• Journal of the Korean School Mathematics Society
• /
• v.7 no.2
• /
• pp.99-116
• /
• 2004

This study investigates the concept of irrational number which middle school students begin to learn for the first time in their learning mathematics. Further, this explores how that concept is being taught, how much students understand that concept and things that students have difficulty in understanding relating to the concept of irrational number. Thus we try to figure out how the concept of irrational number should be taught for the most effective students' understanding. Thus, we want to provide some suggestions for teaching and learning irrationals numbers.

• Journal of Educational Research in Mathematics
• /
• v.16 no.4
• /
• pp.297-312
• /
• 2006

As research on the instruction method of the concept of irrational numbers, this thesis is theoretically based on the Freudenthal's Mathematising Instruction Theory and a conducted case study in order to find an introduction method of irrational numbers. The purpose of this research is to provide practical information about the instruction method ?f irrational numbers. For this, research questions have been chosen as follows: 1. What is the introducing method of irrational numbers based on the Freudenthal's Mathematising Instruction Theory? 2 What are the Characteristics of the teaming process shown in class using introducing instruction of irrational numbers based on the Freudenthal's Mathematising Instruction? For questions 1 and 2, we conducted literature review and case study respectively For the case study, we, as participant observers, videotaped and transcribed the course of classes, collected data such as reports of students' learning activities, information gathered through interviews, and field notes. The result was analyzed from three viewpoints such as the characteristics of problems, the application of mathematical means, and the development levels of irrational numbers concept.

• The Mathematical Education
• /
• v.62 no.1
• /
• pp.35-55
• /
• 2023

The purpose of this study is to examine not only students' cognition in the mathematical error-finding activity of the concept of irrational numbers, but also the students' learning stance regarding the use of errors and a teacher's questioning strategies that lead to changes in the level of mathematical discourse. To this end, error-finding individual activities, group activities, and additional interviews were conducted with 133 middle school students, and students' cognition and the teacher's questioning strategies for changes in students' learning stance and levels of mathematical discourse were analyzed. As a result of the study, students' cognition focuses on the symbolic representation of irrational numbers and the representation of decimal numbers, and they recognize the existence of irrational numbers on a number line, but tend to have difficulty expressing a number line using figures. In addition, the importance of the teacher's leading and exploring questioning strategy was observed to promote changes in students' learning stance and levels of mathematical discourse. This study is valuable in that it specified the method of using errors in mathematics teaching and learning and elaborated the teacher's questioning strategies in finding mathematical errors.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.34 no.4
• /
• pp.53-61
• /
• 1997

1. 가시적인 PM(Product Model)의 구조와 자료구조의 미존재로 PM의 실체가 아직 개념적 수준에 머무르고 있다. 2. Physical통합 PM보다 Logical 통합 PM이 요구된다. 3. 광의의 PM 보다 협의의 PM개념에 의한 시스템 개발이 요구된다. :Step by Step 4. PM이 반드시 문제해결의 만병통치약은 아니다. 5. 설계.생산.관리의 각 부문별 고유특성을 살리고 무리한 단일 PM개발보다 Interface 가능을 갖는 중간자의 개발(경우에 따라서 직접 Access 할 수도 있음.) 을 통해 각 부문별 정보의 PM으로의 표현을 용이하게 하여야 한다. 6. 기존의 시스템, 개발중인 시스템, 개발예정 시스템등을 무리없이 순조롭게 통합하기 위해서는 현실적인 정보통합수단으로서의 PM 설계가 요구된다. 7. 생산현장의 각 공정별 자동화 설비 및 운용 소프트웨어, 이것으로부터 생성되는 각종 정보등을 관리할 수 있는 공정 별 생산정보시스템은 필수적으로 요구되는 시스템이다. 8. 자동화된 생산시스템에서의 PM과 생산현장의 POP(Point of Porduction)시스템과의 연계는 필수적이다.

• 한국정보교육학회:학술대회논문집
• /
• 2008.01a
• /
• pp.136-141
• /
• 2008

창의적 문제 해결 능력을 컴퓨터 교육을 통해 이루려면 기존 컴퓨터 교육에 창의성과 문제해결력의 요소가 첨가되어야 한다. 또한, 학생들의 수준과 흥미를 고려하기 위해 어려운 컴퓨터에 관한 개념이나 원리를 다양한 교수학습 방법을 개발 활용하여 학생들이 쉽게 접근할 수 있는 노력이 필요하다. 아무리 좋은 교육이라 해도 학생들이 흥미와 관심을 갖고 학습을 하지 못하면 원하는 효과를 얻지 못할 것이다. 그러므로 컴퓨터 원리를 학생들이 이해하기 쉽도록 학생들이 좋아하는 게임 형식으로 개발하여 학생들이 직접 활동을 통해 자연스럽게 원리를 이해하고, 창의적인 사고력과 문제해결력을 증진시킬 수 있는 '컴퓨터 원리를 소재로 한 놀이'를 개발하고자 한다.

