• EDISON SW 활용 경진대회 논문집
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• 제4회(2015년)
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• pp.400-404
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• 2015

2차원 물질인 metal mono chalcogenides(MMC) 중 GaS와 GaSe를 대상으로 하여 층과 층 사이의 van der Waals(vdW) 상호작용을 density functional theory(DFT) 계산을 이용해 연구하였다. Local density approximation(LDA)와 generalized gradient approximation (GGA)의 두 가지 다른 exchange correlation functional을 이용하고, 또한 두 개의 층 사이에 작용하는 van der Waals 상호작용을 고려한 LDA-D2, GGA-D2 계산을 수행하였다. 이와 같은 네 가지 방법으로 층간거리를 바꾸어 binding energy curve를 계산하였다. 그 결과 GGA-D2계산이 MMC의 층간 상호 작용을 가장 잘 기술하였다.

• Advances in aircraft and spacecraft science
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• 제2권3호
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• pp.233-248
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• 2015

Frame structures have been traditionally represented as an assembling of components, these last described within the beam theory framework. In the case of frames involving complex components in which classical beam theory could fail, 3D descriptions seem the only valid route for performing accurate enough analyses. In this work we propose a framework for frame structure analyses that proceeds by assembling the condensed parametric rigidity matrices associated with the elementary beams composing the beams involved in the frame structure. This approach allows a macroscopic analysis in which only the condensed degrees of freedom at the elementary beams interfaces are considered, while fine 3D parametric descriptions are retained for local analyses.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3495-3501
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• 2014

A novel crystal, the mono-protonated metformin acetate (1), was obtained and characterized by elemental analysis, IR spectroscopy and X-ray crystallography. It was found that one of the imino group in the metformin cation was protonated along with the proton transfer from the secondary amino group to the other imino group. Its crystal structure was then compared with the previously reported diprotonated metformin oxalate (2). The difference between them is that the mono-protonated metformin cations can be linked by hydrogen bonding to form dimers while the diprotonated metformin cations cannot. Both of them are stabilized by intermolecular hydrogen bonds to assemble a 3-D supermolecular structure. The four potential tautomer of the mono-protonated metformin cation (tautomers 1a, 1b, 1c and 1d) were optimized and their single point energies were calculated by Density Functional Theory (DFT) B3LYP method based on the Polarized Continuum Model (PCM) in water, which shows that the most likely existed tautomer in human cells is the same in the crystal structure. Based on the optimized structure, their Wiberg bond orders, Natural Population Analysis (NPA) atomic charges, molecular electrostatic potential (MEP) maps were calculated to analyze their electronic structures, which were then compared with the corresponding values of the diprotonated metformin cation (cation 2) and the neutral metformin (compound 3). Finally, the possible tautomeric mechanism of the mono-protonated metformin cation was discussed based on the observed phenomena.

• 한국정보과학회논문지:시스템및이론
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• 제26권8호
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• pp.1009-1023
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• 1999

이 논문은 재귀원형군 G(2^m , 2^k ) 그래프 이론적 관점에서 고찰하고 정점이 서로소인 경로에 관한 위상 특성을 제시한다. 재귀원형군은 1 에서 제안된 다중 컴퓨터의 연결망 구조이다. 재귀원형군 {{{{G(2^m , 2^k )의 서로 다른 두 노드 v와 w를 잇는 연결도 kappa(G)개의 서로소인 경로의 길이가 두 노드 사이의 거리d(v,w)나 혹은 G(2^m , 2^k )의 지름 \dia(G)에 비해서 얼마나 늘어나는지를 고려한다. 서로소인 경로를 재귀적으로 설계하는데, 그 길이는 k ge2일 때 d(v,w)+2^k-1과 \dia(G)+2^k-1의 최솟값 이하이고, k=1일 때 d(v,w)+3과 \dia(G)\+2의 최솟값 이하이다. 이 연구는 (2^m , 2^k )의 고장 감내 라우팅, 고장 지름이나 persistence의 분석에 이용할 수 있다.Abstract In this paper, we investigate recursive circulant G(2^m , 2^k ) from the graph theory point of view and present topological properties concerned with node-disjoint paths. Recursive circulant is an interconnection structure for multicomputer networks proposed in 1 . We consider the length increments of {{{{kappa(G)disjoint paths joining arbitrary two nodes v and win G(2^m , 2^k )compared with distance d(v,w)between the two nodes and diameter {{{{\dia(G)of G(2^m , 2^k ), where kappa(G)is the connectivity of G(2^m , 2^k ). We recursively construct disjoint paths of length less than or equal to the minimum of {{{{d(v,w)+2^k-1and \dia(G)+2^k-1for kge2 and the minimum of d(v,w)+3 and \dia(G)+2for k=1. This work can be applied to fault-tolerant routing and analysis of fault diameter and persistence of G(2^m , 2^k )

• 한국수학교육학회지시리즈D:수학교육연구
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• 제10권2호
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• pp.103-113
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• 2006

The mathematics instructional beliefs of a teacher include the exterior mathematics instructional beliefs and the internal mathematics instructional beliefs. These two kinds of beliefs are formed in two kinds of different situations. The situated theory thinks that beliefs are related with the situations; so, the two kinds of beliefs are showed in the different situations. The internal instructional mathematics beliefs effect on the actual mathematics instruction, they ought to be noticeable.

