• Journal of the Korean Wood Science and Technology
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• 제40권6호
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• pp.406-417
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• 2012

In this study, eco-friendly hybrid composite boards were manufactured from green tea, three kinds of charcoals and wood fiber for developing interior materials to reinforce the functionalities such as the deodorization and the absorbability on the green tea-wood fiber hybrid boards in the previous researches. The effects of kind of raw materials and the component ratio of raw materials on dimensional stability, deodorization and emission of formaldehyde were investigated. Thickness swelling of the hybrid composite boards increased with increasing of component ratio of green tea and charcoals, but the values were markedly lower than that of Korean standard (KS) for commercial medium density fiber board (MDF), except for hybrid composite boards composed of greed tea, activated charcoal and wood fiber. Reduction rate of ammonia gas for the hybrid composite boards composed of green tea, activated charcoal and wood fiber showed a high value of 96% after 30 minute from the beginning of the test, and the other hybrid boards also showed a high value of about 95% after one hour. Emission amount of formaldehyde was similar to that of $E_0$ grade in case of using $E_1$ grade urea resin, and was similar to that of super $E_0$ grade in case of using $E_0$ grade urea resin.

• Journal of the Korean School Mathematics Society
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• 제17권4호
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• pp.771-804
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• 2014

The concept of the center of gravity is presently being introduced in elementary school curriculums and is broadly applied to Mathematics, Physics, and the Engineering field in University education which are mostly theoretical classes much separated from actual life in the practical educational field. In 2013, ${\bigcirc}{\bigcirc}$ University of Science and Gifted Education, had developed the multidisciplinary approach program of verifying the center of gravity for gifted students, but this program was reconstructed and applied to ordinary students and the effectiveness was analyzed to lay the foundation and generalize this convergence education. Including experiments for verifying the center of gravity in an object with a hollow interior and the existence of a center of gravity outside an object, I proposed realizing the calculations by considering the weight of the lever, the Principle of the lever being a core factor when finding the center of gravity. We altered the existing 8 step program to a 4 step program for the told 65 students from elementary, Junior and High School students, letting them freely select the class lecture by themselves. The analysis attained from surveys, debates and interviews showed that by precise error analysis, students achieved a higher success experience, showing us the importance of the development of a new convergence program.

• Journal of the Korea Institute of Building Construction
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• 제10권5호
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• pp.113-119
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• 2010

Fire resistance and field tests for high-strength concrete(HSC) of 80MPa were carried out to evaluate whether or not it shows the same material properties even in the field condition of being mass-produced and supplied. As a result, it was found that fire resistant HSCs containing composite fiber(NY, PP) of 0.075% have great resistance to fire and spalling. In the field test, before the pumping air contents, slump flow, U-box, L-flow, compressive strength, gap of hydration temperature of interior and exterior of specimen and placing ratio per hour satisfied the required properties of HSC. However, after the pumping of HSC, as slump flow and L-flow were slightly less than required criterion, they need to be improved. In terms of hydration temperature of HSC, it was found to satisfy the related criterion. Packing ability as well as placing ratio per hour of HSC, which was about $44m^3$, show outstanding results. If slump flow of developed ternary HSC is improved after the pumping it can be useful for the construction of high-rise buildings.

• Journal of Conservation Science
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• 제29권4호
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• pp.437-444
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• 2013

We studied for the chemical characterizations of the charred residues obtained from the ancient potteries in the Proto-Three Kingdom period from archaeological sites in Joong-do, Chuncheon. Organic components of the charred residues were extracted and analysed using mass spectrometry and infrared spectroscopy. Lipid profiles from these samples were not identified in gas chromatography-mass spectrometry. Bulk stable isotope analyses of charred residues was used to infer an average values of the foods prepared. The average carbon isotope values (${\delta}^{13}C$) of the residues are $-14.7{\pm}2.8$‰ (ranging from -8.7‰ to -18.4‰, n=9), and nitrogen isotope values (${\delta}^{15}N$) are $6.2{\pm}1.1$‰ (ranging from -4.4‰ to -7.6‰, n=9). This is the first approach to analyse charred residues using stable isotopic method in Korea. Charred food residues on the interior surface of archaeological pottery can provide valuable information about pottery use and dietary habits of its population.

