• Honam Mathematical Journal
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• v.10 no.1
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• pp.23-30
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• 1988

Let C[C, D] and $S^{*}[C,\;D]$ denote the classes of functions g, g(0)=1-g'(0)0=0, analytic in the unit disc E such that $\frac{(zg{\prime}(z)){\prime}}{g{\prime}(z)}$ and $\frac{zg{\prime}(z)}{g(z)}$ are subordinate to $\frac{1+Cz}{1+Dz{\prime}}$ $z{\in}E$, respectively. In this paper, the classes K[A,B;C,D] and $C^{*}[A,B;C,D]$, $-1{\leq}B<A{\leq}1$; $-1{\leq}D<C{\leq}1$, are defined. The functions in these classes are close-to-convex. Using the properties of convolution operators, we deal with some problems for our classes.

• Genomics & Informatics
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• v.8 no.4
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• pp.170-176
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• 2010

The Ribonucleotide reductases (RNR) are essential enzymes that catalyze the conversion of nucleotides to deoxynucleotides in DNA replication and repair in all living organisms. The RNRs operate by a free radical mechanism but differ in the composition of subunit, cofactor required and regulation by allostery. Based on these differences the RNRs are classified into three classesclass I, class II and class III which depend on oxygen, adenosylcobalamin and S-adenosylmethionine with an iron sulfur cluster respectively for radical generation. In this article thirty seven sequences belonging to each of the three classes of RNR were analyzed by using various tools of bioinformatics. Phylogenetic analysis, dot-plot comparisons and motif analysis was done to identify a number of differences in the three classes of RNRs. In this research article, we have attempted to decipher evolutionary relationship between the three classes of RNR by using bioinformatics approach.

• Proceedings of the KSPS conference
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• 2004.05a
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• pp.251-255
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• 2004

The purpose of this paper is to examine the effect of using songs for the acquisition of English Prosody in elementary school. For the purpose, 8 classes were chosen to teach songs for four months, and listening tests and reading test were performed for analyzing the effect. The result is as follows : (1) The result of listening test showed that the average scores of the experimental classes were higher than those of comparative classes, and it was more effective in lower grades than in upper grades. (2) In pronunciation tests, the pronunciations of experimental classes were more similar to native speaker's pronunciation that those of comparative classes in intonation, lexical stress and sentence stress. (3) Singing songs repeatedly is more important than learning many songs. It means that to give the chances to sing as many times as possible is advisable for teaching pronunciation.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.2
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• pp.29-40
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• 2005

In this research, we propose packet scheduling algorithm considering different QoS characteristics of real-time traffic and non-real-time traffic in the next generation wireless communication system serving the multimedia traffic and a new efficient framing method cooperated with this packet scheduler. When the selected traffic classes of the selected users are transmitted, our proposed framing method can increase the number of serviced traffic classes by mixing the many different traffic classes within one frame considering data rate decided by the allocated AMC (Adaptive Modulation and Coding) option. Using this proposed method, the fairness among the traffic classes can be achieved and the system performance for total throughput and delay can be enhanced. Simulations are performed to analyze the performance of the proposed framing method. Our proposed packet scheduler and framing method will be applied to the next generation multimedia wireless communication system serving many traffic classes.

• Journal of applied mathematics & informatics
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• v.6 no.2
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• pp.433-446
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• 1999

Let G denote either of the groups $GL_2(q)$ or $SL_2(q)$. The mapping $theta$ sending a matrix to its transpose-inverse is an auto-mophism of G and therefore we can form the group $G^+$ = G.<$theta$>. In this paper conjugacy classes of elements in $G^+$ -G are found. These classes are closely related to the congruence classes of invert-ible matrices in G.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.8
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• pp.990-1000
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• 1998

The purpose of this study is to find out the relationship between consumer's economic environments and clothing buying behaviors. Consumer's economical environments can be identified as the influence of IMF and subjective social classes. And clothing buying behavior can be defined such as clothing buying motives, informants, clothing selective standards, price, patronage store in terms of consumer decision making process. This study was carried out in theoretical and empirical ways. The questionnaire was administered to 375 university students living in seoul during the April, 1998. The results of empirical study were as follows; First, Consumer's individual characteristics are proven to be significantly related to the influence of IMF and subjective social classes. Second, the influence of IMF is proven to be significantly correlated to the clothing buying behavior. Third, the subjective social classes is proven to be partially related to the clothing buying behavior.

• The Journal of Korean Society for School & Community Health Education
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• v.1 no.2
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• pp.1-16
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• 2000

Objectives: The purpose of this research is to identify and understand sexuality in 10th grade co-ed students in Seoul, Korea in order to construct practical curriculum for sex education for youth. Method: One-hour class per week was done to the 3 classes among 6 classes for Spring semester in 1999: small group discussion(for 3 classes) & questionnaires(6 classes) were taken. Results: Despite the increased number of sex education programs, peers apparently remain the major source of information and the counselor of their sexual problems. The rate of correct answer of the sex knowledge is still low, especially on biological aspects of opposite sex. Western culture and women's movements have changed our society. In turn, sexual sterotypes and roles have been changing. Small group discussions were taken after the classes of pregnancy, abortion and unmarried parents. Their opinions on maintaining virginity were collected. The condition of choosing spouse and boy/girl friend is quite different in many aspects.

• Korean Journal of Remote Sensing
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• v.20 no.5
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• pp.353-359
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• 2004

This study proposes an approach to unsupervisedly estimate the number of classes and the parameters of defining the classes in order to train the classifier. In the proposed method, the image is segmented using a spatial region growing based on hierarchical clustering, and fuzzy training is then employed to find the sample classes that well represent the ground truth. For cluster validation, this approach iteratively estimates the class-parameters in the fuzzy training for the sample classes and continuously computes the log-likelihood ratio of two consecutive class-numbers. The maximum ratio rule is applied to determine the optimal number of classes. The experimental results show that the new scheme proposed in this study could be used to select the regions with different characteristics existed on the scene of observed image as an alternative of field survey that is so expensive.

• Journal of Engineering Education Research
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• v.24 no.4
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• pp.52-60
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• 2021

This study designed and developed a class using review games as a way to enhance students' interest, class participation, and class comprehension in engineering theory classes, and explored their educational effectiveness. To this end, a review game strategy based on the Creative Training Technique was established and applied to three engineering theory subjects. The types of review games include Jin-jin-ga, Bingo, Challenge Golden Bell, Finding hidden terms, and Completing initial sentences. As a result of applying this review game strategy to the classes over the past decade, students' satisfaction and lecture evaluation scores significantly increased compared to before application, and it was confirmed that students' interest in and understanding of the class increased significantly. Furthermore, this gamification class strategy can be a way to increase students' participation in theory classes regardless of their major, and can be applied to non-face-to-face online classes.

• Journal of The Korean Association For Science Education
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• v.25 no.7
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• pp.794-800
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• 2005

The purpose of this study was to examine the state of management and science teachers perception of science classes and clubs in secondary schools. There ware 125 participants (75 middle school teachers and 50 high school teachers) from eight metropolitan cities and local areas, and more than 80% of the participants had managed science classes or clubs. Results found that a significant number of science teachers felt it necessary to manage science classes and/or clubs in secondary schools. They believed the classes and/or clubs to be beneficial in the activation of students' interest in science, even though they might not be effective ways of improving scientific achievement. In addition, it was found that secondary science teachers desire financial support, in-service programs, and efficacious programs supporting science class and club management.