• Journal of applied mathematics & informatics
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• v.14 no.1_2
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• pp.193-212
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• 2004

A new model of generalized thermoelasticity equations for isotropic media with temperature-dependent mechanical properties is established. The modulus of elasticity is taken as a linear function of reference temperature. The present model is described both generalizations, Lord Shulman (L-S) theory with one relaxation time and Green-Lindsay (G-L) with two relaxation times, as well as the coupled theory, instantaneously. The method of the matrix exponential, which constitutes the basis of the state space approach of modern control theory, applied to two-dimensional equations. Laplace and Fourier integral transforms are used. The resulting formulation is applied to a problem of a thick plate subject to heating on parts of the upper and lower surfaces of the plate that varies exponentially with time. Numerical results are given and illustrated graphically for the problem considered. A comparison was made with the results obtained in case of temperature-independent modulus of elasticity in each theory.

• Kyungpook Mathematical Journal
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• v.59 no.3
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• pp.563-589
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• 2019

Let W and V be manifolds of dimension m + 2, M a locally flat submanifold of V whose dimension is m. Let $f:W{\rightarrow}V$ be a homotopy equivalence. The problem we study in this paper is the following: When is f homotopic to another homotopy equivalence $g:W{\rightarrow}V$ such that g is transverse regular along M and such that $g{\mid}g^{-1}(M):g^{-1}(M){\rightarrow}M$ is a simple homotopy equivalence? $L{\acute{o}}pez$ de Medrano (1970) called this problem the weak h-regularity problem. We solve this problem applying the codimension two surgery theory developed by the author (1973). We will work in higher dimensions, assuming that $$m{\geq_-}5$$.

• Journal of the Korean Mathematical Society
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• v.28 no.1
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• pp.99-125
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• 1991

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.620-620
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• 2013

When $MoS_2$ is thinned to single layer (1L), photoluminescence (PL) quantum yield drastically increases due to emergence of direct band gap. A recent theory predicts that the electronic structure of 1L $MoS_2$ is very sensitive to its lattice constants. We investigated the response of 1L $MoS_2$ to biaxial tensile strain using spatially resolved PL and Raman spectroscopy. Changes in the lattice constants were monitored by the Raman frequency of the in-plane ($E^1{_2g}$) mode. Systematic correlations between PL and Ramanspectral features, revealed in the preliminary results, will be further tested with samples on other substrates and against thermal stress. The results will also be discussed in regard to the theory which predicts that 1L $MoS_2$ becomes an indirect semiconductor at small tensile strain and turns metallic when further extended.

• Geomechanics and Engineering
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• v.28 no.4
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• pp.347-358
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• 2022

The main concern of this article is to discuss the problem of a two-temperature fiber-reinforced micropolar thermoelastic medium with voids under the effect rotation, mechanical force in the context four different theories with memory-dependent derivative (MDD) and variable thermal conductivity. The three-phase-lag model (3PHL), dual-phase-lag model (DPL), Green-Naghdi theory (G-N II, G-N III), coupled theory, and the Lord-Shulman theory (L-S) are employed to solve the present problem. Analytical expressions of the physical quantities are obtained by using Laplace-Fourier transforms technique. Numerical results are shown graphically and the results obtained are analyzed. The most significant points are highlighted.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.213-215
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• 1996

Until now the test of LIM have been mainly experimented for a small capacity LIM. This paper deals with the static characteristics of a large capacity LIM which is designed for MAGLEV. And we developed the simulation program using electro-magnetic field theory and equivalent circuit method. Hence it is evaluated the performance of a large capacity LIM. Also this paper predicts the dynamic characteristics of LIM with the proposed simulation program.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.8
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• pp.999-1007
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• 1999

