• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.5
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• pp.70-75
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• 2008

This paper describes a tool-clamping/unclamping mechanism for application of a micro-spindle. The mechanism is based on one-way shape memory effect and interference-fit. The corresponding mathematical models and a few considerable design parameters are mentioned in this paper. Especially, necessary conditions for the clamping and unclamping operation are investigated through finite element analysis. The analysis results show that the differences between the diametral deformations of the tool holder in high temperature and that in low temperature are increased according to amounts of the interference. Thus the less interference between the tool-holder and the ring, the less tolerance to allow the clamping and unclamping operation because the inner diameter of the tool holder in high temperature should be smaller than the diameter of the tool shank, and that in low temperature should be larger than the diameter of the tool shank. In addition, the design for maximization of clamping force are investigated based on finite element analysis. The results show that the more amounts of the interference, the more clamping force. As the result, the interference should be considered as a important factor to maximize the tool clamping force.

• Research in Mathematical Education
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• v.27 no.1
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• pp.25-47
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• 2024

Mathematical modeling activities are gaining popularity in K-12 mathematics education curricula worldwide. These activities serve dual purposes by aiding students in making sense of real-world situations intertwined with social justice while acquiring mathematical knowledge. Despite efforts to prepare teacher candidates for instructing in mathematical modeling within a single country, little attention has been given to teacher candidates' approaches to mathematical modeling on a social justice issue from different countries. This article employs an in-depth, small-scale comparative study to examine the approaches of U.S. and Korean teacher candidates in solving a justice-oriented mathematics task. Our findings reveal that, although both U.S. and Korean teacher candidates identified certain variables as key when constructing a mathematical model, Korean teacher candidates formulated a more nuanced model than U.S. candidates by considering diverse variables. However, U.S. teacher candidates exhibited a heightened engagement in linking the task to social justice issues, whereas Korean teacher candidates barely perceived real-world problems in relation to social justice concerns. This study serves as a valuable tool to inform the roles and limitations of teacher education programs, shaped within specific educational contexts.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.781-784
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• 2005

The feed drive inclination significantly influences product quality, machine tool accuracy and life time. However, the accurate measurement of the inclination needs the skilled engineers and the accurate leveling instruments such as spirits or electric levels. In this study a novel methodology for the estimation of inclination angle of machine tool feed drive is proposed. The proposed methodology utilizes the motor current signals and a new mathematical model of machine tool feed drive considering inclination. The experiment results showed that the proposed method successfully estimates the inclination angle, as well as newly proposed model also enhances the accuracy of the machine tool feed drive model by introducing the inclination effects.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.3
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• pp.255-259
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• 2013

To evaluate the suitability of the Weaponeering tool for the Surface to Surface Guided Missile at the Above-Ground Buildings, we analyzed the relation among SSPD, $MAE_{bldg}$, CEP and the number of missiles, expected damage etc.. According to the analysis, if the target Length is 100m, and $\sqrt{MAE_{bldg}}$ is longer than the target length, the tool is suitable but shorter than it, the tool is not suitable. So Morris Driels's Weaponeering Tool needs new adaptive algorithm to Translate as the Target size and $MAE_{bldg}$.

• International Journal of Advanced Culture Technology
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• v.10 no.1
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• pp.265-273
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• 2022

The aim of this study is to investigate the relationship between the object ability, basic movement ability, and mathematical ability of young children. Next, through this study, the influence of young children's object manipulation ability and basic movement ability on mathematical ability was investigated. The subjects of this study were 80 children aged 5 years old. As a research tool, the non-mobile movement and mobile movement, the basic movement development test scale, and the young children's picture-mathematical ability test scale were used. This survey was conducted from October 2018 to January 2019. For data analysis, correlation analysis and hierarchical multiple regression analysis were performed using the spss program. As a result of the study, it was found that there was a significant positive correlation between the non-mobile ability, movement ability, object manipulation ability and mathematical ability of young children. It was found that young children's ability to manipulate objects and non-movement abilities had positive effect on their mathematical abilities. The movement ability of young children had both negative and positive effects on mathematical ability, but it was not found to be statistically significant. This study is meaningful in that it investigated the effects of non-mobile movement, mobile movement ability, and object manipulation ability, which are sub-capabilities of basic movement ability, which had not been investigated so far, on the mathematical ability of young children.

• The Mathematical Education
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• v.42 no.5
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• pp.647-672
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• 2003

This study sought to determine the impact of the graphing calculator on prospective math-teachers' mathematical thinking while they engaged in the exploratory tasks. To understand students' thinking processes, two groups of three students enrolled in the college of education program participated in the study and their performances were audio-taped and described in the observers' notebooks. The results indicated that the prospective teachers got the clues in recalling the prior memory, adapting the algebraic knowledge to given problems, and finding the patterns related to data, to solve the tasks based on inductive, deductive, and creative thinking. The graphing calculator amplified the speed and accuracy of problem-solving strategies and resulted partly in students' progress to the creative thinking by their concept development.

• Journal for History of Mathematics
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• v.26 no.4
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• pp.301-320
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• 2013

Although many people have recognized the importance of history of mathematics in mathematics education, there are few studies that history and mathematics educations are connected. In this paper, we present and discuss the ways of introducing the instruction with mathematics machines. This instruction use the history of mathematics as part of a class not as a tool to stimulate students' interest but as a goal that it can be targeted mathematical itself. To do this, we first analyze the characteristics of applying history of mathematics in mathematical education, second, describe the meaning and the educational value of mathematical machines, and finally explained the way of applying history of mathematics with mathematics machines. The Instruction of history of mathematics with mathematics machines has advantages that practice (manipulation and experiment) and theory (elaboration of definition, production of conjectures and constructions of proofs) are interlaced within a historic-cultural perspective.

• Korean Journal of Child Studies
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• v.35 no.6
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• pp.93-110
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• 2014

The purpose of this study was to examine the effects of cookbook making activities on young children's mathematical concept and writing development. The participants were comprised of 50 five-year-old children from two intact classes from a kindergarten in Gyeonggi province, and they were divided into an experimental and a comparison group. The experimental group participated in cooking activities and produced cookbooks as extension activities whereas the comparison group carried out only cooking activities. The results indicated that the children in the experimental group received statistically higher scores in mathematical concept- and writing-tests, suggesting that cookbook making activities are a useful educational tool for enhancing young children's mathematical concepts and facilitating their writing development.

• Communications of Mathematical Education
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• v.25 no.2
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• pp.309-321
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• 2011

In this paper, we introduce how we developed a dynamic Excel Grapher which can be used for mathematics education. Developed tools can be used in college mathematics as well as a secondary school mathematics education. It can be downloaded for your test or teaching. (http://maxtrix.skku.ac.kr/2010-ExcelGrapher/index.htm)

• Journal of Korean Institute of Industrial Engineers
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• v.20 no.2
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• pp.19-30
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• 1994

Generally, a planning problem in a flexible manufacturing system is considered to be a composite of three interdependent tasks : part selection, loading, and routing mix. This research presents a mathematical model which can concurrently solve part selection, loading, and routing mix problems, so the problems that are caused by treating the planning problems independently are solved. The mathematical model is aimed to minimize system unbalance and the number of late parts, including constraints such as machine capacity, tool magazine capacity, and tool inventory. To illustrate the application of the model, an example is included. Solution procedure based on Lagrangian relaxation is also suggested for larger-sized problems.