• 대한수학회지
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• 제32권3호
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• pp.563-571
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• 1995

The recent work of Hopkins, Kuhn and Ravenel [H-K-R] indicates the Morava K-theory, $K(n)^*(-)$, occupy an important and fundamental place in homology theory. In particular $K(n)^*(BG)$ for classifying spaces of finite groups are studied by many authors [H-K-R], [R], [T-Y 1, 2] and [Hu].

• 대한수학회논문집
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• 제11권3호
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• pp.585-593
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• 1996

We make the definition of hermitian K-theory for nonunital rings which makes as many senses as possible. We next show that the excision property in rational hermitian K-theory implies the nullity of rational $H B^-$-homology which is the antisymmetric part of Bar homology.

• 대한수학회논문집
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• 제24권2호
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• pp.247-263
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• 2009

In this paper we use degree and index theory to present new applicable fixed point theory for permissible maps.

• Structural Engineering and Mechanics
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• 제39권4호
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• pp.449-463
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• 2011

A free vibration analysis is made of a moderately-thick toroidal shell based on a shear deformation (Timoshenko-Mindlin) shell theory. This work represents an extension of earlier work by the authors which was based on a thin (Kirchoff-Love) shell theory. The analysis uses a modal approach in the circumferential direction, and numerical results are found using the differential quadrature method (DQM). The analysis is first developed for a shell of revolution of arbitrary meridian, and then specialized to a complete circular toroidal shell. A second analysis, based on the three-dimensional theory of elasticity, is presented to cover thick shells. The shear deformation theory is validated by comparing calculated results with previously published results for fifteen cases, found using thin shell theory, moderately-thick shell theory, and the theory of elasticity. Consistent agreement is observed in the comparison of different results. New frequency results are then given for moderately-thick and thick toroidal shells, considered to be completely free. The results indicate the usefulness of the shear deformation theory in determining natural frequencies for toroidal shells.

• 한국정밀공학회지
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• 제19권8호
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• pp.84-91
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• 2002

This paper analyzes the subsurface stress at the spherical contact using Hamilton equation, and with that data, calculates the fatigue limit under the variations of friction coefficient using fatigue theory. After rough surface being made, this paper figures out the random load generated by contacting to the rough surface, analyzes the stress of its subsurface, and calculates the fatigue limit of the rough surface using fatigue theory. The three parts of the fatigue theory are applied, which are critical plane theory, stress invariant theory and mesoscopic theory.

• Steel and Composite Structures
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• 제20권2호
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• pp.295-316
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• 2016

This paper presents the results of experimental investigation, numerical calculation and theoretical analysis on axial compression ratio limit values for steel reinforced concrete (SRC) special shaped columns. 17 specimens were firstly intensively carried out to investigate the hysteretic behavior of SRC special shaped columns subjected to a constant axial load and cyclic reversed loads. Two theories were used to calculate the limits of axial compression ratio for all the specimens, including the balanced failure theory and superposition theory. It was found that the results of balanced failure theory by numerical integration method cannot conform the reality of test results, while the calculation results by employing the superposition theory can agree well with the test results. On the basis of superposition theory, the design limit values of axial compression ratio under different seismic grades were proposed for SRC special shaped columns.

• Steel and Composite Structures
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• 제18권2호
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• pp.409-423
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• 2015

In the present work, a simple and refined trigonometric higher-order beam theory is developed for bending and vibration of functionally graded beams. The beauty of this theory is that, in addition to modeling the displacement field with only 3 unknowns as in Timoshenko beam theory, the thickness stretching effect (${\varepsilon}_Z{\neq}0$) is also included in the present theory. Thus, the present refined beam theory has fewer number of unknowns and equations of motion than the other shear and normal deformations theories, and it considers also the transverse shear deformation effects without requiring shear correction factors. The neutral surface position for such beams in which the material properties vary in the thickness direction is determined. Based on the present refined trigonometric higher-order beam theory and the neutral surface concept, the equations of motion are derived from Hamilton's principle. Numerical results of the present theory are compared with other theories to show the effect of the inclusion of transverse normal strain on the deflections and stresses.

• Journal of Information Science Theory and Practice
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• 제3권3호
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• pp.64-74
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• 2015

Despite the number of developed theories, it still remains a difficult task for some established and emerging scholars in various academic fields to clearly articulate new theories from research studies. This paper reviews and collates the views of scholars on what a theory is and how a good theory can be developed. It explains the concept of a theory, and the different components that make up a theory. The paper discusses the different processes of theory development by emphasizing what theory is and what theory is not. This review found that scholars differ in their definition of a theory, which leads to using terms such as model, paradigm, framework, and theory interchangeably. It found the lack of theoretical constructs in a study to be one of the factors which explains why articles are rejected for publication. This paper may be of benefit to established researchers who may be struggling with theory development, and especially younger academics who are the future of scholarship in various academic fields, particularly in information science.

• 한국환경과학회지
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• 제11권9호
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• pp.857-863
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• 2002

The meteorological elements were measured to investigate cause of summertime ice formation at Unchiri, Gangwon Province. The cause of freezing at valley was conformed as adiabatic expansion theory, latent heat of evaporation, natural convective theory, cold air remain theory, and convective freezing theory according to former study. However nither theory produced a satisfactory explanation. This studying area is not valley but ridge, and underground water surface exists at below than freezing height. wintertime temperature drop and summertime cold air spouting were explain as natural convective theory, generation of water drop on the rock was explained as cooling theory by air expansion, and ice formation on the rock was explained as adiabatic expansion theory. In conclusion, formation of ice valley at Unchiri was formed by natural convective theory, adiabatic expansion theory, and latent heat of evaporation successively.

• 수산경영론집
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• 제45권1호
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• pp.1-16
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• 2014

The study attempts to show that the theory of critical environmental variation quantum(CEVQ) has a sound logical basis and empirical support. It is well known that the theory of critical environmental variation quantum is derived from the theory of biological probability distibution function and the central limit theorem(CLT) in statistics. The study uses the case study of fisheries damages compensation caused br the public marine construction undertaken in the area do Anjeong Bay in the city of Tongyeong for empirical test of theory of CEVQ. The results shows that the CEVQ theory perfoms a good job in measuring quantatively fjsheries damages caused by outflow of cold water due to the operation of LNG company since 2002. Therefore the study proves that the CEVQ theory is a good theory having internal consistency and empirical applicability.