• School Mathematics
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• v.14 no.1
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• pp.29-43
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• 2012

This paper investigated the conceptual schemes in which four children constructed a strategy representing the situation as a figure and partitioning it related to the work which they quantify the result of partitioning to various types of fractions when an equal sharing situation was given to them in contextual or an abstract symbolic form of division. Also, the paper researched how the relationship of factors and multiples between the numerator and denominator, or between the divisor and dividend affected the construction. The children's partitioning strategies were developed such as: repeated halving stage ${\rightarrow}$ consuming all quantity stage ${\rightarrow}$ whole number objects leftover stage ${\rightarrow}$ singleton object analysis/multiple objects analysis ${\rightarrow}$ direct mapping stage. When children connected the singleton object analysis with multiple object analysis, they finally became able to conceptualize division as fractions and fractions as division.

• The Journal of the Acoustical Society of Korea
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• v.31 no.7
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• pp.427-434
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• 2012

The overlap-add technique based on waveform similarity (WSOLA) method is known to be an efficient high-quality algorithm for time scaling of speech signal. The computational load of WSOLA is concentrated on the repeated normalized cross-correlation (NCC) calculation to evaluate the similarity between two signal waveforms. To reduce the computational complexity of WSOLA, this paper proposes a fast NCC computation method, in which NCC is obtained through pre-calculated sum tables to eliminate redundancy of repeated NCC calculations in the adjacent regions. While the denominator part of NCC has much redundancy irrespective of the time-scale factor, the numerator part of NCC has less redundancy and the amount of redundancy is dependent on both the time-scale factor and optimal shift value, thereby requiring more sophisticated algorithm for fast computation. The simulation results show that the proposed method reduces about 40%, 47% and 52% of the WSOLA execution time for the time-scale compression, 2 and 3 times time-scale expansions, respectively, while maintaining exactly the same speech quality of the conventional WSOLA.

• East Asian mathematical journal
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• v.32 no.4
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• pp.565-587
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• 2016

The purpose of this study was to analyze the understanding of the meaning of fraction division and fraction division algorithm of elementary mathematical gifted students through the process of problem posing and solving activities. For this goal, students were asked to pose more than two real-world problems with respect to the fraction division of ${\frac{3}{4}}{\div}{\frac{2}{3}}$, and to explain the validity of the operation ${\frac{3}{4}}{\div}{\frac{2}{3}}={\frac{3}{4}}{\times}{\frac{3}{2}}$ in the process of solving the posed problems. As the results, although the gifted students posed more word problems in the 'inverse of multiplication' and 'inverse of a cartesian product' situations compared to the general students and pre-service elementary teachers in the previous researches, most of them also preferred to understanding the meaning of fractional division in the 'measurement division' situation. Handling the fractional division by converting it into the division of natural numbers through reduction to a common denominator in the 'measurement division', they showed the poor understanding of the meaning of multiplication by the reciprocal of divisor in the fraction division algorithm. So we suggest following: First, instruction on fraction division based on various problem situations is necessary. Second, eliciting fractional division algorithm in partitive division situation is strongly recommended for helping students understand the meaning of the reciprocal of divisor. Third, it is necessary to incorporate real-world problem posing tasks into elementary mathematics classroom for fostering mathematical creativity as well as problem solving ability.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.4
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• pp.521-539
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• 2016

The structures of partitive and quotitive division of fractions are dealt with differently, and this led to using partitive division context for helping develop invert-multiply algorithm and quotitive division for common denominator algorithm. This approach is unlikely to provide children with an opportunity to develop an understanding of common structure involved in solving different types of division. In this study, I propose two approaches, measurement approach and isomorphism approach, to develop a unifying understanding of fraction division. From each of two approaches of solving quotitive division based on proportional reasoning, I discuss an idea of constructing a measure space, unit of which is a quantity of divisor, and another idea of constructing an isomorphic relationship between the measure spaces of dividend and divisor. These ideas support invert-multiply algorithm for quotitive as well as partitive division and bring proportional reasoning into the context of fraction division. I also discuss some curriculum issues regarding fraction division and proportion in order to promote the proposed unifying understanding of partitive and quotitive division of fractions.

