• Communications of Mathematical Education
• /
• v.32 no.4
• /
• pp.455-475
• /
• 2018

The purpose of this study is to investigate characteristics of pre-service teachers' cognition about learning through the use of technology by employing a teacher education program in the use of technology-friendly flipped classroom. For this purpose, 45 pre-service teachers participated in the study and they completed both pre- and post-surveys including questions about Technology Adopter Category Index(TACI) and Technological Pedagogical Content Knowledge(TPACK). They were also asked to write self-reflections on mathematics softwares(Geometer's Sketch Pad(GSP), Geogebra, Cabri 3D). Results show that the teacher education program in the use of technology-friendly flipped classroom affected pre-service teachers' cognitions of TACI and TPACK, and they perceived that technology integration helped students' mathematics learning process. Findings from this study indicate that ideas about how to develop a technology-friendly teacher education program are more specified..

• Journal of the Korean School Mathematics Society
• /
• v.23 no.4
• /
• pp.449-468
• /
• 2020

TIMSS is a representative international comparative study that analyzes changes in mathematics and science achievement, and it collects information on the educational system, curriculum, teaching and learning situation of participating countries as well as research and check, and provides implications for each country's mathematics and science education. Although domestic TIMSS studies focused on the results of achievement related to the evaluation of mathematics, not many have taken a closer look at the content and characteristics of the assessment framework. Therefore, the purpose of this study was to analyze the characteristics of the TIMSS 2019 mathematics assessment framework, and to derive implications for the mathematics curriculum and mathematics learning by examining the students' study time in light of the Korean mathematics curriculum. The implications derived from the results of this study are summarized as follows: First, it is necessary to check the connection between content elements in the mathematics and education process. Second, it is necessary to check the appropriateness and connectivity of the learning timing of the content elements in the mathematics and education courses. Finally, it is necessary to verify that the hierarchy of content areas and the structure of content systems in mathematics and education courses are consistent with the direction of mathematics education at the international level. This study can be used as a basis for mathematics and curriculum revisions, and can be used to set directions for the development of large-scale evaluation frameworks.

• Journal for History of Mathematics
• /
• v.20 no.3
• /
• pp.127-146
• /
• 2007

From 1876 to 1883, British mathematician James Joseph Sylvester worked as the founding head of Mathematics Department at the Johns Hopkins University which has been known as America's first school of mathematical research. Sylvester established the American Journal of Mathematics, the first sustained mathematics research journal in the United States. It is natural that we think this is the most exciting and important period in American mathematics. But we found out that the International Congress of Mathematicians held at the World's Columbian Exposition in Chicago, August 21-26, 1893 was the real turning point in American's dedication to mathematical research. The University of Chicago was founded in 1890 by the American Baptist Education Society and John D. Rockefeller. The founding head of mathematics department Eliakim Hastings Moore was the one who produced many excellent American mathematics Ph.D's in early stage. Many of Moore's students contributed to build up real American mathematics research power in early 20 century The University also has a well-deserved reputation as the "teacher of teachers". Beginning with Sylvester, we analyze what E.H. Moore had done as a teacher and a head of the new department that produced many mathematical talents such as L.E. Dickson(1896), H. Slaught(1898), O. Veblen(1903), R.L. Moore(1905), G.D. Birkhoff(1907), T.H. Hilderbrants(1910), E.W. Chittenden(1912) who made the history of American mathematics. In this article, we study how Moore's vision, new system and new way of teaching influenced American mathematical society at early stage of the top class mathematical research. and the meaning that early University of Chicago case gave.

• Journal of Educational Research in Mathematics
• /
• v.26 no.4
• /
• pp.819-834
• /
• 2016

As a method to lead a change in mathematics education, recently reformation of assessment appears as a concept of process-focused assessment. Process-focused assessment is the concept that 2015 revised mathematics curriculum aims for, which is promoted also in policy. This research suggested a significance of process-focused assessment that has not been determined in conceptualization and the practical model. For this, this research investigated the content of the assessment on 2015 revised mathematics curriculum, and explored process-focused assessment based on the recent education assessment theory and research. Also, we suggested a model of practical plan by investigating the condition to perform the process-focused assessment. This research could take a basic role to practice process-focused assessment and investigate the concrete plan in the mathematics class field.

• Journal of the Korean School Mathematics Society
• /
• v.12 no.3
• /
• pp.347-364
• /
• 2009

In this paper, the researchers investigated the influence of graphing calculator in learning the concept of linear function for the gifted students. Elementary students who were taking a course in enrichment mathematics at Science Education Institute for the Gifted in Mokpo National University were selected for this study. The researchers analyzed students' processes of mathematical inference and conjecture, and students' algebraic description. We found the facts that the visualization using a graphing calculator and CBL is helpful to the gifted students in understanding concepts of liner function, finding the relationship between variables, analyzing and presupposing of graph. But, using graphing calculator can be a factor that disturbs learning of students who have too much of curiosity on graphing calculator.

