• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.410-411
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• 2011

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.10
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• pp.1955-1962
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• 1992

The purpose of this study is to identify the radiative heat transfer augmentation by a coaxial cylinder introduced in the infinite cylindrical pipe enclosing a participating gas. The gas is either a mixture of water vapor and carbon dioxide or gray. The gas is assumed to be homogeneous at a constant temperature, and has a refractive index of unity. All of the surfaces are opaque and gray, diffusely emitting and reflecting at a constant temperature, The effect of system diameter, diameter ratio, wall emittances, gas and surface temperatures, mixture component on heat transfer augmentation are studied by using the zone method with participating gas radiative properties evaluated from the weighted sum of gray gases model. From the radiative equilibrium condition, the installed wall temperature is formulated and calculated by the iteration method. If the medium is a gray gas, the augmentation observed are negligible. For the range of values studied for a real gas, if the system diameter is larger than about 0.1m the augmentation parameter increases up to about 1.2 as the system diameter increases. The augmentation parameter have a maximum value at a certain diameter ratio. The augmentation parameters decreases as the emittance of the installed wall decreases. If the gas temperature is higher than about 1273 k, the augmentation parameter decreases as the gas temperature increases.

• The Korean Journal of Cytopathology
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• v.7 no.1
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• pp.12-22
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• 1996

Fine needle aspiration(FNA) has been quite successful in identifying benign and malignant breast lesions, but a "gray zone" exists. A total of 697 FNAs of breast were performed at Korea Cancer Center Hospital for a period of one year. One hundred and eleven of the 697 FNAs were diagnosed as atypical or suspicious for malignancy. Among them, we reviewed 74 FNAs, un which histologic diagnoses were made, and applied cytologic grading system proposed by Masood et al (1990) to evaluate the usefulness of this system in minimizing the size of gray zone. Technical problem was responsible for equivocal diagnoses in 19 FNAs Of the remaining 55 FNAs, 18 were benign and 37 were malignant. Among benign conditions, fibroadenoma(5 cases) and fibrocystic disease with fibroadenomatous feature(3 cases) constituted the largest groups. The majority of malignant conditions were infiltrating ductal carcinoma(29 cases), however, those low grade carcinomas Including tubular carcinoma(3 oases), cribriform carcinoma(2 cases), and mucinous carcinoma(2 cases) occupied a relatively large proportion Cytologic grading system was quite useful in minimizing the size of gray lone. The scores of 27 out of 29 usual infiltrating ductal carcinomas belonged to the group of cytologic malignancy, how-ever, only 2 out of 7 low grade carcinomas got scores of malignancy FNA from fibroadenoma or fibrocystic disease with fibroadenomatous features showed a tendency toward high scores. Experience of the cytopathologist and familiarity with cytologic alteration in breast disease cannot be overemphasized.

• Journal of the Korean Society for Heat Treatment
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• v.9 no.4
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• pp.271-280
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• 1996

This study has been performed to investigate into some effects of power density and traverse speed of laser beam on optical microstructure, hardness and wear characteristics of gray cast iron treated by laser surface hardening technique. Optical micrograph has shown that large martensite and a small amount of retained austenite appear in outermost surface layer with fine martensite in inside hardened zone. Hardness measurements have revealed that the range of maximun hardness value is $Hv=650{\pm}15$ and as the power density increases and the traverse speed decreses, the depth of hardened zone increases due to as increase in input power density. Wear test has exhibited that wear rasistance of laser surface hardened specimen is superier compared to that of untreated specimen under the condition of same load at a given sliding distance, showing that absorption results of an wxidized substance due to a heavy abrasion appear in untreated specimen. The amount of weight loss of laser surface hardened specimen with respect to sliding distance at a given load decreses with increasing traverse speed at a given power density and with increasing power density at a given traverse speed.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.435-439
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• 1994

The present observation was focussed mainly on the histopathological and immunohistochemical finding of the tumor developing from the outside of rat uterus wall. In gross finding, this tumor were a oval form mass and 0.75cm and 1cm in greatest demension. The sectioned surface showed uniform, solid, gray-white. In histopathological finding, the tumor showed the form of lymphoid nodule-like structure and was composed of the cells with karryorrhexis, karyolysis and necrosis in the central zone, mature cells in the paracentral zone, and concentric layers of compressed, flattened and atrophied smooth muscle fibers by the proliferating of the cells closely resembling endometrial stromal ells in the peripheral zone and a few smaller nodule-like structure in certain areas of the peripheral zone. In immunohistochemical observations, the proliferating cells presents only among the concentric layers of the smooth muscle fibers in the peripheral zone. Labeling index of proliferating cells in the peripheral zone was $4.34{\pm}1.28%$. These tumor cells did not metastasized in another orgns and labeling index was low, So it was concluded that this tumor was benign stomal sarcoma.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.3 s.39
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• pp.115-135
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• 1990

