• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2516-2518
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• 2004

This paper proposes a stability condition in discrete-time affine Takagi-Sugeno (T-S) fuzzy systems with parametric uncertainties and then, introduces the design method of a fuzzy-model-based controller which guarantees the stability. The analysis is based on Lyapunov functions that are continuous and piecewise quadratic. The search for a piecewise quadratic Lyapunov function can be represented in terms of linear matrix inequalities (LMIs).

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.3
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• pp.184-189
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• 2006

This paper deals with a fractional model reduction for T-S fuzzy systems with time varying delayed states. A contractive coprime factorization of time delayed T-S fuzzy systems is defined and obtained by solving linear matrix inequalities. Using generalized controllability and observability gramians of the contractive coprime factor, a balanced state space realization of the system is derived. The reduced model will be obtained by truncating states in the balanced realization and an upper bound of model approximation error is also presented. In order to demonstrate efficacy of the suggested method, a numerical example is performed.

• Journal of applied mathematics & informatics
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• v.26 no.5_6
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• pp.1011-1020
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• 2008

The problem of finding Cramer rule for solutions of some restricted linear equation Ax = b has been widely discussed. Recently Wang and Qiao consider the following more general problem AXB = D, $R(X){\subset}T$, $N(X){\supset}\tilde{S}$. They present the solution of above general restricted matrix equation by using generalized inverses and give an explicit expression for the elements of the solution matrix for the matrix equation. In this paper we re-consider the restricted matrix equation and give an equivalent matrix equation to it. Through the equivalent matrix equation, we derive condensed Cramer rule for above restricted matrix equation. As an application, condensed determinantal expressions for $A_{T,S}^{(2)}$ A and $AA_{T,S}^{(2)}$ are established. Based on above results, we present a method for computing the solution of a kind of restricted matrix equation.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.11a
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• pp.161-163
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• 2017

다양한 연령층에서 시청자가 늘어나고 있는 개인방송에서도 VR 서비스가 확대되고 있다. 기존의 VR 방송은 360도 카메라로 촬영된 영상을 시청자들이 VR로 보거나 개인방송 크리에이터들이 HMD를 착용하고 콘텐츠를 플레이 하는 영상을 시청자들이 시청하도록 구성되어있다. 시청자들의 몰입감과 흥미를 더욱 유발하기 위해 본 논문에서는 시청자의 입장에서 크리에이터가 진행하는 방송도 시청할 수 있고, 그 콘텐츠를 직접 즐길 수 있는 선택적 방송 시스템을 제안한다. 제안된 시스템은 기존의 시스템보다 시청자로 하여금 몰임감을 향상시키고 참여 한계를 극복할 수 있다.

• Structural Engineering and Mechanics
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• v.43 no.2
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• pp.163-177
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• 2012

This paper presents a LMI(linear matrix inequality)-based fuzzy approach of modeling and active vibration control of geometrically nonlinear flexible plates with piezoelectric materials as actuators and sensors. The large-amplitude vibration characteristics and dynamic partial differential equation of a piezoelectric flexible rectangular thin plate structure are obtained by using generalized Fourier series and numerical integral. Takagi-Sugeno (T-S) fuzzy model is employed to approximate the nonlinear structural system, which combines the fuzzy inference rule with the local linear state space model. A robust fuzzy dynamic output feedback control law based on the T-S fuzzy model is designed by the parallel distributed compensation (PDC) technique, and stability analysis and disturbance rejection problems are guaranteed by LMI method. The simulation result shows that the fuzzy dynamic output feedback controller based on a two-rule T-S fuzzy model performs well, and the vibration of plate structure with geometrical nonlinearity is suppressed, which is less complex in computation and can be practically implemented.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.2
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• pp.191-197
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• 2006

This paper deals with a fault detection system design for nuclear steam generator water level control system. We expressed the nonlinear properties of the steam generator level system as a T-S fuzzy system with time varying uncertain parameters. We design a residual generator using a left coprime factorization of the T-S fuzzy model and a fault detection filter in order to improve the fault detection performance. We demonstrate the efficiency of the suggested design method via many computer simulations.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.384.1-384.1
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• 2002

The antifungal activities of the essential oils from Citrus borgamia. Ciderus atlantica. Cymbopogon ditratus, Eucalyptus globulus. Juniperus communis. Lavandula angustifolia. Melaeuca aterinfolia. Pelargonium graveolens. Pogestemon patchouli. Rosmarinus officinalis. Styrax tonkinensis. and Thymus vulgaris, which are recommended for the treatment of microbial infections in aromatherapy and complementary medicines. were tested against Trichophyton spp. The activities were measured by broth dilution method and disk diffusion assay. As the results, most of the test oils inhibited growth of T. tonsurans. T.mentagrophytes. T. ferugineum. and T. rubrum. Eapecially, the essential oils from C. atlantica. C. ditratus. e. globulus, and P. graveolens showed the strongest activity among the tested herb oils showing MICs between < 0.09 and 0.39 mg/ml.

• The Research Journal of the Costume Culture
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• v.24 no.5
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• pp.588-599
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• 2016

The primary aim of this study was to analyze the fashion trend of wearing T-shirts with slogans at home and abroad and to consider the social influence of these shirts on fashion. The research method was based on the documentary method and the existing literature, and the study range was limited to the period from the middle of the 20th century to the present. Slogan T-shirts played important roles because they make the wearers highly visible wherever they go. T-shirts with slogans not only intentionally expressed the wearers' views on multiple social issues but they also made those issues more visible, thereby encouraging society to deal with them. The T-shirts also helped to form a social consensus regarding the issues. For this reason we referred to slogan T-shirts as 'the social fashion' in this research. Regarding the results, the research found that T-shirts with slogans were a social fashion that conveyed real political slogans and thus influenced people's political beliefs. Second, they politicized the issues in public interests with the public perspective. Third, the purpose of slogan T-shirts was to help people express their personality publicly and thereby bond with other people who held similar sympathies. Furthermore, the T-shirts conveyed multiple meanings in each message.

• Korean Journal of Child Studies
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• v.5
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• pp.3-20
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• 1984

The purpose of this paper was to review critiques on methodological problems relating to Piaget's researches in terms of its scientific nature. On the basis of review of literature, the following problems were pointed out: 1. Notwithstanding Piaget's emphasis on the scientific requirement for verification, Piaget was against the deductive method typical of scientific verification. 2. Piaget's theory was so vague that it couldn't be falsified. 3. Piaget ignored criticism of his method, and this was viewed as unscientific in the eyes of most scientists. 4. Avoiding the antecedent-consequence sequence of scientific experimentation, Piaget took the descriptive, rather than the explanative nature. 5. Piaget didn't accept individual differences in cognitive style in his research paradigm. 6. Piaget's experimental procedures looked very simple but they were too complex to understand what was happening. 7. Although Piaget's major ideas treated the child as the active constructor of reality, the child's experimental tasks were structured by experimenter. 8. Piaget's clinical method depended heavily upon language although the procedures required manipulation of objects. 9. Piaget always justified his experiments in terms of protocois selected from all the responses obtained. However, these protocols may not be the most representative responses or behaviors showing the child's cognitive structure.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.409-412
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• 2000

Many researchers have been trying to evaluate the diffusion coefficient of chloride ion in concrete by using qualitative and quantitative electro-migration tests. Up to now, however, there has been no sufficient method to closely determine the diffusion coefficient of chloride ion through electro-migration test. In this paper, the diffusion coefficient of chloride ion in concrete was investigated through an electro-migration test, that is, AASHTO T 277, Dhir's method, Tang's method and Andrade's method. And the results of these test were compared with each other.