• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1069-1072
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• 2009

Field sequential display has some advantages but color breakup (CBU) is the significant problem. Many researches had introduced several methods to reduce CBU phenomenon, however there are no reliable methods to measure the degree of CBU. In this report, a novel CBU measurement technique which was based on the image processing method and subjective analysis results had proposed to evaluate the degree of CBU. Color Breakup Index (CBI) was presented to be a useful index to recognize the CBU phenomenon in the different field sequential technique displays.

• 산업경영시스템학회지
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• 제43권1호
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• pp.16-25
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• 2020

Vegetation segmentation in a field color image is a process of distinguishing vegetation objects of interests like crops and weeds from a background of soil and/or other residues. The performance of the process is crucial in automatic precision agriculture which includes weed control and crop status monitoring. To facilitate the segmentation, color indices have predominantly been used to transform the color image into its gray-scale image. A thresholding technique like the Otsu method is then applied to distinguish vegetation parts from the background. An obvious demerit of the thresholding based segmentation will be that classification of each pixel into vegetation or background is carried out solely by using the color feature of the pixel itself without taking into account color features of its neighboring pixels. This paper presents a new pixel-based segmentation method which employs a multi-layer perceptron neural network to classify the gray-scale image into vegetation and nonvegetation pixels. The input data of the neural network for each pixel are 2-dimensional gray-level values surrounding the pixel. To generate a gray-scale image from a raw RGB color image, a well-known color index called Excess Green minus Excess Red Index was used. Experimental results using 80 field images of 4 vegetation species demonstrate the superiority of the neural network to existing threshold-based segmentation methods in terms of accuracy, precision, recall, and harmonic mean.

• 한국의류산업학회지
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• 제1권3호
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• pp.275-279
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• 1999

The purpose of this study was to investigate a specific character on products of Korean cotton and American cotton with cultivated in sangju city, Korea. The results of this study were as follows: Productivity of American cotton was nine times higher than those of Korean cotton. Spinning coefficient index (SCI: 140), strength (32.6 g/tex), fiber length (1.12 inch), uniformity index (83.4%), short fiber index (6.4), color grade (21) of American cotton was superior than SCI (122), strength (27.7 g/tex), fiber length (1.02 inch), uniformity index(81.1 %), short fiber index (10.6), color grade (23) of Korean cotton. Microaire (3.5), elongation (6.9%) of Korean cotton was superior than American cotton.

• 한국재료학회지
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• 제27권6호
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• pp.312-317
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• 2017

In the construction of a white LED, the region of the red emission is a very important factor. Red light emitting materials play an important role in improving the color rendering index of commercial lighting. These materials also increase the color gamut of display products. Therefore, the development of novel phosphors with red emission and the study of color tuning are actively underway to improve product quality. In the present study, heuristic algorithms were used to search for phosphors capable of increasing the color rendering index and color gamut. Using a heuristic algorithm, the phosphors that were identified were $SrGe_4O_9:Mn^{4+}$ and $BaGe_4O_9:Mn^{4+}$. Emission spectra study confirmed that these phosphors emit light in the deep red wavelength region, which can fulfill the requirement for the improvement in color rendering index and color gamut for a white LED.

• International Journal of Advanced Culture Technology
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• 제8권3호
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• pp.123-132
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• 2020

In contemporary times, there is an increasing demand for a dedicated healthcare environment, all over the world. The main motivation for this demand is the level of awareness manifested by the users and reflected on their expectations. Therefore new research strategies and design actions are investigated in order to answer to the users' needs and to provide objective design tools for the specialist. This study continues a series of previous developments of the Healthcare Environment Color Index that should be used for public facilities in Korea and abroad. The cross-cultural approach is a new opportunity for exchanging know-how and for testing and calibrating the perception of the users on the color index. The gathering of results was made based on the online survey provided in this phase in English version for the Romanian users. The survey was intended as an objective mean of research and an efficient way of disseminating information on the subject thus contributing to increasing the level of awareness of the users. A total of 86 Romanian and 89 Koreans with valid answers took part in the survey. Comparative visualizations of the results showed significant similarities concerning the patterns of color preferences but also cultural and emotional differences. As a result both categories of users proved to be aware of the relation between healthcare environment color and its effects on health. They also showed a common understanding on the potential of the color index. As a result the most appealing colors to be applied to the healthcare environment were the series G and B, and the most effective ones were proved to be the ranges of high lightness and low saturation but also the medium high lightness and medium saturation. Both the similarities and the differences of choice between Romanians and Koreans show that cultural and emotional differences of color recognition are important and that should be taken into consideration in design, in order to generate an inclusive and efficient healthcare environment.

