• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.2
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• pp.195-202
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• 2014

The Global Positioning System (GPS), which has various military and commercial applications, is designed to estimate the location of the specific user or object. In order to accurately estimate the location, GPS requires at least four satellite signals. The GPS receiver operates on extremely low signal-to-noise ratio (SNR) environment and it may suffer from various interference signals with the extremely high power. In this paper, we introduce a blind adaptive receiver based on the modified despreader, which suppress interference signals and detect GPS signals of interest without requiring explicit angle-of-arrival (AOA) information. We, also, provide the mathematical analysis for the signal-to-interference and noise ratio (SINR) of the modified despeader beamformer output. A representative computer simulation example is presented to illustrate the interference suppression performance of the considered GPS receiver and mathematical analysis of the SINR.

• Communications of Mathematical Education
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• v.27 no.2
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• pp.121-134
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• 2013

Linear Algebra are arguably the most popular math subjects in colleges. We believe that students' learning and understanding of linear algebra can be improved substantially if we incorporate the latest advanced information technologies in our teaching. We found that the open source mathematics program 'Sage' (http://sagemath.org) can be a good candidate to achieve our goal of improving students' interest and learning of linear algebra. In particular, we developed a simple mobile content which is available for Sage commands on common cell phones in 2009. In this paper, we introduce the mobile Sage which contains many Sage functions on a smart-phone and the mobile linear algebra content model(lecture notes, and video lectures, problem solving, and CAS tools) and it will be useful to students for self-directed learning in college mathematics education.

• Education of Primary School Mathematics
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• v.1 no.2
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• pp.85-95
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• 1997

Recently, by the popularization of computers and the development of many kinds of information transmission software, the living pattern in business offices and in home-life have changed rapidly. Because of the great progression of today's science technology, the influence of social education on the children is larger than that of the traditional school.. By a rapid change in the social atmosphere, there are some people who insist the traditional school education system is of no use any more. There have been many calls for reform of traditional schooling and in particular there has been major rethinking of school mathematics. The initial demand for change in elementary school mathematics is because of the poor achievement of students. There are even more compelling reasons for change. For example today's science technology society requires a different mathematical literacy for its citizens than that of the past. The importance of problem-solving based on interest and progress is more important than just paper-pencil computation in elementary schools. And also the increasing information wave of today's society demands that the school accept the long-distance education which could not be imagined in the past. Taking account of this variety, school education in the future should willingly introduce and apply the open education system to keep pace with today's society. To accept society demands actively, today's schools are going to accept and apply the idea of the open education. In this viewpoint, the purpose of the paper is to analyze the causes of under-achievement in mathematics teaming, the directions of school mathematics education, the system of textbooks and the problems of teaching-learning programs and paper-pencil test.

• Education of Primary School Mathematics
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• v.19 no.2
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• pp.143-160
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• 2016

Despite the recent increasing interest in classroom expertise of teachers for gifted there has been lack of research on exploring or analyzing the components of classes for gifted tailored to the characteristics of each subject matter Given this, this study looked for the components of performance domain of classes for gifted in mathematics and then analyzed one teacher's 12 lessons in terms of the components. The features of the lessons included the establishment of classroom atmosphere by considering the characteristics of mathematically gifted students, the introduction of or expansion to mathematically enriched tasks, promotion to mathematically higher thinking, and emphasis of mathematical pattern, connections, and utility. This study is expected for researchers to provide a practical case on how to analyze elementary classes for gifted in mathematics. It also helps teachers who teach gifted students to develop professional vision of mathematics instruction and to increase their classroom expertise.

• Journal of the Korean Mathematical Society
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• v.46 no.2
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• pp.363-447
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• 2009

The author previously defined the spectral invariants, denoted by $\rho(H;\;a)$, of a Hamiltonian function H as the mini-max value of the action functional ${\cal{A}}_H$ over the Novikov Floer cycles in the Floer homology class dual to the quantum cohomology class a. The spectrality axiom of the invariant $\rho(H;\;a)$ states that the mini-max value is a critical value of the action functional ${\cal{A}}_H$. The main purpose of the present paper is to prove this axiom for nondegenerate Hamiltonian functions in irrational symplectic manifolds (M, $\omega$). We also prove that the spectral invariant function ${\rho}_a$ : $H\;{\mapsto}\;\rho(H;\;a)$ can be pushed down to a continuous function defined on the universal (${\acute{e}}tale$) covering space $\widetilde{HAM}$(M, $\omega$) of the group Ham((M, $\omega$) of Hamiltonian diffeomorphisms on general (M, $\omega$). For a certain generic homotopy, which we call a Cerf homotopy ${\cal{H}}\;=\;\{H^s\}_{0{\leq}s{\leq}1}$ of Hamiltonians, the function ${\rho}_a\;{\circ}\;{\cal{H}}$ : $s\;{\mapsto}\;{\rho}(H^s;\;a)$ is piecewise smooth away from a countable subset of [0, 1] for each non-zero quantum cohomology class a. The proof of this nondegenerate spectrality relies on several new ingredients in the chain level Floer theory, which have their own independent interest: a structure theorem on the Cerf bifurcation diagram of the critical values of the action functionals associated to a generic one-parameter family of Hamiltonian functions, a general structure theorem and the handle sliding lemma of Novikov Floer cycles over such a family and a family version of new transversality statements involving the Floer chain map, and many others. We call this chain level Floer theory as a whole the Floer mini-max theory.

