• Korean Journal of Optics and Photonics
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• v.22 no.5
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• pp.239-244
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• 2011

We introduce Gaussian (or paraxial) optics that can be successfully applied to design, for use in a color analyzer, a non-imaging optical system on a measurement probe for LCD display. The color analyzer is used to decompose colored lights leaving from some measurement area on the LCD display to red, green, and blue. The color analyzer must include a condenser lens whose purpose is to gather colored lights to illuminate a small area on the sensor. In order to satisfy a reduction ratio between the measurement area and the sensing area with a non-imaging condition, a condenser lens is analytically treated by means of Gaussian optics so that good understanding of the non-imaging condenser lens is achieved as a good design is derived. As a result, the technique shows the necessity of analytical treatment in contrast to the design approach using only commercial software such as CODE-V, Light-Tools, and others. Of course, CODE V and Light-Tools are also utilized in this paper to confirm and complete the Gaussian optical design.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.3
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• pp.1114-1122
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• 1996

Variation of temperature field in a Hele-Shaw convection cell was measured by using a HSI true color image processing system and TLC(Thermochromic Liquid Crystal) solution. The relationship between the hue value of TLC color image and real temperature was obtained and this calibration result was used to measure the true temperature. The temperature field in the Hele-Shaw convection cell shows periodic characteristics of 45 sec at Ra = 9.3 * 10$\^$6/. The temperature field measurement technique developed in this study was proved to be a useful and powerful tool for analyzing the unsteady thermal fluid flows.

• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.131-136
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• 2023

We developed a method to measure the concentration of highly concentrated colored samples using color coordinates. We present a color analysis to estimate the concentration of highly concentrated binary solutions with an empirical function and apply it to estimate the kinetics of a catalytic irreversible reaction of resazurin to resorufin. The developed method enabled one to measure the concentration of solutions whose range of concentrations is nonlinear and beyond the limit of UV-vis spectroscopic measurement directly without dilution.

• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.303-308
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• 2010

Surface color is the most important quality factor for the grade evaluation of cherry tomato. Color is one of the representative indicators for the maturity which is closely related to the internal quality of cherry tomato, such as firmness, sugar content, and acidity. This study was carried out to investigate the relationship between surface color and internal quality of cherry tomatoes harvested from both hydroponic and soil culture at different ripening stages. To calculate the color values of cherry tomatoes an automatic color imaging system was constructed. A specially designed image processing algorithm for the color measurement was developed. The color values of L*, a*, b* were calculated from the initial color values of RGB and then compared with the internal quality. Statistical analyses indicated that the internal quality was more highly correlated with the surface color than size of cherry tomatoes. Color image features were also investigated to detect external damage of cherry tomatoes. The value of (R value - R mean value)/R mean value was the most effective image feature for the detection of damaged areas on the surface of cherry tomatoes. The results of this study demonstrated the feasibility of color sorting process as an alternative of the conventional drum type size sorting system for cherry tomato industry.

• Journal of the Korean Society of Costume
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• v.41
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• pp.49-62
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• 1998

This study investigates the color of daily clothes of middle era of Yi dynasty by examining the color of excavated clothing which was the real clothes in 16th and 17th centuries. The purposes of this study lie in understanding emotional feeling observed by exact measurement of the color of the excavated and devising a method of reserving the color of the excavated by inspecting the discolored color of the excavated. For this, the color difference was measured by color measuring system. Minolta Chroma-meter, and then recorded in L*a*b system. The 3-dimensional color difference was observed by analyzing these data on Methmetica and change in color with ageing was assessed by reconstructing the color by Phoposhop. The color construction of daily clothes of middle era of the Chosun Dynasty was founded on a philosophy, and it was made up of colors such as white, brown, and blue. This color construction seemed to be based on the philosophy of naturalism symbolizing surrounding nature, e.g., white symbolizes Bak-sasang(bak-philosophy) and blue implies Eumyangohangsul.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.2
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• pp.18-24
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• 2010

On-board spectrophotometer has been widely used as a non-contact and non-destructive measurement system in many fields. In this study, we evaluated the effect with respect to the light of on-board spectrophotometer based on a comparison with the standard spectrophotometer and color information coordinate system. Red, yellow, green and blue color paper, which were the standard reflective color paper and Munsell color paper, were used for experiments. In order to compare between a standard spectrophotometer system and an on-board spectrophotometer system, each color paper was measured 20 times. We concluded that it is possible to develop a system regardless the effect of light if the light was supplied consistently and a calibration was performed exactly while we applied an on-board spectrophotometer to non-contact and non-destructive measurement system.