• Journal of Industrial Convergence
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• v.18 no.3
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• pp.27-34
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• 2020

For modern people living in the era of the 4th Industrial Revolution, appearance management and consumption behavior are very important factors not only in personal values but also in human relationships. It is used as an important means of competitiveness with skin beauty and fashion. It is used as an important means. Therefore, we compared and analyzed professionally from the aesthetic point of view about the makeup of the eyebrows, eyes, eye line, cheeks, lip make-up, and skin tone of Woohee, who appeared in the movie and Miss Korea in 1989. As a result of the study, other aspects were analyzed in the common denominator of a somewhat exaggerated makeup technique. Accordingly, through this study, it is possible to explore multiple angles for developing novel makeup patterns and items, and at the same time, it will help to establish a foundation for makeup beauty education. In addition, this study intends to contribute to the practical development with competitiveness by building a more aggressive marketing strategy in the makeup market.

• Journal of Preventive Medicine and Public Health
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• v.43 no.2
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• pp.174-184
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• 2010

Objectives: This study shows the issues that should be considered when applying standardized rates using Community Health Survey(CHS) data. Methods: We analyzed 2008 CHS data. In order to obtain the reliability of standardized rates, we calculated z-score and rank correlation coefficients between direct standardized rate and indirect standardized rate for 31 major indices. Especially, we assessed the change of correlations according to population composition (age and sex), and characteristics of the index. We used Mantel-Haenszel chi-square to quantify the difference of population composition. Results: Among 31 major indices, 29 indices' z-score and rank correlation coefficients were over 0.9. However, regions with larger differences in population composition showed lower reliability. Low reliability was also observed for the indices specific to subgroups with small denominator such as 'permanent lesion from stroke', and the index with large regional variations in age-related differences such as 'obtaining health examinations'. Conclusions: Standardized rates may have low reliability, if comparison is made between areas with extremely large differences in population composition, or for indicies with large regional variations in age-related differences. Therefore, the special features of standardized rates should be considered when health state are compared among areas.

• Journal of Korea Water Resources Association
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• v.38 no.10 s.159
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• pp.851-859
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• 2005

Normalized cross-correlation (correlation coefficient) is a useful measure for pattern matching in PIV (Particle Image Velocimetry) analysis. Because it does not have a corresponding simple expression in frequency domain, several fast but inexact measures have been used. Among them, three measures of correlation for PIV analysis and the normalized cross-correlation were evaluated with a sample calculation. The test revealed that all other proposed correlation measures sometimes show inaccurate results, except the normalized cross-correlation. However, correlation coefficient method has a weakpoint that it requires so long time for calculation. To overcome this shortcoming, a fast and exact method for calculating normalized cross-correlation is suggested. It adopts Fast Fourier Transform (FFT) for calculation of covariance and the successive-summing method for the denominator of correlation coefficient. The new algorithm showed that it is really fast and exact in calculating correlation coefficient.

• Lingua Humanitatis
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• v.8
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• pp.331-367
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• 2006

In this paper I attempted to investigate the matters related with the clarification of the close relationship between writing system and pronunciation. On the way of pursuing the research on the subject I found the fact that the same topic has been the main academic target in Korea. There have been some remarks about English alphabets and pronunciation. Nevertheless, the relation between alphabet codes and pronunciation tokens wasn't considered as the main key to master the English pronunciation correctly and completely. As the main target of this paper I argue that it is necessary to comprehend the connection. Then, we can recognize the significant role of alphabetic structure for understanding the gist of pronunciation exercise. This paper is classified into four parts. Each part consists of the material to affirm the fact that writing system should be the inevitable equivalent of sound system, and vice versa. In the first section I show that the development of the way of pronouncing English words is closely related with the endeavors of the scholars. While performing the survey of the studies about the alphabetic structure of the age many scholars found that the spelling construction was recorded without any common denominator. Thus, they not only sought to stage the bedrock for the standard written form of words but also to associate the alphabet letters with phonetic features. Secondly I mention the negative aspect of the 'only spelling based English pronunciation education' for the educational goal of 'Phonics methodology.' In this part I suggest the essentiality of phonemic properties with the phonetic prospect: phonemic awareness. Thirdly I refer to the standardization of the spelling system of English. As the realm of application of the language is extended toward the various professional areas such as commercial, scientific, and cultural spheres, it is quite natural to assume that the usage of the language will be transformed according to the areas in the world. Fourthly I introduce the first English-Korean grammar book with the section of 'the introduction to English pronunciation.' At the chapter the author explained the sound features of English based on the regulation of 'Scientific Alphabet' of U.S.A. In the transcribing system all the symbols were postulated on the basis of the English alphabet form instead of the separate phonetic signs of IPA.

