and the type of image in the look-up table. The function of the proposed method has been verified through Synopsys VHDL and computer simulation. And its results show that the proposed method can improve the quality of image.

• Transactions of the Korean Society of Mechanical Engineers B
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• 제23권3호
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• pp.398-407
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• 1999

In the present image processing technique, the concept of the gradient indicator(GI) has been introduced to find out the depth-of-field in sizing large particles ranging from $30{\mu}m$ to $30{\mu}m$ where using of the concept of the normalized contrast value(VC) is not appropriate. The gradient indicator is defined as the ratio of the local value to the maximum possible value of the gray-level gradient in an image frame. The gradient indicator decreases with the increases of the particle size and the distance from the exact focal plane. A particle is considered to be in focus when the value of the gradient indicator at its image boundary stays above a critical value. This critical gradient indicator($GI_{critical}$) is defined as the maximum gradient indicator($GI_{max}$) subtracted by a constant ${\Delta}GI$ which is to account for the particle-size effect. In the present ca.so, the value of ${\Delta}GI$ was set to 0.28 to keep the standard deviation of the measured particles mostly within 0.1. It was also confirmed that, to find the depth-of-field for small particles(${\leq}30{\mu}m$) with the same measurement accuracy, tho concept of the critical normalized contrast($VC_{critical}$) is applicable with 85% of the maximum normalized contrast value($VC_{max}$). Finally, the depth-of-field was checked for the size range between $10{\mu}m$ and $300{\mu}m$ when the both in-focus criteria ($GI_{critical}$ and $VC_{critical}$) were adopted. The change of the depth-of-field with the particle size shows good linearity in both the VC-applicable and the GI-applicable ranges with a reasonable accuracy.

• Journal of Korea Multimedia Society
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• 제18권10호
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• pp.1197-1204
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• 2015

Smoke detection plays an important role for the early detection of fire. In this paper, we suggest a newly developed method that generated LBPV(Local Binary Pattern Variance)s as special feature vectors from RGB contrast images can be applied to detect smoke using SVM(Support Vector Machine). The proposed method rearranges mean value of the block from each R, G, B channel and its intensity of the mean value. Additionally, it generates RGB contrast image which indicates each RGB channel’s contrast via smoke’s achromatic color. Uniform LBPV, Rotation-Invariance LBPV, Rotation-Invariance Uniform LBPV are applied to RGB Contrast images so that it could generate feature vector from the form of LBP. It helps to distinguish between smoke and non smoke area through SVM. Experimental results show that true positive detection rate is similar but false positive detection rate has been improved, although the proposed method reduced numbers of feature vector in half comparing with the existing method with LBP and LBPV.

• Journal of Korean Ophthalmic Optics Society
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• 제4권1호
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• pp.63-68
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• 1999

It was made of a chart by new method to be measured the contrast sensitivity for a spatial frequency, and the mean luminance of a lattice frequency was made to three forms of 25, 50, 75% and let it to be ready a CS value from 0 to $10^3$. As a result of measuring of the CS value for a spatial frequency on a target of 12 year old students, CS value decreased of according to down the average luminance value and also the peak position shift to low spatial frequency. The low visioned person decreased the CS value in side of high frequency or in space of total frequency. By the lattice adaptation, a measured CS value was decreased in circumstance regions of adapted space frequency.

• Investigative Magnetic Resonance Imaging
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• 제26권1호
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• pp.10-19
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• 2022

Purpose: To evaluate whether the added value of contrast leakage information from dynamic susceptibility contrast magnetic resonance imaging (DSC MRI) is a better prognostic imaging biomarker than the cerebral blood volume (CBV) value in distinguishing true progression from pseudoprogression in glioblastoma patients. Materials and Methods: Forty-nine glioblastoma patients who had undergone MRI after concurrent chemoradiotherapy with temozolomide were enrolled in this retrospective study. Twenty features were extracted from the normalized relative CBV (nCBV) and extraction fraction (EF) map of the contrast-enhancing region in each patient. After univariable analysis, we used multivariable stepwise logistic regression analysis to identify significant predictors for differentiating between pseudoprogression and true progression. Receiver operating characteristic (ROC) analysis was employed to determine the best cutoff values for the nCBV and EF features. Finally, leave-one-out cross-validation was used to validate the best predictor in differentiating between true progression and pseudoprogression. Results: Multivariable stepwise logistic regression analysis showed that MGMT (O⁶-methylguanine-DNA methyltransferase) and EF max were independent differentiating variables (P = 0.004 and P = 0.02, respectively). ROC analysis yielded the best cutoff value of 95.75 for the EF max value for differentiating the two groups (sensitivity, 61%; specificity, 84.6%; AUC, 0.681 ± 0.08; 95% CI, 0.524-0.837; P = 0.03). In the leave-one-out cross-validation of the EF max value, the cross-validated values for predicting true progression and pseudoprogression accuracies were 69.4% and 71.4%, respectively. Conclusion: We demonstrated that contrast leakage information parameter from DSC MRI showed significance in differentiating true progression from pseudoprogression in glioblastoma patients.

