• 충청수학회지
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• 제23권4호
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• pp.699-704
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• 2010

In this paper, we prove that the Hilbert 2-class field tower of an imaginary quadratic function field $F=k({\sqrt{D})$ is infinite if $r_2({\mathcal{C}}(F))=4$ and exactly one monic irreducible divisor of D is of odd degree, except for one type of $R{\acute{e}}dei$ matrix of F. We also compute the density of such imaginary quadratic function fields F.

• 대한음성학회:학술대회논문집
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• 대한음성학회 1996년도 10월 학술대회지
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• pp.464-467
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• 1996

This paper aims to exploit inter/intra-speaker phoneme sub-class variations as criteria for adaptation in a phoneme recognition system based on a novel neural network architecture. Using a subcluster neural network design based on the One-Class-in-One-Network (OCON) feed forward subnets, similar to those proposed by Kung (2) and Jou (1), joined by a common front-end layer. the idea is to adapt only the neurons within the common front-end layer of the network. Consequently resulting in an adaptation which can be concentrated primarily on the speakers vocal characteristics. Since the adaptation occurs in an area common to all classes, convergence on a single class will improve the recognition of the remaining classes in the network. Results show that adaptation towards a phoneme, in the vowel sub-class, for speakers MDABO and MWBTO Improve the recognition of remaining vowel sub-class phonemes from the same speaker

• Educational Technology International
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• 제16권1호
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• pp.31-57
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• 2015

This study aims to understand the overall experiences of students who use notebook computers in class by using a qualitative approach. Interview data were collected from 23 Korean college students at a Korean university, who use notebook computers in their classes; the data were analyzed through the constant comparison method. The results from this study can be categorized into two themes: the positive and negative effects of using a notebook computer in class, and different perspectives on the effects of using a notebook computer in class. The positive effects of notebook computer usage were specified as production of lecture notes, performing searches for information, management of learning materials, and effective time management. However, behaviors such as perusing other works not associated with the class were indicated as negative effects. The participants had different perceptions about the effect of notebook computer usage in increasing academic performance, although they were satisfied in their experience with notebook computers in general. These results imply that appropriate methods of technology usage are needed and that the support of an instructor is essential to achieve fully beneficial use of notebook computers in class.

• 아동학회지
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• 제22권4호
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• pp.201-212
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• 2001

The purpose of this study was to analyze toddlers' verbal and nonverbal interaction with their peers and caregivers according to the class size of child care centers in Seoul. The subjects of this study were 20, two-year-old(M=32.5 month) toddlers with peers and caregivers from child care centers in different class sizes, but with same caregiver-toddler ratio. Verbal and nonverbal interactions were videotaped during one hour indoor free play per child in the center. According to the class size, the results were as follows : 1) Toddlers in the small class played more cooperatively with peers, and uttered more regulative or directive words than those in the large class. 2) Toddlers in the large class were more aggressive than those in the small class. 3) Caregivers in small class expressed more empathetic behaviors to a toddler than those in large class.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권6호
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• pp.287-290
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• 2006

A class-E CMOS RF(Radio frequency) power amplifier with a 1.8 Volt power supply is designed using $0.25{\mu}m$ standard CMOS technology. To drive the class-E power amplifier, a Class-F RF power amplifier is used and the reliability characteristics are studied with a class-E load network. After one year of operating the power amplifier with an RF choke, the PAE(Power Added Efficiency) decreases from 60% to 47% and the output power decreases 29%. However, when a finite DC-feed inductor is used with the load, the PAE decreases from 60% to 53% and the output power decreases only 19%. The simulated results demonstrate that the class-E power amplifier with a finite DC-feed inductor exhibits superior reliability characteristics.

• 한국가정과교육학회지
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• 제10권2호
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• pp.13-28
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• 1998

