• 제목/요약/키워드: elliptic integral

검색결과 46건 처리시간 0.027초

타원곡선에서 스칼라 곱의 고속연산 (A fast scalar multiplication on elliptic curves)

  • 박영호;한동국;오상호;이상진;임종인;주학수
    • 정보보호학회논문지
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    • 제12권2호
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    • pp.3-10
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    • 2002
  • Koblitz 타원곡선에서 스칼라 곱을 효율적으로 구현하기 위하여 프로베니우스 자기준동형 (Frobenius endomorphism)이 유용하게 사용된다. 스칼라 곱 연산시 스칼라를 이진 전개하는 대신에 프로베니우스 확장을 사용하여 고속연산을 가능하게 할 수 있으며 따라서 연산의 속도는 확장길이와 밀접한 관계가 있다. 본 논문은 스칼라의 프로베니우스 확장길이를 줄임으로써 스칼라 곱의 고속연산을 가능하게 하는 새로운 방법을 제안한다. 타원곡선의 위수를 노름(Norm)으로 갖는 원소대신 큰 소수 위수를 노름으로 갖는 원소를 사용하여 프로베니우스 확장길이를 최적화시키는 이 방법은 Solinas, Smart가 제안한 방법보다 프로베니우스 확장길이를 더 감소시킬 수 있다.

REMOVAL OF HYPERSINGULARITY IN A DIRECT BEM FORMULATION

  • Lee, BongJu
    • Korean Journal of Mathematics
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    • 제18권4호
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    • pp.425-440
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    • 2010
  • Using Green's theorem, elliptic boundary value problems can be converted to boundary integral equations. A numerical methods for boundary integral equations are boundary elementary method(BEM). BEM has advantages over finite element method(FEM) whenever the fundamental solutions are known. Helmholtz type equations arise naturally in many physical applications. In a boundary integral formulation for the exterior Neumann there occurs a hypersingular operator which exhibits a strong singularity like $\frac{1}{|x-y|^3}$ and hence is not an integrable function. In this paper we are going to remove this hypersingularity by reducing the regularity of test functions.

Numerical simulations of elliptic particle suspensions in sliding bi-periodic frames

  • Chung, Hee-Taeg;Kang, Shin-Hyun;Hwang, Wook-Ryol
    • Korea-Australia Rheology Journal
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    • 제17권4호
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    • pp.171-180
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    • 2005
  • We present numerical results for inertialess elliptic particle suspensions in a Newtonian fluid subject to simple shear flow, using the sliding bi-periodic frame concept of Hwang et al. (2004) such that a particulate system with a small number of particles could represent a suspension system containing a large number of particles. We report the motion and configurational change of elliptic particles in simple shear flow and discuss the inter-relationship with the bulk shear stress behaviors through several example problems of a single, two-interacting and ten particle problems in a sliding bi-periodic frame. The main objective is to check the feasibility of the direct simulation method for understanding the relationship between the microstructural evolution and the bulk material behaviors.

A NOTE ON SCATTERING OPERATOR SYMBOLS FOR ELLIPTIC WAVE PROPAGATION

  • Kim, Jeong-Hoon
    • 대한수학회논문집
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    • 제17권2호
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    • pp.349-361
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    • 2002
  • The ill-posed elliptic wave propagation problems can be transformed into well-posed initial value problems of the reflection and transmission operators characterizing the material structure of the given model by the combination of wave field splitting and invariant imbedding methods. In general, the derived scattering operator equations are of first-order in range, nonlinear, nonlocal, and stiff and oscillatory with a subtle fixed and movable singularity structure. The phase space and path integral analysis reveals that construction and reconstruction algorithms depend crucially on a detailed symbol analysis of the scattering operators. Some information about the singularity structure of the scattering operator symbols is presented and analyzed in the transversely homogeneous limit.

Large deflection behavior of a flexible circular cantilever arc device subjected to inward or outward polar force

  • Al-Sadder, Samir Z.
    • Structural Engineering and Mechanics
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    • 제22권4호
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    • pp.433-447
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    • 2006
  • The problem of very large deflection of a circular cantilever arc device subjected to inward or outward polar force is studied. An exact elliptic integral solution is derived for the two cases and the results are checked using large displacement finite element analysis via the ANSYS package by performing a new novel modeling simulation technique for this problem. Excellent agreements have been obtained between the exact analytical solution and the numerical approach. From this study, a design chart for engineers is developed to predict the required value for the inward polar force for the device to switch on for a given angle forming the circular arc (${\theta}_o$). This study has several interesting applications in mechanical engineering, integrated circuit technology, nanotechnology and especially in microelectromechanical systems (MEMs) such as a MEM circular device switch subjected to attractive or repulsive magnetic forces due to the attachments of two magnetic poles at the fixed and at the free end of the circular cantilever arc switch device.

다층타원 유전체주의 전자파 산란 해석 (An Analysis of Electromagnetic Wave Scattering for the Elliptic-Multi Layer Dielectric Cylinders)

  • 박동희;김정기
    • 한국전자파학회지:전자파기술
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    • 제2권3호
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    • pp.26-31
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    • 1991
  • The scattering property of TMz illuminated a elliptic dielectric cylinders with arbitrary cross section are analyzed by the boundary element techniques. The boundary element equations are for- mulated via Maxwell's equations, weighted residual of Green's theorem, and the boundary conditions. The unknown surface fields on the boundaries are then calculated by the boundary element integral equations. Once the surface fields are found, the scattered fields in far-zone and scattering widths (SW) are readily determined. To show the validity and usefulness of this formulation, computations are compared with those obtained using analytical method and one layer circular cylinder. As exten- sion to arbitrary cross-sectioned cylinders, plane wave scattering from a elliptic dielectric cylinders are numerically analyzed. A general computer program has been developed using the quadratic ele- ments(Higher order borndary elements) and the Gaussian quadrature.

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타원곡선상의 고속 곱셈연산을 위한 새로운 분해 알고리즘 (A new decomposition algorithm of integer for fast scalar multiplication on certain elliptic curves)

  • 박영호;김용호;임종인;김창한;김용태
    • 정보보호학회논문지
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    • 제11권6호
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    • pp.105-113
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    • 2001
  • 최근에 Gallant, Lambert, Vanstone은 소수체 위에 정의된 타원곡선이 효율적으로 계산 가능한 자기준동형을 가질 때 스칼라 곱을 가속화하는 방법을 제안하였다. 이 방법은 실제로 자기준동형의 특성다항식의 고유치를 사용하여 스칼라를 분해하는데 기반을 두고 있다. 본 논문에서는 그러한 타원곡선의 자기준동형 환의 원소를 이용하여 스칼라를 분해하는 개선된 알고리즘을 제안한다. 이 알고리즘은 Gallant 등의 알고리즘보다 속도면에서 효율적이며 분해성분들의 구체적인 상한 값을 줄 수 있다.

EXISTENCE AND NONEXISTENCE OF SOLUTIONS FOR CERTAIN SECOND-ORDER ODES

  • JU, HYEONG-KWAN
    • 호남수학학술지
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    • 제24권1호
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    • pp.25-33
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    • 2002
  • In this paper we have shown conditions of R for the existence of the solution to the problem of the type $-u''=ue^{{\varepsilon}u}$ on the interval (0, R) with boundary and other conditions as in $(1-{\varepsilon})-(4)$ for various ${\varepsilon}$.

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