• 대한수학교육학회지:학교수학
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• 제17권3호
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• pp.493-513
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• 2015

학교교육개선을 위한 방안으로서 융복합교육에 대한 사회적 관심이 증가하는 가운데 본 연구에서는 2009 개정 수학과 교육과정에 따른 중학교 1학년 수학교과서 13종에 수록된 실세계 기반의 과제 880개를 대상으로 융복합 맥락 차원 및 융복합 방식 차원과 관련하여 과제 구성상의 특징을 분석하였다. 분석 결과, 융복합교육의 맥락 차원에서는 개인적 맥락이 가장 많이 나타났고, 융복합 방식 차원에서는 타 교과의 제재가 수학 문제해결과 직접적인 관련이 없거나 단순하게 설명문 형식으로 제시되어 있는 순차모형의 과제가 가장 높은 비율로 나타났다. 이와 같은 분석결과는 수학교과를 통해 학습자의 융복합적인 역량을 함양하고 문 이과 통합을 통해 융합적 사고를 증진시키려는 목표를 달성하기에는 현행 교과서의 구성이 매우 제한적임을 보여주는 결과로써, 학습자가 살아갈 미래사회와 세계사회 맥락에서의 탐구가 가능한 과제 개발이 필요함을 시사한다. 이러한 맥락에서 타 교과의 지식 및 사회적인 쟁점과 수학교과를 융복합교육의 관점에서 보다 의미 충실하게 연결할 수 있는 과제 개발에 대한 시사점을 제안하였다.

• Journal of Mechanical Science and Technology
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• 제14권1호
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• pp.57-64
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• 2000

Recent advances in the field of control theory have enabled us to design active vibration control systems for various structures. In many studies, the controller used to suppress vibration has been synthesized for the given mathematical model of structure. In these cases, the designer has not been able to utilize the degree of freedom to adjust the structural parameters of the control object. To overcome this problem, so called 'Structure/Control Simultaneous Optimization Method' is used. In this context of view, this paper is concerned with the active vibration control of bridge towers, platforms and ocean vehicles etc. Simultaneous design method is used to achieve optimal system performance. Here, a general framework for the simultaneous design problem of output feedback case is introduced based on LMI (Linear Matrix Inequality). The simulation results show that the proposed design method achieves desirable control performance.

• Communications for Statistical Applications and Methods
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• 제9권3호
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• pp.619-627
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• 2002

It is unpractical for the optimal design theory based on the given model and assumption to be applied to the real-world experimentation. Particularly, when the experimenter feels it necessary to consider multiple objectives in experimentation, its modified version of optimality criteria is indeed desired. The constrained optimal design is one of many methods developed in this context. But when the number of constraints exceeds two, there always exists a problem in specifying the lower limit for the efficiencies of the constraints because the “infeasible solution” issue arises very quickly. In this paper, we developed a sequential approach to tackle this problem assuming that all the constraints can be ranked in terms of importance. This approach has been applied to the polynomial regression model.

• 대한기계학회논문집A
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• 제33권2호
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• pp.114-126
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• 2009

In this paper, a versatile multi-criteria optimization concept for fatigue life prediction is introduced. Multi-criteria decision making in engineering design refers to obtaining a preferred optimal solution in the context of conflicting design objectives. Compromise decision support problems are used to model engineering decisions involving multiple trade-offs. These methods typically rely on a summation of weighted attributes to accomplish trade-offs among competing objectives. This paper gives an interpretation of the decision parameters as governing both the relative importance of the attributes and the degree of compensation between them. The approach utilizes a response surface model, the compromise decision support problem, which is a multi-objective formulation based on goal programming. Examples illustrate the concepts and demonstrate their applicability.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제11권2호
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• pp.127-141
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• 2007

This paper compares and analyzes mathematics teachers' understanding of students' mathematical comprehension after experiences with the Cognitively Guided Instruction (CGI) or the Development of Mathematical Ideas (DMI) teaching strategies. This report sheds light on current issues confronted by the educational system in the context of mathematics teaching and learning. In particular, the declining rate of mathematical literacy among adolescents is discussed. Moreover, examples of CGI and DMI teaching strategies are presented to focus on the impact of these teaching styles on student-centered instruction, teachers' belief, and students' mathematical achievement, conceptual understanding and word problem solving skills. Hence, with a gradual enhancement of reformed ways of teaching mathematics in schools and the reported increase in student achievement as a result of professional development with new teaching strategies, teacher professional development programs that emphasize teachers' understanding of students' mathematical comprehension is needed rather than the currently dominant traditional pedagogy of direct instruction with a focus on teaching problem solving strategies.