• Journal of Elementary Mathematics Education in Korea
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• v.13 no.1
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• pp.51-74
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• 2009

The purpose of this study is to search for various strategies that could self-regulated learning within cyber home study efficiently, to operate the cyber home study based on such strategies, to manage and support students' learning and to investigate what effects it would have on the ability of self-regulated learning and attitude. In this study, an operational strategy for cyber home study according to the compositional elements of self-regulated learning based on prior studies. Then, the study developed the learning contents of cyber home study and operated cyber home study according to the operational strategy. From the results of the analysis obtained in this study, the following conclusions can be drawn as follows. First, A learner's self-regulated learning capability is able to be improved by self-regulated leaning strategies. Cyber home study that would enable students to implement the leaning on their own through learning contents and operating strategies corresponding to them was the environment that could help their self-regulated learning. Second, in order to find out students' satisfaction for the application of cyber home study, the study compared the survey of cyber home study with the frequency and percentage by each question and the mean value of technical statistics. Cyber home study let students have positive recognition on mathematical learning, and especially as shown in the results of the interview, it was helpful to improve students' interest and confidence as well as their mathematical learning.

• Communications of Mathematical Education
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• v.25 no.4
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• pp.681-691
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• 2011

Mathematics curriculum according to 2009 Revised National Curriculum suggests that school mathematics must cultivate interest and curiosity about mathematics in addition to creative thinking ability of students, and ability and attitude of observing and analyzing many things happening around. Centroid of a triangle in 2007 Revised National Curriculum is defined as 'an intersection point of three median lines of a triangle' and it has been instructed focusing on proof study that uses characteristic of parallel lines and similarity of a triangle. This could not teach by focusing on the centroid itself and there is a problem of planting a miss concept to students. And therefore this writing suggests centroid must be taught according to its essence that centroid is 'a dot that forms equilibrium', and a justification method about this could be different.

• Communications of Mathematical Education
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• v.29 no.2
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• pp.255-279
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• 2015

Educating for character was emphasized in 2009 reformed Korea national mathematics curriculum. Thus, in this study we basically conducted to realize the character education. This study aimed to develop the teaching and learning materials for character education in middle school. For the purpose of this study, the following study was carried out. First, we investigated the concept of character education. Second, based on this, we extracted the three factor(altruism, rationality, course orientation) for character education in mathematics teaching and learning. Third, we developed five teaching and learning models for character education. The five kinds of models are 'Respect model', 'Self-directed model', 'Cooperation-centered model', 'Self-interest model, 'Story sympathy model'. Finally, We have developed a teaching and learning materials in accordance with the models. And, we applied to the classroom and confirmed its effectiveness.

• Communications of Mathematical Education
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• v.28 no.4
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• pp.475-492
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• 2014

This study aimed to explore the affective characteristics of primary and middle school students in mathematics and to analyze the relationship between the affective characteristics and initiative in mathematics learning. For the purpose of this study, a survey was conducted for students in a primary and a middle school in Incheon area. The questionnaires using in this study consisted of five affective domains of interest, self-efficacy, value, self-regulation, and mathematics anxiety. The results of this study showed that the participant students' affective characteristics tended to be decreased by grades. Moreover, the gender differences were increase as the participant students grew older. Students who take the initiative in mathematics learning showed better affective characteristics in general than students who depends on other assistants.

• Communications of Mathematical Education
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• v.23 no.2
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• pp.383-398
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• 2009

We conduct a survey on mathematics academic achievement to 4th, 5th, and 6th grade elementary school students at Dong-Gu in Busan in order to provide teachers in elementary schools with basic research data. The survey questionnaire includes home background, private education, the difficulty degree of mathematics textbook, practical usage of computers, group-teaching, teaching methods, preview, review, homework amount, learning attitude, problem solving ability, interest for mathematics, and the relationships of a home room teacher and friends. Based on survey data we perform factor analysis to find major factors affecting mathematics academic achievement. We identify if there are statistically significant differences in responses of survey for gender group and grade group with regard to survey questions belonging to the major factors obtained in factor analysis.