• Journal of the KSME
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• v.35 no.3
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• pp.242-251
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• 1995

균열(crack)을 갖는 부재의 강도를 평가할 때에 있어서 응력확대계수를 이용하는 데에 대한 합 리성은 현재까지 의심할 여지없는 사실로서 받아들여지고 있다. 그 근거는 소규모 항복의 조건이 만족되고 있을 때에는 균열의 치수가 틀리더라도 균열선단부근의 역학적 상태는 응력확대계수 만에 의해 지배된다는 사실에 있다. 한편, 노치(notch)를 갖는 부재의 강도를 평가할 때에 최대 응력만을 고려하는 것은 불충분하다. 예를 들면, 그것은 노치반경 .rho.가 10 mm 정도의 노치와 .rho.가 0에 상당하는 균열과는 최대응력 .sigma.$_{max}$를 같게 하더라도 역학적 상태의 가 혹함(severity)이 동일하게 되지 않는다는 사실로부터도 명백하다. 그렇다면, .rho.가 0과 10 mm의 중간값, 예를 들면 1 mm 혹은 0.1 mm일 때와 같은 역학적 상태의 가혹함이 생기기 위해서는 .sigma.$_{max}$가 얼마이면 될까\ulcorner 또는, 만약 .rho.가 틀릴 때, 동일한 현상(same phenomenon)이 생기지 않는다고 한다면 그것은 어떠한 물리적 배경에 근거한 것일까\ulcorner 이글에 서는 이러한 질문에 대한 해답과 함께 선형파괴역학과 선형노치역학이 생겨나게 된 간략한 역사적 배경과 선형노치역학의 개념에 대해 언급하기로 한다.

• Journal of the Korean Chemical Society
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• v.7 no.1
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• pp.69-73
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• 1963

The basicities of 16 substituted azoxybenzenes have been measured by U.V. spectrophotometric method. The effects of substituents on the basicities are discussed in terms of Hammett's equation. The reaction constants, ${\rho}^X_Y$ and ${\rho}^Y_X$ , in a modified equation, log $K_{XY}/K_{\infty}={\sigma}_X{\rho}^Y_X+{\sigma}_Y{\rho}^X_Y$, are $2.46{\pm}0.12$ and $2.25{\pm}0.26$ respectively. The validity of the equation is analysed by a statistical method, and the structure of the conjugate acid of the substituted azoxybenzenes is proposed.

• Bulletin of the Korean Chemical Society
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• v.23 no.5
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• pp.715-720
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• 2002

Kinetic studies of the reaction of Z-aryl cyclobutanecarboxylates with X-pyridines in acetonitrile at $55.0^{\circ}C$ have been carried out. The reaction proceeds by a stepwise mechanism in which the rate-determining step is the breakdown of the zwitterion ic tetrahedral intermediate, T $\pm$ . These mechanistic conclusions are drawn based on (i) the large magnitude of ${\rho}X$ and $\rhoZ$, (ⅱ) the positive sign of ${\rho}XZ$ and the larger magnitude of $\rhoXZ$ than normal SN2 processes, (ⅲ) a small positive enthalpy of activation, ${\Delta}H{\neq}$, and a large negative, ${\Delta}S{\neq}$, and lastly (iv) adherence to the reactivity-selectivity principle (RSP) in all cases.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.285-288
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• 2011

시맨틱 웹상에서 메타 데이터를 표현하는 RDF 데이터에 대한 질의 처리를 위해 여러 가지 RDF 질의어가 제안되었으나 리소스간의 복잡한 관계성들의 발견(discovery)을 위한 충분한 지원을 하지 못하고 있다. 본 논문에서는 시맨틱 연관성 검색 유형의 하나인 ${\rho}$-intersect 연산의 처리 방법을 소개한다. 이를 위해 접미사 배열을 이용한 인덱싱과 ${\rho}$-intersect 연산의 특징을 고려한 최적화 방법을 활용한다. 제안된 처리 기법을 통해 전형적인 RDF 질의 유형뿐만 아니라 시맨틱 연관성 질의 유형도 지원할 수 있도록 한다.