이 논문은 재귀원형군 G(2^m , 2^k )를 그래프 이론적 관점에서 고찰하고 정점이 서로소인 사이클과 그래프 invariant에 관한 위상 특성을 제시한다. 재귀원형군은 1 에서 제안된 다중 컴퓨터의 연결망 구조이다. 재귀원형군 {{{{G(2^m , 2^k )가 길이 사이클을 가질 필요 충분 조건을 구하고, 이 조건하에서 G(2^m , 2^k )는 가능한 최대 개수의 정점이 서로소이고 길이가l`인 사이클을 가짐을 보인다. 그리고 정점 및 에지 채색, 최대 클릭, 독립 집합 및 정점 커버에 대한 그래프 invariant를 분석한다.Abstract In this paper, we investigate recursive circulant G(2^m , 2^k ) from the graph theory point of view and present topological properties of G(2^m , 2^k ) concerned with vertex-disjoint cycles and graph invariants. Recursive circulant is an interconnection structure for multicomputer networks proposed in 1 . A necessary and sufficient condition for recursive circulant {{{{G(2^m , 2^k ) to have a cycle of lengthl` is derived. Under the condition, we show that G(2^m , 2^k ) has the maximum possible number of vertex-disjoint cycles of length l`. We analyze graph invariants on vertex and edge coloring, maximum clique, independent set and vertex cover.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.8
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• pp.426-431
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• 2005

A many-to-many k-disjoint path cover (k-DPC) of a graph G is a set of k disjoint paths joining k distinct source-sink pairs in which each vertex of G is covered by a path. In this paper, we investigate many-to-many 2-DPC in a double loop network G(mn;1,m), and show that every nonbipartite G(mn;1,m), $m{\geq}3$, has 2-DPC joining any two source-sink pairs of vertices and that every bipartite G(mn;1,m) has 2-DPC joining any two source-sink pairs of black-white vertices and joining any Pairs of black-black and white-white vertices. G(mn;l,m) is bipartite if and only if n is odd and n is even.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.2889-2894
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• 2013

A new complex [$Ni(phen)(C_9H_8Br_2NO_3)_2{\cdot}2CH_3OH{\cdot}2H_2O$] [phen: 1,10-phenanthroline $C_9H_8Br_2NO_3$: 3,5-dibromo-L-tyrosine] was synthesized and characterized by IR, elemental analysis and single crystal X-ray diffraction. X-ray crystallography shows that Ni(II) ion is six-coordinated. The Ni(II) ion coordinates with four nitrogen atoms and two oxygen atoms from three ligands, forming a mononuclear Ni(II) complex. The crystal crystallizes in the Orthorhombic system, space group $P2_12_12$ with a = 12.9546 ${\AA}$, b = 14.9822 ${\AA}$, c = 9.9705 ${\AA}$, V = 1935.2 ${\AA}$, Z = 1, F(000) = 1008, S = 0.969, ${\rho}_{calcd}=1.742g{\cdot}cm^{-3}$, ${\mu}=4.688mm^{-1}$, $R_1$ = 0.0529 and $wR_2$ = 0.0738 for 3424 observed reflections (I > $2{\sigma}(I)$). Theoretical study of the title complex was carried out by density functional theory (DFT) method and the B3LYP method employing the $6-3l+G^*$ basis set. The energy gap between HOMO and LUMO indicates that this complex is prone to interact with DNA. CCDC: 908041.

• Communications of the Korean Mathematical Society
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• v.39 no.1
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• pp.149-160
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• 2024

In this paper, we give sufficient conditions for the generalized Ornstein-Uhlenbeck operators perturbed by regular potentials and inverse square potentials A_Φ,G,V,c=∆-∇Φ·∇+G·∇-V+c|x|^-2 with a suitable domain generates a quasi-contractive, positive and analytic C₀-semigroup in L^p(ℝ^N , e^-Φ(x)dx), 1 < p < ∞. The proofs are based on an L^p-weighted Hardy inequality and perturbation techniques. The results extend and improve the generation theorems established by Metoui [7] and Metoui-Mourou [8].