• Korean Journal of Microbiology
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• v.52 no.1
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• pp.49-58
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• 2016

Compared to planktonic bacterial populations, biofilms have distinct bacterial community structures and play important ecological roles in various aquatic environments. Despite their ecological importance in nature, bacterial community structure and its succession during biofilm development in the Antarctic marine environment have not been elucidated. In this study, the succession of bacterial community, particularly during the early stage of biofilm development, in the Antarctic marine environment was investigated by pyrosequencing of the 16S rRNA gene. Overall bacterial distribution in biofilms differed considerably from surrounding seawater. Relative abundance of Gammaproteobacteria and Bacteroidetes which accounted for 78.9-88.3% of bacterial community changed drastically during biofilm succession. Gammaproteobacteria became more abundant with proceeding succession (75.7% on day 4) and decreased to 46.1% on day 7. The relative abundance of Bacteroidetes showed opposite trend to Gammaproteobacteria, decreasing from the early days to the intermediate days and becoming more abundant in the later days. There were striking differences in the composition of major OTUs (${\geq}1%$) among samples during the early stages of biofilm formation. Gammaproteobacterial species increased until day 4, while members of Bacteroidetes, the most dominant group on day 1, decreased until day 4 and then increased again. Interestingly, Pseudoalteromonas prydzensis was predominant, accounting for up to 67.4% of the biofilm bacterial community and indicating its important roles in the biofilm development.

• Journal of Plant Biology
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• v.28 no.1
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• pp.79-93
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• 1985

Plant succession and subsequent changes of soil properties were studied in sand bars at the Nagdong River estuary in Korea. By old maps, ages of sand bars such as Namusitdeung, Galmaegideung, Baeghapdeung and Ogryudeung were estimated about 10, 15, 25 and 60 years old, respectively. The dominance-diversity curves and plant species diversity indices among the sand bars showed increasing trend of stability from Galmaegideung toward Ogryudeung. The soil acidity, contents of organic matter and total nitrogen of soil increased significantly from Galmaegideung toward Ogryudeung. The order of successional degree among the sand bars on the basis of the number of plant species, the results of vegetation analysis and changes of soil properties almost coincide with the order of age among the sand bars. However, the order of successional degree between Namusitdeung and Galmaegideung was more or less obscured because of cyclic succession driven by allogenic processes.

• The Korean Journal of Ecology
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• v.18 no.1
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• pp.89-97
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• 1995

In order to study the successional trend and the heterogeneity of forest community, we investigated DBH frequency distribution of dominant tree species and the changes of several community indicies including ${\beta}-diversity\;({\beta}_t)$ along a belt transect in Mt. Yongam, Kwangnung Experimental Forest, which has been preserved for about 530 years. Quercus serrata, Carpinus laxiflora, and C. cordata were the three dominant species and their DBH frequency distribution showed a reverse J-shaped form, so these species seem to maintain by themselves. Dominancediversity curve had a lognormal distribution. d and H'for pooled quadrats were 0.13 and 1.09, respectively, but these indices within each quadiat varied with the range of 0.13 to 0.57 and 0.5 to 1.09, respectively. The value of ${\beta}_t$ along the belt transect ranged from 0.14 to 0.42. These results suggest that this forest community is in the stable climax stage but the components experience a heterogeneous microsuccession.

• Journal of Multimedia Information System
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• v.6 no.3
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• pp.147-154
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• 2019

In a variety of fields, highly developed technology is being combined to create a lot of value. In order to keep up with this global trend, the Ministry of Education, which is in charge of national education, continuously develops and applies content for creative education to textbooks. The continuous development of content for creative education is not only related to national interests, but also to the continued development of mankind. Today, the succession and development of human knowledge is in charge of the education system. Research into an effective educational system is necessary for effective succession of rapidly developing science and technology and building up technical personnel with such skills. In particular, the computer science field is faster in development than other scientific fields and has accumulated many technologies, indicating that it takes a lot of time and good teaching to foster talent that can effectively utilize the technology. In this paper, elementary school subjects were analyzed to achieve the purpose of cultivating talent in the field of computer science. In addition, we have investigated techniques related to computer programming learning not covered in elementary school subjects. So we developed content that students need to practice. Next, we taught the content to randomly selected elementary school students and assessed their educational effectiveness. As a result of training using the content we developed, 55.37% increased academic performance.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.201-207
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• 2022

