• Journal of applied mathematics & informatics
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• 제12권1_2호
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• pp.429-436
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• 2003

We study the asymptotic equivalence between the nonlinear differential system $\chi$'(t) = f(t, $\chi$(t)) and its variational system ν'(t) = f$\chi$(t, 0)ν(t) by using the comparison principle and notion of strong stability.

• 대한수학회논문집
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• 제20권2호
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• pp.351-358
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• 2005

We study asymptotic equivalence between nonlinear difference system $$\Delta\chi(n)=f(n,\chi(n))$$ and its variational system $${\Delta}v(n)=f_{\chi}(n,0)v(n)$$.

• 대한수학회보
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• 제44권1호
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• pp.177-184
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• 2007

We study the asymptotic behavior of nonlinear Volterra difference system $$x(n+1)=f(n,x(n))+{\sum\limits^{n}_{s=n_{o}}\;g(n,s,x(s)),\;x(n_{o})=xo$$ by using the resolvent matrix R(n, m) of the corresponding linear Volterra system and the comparison principle.

• 한국전자파학회논문지
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• 제9권5호
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• pp.614-620
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• 1998

본 논문에서는 타원형 커루게이트 도파관의 전파 및 복사특성을 이론적으로 해석한다. 타원형 원통 좌표계에서의 파동방정식의 해는 제1종 및 제2종의 Mathieu함수들로 얻어진다. 타원형 커루게이트 도파관의 전계와 자계들은 반경방향과 각 방향의 Mathieu함수들의 곱의 급수로 나타낼 수 있다. 슬랏 영역과 안쪽 영역의 경계면에서 임피던스 매칭 방법을 사용하여 특성 방정식을 얻는다. 타원형 커루게이트도파관에서의 주모드인 $HE_{11}$모드에 대한 특성방정식을 풀어 어퍼춰에서의 전자계를 계산하고, 또 계의 등가원리(field equivalence principle)를 이용하여 타원형 커루게이트 도파관에서의 복사패턴을 계산한다.

• 전자공학회논문지A
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• 제32A권9호
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• pp.1236-1243
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• 1995

The propagation characteristics of the symmetric and the asymmetric shielded coplanar waveguide with finite metallization thickness is analyzed by boundary integral method employing the equivalence principle. Since the Green's function and the basis functions are composed of sinusoidal functions, the integration in Galerkin's method is solved analytically. The propagation constants of the fundamental and the first higher order mode are obtained and the effects of strip thickness, substrate permittivity, and the asymmetry of the structure are calculated.

• 대한전자공학회논문지
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• 제27권5호
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• pp.666-671
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• 1990

The characteristics of the corrugated conical horn antenna for the satellite communication earth station operating at C band is analyzed and its radiation patterns is measured. We obtain the characterstic equations for corrugated horn in the condition that the balanced hybrid mode is formed on born aperture and calculate radiation patterns in the Fresnel region from the aperture integral expressions obtained by the equivalence principle. The radiation patterns which are calculated for the frequency of 3.85GHz and 6.18GHz are well agreed with the measured data.

• 전자공학회논문지D
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• 제35D권2호
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• pp.19-24
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• 1998

The problem of Smith-Purcell radiation by a strip grating over a groundeddielectric slabl is analyzed by use of the equivalence principle, Floquet's theorem, and the method of moment. the relative radiation intensities of the space harmonics, computed by use of the proposed method, for the appropriately chosen charge velocities and grating dimensions are presented. In particular, some relationships between the smith-purcell radiation and the leaky-wave radiation in the proposed geometry are investigated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.18-21
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• 1987

The problem of electromagnetic scattering from arbitrarily shaped lossy dielectric bodies of revolution is studied. Two coupled vector integral equations are formulated from the potential formulas, the equivalence principle and boundary condition. The unknown surface currents (both electric and magnetic) can be found by the moment method, Galerkins's procedure. After the surface currents are determined, the scattering pattern can be evaluated.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2002년도 추계 학술발표회 논문집
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• pp.293-298
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• 2002

We propose an improved version of Kim (2000) to the effect that in principle we may deal with a graphical model of any size. Kim (2000) proposed a method of estimating parameters for a model of categorical variables which is too large to handle as a single model. We applied the proposed method to a simulated data of 158 binary variables.

• 한국수학사학회지
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• 제32권1호
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• pp.17-25
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• 2019

This essay elucidates the way the geometries of space-time theories explain material bodies' motions. A conventional attempt to interpret the way that space-time geometry explains is to consider the geometrical structure of space-time as involving a causally efficient entity that directs material bodies to follow their trajectories corresponding to the laws of motion. Newtonian substantival space is interpreted as an entity that acts but is not acted on by the motions of material bodies. And Einstein's curved space-time is interpreted as an entity that causes the motions of bodies. This essay argues against this line of thought and provides an alternative understanding of the way space-time geometry explain the laws of motion. The workings of the way that Newton's flat and Einstein's curved space-time explains the law of motion is such that space-time geometry encodes the principle of inertia which specifies straight lines of moving bodies.