• 한국수학교육학회지시리즈A:수학교육
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• 제50권1호
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• pp.1-12
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• 2011

It is the aim of this paper to study the target problem solving process in reference to the base problem. We observed closely how students solve the target problem in reference to the base problem. The students couldn't solve the target problem, although they succeed to find the base problem. This comes from failing to discover the structural similarity between the target problem and the base problem. Especially it is important to cognize the proper corresponding of primary components between the base problem and target problem. And there is sometimes a part component of the target problem equivalent to the base problem and the target problem can't be solved without the insight into this fact. Consequently, finding the base problem fail to reach solving the target problem without the insight into their structural similarity. We have to make efforts to have an insight into the structural similarity between the target problem and the base problem to solve the target problem.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 봄 학술발표회 논문집
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• pp.260-267
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• 1999

In this paper, We propose the initial shape finding and dynamic analysis of cable dome structure are presented. Cable dome that is consist of three component such as cable, strut and fabric membrane have complex structural characteristics. Main structural system of cable dome is cable-strut tensegric system, and fabric membrane element Is conceived as cladding roof material. One of the important problem of cable dome is shape finding of those subjected to cable and membrane forces, which stabilize the structures. And the other is structural response from external load effect such as snow and wind When cable dome are subjected to dynamic load such as wind load each structural component has many important problem because of their special structural characteristics. One problem is that geometrical nonlinearity should be considered in the dynamic analysis because large deformation is occurred from their flexible characteristic. The other problem is that wrinkling occurs occasionally because cable and membrane elements can not transmit compressive forces. So this paper describe the physical structural response of cable dome structure.

• Structural Engineering and Mechanics
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• 제75권4호
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• pp.445-454
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• 2020

Structural damage identification (SDI) is a crucial step in structural health monitoring. However, some of the existing SDI methods cannot provide enough identification accuracy and efficiency in practice. A novel whale optimization algorithm (WOA) based method is proposed for SDI by weighting modal data and flexibility assurance criterion in this study. At first, the SDI problem is mathematically converted into a constrained optimization problem. Unlike traditional objective function defined using frequencies and mode shapes, a new objective function on the SDI problem is formulated by weighting both modal data and flexibility assurance criterion. Then, the WOA method, due to its good performance of fast convergence and global searching ability, is adopted to provide an accurate solution to the SDI problem, different predator mechanisms are formulated and their probability thresholds are selected. Finally, the performance of the proposed method is assessed by numerical simulations on a simply-supported beam and a 31-bar truss structures. For the given multiple structural damage conditions under environmental noises, the WOA-based SDI method can effectively locate structural damages and accurately estimate severities of damages. Compared with other optimization methods, such as particle swarm optimization and dragonfly algorithm, the proposed WOA-based method outperforms in accuracy and efficiency, which can provide a more effective and potential tool for the SDI problem.

• 한국초등수학교육학회지
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• 제12권2호
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• pp.101-124
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• 2008

본 연구에서는 초등학교 5학년 학생들을 대상으로 구조중심 협동학습을 적용한 문제 만들기 학습이 수학학업성취도 및 수학적 성향에 어떠한 효과가 있는지를 분석하여 초등학교 학습지도에 도움을 줄 수 있는 교수-학습 방법을 제공하기 위한 것이다. 여기서 활용한 문제 만들기 학습 유형은 송민정(2004)의 내용을 참고로 하였으며, 협동학습 구조를 수업 시에 적절히 활용함으로써 학생들에게 수학에 대한 관심과 흥미를 유발시켜서 학업성취도 및 수학적 성향에 긍정적인 영향이 있음을 알 수 있었다.

• Industrial Engineering and Management Systems
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• 제7권3호
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• pp.245-256
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• 2008

In order to cope with the ill-defined problem of human behavior being immanent uncertainty, several methodologies have been studied in game theoretic, social psychological and political science frameworks. As methods to arrange system elements systematically and draw out the consenting structural model concretively, ISM, FSM and DEMATEL based on graph theory etc. have been proposed. In this paper, we propose a modified structural modeling method to recognize the nature of problem. We introduce the statistical method to adjust the establishment levels in group decision situation. From this, it will become possible to obtain effectively and smoothly the structural model of group members in comparison with the traditional methods. Further we propose a procedure for achieving the consenting structural model of group members based on the structural modeling method. By applying the method to recognize the nature of ill-defined problems, it will be possible to solve the given problem effectively and rationally. In order to inspect the effectiveness of the method, we conduct a practical problem as an empirical study: "Behavior analysis of passengers for the Joban line of East Japan Railway Company after new railway service of Tsukuba Express opened".