• Journal of Radiation Protection and Research
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• v.48 no.3
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• pp.144-152
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• 2023

Background: Color texture analysis was applied as a tool for quantitative evaluation of radiation-induced skin injuries. Materials and Methods: We prospectively selected 20 breast cancer patients who underwent whole-breast radiotherapy after breast-conserving surgery. Color images of skin surfaces for irradiated breasts were obtained by using a mobile skin analyzer. The first skin measurement was performed before the first fraction of radiotherapy, and the subsequent measurement was conducted approximately 10 days after the completion of the entire series of radiotherapy sessions. For comparison, color images of the skin surface for the unirradiated breasts were measured similarly. For each color image, six co-occurrence matrices (red-green [RG], red-blue [RB], and green-blue [GB] from color channels, red [R], green [G], blue [B] from gray channels) can be generated. Four textural features (contrast, correlation, energy, and homogeneity) were calculated for each co-occurrence matrix. Finally, several statistical analyses were used to investigate the performance of the color textural parameters to objectively evaluate the radiation-induced skin damage. Results and Discussion: For the R channel from the gray channel, the differences in the values between the irradiated and unirradiated skin were larger than those of the G and B channels. In addition, for the RG and RB channels, where R was considered in the color channel, the differences were larger than those in the GB channel. When comparing the relative values between gray and color channels, the 'contrast' values for the RG and RB channels were approximately two times greater than those for the R channel for irradiated skin. In contrast, there were no noticeable differences for unirradiated skin. Conclusion: The utilization of color texture analysis has shown promising results in evaluating the severity of skin damage caused by radiation. All textural parameters of the RG and RB co-occurrence matrices could be potential indicators of the extent of skin damage caused by radiation.

• Journal of Korean society of Dental Hygiene
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• v.12 no.2
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• pp.261-273
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• 2012

Objectives : This study aims to prepare the basic data of the teeth color by measuring tooth mode using the color of the maxillary central incisor of the college students in their twenties as the dental colorimeter, and oral health and eating habit characteristics were examined. Methods : The maxillary central incisor(1 teeth) of the subjects of study as 467 students(male 89, female 378) was measured during the period from November 14, December 2 2011, so the color of total 467 teeth were examined, and oral health and eating habit characteristics were researched. Results : 1. As the results of measurement of the shade, value, hue of maxillary central incisor by the general characteristics of the subject, the major(shipbuilding information, special rehabilitation for young children) was higher at 3.3 of the shade, and the grade(1), age($$\geq_-20$$), major(beauty culture & cosmetic, occupational therapy) showed higher at +2 of the value, and the grade(1) and all major showed higher at R3 of the hue. 2. As the results of measurement of the shade, value, hue of maxillary central incisor by the oral health characteristics, the subjective teeth color(yellow) and the education of oral health(no) showed higher at 2.5 of the shade. 3. As the results of measurement of the shade, value, hue of maxillary central incisor by the eating habit characteristics of the subjects, the chocolate showed higher at 3.0 and 2.0 of the shade, and the red pepper paste showed higher at +2 and STD of the value, and the green tea showed higher at $R_3$ of the hue. Conclusions : This study demonstrates that the color of the maxillary central incisor showed differences various tendency according to the oral health and eating habit characteristics.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.1
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• pp.47-58
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• 1996

An object color can be seen differently under the various outer illuminants. However, human visual system has color constnacy that the object color can be seen constantly under the different outer illuminants. When the viewer watches TV under specific that the object color can be seen constantly under the different outer illuminants. When the viewer bathes TV under specific outer illuminants, he perceives distortes color due to the emitting specturm of outer illuminants as well as the radiation of CPT itself. Namely, when the outer illuminants such as fluorescent and incandescent lamps incident on CPT, brightness, saturation, hue, itself. Namely, when the outer iluminants such as fluorescent and incandescent lamps incident on CPT, brightness, saturation, hue, and contrast on color pictures are changend, he perceives distortedcolr fromthe original color. In this paper color enhancement algorithm based on light intensity and outer light decision funtion using RGB sensor was proposed. The implemented TV of proposed algorithm has higher visual quality at the view point of human visual system and more vivid than that ofcoventional color TV.

• 한국연소학회:학술대회논문집
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• 2004.11a
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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.