• Journal of Animal Science and Technology
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• 제52권3호
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• pp.237-244
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• 2010

In order to investigate the physiological properties of velvet antler of elk (Cervus e. canadensis) raised in Korea, antlers (n=378) were collected from deer in 8 provinces including Gyeonggi-do (n=53), Gangwon-do (n=49), Chungcheongbuk-do (n=62), Chungcheongnam-do (n=68), Jeollabuk-do (n=52), Jeollanam-do (n=15), Gyeongsangbuk-do (n=30) and Gyeongsangnam-do (n=49). The exterior characteristics (weight, length, girth and crown) of all antlers were measured, and 18 antler samples were randomly selected for measurement of interior characteristics such as specific gravity, capacity and diameter of cross section. The mean antler weight, length of the main beam and mean length of upper section were $4.87{\pm}1.79\;kg$, $83.7{\pm}13.2\;cm$ and $40.6{\pm}11.4\;cm$, respectively. Mean girth of the top, middle and base of the main beam were $27.1{\pm}5.9\;cm$, $22.1{\pm}3.6\;cm$ and $22.9{\pm}3.6\;cm$ respectively, indicating a slight narrowing in the middle of the antler. In each of the tines, the girth at the base was markedly thicker compared to the top. The depth of the crown at the top of the antler, and the average number of crowns and tines were $14.1{\pm}7.0\;cm$, $2.1{\pm}0.6$ and $3.0{\pm}0.5$, respectively. Although there was no significant difference in mean specific gravity between top and base, mean specific gravity of main beam tended to increase from top to base of the antler with decreasing capacity. Additionally, the inner diameter of the base of the antler was significantly reduced compared to that of the top, indicating a greater integumental thickening due to mineralization. Information on the morphological and physiological properties of elk antlers is scarce. Therefore, these results may be useful in providing basic information for the physiological properties of antler, and encourage further studies on antler morphology in other deer species showing species specific differences.

• Applied Microscopy
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• 제40권2호
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• pp.109-116
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• 2010

Morphology and microstructure of the suction trap in aquatic Utricularia japonica were examined using scanning electron microscopy. Branched stems bear numerous suction traps without root formation. The traps are derived axillary from the node, and their antennae and appendages extend in a peculiar fashion. The trap walls are thin, two-celled, parenchyma tissue and simple, small glands are scattered in both internal and external surface of the trap. The entrance of the trap is surrounded by one pair of dorsal antennae and ventral appendages, where the former guides the prey to the entrance. Trap door is situated below the entrance and numerous sessile and stalked capitate trichomes cover the entrance and even on the door surface. The capitate trichomes are secretory, but four trigger hairs formed on the central areas of the door are not. They are believed to function in activating and tripping the trap door. A specialized region of the threshold come in contact with the lower portion of the door upon closing. The secretory capitate trichomes near this region are responsible for producing and secreting a mucilage-like substance which composes the velum. Two-armed bifid glands are located in the interior side of the threshold, while four-armed quadrifid glands are considerably numerous occurring over the entire inner trap wall. Bifid and quadrifid glands develop semi-spherical basal cells that connect them to the inner wall surface. Antennae, trigger hairs, capitate trichomes, bifid and quadrifid glands are more important structures in the carnivory of U. japonica.

• Journal of the Korean Solar Energy Society
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• 제34권5호
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• pp.89-99
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• 2014

The determination of the solar and thermal performance of fenestration is required for the evaluation of fenestration energy performance, estimating building load. Presently, there exist several methods for determining the thermal transmission(U-value) and solar heat gain coefficient (SHGC) of fenestration system. These method are commonly grouped under calculation or experimental methods. While U-value testing and calculation methods have been long established, SHGC has been evaluated only by the method of calculation under the lack of any established testing method. However, it is difficult to assess the exact SHGC for various types of fenestration with sun-shading or other solar control systems. The purpose of this study was to evaluate the effect of interior venetian blind and roll screen on the SHGC of glazing system. SHGC has been evaluated by the KS L 9107 test method and exiting calculation method for precise comparison of the energy performances of various shading devices. In this research, the test sample consists of three different types of double glazing unit with venetian blind and roll screen. Slat angles of venetian blind were changed to $-45^{\circ}$, $0^{\circ}$, and$-45^{\circ}$. For the roll screen, measurements were taken with the roll screen in the closed position. In result, the venetian blind reduced SHGC by 21.2~28.4% at $45^{\circ}$, when compared to the double glazing unit. The roll screen reduced SHGC by 34.4~41.7% at closed. The differences between the measured and calculated SHGC were found to range between 0.001(0.2%) and 0.047(11.1%) for all test cases. For the cases of venetian blind $-45^{\circ}$, $0^{\circ}$ and $45^{\circ}$, the deviation ratio were 3.6~9.8%, 1.1~2.6%, 4.2~11.1%, respectively. For the case of roll screen, the deviation ratio were 4.1~5.7%.