• Journal of Korea Society of Industrial Information Systems
• /
• v.9 no.4
• /
• pp.8-15
• /
• 2004

Gilding process make thin membrane with other metals to surface of metal and metalloid. It control the hydrogen ion and oxalic acid density with rinsing work since the process used to acid and alkali. Therefore, in this study, several control method applied the gilding process. It desired to the optimal controller and their results can be save on water resource by useful feed of rinsing. And there is quite a possibility of uniform production due to fixed control of acid and alkali. Also it can be contributed the competition power because of lower production unit cost. Especially, this control method to be developed can be applied to any process without mathematical model. And it can be changed their algorithm more easily, if control object is changed.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.19 no.12
• /
• pp.2439-2447
• /
• 1994

In this paper, We analyze Colpitts type voltage contrqlled oscillator(VCO) used in personal handheld phone using a nonlinear analysis with third-order model. The resul shows the non-exponentially decaying shifting bias superimposed on the oscillator output which is different with the exponentially decaying shifting bias from the linear analysis. The stable oscillation criterion during a frequency change in a design of VOC can be also determined using proposed non-linear analysis. The theory is confirmed using PSPICE simulation and the experimental result of GaAs VCO matched very well with the theory.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.4 no.4
• /
• pp.53-61
• /
• 2000

능동 제어기를 설계하기 위해서는 제어대상 구조물의 수학모델의 구해야한다. 그러나, 무한차원의 구조물에 대하여 정확한 모델을 구하는 것은 불가능하므로 유한차원인 저차원화된 모델을 사용하여 제어기를 설계한다. 그러나, 실제 구조물과 저차원화된 모델사이의 오차에 의하여 제어기의 성능이 저하가 되면 제어기와 구조물의 상호작용, 지진과 같은 오란 등의 불확실성, 지진시 구조물의 동적 특성 변화로 인하여 제어기의 성능이 더욱 저하가 된다. 이러한 저하 요인은 제어기 설계시 요구되는 구조물의 수학모델에 대한 불확실한 요소로 작용하기 때문에 제어성능의 저하를 일으키며 응답의 불안정을 유발하기로 한다. 본 연구에서는 질량형 능동제어기(AMD)가 설치된 3층 건물 모형의 모델 오차에 관한 불확실성을 반영한 강인제어기법을 적용하여 제어성능과 안정성을 실험을 통하여 분석하였다. 강인제어 기법인 $\mu$ 합성법에 요구되는 여러 가지 가중함수인 주파수필터는 건물과 AMD의 특성, 모델 오차, 제어율과 AMD 성능의 , 측정잡음 및 지진외란의 특성 등을 고려하여 정량적으로 선택되었다. $\mu$합성법에 의하여 제어기를 설계하였으며 강인성을 비교하기 위하여 불확실성이 고려되지 않는 LQG 기법에 의한 제어기를 선택하였다. $\mu$합성법은 규정된 불확성에 대하여 제어의 강인성을 가지므로 동적특성이 바뀐 건물모형에 관한 강인성을 LQG 기법에 의한 제어성능과 비교하였다. 그 결과 동적특성이 변화된 건물에 대하여 $\mu$합성법만이 제어의 효율성이 유지되는 강인성을 나타내었다.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.7 no.4
• /
• pp.42-50
• /
• 1993

This paper was proposed drive strategy Induction Motor using the fuzzy algorithm of auto-tuning PID control. In fuzzy control, the 1M driving system is controlled in trial and error without the mathematical modeling and using fuzzy lookup table the real time control is possible. Also, ,dividing the fuzzy rules in several zone, the stability and response of the 1M driving system is improved. The parameters of 1M are varying according to the environmental conditions, the variance of the parameters is affected with the driving characteristics of 1M. Using the fuzzy algorithm of the driving system which has the auto tuning control function for high performance, high accuracy of the driving system, a designed and proposed through the comparision with the PID control method and the driving characteristics is reviewed and analyzed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.8
• /
• pp.3345-3351
• /
• 2012

In this study, simulation of an underwater platform system which is able to perform the underwater test is implemented to predict its dynamic characteristics. Accordingly, its governing equations are derived to construct the mathematical model. From the proposed model, the time in flooding and the pressure of ballast tank in blowing air to come up are predicted. In addition, simulation of the stability of the system for repulsive force of the tube by compressed air is carried out. Their results will be used to select valves, air tanks as well as design the system including ballast tanks. And they will help users operate it efficiently.