The purpose of this study is to compare of learning effects between the inquiry training model and traditional lecture method in the unit of food and nutrition of home economics in the middle school and propose a teaching-learning method of home economics in the middle school.For this study I sampled one hundred students both male and female who were in the first grade students of middle school in Ansan city.The students were divided into two groups each of which was composed of one male class and one female class. One was called the inquiry training model group, which was taught by the inquiry training model, the other the traditional lecture method group, which was taught by traditional lecture method .They learned about food and nutrition unit during the same time. To evaluate the effectiveness of learning, learning achievement degree, instruction interest degree, and the powers of exploration process, a creativity lest by using a Questionnaire was gIven.The resuits of this study are as follows: 1. In the traditional lecture method group between the inquiry training model one, the difference of learning achievement degree was not significant. The score of learning achieve ment degree in the inquiry training group, the female class got higher scores than .the maleone, but the difference was not significant. 2. In the test of instruction interest degree, the traditional lecture method group got higher scores than the inquiry training model one. (p<.001.). In the inquiry training group the male class got higher scores than the f ema Ie one. (p < .001 ) 3. In the test of powers of exploration process, the traditional lecture method group got higher scores than the inquiry training model one.( p< .00 1). In the inquiry training group, the male class got higher scores than the female one, but the difference was not significant. 4. In the test of creativity, the traditional lecture method group got higher scores than the inquiry training one. (p < .00 1). In the inquiry training group, the female class got higher scores than the male one, but the difference was not significant Therefore, the inquiry training model is the more effective instruction model for both male and female students, rather than the traditional lecture method for instruction interest de¬gree, powers of exploration process, creativity and extends instruction interest degree for the male studentsale students.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제5권2호
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• pp.87-98
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• 2001

The Center for Science Gifted Education (CSGE) of Chongju National University of Education was established in 1998 with the financial support of the Korea. Science & Engineering Foundation (KOSEF). In fact, we had prepared mathematics and science gifted education program beginning in 1997. It was possible due to the commitment of faculty members with an interest in gifted education. Now we have 5 classes in Mathematics, two of which are fundamental, one of which is a strengthened second-grade class gifted elementary school students, and one a fundamental class, and one a strengthened class for gifted middle school students in Chungbuk province. Each class consists of 16 students selected by a rigorous examination and filtering process. Also we have a mentoring system for particularly gifted students in mathematics. We have a number of programs for Super-Saturday, Summer School, Winter School, and Mathematics and Science Gifted Camp. Each program is suitable for 90 or 180 minutes of class time. The types of tasks developed can be divided into experimental, group discussion, open-ended problem solving, and exposition and problem solving tasks. Levels of the tasks developed for talented elementary students in mathematics can be further divided into grade 5 and under, grade 6, and grade 7 and over. Types of the tasks developed can be divided into experimental, group discussion, open-ended problem solving, and exposition and problem solving task. Also levels of the tasks developed for talented elementary students in mathematics can be divided into the level of lower than grade 5, level of grade 6, and level of more than grade 7. Three tasks developed and practiced are reported in this article.

• 대한가정학회지
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• 제30권3호
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• pp.177-191
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• 1992

This study investigated how different relationships the family has with its social networks by social class. Among research families' primary social networks, the wife's relatives are the most, the neighbor the second, the husband's relative the third, and the church (or other religious groups) the fourth. Social class does not make any difference in what social network is the family's primary social network. When the husband or the wife participates in a social network, he or she tends to participate alone without his or her spouse. When the husband's educational level is high, the wife tends to participate in her alumni association alone. When the husband is in a professional or a white-collar occupation, he is likely to socialize with his work associates alone. On the contrary, when the family income gets high, the husband tends to bring his wife to his alumni association. When looking for a job, most husbands and wives do not resort to a social network for help. Lower-class people are more likely to obtain jobs through their social networks compared to higher-class people. That is, the lower one's educational levle, one's occupational status, or the family income is, the more likely one gets help from some social networks in searching jobs.

• 대한임베디드공학회논문지
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• 제10권5호
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• pp.325-333
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• 2015

Vision based night-time vehicle detection has been an emerging research field in various advanced driver assistance systems(ADAS) and automotive vehicle as well as automatic head-lamp control. In this paper, we propose night-time vehicle detection method based on multi-class support vector machine(SVM) that consists of thresholding, labeling, feature extraction, and multi-class SVM. Vehicle light candidate blobs are extracted by local mean based thresholding following by labeling process. Seven geometric and stochastic features are extracted from each candidate through the feature extraction step. Each candidate blob is classified into vehicle light or not by multi-class SVM. Four different multi-class SVM including one-against-all(OAA), one-against-one(OAO), top-down tree structured and bottom-up tree structured SVM classifiers are implemented and evaluated in terms of vehicle detection performances. Through the simulations tested on road video sequences, we prove that top-down tree structured and bottom-up tree structured SVM have relatively better performances than the others.

• Kyungpook Mathematical Journal
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• 제56권1호
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• pp.121-123
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• 2016

In this paper, we compute the number of distinct centralizers and commutativity degree of a class of finite groups. These computations produce a further class of examples of groups answering one question raised by Belcastro and Sherman and another one raised by Lescot.