This study analyzed the Seungmu research trends published in domestic academic journals from 1978 to 2021. Seungmu, a traditional Korean dance, has been handed down for a long time and has established itself as a traditional dance representing Korea. I think that the trend analysis of Seungmu Dance can present basic data that can solidify the succession, preservation and development of Seungmu Dance, a sustainable traditional cultural heritage. I think that the trend analysis of Seungmu dance is a meaningful process that lays the foundation for the vitalization and popularization of Korean traditional dance.

• Journal of Korean Society of Forest Science
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• v.109 no.3
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• pp.249-258
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• 2020

The purpose of this study examined the succession by vegetation type after forest ecosystem restoration in the Baramjae area. Vegetation of the Baramjae area was classified using a survey of 81 sites from May to October 2019. The vegetation type was classified as Pinus densiflora community group with both Quercus mongolica community and P. densiflora typical community. The group unit was further classified as the Quercus dentata typical subgroup, Salix koreensis subgroup, and Q. mongolica typical subgroup. Such as Q. mongolica, Quercus variavilis in vegetation unit 1, Q. mongolica, Q. dentata in vegetation unit 2, P. densiflora in vegetation unit 3 and S. koreensis in vegetation unit 4 were shown a high importance value. The difference in species by vertical layer is explained by sere. Based on the vegetation type classification system, Detrended Correspondence Analysis was conducted to observe the trend of succession. Since restoration, vegetation unit 1 and vegetation unit 2 were considered to have developed the most extensive vegetation. In vegetation unit 2 and vegetation unit 4, many of the species found were in the early vegetation development in S. koreensis subgroup. Accordingly, vegetation in the Baramjae area can be categorized as a stepwise succession.

• Journal of Ecology and Environment
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• v.44 no.4
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• pp.241-255
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• 2020

Background: The stem exclusion stage is a stage of forest development that is important for understanding the subsequent understory reinitiation stage and maturation stage during which horizontal heterogeneity is formed. Over the past 11 years (2009-2019), we observed a deciduous broad-leaved forest in the Albongbunji Basin in Ulleungdo, South Korea in its stem exclusion stage, where Fagus engleriana (Engler's beech) is the dominant species, thereby analyzing the changes in the structure (density and size distributions), function (biomass and species richness), and demographics. Results: The mean stem density data presented a bell-shaped curve with initially increasing, peaking, and subsequently decreasing trends in stem density over time, and the mean biomass data showed a sigmoidal pattern indicating that the rate of biomass accumulation slowed over time. Changes in the density and biomass of Fagus engleriana showed a similar trend to the changes in density and biomass at the community level, which is indicative of the strong influence of this species on the changing patterns of forest structure and function. Around 2015, a shift between recruitment and mortality rates was observed. Deterministic processes were the predominant cause of tree mortality in our study; however, soil deposition that began in 2017 in some of the quadrats resulted in an increase in the contribution of stochastic processes (15% in 2019) to tree mortality. The development of horizontal heterogeneity was observed in forest gaps. Conclusions: Our observations showed a dramatic shift between the recruitment and mortality rates in the stem exclusion stage, and that disturbance increases the uncertainty in forest development increases. The minor changes in species composition are likely linked to regional species pool and the limited role of the life-history strategy of species such as shade tolerance and habitat affinity. Our midterm records of ecological succession exhibited detailed demographic dynamics and contributed to the improvement of an ecological perspective in the stem exclusion stage.

