• Steel and Composite Structures
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• v.35 no.1
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• pp.129-145
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• 2020

In typical, structural topology optimization plays a significant role to both increase stiffness and save mass of structures in the resulting design. This study contributes to a new numerical approach of topologically optimal design of Mindlin-Reissner plates considering Winkler foundation and mathematical formulations of multi-directional variable thickness of the plate by using multi-materials. While achieving optimal multi-material topologies of the plate with multi-directional variable thickness, the weight information of structures in terms of effective utilization of the material at the appropriate thickness location may be provided for engineers and designers of structures. Besides, numerical techniques of the well-established mixed interpolation of tensorial components 4 element (MITC4) is utilized to overcome a well-known shear locking problem occurring to thin plate models. The well-founded mathematical formulation of topology optimization problem with variable thickness Mindlin-Reissner plate structures by using multiple materials is derived in detail as one of main achievements of this article. Numerical examples verify that variable thickness Mindlin-Reissner plates on Winkler foundation have a significant effect on topologically optimal multi-material design results.

• The Mathematical Education
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• v.57 no.3
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• pp.271-287
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• 2018

This is a case study that defined collaborative utterances and analyzed how they appear in the problem-solving process when 5th-grade students solved problems in groups. As a result, collaborative utterances consist of an interchange type and a deliver type and the interchange type is comprised of two process: the verification process and the modification process. Also, in groups where interchange type collaborative utterances were generated actively and students could reach an agreement easily, students applied the teacher's help to their problem-solving process right after it was provided and could solve problems even though they had some mathematics errors. In interchange-type collaborative utterances, each student's participation varies with their individual achievement. In deliver-type collaborative utterances, students who solved problems by themselves participated dominantly. The conclusions of this paper are as follows. First, interchange-type collaborative utterances fostered students' active participation and accelerated students' arguments. Second, interchange-type collaborative utterances positively influenced the problem-solving process and it is necessary to provide problems that consider students' achievement in each group. Third, groups should be comprised of students whose individual achievements are similar because students' participation in collaborative utterances varies with their achievement.

• Research in Mathematical Education
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• v.16 no.3
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• pp.195-206
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• 2012

We adopt a spirit of Problem based learning to the class of Multivariable Calculus in a school of scientifically talented students and observed effects of our teaching-learning method in the Spring Semester of 2010. Twelve students who enrolled in this class participated in this research. We have proceeded with classroom experiment for the half of semester after midterm exam so that the students could compare our teaching-learning method with usual traditional one in the subject of multivariable calculus. Especially, we investigated changes in the learning attitude and cognitive development of the students toward definition and theorem of mathematics. Each group of 4 students worked on a sheet of our well-designed structured problems of several steps in each class and presented how they understood the way of constructing new definition and related theorems. Instructor's role in this research was to guide students' activities as questioner so that students could attain the clear meanings of definitions and theorems by themselves. We firstly analyzed students' process of mathematization of definition through observing their discussions and presentations as well as their achievements in the quizzes and final exams. Secondly, we analyzed students' class-diaries collected at the end of each class in addition to pre/post surveys.

• Communications of Mathematical Education
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• v.31 no.1
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• pp.1-15
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• 2017

The university entrance examination in deeply related to high school education, adaptation and study ability in university. In this point of view, we investigate the scholastic achievement to the Calculus 1,2, linear algebra and differential equation from academic year 2006 to 2016. The above four subjects contain elementary and essential contents to study for science and engineering major in university. We compare and analyse the data of scholastic achievement and system of various university entrance examination, and we discuss and propose the methods of improvements for adaptation to each major field and study ability.