• 한국염색가공학회지
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• 제25권4호
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• pp.241-246
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• 2013

The color properties of a white or nearly colorless fabric are represented by whiteness index (WI) or yellowness index (YI). These two indexes relate to a white fabric's color quality. The purpose of this study was to identify the properties of WI and YI on the CIELAB through the simulations of estimation data for a systemization of color quality control. The results indicated that the relationship between WI and YI was a negative correlation, however the coefficients of correlation function between WI and YI were depended on hue. There were two hue transition points of the rate of changes in WI and YI. These hue transition points were the reference points to divide the hue contribution to WI and YI. These points were not the point of h=0 and h=180 and asymmetric. In addition, where the colors were same distance from the white point on the CIELAB, the rate of changes in WI and YI by ${\Delta}$Ew were depending on hue. Specifically, when WI decreased, YI of reddish and yellowish tinted colors decreased more than bluish tinted colors.

• 조명전기설비학회논문지
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• 제28권3호
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• pp.1-6
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• 2014

We measured color rendering index(CRI) of a LED lamp for lighting for aging-time. We chose bulb type white LED lamp six samples and halogen lamp one sample and applied 220V, 60Hz to all the samples for 1,000hours at ordinary temperature. The CRI was measured every 20hours and the CRI change of the LED lamp was compared with the halogen lamp's CRI change. As time goes, efficiency of the halogen lamp decreased and the CRI maintained uniformly. The other hand, efficiency of the LED lamp decreased but the CRI increased. The CRI of the LED lamp has been stabilized since 600hours. The CRI change of the LED lamp was analyzed with a spectrum, color coordinate and color temperature.

• 한국안광학회지
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• 제5권2호
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• pp.151-155
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• 2000

칼라 렌즈 제작시 착색 시간에 따른 분광반사율을 측정하여 렌즈표면의 굴절률을 계산하였다. 착색 시간이 길수록 반사율과 굴절률은 커진다. 렌즈 표면에 착색물질이 포화상태가 될 때까지 굴절률은 시간에 따라 증가하였다. 시간에 따른 blue color 렌즈의 굴절률 변화 곡선은 Boltzmann 성장곡선을 따르며, 이때 $n_{min}$은 1.482. $n_{max}$는 1.497. $t_c=11.53$ 그리고 $d_0$ 등의 2.287 등의 parameter 값을 얻었다.

• 정보과학회 논문지
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• 제42권10호
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• pp.1294-1302
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• 2015

현재까지 인간 시각 체계를 정확하게 반영하기 위한 이미지 평가 기법에 대한 연구가 많이 이루어져 오고 있다. SSIM은 인간의 시각 체계가 이미지의 구조적 정보에 예민하다는 점을 이용하여 구조적 정보를 이용하여 이미지를 평가하는 대표적인 인간 시각 체계를 만족시키는 평가 기법이다. 하지만 SSIM은 이미지의 색 차이를 반영하지 못하는 문제가 있다. 이러한 문제를 해결하기 위해, HSI 색 공간을 활용한 SHSIM 기법이 제안되었으나 두 컬러 이미지 간 인지적 색 차이를 충분히 반영하지는 못하고 있다. 본 논문에서는 CIE Lab 색 공간을 도입하여 대응 되는 픽셀들의 인지적 색 차이를 계산하여 이미지 평가에 활용하는 방법을 제안한다. 그리고 연구를 더 확장하여, SVM 분류기를 활용하여 왜곡 종류에 따라 최적의 평가 수식을 적용하는 최적화 시스템을 제안한다. 제안하는 기법을 평가하기 위해, 이미지 평가분야에서 가장 많이 알려진 LIVE 데이터베이스를 사용하였으며 네 종류의 평가 기준들을 이용하였다. 실험 결과에서는 제안하는 기법이 다른 기법들보다 인간 시각 체계와 더 상관성이 높다는 것을 보여준다.

• International Journal of Advanced Culture Technology
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• 제9권3호
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• pp.131-141
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• 2021

The present study is following a series of research investigations on design resources coming from collected data referring to users' awareness and preferences. The aim of this research is to test the Healthcare Environmental Color Index as a basis for practitioners in the field of healthcare design. An array of color samples selected from previous research, have been presented to the respondents via an online survey, in order to identify the preferences of the two groups on the relation between environmental color and health. As a result of the first experiment and through the comparison of processed data, the maximum percentage of respondents from each group is validating the relation between environmental color and health. For the second experiment we intend to highlight the patterns of color preferences for each group, and thus to test the color samples healing function. The compared data also showed a higher awareness of Koreans than Romanians on the potential of color applied to healing environment. Last but not least in the third experiment we show the top five color samples preferred by each group. It is significant that the comparison of the results validated once more some of our previous findings related to the healthcare environment, such as: the general preference for the green hue (associated to fatigue relax according to color psychology) and the blue hue (sedation release effect) but also the yellow hue - associated to bright energy. Three out of the top five preferred color samples have been identical to both groups while the other two samples have shown characteristic variations. These results show that similarities are strong and can be used in a glocal design strategy as an accessible tool for any practitioner. Based on the Healthcare Environmental Color Index and users' preferences analysis, a new design culture for healthcare can be established and developed.