• The Journal of Korean Medical History
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• v.26 no.2
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• pp.111-122
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• 2013

Korean medical journals were continuously published during the period of Japanese colonization of Korea. Various advertisements by herbal drugs manufacturers were in these journals, targeting Korean medical doctors or students who aspired to be Korean medical doctors. The advertisements varied from small ones to large-scale ads. At first these advertisements covered only dried herbs, but with time, they came to advertise various kinds of drugs. Advertisement of merchandise drugs brought many changes to the medical culture of Korea. Korean medical doctors who only prescribed dried herbs before began to prescribe merchandise drugs as well. When treating patients, they not only used Korean drugs but also actively prescribed merchandise drugs and western drugs, showing an advancement in treatment. As Korean medical doctors played the role of providers of merchandise drugs, herbal drugs manufacturers and Korean medical doctors seemed as sellers and consumers on the surface. However, they maintained a relationship where Korean medicine worked as the common denominator. Among merchandise drugs, Yoeng-so-hwan, Bi-jeon-go, and Myeol-dok-hwan were advertised often, and this shows that people at the time suffered mostly from digestive diseases, skin diseases, and sexually transmitted diseases. Herbal drugs manufacturers were business managers whose main objective was to make a good profit, but they consisted a part of Korean medical society. Like Korean medical doctors, they were anxious about the fall of Korean medicine. As a part of popularization of Korean medicine, they encouraged Korean medical doctors to treat patients using herbal drugs and merchandise drugs. This thought was reflected well in advertisements and Korean medical doctors made use of this thought well.

• Journal of architectural history
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• v.25 no.2
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• pp.57-68
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• 2016

This study explored the Jeollajwasuyeong Dongheon in the Late Joseon dynasty and its findings are as follows. Buildings in Jeollajwasuyeong were completed since the mid-18th century. They formed areas based on functions and were largely classified into two areas. The buildings within Yeongseong included Gaeksa (guesthouse), Dongheon(government office), Hyangcheong(advisory organ), Jungyeong(military camp), Guncheong (county office), Gongbang(workroom), and Changgo(warehouse). There were also buildings for low-ranking government officials. The central part of Jeollajwasuyeong was the areas of Gaeksa and Dongheon. Gaeksa was iconic area where local governors served King and had 75 Jinnamgwan Guesthouses and 3 inner gates. Those were measured off by separate walls. The Dongheon area was located in the northeast of Gaeksa. There were three gates such as Wanyeongru, Gongsamun, and Jeongbyeonmun at the entry area, which were also divided by walls like Gaeksa. Unjuheon (Dongheon) was at the center of the area where Gyeolseungdang, Mugwonjae, Naea, Chaekbang, and Gongsu were built. Outside the area, Baekwadang(used as Bijangcheong), Jinhyulgo, and Byeonggo were composed of part of the Dongheon area. Most of the buildings in Dongheon seemed to be repaired since 1664. It was difficult to locate the area of previous Dongheon. In particular, Jinnamgwan was first built in 1599 and destroyed by fire in 1716. In 1718, the building was reconstructed and shared historic denominator with Unjuheon before 1858 and reconstructed Unjuheon in 1869. It was found that Unjuheon was reconstructed more than at least three times, which was the central building in Dongheon. The buildings including Gyeolseungdang, Mugwonjae, and Baekwadang in the area were not existed within Jeollajwasuyeong and were reconstructed more than once and maintained until the early 1900s.