• Transactions on Electrical and Electronic Materials
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• v.15 no.6
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• pp.305-308
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• 2014

Organosilyl-modified and star-shaped poly (${\varepsilon}$-caprolactone) (m-PCL) was prepared, and added to polymethylsilsesquioxane (PMSSQ), to make composites. The end groups of m-PCL are chemically similar to PMSSQ, and m-PCL mixed well with PMSSQ in the composite. Porous PMSSQ film was made by further calcination of the composite film at elevated temperature. m-PCL-templated PMSSQ and the as-prepared porous PMSSQ were structurally, optically, and thermally characterized in thin films. The chemical binding of m-PCL and PMSSQ effectively suppressed the phase separation of PMSSQ and m-PCL during the curing process. After calcination at elevated temperature, there remained many pores in the PMSSQ matrix. The refractive indices of the resulting porous PMSSQ thin films decreased with increase of the film porosities, depending on the initial m-PCL loadings.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1505_1506
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• 2009

In this paper, micro cantilevers which are made of two different materials - fused quartz and single crystalline silicon - and have similar dimensions were fabricated and their mechanical Q-factors were evaluated to compare intrinsic damping properties of those two materials. Resonant frequencies and Q-factors were measured for the cantilevers having fixed widths and thicknesses, and different lengths. The measured Q-values are in a range of 64,000 - 108,000 for fused quartz cantilevers, and 31,000 - 35,000 for silicon cantilevers, respectively. Experimental results support high Q-factors of fused quartz compared to single crystalline silicon due to its good intrinsic damping properties.

• Korean Institute of Interior Design Journal
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• v.13 no.1
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• pp.20-29
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• 2004

In the present architectural culture of Korea, the expression of Korean values and the contemporary trends of global architectures are not identified and arranged distinctly, so diverse tendencies are applied to the architectures of Korea recklessly. In this situation, minimal architecture is significant, which pursues the essence of architecture through the minimal materials. This thesis analyzes the characteristics of minimal architecture seeking after the essence of architecture by minimalization and examines Seung, Hyosang's architectures showing expressional traits similar to those of minimal architecture in the modem architectures of Korea, so this study can show the expressional characteristics and materials of minimal architecture. Nevertheless, it does not mean that all the Seung, Hyosang's works have the tendency of minimal architecture and that he has to be classified as a minimal architect, but it means only that the values and thoughts like the expressional traits of minimal architecture are seen in his architectural opinions! and works, which will be the subject of this study.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1766-1771
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• 2007

This paper presents plastic limit loads and approximate J-integral estimates for circumferential part-through surface crack at the interface between elbows and pipes. Based on finite element limit analyses using elastic-perfectly plastic materials, plastic limit moments under in-plane bending are obtained and it is found that they are similar those for circumferential part-through surface cracks in the center of elbow. Based on present FE results, closed-form limit load solutions are proposed. Welds are not explicitly considered and all materials are assumed to be homogeneous. And the method to estimate the elastic-plastic J-integral for circumferential part-through surface cracks at the interface between elbows and straight pipes is proposed based on the reference stress approach, which was compared with corresponding solutions for straight pipes.

• Journal of Microbiology and Biotechnology
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• v.19 no.5
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• pp.530-536
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• 2009

Cobalt chloride ($CoCl_2$) treatment of cells in vitro has been shown to induce cellular changes that are similar to those seen following hypoxia. To identify genes that are differentially expressed in response to treatment with $CoCl_2$, we compared the mRNA expression profiles of PC-3 cells that were treated with $CoCl_2$ with those of untreated PC-3 cells, using specific arbitrary primers and two anchored oligo(dT) primers provided in the ACP-based GeneFishing kits. The results of this study demonstrated that the puromycin-sensitive aminopeptidase (PSA) gene was down regulated in PC-3 cells that were treated with $CoCl_2$. This downregulation of PSA expression, in turn, suppressed the proliferation, migration, and invasion of PC-3 cells, as well as the secretion and expression of matrix metalloproteinase-9 (MMP-9).

• Journal of the Korean Society for Heat Treatment
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• v.30 no.2
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• pp.67-73
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• 2017

Transformation behavior and hardness change were studied in five kinds of self-control steels; standard, high V, modified Ni, W, and high C-Ni steels. In the cooling rates of $10-100^{\circ}C/min$, the primary ferrite and bainite were formed, and the amount of the former increased with decreasing cooling rate. The bainite transformation temperature, Bs, was measured as 570, 560, 590, 575, and $565^{\circ}C$ in experimental steels, respectively, which was similar to the calculated temperature. The self-control, that is, the consistency in hardness, was observed, in which the hardness increased with the decrease in Bs. In the case of hot compression testing, the lower temperature deformation led to the enhancement in hardness.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.726-728
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• 2001

For the development of a small-sized superconducting magnetic energy storage (SMES) system we designed, fabricated and tested the model coil consisting five coils with different features, e.g. winding tensions, bore diameters and materials, cooling channels. The results show that even in the highly pre-stressed small coil A, about 70 % of the coils critical current are degraded. The quench current of the coils A, B and E with narrow cooling channels is two times as high as that of the coil C without them though they are similar except spacers. The test results also indicate that the usual training effect depends on the winding tensions of the coils but the quench characteristic does not change according to materials of a bobbin.

• Proceedings of the Safety Management and Science Conference
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• 2009.04a
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• pp.1-6
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• 2009

The fire of Sungnyemun, National Treasure of No.1, gave to the Korean people and fire investigators big pains. The aim of this study are the identification of combustion traces and fire patterns of wooden building fire, burned with an accelerator, after spraying flammable materials on the wooden floor through the field study observation. Also, in the case of the similar fire, these results will be as good references to fire investigators for accurate investigations.

• Journal of Plant Biology
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• v.8 no.1_2
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• pp.5-10
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• 1965

The effect of radioactive sulfur-35 on the growth and tissue respiration in rye, Secale cereale L., seedlings were studied in this investigation. The growth and respiration rate of the materials treated with the different intensities of radioactivity, represented by the different concentration(${\mu}c$) of radioactive sulfur were shown similar effects in treated groups as those of Gamma-ray or X-ray irradiation on plant materials. However, in the groups of ($0.1{\mu}c$ and ($0.4{\mu}c$ S35-solution, the growth and respiration rate were stimulated somewhat more clearly than in case of control. And the higher concentration groups, $1.6{\mu}c$, $6.4{\mu}c$, and $25.6{\mu}c$ were depressed of the growth and tissue respiration rate. The present data could be explained on the basis that the higher concentration treatments with the radioactive isotope did produce injury to the plant metabolism generally, but the moderate treatment would stimulate to the plant growth and tissue respiration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.6
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• pp.321-325
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• 2012

Collagen is widely used for regenerative therapy and pharmaceutical applications as one of the most useful scaffolds. Collagen is the most abundant protein in vertebrates and the natural substrate of various types of animal cells. Bone and dentin are mineralized tissues and almost similar in chemical components. They consist of collagen (18%), non-collagenous proteins (2%), hydroxyapatite (70%) and body fluid (10%) in weight volume. Pepsin-digested, type I collagen (atelocollagen) and heat-denatured collagen (gelatin) are basic collagenous materials for medical use. Demineralized dentin matrix (DDM) and demineralized bone matrix (DBM) belong to acid-insoluble group, and vital tooth-derived DDM is a unique dentin material including cementum and growth factors. In this review, collagen-based materials will be introduced and discussed for bone regenerative surgery.