• Journal of Korean Society of Industrial and Systems Engineering
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• v.31 no.3
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• pp.43-51
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• 2008

Recent advances in mobile computing technologies and platform-independent information systems have enabled to realize a ubiquitous environment. Community computing has been developed as a useful tool for realizing collaborative services in a ubiquitous environment. In this paper, we present a formal model of a ubiquitous space that takes community concept into consideration and propose two management frameworks that prevent conflicts among communities. To demonstrate the validity of the proposed frameworks, an example for coordinating two communities is provided.

• Ocean and Polar Research
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• v.24 no.3
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• pp.215-223
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• 2002

Symbiosis of chemoautrophic bacteria with the members of hydrothermal vent and cold seep communities in the deep-sea were examined by histology using transmission electron microscopy; Bathymodiolus spp. from Sagami Bay, the Iheya Ridge and the North Fiji Basin; and Ifremeria nautilei from the North Fiji Basin. Two species of Bathymodiolus, each from Sagami Bay and the Iheya Ridge harbored methane-oxidizing symbionts within their gill tissues. Vent gastropod Ifremeria nautilei from the hydrothermal vents of the North Fiji Basin housed two types of symbionts; one sulfur-oxidizing type and the other methane-oxidizing type. The occurrence of chemosynthetic symbionts in these organisms were expected before-hand based on the ecological observations of their habit. The other members of these groups from world oceans and the recent advances in the symbiosis of the vent and seep communities were reviewed.

• Korean Journal of Ecology and Environment
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• v.46 no.3
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• pp.460-470
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• 2013

Forest vegetation of Choksangsan area in the Deogyusan National Park is classified into mountain forest vegetation. Mountain forest vegetation is subdivided into deciduous broad-leaved forest, valley forest, coniferous forest, afforestation and other vegetation. Including 103 communities of mountain forest vegetation and 8 communities of other vegetation, the total of 111 communities were researched; the mountain forest vegetation classified by physiognomy classification are 36 communities deciduous broad-leaved forest, 26 communities of valley forest, 10 communities of coniferous forests, 31 plantation and 8 other vegetation. As for the distribution rate for surveyed main communities, Quercus mongolica, Quercus variabilis communities account for 65.96 percent of deciduous broad-leaved forest, Fraxinus mandshurica community takes up 22.50 percent of mountain valley forest, Pinus densiflora community holds 63.27 percent of mountain coniferous forest holds. In conclusion, minority species consisting of Quercus mongolica, Fraxinus mandshurica, Quercus serrata, Pinus densiflora, and Quercus variabilis are distributed as dominant species of the uppermost part in a forest vegetation of Choksangsan in Deogyusan National Park. In addition, because of vegetation succession and climate factors, numerous colonies formed by the two species are expected to be replaced by Quercus mongolica, Carpinus laxiflora and Fraxinus mandshurica which are climax species in the area.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.405-413
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• 2015

We classified the streamside plant community by phyto-sociological method and analyzed the relationship between environment factors and vegetation structure by using the classification and ordination method. We found that twenty one plant communities were classified according to dominant species at the natural streamside valley forest with surveying the 65 quadrats (10 m × 10 m). From the survey results, the hardwood plant communities were classified as streamside valley forest and the softwood plant communities as riparian forest according to the degree of flooding. The valley forest had a distribution of 17 plant communities which was 65% (42 quadrats) of 65 quadrats: Maackia amurensis community, Betula davurica community, Quercus variabilis community, Pinus densiflora community, Q. serrata community, Prunus sargentii community, and Meliosma oldhamii community etc. The riparian forest had a distribution of four plant communities which was 35% (23 quadrats) of 65 quadrats: Salix koreensis community, S. rorida community, S. purpurea var. japonica community, and S. glandulosa community, etc. From the two-way indicator species analysis (TWINSPAN) analysis, we found indicator species Oplismenus undulatifolius and Lindera obtusiloba for the streamside valley forest and Humulus japonicus, Phragmites japonica, and S. koreensis for the riparian forest. From the results of the canonical correspondence analysis (CCA), coordinates, altitude, and stream structure showed low correlation to the distribution of the plant community. Therefore, it seemed that valley forest and riparian forest were distinguished by the stream gradient and waterway width which determined by the stream water level.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.271-281
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• 2019