• Korean Journal of Environment and Ecology
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• v.27 no.3
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• pp.344-356
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• 2013

This study is a continuation of the 22 year consecutive study (1972~1993) to monitor community dynamics of forest in Mt. Kwanak. This study was intended to provide basic data for urban forest management in the future by analyzing actual changes in vegetation structure of forest in Mt. Kwanak caused by urban environmental changes. For the past 39 years (1972~2010), average temperature increased by approximate between 1.1 and $1.7^{\circ}C$ and soil acidification (pH $5.40{\rightarrow}4.50$) and contents of $K^+$ ($0.67{\rightarrow}0.25$) and $Ca^{{+}{+}}$ ($3.20{\rightarrow}0.87$) apparently tended to decrease. According to analysis importance percentage and DBH class of community types classified based on DCA, the succession stopped at Quercus mongolica for 39 years. In addition, the succession was expected to be held at Q. mongolica or to shift from Pinus densiflora to Q. mongolica and from Q. acutissima to Q. serrata. Size of trees growing in forest of Mt. Kwanak increased but the number of species and population of trees showed a downward trend for the 39 years and Styrax japonica and Sorbus alnifolia, which are indicator species, increased their dominance continuously. Decrease in contents of $K^+$, $Ca^{{+}{+}}$, and $Mg^{{+}{+}}$ and soil acidification for the past 39 years was found to affect degradation of vegetation structure in Mt. Kwanak.

• Journal of Wetlands Research
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• v.20 no.3
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• pp.243-248
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• 2018

This study was carried out to clarify changes in community structure of Quercus acutissima dominant stand on the south slope of Mt. Danseok-san with fixed twenty quadrates. Five field surveys were conducted from Aug. 1999 to May 2018. During the period, the density lessened to 0.20 in 2012 comparing with 0.33 in 1999. However recent field study in 2018 showed moderate rising to 0.24. In 1999, the DBH class distribution of all trees formed reverse J curve. However, the reverse J curve was torn down, forming bell curve. In 2018, the curve showed similar shape of reverse J shape on the group of young trees, forming bell shape on the group of mature trees. It reveals that DBH 13cm is on the threshold of trees competition trend where the downtrend in the trees are on uptrend. The most dominant Q. acutissima formed bell curve. The peak of the curve shows the shift to the right of the graph as it gets lower by year.In case of Q. mongolica, shows a change in the shape of a low bell as the distribution curve increases. The oak stand in this study is in the process of changing from the initial stage of the secondary forest succession to the intermediate stage. The most dominant tree is Q. acutissima, and the sub-dominant tree is Q. mongolica in present. Considering the age distribution of the two competing tree species, the succession of this stand is expected to transfer to the Q. mongolica-dominant community.

• Korean Journal of Environment and Ecology
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• v.12 no.2
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• pp.119-130
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• 1998

The purposes of this study were to investigate vegetation structure and to present management plan of mountain type green space in Kangwhado, Inchon. The actual vegetation in survey sites(11,331ha) was divided into 19 community types. It was consisted of secondary forest(92.32%) which was Quercus acutissima, Pinus densiflora-Q. acutissima, and Q. mongolica community so on. Artificial planting forest area, such as Robinia pseudoacacia and Pinus rigida forest and others, was 5.40%(612ha) and it was less than cases in other cities in the Metropolitan area. According to the classification by TWINSPAN, 57 survey plots were divided into seven community types; P rigida(community A), Q. acutissima(community B) P. densiflora-Q. acutissima(community C), Q. acutissima-P. densiflora (community D), P. densiflora-Carpinus laxiflora-Q. serrata-Q. acutissima(community E), Q. serrata-Q. mongolica(community F), and Zelkova serrata-Acer mono(community G). From this result, ecological succession trend of vegetation in this area seems to be change from P. densiflora forest through Q. acutissima forest to Q. mongolica, Q. serrata, and C. laxiflora forest. It was similar to the ordinary successional trend of temperate deciduous forest in middle area, Korea. In addition, this study area was showed acid soil(pH 4.17). Therefore, there is a need for managing the soil environment for effective vegetation management.