• 대한수학회논문집
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• 제35권2호
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• pp.401-415
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• 2020

It is well-known that if char𝕜 = 0, then an Artinian monomial complete intersection quotient 𝕜[x₁, …, x_n]/(x₁^a₁, …, x_n^a_n) has the strong Lefschetz property in the narrow sense, and it is decomposed by the direct sum of irreducible 𝖘𝖑₂-modules. For an Artinian ring A = 𝕜[x₁, x₂, x₃]/(x₁⁶, x₂⁶, x₃⁶), by the Schur-Weyl duality theorem, there exist 56 trivial representations, 70 standard representations, and 20 sign representations inside A. In this paper we find an explicit basis for A, which is compatible with the S₃-module structure.

• 대한수학회보
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• 제43권3호
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• pp.519-529
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• 2006

The Property P Conjecture States that the 3-manifold $Y_r$ obtained by Dehn surgery on a non-trivial knot in $S^3$ with surgery coefficient ${\gamma}{\in}Q$ has the non-trivial fundamental group (so not simply connected). Recently Kronheimer and Mrowka provided a proof of the Property P conjecture for the case ${\gamma}={\pm}2$ that was the only remaining case to be established for the conjecture. In particular, their results show that the two phenomena of having a cyclic fundamental group and having a homomorphism with non-cyclic image in SU(2) are quite different for 3-manifolds obtained by Dehn filings. In this paper we extend their results to some other Dehn surgeries via the A-polynomial, and provide more evidence of the ubiquity of the above mentioned phenomena.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2004년도 학술대회지
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• pp.59-63
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• 2004

In recent days. it is necessary to find environment-friendly way of diposing industrial waste and reclying system. So this study will analyze the property of Porous concrete improved by concrete waste powder and recycled lightweight aggregate and then suggest the ways of reclying. The method deals with experimenting unit weight of capacity. thermal conductivity, compression and ultrasonic pluse velocity. Considering the relation between ultrasonic pluse velocity and unit weight & thermal conductivity through the graph. the result of relation between ultrasonic pluse velocity and unit weight & thermal conductivity on the graph expessed their high interaction shown as direct proportion on the graph. Recycled Porous concrete merits lightweight and adiabatic. Therefore. we will expect that the current using ALC and Recycled Porous concrete has be similar thermal conductivity.

• 대한수학회지
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• 제49권2호
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• pp.405-417
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• 2012

We find the Hilbert function and the minimal free resolution of a star-configuration in $\mathbb{P}^n$. The conditions are provided under which the Hilbert function of a star-configuration in $\mathbb{P}^2$ is generic or non-generic We also prove that if $\mathbb{X}$ and $\mathbb{Y}$ are linear star-configurations in $\mathbb{P}^2$ of types t and s, respectively, with $s{\geq}t{\geq}3$, then the Artinian k-algebra $R/(I_{\mathbb{X}}+I_{\mathbb{Y})$ has the weak Lefschetz property.

• 대한수학회지
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• 제57권2호
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• pp.283-312
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• 2020

A sufficient condition for an Artinian complete intersection quotient S = 𝕜[x, y]/(x^m, yⁿ), where 𝕜 is an algebraically closed field of a prime characteristic, to have the strong Lefschetz property (SLP) was proved by S. B. Glasby, C. E. Praezer, and B. Xia in [3]. In contrast, we find a necessary and sufficient condition on m, n satisfying 3 ≤ m ≤ n and p > 2m-3 for S to fail to have the SLP. Moreover we find the Jordan types for S failing to have SLP for m ≤ n and m = 3, 4.

• Journal of Electrochemical Science and Technology
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• 제1권2호
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• pp.112-116
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• 2010

Fractal property of the passivated steel surface was investigated on the basis of scaling analysis with a special focus on its relationship with corrosion resistance. For this purpose, the surface of stainless steel was intentionally oxidized under a variety of passivation conditions and its scaling property was analyzed by a triangulation method. The morphology of the passivated steel surface was satisfactorily evaluated with fractal dimension. From the chronoamperometry and impedance measurement, it proved that lower fractal dimension leads to more enhanced corrosion resistance. The higher passivity of the steel surface with lower fractal dimension was discussed in terms of active area and structural imperfection.

• 충청수학회지
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• 제30권4호
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• pp.435-443
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• 2017

We find a graded minimal free resolution of the union of two star configurations ${\mathbb{X}}$ and ${\mathbb{Y}}$ (not necessarily linear star configurations) in ${\mathbb{P}}^n$ of type s and t for s, $t{\geq}2$, and $n{\geq}3$. As an application, we prove that an Artinian ring $R/(I_{\mathbb{X}}+I_{\mathbb{Y}})$ of two linear star configurations ${\mathbb{X}}$ and ${\mathbb{Y}}$ in ${\mathbb{P}}^3$ of type s and t has the weak Lefschetz property for $s{\geq}{\lfloor}\frac{1}{2}(^t_2){\rfloor}$ and $t{\geq}2$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 방전 플라즈마 유기절연재료 초전도 자성체연구회
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• pp.34-37
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• 2004

It is well known that Ag-CdO alloy for electrical contactor has been widely used in weak or middle electric current field. But it is necessary to decrease Cd contents without decrease of contactor property because Cd is harmful to human body. The present work has been carried out to investigate effects of Mm (misch metal) addition on the property of Ag-CdO alloy for electrical contactor. As the results of present works, hardness and strength was improved and arc resistance was improved, also, in spite of decrease Cd contents by the Mm addition. It was estimated that Ag-oxide particle was refined by Mm addition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.84-87
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• 1996

This paper presents a energy function to reflect the control effect of speed governor which has a cut-off property which means position and rate limit The proposed energy function satisfies the semi-negativeness of its time derivative and well reflects the parameters of speed governor to the energy function. The transient stability analysis by the direct method for the single machine infinite bus system has been conducted with the use of the proposed energy function, which shows that the results by the direct method well agree with that by the conventional time simulation method. This thesis shows a possibility of more accurate stability analysis by taking into account the cut-off property of speed governor's output.

• 한국초전도ㆍ저온공학회논문지
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• 제12권4호
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• pp.20-23
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• 2010

In this study, the electromechanical property of REBCO coated conductor (CC) tape adopting a stainless steel substrate has been investigated. Sample was subjected to uniaxial tension and measured its mechanical properties at RT and 77 K. $I_c-{\varepsilon}_t$ relations was also studied in which the strain and stress corresponding to the 95% $I_c$ retention and reversible strain limit were measured. In addition, these results were compared to the case of conventional REBCO CC tape adopting a Hastelloy substrate. As a result, by adopting a stainless steel substrate comparable strength and good electromechanical property to Hastelloy one could be achieved.