• Journal of Periodontal and Implant Science
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• v.26 no.3
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• pp.725-734
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• 1996

The present study has been performed to revise the forms of early-onset periodontitis(EOP) into the homogeneous phenotypic subsets by cluster analysis using sets of clinical parameters. Retrospective radiographic interproximal alveolar bone levels were measured from cemento-enamel junctions on patients who have previously been diagnosed as having one of EOP during last 5 years. Mean interproximal bone levels(BL) and mesial bone level(Ratio) of 1st molars relative to mean interproximal bone levels of adjacent teeth(lst and 2nd premolars and canines)were calculated on each patient. Using parameters BL and Ratio(BR group) or BL, Ratio and age(BRA group), cluster analysis was performed to revise EOP patients into homogeneous subsets. At least three or four cluster could be homogeneously formed both in BR or BRA groups with statistically significant differences in parameters used among clusters as evidenced by MANOVA test. It was shown that the greater the BL, the smaller the Ratio was. It was also evident that mean interproximal bone levels were lowest aroud 1st molars and/or incisors regardless of cluster types. The results has provided cluster-based studies for identifying laboratory markers responsible for the development of EOP subsets.

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.1002-1009
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• 2007

A rapid, convenient homogeneous competitive enzyme immunoassay for estimating the amount of fenthion is described. The assay utilizes glucose-6-phosphate dehydrogenase-hapten conjugates that are inhibited in solution by antibodies obtained from bovine serum albumin-hapten conjugates. In order to investigate the effects of bridging group recognition on the sensitivity of dose response characteristics, the bridging groups of varying alkyl chain length were attached at the phosphate position of fenthion. Among the antibodies used, the one obtained from the use of hapten (fenthion analog) with the same bridging group structure that was used in preparing the enzyme-fenthion conjugates showed maximum inhibition (up to 51.8%) in the absence of fenthion. In the presence of fenthion, the activity of the enzyme-hapten conjugate is regained in an amount proportional to the fenthion concentration. Under the optimized condition, the $ED_{50}$ value for fenthion was $0.809{\mu}g/ml$. The assay developed in this study is a rapid effective screening method for fenthion prior to precise analysis.

• The Korean Journal of Ceramics
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• v.5 no.3
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• pp.265-269
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• 1999

Polyethylene was modified with silanol groups on its surface by photografting of vinyltrimethoxysilane in vapor phase by using benzophenon as a polymerization initiator and by hydrolyzing the methoxysilane groups into the silanol groups with HCI solution. The modified polyethylene formed a dense and homogeneous apatite layer on its surface in a solution with ion concentrations 1.5 times those of human blood plasma within 21 days. This kind of biomimetic process could provide techniques for fabricating apatite-polymer composites with three dimensional structure analogous to the natural bone.

• Journal of Digital Convergence
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• v.17 no.12
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• pp.59-65
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• 2019

The purpose of this study is to investigate the effects of the learning environment on the learning achievement of the learners and to improve the learning achievement of the learners while accepting the fact that it is difficult to change the class environment in which the middle and large group. Among the learner's positive and cognitive factors, we examined the factors that can classify learners into homogeneous groups in programming learning. The difficulty level of the learning contents influenced factors that classify the homogeneous group, and the factors were analyzed by dividing the intermediate difficulty and the final achievement. In addition, we examined the factors that affect the difference between two grades in order to analyze factors affecting steady learning regardless of difficulty level. It was found that the learners' personal motivation influenced the learning achievement of easy learning contents, and the performance self - efficacy had influence on the learning achievement and achievement of difficult learning contents.

• Journal of the Korean earth science society
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• v.24 no.3
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• pp.141-149
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• 2003

This study investigated the effect of gender grouping on cooperative learning on the basis of student achievement and science-teaming attitude. Homogeneous and heterogeneous gender groupings were used in the treatment groups for the learning strategies of earth science. Traditional instruction was performed for the control group. Three classes at a middle school were assigned to the groups. Before the treatment instruction, a questionnaire about science-learning attitude was administered to 144 students, and their scores were utilized as covariate. Then, the same questionnaire was given with a test of science achievement designed in this study. The changes in both achievement and attitude among the three groups were analyzed statistically. Significant differences were not shown in science achievement or in the difference of gender with respect to perceptions about science. There were significant changes between the homogeneous and heterogeneous gender grouping in their attitudes toward science instruction. Here the cooperative learning group, regardless of the gender grouping, tends to exhibit more positive perceptions towards their learning environment than the control group, particularly in female students.

