• Journal of Korean Society of Forest Science
• /
• v.107 no.1
• /
• pp.16-24
• /
• 2018

This study was investigated to select superior population and clones of Salix gracilistyla for promoting woody biomass resources through creating of short rotation coppices (SRC). Plant materials were collected from seven different population groups of S. gracilistyla and planted at two different nursery sites in Chuncheon and Yongin. Height and root collar diameter showed statistically significant differeces among population, nursery, and annual growth for three years (p<0.01). Aboveground biomass was harvested to investigate dry weight after 3 years from planting, the Youngwol population showed the highest yield as $4.8kg\;DW\;plant^{-1}$ in Chuncheon nursery which was more than double yield compared to the other nursery planted plants. However, Hongcheon and Wonju populations as $3.3kg\;plant^{-1}$, showed the best yield in Yongin nursery. In addition, there was a significant difference between collected populations and nurseries. But there was statistically significant different interaction between population (Pop) and nursery (Nur) (F value = 3.51, p<0.01). Therefore, the superior populations selected by this experiment could be cultivated as an excellent variety for woody biomass resources through the clonal test.

• Journal of Yeungnam Medical Science
• /
• v.10 no.2
• /
• pp.338-344
• /
• 1993

The purpose of this study was to investigate the trait cortical arousal level, measured by extraversion-introversion, in schizophrenics. Subjects in this study were 231 (chronic schizophrenics=78, acute schizophrenics=62, and normal persons=91). All subjects were asked to respond to extraversion-introversion subtest scale in the korean EPQ(Korean Version Eysenck Personality Questionnaire). Collected data were analyzed by using the t-test and one-way analysis of variance. Results were as follows : 1) Trait cortical arousal level of chronic schizophrenics, which was measured by extraversion-introversion subtest scale in the Korean EPQ, was statistically higher than that of acute schizophrenics and normals. 2) Acute schizophrenics and normals were not significantly different in the trait cortical arousal level. However, the trait cortical arousal level of chronic schizophrenics was higher than that of acute schizophrenics. Therefore, it may state that the trait cortical arousal level of schizophrenics is getting higher when schizophrenic symptoms become more chronic.

• Korean Journal of Plant Taxonomy
• /
• v.43 no.4
• /
• pp.245-251
• /
• 2013

Paeonia lactiflora is a valuable natural resource for horticulture and traditional Chinese medicine. To propose conservation strategy and future utility of the wild Paeonia lactiflora populations recently found around the Gyeongju National Park, genetic diversity analysis using microsatellite markers were performed. Three populations in and near the Gyeongju N.P. and one population from Jilin, China were analyzed for five microsatellite markers, producing 61 alleles with mean observed heterozygosity($H_o$) of 0.452. $F_{ST}$ value (0.11642) suggested moderate level of genetic differentiation among the populations, and hierarchical AMOVA suggested most of the genetic variation resides within/among the individuals rather than among-population. While AMOVA with $F_{ST}$ suggested lack of genetic differentiation between the regional (Korean vs. Chinese) populations, AMOVA with $R_{ST}$, which incorporates the allele sizes, suggested considerable differentiation between them, but without significant statistical support. STRUCTURE analysis also suggested segregation of regional populations with presence of gene flow among the three Gyeongju N.P. populations. Considering small population size and scarcity of mature individuals, further protection and long-term monitoring are needed.