• Korean Journal of Digital Imaging in Medicine
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• 제9권1호
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• pp.17-19
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• 2007

This study applies in case of operating an exam using by the contrast order or inputting an order of a contrast media the exam of Radiology Department. It is developed for helping decision making as regards a process of an exam from reading the creatinine value automatically linked with Laboratory Information System. It can be confirmed by real-time information; therefore, the creditability of the information is able to be improved. We will create the base for Patient Monitoring System with the data from the side effect of the creatinine value and allergies. Decision Support System minimize the inconvenience and the riskiness of the given contrast medium for CT tests. We would like to improve medical services by providing a standard circumstance where patients are able to run tests safely and comfortably.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제14권3호
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• pp.1294-1300
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• 2013

The purpose of this study is to increase contrast to noise ratio(CNR) in myocardial viability test by using contrast agent which highly content gadolinium(1mmol/mL) maximizing diagnostic value. This research method that four hundred four patients were underwent the MRI scanning two hundred eighty four of them were injected commercial contrast media which have 0.5mmol/L and the rest of them were injected new contrast media(gadobutrol) which have 1mmol/mL of molarity to study the contrast difference depending on the molarity of the contrast agent signal intensities of normal ventricle and left ventricle were measured to compare and evaluate signal to noise ratio(SNR) and CNR of the images. As result, 1mmol/mL contrast agent showed higher SNR by 25.13% in myocardium and 30.74% in left ventricle. CNR was proved to be better in 1mmol/mL contrast agent by 31.29%. The results above were all statistically meaningful. Therefore, contrast agent contenting more gadolinium which was 1mmol/mL in this study, could more effectively shorten T1 relaxation time, increase the signal intensity and at the same time maximize CNR and diagnostic value. This study firstly report the usefulness of 1mmol/mL contrast agent in patients allegedly suffering cardiac diseases and it is considered to increase diagnostic value.

• Journal of the Korean Society of Costume
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• 제54권4호
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• pp.41-53
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• 2004

The significant role of colors in fashion design is not enough to emphasize in terms of one of the important design elements and its influences on the behaviors of the people. The purpose of this research is to examine the traditional Chinese colors and its ways of color combinations to appreciate the Chinese culture and its people. The Chinese traditional costume of Ching Dynasty were investigated through historic records, historic nobles, costume accessories and so on. The results of the study were summarized as follows： (1) The Blue was the most favoured color for clothing among men and women during Ching dynasty and various blues in terms of hue, value and intensities were used. (2) The bright Yellow which had been a symbol of Emperor were prohibited being used among people. Though, the late period of Dynasty, the regulation became not to strict and various shades of yellow families were adapted among People. (3) The Red which had been preferred during Ming Dynasty were constantly favoured for the formal wears of auspicious events such as weddings. (4) Dark color groups were loved for the clothing which were used as a ground colors against the flamboyant patterns revealing strong visual effects through value contrast or primary color combinations. (5) The White had a symbol of mourning and there were some intentions to adopt pale color groups such as mint, jade, gray, moon whit,. silver white to make up for white. (6) Contrast color combinations were one of the basic ways of color combination in Chinese traditional costume. Therefore Chinese color combinations has a strong visual effect and easy to draw attention of people by the contrast of the hue, value or intensity of color. (7) Multi-color combinations were another characteristics of Chinese costume in the formal wears which bears many surface designs. The surface decorated with full of motifs, were appreciated by the people expressing their longings and hopes through the auspicious meanings of patterns and striking visual effects of color combinations.

• The Transactions of the Korean Institute of Electrical Engineers D
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• 제53권2호
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• pp.76-85
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• 2004

In this paper, the contrast enhancement method of thermal image is proposed and it is the plateau equalization algorithm using local histogram for the real time display of infrared imagery. Through hardware implementing, its practicality and adequacy are proved. Examinations are executed to verify the effect of contrast enhancement by bright control and contrast control automatic to the plateau value in the manual mode, and that verified the effect of contrast enhancement in the automatic mode and the practicality in the real system. According to the experiment results, the proposed "the application of local histogram and plateau equalization algorithm for contrast enhancement of real time thermal image"in this dissertation is the verified method for the thermal imaging contrast enhancement.

• The Journal of Internal Korean Medicine
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• 제3권1호
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• pp.23-32
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• 1986

As a result of administration of Coptidis Rhizoma extract and Zingiberis Rhizoma extract to Rat and Rabbit, its effect to the Gastric Juice Volume, Acidity, Pepsin out put of Rat and the movement of Intestine, Pulse Rate of Rabbit was as follows; 1. In the secretion of Gastric Juice, the Juice Volume in Coptidis Rhizoma administered group in contrast to Control Group, has increased in 30mg the increasing rate 21.4%, and has decreased in 300mg the decreasing rate 113.9%. But the Juice Volume in Zingiberis Rhizoma administered group has all decreased in 12, 30, 60, 120mg, and has remarkably decreased in 60mg the decreasing rate 62.9%. 2. The Gastric Acidity in Coptidis Rhizome administered group, in contrast to Control Group, has increased in 30, and 75mg, but no significant value, and has decreased in 300mg the decreasing rate 104.7%. But the Gastric Acidity in Zingiberis Rhizoma administered group has all decreased in 12, 30, 60 120mg, and has remarkably decreased in 60mg the decreasing rate 105.6%. 3. The Pepsin out-put in Coptids Rhizoma administered group, in contrast to Control group, has increased in 30mg the increasing rate 30.3%, and has decreased in 150, 300mg, no significant value. But the Pepsin out-put in Zingiberis Rhizoma administered group has all decreased in 12, 30, 60, 120mg, and has remarkably decreased in 60mg the decreasing rate 86.4%. 4. In the movement of Intestine, the contraction Coptidis Rhizoma administered group, in contrast before the administration, has increased in 12mg, but has begun to decrease in 30mg, and has remarkably decreased in 70mg. The contraction in Zingiberis Rhizoma administered group, in contrast before the administration, has all increased in 30, 60, 120mg. 5. In Pulse Rate, the pulsation, in contrast to Control group after 60, 120 180, 240min. has decreased in Coptidis Rhizoma administered group, and has increased in Zingiberis Rhizoma administered group, but no significant value.