• The Journal of the Korea Contents Association
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• v.20 no.7
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• pp.282-291
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• 2020

This study was conducted to explore the effects of students' problem solving ability according to the level of structuring of curriculum tasks in PBL activities. The study was conducted on 60 college students in curriculum classes. Problem solving ability was measured at the beginning of the semester. And after the midterm exam, PBL activities were conducted. 30 experimental groups performed unstructured tasks. 30 comparison groups performed semi-structured problems. After the task was completed, problem solving ability was measured at the end of the semester. Collected data were analyzed using ANCOVA. As a result, it was verified that the experimental group had a statistically significant improvement in information collection, evaluation, and feedback level than the comparative group.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.75-82
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• 2017

In this paper, we consider social network analysis that focuses on community detection. Social networks embed community structure characteristics, i.e., a society can be partitioned into many social groups of individuals, with dense intra-group connections and much sparser inter-group connections. Exploring the community structure allows predicting as well as understanding individual's behaviors and interactions between people. In this paper, based on the interaction information extracted from a real-life Bluetooth contacts, we aim to reveal the social groups in a society of mobile carriers. Focusing on estimating the closeness of relationships between network entities through different similarity measurement methods, we introduce the clustering scheme to determine the underlying social structure. To evaluate our community detection method, we present the evaluation mechanism based on the basic properties of friendship.

• Korean journal of communication and information
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• v.48
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• pp.257-279
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• 2009

The purpose of the current study is to examine the structural relationship between communication competence and self-presentation through motivational perspectives. The present study hypothesized structural model to examine the effects of autonomy, relatedness, and life satisfaction along with communication competence on the self-presentation. We investigated how these effects were influenced by differences in the structural relationships of males and females. The data with the sample of 361 college students adequately fit to the hypothesized model. Through latent mean analysis, gender differences of the constructs were examined. The female students appeared to have higher levels of relatedness than the male students. The results showed that autonomy and relatedness are important factors to self-presentation mediating communication competence.

• Journal of the Korean earth science society
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• v.35 no.4
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• pp.267-276
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• 2014

The purpose of this study is to investigate the effects of problem-solving inquiry teaching using concept sketches on conceptual changes about plate tectonics and science-related attitudes. The subjects of this study were two classes of second-year students of K high school located at Anseong in Gyeonggi Province. Before instruction, a conceptual test was conducted to survey student's preconceptions about plate tectonics. The control group took a traditional lesson, while the experimental group was applied to problem-solving inquiry teaching using concept sketches. After the inquiry instruction, TOSRA (Test of Science-Related Attitudes) was administered to find out changes in science-related attitudes of the two groups. The results of this study are as follows. The experimental group understood concepts of plate tectonics better than the control group, which means that problem-solving inquiry teaching using concept sketches was more effective in students' conceptual understanding. Science-related attitudes of the experimental group showed a significant change in the categories of 'normality of scientists', 'pleasure of science lessons', and 'interests on science as a hobby'. In conclusion, the instruction of problem-solving inquiry using concept sketches produced students' positive changes in conceptual understanding about plate tectonics and science-related attitudes.

• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.246-254
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• 1991

Genetic structure of a Pinus densiflora population consisting of two subpopulations on the north-and south-facing slopes of a mountain was studied by allozyme analysis. Allozyme variants in aspartate aminotransferase(AAT), glutmate dehydrogenase(GDH) and leucine aminopeptidase(LAP) systems are encoded, at least, by eight loci ; five for AAT, one for GDH and two for LAP. Average number of alleles examined over six loci was 3.33. Average heterozygosity and genetic diversity computed over six loci were, respectively, 0.19 and 2.76 for parental population, 0.17 and 2.22 for progeny population. Differences in allelic frequencies between maternal sources at many of the investigated loci were found and between subpopulations on the north- and south-facing slopes. Allele frequencies of maternal origin at some of the loci were significantly different from each other between the two subpopulations. Thus it appears that the matings within and between subpopulations were not random and the mountain ridge that divides the north-and south-facing slopes isolate the two suhpopulations reproductively to a great extent. Some of the genotypes both in parental and progeny(embryo) groups deviate significantly from the Hardy-Weinberg equilibrium state. It appears from the result that the pine population is originated from a few limited ancestral trees and thus consanguineous matings are prevalent in this pine population.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.173-178
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• 1998

