• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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• pp.124-129
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• 2004

The ratio pyrometry has been investigated experimentally for the measurement of soot particle temperatures in a diffusion flame. A tungsten lamp calibration system was constructed and used in order to calibrate the ratio pyrometry and two-color pyrometry using a KL-factor method. Once the ratio pyrometry is properly calibrated, temperatures measured using a ratio pyrometry were virtually identical to those obtained from a KL-factor method. The effect of soot volume fraction on temperature measurement was almost negligible, and therefore, the ratio pyrometry could provide the useful temperature information of sooting flames. The potential application of a ratio pyrometry to a 2-D temperature measurement without sacrificing the accuracy was demonstrated.

• 전기학회논문지
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• 제63권8호
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• pp.1121-1127
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• 2014

Many studies have been done to measure and analyze color for various purposes. Visual assessment has lack of objectivity and the equipment for color measurement is very expensive. In this study, we developed a device for quantitative analysis of the color using optical elements. With the color sensor, the ratio of RGB was calculated by measuring the light intensity that is reflected from an object. Inverse transformation of optical signal was performed to detect the color density. The suggested color analyzer can detect color information as well as sample concentration. Results of this study are expected to be used in various medical fields such as pH indicator and urine analysis.

• 한국염색가공학회지
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• 제18권5호
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• pp.72-79
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• 2006

There are many discrepancies between visually perceived color-difference and that which is quantified from an instrumental measurement when dark color samples are measured in the textile industry. The samples were prepared to represent these dark shades and the values of the instrumental results from conventional color-difference formulae(CIELAB, CMC, BFD II, CIE94, LCD99 and CIEDE2000). Those of visual assessment were compared. The experimental results show that the CIELAB formula gives the best performance over other formulae, and the CIEDE2000 formula for the color-difference according to chroma presents the worst performance. Therefore, we can say that the problems in color matching of dark shades are caused by imperfect formula, because the results obtained from a color-difference formulae are different and the CMC which is used as a standard color-difference formula in the textile industry is not correct. So, a revised color-difference formula is proposed in this study, to account for these problems.

• 조명전기설비학회논문지
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• 제26권11호
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• pp.9-19
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• 2012

The purpose of this study is to present the direction of LED lighting development to give people a comfortable feeling. For about 2 years, the database of daylighting color has been built by daylighting measurement and analysing hourly, monthly and seasonal change in daylighting colors. Finally, changes of color coordinates were drawn as a graph and it presented as the LED lighting color development indicator through the relationship with Plankian locus. This methodology is expected to contribute to the development fields of the LED lighting color.

• Industrial Engineering and Management Systems
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• 제3권1호
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• pp.63-70
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• 2004

In this paper, we consider the adjustment of convergence on Color Display Tube (CDT). Convergence is a measure of how well the red, green and blue beams are physically aligned with each other to strike the same area on the screen. When misconvergence (convergence error) occurs, one way of compensating it is to attach several ferrite sheets on the inner part of Deflection Yoke (DY). We suggest an optimization model of misconvergence compensation process and report test results for 81 DY samples. As a result, more than 90% of the samples could be made to satisfy the required convergence criteria.

• 대한한의학회지
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• 제37권3호
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• pp.27-38
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• 2016

