• 오토저널
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• 제12권2호
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• pp.51-58
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• 1990

According to the developments of various composite materials, it seems to be very important to evaluate the strength and fracture behavior of composite materials. When the composite material is considered as orthotropic material, the characteristic equation of orthotropic material have complex roots. If characteristic roots are equal, the fundamental solutions of BEM become singular ones. This paper analyse the fundamental solutions of the singular problem of orthotropic material using the analogous method to isotropic material.

• 충청수학회지
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• 제20권4호
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• pp.449-455
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• 2007

We obtain a discrete version of a fundamental result by Yoshizawa related to the existence of almost periodic solutions of functional differential equations with finite delay.

• 대한수학회보
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• 제37권2호
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• pp.303-316
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• 2000

The Cauchy problem for degenerate parabolic equations with absorption is studied. We prove the existence of a fundamental solution. Also a Harnack type inequality is established and the existence and uniqueness of initial trace for nonnegative solutions is shown.

• 한국수학교육학회지시리즈A:수학교육
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• 제21권3호
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• pp.25-28
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• 1983

In this paper we examine some properties of spectral measures and try to establish a fundamental theorem on the existence of the solution of a generalized Volterra equation in a Hilbert space as the results.

• Earthquakes and Structures
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• 제10권2호
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• pp.389-408
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• 2016

Recently, seismic hazard analysis has become a very significant issue. New systems and available data have been also developed that could help scientists to explain the earthquakes phenomena and its physics. Scientists have begun to accept the role of uncertainty in earthquake issues and seismic hazard analysis. However, handling the existing uncertainty is still an important problem and lack of data causes difficulties in precisely quantifying uncertainty. Ground Motion Prediction Equation (GMPE) values are usually obtained in a statistical method: regression analysis. Each of these GMPEs uses the preliminary data of the selected earthquake. In this paper, a new fuzzy method was proposed to select suitable GMPE at every intensity (earthquake magnitude) and distance (site distance to fault) according to preliminary data aggregation in their area using ${\alpha}$ cut. The results showed that the use of this method as a GMPE could make a significant difference in probabilistic seismic hazard analysis (PSHA) results instead of selecting one equation or using logic tree. Also, a practical example of this new method was described in Iran as one of the world's earthquake-prone areas.

• 호남수학학술지
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• 제14권1호
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• pp.93-98
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• 1992

• 대한수학회지
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• 제41권3호
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• pp.535-565
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• 2004

In this paper we consider the notion of ξ-invariant or (equation omitted)-invariant real hypersurfaces in a complex two-plane Grassmannian $G_2$( $C^{m+2}$) and prove that there do not exist such kinds of real hypersurfaces in $G_2$( $C^{m+2}$) with parallel second fundamental tensor on a distribution ζ defined by ζ = ξ U(equation omitted), where(equation omitted) = Span ｛ξ$_1$, ξ$_2$, ξ$_3$｝.X>｝.

• 대한수학회지
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• 제44권2호
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• pp.443-453
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• 2007

We study the equation of a membrane with strong viscosity. Based on the variational formulation corresponding to the suitable function space setting, we have proved the fundamental results on existence, uniqueness and continuous dependence on data of weak solutions.

• 대한수학회논문집
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• 제31권4호
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• pp.729-743
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• 2016

In the current work, the intuitionistic fuzzy version of Hyers-Ulam stability for a nonic functional equation by applying a fixed point method is investigated. This way shows that some fixed points of a suitable operator can be a nonic mapping.

• 전기의세계
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• 제26권4호
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• pp.41-53
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• 1977

With the equivalent series circuit analyzed aby revolving field theory and drawn by using the equivalent circuit constant ratios in capacitor motor with windings not in quadrature having space harmonics in its magnetic field (the above ratios are the equivalent circuit constants for the fundamental flux to the magnetizing reactance of the circuit), the equation for the alternating torque with twice line freequency in the motor is directly derived, and the alternating torque is measured with the self-made stator vibration angle amplitude measuring apparatus that is composed of a pickup, filter, photoelectric pickoff etc. The measured values satisfactorily compared with computed values. The properties of the alternating torque characteristics for respective harmonic fluxes and the r5esultant alternating torque characteristic, the effects of the alternating torque characteristics for respective harmonic fluxes on the resultant alternating torque characteristic, the effects of the variation in the motor constants and the equivalent circuit constant ratios for the fundamental flux on the alternating torque characteristics for respective harmonic fluxes and the resultant alternating torque characteristic, are made clear, applying the equation. There exist the optimum values of the motor constants and the equivalent circuit constant ratios for the fundamental flux for decreasing the alternating torque, and the value could be determined in design by the method presented in this paper.