• Communications for Statistical Applications and Methods
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• 제15권1호
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• pp.117-124
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• 2008

The liquidity risk is defined as an additional risk in the market due to the timing and size of a trade. A recent work by Cetin et ai. (2003) proposes a rigorous mathematical model incorporating this liquidity risk into the arbitrage pricing theory. A practical problem arising in a real market application is an estimation problem of a liquidity cost. In this paper, we propose to estimate the liquidity cost function in the context of Cetin et al. (2003) using the constrained least square (LS) method, and illustrate it by analyzing the Kellogg company data.

• 응용통계연구
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• 제13권1호
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• pp.189-196
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• 2000

포아송 분포에서 일반적으로 공액 사전 분포를 이용하여 사후확률의 수학적 계산이 간편하도록 한다. 그러나 모수 집합의 제한적 조건 때문에 비공액 사전 분포를 이용할 수 도 있다. 비공액 사전분포의 사용은 사후분포의 형태가 일상적인 분포집합의 형태를 갖지 않으므로 모형의 가정에 따라서 복잡한 구조를 갖을 수 도 있다. 특히 포아송-로그정규분포 모형에서의 모수 추정문제를 몬테 칼로방법을 이용하여 추정하고자 할 때 필요한 완전한 조건부 분포의 형태는 잘 알려진 분포의 형태를 갖지 않는다. 본 논문에서는 계층적 구조를 갖는 포아송-로그정규분포 모형에 대하여 고찰하고 추정에 있어서 잠재적 변수를 활용하여 필요한 난수발생이 쉽도록 하는 방법에 대하여 알아보았다.

• Smart Structures and Systems
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• 제11권1호
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• pp.103-122
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• 2013

It is essential to update the model with reflecting observation or inspection data for reliability estimation of existing structures. Authors proposed updated reliability analysis by using Particle Filter. We discuss how to apply the proposed method through numerical examples on reinforced concrete structures after verification of the method with hypothetical linear Gaussian problem. Reinforced concrete structures in a marine environment deteriorate with time due to chloride-induced corrosion of reinforcing bars. In the case of existing structures, it is essential to monitor the current condition such as chloride-induced corrosion and to reflect it to rational maintenance with consideration of the uncertainty. In this context, updated reliability estimation of a structure provides useful information for the rational decision. Accuracy estimation is also one of the important issues when Monte Carlo approach such as Particle Filter is adopted. Especially Particle Filter approach has a problem known as degeneracy. Effective sample size is introduced to predict the covariance of variance of limit state exceeding probabilities calculated by Particle Filter. Its validity is shown by the numerical experiments.

• International Journal of Contents
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• 제10권3호
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• pp.55-63
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• 2014

Existing science education that excludes narrative thinking impedes the understanding of the context of workbook content. The object of this research is to develop a storytelling-learning program based on narrative thinking to elevate learners' interest in science and expand their inventive problem-solving abilities. Following an analysis of the current Korean curriculum, eight types of storytelling materials that utilize local content were developed for grades 7-9. The learning program used quest storytelling and was designed such that learning activities such as investigation, discussion, and experimentation were included in the process of solving each quest. Learners experienced an interest in storytelling learning resulting from participation in this storytelling-learning program. Moreover, learners demonstrated inventive problem-solving abilities in the process of completing the stories. During the process of assembling the storytelling materials, the students interacted with enthusiasm and generated ideas. The teachers indicated a positive feedback to the storytelling program as a new attempt to stimulate learners' interests. In the future, with continuous development and application, storytelling-science-learning programs that base science learning on narrative thinking are expected to be successful.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2528-2530
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• 2004

Neural network minimization problems are often conditioned and in this contribution way to handle this will be discussed. It is shown that a better conditioned minimization problem can be obtained if the problem is separated with respect to the linear parameters. This will increase the convergence speed of the minimization. One of the most powerful uses of neural networks is in function approximation(curve fitting)[1]. A main characteristic of this solution is that function (f) to be approximated is given not explicitly but implicitly through a set of input-output pairs, named as training set, that can be easily obtained from calibration data of the measurement system. In this context, the usage of Neural Network(NN) techniques for modeling the systems behavior can provide lower interpolation errors when compared with classical methods like polynomial interpolation. This paper solve of single-variable minimization using neural network.