• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.246-248
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• 2006

This paper is concerned with non-fragile guaranteed cost state feedback controller design algorithm for descriptor systems with time-varying delay and static state feedback controller with multiplicative uncertainty. The considered uncertainties are norm-bounded and time delay is time-varying. Under the condition of controller gain variations, conditions for the existence of controller satisfying asymptotic stability and non-fragility and controller design method are derived via LMI approach. Moreover, the measure of non-fragility and the upper bound to minimize guaranteed cost function are given.

• Bulletin of the Korean Mathematical Society
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• v.54 no.3
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• pp.715-729
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• 2017

In this paper, we investigate the existence and multiplicity of solutions for systems driven by two non-local integrodifferential operators with homogeneous Dirichlet boundary conditions. The main tools are the Saddle point theorem, Ekeland's variational principle and the Mountain pass theorem.

• Bulletin of the Korean Mathematical Society
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• v.50 no.6
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• pp.2089-2101
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• 2013

The aim of this paper is to introduce the notion of Lie recurrent structure Jacobi operator for real hypersurfaces in non-flat complex space forms and to study such real hypersurfaces. More precisely, the non-existence of such real hypersurfaces is proved.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.7
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• pp.496-501
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• 2016

This paper presents a design method of non-parallel distributed compensation (non-PDC) static output feedback controller for continuous- and discrete-time T-S fuzzy systems. The existence condition of static output feedback control law is represented in terms of linear matrix inequalities (LMIs). The proposed sufficient stabilizing condition does not need any transformation matrices and equality constraints and is less conservative than the previous result of [21].

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.159-166
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• 2000

Non-destructive out-hole tests, impact-echo and impact-response are widely applied to evaluate integrity of drilled shafts. In these tests, vibratory motions of drilled shafts are interpreted, which induced by impacts on the shaft head. In applying the tests to evaluating integrity of shaft, it has been attended whether the tests have resolutions enough to distinguish existence of slime at between the shaft end and a bearing soil deposit. To distinguish existence of slime by tests, modes of shaft vibrations need to be reasonably interpreted, which generally vary according to a shaft boundary condition such as, a free-free or a free-fixed condition. The boundary condition of a shaft is, however, found to be significantly affected by stiffness of soil deposits around shaft as well as penetration depths of shaft into a bearing soil deposit. Thus, these effects on the boundary condition of a shaft should be considered reasonably in interpreting test results to decide the existence of slime. To investigate the effects, in this study, vibratory motions of shafts constructed in various soil conditions and end penetration depths are examined analytically. Based on the studies, variations of boundary condition are characterized in terms of soil stiffness contrast between a shaft perimeter and a shaft end, and also the ratio of a penetration depth to a shaft length. The results can be applied to verify the applicability of tests to identify the slime.

• Korean Institute of Interior Design Journal
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• v.19 no.1
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• pp.27-36
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• 2010

The purpose of this study is to define concept and characteristics of "Unphenomenon", the design concept conceived by Shiro Kuramata who is a world renowned Japanese interior designer and to explore how his ideas were materialized in his works. This study 1) examines his experience during his childhood reflected in his essay The scenery of the Unphenomenon' and training in Kuwazawa Design Institute that made Shiro Kuramata a true interior designer, and also considers how his design philosophy had been built up and realized under the unique social situation at the time. 2) defines the concept and characteristics of "Unphenomenon" as substance of his design philosophy by surveying remarks in his books and comments made by people around him in press interviews. 3) concludes his own design method and uniqueness by analyzing his works based on them. As a result, the study has founded that 1) transparency as recognitive realization of existence and non-existence: non-existence of physical property, connotation, ambiguity 2) expression of uncommonness by correcting and reinterpreting common prejudices: flotation, distortion of scale and shape 3) realization of insubstantiality by removing and replacing material and shape: replacement into light, removal of the structure, multiple layers of meaning.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.5 no.1
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• pp.11-20
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• 2007

The purpose of this study were to analysis on quality properties of lower extremity of patient with stroke by the existence of the independent walking. We recruited fourteen adults after stroke(7 male, 7 female; mean age, 64y) for our study. The subjects were divided into two groups; independent walking group(3 male, 3 female) and non-independent walking group(4 male, 4 female). We used in this study included a B-mode ultrasonography scanner with a 7.5 MHz linea probe. During the experiment, the subject was seated in the chair. The echogenicity(density, white area index; WAI) of the tibialis anterior and rectus femoris muscles were measured on both sides of the leg. In both of the density and WAI, the tibialis anterior muscle were significant differences between paratic side and non-paratic side, the independent walking and non-independent walking group. However, in both of the density and WAI of the rectus femoris muscle were only significant differences between paratic side and non-paratic side. This study showed that stroke and the independent walking have influenced on quality properties of lower leg. Especially, the independent walking has influenced on the tibialis anterior muscle.

• Journal of applied mathematics & informatics
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• v.25 no.1_2
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• pp.35-50
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• 2007

In this work, optimal harvesting policy for the predator-prey system of three species with age-dependent and diffusion is discussed. Existence and uniqueness of non-negative solution to the system are investigated by using the fixed point theorem. The existence of optimal control strategy is discussed and optimality conditions are obtained. Our results extend some known criteria.

• Journal of the Korean Mathematical Society
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• v.40 no.5
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• pp.883-899
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• 2003

In this paper, we will introduce the general concepts of generalized multiobjective game, generalized weight Nash equilibria and generalized Pareto equilibria. Next using the fixed point theorems due to Idzik [5] and Kim-Tan [6] , we shall prove the existence theorems of generalized weight Nash equilibria under general hypotheses. And as applications of generalized weight Nash equilibria, we shall prove the existence of generalized Pareto equilibria in non-compact generalized multiobjective game.

• Journal of the Chungcheong Mathematical Society
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• v.27 no.1
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• pp.89-97
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• 2014

We study the existence of mild solutions for neutral differential equations with nonlocal conditions in the ${\alpha}$-norm.