• Steel and Composite Structures
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• 제35권1호
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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.

• 한국수학교육학회지시리즈A:수학교육
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• 제57권3호
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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.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제16권3호
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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.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제31권1호
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• pp.1-15
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• 2017

대학 입학 제도는 고등학교 교육뿐만 아니라 입학 후 전공에의 적응 및 수학능력과도 밀접한 관련이 있다고 볼 수 있다. 이와 같은 관점에서 본 논문에서는 경희대학교 국제캠퍼스 이공계열 신입생들의 주요 과목으로 공동관리 되고 있는 미분적분학1을 2006학년도부터 2016학년도까지, 선형대수학을 2011학년도부터 2016학년도까지, 그리고 미분적분학2와 미분방정식과목에 대한 2011학년도부터 2015학년도까지의 학업성취도 및 입학전형을 비교, 분석하고 이공계열 신입생들의 전공에의 적응과 학업능력신장을 위한 개선점을 제안한다.

• 한국수학교육학회지시리즈A:수학교육
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• 제44권4호
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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.

• 한국초등수학교육학회지
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• 제11권1호
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• pp.23-42
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• 2007

학습자가 학습자 중심 수업을 경험했을 때, 학습자는 수학 지식을 개념적으로 이해 할 수 있을 것으로 기대된다. 또한, 개념적으로 이해를 한 학습자는 자신들이 접하지 않았던 새로운 문제도 해결할 수 있을 것으로 기대된다. 본 연구는 이를 알아보기 위해서, 학습자 중심 수학 수업을 받은 1학년 학생들이 수학 지식을 개념적으로 이해했으면 이를 바탕으로 학습하지 않은 지식도 해결할 수 있을 것이라는 가정을 검증하였다. 연구 결과에 따르면, 대부분의 어린이들은 이들에게 주어진 문제(7+52+186)을 해결하는데 필요한 논리를 구성하였다. 이런 사실로부터, 다음과 같은 결론을 내릴 수 있다. 첫 번째, 학습자가 1학년 학생이라고 하더라도, 이들은 수학지식을 추상적으로 구성할 수 있다. 두 번째, 이들은 자신들이 구성한 지식을 새로운 문제에 적용할 수 있다. 세 번째, 결과적으로 이들은 학업성취도 검사에서 좋은 결과를 낼 수 있다.

• 한국수학사학회지
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• 제21권2호
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• pp.39-54
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• 2008

이 논문에서는 문제해결의 입장에 서서 수학사에서 중요한 의미를 지닌 데카르트의 <기하학>을 고찰한다. 문제해결의 일반적 원리를 천명한 것만이 아니라 실제로 당면한 문제를 해결하기 위하여 새로운 방법을 찾아내는 것이야말로 데카르트가 문제해결에 관하여 후세에 영향을 크게 남긴 업적이라 할 수 있다. 따라서 본고에서는 그의 방법에 초점을 맞추어 분석하도록 한다.

• 대한수학교육학회지:수학교육학연구
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• 제8권1호
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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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• 제18권4호
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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.

• 한국수학사학회지
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• 제32권6호
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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.