• Structural Engineering and Mechanics
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• 제34권1호
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• pp.85-95
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• 2010

In this paper, numerical solution of the singular integral equation for the multiple curved branch-cracks is investigated. If some quadrature rule is used, one difficult point in the problem is to balance the number of unknowns and equations in the solution. This difficult point was overcome by taking the following steps: (a) to place a point dislocation at the intersecting point of branches, (b) to use the curve length method to covert the integral on the curve to an integral on the real axis, (c) to use the semi-open quadrature rule in the integration. After taking these steps, the number of the unknowns is equal to the number of the resulting algebraic equations. This is a particular advantage of the suggested method. In addition, accurate results for the stress intensity factors (SIFs) at crack tips have been found in a numerical example. Finally, several numerical examples are given to illustrate the efficiency of the method presented.

• 호남수학학술지
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• 제43권4호
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• pp.597-612
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• 2021

Several useful and interesting extensions of the various special functions have been introduced by many authors during the last few decades. Various integral formulas associated with Wright function have been studied and a noteworthy amount of work have found in literature. The principal object of the present paper is to evaluate finite integral formulas containing the product of orthogonal polynomials with generalized Wright function. These integral formulas are expressed in terms of Srivastava and Daoust function. Some interesting particular cases are obtained from the main results by specialising the suitable values of the parameters involved.

• 한국학교수학회논문집
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• 제11권3호
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• pp.421-438
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• 2008

구분구적법에 대한 이해는 리만합의 극한으로 정의되는 정적분에 대한 이해의 기초가 된다. 그러나 선행연구는 구분구적법과 리만합의 극한으로서 정적분 개념에 대한 학생들의 이해에 여러 가지 한계가 있음을 지적하였다. 이 연구에서는 선행연구 분석을 통해 구분구적법의 개념 지도에 있어 크게 두 가지 어려움이 있음을 확인하였으며, 이를 개선하는데 기여할 만한 교수학적 시사점을 각각 기술하였다. 나아가 미국, 영국, 일본 교과서에 비추어 우리나라 교과서에서만 고유하게 다루어지는 정적분과 무한급수의 관계가 리만합의 극한이라는 정적분의 개념 지도에 있어 필수적인 내용 요소인지를 반성적으로 검토하였다.

• 대한수학회보
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• 제48권6호
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• pp.1207-1218
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• 2011

Let * be a star-operation on an integral domain R, and let $\mathfrak{I}_*^+(R)$ be the semigroup of *-invertible integral *-ideals of R. In this article, we introduce the concept of a *-coatom, and we then characterize when $\mathfrak{I}_*^+(R)$ is a free semigroup with a set of free generators consisting of *-coatoms. In particular, we show that $\mathfrak{I}_*^+(R)$ is a free semigroup if and only if R is a Krull domain and each ${\upsilon}$-invertible ${\upsilon}$-ideal is *-invertible. As a corollary, we obtain some characterizations of *-Dedekind domains.

• 대한수학회보
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• 제58권1호
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• pp.71-111
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• 2021

We consider the boundary value problem for the deflection of a finite beam on an elastic foundation subject to vertical loading. We construct a one-to-one correspondence �� from the set of equivalent well-posed two-point boundary conditions to gl(4, ℂ). Using ��, we derive eigenconditions for the integral operator ��M for each well-posed two-point boundary condition represented by M ∈ gl(4, 8, ℂ). Special features of our eigenconditions include; (1) they isolate the effect of the boundary condition M on Spec ��M, (2) they connect Spec ��M to Spec ����,α,k whose structure has been well understood. Using our eigenconditions, we show that, for each nonzero real λ ∉ Spec ����,α,k, there exists a real well-posed boundary condition M such that λ ∈ Spec ��M. This in particular shows that the integral operators ��M, arising from well-posed boundary conditions, may not be positive nor contractive in general, as opposed to ����,α,k.

• 한국인터넷방송통신학회논문지
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• 제9권1호
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• pp.31-37
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• 2009

본 논문은 컬러영상의 특정 클러스터에 해당하는 낙관을 추출하기 위하여 확장된 퍼지적분을 제안하였다. 기존의 퍼지적분은 평가항목에 대한 부정적인 측면을 강조하였다. 제안된 방법은 무게중심법을 통하여 인접정보를 이용하여 평가항목간의 보상적인 측면을 고려하였다. 평가 항목간의 min 연산자로서의 기존의 퍼지적분의 특징에만 기초하는 방법은 낙관 영상의 끊어지는 부분 처리와 전체적인 영상의 유연성을 확보하는 데는 다소 부족한 느낌이 들었다. 그래서 이를 해결하기 위해 무게중심을 이용하여 전체적인 영상의 유연성을 확보 하였다. 그 결과 실 생활의 영수증의 낙관을 분리하는 실질적인 문제에 관한 자료들에 대하여 실험을 수행하였다.

• Korean Journal of Mathematics
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• 제30권4호
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• pp.593-601
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• 2022

Let C(Q) denote Yeh-Wiener space, the space of all real-valued continuous functions x(s, t) on Q ≡ [0, S] × [0, T] with x(s, 0) = x(0, t) = 0 for every (s, t) ∈ Q. For each partition τ = τ_m,n = {(s_i, t_j)|i = 1, . . . , m, j = 1, . . . , n} of Q with 0 = s₀ < s₁ < . . . < s_m = S and 0 = t₀ < t₁ < . . . < t_n = T, define a random vector X_τ : C(Q) → ℝ^mn by X_τ (x) = (x(s₁, t₁), . . . , x(s_m, t_n)). In this paper we study the conditional integral transform and the conditional convolution product for a class of cylinder type functionals defined on K(Q) with a given conditioning function X_τ above, where K(Q)is the space of all complex valued continuous functions of two variables on Q which satify x(s, 0) = x(0, t) = 0 for every (s, t) ∈ Q. In particular we derive a useful equation which allows to calculate the conditional integral transform of the conditional convolution product without ever actually calculating convolution product or conditional convolution product.

• Wind and Structures
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• 제2권4호
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• pp.253-266
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• 1999

This paper presents the effects of free-stream turbulence on streamwise surface pressure fluctuations on two-dimensional rectangular cylinders. Particular attention is given to possible effects of turbulence integral scale on fluctuation and peak pressures. The mean, standard deviation, peak pressure coefficients, spectra and cross-correlation of fluctuating pressures were measured to investigate the nature of the separation and reattachment phenomenon in turbulent flows over a wide range of turbulence intensity and integral scale.

• 대한수학회지
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• 제38권1호
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• pp.61-76
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• 2001

In this paper we define the concept of a conditional Fourier-Feynman transform and a conditional convolution product and obtain several interesting relationships between them. In particular we show that the conditional transform of the conditional convolution product is the product of conditional transforms, and that the conditional convolution product of conditional transforms is the conditional transform of the product of the functionals.

• Kyungpook Mathematical Journal
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• 제50권1호
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• pp.131-152
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• 2010

In this paper, by introducing some parameters we establish an extension of Hardy-Hilbert's integral inequality and the corresponding inequality for series. As an application, the reverses, some particular results and their equivalent forms are considered.