• Analytical Science and Technology
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• v.13 no.1
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• pp.41-48
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• 2000

A biosensor for the determination of hydrogen peroxide was constructed by immobilizing of porcine small instestinal tissue in a plain carbon paste, and the effect of varying the $H_2O_2$ concentration and pH on the rate of catalytic reaction was evaluated. For the mathematical simplicity, no mediator was added. Electrochemical properties and the maximal rate could be derived from the quantitative analysis of the observed phenomena related to the electrode reaction. Also, pH dependence of the Michaelis constant enabled to calculate various thermodynamic parameters and subsequently to design a electrochemical method to determine the optimum pH of enzyme.

• School Mathematics
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• v.17 no.4
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• pp.633-652
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• 2015

The purpose of the present study is twofold: one is to understand secondary mathematics teachers' capacity to sort out given tasks based on Stein & Smith(1998)'s Cognitive Demands of Mathematical Task Framework; the second is to examine how the teachers assess the levels of cognitive demand indicated in students' reponses and how they modify the tasks to elicit the students' higher levels of cognitive activity. The analysis of 45 teachers' responses to the survey indicates that the teachers, in general, could select appropriate tasks for the given goal of the lessons but some made the decision merely by their appearances. Even though the teachers chose a particular level with different reasons amongst each other, most teachers could correctly evaluate the levels of cognitive demand of the students' responses. Finally, teachers could pose cognitively demanding tasks using various methods, but a number of them felt challenged in creating word problems that were realistic and aligned with curriculum.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.194-198
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• 2005

Growth curves of Listeria monocytogenes in modified surimi-based imitation crab (MIC) broth were obtained by measuring cell concentration in MIC broth at different culture conditions [initial cell numbers, $1.0{\times}10^{2},\;1.0{\times}10^{3}\;and\;1.0{\times}10^{4}$, colony forming unit (CFU)/mL; temperature, 15, 20, 25, 37, and $40^{\circ}C$] and applied to Gompertz model to determine microbial growth indicators, maximum specific growth rate constant (k), lag time (LT), and generation time (GT). Maximum specific growth rate of L. monocytogenes increased rapidly with increasing temperature and reached maximum at $37^{\circ}C$, whereas LT and GT decreased with increasing temperature and reached minimum at $37^{\circ}C$. Initial cell number had no effect on k, LT, and GT (p > 0.05). Polynomial and square root models were developed to express combined effects of temperature and initial cell number using Gauss-Newton Algorism. Relative coefficients of experimental k and predicted k of polynomial and square root models were 0.92 and 0.95, respectively, based on response surface model. Results indicate L. monocytogenes growth was mainly affected by temperature and square root model was more effective than polynomial model for growth prediction.

• Journal of the Korea Society of Computer and Information
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• v.18 no.4
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• pp.113-121
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• 2013

In this paper, simulations were carried out to determine the efficiency of the rotation efficiency according to the draft of waterwheel in open rectangular channel. In the small hydroelectric generators to get the highest efficiency of waterwheel is very important. But the presence of various elements(free water surface flow, non-uniform velocity distribution because of the waterways wall friction etc) makes it difficult to create a mathematical formula. In this paper, we made a scale model and perform a physical simulation where the draft, gradient and flux is variable. Scale modelling with 10-step draft, 3-step gradients and 2-step flux, as well were constructed then computerized automatic experimental system were configured to acquire the rotational efficiency vs. draft of itself. Rotational efficiency is analyzed as for the draft of waterwheel using the acquired data by varying the gradient and flux of canal. Reviewing the analyzed data, it is confirmed that phenomena of efficiency shown at previous and present experiment is similar and revealed that computerized system shows more sophisticated numerical figures.

• Journal of the Korean School Mathematics Society
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• v.12 no.1
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• pp.131-149
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• 2009

A study on comprehension level of mathematical basic knowledge(MBK) of gifted students in middle school. The interest in mathematics gifted education is very high. However, in reality, there has been a shortage of the analysis of students' achievement result since mathematics gifted education began through the institute of gifted education in the education office in 2003. On this study, MBK is subdivided into definition, property and procedure and then examination questions arc developed on the basis of national level achievement standard. With these examination tools, total inspection was conducted in on metropolitan city and the result was analyzed. First, in a basic definition, relatively low achievement result was seen except the basic concept related operation. Second, in a basic property, very low achievement result was seen in the questions of basic property without basic definition and as a whole, the result was similar with the basic definition. Third, in basic procedure, the achievement result was very remarkable. This result shows we need tn increase the comprehension ability of MBK. To do this, the systematic alternative development of the questions of selecting gifted students and the contents of gifted education is required. This study proposes the meaningful implication to the selection question development related to the MBK and the improvement of gifted education contents. And it is expected to provide the positive change for mathematics gifted education.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.1
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• pp.71-104
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• 2016

