• The Korean Journal of Cytopathology
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• v.10 no.1
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• pp.85-89
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• 1999

An extremely unusual case of epidermoid cyst showing diffuse parakeratosis and aggressive clinical behavior is presented. A destructive bone lesion with surrounding ill-defined soft tissue lesion was found by computed tomography in a 63 year-old man complaining of painful swelling of the right buttock. He had a history of surgical excision twice for epidermoid cysts of soft tissue of the right hip during recent one year On aspiration cytology, the aspirate was highly cellular and mostly composed of desquamated nucleated squamous cells. Operation finding revealed that the iliac bone was Irregularly destroyed and filled with gray-white cheesy material and necrotic bone bedris. Adjacent gluteus muscle showed scattered gray-white lesions. The curettage specimen showed bone necrosis and desquamated squamous cells filling the marrow spaces. The lesion within muscle revealed epidermoid cyst with diffuse parakeratosis.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.6
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• pp.1381-1389
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• 1988

The heat transfer by simultaneous conduction, convection and radiation between flame and fuel surface in a thermally radiating medium is investigated theoretically. The flame and fuel surface are assumed to be diffuse, gray, infinite, isothermal, parallel surfaces separated by a finite distance. The space between the plates is supposed is formulated exactly in terms of simultaneous interior-differential equations. The numerical results reveal the effect of the system parameters on the heat transfer characteristics and the temperature distributions. The numerical results reveal that the optically thick radiating medium has a blocking effect on the total beat transfer. The temperature distributions are observed to be convex upward for an optically thick radiating medium as the alberto decreases.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.2
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• pp.331-344
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• 1987

A numerical analysis has been conducted on the interaction of the thermal radiation and natural convection in a rectangular enclosure filled with a gray fluid. P-1 approximation is adopted for the radiative transfer and its application limit is examined. Considered are the Stark number effect, the optical thickness effect and the wall emissivity effect on the flow and heat transfer characteristics. As the Stark number increase or the optical thickness decreases, the boundary layer thickness and the flow velocity increase. Transition to turbulence is retarded with the increase of the radiation effect. When the optical thickness is one, the radiation effect is negligible for the Stark numbers larger than 10.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.918-928
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• 1998

The present study was done with two aims. First, to evaluate the radiographic measurements of liver volumes in normal and hepatomegaly dogs induced by carbon tetrachloride. Second, to investigate quantitative tissue echo pattern by ultrasonography. Gray level histogram of the normal liver and the kidney were estimated with carbon tetra-chloride intoxication. In normal, r-square for liver volume to body weight was 0.93372, and this showed direct linear regression. Gray level histograms of the normal liver and the kidney were $19.150{\pm}2.490$(mean${\pm}$SD) and $13.175{\pm}2.686$(mean${\pm}$SD) respectively(p < 0.01). Liver parenchymal echogenicity was more hyperechogenic than kidney cortex echogenicity. Liver/Kidney ratio was $1.504{\pm}0.313$ and it can be used relative comparison of liver and kidney parenchymal echogenicity. In carbon-tetrachloride($CCl_4$) intoxication, changes of liver volume appeared to increase up to 24 hours after administration (p < 0.05), and decreased gradually to normal level after 2~5 days. Gray level histogram of liver parenchyma decreased up to 24hours (p < 0.01) after intoxication and then gradually increased to normal level. But that of kidney cortex had no significant change. Liver/Kidney ratio also decreased by 2 days(p < 0.01) and then gradually increased to normal level. On histopathologic features of hepatic tissues in carbon tetrachloride intoxication, both coagulative necrosis of hepatic cell and hemorrhage of centrilobular & midzonal area were identified. Conclusively, plain radiography is a useful diagnostic method for evaluating liver volume in mild hepatomegaly. Especially, it is considered that an adequate numerical processing of the liver length, depth and thoracic width and depth measurement would be helpful. Using gray level histogram, ultrasonographic evaluation was useful objective methods in early diagnosis of diffuse hepatic disease.

• Korean Journal of Medicinal Crop Science
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• v.23 no.6
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• pp.473-479
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• 2015

Background : To control ginseng gray mold, farmers have mainly used inorganic chemical based fungicides. The recent emergence of fungicide resistance has reduced the effectiveness of such control methods. Such pesticides also carry additional problems, such as diffuse pollution. Methods and Results : Six treatments of organic agricultural materials were tested for control of ginseng gray mold, CAPW (Chrysophanic acid + Phytoncide + Wood vinegar), EmEWV (Emodin + Ethanol + Wood vinegar), CEWV (Curcumin + Eugenol + Wood vinegar), Bacillus subtilis, soybean oil and sulfur. The control effect for gray mold by a single application of the agrochemical fungicide industrial Fenhexamid wettable powder (WP) was 84.4%. The control effect by CAPW, EmEWV and CEWV varied between 52.7 - 64.9%. The control effect by B. subtilis, soybean oil, and sulfur were 32.9 - 59.2%. Conclusions : In the field tests, CAPW showed the highest control effects when used before, and at first stage of disease incidence, against ginseng gray mold.

