• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.12B
• /
• pp.1736-1743
• /
• 2011

In Network Centric Warfare (NCW) environment, having a tactical communication network which provides high data exchange rate is very important. In the process, Korean Army developed Mobile Subscriber Access Point (MSAP) which is based on the commercial Wireless BroadBand (Wibro). MSAP is a vehicle attached base station which provide high data exchange communication environment in a given area. Thus MSAP can provide high data exchange rate and mobility to accomplish missions in the battlefield more effectively. In this paper, we propose an operational strategy of using MSAP to provide tactical communication network in the battlefield. The idea is to find the optimal location point of the MSAP in the operational area where all the troops in the operational area can be supported by the MSAP with a minimum number of MSAP. Since the current Korean Army's basic idea of using MSAP is just distribute this MSAP to each troop, so by applying our strategy we can save MSAP devices for more flexible operation. We will show our strategy's benefits through the mathematical model and the algorithm of the presented problem.

• The Mathematical Education
• /
• v.59 no.4
• /
• pp.405-420
• /
• 2020

There have been mixed reports about the idea of utilization of resources developed from one discipline across disciplinary areas. Grounded with the argument that critical thinking is not domain-specific (Mulnix, 2012; Vaughn, 2005), we developed a theoretical model of intellectual resources (IR) that students develop and use when learning and doing mathematics and science. The theoretical model shows that there are two parallel epistemic practices students engage in science and mathematics - searching for reasons and giving reasons (Bailin, 2002; 2007; Mulnix, 2012). Applying Confirmatory Factor Analysis and Structural Equation Model to the data of 9,300 fourth grade students' responses to standardized science and mathematics assessments, we verified the theoretical model empirically. Empirically, the theoretical model is verified in that fourth graders do use the two epistemic practices, and the development of parallel practices in science impacts the development of the two practices in mathematics: A fourth grader's ability to search for reasons in science affects his or her ability to search for reasons in mathematics, and the ability to give reasons in science affects the same ability use in mathematics. The findings indicate that educators need to open ideas of sharing development of epistemic practices across disciplines because students who developed intellectual resources can utilize these in other settings.

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

• Communications of Mathematical Education
• /
• v.29 no.1
• /
• pp.91-110
• /
• 2015

The purpose of this study is to investigate the understanding of pi of elementary gifted students and explore improvement direction of teaching pi. The results of this study are as follows. First, students understood insufficiently the property of approximation, constancy and infinity of pi from the fixation on 'pi = 3.14'. They mixed pi up with the approximation of pi as well. Second, they had a inclination to understand pi as algebraic formula, circumference by diameter. Third, few students understood the property of constancy and infinity of pi deeply. Lastly, the discussion activity provided the chance of finding the idea of the property of approximation of pi. In conclusion, we proposed several methods which improve the teaching of pi at elementary school.

• Communications of Mathematical Education
• /
• v.23 no.2
• /
• pp.231-253
• /
• 2009

This paper investigated the views of effective mathematics instruction on the part of teachers. The study was carried out a survey with 223 elementary school teachers in Korea. The questionnaire consisted of the following 4 main categories with a total of 48 factors: (a) the curriculum and content, (b) teaching and learning, (c) classroom environment and atmosphere, and (d) assessment. Some ideas teachers revealed about what would enable good mathematics teaching coincided with previous research. Specifically, teachers agreed with the idea of consideration of students' individual differences or focus on concepts. However, there were differences with regard to the use of technology and the importance of learning environment, which have been emphasized in mathematics education literature. Considering that the teacher plays a key role in implementing good instruction, this paper emphasizes us to attend to teachers' perspectives in order to initiate good teaching at the actual classroom.

• Journal for History of Mathematics
• /
• v.24 no.3
• /
• pp.37-58
• /
• 2011

The development of recent Mathematical Logic is mostly originated in Hilbert's Proof Theory. The purpose of the plan so called Hilbert's Program lies in the formalization of mathematics by formal axiomatic method, rescuing classical mathematics by means of verifying completeness and consistency of the formal system and solidifying the foundations of mathematics. In 1931, the completeness encounters crisis by the existence of undecidable proposition through the 1st Theorem of G?del, and the establishment of consistency faces a risk of invalidation by the 2nd Theorem. However, relative of partial realization of Hilbert's Program still exists as a fruitful research program. We have tried to bring into relief through Curry-Howard Correspondence the fact that Hilbert's program serves as source of power for the growth of mathematical constructivism today. That proof in natural deduction is in truth equivalent to computer program has allowed the formalization of mathematics to be seen in new light. In other words, Hilbert's program conforms best to the concept of algorithm, the central idea in computer science.

