• 대한토목학회논문집
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• 제13권5호
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• pp.235-244
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• 1993

본 연구에서는 토체내에 발생하는 파괴면(破壞面)의 방향(方向)은 선형변형율증분(線形變形率增分)이 0인 영팽창선(零膨脹線)의 방향(方向)과 일치한다고 하는 Roscoe의 영팽창선이론(零膨脹線理論)과 Mononobe-Okabe의 동적(動的) 토압이론(土壓理論)을 응용(應用)하여 지진(地震)의 영향(影響)을 고려한 동적토압이론식(動的土壓理論式)을 제안하였다. 동적토압식을 유도함에 있어서 벽체는 연직이고 재하중(載荷重)이 없으며, 뒷채움면은 수평면이고 그 재료는 조밀한 비점착성(非粘着性) 사질토(砂質土)로서 지진시에도 토질정수(土質定數)는 변화되지 않는 것으로 가정하였으며, 지진에 의한 영향을 고려하기 위하여 수평방향진도(水平方向震度)만을 고려하였다. 한편, 제안된 토압식에 포함되어 있는 수평진도(水平震度), 흙의 내부마찰각(內部摩擦角), 벽마찰각(壁摩擦角) 및 다이레이션각(角)의 영향을 분석하였으며, 유도된 이론식을 Mononobe-Okabe의 토압식과 비교분석하였다.

• 한국수학교육학회지시리즈A:수학교육
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• 제18권1호
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• pp.21-23
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• 1980

In [3], an extension of B. Brosowski s T-invariant Point Theorem is given where the linearity of the function and the convexity of the set are relaxed. In this paper, our main purpose is to generalize S. P. Singh's T-invariant Point Theorem to Approximation Theory.

• 한국수학사학회:학술대회논문집
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• 한국수학사학회 1999년도 가을학술발표회 논문초록집
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• pp.7-7
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• 1999

• 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.

• 한국지능시스템학회논문지
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• 제1권2호
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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.

• Smart Structures and Systems
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• 제13권1호
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• pp.55-80
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• 2014

The present work pays emphasis on investigating the effect of different types of debonding on the bending behaviour of active sandwich beam, consisting of both extension and shear actuators. An active sandwich beam finite element is formulated by using Timoshenko's beam theory, characterized by first order shear deformation for the core and Euler-Bernoulli's beam theory for the top and bottom faces. The problem of debondings of extension actuator and face are dealt with by employing four-region model for inner debonding and three-region model for the edge debonding respectively. Displacement based continuity conditions are enforced at the interfaces of different regions using penalty method. Firstly, piezoelectric actuation of healthy sandwich beam is assessed through deflection analysis. Then the effect of actuators' debondings with different boundary conditions on bending behavior is computationally evaluated and experimentally clamped-free case is validated. The results generated will be useful to address the damage tolerant design procedures for smart sandwich beam structures with structural control and health monitoring applications.

• 대한수학회논문집
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• 제39권2호
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• pp.373-397
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• 2024

Lambek introduced the concept of symmetric rings to expand the commutative ideal theory to noncommutative rings. In this study, we propose an extension of symmetric rings called strongly α-symmetric rings, which serves as both a generalization of strongly symmetric rings and an extension of symmetric rings. We define a ring R as strongly α-symmetric if the skew polynomial ring R[x; α] is symmetric. Consequently, we provide proofs for previously established outcomes regarding symmetric and strongly symmetric rings, directly derived from the results we have obtained. Furthermore, we explore various properties and extensions of strongly α-symmetric rings.

• 농촌지도와개발
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• 제5권1호
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• pp.45-59
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• 1998

Regional agricultural research has been activated since the mid of 1980s by the government`s integrated rural development policy based on regional unit(kun). It is called upon to meet the challenges which the agriculture confronts in the general evolution of the society. However, regretfully it seems this new approach has not succeeded in developing its own theoretical tools for the diagnostic analysis of regional agriculture. So, this study would introduce the french agrarian system theory which has been developed by the interdisciplinary research groups of the France`s National Agricultural Research Institute, which is now filtering outside the country to various parts of the world. It attempts also to apply the above theory to analyse one of agricultural regions located in the province Cheollabukdo, so as to see its theoretical pertinency and efficiency in the regional agricultural development planning which constitute the main part of the regional planning.

• 대한수학회논문집
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• 제10권1호
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• pp.49-55
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• 1995

This paper is the third of a series in which smoothness properties of function in several variables are discussed. The germ of the whole theory was laid in the works by Folland and Stein [4]. On nilpotent Lie groups, they difined analogues of the classical $L^p$ Sobolev or potential spaces in terms of fractional powers of sub-Laplacian, L and extended several basic theorems from the Euclidean theory of differentaiability to these spaces: interpolation properties, boundedness of singular integrals,..., and imbeding theorems. In this paper we study the analogue to the extension theorem for the Folland-Stein spaces. The analogue to Stein's restriction theorem were studied by M. Mekias [5] and Y.M. Kim [6]. First, we have the space of Bessel potentials on the Heisenberg group introduced by Folland [4].

• Structural Engineering and Mechanics
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• 제13권3호
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• pp.299-312
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• 2002

In this paper, a new method to solve the dynamic response problem for structures with interval parameters is presented. It is difficult to obtain all possible solutions with sharp bounds even an optimum scheme is adopted when there are many interval structural parameters. With the interval algorithm, the expressions of the interval stiffness matrix, damping matrix and mass matrices are developed. Based on the matrix perturbation theory and interval extension of function, the upper and lower bounds of dynamic response are obtained, while the sharp bounds are guaranteed by the interval operations. A numerical example, dynamic response analysis of a box cantilever beam, is given to illustrate the validity of the present method.