• The Mathematical Education
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• v.44 no.4 s.111
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• pp.497-508
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• 2005

The investigation of the curriculum in other countries provides meaningful implications to reflect our own curriculum. Since Korea is now under the curriculum revision, international comparative research was conducted with the curricula of Singapore and India to elicit some implications. These two countries were especially chosen because their curricula have not been actively investigated yet. Singapore mathematics curriculum starts the tracking based on students' mathematical ability from the 4th grade, and provides different curricula for the three tracks. This differentiated curriculum provides rich implications to next Korean curriculum which aims to classify the contents based on students' mathematical achievements. Indians, who have contributed significantly in the history of mathematics, have unique mathematics curriculum, remote from so called 'canonical curriculum'. After the U.S. announced the Curriculum and Evaluation Standard for School Mathematics in 1989 and the Principles and Standards for School Mathematics in 2000, many countries benchmarked these NCTM documents, and Korea was no exception. Since each country has their own school system, educational environment, and national mentality, it is not desirable to just adopt the curriculum of other countries. In this regard, Indians who have preserved their own mathematics curriculum can be a model. In sum, when we revise the curriculum, it is required to keep the balance between the open-mindedness to accept the strengths of other curricula, and the conservative attitude to preserve our own characteristics of the curriculum.

• Journal of Elementary Mathematics Education in Korea
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• v.11 no.1
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• pp.23-42
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• 2007

Learners who have taken learner-centered instruction is expected to construct conceptually mathematical knowledge which is. If so, they can have some ability to solve problems they are confronted with in the first time. To know this, First graders who have been in learner-centered instruction during 1 school year was given 7+52+186 which usually appears in the national curriculum for 3rd grade. According to the results, most of them have constructed the logic necessary to solve the given problem to them, and actually solve it. From this, it can be concluded that first, even though learners are 1st graders they can construct mathematical knowledge abstractly, second, they can apply it to the new problem, and third consequently they can got a good score in a achievement test.

• Journal for History of Mathematics
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• v.21 no.2
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• pp.39-54
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• 2008

This paper investigate Descartes' , which is significant in the history of mathematics, from standpoint of problem-solving. Descartes has clarified the general principle of problem-solving. What is more important, he has found his own new method to solve confronting problem. It is said that those great achievements have exercised profound influence over following generation. Accordingly this article analyze Descartes' work focusing his method.

• Journal of Educational Research in Mathematics
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• v.8 no.1
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• pp.73-87
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• 1998

Recently experimental class model is growingly recommended for mathematics instruction. Freudenthal(1973) points out the difficulties of learning probability and Fischebien suggested to teach probability more intuitively through games. However detailed explanations for such classes are not easy to find. This paper is to give more detailed materials for those lessons and to check its effectiveness. We give 6 topics of probability and statistics being taught in our middle school, such as histogram, concept of probability, probability calculations, expectations, standard deviations, and correlations and each of which is given along with the experimental materials to be used. We perform a trial of the methods and found some encouragement in the students' mathematical attitudes and interests but not in the achievements. We belive that the drawback of the achievement result is due to the short length of time of our experiments.

• Korean Journal of Mathematics
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• v.18 no.4
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• pp.409-424
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• 2010

We observed the symptoms that occur to students who dislike mathematics when they study mathematics and the data that mathematics is related to foreign language. This study investigated the relation between mathematics and foreign language. Continuous immersion aids not only in acquiring language but also in learning mathematics. For continuous immersion, it is essential to organize small class. We organized small class and compared large class with small class about how the relation between mathematics and language appears in achievement, rate of presence, rate of submission of report, and attitude and enthusiasm. Based on the result, we try to find out the way to increase understanding mathematics and level up the achievements.

• Journal for History of Mathematics
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• v.32 no.6
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• pp.271-279
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• 2019

Pierre-Simon de Laplace(1749-1827) is considered one of the most influential scientists in history. He was known to his contemporaries as the Newton of France, and a scientific sage valued for his magisterial syntheses of scientific works through the 18th century. Laplace was a determined mathematician, astronomer, writer, philosopher, and educator. In this paper, we take a survey of his achievements in the areas of astronomy and mathematical statistics, along with his scientific philosophy, the universal determinism.