• Bulletin of the Korean Mathematical Society
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• 제55권6호
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• pp.1783-1789
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• 2018

This paper treats the class of normalized logharmonic mappings $f(z)=zh(z){\overline{g(z)}}$ in the unit disk satisfying ${\varphi}(z)=zh(z)g(z)$ is analytically typically real. Every such mapping f admits an integral representation in terms of its second dilatation function and a function of positive real part with real coefficients. The radius of starlikeness and an upper estimate for arclength are obtained. Additionally, it is shown that f maps the unit disk into a domain symmetric with respect to the real axis when its second dilatation has real coefficients.

• Research in Mathematical Education
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• 제9권3호
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• pp.275-284
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• 2005

Tessellations are the pattern of iterations of geometric symmetry and translation. We can find them in the works of Escher who is the famous Dutch artist, and the American Indean life. Also, we can find the beauty of tessellations in the Korean traditional house door, Buddist temple architecture, palace's fence, etc. In the article, the figures of patterns we present are bird, fish, cat, pig, elephant, penguin, child and horse riding man, including Escher's, which are constructed using the computer geometric program, GSP (Geometer's Sketchpad). We want to talk about girl's disposition toward mathematics related to the figures. If they are supported by this kind of interesting figures constructed by their own hands, students will have more interest in learning geometric figures.

• Industrial Engineering and Management Systems
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• 제10권2호
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• pp.170-177
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• 2011

We present an improved binomial method for pricing financial deriva-tives by using cell averages. After non-overlapping cells are introduced around each node in the binomial tree, the proposed method calculates cell averages of payoffs at expiry and then performs the backward valuation process. The price of the derivative and its hedging parameters such as Greeks on the valuation date are then computed using the compact scheme and Richardson extrapolation. The simulation results for European and American barrier options show that the pro-posed method gives much more accurate price and Greeks than other recent lattice methods with less computational effort.

• Journal of the Korean School Mathematics Society
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• 제21권4호
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• pp.445-467
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• 2018

In this study, we analyzed the contents of pi and the area of a circle presented in Korean, Japanese, Singapore, and American mathematics textbooks, and drew implications for the teaching of pi and the area of a circle in school mathematics. We developed a textbook analysis framework by theoretical discussions on the concept of the pi based on the various properties of pi and the area of a circle based on the central ideas of measurement and the previous researches on pi and the area of a circle in elementary mathematics. We drew five suggestions for improving the teaching of pi and three suggestions for improving the teaching of the area of a circle in Korean elementary schools.

• Clinics in Shoulder and Elbow
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• 제22권4호
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• pp.173-182
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• 2019

Background: Patient reported outcome measures assess clinical progress from the patient's perspective. This study explored the relationship between shoulder outcome measures (The Disability of the Arm, Shoulder and Hand [DASH], American Shoulder and Elbow Surgeons Standard Shoulder Assessment score [ASES], and Constant score) by comparing the best possible scores obtained in an asymptomatic population compared to overall perception of health, as measured by the SF-36 outcome measure. Methods: Volunteers (age range, 20-69 years) with asymptomatic shoulders and no history of shoulder pain, injury, surgery, imaging, or pathology (bilaterally) were included. The DASH and ASES measures were completed by 111 volunteers (72 female, 39 male), of which 92 completed the Constant score (56 female, 36 male). The SF-36 was completed by all volunteers (level of evidence: IV case series). Results: The mean (${\bar{x}}$) score for ASES measure on the right shoulder was higher for the left-hand dominant side (${\bar{x}}=100.00$ vs. 95.02, p-value<0.001); no other significant differences. Better SF-36 scores were associated with better DASH scores. Our prediction models suggest that perception of overall health affects the DASH scores. Sex affected all three shoulder measures scores. Conclusions: Comparing scores of shoulder outcome measures to the highest possible score is not the most informative way to interpret patient progress. Variables such as health status, sex, and hand dominance need to be considered. Furthermore, it is possible to use these variables to predict scores of outcome measures, which facilitates the healthcare provider to deliver individualized care to their patients.