The purpose of this study was to suggest an improvement proposal for colors in urban environment with special regard to the surface color and their situations of apartment buildings in Seoul. For this goal, 167 cases of different color types of apartment buildings were surveyed. And, the survey was performed in the view of color by areas, by localtion, by builder, by paint year, by built year, by appearance of building, and by surface texture to prove the influencing factors on the surface colors. These collected data analyzed and compared with the existing studies to find out the changing trend of colors. The results are as follows : 1) The use of neutral gray($26.4{\%}$) and warm color(YR, Y, GY; 56.4%) were dominant and the usage trend of higher 'value'(87.4%) and lower 'saturation'(73.0%) was obvious. Especially, the use of PB and P was noticeable. 2) In comparing the existing studies, the changing trend in the surface color pattern was found. That is, neutral gray was used dominantly in 1970's, warm color(YR, Y)in the middle of 1980's. In the end of 1980's, warm color were also used dominantly same as before and GY, PB, P were used noticeably with some rising tendency of higher 'value' and lower 'saturation' was obvious. 3) The results of analysis by localtion shows that the different color groups might exist in Seoul city. Neutral gray and YR were dominant in zone I. Warm colors(YR, Y, GY)were prevailed in zone II, III, IV. In zone V, many colors were evenly used. In zone VI, middle values at warm color were dominant. Progressively, these color groups with further study could be considered in the color management in urban environment possibly. 4) Surface color of apartment buildings were different from their builders. 5) Concerned with the painted year, the use of higher 'value' and lower 'saturation' was increased gradually with the change of times. 6) the analysis by the built year revealed that the 'value' of surface colors on the old buildings was lower than that of the new ones. 7) The 'value' of colors on the surface with texture was higher than that of the surface without texture. 8) In the combination of two colors, the use of 'value' with difference at the same 'hue' was found harmonions in many cases, but the 'saturation' in usage was included in the ambiguity (Moon & Spencer's term). The ambiguity in color harmony should be improved in the near future.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.127-132
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• 2012

This study discusses photoresist forming using a composite grayscale to fabricate a Fresnel lens. Grayscale lithography is a common production method used to facilitate the forming of lenses with different curvatures and depths. However, this approach is time consuming and expensive. This study proposes a method for overcoming these obstacles by integrating a digital micromirror device and microscope to supplant the traditional physical grayscale mask. This approach provides a simple and practical maskless optical lithography system. According to the results, the two adjacent grayscales displayed substantial differences between the high grayscale and influence the low grayscale that ultimately affected photoresist formation. Furthermore, we show that change of up to 150% in the slope can be achieved by changing the grayscale gradient in the central zone and the ring profile. The results of the optical experiment show a focus change with different gray gradients.

• Journal of The Geomorphological Association of Korea
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• v.23 no.2
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• pp.1-13
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• 2016

This study analyzed pollen compositions in archaeological site on alluvial plain of Taehwa River, Taehwa-dong, Ulsan-si vegetational and environmental change during 6,200~3,000 yr BP. The results consist upward of Pollen Zone I (Inner Bay environment), Pollen Zone II (Quercus-Alnus stage) and Pollen Zone III (Alnus stage). The pollen grains of Fagopyrum and reddish gray silty horizon including artifacts of the Bronze Age suggest that there was cultivation on dry-field around the study site, although it is not sure that there was paddy-field cultivation.

• Journal of Welding and Joining
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• v.8 no.4
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• pp.35-45
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• 1990

Casting are widely used nodays as complicated and diversified forming materials due to its superior castability. However the welding of cast iron has not been accompaniced satisfactory resulting in an microstructure change happened in the heat affected zone (HAZ), especially the graphite are formed and shaped consecutively in the area and it has great impact on the crack occuring and growth together with martensite forming in this area. It case of gray cast iron welding, it is required for pre-heat treatment or specific welding consumables to restrain forming the martensite in the HAZ. In this study, by applying the plasma surface overlaid welding. Fe-Mn-Al steel powder has been used for improvement of anti-crackability in the HAZ and much attention has been paid to establish the overlaid welding method for gray cast iron so that optimum welding conditions may prevent the cracking. With our experiments, we have found that to prevent defects which may occur in the HAZ, the overlaid welding technique for gray cast iron has been developed.

• Animal Systematics, Evolution and Diversity
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• v.34 no.1
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• pp.64-68
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• 2018

The genus Callochiton Gray, 1847 is small to medium sized chiton (up to $55{\times}36mm$ in size) and includes approximately 30 species worldwide, most of which are found on hard substrata in subtidal zone. To date, only three species of Callochiton Gray, 1847 have been reported in Japan. In this study, we found C. foveolatus(Is. Taki, 1938) as first record of the family Callochitonidae Plate, 1901 in Korea and its morphological features were described and compared with other northwestern Pacific species. In addition, the partial fragment of mitochondrial DNA cytochrome c oxidase subunit I sequences of C. foveolatus was determined as DNA barcoding record and compared with other congeneric species.