• Journal of Science Education
• /
• v.41 no.2
• /
• pp.195-212
• /
• 2017

Small group learning is an educational approach to allow students to solve the problems and to achieve a common goal. Especially, small group learning in science education is one of the most important educational approaches and effective to ensure understanding of a topic. Small group learning consisting of three students in science education maximize student understanding and learning efficiency. However, It is reported that the effects of small group learning on achievement show different results, corresponding to different grouping methods(homogeneous/heterogeneous). This study investigated the effects of grouping method on difference of ecological niche of photosynthesis concepts. To achieve this, 1107 7th students were composed of homogeneous and heterogeneous groups classified into top, middle, and bottom levels. The photosynthesis units were divided into four categories: the photosynthesizing place, the substances of photosynthesis, required materials for the photosynthesizing, and environmental factors affecting photosynthesis. A questionnaire was composed by selecting concepts having a frequency of 4% or more based on prior studies on the change of the ecological status of photosynthesis. The questionnaire was scored in terms of relativity and understanding on each of the proposed concepts in the four categories. The result of this study is as set forth below. 1) There was an enhancement of learning the concept of science in small group classes consisting of 3 students. 2) To enhance the average upon composing of a group, it is proposed that the group should be formed homogeneously, and to reduce the deviation between the members, it is proposed that the group should be formed heterogeneously. Through this study, it is expected that specific studies verifying the difference or effect on the duplicity of results are conducted based on the composition of groups.

• Journal of Elementary Mathematics Education in Korea
• /
• v.14 no.3
• /
• pp.907-935
• /
• 2010

The purpose of this study was to investigate the effects of using open-ended problems in ability-level activities in mathematics instruction and to draw some informative conclusions in order to improve the practice of teaching and learning mathematics in the elementary school. To fulfill the purpose, the research questions were established as follows: 1. Is there any difference between the academic achievements of the experimental group(doing ability-level activities using open-ended problems) and the control group(doing general ability-level activities)? 2. Which sub-group(grouped by achievement score in pretest) get affected most by ability-level activities using open-ended problem in the experimental group? 3. What kinds of responses do students show in their ability-level activities using open-ended problems? By applying t-test and analysing the response, the conclusions were drawn as follows: First, using open-ended problems in ability-level activities has positive effects on the academic achievement of the experiment group. The mean of posttest scores of the experiment group was statistically meaningfully higher(p<.05). Second, using open-ended problems in ability-level activities affect most to the achievement of lower sub-group in the experiment group. The mean of posttest scores of lower sub-group in the experiment group was statistically meaningfully higher than that of control group(p<.05). Third, students showed various and creative response in their ability-level activities using open-ended problems.

• Journal of Life Science
• /
• v.21 no.7
• /
• pp.1025-1031
• /
• 2011

The purpose of this study was to analyze the effects of aerobic exercise and black garlic intake on blood lipids, lipid peroxidation and BAP in rats. The subjects for the study were 25 male Sprague-Dawley rats composed of the control group (CG, n=6), exercise group (EG, n=6), which trained for 4 weeks (30-60 min/day, speed at 15 m/min), black garlic intake group (BGG, n=7), and exercise with black garlic intake group (EBGG, n=6). Blood lipids, lipid peroxidation, and BAP were measured in all the subjects after the end of the 4 week treadmill exercise period. The findings of this study were as follows; TC and TG were significantly lower in the EBGG compared to other groups, while there were no significant findings for HDL-C and LDL-C levels. TBARS was significantly lower in the EBGG compared to the CG, and the BAP from the EBGG and EG were significantly higher than in the CG and BGG after 4 weeks of treadmill exercise. Therefore, aerobic exercise with black garlic intake was effective in improving TC, TG, TBARS, and BAP. Consequently, aerobic exercise with black garlic intake will be effective for activating antioxidant defenses and decreasing cardiovascular diseases.

• The Journal of the Korea Contents Association
• /
• v.12 no.9
• /
• pp.408-421
• /
• 2012

The purpose of this study was to verify differences in changes of physical self-concept between Taekwondo participation group and non Taekwondo participation group in order to meet the needs of the study the limitations of previous studies had to be considered. The participants were elementary students in S city selected by this researcher. 30 students were in the Taekwondo participation group and 40 students were in the non Taekwondo participation group decided by ACSM(15) exercise guide line standard, three times repetition measurements per 12 weeks were executed for $2{\times}3$ mixed design with repeated measure. For this statistic, SPSS 12.0 for windows was used for technical statistic, two-way ANOVA, paired t-test, and independent t-test. The results were as follows; First, there were differences of change pattern in physical self-concept generally between Taekwondo participation group and non Taekwondo participation group. Second, there was a difference between Taekwondo exercise group and non Taekwondo exercise group according to 1st and 2nd, 1st and 3rd measurement point partially. Third, there were differences between the Taekwondo exercise group and non Taekwondo exercise group on the 2nd and 3rd measurement. In conclusion, Taekwondo discipline tended to have a large effect increasing physical self-concept.

