• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.431-431
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• 2012

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.431-431
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• 2004

• Journal of the Korean institute of surface engineering
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• v.44 no.4
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• pp.149-154
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• 2011

Martensitic stainless steel STS 431 has been nitrided by active screen ion nitriding under the various temperature and time. The thickness of diffusion layer, case depth, hardness and composition phases were investigated using field emission scanning electron microscopy (FE-SEM), micro-Vickers hardness tester, X-ray diffraction (XRD) and glow discharge spectroscopy (GDS). It was observed that the thickness of diffusion layer depends strongly on the treatment temperature and time. A sample, which was nitrided at $450^{\circ}C$ for 8hours, was a maximum hardness of Hv0.01 1558 and nitride layer of $70{\mu}m$. As shown in XRD patterns, $\varepsilon(Fe_{2-3}N)$ and expanded martensite (${\alpha}_N$) phases which was saturated with nitrogen solid solution were in the nitrided layer treated at $450^{\circ}C$ for 2 hours. Composition phases of $\varepsilon$ $(Fe_{2-3}N)$ and ${\gamma}'$ ($Fe_4N$) were observed after active screen nitriding at $450^{\circ}C$ for 8 hours.

• Journal of the Chungcheong Mathematical Society
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• v.28 no.3
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• pp.431-441
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• 2015

Topology may described a pattern of existence of elements of a given set X. The family ${\tau}(X)$ of all topologies given on a set X form a complete lattice. We will give some topologies on this lattice ${\tau}(X)$ using a topology on X and regard ${\tau}(X)$ a topological space. Our purpose of this study is to give new topologies on the family ${\tau}(X)$ of all topologies induced by old one and its ${\theta}$ topology and to compare them.

• The Korean Journal of Nuclear Medicine
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• v.34 no.2
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• pp.144-153
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• 2000

Purpose: The purpose of this study was to evaluate the relationship between radiation-induced activation of DNA repair genes and radiation induced apoptosis in A431 cell line. Materials and Methods: Five and 25 Gys of gamma radiation were given to A431 cells by a Cs-137 cell irradiator. Apoptosis was evaluated by flow cytometry using annexin V-fluorescein isothiocyanate and propidium iodide staining. The expression of DNA repair genes was evaluated by both Northern and Western blot analyses. Results: The number of apoptotic cells increased with the increased radiation dose. It increased most significantly at 12 hours after irradiation. Expression of p53, p21, and hRAD50 reached the highest level at 12 hours after 5 Gy irradiation. In response to 25 Gy irradiation, hRAD50 and p21 were expressed maximally at 12 hours, but p53 and GADD45 genes showed the highest expression level after 12 hours. Conclusion: Induction of apoptosis and DNA repair by ionizing radiation were closely correlated. The peak time of inducing apoptosis and DNA repair was 12 hours in this study model. hRAD50, a recently discovered DNA repair gene, was also associated with radiation-induced apoptosis.

• Bulletin of the Korean Mathematical Society
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• v.39 no.3
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• pp.431-440
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• 2002

Recently P. Ozsv$\'{a}$th Z. Szab$\'{o}$ proved higher type adjunction inequalities for embedded surfaces in 4-manifolds of non-simple type. The aim of this short paper is to give a simple and direct proof of such higher type adjunction inequalities for smoothly embedded surfaces with negative self-intersection number in smooth 4-manifolds of non-simple type. This will be achieved through a relation between the Seiberg-Witten invariants used to get adjunction inequalities of 4-manifolds of simple type and a blow-up formula.

• The Journal of Internal Korean Medicine
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• v.18 no.1
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• pp.231-241
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• 1997

The purpose of this research was to investigate effect of water extract of Euphorbiae Pekinensis Radix and Moutan Cortex Radicis on the proliferation of human cancer cell-lines. The effects of Euphorbiae Pekinensis Radix and Moutan Cortex Radicis on the proliferation of A431, HeLa, MOLT-4, K562 cells, Balb/c 3T3 cells, mouse thymocytes, splenocytes and human lymphocytes were estimated by MTT colorimetric assay. The results were as follows; 1. In proliferation of A431, HeLa, MOLT-4 and K562 cell-lines, Euphorbiae Pekinensis Radix and Moutan Cortex Radicis inhibited the proliferation of K562 cells. 2. In the combined effect of Euphorbiae Pekinensis Radix and mitomycin C, Moutan Cortex Radicis and mitomycin C, all herbs stimulated the proliferation of MOL T-4 cells. 3. Euphorbiae Pekinensis Radix and Moutan Cortex Radicis did not inhibited the proliferation of Balb/c 3T3 cells. 4. Euphorbiae Pekinensis Radix and Moutan Cortex Radicis stimulated the proliferation of mouse thymocytes. 5. Euphorbiae Pekinensis Radix and Moutan Cortex Radicis stimulated the proliferation of mouse splenocytes. 6. Euphorbiae Pekinensis Radix and Moutan Cortex Radicis stimulated the proliferation of human lymphocytes.

• Herbal Formula Science
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• v.5 no.1
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• pp.169-178
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• 1997

To investigate effect of water extract of Asparagi Tuber(天門冬) on human cancer cell-lines and immunocytes, this research estimated proliferation of A431 cell line, KHOS-NP cell line, mouse thymocytes and mouse splenocytes, Nitric Oxide(NO) from macrophage, apoptosis and subpopulation of the mouse thymocytes. The result were obtained as follows ; 1. Asparagi Tuber inhibited the proliferation of A431 cell line. 2. Asparagi Tuber inhibited the proliferation of KHOS-NP cell line. 3. Asparagi Tuber accelerated the proliferation of mouse thymocytes. 4. Asparagi Tuber inhibited the proliferation of mouse splenocytes. 5. Asparagi Tuber $100{\mu}g/m{\ell}$ inhibited the production of NO from macrophages in vitro, being compared NPS+IFN treated group. 6. Asparagi Tuber inhibited the production of NO from macrophages in vivo, being compared LPS+IFN treated group. 7. Asparagi Tuber accelerated the induction of apoptosis of the mouse thymocytes. 8. In subpopulation Asparagi Tuber increased $T_H$ of the mouse thymocytes, but decreased $T_C/T_S$ of the mouse thymocytes.

• Honam Mathematical Journal
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• v.37 no.4
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• pp.431-440
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• 2015

Let G be a semialgebraic group which is not necessarily compact. Let X be a semialgebraically proper G-set such that the orbit space has a semialgebraic structure. In this paper we prove the existence of semialgebraic slices of X. Moreover X can be covered by finitely many semialgebraic G-tubes.

• Structural Engineering and Mechanics
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• v.23 no.4
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• pp.431-447
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• 2006

A new incremental finite element model is developed to simulate the frictional contact of elastic bodies. The incremental convex programming method is exploited, in the framework of finite element approach, to recast the variational inequality principle of contact problem in a discretized form. The non-classical friction model of Oden and Pires is adopted, however, the friction effect is represented by an equivalent non-linear stiffness rather than additional constraints. Different parametric studies are worked out to address the versatility of the proposed model.