• School Mathematics
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• 제12권1호
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• pp.1-15
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• 2010

The study presented in this paper, which serves as a pilot study for a future comprehensive project, was to investigate how students deal with the concepts of infinity and limit. Based on the communicational approach to cognition, according to which mathematics is a kind of discourse, we tried to identify the characteristics of students' discourse on the topics. Four American and four Korean students were interviewed in English on limits and infinity and their discourse was scrutinized with an eye to common characteristics as well as culture, age, and education-related differences.

• School Mathematics
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• 제15권2호
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• pp.353-367
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• 2013

A mathematics pre-service teacher T analyzed American mathematics textbooks and developed his teaching material for instruction. This study analyzed his thinking processes and results in the view of semiotics. If we regard the textbook as a sign and the unitary conversion that students should learn as an object of the sign, the interpretant of the sign is the pre-service teacher's analysis, which is conducted at the aspects of a subject matter knowledge and student understanding. T interpreted the textbook versatilely in terms of his knowledges and experiences. He developed his teaching materials as diagrams, did the diagrammatic thinking and became to have the hypostatic abstraction. This study is significant because it used semiotics for explaining T's thinking process.

• Journal for History of Mathematics
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• 제26권1호
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• pp.21-32
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• 2013

The outbreak of the First and the Second World Wars cast great shadow across the Europe including mathematical society. The IMU led by French mathematicians after the First World War ceased to exist because it was used politically. As Europe ran into the Second World War, all the international mathematical activities were ceased. Prominent mathematicians were put into camp by Nazi or moved to the United States of America. After the war, European mathematicians did not have capacity to represent the international mathematical society anymore. This led Stone and other American mathematicians to form the new IMU, which was independent of political ideology. This paper studies the birth process of the new IMU after the War and some major events that happened to ICM in 1950s.

• The Mathematical Education
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• 제58권2호
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• pp.225-237
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• 2019

The picture of the mathematics curriculum should carry the complex role of relieving the difficulties of mathematics while conveying the core of the mathematics contents well. This study examined the precedence of picture and text harmony and the importance of emotional expression. The discussion of children's picture books became an important reference in this process. The understanding of the child's psychology and cognitive characteristics in the long history of picture books and the insight into the relationship between text and pictures will be important guidelines for elementary school textbooks. Based on these previous studies, this study found some impressive examples of Chinese, Japanese, Indian, and American textbooks on the two complementary relationships between paintings and texts and emotional expressions of paintings. If necessary, we compared these textbooks with Korean textbooks. Through this analysis, this study draws some implications for Korean textbook drawing and textbook production process. That is, the process of reading the picture and interpreting its meaning should be treated as part of the study of mathematics. The mathematical concepts to be dealt with or the sentence description of the problem should be concurrent with the design of the picture. The monotonous expressions and dialogues of characters in textbooks should be avoided, and the personality and emotions of characters should be more abundant and freely expressive.

• Journal of Educational Research in Mathematics
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• 제15권4호
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• pp.445-459
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• 2005

Statistics education is considered within the mathematics curriculum and, thus, can be integrated into other areas of mathematics. However, statistical concepts and thinking skills have to be considered as very different from those of other areas. It is possible to make statistics more meaningful for the learner by making definitions or explanations of concepts in textbooks more clear and consistent. In 'Math I' and 'Probability & Statistics' of the 7th curriculum, the definitions of sample standard deviation are different, which might confuse students. In this study, firstly, some issues relevant to sample standard deviation concept are discussed through the analysis in terms of didactical situation and curriculum. Secondly, the characteristics of sample standard deviation concept as a scholarly knowledge are examined. Finally, the characteristics of didactic transposition of sample standard deviation concept in Japanese, American, and British textbooks are investigated and some suggestions are elicited.