The aim of this study is to look into the didactical background for teaching percent in elementary school mathematics and offer suggestions to improve teaching percent in the future. In order to attain these purposes, this study examined key ideas with respect to the didactical background on teaching percent through a theoretical consideration regarding various studies on percent. Based on such examination, this study compared and analyzed textbooks used in the United States, the United Kingdom, and South Korea. In the light of such theoretical consideration and analytical results, this study provided suggestions for improving teaching percent in elementary schools in Korea as follows: giving much weight on percent, emphasizing the concept of percent as a ratio, underlining the various kinds of change problems, emphasizing informal strategies of students before teaching the percent formula, and utilizing various models actively.

• Journal of the Korea Convergence Society
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• v.9 no.6
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• pp.209-215
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• 2018

The college liberal arts mathematics is opened as a required course in science and engineering field, but students with low achievement experience difficulty in learning. Therefore, flip learning, which is well known as an effective teaching method based on self-led and learner, is suggested as an alternative. However, some problems are pointed out in this pedagogy. As an alternative to flip learning, we apply flip PBL classes that apply PBL to flip learning to general math subjects to supplement the problems of existing flip learning classes and increase interest in mathematics I want to know the effectiveness of whether it can be done. In this study, we investigated the educational effectiveness of the comparison study between the experimental group applying flip PBL class and the control group applying the existing flip learning class. First, the experimental group showed higher than the control group by 22 points Second, in the reflection journal analysis, in contrast to the control group, there was a positive effect on the improvement of the interest of the mathematics in the experimental group, It is expected that it will be applied as a teaching method that can complement the learning.

• Journal of Elementary Mathematics Education in Korea
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• v.13 no.2
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• pp.193-210
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• 2009

This research were to develop and apply an educational program for 6th grade students in mathematics by using level orientated teaching method and to make an analysis of their effects on students' mathematics learning achievements and mathematical disposition. Those purposes is following: First, we develop the level orientated teaching method that fits to the low level and high level students and analyze the effect on students' mathematics learning achievements. Second, we analyze the effect on students' mathematical disposition by using level orientated teaching method. The biggest problem of applying level orientated teaching method is that all the groups should do the meaningful activity while just one group is on process. So we tried to keep the proposition that level orientated teaching method should be helpful to both high and low level students. The duration of the research was about 8 weeks from march 2 to may 22 and the level orientated mathematics program consists in lesson 1 "a fraction and a decimal" to lesson 3 "The range of numbers". The results of this study are as follows : First, there was significant effect to the students, develop level orientated mathematics program and using that program. Second, there was an affirmative effect to the students about mathematical disposition using level orientated mathematics program. To sum up conclusion of this study, the level orientated mathematics program has an affirmative effect on mathematics learning achievements and mathematical disposition. We expect further research about level orientated teaching method and use effective level orientated teaching method widely.

• School Mathematics
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• v.13 no.2
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• pp.267-286
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• 2011

In this paper I investigated the historical developments of the algorithms for multiplication of natural numbers. Through this analysis I tried to describe more concretely what is to understand the common algorithm for multiplication of natural numbers. I found that decomposing dividends and divisors into small numbers and multiplying these numbers is the main strategy for carrying out multiplication of large numbers, and two decomposing and multiplying processes are very important in the algorithms for multiplication. Finally I proposed some implications based on these analysis.

• Journal for History of Mathematics
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• v.21 no.4
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• pp.105-126
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• 2008

This article summarizes the historical changes of the secondary school geometry to give insights into the new direction of geometry education for the 21th century. Geometry has been considered as an essential subject in high school since mid-nineteen century in accordance with the social changes. Since the development of computer softwares such as CAD effects on the role of geometry in work and professional societies, the knowledge and skills the contemporary world require to school geometry have being changed. More focus on applications and modeling aspects, expansion of reasoning and problem solving, emphasis on design-related elements are features of the school geometry for the new century.