• Agricultural and Biosystems Engineering
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• v.5 no.1
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• pp.5-9
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• 2004

This study was carried out to develop methods of reducing the effect of solar illumination on pixel gray-levels of machine vision for agricultural field use. Two kinds of monochrome CCD cameras with manual and auto-iris lenses were used to take pictures within a range of 15 to 120 klux of solar illumination. A camera having more precise automatic control functions gave much better result. Four kinds of indices using pixel gray-level of the $99\%$ white DRS (diffuse reflectance standard) as a reference were tried to compensate pixel gray-levels of an image for variable illumination. Coefficients of variation of the indices within a range of illumination were used as a criterion for comparison. The study concluded that an index of (A+B)/A, where A is gray-level of the $99\%$ DRS and B is gray-level of the tested material, gave the best consistency in the range of solar illumination.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.2
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• pp.273-282
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• 1992

The purpose of this study was to propose the utility which was evaluated the digital image processing and clinical application of the videodensitomery. The experiments were performed with IBM-PC/16bit-AT compatible, video camera(CCdtr55, Sony Co., Japan), an color monitor(MultiSync 3D, NEC, Japan) providing the resolution of 512×480 and 64 levels of gray. Sylvia Image Capture Board for the ADC(analog to digital converter) was used, composed of digitized image from digital signal and the radiographic density was measured by 256 level of gray. The periapical radiograph(Ektaspeed EP-21, Kodak Co., U. S. A) which was radiographed dried human mandible by exposure condition of 70 kVp and 48 impulses, was used for primary X-ray detector. And them evaluated for digitzed image by low and high pass filtering, correlations between aluminum equivalent values and the thickness of aluminum step wedge, aluminum equivalent values of sound enamel, dentin, and alveolar bone, the range of diffuse density for gray level ranging from 0 to 255. The obtained results were as follows: 1. The edge between aluminum steps of digitized image were somewhat blurred by low pass filtering, but edge enhancement could be resulted by high pass filtering. Expecially, edge enhancement between distal root of lower left 2nd molar and alveolar lamina dura was observed. 2. The correlation between aluminum equivalent values and the thickness of aluminum step wedge was intimated, yielding the coefficient of correlation r=0.9997(p<0.00l), the regression line was described by Y=0.9699X+0.456, and coefficient of variation amounting to 1.5%. 3. The aluminum equivalent values of sound enamel, dentin, and alvolar bone were 15.41㎜, 12.48㎜, 10.35㎜, respectively. 4. The range of diffuse density for gray level ranging from 0 to 255 was wider enough than that of photodenstiometer to be within the range of 1-4.9.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.2 no.1
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• pp.1-9
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• 1992

Radiation heat transfer was calculated for initial stage of crystal growth in Czochralski crystal growth system. View factors among surface elements were calculated for the estimation of heat evolution and all the surfaces were assumed to be diffuse-gray. The values of view factors were greatly different along the position of surface elements. The dissipated amounts of heat flux from the melt surface were 3.6 times larger than those from the crystal surface at the initial stage of crystal growth and this amounts were greater when the surface elements were not considered. The trijunction part of the crystal was greatly affected by the melt surface near the crystal. Consequently radiation heat transfer between surface elements must be considered in order to correctly simulate the initial crystal growth.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.7
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• pp.956-962
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• 2022

Diffuse thyroid disease has ambiguous diagnostic criteria and many errors occur according to the subjective diagnosis of skilled practitioners. If image processing technology is applied to ultrasound images, quantitative data is extracted, and applied to a computer auxiliary diagnostic system, more accurate and political diagnosis is possible. In this paper, 19 parameters were extracted by applying the Gray level co-occurrence matrix (GLCM) algorithm to ultrasound images classified as normal, mild, and moderate in patients with thyroid disease. Using these parameters, an artificial neural network (ANN) was applied to analyze diffuse thyroid ultrasound images. The final classification rate using ANN was 96.9%. Using the results of the study, it is expected that errors caused by visual reading in the diagnosis of thyroid diseases can be reduced and used as a secondary means of diagnosing diffuse thyroid diseases.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.6
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• pp.256-260
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• 2014

This study was carried on the phenomena in reactivity with the clay surface according to the thickness of the cobalt component coating. In the coated specimen, it was observed that the cobalt component was spreaded to diffuse with a constant thickness from the surface of it and the diffusion layer at the white porcelain soil was more increased with the increase of the amount of cobalt sulfate than at the celadon porcelain one. It was evaluated that the color of the surface on the coated specimen at the white porcelain soil was changed from grayish blue to blue and the $L^*$ value was decreased from 51.78 to 37.61 and also in the case of the coated specimen in celadon porcelain soil, $L^*$ value was from 53.91 to 38.93 and the color was from dark olive gray to dark gray. The physical properties of the specimen were characterized by X-ray diffraction, Scanning electron microscope, Dilatometer, TG-DTA, UV-vis spectrophotometer and HRDPM.