• Journal for History of Mathematics
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• v.24 no.2
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• pp.31-46
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• 2011

[ ${\ll}$ ]n divisions of figures(${\pi}{\varepsilon}{\rho}{\acute{\iota}}\;{\delta}{\iota}{\alpha}{\iota}{\rho}{\acute{\varepsilon}}{\sigma}{\varepsilon}{\omega}{\nu}\;{\beta}{\iota}{\beta}{\lambda}{\acute{\iota}}o{\nu}$)${\gg}$ is one of the works written by Euclid, but little known to us. In this paper, we introduce this Euclid's book on divisions of figures with its brief history, analyse its contents, and discuss how to use it in mathematics education.

• Journal of the Korean Ceramic Society
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• v.40 no.7
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• pp.632-636
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• 2003

To prepare the alumina cement free vibrated alumina castable, $\rho$-alumina is employed as a binder material, and nano-sized clay is added to enhance the curing strength and give thixotropic behavior. The rheological behavior of matrix of castable is controlled by investigating the influences of ultrafines, $\rho$-alumina, and nano-sized clay on the viscosity of matrix. The microsilica and ultrafine alumina were added 3 wt% and 4 wt%, respectively to the matrix, which showed that the viscosities tends to be lowest values. The rheological property of the matrix is well established by adding $\rho$-alumina as 8 wt% and clay as 4 wt%. The thixotropic behavior of the $\rho$-alumina bonded castable was appeared by introducing nano-sized clay into the matrix and adjusting the pH near to the PZC of the clay suspension.

• Journal of the Korean Mathematical Society
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• v.57 no.4
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• pp.1031-1052
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• 2020

In this paper our aim is to find various radii problems of the generalized Mittag-Leffler function for three different kinds of normalization by using their Hadamard factorization in such a way that the resulting functions are analytic. The basic tool of this study is the Mittag-Leffler function in series. Also we have shown that the obtained radii are the smallest positive roots of some functional equations.

• Communications of the Korean Mathematical Society
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• v.15 no.4
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• pp.617-626
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• 2000

We study the vectors related tro states on the Cuntz algebra Ο(sub)n and prove hat, for tow states $\omega$ and $\rho$ on Ο(sub)n with $\omega$│UHF(sub)n = $\rho$│UHF(sub)n, if ($\omega$(s$_1$), …, $\omega$(s(sub)n)) and ($\rho$(s$_1$),…, $\rho$(s(sub)n)) are unit vectors, then they and linearly dependent. We also study the linear functional on Ο(sub)n associated to a sequence of unit vectors in C(sup)n which is the generalization of the Cuntz state. We show that if the linear functional associated to a sequence of unit vectors with a certain condition is a state, then it is just the Cuntz state.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.69-74
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• 2016

The present study was undertaken to investigate the influence of cardamonin on vascular smooth muscle contractility and to determine the mechanism(s) involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Cardamonin significantly relaxed fluoride-, phenylephrine-, and phorbol ester-induced vascular contractions, suggesting that it has an anti-hypertensive effect on agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, cardamonin significantly inhibited the fluoride-induced increase in pMYPT1 level and phenylephrine-induced increase in pERK1/2 level, suggesting inhibition of Rho-kinase and MEK activity and subsequent phosphorylation of MYPT1 and ERK1/2. This study provides evidence that the relaxing effect of cardamonin on agonist-induced vascular contraction regardless of endothelial function involves inhibition of Rho-kinase and MEK activity.

• The Pure and Applied Mathematics
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• v.27 no.1
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• pp.25-33
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• 2020

In this paper, we consider the following quadratic (ρ₁, ρ₂)-functional equation (0, 1) $$N(2f({\frac{x+y}{2}})+2f({\frac{x-y}{2}})-f(x)-f(y)-{\rho}_1(f(x+y)+f(x-y)-2f(x)-2f(y))-{\rho}_2(4f({\frac{x+y}{2}})+f(x-y)-f(x)-f(y)),t){\geq}{\frac{t}{t+{\varphi}(x,y)}}$$, where ρ₂ are fixed nonzero real numbers with ρ₂ ≠ 1 and 2ρ₁ + 2ρ₂≠ 1, in fuzzy normed spaces. Using the fixed point method, we prove the Hyers-Ulam stability of the quadratic (ρ₁, ρ₂)-functional equation (0.1) in fuzzy Banach spaces.