• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.14-17
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• 1995

This study is designed for producing and analyzing the structure application properties of the ready mixed concrete of specified concrete strength about 400kg/$\textrm{cm}^2$ in the batcher plant. And this part is designed for analyzing to the slump, slump flow, air content and unit weight in fresh state. By the test results of fresh concrete state, the slump, slump flow and air content are decreased, but unit weight is increased while open time is passed.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.93-96
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• 2006

To investigate the properties of high flowing concrete with fly ash and crushed sand for CFT structure, many batches were performed by a trial-error method and the results were analyzed by SPSS software program. In the experiment W/B was set up as 0.25 and the variables were a substitution ratio of fly ash, a blend ratio of crushed sand and the ages of specimens (3, 7, 28 days). The results of this study are summarized as the follows; 1) The increase of the substitution ratio of fly ash, the decrease of dosage of SP and the increase of dosage of AEA due to very fine sphere particle of fly ash. 2) The increase of the blend ratio of crushed sand, the increase of dosage of S/a and water content related with viscosity. 3) Made the high flowing concrete, the increase S/a and the increase the water content.

• BMB Reports
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• v.35 no.6
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• pp.590-594
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• 2002

To elucidate the effect of gamma-irradiation on the molecular properties of myoglobin, the secondary and tertiary structures, as well as the molecular weight size of the protein, were examined after irradiation at various irradiation doses. Gamma-irradiation of myoglobin solutions caused the disruption of the ordered structure of the protein molecules, as well as degradation, cross-linking, and aggregation of the polypeptide chains. A SDS-PAGE study indicated that irradiation caused initial fragmentation of the proteins and subsequent aggregation, due to cross-linking of the protein molecules. The effect of irradiation on the protein was more significant at lower protein concentrations. Ascorbic acid protected against the degradation and aggregation of proteins by scavenging oxygen radicals that are produced by irradiation. A circular dichroism study showed that an increase of the irradiation decreased the a-helical content of myoglobin with a concurrent increase of the aperiodic structure content. Fluorescence spectroscopy indicated that irradiation increased the emission intensity that was excited at 280 nm.

• Food Science and Biotechnology
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• v.14 no.2
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• pp.259-262
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• 2005

A fraction (CMEx-AH-${\beta}$) of water-soluble polysaccharides, showing selective antitumor activities, was isolated from the mycelia of solid cultured Agaricus blazei Murill by hot-water extraction, ethanol precipitation, and series of chromatography. Chemical characteristics of CMEx-AH-${\beta}$, were as follows: carbohydrate content, 48%; monosaccharide composition, Man:Glu:Gal (2:93:5); molecular weight, $2{\times}10^5$; uronic acid content, 6.2%. Fundamental structure of CMEx-AH-${\beta}$, was deduced as ${\beta}-(1\;{\rightarrow}\;6)$-D-glucan with ${\beta}-(1\;{\rightarrow}\;3)$-D-glucosidic side chains based on results of methylation and $^{13}C$ NMR spectroscopic analyses.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.7
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• pp.3284-3306
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• 2018

This study proposes a method to develop an authoring system(GeoMaTree) for diverse trees that constitute a virtual landscape. The GeoMaTree system enables the simple, intuitive production of an efficient structure, and supports real-time processing. The core of the proposed system is a procedural modeling based on a mathematical model and an application that supports digital content creation on diverse platforms. The procedural modeling allows users to control the complex pattern of branch propagation through an intuitive process. The application is a multi-resolution 3D model that supports appropriate optimization for a tree structure. The application and a compatible function, with commercial tools for supporting the creation of realistic synthetic images and virtual landscapes, are implemented, and the proposed system is applied to a variety of 3D image content.

• Journal of Korea Foundry Society
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• v.25 no.2
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• pp.95-101
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• 2005

This study has been carried out to investigate the microstructure of austempered high carbon cast steel with the variation of silicon and heat treatment conditions. The results show that an lower ausferritic structure is formed at the low austemepring temperature ($250{\sim}300^{\circ}C$) and an upper ausferritic structure is formed at the high austemepring temperature ($350{\sim}400^{\circ}C$). As an austempering temperature increased, the retained austenite volume fraction increased, however hardness decreased. Also, as a silicon content increased, the precipitation of cementite was suppressed, therefore 2nd reaction of autempering transformation was delayed.

• Food Science and Biotechnology
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• v.14 no.6
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• pp.783-787
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• 2005

Fraction (PMEx-AH-${\beta}$) of water-soluble polysaccharide, showing stimulating activity against macrophages, was isolated from mycelia of solid cultured Phellinus linteus by hot-water extraction, ethanol precipitation, and chromatography. Chemical characteristics of PMEx-AH-${\beta}$ were as follows: carbohydrate content, 71%; monosaccharide composition, Man:Glu:Gal (9:64:27); molecular weight, $1-7{\times}10^4$; uronic acid content, 6.8%. Fundamental structure of PMEx-AH-${\beta}$ is deduced as ${\beta}$-($1{$\rightarrow}6$)-D-glucan with ${\beta}$-($1{\rightarow}3$)-D-glucosidic side chains based on methylation analysis.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.11
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• pp.556-560
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• 2004

In this paper, thermal and structural properties of epoxy/elastomer blend were measured by DSC, TGA and FESEM. Specimens were made of dumbbell forms by the ratio of 5, 10, 15, and 20[phr] by changing elastomer content. The measuring temperature ranges of DSC were from -20[℃] to 150[℃] and heating rate was 4[℃/min]. And the measuring temperature ranges of TGA were from 0[℃] to 800[℃], and heating rate was 5[℃/min]. Also we observed structure of specimens through FESEM with magnification of 1000 times and voltage of 15[kV] by breaking quenched specimens. As experimental results, we could know that thermal and structural properties were improved according to decrease of elastomer content. Because it increased glass transition temperature, high temperature and structure of elastic epoxy.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.2
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• pp.147-152
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• 2002

Carbon nitride thin films were deposited by reactive sputtering for the hard coating materials on Si wafer and tool steels. When the nitrogen content of carbon nitride film on tool steel is 33.4%, the mean hardness and elastic modulus are 49.34 GPa and 307.2 GPa respectively. The nitrided or carburised surface acts as the diffusion barrier which shows better adhesion of carbon nitride thin film on the steel surface. To prevent nitrogen diffusion from the film, steel substrate can be saturated by nitrogen forming a Fe$_3$N layer. The desirable structure at the surface after carburising is martensite, but sometimes, due to high carbon content an proeutectoid Fe$_3$C structure may form at the grain boundaries, leaving the overall surface brittle and may cause defects.

• Structural Engineering and Mechanics
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• v.3 no.5
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• pp.497-509
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• 1995

Effectiveness of multiple tuned mass dampers (MTMD) in suppressing the dynamic response of base excited structure for first mode vibration is investigated. The effectiveness of the MTMD is expressed by the ratio of the root mean square (RMS) displacement of the structure with MTMD to corresponding displacement without MTMD. The frequency content of base excitation is modelled as a broad-band stationary random process. The MTMD's with uniformly distributed natural frequencies are considered for this purpose. A parametric study is conducted to investigate the fundamental characteristics of the MTMD's and the effect of important parameters on the effectiveness of the MTMD's. The parameters include: the fundamental characteristics of the MTMD system such as damping, mass ratio, total number of MTMD, tuning frequency ratio, frequency spacing of the dampers and frequency content of the base excitation. It has been shown that MTMD can be more effective and more robust than a single TMD with equal mass and damping ratio.