• Journal of Digital Convergence
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• v.12 no.6
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• pp.223-229
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• 2014

In an attempt to retrieve useful information for an efficient decision in the large knowledge system, it is generally necessary and important for a refined feature selection. Rough set has difficulty in generating optimal reducts and classifying boundary objects. In this paper, we propose quick reduction algorithm generating optimal features by rough entropy analysis for condition and decision attributes to improve these restrictions. We define a new conditional information entropy for efficient feature extraction and describe procedure of feature selection to classify the significance of features. Through the simulation of 5 datasets from UCI storage, we compare our feature selection approach based on rough set theory with the other selection theories. As the result, our modeling method is more efficient than the previous theories in classification accuracy for feature selection.

• Korean Journal of Food Science and Technology
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• v.27 no.2
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• pp.164-169
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• 1995

Fictitious experiment to control extrusion process was carried out using the fuzzy theory. Algorithm of the fuzzy logic controller(FLC) was made based on the general principles of extrusion. In the simulation, at first, thickness of extrudate was measured as feedback input variable. Secondly, a set point of screw speed was determined as output variable of extruder operating condition through FLC. Finally, the thickness of extrudate was controlled as a given set point. Barrel heater was simply controlled as on/off state, which was not fuzzy controlled.

• KIEE International Transactions on Power Engineering
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• v.2A no.3
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• pp.121-128
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• 2002

This study proposes a new method for transmission system expansion planning using fuzzy integer programming. It presents stepwise cost characteristics analysis which is a practical condition of an actual system. A branch and bound method which includes the network flow method and the maximum flow - minimum cut set theorem has been used in order to carry out the stepwise cost characteristics analysis. Uncertainties of the permissibility of the construction cost and the lenient reserve rate and load forecasting of expansion planning have been included and also processed using the fuzzy set theory in this study. In order to carry out the latter analysis, the solving procedure is illustrated in detail by the branch and bound method which includes the network flow method and maximum flow-minimum cut set theorem. Finally, case studies on the 21- bus test system show that the algorithm proposed is efficiently applicable to the practical expansion planning of transmission systems in the future.

• Asia pacific journal of information systems
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• v.32 no.2
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• pp.249-274
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• 2022

This study is to focuses on users' attitudes toward augmented reality games. Based on the Technology Acceptance Model (TAM) and Flow theory, continuous usage intention was set as a dependent variable, and immersion was set as a mediating variable. As independent variables, spatial presence, perceived interactivity, perceived pleasure, and sickness were set. Besides, this study strived to compare and analyze Korean and Chinese Data. The results of this study were as follows. First of all, Korean users significantly affected spatial presence, perceived pleasure, and immersion. Spatial presence and perceived pleasure had also mediated effects on continuous usage intention through immersion. However, perceived interactivity and sickness did not affect immersion and even no mediating effect to continuous usage intention. In the case of Chinese users, spatial presence, perceived interactivity, and perceived pleasure were grouped into one variable. This variable influenced immersion and also had mediated effect on continuous usage intention. However, sickness, like Korean users, did not affect the set path. This study had implications for analyzing user perspective using immersion, a significant variable in previous research. In addition, this study found similarities and characteristics through a comparative analysis between Korean and Chinese users indirectly.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.231-234
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• 1990

This paper shows real-time control technique of voltage-reactive power using the fuzzy theory. Here, major benefits of applying the fuzzy set theory as follow. First, heuristic knowledge of operator has been used in the operation and control of power system. Second, difficulties in traditional multi-objective numerical solution methods have been solved. Also, to achieve optimizing process on the voltage-reactive power control conventional search method have been used.

• Bulletin of the Korean Mathematical Society
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• v.34 no.2
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• pp.199-204
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• 1997

To develope the theory of BCI-algebras, the idel theory plays an important role. The first author [4] introduced the notion of T-ideal in BCI-algebras. In this paper, we first construct a special set, called T-part, in a BCI-algebra X. We show that the T-part of X is a subalgebra of X. We give equivalent conditions that the T-part of X is an ideal. By using T-part, we provide an equivalent condition that every ideal is a T-ideal.

• Journal of the Korean Mathematical Society
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• v.37 no.1
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• pp.55-72
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• 2000

In this paper, we develop the Grobner-Shirshov basis theory for the representations of associative algebras by introducing the notion of Grobner-Shirshov pairs. Our result can be applied to solve the reduction problem in representation theory and to construct monomial bases of representations of associative algebras. As an illustration, we give an explicit construction of Grobner-Shirshov pairs and monomial bases for finite dimensional irreducible representations of the simple tie algebra sl$_3$. Each of these monomial bases is in 1-1 correspondence with the set of semistandard Young tableaux with a given shape.

• East Asian mathematical journal
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• v.24 no.1
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• pp.11-20
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• 2008

We survey recent results and some conjectures in analytical fixed point theory. We list the known fixed point theorems for Kakutani maps, Fan-Browder maps, locally selectionable maps, approximable maps, admissible maps, and the better admissible class $\cal{B}$ of maps. We also give 16 conjectures related to that theory.

• Journal of the Korean Mathematical Society
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• v.34 no.1
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• pp.1-12
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• 1997

Complementaity problem theory developed by Lemke [10], Cottle and Dantzig [8] and others in the early 1960s and thereafter, has numerous applications in diverse fields of mathematical and engineering sciences. And it is closely related to variational inquality theory and fixed point theory. Recently, fixed point methods for the solving of nonlinear complementarity problems were considered by Noor et al. [11, 12]. Also complementarity problems related to variational inequality problems were investigated by Chang [1], Cottle [7] and others.

• Bulletin of the Korean Chemical Society
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• v.19 no.5
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• pp.553-557
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• 1998

Density functional theory calculations are reported for the carbon clusters bonded with two oxygen atoms $OC_No$ (n=2-6). The structures, vibrational frequencies and dipole moments are computed by BLYP theory with the 6-311G* basis set. Good agreement is obtained between the computed and experimentally observed properties. The ground states of these molecules are shown to be linear. Cyclic structures with higher energy are also predicted.