Twelve Camellia sinensis populations were studied to investigate the biomass distribution related to stand structure. With increasing mean age of the population, mean root collar diameter increased, while mean height, density and root collar area had no correlation with the age. The result of dimension analysis after cutting the sample trees showed that dry weights of stems +branches and root were exponentially increased and dry weights of current leaves and twigs were linearly increased with increasing root collar diameter. However, the dry weight of older leaves was not related to the root collar diameter. The range of total biomass was 1,162~11,474kg/ha and the range of current leaf biomass was 165~1,341kg/ha. The range of T/R ratio was 1.5~2.8. The biomass of stems+branches and root were significantly correlated with the root collar area of the population and were not significantly correlated with the mean age, mean root collar diameter and density of the population. The biomass of current leaves and twigs were significantly correlated with the root collar area and density of the population.

• Journal of Korean Home Economics Education Association
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• v.26 no.1
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• pp.17-30
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• 2014

This study examined the effect of middle school students' perceived marital conflict on the middle school students' aggression. Also it examined the differences of male and female middle school students. The researcher surveyed 500 questionnaires for middle school students and was using 444 questionnaires in the final analysis. To analysis the data, t-test, Pearson correlation and the multiple group Structural Equation Modeling approach was used. It was sown that in the middle school students who highly perceived their interparental conflict, the higher the aggression. Interpartental conflicts significantly affected on middle school students' aggression in male and female students. It was sown, also that in the male middle school students who highly perceived their interparental conflict than girl students who highly perceived, the higher the aggression. In conclusion, this study demonstrates the importance of parental roles have effects on middle school students' problem behavior. Especially it was found that male middle school students aggression are influences by interparental conflict. Accordingly, this study has significances by proposing methods of efficient parental consultation and education to resolve parental conflicts.

• Journal of Life Science
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• v.20 no.8
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• pp.1151-1158
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• 2010

The genetic diversity and population structures of fourteen Carex okamotoi (Cyperaceae) populations in Korea were determined using genetic variation at 25 allozyme loci. The Carex okamotoi species is native to Korea. It is endemic to three mountains (Mt. Taeback, Mt. Sobak, and Mt. Noreong) where it is found at 700~1,500 m above sea level. The percentage of polymorphic loci was 40.0%. Genetic diversity at the species level and at the population level was low ($H_{ES}$=0.106; $H_{EP}$=0.094), and the extent of the population divergence was relatively low ($G_{ST}$=0.082). Measurement of deviation from random mating ($F_{IS}$) within the 14 populations was 0.238. An indirect estimate of the number of migrants per generation was 2.78 (Nm=2.78). Analysis of fixation indices revealed a substantial heterozygosity deficiency in some populations and at some loci. Mean genetic identity between populations was 0.986.

• Journal of Digital Convergence
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• v.15 no.1
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• pp.603-610
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• 2017

The purpose of this study aimed to analyze the difference of the Sasang constitution type in the relationship between university life stress and mental stress. The data were collected by a self-reported questionnaire from 389 university students and 389 students were classified by QSCC II.(136 So-Eum, 139 So-Yang, 114 Tae-Eum). Multi-group analysis was performed to analyze the differences in the effects of university life stress on mental health according to the type of sasang constitution. Multi-group analysis was performed to analyze the differences in the effects of university life stress on mental health according to the type of sasang constitution. According to multi-group analysis, there were statistically significant differences in the effects of university life stress on mental health across So-Eum-So-Yang, Tae-Eum-So-Yang. Based on these results, a differentiated intervention plan suitable for sasang constitution was proposed.

• Journal of Life Science
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• v.16 no.1
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• pp.64-70
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• 2006

Starch gel electrophoresis was used to estimate genetic diversity and population structure of Pyrola fauriena H. Andr. in Korea. The percentage of polymorphic loci within enzymes was $57.1\%$. The values of genetic diversity at the species level and at the population were higher than average values for herbaceous with similar life history traits (Hes : 0.149; Hep = 0.134, respectively), whereas the extent of the population divergence was relatively low $(G_{ST}=0.082)$. $F_{IS}$, a measure of the deviation from random mating within the 12 populations, was 0.298. An indirect estimate of the number of migrants per, generation (Nm = 2.81) indicates that gene flow is moderate among Korean populations of the species. Analysis of fixation indices revealed a substantial heterozygosity deficiency in some populations and at some loci. This indicates that some populations sampled may have been substructured largely due to rhizotamous spread and decrease of population sizes.