• Journal of The Korean Association For Science Education
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• v.28 no.1
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• pp.75-88
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• 2008

The purpose of this study was to understand the factors affecting interactions as well as the students' learning process in small group activities. For this purpose, the changes and characteristics of students' interactions in scientific inquiry experiments were analyzed. This study focused on 2 homogeneous small groups of eighth graders. Students were involved in 13 inquiry experiments for one year and students' interactions in each experiments were observed and recorded using video/audio and the data recorded were transcribed. The analysis of data was based on the method of making a note by looking on and listening to the data repeatedly. Changes in the interactions of the two homogeneous groups differ remarkably. In small group A, owing to the conflicts of students' emotions, learning through social interactions became to be impossible. On the other hand, the interactions in small group B became more active. It seems that this changes are affected largely by the existence of peers who are able to mediate different opinions or feelings among group members. In general, middle school students were poor at receiving peers' opinion, cared a lot about writing reports. The less able students tended to be placed at a disadvantageous position in experiment lessons emphasizing social interactions. Four factors that affected the change of interactions were identified: Is the aim of experiments the understanding or completion of report? Is there any attitude towards peers' suggestions? Is there a disposition to care about peers? Is there any peer to mediate on peers' opinions or feelings? Educational implications of the progression of activities emphasizing interactions and the organization of grouping were drawn.

• The Research Journal of the Costume Culture
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• v.8 no.3
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• pp.422-435
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• 2000

In this study female college students having high interest in fashion were selected by homogeneous purposive sampling. The students were classified into two groups. 301 Students living in Chinju were asked on self-actualization and design preference. The date of respondents were analyzed by Pearson's correlation coefficients and t-test. The results of this study can be summarized as follows. 1. The line preference, chroma, thickness and weight of clothing textile were different in these two groups. 2. The students of individuality had self-actualization, feeling reactivity, self-regard, existentiality and capacity of intimate contact. 3. There were significant relation between self-actualization and the preference for clothing form, color and texture in two groups.

• Journal of the Korean Mathematical Society
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• v.44 no.5
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• pp.1121-1137
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• 2007

There are 7 types of 4-dimensional solvable Lie groups of the form ${\mathbb{R}^3}\;{\times}_{\varphi}\;{\mathbb{R}}$ which are unimodular and of type (R). They will have left. invariant Riemannian metrics with maximal symmetries. Among them, three nilpotent groups $({\mathbb{R}^4},\;Nil^3\;{\times}\;{\mathbb{R}\;and\;Nil^4)$ are well known to have lattices. All the compact forms modeled on the remaining four solvable groups $Sol^3\;{\times}\;{\mathbb{R}},\;Sol_0^4,\;Sol_0^'4\;and\;Sol_{\lambda}^4$ are characterized: (1) $Sol^3\;{\times}\;{\mathbb{R}}$ has lattices. For each lattice, there are infra-solvmanifolds with holonomy groups 1, ${\mathbb{Z}}_2\;or\;{\mathbb{Z}}_4$. (2) Only some of $Sol_{\lambda}^4$, called $Sol_{m,n}^4$, have lattices with no non-trivial infra-solvmanifolds. (3) $Sol_0^{'4}$ does not have a lattice nor a compact form. (4) $Sol_0^4$ does not have a lattice, but has infinitely many compact forms. Thus the first Bieberbach theorem fails on $Sol_0^4$. This is the lowest dimensional such example. None of these compact forms has non-trivial infra-solvmanifolds.

• Journal of the Korean Chemical Society
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• v.47 no.5
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• pp.519-529
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• 2003

This study investigated the characteristics of verbal interactions of various small groups based on previous achievement in paired think-aloud problem solving. Two classes of a high school were assigned to the homogeneous and heterogeneous groups, and taught on chemistry. Students from homogeneous groups (high${\cdot}$high, mid？id) and heterogeneous groups (high${\cdot}$mid, high${\cdot}$low) were selected, and their algorithmic problem solving on chemical equation and stoichiometry were audio/video taped. In high${\cdot}$high group, solver's 'require agreement' and listener 'agree' were frequently exhibited. On the other hands, listener's 'point out' and solver's 'modify' were frequently exhibited in mid${\cdot}$mid group, which was also observed in the heterogeneous groups (high${\cdot}$mid, high${\cdot}$low). Many verbal interactions were analyzed to be in symmetrical type. In this type, 'require agreement-agree' of high${\cdot}$high group was the most frequent. 'problem solving-agree' of high${\cdot}$high group was the most frequent in the solver-dominant type, while 'point out-modify' of high${\cdot}$low group in the listener-dominant type. The verbal behaviors related to the solving stage were frequently observed, but there were few related to the reviewing stage.

• Journal of the Korean Mathematical Society
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• v.42 no.2
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• pp.365-386
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• 2005

Let L be the free Lie superalgebra generated by a $Z_2$-graded vector space V over C. Suppose that g is a Lie superalgebra gl(m, n) or q(n). We study the g-module structure on the kth homogeneous component Lk of L when V is the natural representation of g. We give the multiplicities of irreducible representations of g in Lk by using the character of Lk. The multiplicities are given in terms of the character values of irreducible (projective) representations of the symmetric groups.