• Journal of Korean Society of Transportation
• /
• v.16 no.2
• /
• pp.133-144
• /
• 1998

양방향 2차로 도로는 우리나라 전체 포장도로 연자의 84%를 차지하고 있다. 양방향 2차로 도로의 효율성 및 교통류의 운영상태를 파악하기 위한 서비스 수준 척도로 지체시간의 백분율이 많이 사용되고 있다. 지체시간의 산정은 특정 도로 설계구간을 추원금지구간으로 설계할 것이지, 예산을 더 투자하여 선형을 개선함으로써 추원가능 구간으로 설계할 것인지에 대한 판단 기준을 제시할 수 있기 때문에 도로설계과정에 있어서 매우 중요하다. 본 연구에서는 저속차량의 확률적 분포를 고려하여 추원금지구간에서 발생하는 지체시간을 산정할 수 있는 모형을 제시하였다. 모형식이 기존에 확률적 분포를 고려하여 추월금지구간에서 발생하는 지체시간을 산정할 수 있는 모형을 제시하였다. 모형식이 기존에 개발된 거시적 수학적 모형에 비해 비교적 단순하고 입력변수도 수집이 용이한 점이 특징이라 할 수 있다. 모형의 신뢰성을 현장데이터를 이용하여 검증한 결과, 모혀으이 예측값이 근사적으로 츠덩한 실제 지체시간을 포함하는 긍정적인 결과를 도출하였다. 그러나 모형의 예측값 범위가 넓어 실용적인 MOE로 사용하기에 다소 무리가 있을 것으로 판단되므로, 개략적인 평가기준으로 모형이 예측한 값의 평균값을 보정하여 사용할 것을 제안한다. 모형의 신뢰성을 높이기 위해서는 본 연구에서 가정한 확률분포식에 대한 추가적인 검증이 필요할 것으로 판단된다. 본 연구는 실제 상황을 표현하는데 있어 확률적 개념의 도입과 이러한 새로운 접근방법의 기초를 마련한 측면에서 의미를 갖는다. 또한, 양방향 2차로 도로에서의 지체시간은 실제 소요시간과 자유운행시 즉 다른 차량의 영향을 받지 않았을 때의 속도 및 운영시간과의 차이로 정의한 바, 실제 지체시간을 현장자료를 통해 구하기란 현실적으로 불가능하므로, 본 연구에서는 이러한 제약점을 극복할 수 있는 근사적인 지체시간을 계산하는 방법을 제시한 점에서 의미를 갖을 수 있다.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.9 no.5
• /
• pp.147-157
• /
• 2019

In this study, mathematics education program was developed for the foreign students who entered the science and engineering college of Korea in order to improve their basic competency and to prevent dropouts. It is applied to 5 Chinese students, 4 male students and 1 female student. Three students are majoring in engineering college and two students are majoring in natural science college. Before applying the mathematics education program to foreign students, most students did not draw a graph of the 'irrational function' and the 'exponential function' and did not understand the concept of the 'limit' at all. However, after applying the mathematics program, all foreign students were able to draw graphs of the various function and the limit values were calculated accurately. Through the results of this study, the researcher proposes some of the following. When developing mathematics education programs for foreign students, it is very important to develop teaching materials suitable for their level. Textbook developers need to select and organize contents that are essential for learning in university mathematics and to present mathematical concepts and examples considering the Korean language level of foreign students. Moreover, it will be necessary to try to present mathematical terms commonly used in Korea in their native language or English.

• School Mathematics
• /
• v.11 no.3
• /
• pp.527-546
• /
• 2009

This study was designed to gain insights into instrumental genesis process of CAS in Korean high school students and to explore its practical potentials in secondary mathematics education. Two activities, such as Concept-Centered Mathematics Activity based on CAS and Problem Solving Activities, were constructed and executed to 10th Grade seven students for twelve class hours. The finding on the students' activities are as follows : it is meaningful in mathematics education, especially in algebra education, in that the CAS based concept centered mathematics activity offers great opportunities to deal with high-qualified application problems. The problem solving activities based on the instrumented CAS may have an influence on the sequence of mathematics curriculum, e.g. the optimization problems may precede the calculus problems such as derivatives in high school. The results of this study to investigate the instrumental genesis of CAS in mathematical activities will give insights into the secondary mathematics curriculum to prepare the CAS in Korea.

• Journal of Energy Engineering
• /
• v.12 no.4
• /
• pp.289-301
• /
• 2003

To develop a chemical-looping combustion technology, conceptual design of 50 kW thermal chemical-looping combustor, which is composed of two interconnected pressurized circulating fluidized beds, was performed by means of mass and energy balance calculations. A riser type fast fluidized bed was selected as an oxidizer and a bubbling fluidized bed was selected as a reducer by mass balance for the chemical-looping combustor. Calculated values of bed mass, solid circulation flux, and reactor dimension by mass and energy balance calculations were suitable for construction and operation of chemical-looping combustor. It is concluded from the comparison of the design results and operating values of commercial circulating fluidized bed that the process outline is realistic. Moreover, the previous results support that oxygen carrier particle, NiO/bentonite, fulfills the conversion rates needed for the proposed design. The effects of system capacity, metal oxide content in a oxygen carrier particle, amount of steam input, gas velocity, and solid depth on design values were investigated and the changes in the system performance can be estimated by proposed design tool.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.4
• /
• pp.83-90
• /
• 2018

Considering the increased threats from worldwide terrors and the increased demands on the blast resistant design of commercial buildings, this study is aimed at understanding the basic concept of blast resistant design and evaluating the blast performance with an actual design example. Although there are many differences between earthquake and blast loads, the design concept against both loads is similar in terms of allowing the plastic behavior of a structure and sharing the ductile detailing. Through the blast performance evaluation of a target building provided in this study, it is noted that a well-designed building for the conventional loads can have a certain level of blast resistance. However, this cannot be generalized since the blast load on a structure varies depending on the type of weapon, TNT equivalence, standoff distance, etc. Architectural planning with positioning the sacrificial structure or maintaining a sufficient standoff distance from the expected detonation is the simple and effective way of improving the blast resistance of a building.