• Journal of the Optical Society of Korea
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• v.6 no.3
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• pp.96-99
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• 2002

We give a brief overview of nonlinear localized modes in photonic crystals. We explain how photonic crystals can potentially be important in making small scale active devices which operate in an all optical way. Two models to approach nonlinear photonic crystals, the coupled mode theory and the discrete lattice theory using a Green's function, are explained.

• Journal for History of Mathematics
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• v.15 no.2
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• pp.175-181
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• 2002

Since Noether has consolidated the structural approach to the study of algebra, the lattice theory has reemerged as a tool for the structural study for algebra and its own right as well in 1930s. We investigate the process which the mathematical structures made their foundations in Mathematics through the lattice theory in the period.

• Journal of the Korean Institute of Intelligent Systems
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• v.1 no.2
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• pp.16-34
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• 1991

It has been widely accepted that expert systems must reason from multiple sources of information that is to some degree evidential - uncertain, imprecise, and occasionally inaccurate - called evidential information. Evidence theory (Dempster/Shafet theory) provides one of the most general framework for representing evidential information compared to its alternatives such as Bayesian theory or fuzzy set theory. Many expert system applications require evidence to be specified in the continuous domain - such as time, distance, or sensor measurements. However, the existing evidence theory does not provide an effective approach for dealing with evidence about continuous variables. As an extension to Strat's pioneeiring work, this paper provides a new combination rule, a new method for mass function transffrmation, and a new method for rendering joint mass fuctions which are of great utility in evidence theory in the continuous domain.

• Advances in aircraft and spacecraft science
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• v.7 no.2
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• pp.115-134
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• 2020

This paper proposes a bending analysis for a functionally graded piezoelectric (FGP) plate through utilizing a two-variable shear deformation plate theory under simply-supported edge conditions. The number of unknown functions used in this theory is only four. The electric potential distribution is assumed to be a combination of a cosine function along the cartesian coordinate. Applying the analytical solutions of FGP plate by using Navier's approach and the principle of virtual work, the equilibrium equations are derived. The paper also discusses thoroughly the impact of applied electric voltage, plate's aspect ratio, thickness ratio and inhomogeneity parameter. Results are compared with the analytical solution obtained by classical plate theory, first-order-shear deformation theory, higher-order shear deformation plate theories and quasi-three-dimensional sinusoidal shear deformation plate theory.

• Advances in nano research
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• v.12 no.6
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• pp.617-627
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• 2022

In the current study, the nonlinear impact of the Von-Kármán theory on the vibrational response of nonhomogeneous structures of functionally graded (FG) nano-scale tubes is investigated according to the nonlocal theory of strain gradient theory as well as high-order Reddy beam theory. The inhomogeneous distributions of temperature-dependent material consist of ceramic and metal phases in the radial direction of the tube structure, in which the thermal stresses are applied due to the temperature change in the thickness of the pipe structure. The general motion equations are derived based on the Hamilton principle, and eventually, the acquired equations are solved and modeled by the Meshless approach as well as a computer simulation via intelligent mathematical methodology. The attained results are helpful to dissect the stability of the MEMS and NEMS.

• International Journal of Control, Automation, and Systems
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• v.2 no.4
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• pp.463-474
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• 2004

Game theory is a method of mathematical analysis developed to study the decision making process. In 1928, Von Neumann mathematically proved that every two-person, zero-sum game with many pure finite strategies for each player is deterministic. In the early 50's, Nash presented another concept as the basis for a generalization of Von Neumann's theorem. Another central achievement of game theory is the introduction of evolutionary game theory, by which agents can play optimal strategies in the absence of rationality. Through the process of Darwinian selection, a population of agents can evolve to an Evolutionary Stable Strategy (ESS) as introduced by Maynard Smith in 1982. Keeping pace with these game theoretical studies, the first computer simulation of coevolution was tried out by Hillis. Moreover, Kauffman proposed the NK model to analyze coevolutionary dynamics between different species. He showed how coevolutionary phenomenon reaches static states and that these states are either Nash equilibrium or ESS in game theory. Since studies concerning coevolutionary phenomenon were initiated, there have been numerous other researchers who have developed coevolutionary algorithms. In this paper we propose a new coevolutionary algorithm named Game theory based Coevolutionary Algorithm (GCEA) and we confirm that this algorithm can be a solution of evolutionary problems by searching the ESS. To evaluate this newly designed approach, we solve several test Multiobjective Optimization Problems (MOPs). From the results of these evaluations, we confirm that evolutionary game can be embodied by the coevolutionary algorithm and analyze the optimization performance of our algorithm by comparing the performance of our algorithm with that of other evolutionary optimization algorithms.