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.481-488
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• 1998

The drift and inter-story drift control method for steel structures subjected to seismic forces is formulated into a structural optimization problem in this paper. The formulated optimization problem with constraints on drift, inter-story drifts, and member strengthes are transformed into an unconstrained optimization problem. For the solution of the tranformed optimization problem an searching algorithm based on the gradient projection method utilizing gradient information on eigenvalues and eigenvectors are developed and presented in detail. The performance of the proposed algorithm is demonstrated by application to drift control of a verifying example.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제25권1호
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• pp.21-45
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• 2011

본 연구는 4명의 중학교 3학년 학생들이 주어진 표적 문제를 해결하는 과정을 분석하여 학생들이 보이는 다양한 활동 요소 중 구조적 유사성의 인식, 분석적 활동 그리고 비교 활동에 주목하여 이들 활동이 표적 문제의 해결에서 어떤 역할을 하는지 살펴보았다. 4명의 학생들의 문제 해결 과정을 개별적으로 관찰하고 면담한 후, 이 과정에서 학생들이 보인 반응을 분석하여 다음과 같은 결과를 얻었다. 표적 문제의 해결에 근원 문제의 해법을 적용할 수 있는 토대를 마련하는데 도움을 주는 활동 중의 하나로 구조적 유사성의 인식이 그 역할을 수행할 수 있음을, 또 문제 해결을 위해 추측한 사실에 대한 진위 여부의 판단 근거로 분석적 활동을 활용함을 확인하였다. 그리고 표적 문제의 문제점을 인식하게 하여 표적 문제의 해결 방향을 설정하는데 도움을 제공하는 것으로 비교 활동을 활용함을 확인하였다. 따라서 현장에서 수학을 가르치는 교사는 표적 문제의 해결을 위해 유사 문제와의 구조적 유사성, 분석적 활동 그리고 비교 활동에 초점을 맞추어 문제의 해결을 지도하는 노력이 요구된다. 뿐 만 아나라 본 연구에서 언급한 세 가지 요소 이외에 더 많은 요소가 있을 수 있으며 그 요소들의 역할을 탐구하는 후속연구도 필요하다.

• 한국지진공학회논문집
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• 제15권2호
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• pp.1-9
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• 2011

불확실성을 가지는 하중의 변동성을 고려한 구조제어시스템의 최적설계방법에 관하여 연구하였다. 일반적인 제어시스템의 설계 문제가 구조물과 제어시스템간의 상호작용 고려하여 구조-제어 시스템을 최적화이나, 이 연구에서는 하중-구조물-제어 시스템간의 상호작용에 대한 최적설계방법에 관하여 다루었다. 구조물의 응답을 최대화하는 하중과, 이를 최소화하는 구조제어시스템을 동시에 구하는 최대-최소문제(Min-max Problem)를 정식화하고, 최적설계변수를 효율적으로 찾는 방법으로 병렬진화 알고리즘을 이용하여 불확실성이 존재하는 선형구조제어시스템의 최적설계방법을 제시하였다. 지진하중을 받는 구조물의 제진시스템 설계 예 및 수치해석을 통하여 연구한 방법의 타당성을 검증하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1996년도 봄 학술발표회 논문집
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• pp.182-189
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• 1996

The focus of this study is on the problem of the design of structure of undetermined topology. This problem has been regarded as being the most challenging of structural optimization problems, because of the difficulty of allowing topology to change. Conventional approaches break down when element sizes approach to zero, due to stiffness matrix singularity. In this study, a novel nonlinear Programming formulation of the topology Problem is developed and examined. Its main feature is the ability to account for topology variation through zero element sizes. Stiffness matrix singularity is avoided by embedding the equilibrium equations as equality constraints in the optimization problem. Although the formulation is general, two dimensional plane elasticity examples are presented. The design problem is to find minimum weight of a plane structure of fixed geometry but variable topology, subject to constraints on stress and displacement. Variables are thicknesses of finite elements, and are permitted to assume zero sizes. The examples demonstrate that the formulation is effective for finding at least a locally minimal weight.

• Structural Engineering and Mechanics
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• 제2권3호
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• pp.295-309
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• 1994

The present paper concerns the mathematical study and the numerical treatment of the problem of semirigid connections in bolted steel column base plates by taking into account the possibility of appearance of separation phenomena on the contact surface under certain loading conditions. In order to obtain a convenient discrete form to simulate the structural behaviour of a steel column base plate, the continuous contact problem is first formulated as a variational inequality problem or, equivalently, as a quadratic programming problem. By applying an appropriate finite element scheme, the discrete problem is formulated as a quadratic optimization problem which expresses, from the standpoint of Mechanics, the principle of minimum potential energy of the semirigid connection at the state of equilibrium. For the numerical treatment of this problem, two effective and easy-to-use solution strategies based on quadratic optimization algorithms are proposed. This technique is illustrated by means of a numerical application.