• 한국소음진동공학회논문집
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• 제15권4호
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• pp.457-464
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• 2005

A three-dimensional (3-D) method of analysis is presented for determining the free vibration frequencies and mode shapes of thick, complete (not truncated) conical shells of revolution, Unlike conventional shell theories, which are mathematically two-dimensional (2-D). the present method is based upon the 3-D dynamic equations of elasticity. Displacement components $u_{r},\;u_{z},\;and\;u_{\theta}$ in the radial, axial, and circumferential directions, respectively, are taken to be sinusoidal in time, periodic in , and algebraic polynomials in the r and z directions. Potential (strain) and kinetic energies of the conical shells are formulated, the Ritz method is used to solve the eigenvalue problem, thus yielding upper bound values of the frequencies by minimizing the frequencies. As the degree of the polynomials is increased, frequencies converge to the exact values. Convergence to four-digit exactitude is demonstrated for the first five frequencies of theconical shells. Novel numerical results are presented for thick, complete conical shells of revolution based upon the 3-D theory. Comparisons are also made between the frequencies from the present 3-D Ritz method and a 2-D thin shell theory.

• 한국전자파학회논문지
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• 제12권3호
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• pp.425-431
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• 2001

비유전율 ${\epsilon}_{r}$=36인 유전체를 이용한 무선 LAN용 개구 결합 마이크로스트립 원통형 유전체 공진 안테나(DRA)를 설계하고 제작하였다. 우선 급전 소자는 마이크로스트립 전송선로 이론을 이용하여 급전 선로 길이, 선로 폭, 슬롯 길이, 슬롯 폿과 스터브 길이을 계산하였다. 방사 소자는 원통형 유전체 cavity 이론을 이용하여 설계하였다. 제작된 원통형 DRA의 공진주파수는 2.449 GHz이고 VSWR, 반사 손실과 대역폭은 각각 1.009, -47dB 와 70MHz이다. 방사 패턴의 전후방비는 13dB이고 E면과 H 면의 3dB 빔폭은 각각 1$10^{\circ}$과 90$^{\circ}$이다.

• 한국산업정보학회논문지
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• 제12권2호
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• pp.68-78
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• 2007

D-클래스는 주어진 동치관계(equivalence relation)에 있는 $n{\times}n$ 불리언 행렬의 집합으로 정의된다. D-클래스 계산은 $n{\times}n$ 불리언 행렬의 전체 집합을 대상으로 이 집합에서 조합할 수 있는 모든 세 불리언 행렬 사이의 곱셈을 요구한다. 그러나 불리언 행렬에 대한 대부분의 연구는 단지 두 개의 불리언 행렬에 대한 효율적인 곱셈에 집중되었으며 모든 불리언 행렬 사이의 곱셈에 대한 연구는 최근에야 소수가 보이고 있다. 본 논문은 모든 세 개의 불리언 행렬 곱셈과 모든 D-클래스를 보다 효율적으로 계산할 수 있는 이론을 제시하고 이를 적용한 알고리즘과 실행결과에 대하여 논한다.

• 복식
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• 제60권3호
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• pp.26-43
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• 2010

The inflow of digital technology into the art, especially in the Fashion Illustration since 1990, makes the new aesthetics of the beginning of the 21 century which the Software aesthetics can be called. The meeting of technology and the art make us recall a great scientist and artist, Leonardo da Vinci in the Renaissance that the notion of the art and skill was unified, same as the ancient history. This study is purposed to expand the concept of the art for the broad exchange of the digital technology and art and for the extensive expression method of the modern fashion illustration. Having views on science theory of the beginning of the 20 century, Theory of Relativity which had given a lot of influence in the philosophy, the litterature and the art, as well as all the science, it makes a connection with the history of art in the beginning of the 20 century and the story of the digital art in the beginning of the 21 century. Firstly, the Fauvism and 2D is based on the expression of the glowing and bright color by the Principle of constancy of light velocity. Secondly, the Cubism and 3D is associated with the Special theory of relativity in the cyberspace which the space and the time are totally accorded. Thirdly, the Futurism and 4D is compared with the General theory of relativity which contains the material and the gravity. They are gradually evolved into the Interactive art and the Kinetic art by the digital technology in the profound cyberspace.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.30-43
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• 2021

In the 2D/1D method, a global adjoint CMFD based on the generalized equivalence theory is built to synthesize the 2D radial MOC adjoint and 1D axial NEM adjoint calculation and also to accelerate the iteration convergence of 3D whole-core adjoint transport calculation. Even more important, an advanced yet accurate two-level (TL) CMFD acceleration technique is proposed, in which an equivalent one-group adjoint CMFD is established to accelerate the multi-group adjoint CMFD and then to accelerate the 3D whole-core adjoint transport calculation efficiently. Based on these method, a new code is developed to perform 3D adjoint neutron flux calculation. Then a set of VERA and C5G7 benchmark problems are chosen to verify the capability of the 3D adjoint calculations and the effectiveness of TL CMFD acceleration. The numerical results demonstrate that acceptable accuracy of 2D/1D adjoint calculations and superior acceleration of TL CMFD are achievable.