• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.38-38
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• 2009

Characteristics of the photonic bandgaps (PBGs) in two-dimensional photonic crystals (2D PCs) with a hexagonal lattice have theoretically studied using a finite difference time domain (FDTD) simulation. In this research, we propose a concept of optical coverage ratio (OCR) as a new structural parameter to determine the PBGs for E-polarized light. The OCR is an optically compensated filling factor. It is possible to normalize the PBGs of 2D PCs by introducing the OCR.

• Journal of the Korean Chemical Society
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• v.44 no.6
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• pp.587-591
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• 2000

Many theories have been suggested to obtain an equation of state for polymeric liquids. Most of them are based on the concepts of cell, hole, free volume or lattice etc. One of the most succesful theories is an equation of state theory of Flory and his coworkers based on the concept of free volume. In this work, van der Waals potential used in Flory's theory was modified, giving a new equation of state for polymeric liquids. The calculated results showed that the new equation of state gave better agreement with experimental PVT data than Flory's theory.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.1
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• pp.61-66
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• 2009

Characteristics of the photonic bandgaps (PEGs) in two-dimensional photonic crystals (2D PCs) with a square lattice have theoretically studied using a finite difference time domain (FDTD) simulation. In this paper, we propose a concept of optical coverage ratio (OCR) as a new structural parameter to determine the PEGs for E-polarized light. The OCR is an optically compensated filling factor. It is possible to normalize the PEGs of 2D PCs by introducing the OCR.

• Journal of the Korea Society of Computer and Information
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• v.14 no.6
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• pp.91-98
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• 2009

In this paper, this model ensures confidentiality and integrity of mandatory access cotrol policy which based on fuzzy function with importance of information. And it solves authorization abuse problem through role graph creation algorithm and flowing policy that security grade is applied. Because this model composes role hierarchy which bind similar role concept to apply to commercial environment, it has expansile advantage by large scale security system as well as is easy that add new role.

• Journal of the Korea Concrete Institute
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• v.22 no.1
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• pp.103-111
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• 2010

An efficient design concept for earthquake loads, which is called performance based design, has been standard design in USA, Europe and Japan since those countries experienced severe earthquake damage at end of 90's. For general design, struttie model well predicts the strength of the disturbed region, however, it does not provide ductility information at the failure. Therefore, simple tools which are able to predict both the strength and the ductility of RC structures are in demand. 2D lattice model is introduced in this study as an analysis tool for the RC structures subject to earthquake. Experimental correlation studies indicate the 2D lattice model quite well predict the strength as well as the ductility of RC structures.

• The KIPS Transactions:PartD
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• v.15D no.3
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• pp.429-440
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• 2008

Formal Concept Analysis (FCA) is a widely used methodology for data analysis, which extracts concepts and builds a concept hierarchy from given data. A concept consists of objects and attributes shared by those objects, and a concept hierarchy includes information on super-sub relations among the concepts. In this paper, we propose a method for extracting Implication and Association rules from a concept hierarchy given a query by a user. The method also describes a way for displaying the extracted rules. Based on this method, we implemented an automatic tool, QAG-Wizard. Because the QAG-Wizard not only elicits relation information for the given query, but also displays it in structured form intuitively, we expect that it can be used in the fields of data analysis, data mining and information retrieval for various purposes.

• Nuclear Engineering and Technology
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• v.18 no.3
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• pp.228-237
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• 1986

This paper provides a comparative study on methodologies for solutions of the inverse problems of certain basic fuzzy relational equations, with which fuzzy set is defined as mapping from sets into complete Brouwerian lattice. Three different algorithms developed so far are discussed and applied to fault diagnosis problem for the main coolant pump of nuclear power plants.

• Nuclear Engineering and Technology
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• v.42 no.3
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• pp.271-278
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• 2010

While the deterministic lattice physics/depletion codes use leakage-corrected critical spectrum (although approximate due to the B1 buckling search employed), Monte Carlo depletion codes currently in use do not have such a feature in spite of their heterogeneity and continuous-energy modeling capability. This paper describes an approach to Monte Carlo depletion with leakage-corrected critical spectrum derived from first principles. This is based on the concept of albedo eigenvalue treated as weight of the reflected neutron in Monte Carlo simulation.

• Journal of the Korea Furniture Society
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• v.28 no.1
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• pp.80-87
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• 2017

As modern society attaches important to a value in mental aspect and characteristics of consumers who become diverse and individualistic, lighting design also changes closely with everyday life. This study suggests a new concept of indoor lighting design, combining natural objects with lattice and Korean paper, one of our representative traditional materials in lighting design used in everyday life. In particular, it was designed with aesthetic sense of traditional culture and Korean sentiment besides external effect and function by combining Korean paper with natural objects such as insect and plant, material that could be easily obtain around us. As a result, it is intended to enhance quality of life and pursue happiness by suggesting a new concept of lighting design which is modern, harmonizes with everyday life of modern humans who become individualistic, and can arouse sensibility, overcoming the limitations of traditional lighting in indoor lighting.

• Journal of applied mathematics & informatics
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• v.39 no.3_4
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• pp.569-585
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• 2021

In this paper, we introduce the concept of relative co-fuzzy annihilator filters in distributive lattices. We give a set of equivalent conditions for a co-fuzzy annihilator to be a fuzzy filter and we characterize distributive lattices with the help of co-fuzzy annihilator filters. Furthermore, using the concept of relative co-fuzzy annihilators, we prove that the class of fuzzy filters of distributive lattices forms a Heyting algebra. We also study co-fuzzy annihilator filters. It is proved that the set of all co-fuzzy annihilator filters forms a complete Boolean algebra.