• Communications of Mathematical Education
• /
• v.37 no.1
• /
• pp.85-104
• /
• 2023

The purpose of this study is to analyze the types of mathematics journals of elementary school students and to understand how they change in mathematics journals as the grade goes up, and to obtain implications in mathematics education. To this end, 170 of the 222 parish mathematics data submitted to the "Math Journal Contest" were analyzed with the consent of both minors and their parents. As for the framework for analyzing math journal types, 12 types were derived through independent analysis between three researchers. The research results showed that first, the type of math journal written by elementary school students is a variety of journals, such as observation, problem making, concept organization, and review. In addition, as a learning area, it was found that math journal showed a noticeable increase in experimental observation, problem making, and concept journal as the grades progressed, while a small number of idea journal and explanatory journals appeared. However, game (winning) strategy building and types declined. It can be seen that this is evolving from a type that requires activity-oriented or simple descriptions to a type that actively applies mathematical concepts. As such, there are 12-type of math journals, but it is necessary to actively use the teaching materials in writing that can be freely expressed in the school setting.

• The Mathematical Education
• /
• v.61 no.2
• /
• pp.287-303
• /
• 2022

The purpose of this study is to draw implications for the improvement in the CSAT by analyzing structures and tasks in the Abitur. To this end, it analyzes the mathematics test system with a focus on the basic and advanced level examination systems, the operator, the using technology, and mathematical formulas. And the characteristics of tasks in the 2021 Abitur were analyzed. As a result of the analysis, first, Germany evaluates whether students have the competency emphasized in the curriculum at Abitur. Second, Germany, which emphasizes the proper use of technology, utilizes both tasks that use technology and those that do not in the Abitur. Third, the Abitur consists of most of the tasks using promised operators and uses various types of operators to present various types of questions to evaluate competence. Fourth, the Abitur includes not only simple structured items consisting of 2-3 subtasks but also tasks dealing in depth with a single situation centered on a big idea. Finally, mathematical justification and proof play an important role in the Abitur. Based on this, some specific measures for improving the CSAT were suggested.

• Korean Journal of Computational Design and Engineering
• /
• v.6 no.1
• /
• pp.24-30
• /
• 2001

An efficient and robust algorithm to compute the exact Voronoi diagram of a circle set is presented. The circles are located in a two dimensional Euclidean space, the radii of the circles are non-negative and not necessarily equal, and the circles are allowed to intersect each other. The idea of the algorithm is to use the topology of the point set Voronoi diagram as a seed so that the correct topology of the circle set Voronoi diagram can be obtained through a number of edge flipping operations. Then, the geometries of the Voronoi edges of the circle set Voronoi diagram are computed. In particular, this paper discusses the topological aspect of the algorithm, and the following paper discusses the geometrical aspect. The main advantages of the proposed algorithm are in its robustness, speed, and the simplicity in its concept as well as implementation. Since the algorithm is based on the result of the point set Voronoi diagram and the flipping operation is the only topological operation, the algorithm is always as stable as the Voronoi diagram construction algorithm of a point set.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.19 no.5
• /
• pp.422-430
• /
• 2014

This study proposes a small-signal model and control design for a two-stage DC-DC-AC converter to investigate its dynamic characteristics in relation to battery energy storage system. When the circuit analysis of the two-stage DC-DC-AC converter is attempted simultaneously, the mathematical procedure of deriving the dynamic equation is complex and difficult. The main idea of modeling the two-stage DC-DC-AC converter states that this topology is separated into a bidirectional DC-DC converter and a single-phase inverter with an equivalent current source corresponding to that of the inverter or converter. The dynamic equations for the separated converter and inverter are then derived using the state-space averaging technique. The procedures of building the small-signal model of the two-stage DC-DC-AC converter are described in detail. Based on the derived small-signal model, the individual controllers are designed through a frequency-domain analysis. The simulation and experimental results verify the validity of the proposed modeling approach and controller design.