• 대한수학회논문집
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• 제28권3호
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• pp.527-534
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• 2013

We first aim at proving an interesting easily derivable summation formula. Then it is easily seen that this formula immediately yields a hypergeometric summation theorem recently added to the literature by Qureshi et al. Moreover we apply the main formulas to present some interesting summation formulas, whose special cases are also seen to yield the earlier known results.

• 대한수학회논문집
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• 제32권4호
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• pp.999-1008
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• 2017

By mainly using certain properties arising from the semisimple Lie group SO(2, 1), we aim to show how a family of some interesting formulas for bilateral series and integrals involving Whittaker, Bessel functions, and their product can be obtained.

• 호남수학학술지
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• 제30권1호
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• pp.137-146
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• 2008

Many fractal objects observed in reality are characterized by some irregularities or complexities in their features. These properties can be measured and analyzed by means of fractal dimension. However, in many cases, the calculation of this value may not be so easy to utilize in applications. In this respect, we have treated a formal method to estimate the dimension of fractal curves.

• 호남수학학술지
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• 제38권4호
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• pp.685-692
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• 2016

The aim of this paper is to investigate the differentials of the hypercomplex valued functions in Clifford analysis. Like as the differentials defined by the naïve approach in one complex variable analysis, we define the differentials of functions with values in ternary number functions by same ways. And we survey the properties of each differential with respect to a non-commutativity of the skew field.

• East Asian mathematical journal
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• 제25권4호
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• pp.481-486
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• 2009

The first object of this note is to show that a summation formula due to Padmanabham for three-variables hypergeometric function $X_8$ introduced by Exton can be proved in a different (from Padmanabham's and his observation) yet, in a sense, conventional method, which has been employed in obtaining a variety of identities associated with hypergeometric series. The second purpose is to point out that one of two seemingly new hypergeometric identities due to Exton was already recorded and the other one is easily derivable from the first one. A corrected and a little more compact form of a general transform involving hypergeometric functions due to Exton is also given.

• Advances in Computational Design
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• 제9권1호
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• pp.39-52
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• 2024

If the governing differential equation arising from engineering problems is treated as an analytic, continuous and derivable function, it can be expanded by one point as a series of finite numbers. For the function to be zero for each value of its domain, the coefficients of each term of the same power must be zero. This results in a recursive relationship which, after applying the natural conditions or the boundary conditions, makes it possible to obtain the values of the derivatives of the function with acceptable accuracy. The elastoplastic analysis of an inhomogeneous thick sphere of metallic materials with linear variation of the modulus of elasticity, yield stress and Poisson's ratio as a function of radius subjected to internal pressure is presented. The Beltrami-Michell equation is established by combining equilibrium, compatibility and constitutive equations. Assuming axisymmetric conditions, the spherical coordinate parameters can be used as principal stress axes. Since there is no analytical solution, the natural boundary conditions are applied and the governing equations are solved using a proposed new method. The maximum effective stress of the von Mises yield criterion occurs at the inner surface; therefore, the negative sign of the linear yield stress gradation parameter should be considered to calculate the optimal yield pressure. The numerical examples are performed and the plots of the numerical results are presented. The validation of the numerical results is observed by modeling the elastoplastic heterogeneous thick sphere as a pressurized multilayer composite reservoir in Abaqus software. The subroutine USDFLD was additionally written to model the continuous gradation of the material.

• 정보와 통신
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• 제15권9호
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• pp.97-106
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• 1998

태양면의 교란으로 야기되는 지구근방 우주환경의 변화는 인류에게 막대한 사회경제적인 손실을 유발하므로 이를 예측하는 것은 매우 중요한 일이다. 본 연구에서 도입한 자기폭풍 예보코드는 이러한 변화양상을 지자기활동지수인 AE 및 Dst, 극관횡단전위차, 극지방전리층에서 소모되는 에너지 그리고 여기에 수반되는 열권의 온도상승 등의 형태로 예보하도록 고안되었다. 본 예보코드는 플레어 관측으로부터 태양풍 그리고 행성간자기장을 예측하는 부분과 추정된 태양풍파라미터로 표현되는 태양풍-자기권상호작용함수인 $\varepsilon$으로부터 상기 물리량들은 추정하는 부분으로 나누어져 있다. 1993년 11월 초에 발생한 자기폭풍에 이 예보코드를 적용하여 그 결과를 일본인공위성인 Geotail에 의한 태양풍관측결과와 지자기관측소에서 얻은 지자기 활동지수들과 비교하였다. 비록 많은 부분에서 아직 개선되어야할 여지가 발견되었지만 태양 플레어로 야기되는 지구근방 우주환경에 교란상태를 예측하는데 근사적이지만 본 예보모델이 사용될 수 있음을 확인하였다.