• Korean Journal of Plant Resources
• /
• v.23 no.4
• /
• pp.360-367
• /
• 2010

The genetic diversity and structure of P. tongkangensis in 5 populations from 3 regions was investigated using 56 markers derived from 6 ISSR primers. Genetic diversity at the species level (P=94.6, SI=0.377, h=0.240) was substantial considering the limited distribution and small size of populations. Genetic differentiation among regions (12%) and among populations (13%) in the region was not clearly evident, which suggested a moderate level of gene flow among adjacent populations. The Mantel test revealed a significant correlation between genetic differentiation (${\Phi}_{ST}$) and geographic distance among populations. This was supported by cluster analysis and principal coordinate analysis (PCoA). The significant difference in marker band frequency at many loci and their fixation in opposite directions in the smallest and most isolated population SC were considered due to genetic drift. Therefore, the genetic diversity of P. tongkangensis could be compromised if the distribution area or the size of the population was further reduced. In particular, small and isolated populations could be at great risk of extinction. Considering this, the unique habitats of P. tongkangensis should be protected and the reduction of population size should be closely monitored. Conservation efforts including the seeding and planting of seedlings should be done carefully based on their genetic and ecological traits. Our data support the argument that establishing an integrated management system for the efficient conservation of P. tongkangensis is critical.

• Korean Journal of Plant Resources
• /
• v.26 no.5
• /
• pp.619-627
• /
• 2013

Deutzia paniculata Nakai is a Korean endemic species that has a very restricted distribution in Gyeongsang-do, South Korea. The genetic diversity and structure of five populations of D. paniculata were investigated using 31 ISSR loci from six primers. The Shannon's index (0.429) and genetic diversity (0.271) were relatively higher than those of other rare plant species in Korea. The Miryang (MY) and Yangsan (YS) populations, which have higher flowering rates than the other populations, showed greater genetic diversity than the other populations. An analysis of the molecular variance (AMOVA) showed that 16% of the total variation could be attributed to differences among the populations, and 84% to the differences within populations, indicating moderate gene flow among adjacent populations. The high genetic diversity and low genetic differentiation in the Deutzia paniculata populations, which have a restricted distribution, is considered to be affected by outcrossing of the mating system and abundant individuals in the populations. These results suggest that ex situ conservation strategies are needed to sustain the current genetic diversity of D. paniculata.

• Journal of Digital Convergence
• /
• v.15 no.1
• /
• pp.485-495
• /
• 2017

This study looked into the effects of acceptance and commitment therapy(ACT) program on the premenstrual symptoms, attitudes toward menstruation and perceived stress, in females in their 20's suffering from premenstrual syndrome(PMS). Among the 263 students from 3~4 year universities, 21 were selected as participants. 7 were assigned to the acceptance and commitment therapy(ACT) group, 7 were assigned to the cognitive behavior therapy(CBT) group, and 7 were assigned to the control group. As a result, emotional factor from the premenstrual symptoms has significantly decreased more in the acceptance and commitment therapy(ACT) group, and the cognitive behavior therapy(CBT) group in comparison to the control group. In regards to attitudes toward menstruation, there were no statistical significance in the acceptance and commitment therapy(ACT) group, however there were positive changes, and the cognitive behavior therapy(CBT) group displayed significant change in the follow-up study. In perceived stress, acceptance and commitment therapy(ACT) group displayed more significant decrease than the control group and the cognitive behavior therapy(CBT) group, and that level remained unchanged until the follow-up study.