Objectives: According to Korean Medicine theory, the skin color of LU10 serves as a diagnostic clue to dyspeptic symptoms. The aims of this study were (1) to find the difference of skin color in LU10 region between functional dyspepsia (FD) and healthy control (HC) and (2) to examine the relationship between LU10 skin color parameters and dyspeptic symptoms. Methods: 39 participants (29 FD and 10 HC) have participated in this study. They were asked to complete gastrointestinal scale (GIS), gastrointestinal symptom rating scale (GSRS), Nepean dyspepsia index (NDI), functional dyspepsia-related quality of life (FD-QoL), visual analogue scale (VAS) for dyspeptic symptoms, food retention questionnaire (FRQ) and cold heat questionnaire (CHQ). $L^*$ (luminance), $a^*$ (red-green balance) and $b^*$ (yellow-blue balance) values of LU10 region were calculated through digital images of the participant's hand. Then we evaluated test-retest reliability of $L^*$, $a^*$ and $b^*$ values of LU10 region. Additionally, we compared $L^*$, $a^*$ and $b^*$ values of LU10 between FD and HC, and examined the relationship between LU10 color parameters and seven questionnaires scores. Results: Only $L^*$ values in LU10 region were significantly higher in FD compared with HC. GIS scores and the subset scores of NDI had a positive correlation with $L^*$ values significantly. Correlation coefficients of test-retest reliability of skin color measurement of LU10 ranged from 0.871 to 0.936 representing very strongly statistically significant (P<0.001). Conclusions: We confirmed the difference of skin color in LU10 region between FD and HC, and relationship between LU10 skin color parameters and dyspeptic symptoms.

• Journal of Information Display
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• 제11권1호
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• pp.17-20
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• 2010

With the increasing demand for a better FPD image quality, better evaluation metrics and advanced display quality measurement methods are required to meet these needs. There are many measurement methods for evaluating the viewing angle of various display devices, but these methods, which include luminance drop, color shift, and contrast ratio decrease, are imperfect considering that human perception does not completely correlate to them. In this paper, a new method of measuring the perceptual angle of FPDs is proposed, considering human visual perception, which uses the color space of the color appearance model.

• 한국멀티미디어학회논문지
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• 제14권4호
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• pp.481-493
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• 2011

모바일기기가 발달함에 따라 핸드폰에 수많은 기능들이 탑재되고 있다. 영상 통화 기능도 그 중 하나이다. 본 논문에서는 화자와 스마트폰 사이의 거리를 측정하기 위한 다중 색좌표계와 다중 임계치를 사용하는 방법을 제시한다. 첫 번째로 피부색의 색상정보에 근거하여 얼굴영역을 검출한다. 두 번째로 검출된 얼굴영역의 크기를 이용하여 스마트폰과 화자 사이의 거리를 측정한다. 특히 본 논문에서 제시하는 얼굴영역 검출 알고리즘 개발에 있어 고려한 점은 스마트폰의 기본기능과 함께 실시간으로 처리가 가능할 정도로 연산량이 적어야 하며, 움직임이 많은 핸드폰의 특성상 프레임과 프레임 사이의 움직임과 조명 및 배경에 따라 검출된 얼굴 영역이 급격히 변화하는 문제를 해결할 수 있는 얼굴영역 검출 알고리즘을 개발하고자 하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.979-982
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• 2009

With increasing demand for better FPD image quality, better evaluation metrics and advanced display quality measurement methods are required to meet these needs. There are many measurement methods to evaluate viewing angle of the various different display devices. However, these methods, which include luminance drop, color shift, and contrast ratio decrease, are imperfect considering that human perception does not completely correlate to these methods. In this paper, we propose a new method for measuring perceptual angle of FPDs considering human visual perception, which uses color space of the color appearance model.

• The Journal of Advanced Prosthodontics
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• 제6권4호
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• pp.309-316
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• 2014

PURPOSE. The color of the ceramic restorations is affected by various factors such as brand, thickness of the layered the ceramic, condensation techniques, smoothness of surface, number of firings, firing temperature and thickness of dentin. The aim of this study was to evaluate the color change and surface roughness in dental porcelain with different thicknesses during repeated firings. MATERIALS AND METHODS. Disc-shaped (N=21) metal-ceramic samples (IPS Classic; Ivoclar Vivadent; Shaar, Liechtenstein) with different thickness were exposed to repeated firings. Color measurement of the samples was made using a colorimeter and profilometer was used to determine surface roughness. ANOVA and Tukey tests with repeated measurements were used for statistical analysis. RESULTS. The total thickness of the ceramics which is less than 2 mm significantly have detrimental effect on the surface properties and color of porcelains during firings (P<.05). CONCLUSION. Repeated firings have effects on the color change and surface roughness of the dental ceramics and should be avoided.