• Journal of Institute of Control, Robotics and Systems
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• v.3 no.2
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• pp.109-114
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• 1997

In this paper, we present an output feedback $H^\infty$controller design method and derive the sufficient condition of the bounded real lemma for linear systems with multiple delays in states. For state delayed systems, sufficient conditions for the existence $\kappa$-th order $H^\infty$controllers are given in terms of three linear matrix inequalities(LMIs). Furthermore, we show how to construct such controllers from the positive definite solutions of their LMIs and given an example to illustrate the validitiy of the proosed design procedure.

• BMB Reports
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• v.30 no.3
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• pp.173-176
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• 1997

We isolated a cDNA clone that encodes a ribulose-1,5-bisphosphate carboxylase small subunit (rbcS) from spinach using a soybean rbcS cDNA as a probe. The small subunit consists of 180 amino acids including a transit peptide of 57 residues. Comparison of the amino acid sequence with those of other plant species shows a maximum of 70-80% identical residues. Southern blot analysis suggests the existence of multiple rbcS genes in the spinach genome. Northern blot analysis indicates that the rbcS gene is expressed predominantly in leaves and that the expression of the gene is induced by light.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.12 no.3
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• pp.161-169
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• 2008

We investigate the existence of solutions u(x, t) for perturbations of the elliptic system with Dirichlet boundary condition $$\array {L{\xi}+{\mu}g({\xi}+2{\eta})=f\;in\;{\Omega}}\\{L{\eta}+{\nu}g({\xi}+2{\eta})=f\;in\;{\Omega}}$$ (0.1) where $g(u)=Bu^+-Au^-$, $u^+=max\{u,\;0\}$, $u^-=max\{-u,\;0\}$, ${\mu}$, ${\nu}$ are nonzero constants and the nonlinearity $({\mu}+2{\nu})g(u)$ crosses the eigenvalues of the elliptic operator L.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.16-21
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• 2005

Photonic crystals, periodic structure with a high refractive index contrast modulation, have recently become very interesting platform for the manipulation of light. The existence of a photonic bandgap, a frequency range in which the propagation of light is prevented in all directions, makes photonic crystal very useful in application where the spatial localization of light is required, for example waveguide, beam splitter, and cavity. However, the fabrication of 3 dimensional photonic crystals is still difficult process. A concept that has recently attracted a lot of attention is a planar photonic crystal based on a dielectric membrane, suspended in the air and perforated with two dimensional lattice of hole. The fabrication of Si master with pillar structure using hot embossing process is investigated for two dimensional, low-index-contrast photonic crystal waveguide. From our research we show that the multiple stamp copy process proved to be feasible and useful.

• Communications for Statistical Applications and Methods
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• v.24 no.5
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• pp.481-492
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• 2017

This paper investigates a convergence rate of a test statistics given by two scale sampling method based on $A\ddot{i}t$-Sahalia and Jacod (Annals of Statistics, 37, 184-222, 2009). This statistics tests for longitudinal data having the existence of long memory dependence driven by fractional Brownian motion with Hurst parameter $H{\in}(1/2,\;1)$. We obtain an upper bound in the Kolmogorov distance for normal approximation of this test statistic. As a main tool for our works, the recent results in Nourdin and Peccati (Probability Theory and Related Fields, 145, 75-118, 2009; Annals of Probability, 37, 2231-2261, 2009) will be used. These results are obtained by employing techniques based on the combination between Malliavin calculus and Stein's method for normal approximation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.122-129
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• 2010

High-performance concrete (HPC) is a new terminology used in concrete construction industry. Several studies have shown that concrete strength development is determined not only by the water-to-cement ratio but also influenced by the content of other concrete ingredients. HPC is a highly complex material, which makes modeling its behavior a very difficult task. This paper aimed at demonstrating the possibilities of adapting artificial neural network (ANN) to predict the comprresive strength of HPC. Mahalanobis Distance (MD) outlier detection method used for the purpose increase prediction ability of ANN. The detailed procedure of calculating Mahalanobis Distance (MD) is described. The effects of outlier compared with before and after artificial neural network training. MD outlier detection method successfully removed existence of outlier and improved the neural network training and prediction performance.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.14 no.1
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• pp.1-16
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• 2010

An epidemic model with Classical Kermack-Mckendrick incidence rate under a limited resource for treatment is proposed to understand the effect of the capacity for treatment. We have assumed that treatment function is strictly increasing function of infective individuals and becomes constant when the number of infective is very large. Existence and stability of the disease free and endemic equilibrium are investigated, boundedness of the solutions are shown. Even in this simple version of the model, backward bifurcation and multiple epidemic steady states can be observed with some sets of parameter values. Hopf-bifurcation analyses are given and numerical examples are provided to help understanding.

• Bulletin of the Korean Mathematical Society
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• v.53 no.6
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• pp.1805-1821
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• 2016

In this paper, we are concerned with the nonlinear elliptic equations of the p(x)-Laplace type $$\{\begin{array}{lll}-div(a(x,{\nabla}u))+{\mid}u{\mid}^{p(x)-2}u={\lambda}f(x,u) && in\;{\Omega}\\(a(x,{\nabla}u)\frac{{\partial}u}{{\partial}n}={\lambda}{\theta}g(x,u) && on\;{\partial}{\Omega},\end{array}$$ which is subject to nonlinear Neumann boundary condition. Here the function a(x, v) is of type${\mid}v{\mid}^{p(x)-2}v$ with continuous function $p:{\bar{\Omega}}{\rightarrow}(1,{\infty})$ and the functions f, g satisfy a $Carath{\acute{e}}odory$ condition. The main purpose of this paper is to establish the existence of at least three solutions for the above problem by applying three critical points theory due to Ricceri. Furthermore, we localize three critical points interval for the given problem as applications of the theorem introduced by Arcoya and Carmona.

• Korean Journal of Mathematics
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• v.15 no.2
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• pp.149-165
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• 2007

We investigate the existence of multiple nontrivial solutions $u(x,t)$ for a perturbation $b[({\xi}-{\eta}+2)^+-2]$ of the hyperbolic system with Dirichlet boundary condition $$(0.1)\;L{\xi}={\mu}[({\xi}-{\eta}+2)^+-2]\;in\;({-{\frac{{\pi}}{2}}},{\frac{{\pi}}{2}}){\times}\mathbb{R},\\L{\eta}={\nu}[({\xi}-{\eta}+2)^+-2]\;in\;({-{\frac{{\pi}}{2}}},{\frac{{\pi}}{2}}){\times}\mathbb{R},$$, where $u^+$=max{u,o}, ${\mu}$, ${\nu}$ are nonzero constants. Here L is the wave operator in $\mathbb{R}^2$ and the nonlinearity $({\mu}-{\nu})[({\xi}-{\eta}+2)^+-2]$ crosses the eigenvalues of the wave operator.

• Korean Journal of Mathematics
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• v.18 no.4
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• pp.473-487
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• 2010

We investigate the existence of multiple nontrivial solutions (${\xi}$, ${\eta}$) for perturbations $g_1$, $g_2$ of the harmonic system with Dirichlet boundary condition $${\Delta}^2{\xi}+c{\Delta}{\xi}=g_1(2{\xi}+3{\eta})\;in\;{\Omega}\\{\Delta}^2{\eta}+c{\Delta}{\eta}=g_2(2{\xi}+3{\eta})\;in\;{\Omega}$$ where we assume that ${\lambda}_1$ < $c$ < ${\lambda}_2$, $g^{\prime}_1({\infty})$, $g^{\prime}_2({\infty})$ are finite. We prove that the system has at least three solutions under some condition on $g$.