• Journal of the Korea Concrete Institute
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• 제22권2호
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• pp.209-217
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• 2010

Recently, some mathematical models for the prediction on progress of carbonation of concrete were reported. These models take account for $CO_2$ diffusion and chemical reaction between $Ca(OH)_2$ and $CO_2$. Based on the assumption that $CO_2$ diffuses in the carbonation zone and reacts with $Ca(OH)_2$ at the outer face of carbonation zone and non-carbonation zone. In this study, a mathematical model to predict the progress of carbonation of concrete has been established based on the reducing concentration of $Ca(OH)_2$ in the carbonation progress zone, where $Ca(OH)_2$ reacts with $CO_2$ and $Ca(OH)_2$ and $CaCO_3$ coexist. Also, the prediction model of carbonation progress rate of concrete using the air permeability coefficient regarding to $CO_2$ diffusion is developed. As a result of this study, an expression, the model equation is obtained for the prediction of carbonation based on the time and interaction velocity between $CO_2$ and Ca(OH)$_2$ dependent air permeability coefficient. The prediction by the model satisfied the experimental data of the accelerated carbonation for painted concrete. Consequently, the model can predict the rate of carbonation and the potential service life of concrete structure exposed to atmosphere.

• Imaging Science in Dentistry
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• 제39권3호
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• pp.149-156
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• 2009

Purpose : The purpose of this study was to develop a stent-based image guided surgery system and to apply it to oral and maxillofacial surgeries for anatomically complex sites. Materials and Methods : We devised a patient-specific stent for patient-to-image registration and navigation. Three-dimensional positions of the reference probe and the tool probe were tracked by an optical camera system and the relative position of the handpiece drill tip to the reference probe was monitored continuously on the monitor of a PC. Using 8 landmarks for measuring accuracy, the spatial discrepancy between CT image coordinate and physical coordinate was calculated for testing the normality. Results : The accuracy over 8 anatomical landmarks showed an overall mean of $0.56{\pm}0.16\;mm$. The developed system was applied to a surgery for a vertical alveolar bone augmentation in right mandibular posterior area and possible interior alveolar nerve injury case of an impacted third molar. The developed system provided continuous monitoring of invisible anatomical structures during operation and 3D information for operation sites. The clinical challenge showed sufficient accuracy and availability of anatomically complex operation sites. Conclusion : The developed system showed sufficient accuracy and availability in oral and maxillofacial surgeries for anatomically complex sites.

• Archives of design research
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• 제19권2호
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• pp.207-216
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• 2006

Even though the notion exists that wall paper has got a short durability for interior decoration in terms of paper's nature, it can be the most important element among the modern dosing wall papering because of the variation of the walls visual effect. Wall paper hasn't been preserved well according to the paper's character and official records haven't been done well. So, by studying a case in which a room is maintained well, seeing various commercial samples which were used for an advertisement and reading several booklets it is possible to study historical evidence. In regard to wall paper and Papering. data, the commercial historic nature of the traditional wall papering has been recognized again in order to study the root of the technical and commercial background. In theory, the historic background research of traditional wall paper in the past is said to have established its theoretical system and the development of modern wall papering in the middle of Britain in 18th century. Through the theoretical study of wall papering, the following things have been researched: handling don the method of the traditional wall papering and lining paper, stylization of pattern by using the method of continual linking, subdivision of commercial cost and specialization of wallpaper, handing down the past traditional adhesion method, the origin of string wallpaper, utility of traditional wallpaper and its various abilities, the change from the face to face linking to duplicated linking, the development of DIY products by women's wallpaper selections. Put against other materials, wallpaper remains the most popular and preferable product for managing a wall and provides a decorative, wall dosing technique. This study can estimate the source of wallpapering history in order to create a systemic approach towards the future's wallpaper industry. This is very important data in order to establish a theoretical system of traditional wallpapering according to its historical research about wallpapering skills and its commercial aspect.