• Philosophy of Education
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• no.39
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• pp.191-221
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• 2009

The aim of this study is to analyse of elements and structure of consciousness theory in the 1887 Psychology written by John Dewey, and to research its educational implications. Conclusions are as follows: Firstly, consciousness theory articulated in first edition of Dewey's Psychology was influenced by neo-Hegelian G. S. Hall, and then characteristics of its theory was metaphysical and idealistic. But after of researching the work of William James, his approach to consciousness changed surprisingly from idealistic to experimental. His experimental approach and scientific attitude to it influenced the formation and development of advanced theories in his epistemology, axiology and pedagogy. Secondly, the structure of consciousness expressed by Dewey has three forms such as knowledge, feeling and will(or volition). This forms are too dynamic and unitary. Dewey considered cognition, feeling, will to be integral functions of each self. The tripartite functions of self, moreover, are unified in will. In other word, will combines subjective feeling and objective knowledge as one self. Will regulates impulse because it powers some stimulus into activity of self. In this view point, his theory of consciousness differs from traditional theories about consciousness for emphasizing dynamic relations and functions. Thirdly, Dewey's theory of consciousness will give some important implications to educational field. It is necessary to fundamental arguments about conscious conditions of learners as a human. For it is impossible to establish some aim of learning, to organize meaningful contents of learning, and also to create some effective methods of learning without consideration of this conditions. And it is important to construct and organize the contents and methods of learning for widening and deepening of educational experiences. Then consciousness and experiences of learners interact each other, so then they will produce some meaningful results of learning in this process.

• Journal of the Daesoon Academy of Sciences
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• v.21
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• pp.409-452
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• 2013

This paper aims to cast light on the theoretical characteristics of Korean new religions' utopian theory from the perspective of theology and apply the findings to the utopian theory of the new religions in Korea. The utopian theory of the new religions in Korea occurred to meet people's aspiration towards a new world on the background of the national ordeal and its consequential psychology in the late Chosun dynasty. As a result, it has the characteristics of a shift from a pure religious framework to participation in reality to realize religious ideals 'right here, right now'. Thus, it basically defined an utopian theory as the product of a society and history, and explained the utopian theory as the projection of the thoughts about current conflicts. However, an approach in this way may leave the likelihood that the individual characteristics of Daesoonjinrihoe would be overlooked and the utopian theory would be limited to the byproduct of the age, only. Thus, this paper has dealt with the religious experience of the founders as the lead of discussion, not a sociological approach. In this context, the religious experience of founders can be more significant clues to view the characteristics of an utopian theory. This directivity of a study can be understood as an attempt to improve the previous sociological methodologies, the leading discourses, and to contribute to the different perspectives on an understanding of the utopian theories of Daesoonjinrihoe. Furthermore, this paper is anticipated to give salience to the individual characteristics reflected in the new religions in Korea and to enhance its status in the history of thoughts, not as the trend of the thought limited to the past.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.433-437
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• 2003

Quantitative Feedback Theory (QFT) is one of effective methods of robust controller design. In QFT design we can considers the phase information of the perturbed plant so it is less conservative than $H_{\infty}$ and ${\mu}$-synthesis methods and as be shown, it is more transparent than the sensitivity reduction methods mentioned . In this paper we want to overcome the major drawback of QFT method which is lack of an automatic method for loop-shaping step of the method so we focus on the following problem: Given a nominal plant and QFT bounds, synthesize a controller that achieves closed-loop stability and satisfies the QFT boundaries. The usual approach to this problem involves loop-shaping in the frequency domain by manipulating the poles and zeros of the nominal loop transfer function. This process now aided by recently developed computer aided design tools proceeds by trial and error and its success often depends heavily on the experience of the loop-shaper. Thus for the novice and First time QFT user, there is a genuine need for an automatic loop-shaping tool to generate a first-cut solution. Clearly such an automatic process must involve some sort of optimization, and while recent results on convex optimization have found fruitful applications in other areas of control theory we have tried to use LMI theory for automating the loop-shaping step of QFT design.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.928-933
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• 2004

A new approach for modelling and simulation of the cutting forces in end milling processes is presented. In this approach, the cutting forces in end milling are modelled based on a predictive machining theory, in which the machining characteristic factors are predicted from input data of fundamental workpiece material properties, tool geometry and cutting conditions. In the model, each tooth of a end milling cutter is divided into a number of slices along the cutter axis. The cutting action of each of the slices is modelled as an oblique cutting process. For the first slice of each tooth, it is modelled as oblique cutting with end cutting edge effect, whereas the cutting actions of other slices are modelled as oblique cutting without end cutting edge effect. The cutting forces in the oblique cutting processes are predicted using a predictive machining theory. The total cutting forces acting on the cutter is obtained as the sum of the forces at all the cutting slices of all the teeth. A Windows-based simulation system for the cutting forces in end milling is developed using the model. Experimental milling tests have been conducted to verify the simulation system.