• 한국정보통신학회논문지
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• 제2권4호
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• pp.653-660
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• 1998

본 연구는 시간영역 유한 차분법(finite difference-time domain method:FDTD)을 이용하여 마이크로스트립 배열 안테나의 전자계 특성들을 해석한다. 직각좌표계에서 맥스웰 방정식의 유한차분 방정식을 정의하였으며, 자유공간과 같은 무한영역해석을 위해서 Mur의 흡수경계조건을 이용하였다 마이크로스트립 배열 안테나를 단위격자 구조로 모델링한 후 시간영역에서 필드분포를 도시하였다.

• 대한수학회지
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• 제41권2호
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• pp.379-396
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• 2004

In this article, we study rotation surfaces in the 4-dimensional pseudo-Euclidean space E$_2$$^4$. Also, we obtain the complete classification theorems for the flat rotation surfaces with finite type Gauss map, pointwise 1-type Gauss map and an equation in terms of the mean curvature vector. In fact, we characterize the flat rotation surfaces of finite type immersion with the Gauss map and the mean curvature vector field, namely the Gauss map of finite type, pointwise 1-type Gauss map and some algebraic equations in terms of the Gauss map and the mean curvature vector field related to the Laplacian of the surfaces with respect to the induced metric.

• 대한임베디드공학회논문지
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• 제11권4호
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• pp.227-233
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• 2016

Efficient finite field arithmetic is essential for fast implementation of error correcting codes and cryptographic applications. Among the arithmetic operations over finite fields, the multiplication is one of the basic arithmetic operations. Therefore an efficient design of a finite field multiplier is required. In this paper, two new bit-parallel systolic multipliers for $GF(2^m)$ fields defined by AOP(all-one polynomial) have proposed. The proposed multipliers have a little bit greater space complexity but save at least 22% area complexity and 13% area-time (AT) complexity as compared to the existing multipliers using AOP. As compared to related works, we have shown that our multipliers have lower area-time complexity, cell delay, and latency. So, we expect that our multipliers are well suited to VLSI implementation.

• 대한수학회보
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• 제29권2호
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• pp.277-283
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• 1992

Let GF(q) be a finite field with q elements where q=p$^{n}$ for a prime number p and a positive integer n. Consider an arbitrary function .phi. from GF(q) into GF(q). By using the Largrange's Interpolation formula for the given function .phi., .phi. can be represented by a polynomial which is congruent (mod x$^{q}$ -x) to a unique polynomial over GF(q) with the degree < q. In [3], Wells characterized all polynomial over a finite field which commute with translations. Mullen [2] generalized the characterization to linear polynomials over the finite fields, i.e., he characterized all polynomials f(x) over GF(q) for which deg(f) < q and f(bx+a)=b.f(x) + a for fixed elements a and b of GF(q) with a.neq.0. From those papers, a natural question (though difficult to answer to ask is: what are the explicit form of f(x) with zero terms\ulcorner In this paper we obtain the exact form (together with zero terms) of a polynomial f(x) over GF(q) for which satisfies deg(f) < p$^{2}$ and (1) f(x+a)=f(x)+c for the fixed nonzero elements a and c in GF(q).

• 대한수학회보
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• 제52권6호
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• pp.2011-2023
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• 2015

This paper determines the structures of one-homogeneous weight codes over finite chain rings and studies the algebraic properties of these codes. We present explicit constructions of one-homogeneous weight codes over finite chain rings. By taking advantage of the distance-preserving Gray map defined in [7] from the finite chain ring to its residue field, we obtain a family of optimal one-Hamming weight codes over the residue field. Further, we propose a generalized method that also includes the examples of optimal codes obtained by Shi et al. in [17].

• 대한전기학회논문지
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• 제36권11호
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• pp.777-782
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• 1987

A new composite method of finite element and boundary integral methods is presented to solve the two dimensional magnetostatic field problems with open boundary. The method can deal with the current source of the boundary integral regin where the boundary integral method is applied, and also Neumann and Dirichlet boundary conditions at the interfacial boundary between the boundary integral region and the finite element region where the finite element method is applied. The new approach has been applied to a simple linear problem to verify the usefulness. It is shown that the proposed algorithm gives more accurate results than the finite element methed under the same elementdiscretization.

• 한국전자통신학회논문지
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• 제6권3호
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• pp.389-395
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• 2011

타원곡선 암호법(ECC)은 RSA나 ElGamal 암호법에 비하여 1/6정도의 열쇠(key) 크기로 동일한 안전도를 보장하므로, 메모리 용량이나 프로세서의 파워가 제한된 휴대전화기(cellular phone), 스마트카드, HPC(small-size computers) 등에 더욱 효과적인 암호법이다. 본 논문에서는 효과적인 타원곡선 암호법에 많이 사용되는 유한체위에서의 연산방법을 설명하고, Weil의 강하공격법(descent attack)에 안전하면서, 연산속도를 최대화하는 유한체의 합성체를 구축하여, 그 합성체위에서의 고속 연산기를 제안하려고 한다.

• 한국분말재료학회지
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• 제27권4호
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• pp.318-324
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• 2020

In the present work, an explicit finite element analysis technique is introduced to analyze the thermal stress fields present in the additive manufacturing process. To this purpose, a finite element matrix formulation is derived from the equations of motion and continuity. The developed code, NET3D, is then applied to various sample problems including thermal stress development. The application of heat to an inclusion from an external source establishes an initial temperature from which heat flows to the surrounding body in the sample problems. The development of thermal stress due to the mismatch between the thermal strains is analyzed. As mass scaling can be used to shorten the computation time of explicit analysis, a mass scaling of 108 is employed here, which yields almost identical results to the quasi-static results.

• 대한수학회보
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• 제59권6호
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• pp.1523-1537
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• 2022

We present a new square root algorithm in finite fields which is a variant of the Pocklington-Peralta algorithm. We give the complexity of the proposed algorithm in terms of the number of operations (multiplications) in finite fields, and compare the result with other square root algorithms, the Tonelli-Shanks algorithm, the Cipolla-Lehmer algorithm, and the original Pocklington-Peralta square root algorithm. Both the theoretical estimation and the implementation result imply that our proposed algorithm performs favorably over other existing algorithms. In particular, for the NIST suggested field P-224, we show that our proposed algorithm is significantly faster than other proposed algorithms.

• 대한수학회보
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• 제61권1호
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• pp.45-64
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• 2024

Let G be a finite group, K a split field for G, and L a linear map from K[G] to K. In our paper, we first give sufficient and necessary conditions for Ker L and Ker L ∩ Z(K[G]), respectively, to be Mathieu-Zhao spaces for some linear maps L. Then we give equivalent conditions for Ker L to be Mathieu-Zhao spaces of K[G] in term of the degrees of irreducible representations of G over K if G is a finite Abelian group or G has a normal Sylow p-subgroup H and L are class functions of G/H. In particular, we classify all Mathieu-Zhao spaces of the finite Abelian group algebras if K is a split field for G.