Background: The plant communities within reservoir drawdown zones are ecologically important as they provide a range of ecosystem services such as stabilizing the shoreline, improving water quality, enhancing biodiversity, and mitigating climate change. The aim of the study was therefore to identify the major environmental factors affecting these plant communities within the drawdown zone of the Soyangho Reservoir in South Korea, which experiences a monsoonal climate, and thereafter to (1) elucidate the plant species responses and (2) compare the soil seedbank composition along main environmental gradients. Results: Two main environmental gradients affecting the plant community structure were identified within the drawdown zone; these were a vertical and longitudinal gradient. On the vertical dimension, a hydrological gradient of flood/exposure, the annual-dominated plant community near the water edge changed to a perennial-dominated community at the highest elevation. On the longitudinal dimension from the dam to the upstream, plant species composition changed from an upland forest-edge community to a lowland riverine community, and this was correlated with slope degree, soil particle size, and soil moisture content. Simultaneously, the composition of the soil seedbank was separated along the vertical gradient of the drawdown zone, with mainly annuals near the water edge and some perennials at higher elevations. The species composition similarity between the seedbank and extant vegetation was greater in the annual communities at low elevation than in the perennial communities at higher elevation. Conclusions: The structures of plant community and soil seedbank in the drawdown zone of a monsoonal riverine reservoir were changed first along the vertical and secondly along the longitudinal gradients. The soil seedbank could play an important role on the vegetation regeneration after the disturbances of flood/exposure in the drawdown zone. These results indicate that it is important to understand the vertical and longitudinal environmental gradients affecting shoreline plant community structure and the role of soil seedbanks on the rapid vegetation regeneration for conserving and restoring the drawdown zone of a monsoonal reservoir.

• Korean Medical Education Review
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• v.23 no.3
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• pp.194-203
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• 2021

Learning communities in medical education have demonstrated favorable outcomes in terms of students' learning, professional development, and wellness. Despite these strengths and the widespread adoption of learning communities in US medical schools, there has been little interest in medical learning communities in Korea. In this context, the present study examined the development and implementation of the Yonsei Medical Learning Community (YMLC) and analyzed its outcomes and areas of improvement. The Yonsei University College of Medicine has operated a learning community as part of the undergraduate medical education curriculum since 2014. The YMLC is the first program of its type in Korea. The overall structure of the YMLC consists of four distinct communities (pillars), which are named after four distinguished alumni, and each pillar is organized into five learning community classes. Each class is vertically integrated across students in different medical school years, and one faculty advisor is matched to about 30 students. As the YMLC focuses on fostering reflective practice in students and providing them with opportunities to build teamwork and experience social relatedness, two educational approaches have been adopted: reflective writing and mentoring and community activities. In this study, we obtained and analyzed second-year students' feedback on the YMLC curriculum and identified its achievements, merits, and areas that need improvement. The results have shown that over 75% and 60% of respondents reported satisfaction with reflective writing and mentoring and community activities, respectively. The educational activities of the learning community helped students regularly reflect on their learning and progress and establish close relationships with faculty advisors. However, several areas of improvement regarding content, format, and logistical issues were also identified. The present findings may provide valuable information for other institutions to develop learning communities relevant to their own context.

• Journal of Ecology and Environment
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• v.47 no.1
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• pp.1-13
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• 2023

Background: The positive effects of Arctic plants on the soil environment and plant-species co-occurrence patterns are known to be particularly important in physically harsh environments. Although three dominant plants (Cassiope tetragona, Dryas octopetala, and Silene acaulis) are abundant in the Arctic ecosystem at Ny-Ålesund, Svalbard, few studies have examined their occurrence patterns with other species and their buffering effect on soil-temperature and soil-moisture fluctuation. To quantify the plant-species co-occurrence patterns and their positive effects on soil environments, I surveyed the vegetation cover, analyzed the soil-chemical properties (total carbon, total nitrogen, pH, and soil organic matter) from 101 open plots, and measured the daily soil-temperature and soil-moisture content under three dominant plant patches and bare soil. Results: The Cassiope tetragona and Dryas octopetala communities increased the soil-temperature stability; however, the three dominant plant communities did not significantly affect the soil-moisture stability. Non-metric multidimensional scaling separated the sampling sites into three groups based on the different vegetation compositions. The three dominant plants occurred randomly with other species; however, the vegetation composition of two positive co-occurring species pairs (Oxyria digyna-Cerastium acrticum and Luzula confusa-Salix polaris) was examined. The plant species richness did not significantly differ in the three plant communities. Conclusions: The three plant communities showed distinctive vegetation compositions; however, the three dominant plants were randomly and widely distributed throughout the study sites. Although the facilitative effects of the three Arctic plants on increases in the soil-moisture fluctuation and richness were not quantified, this research enables a deeper understanding of plant co-occurrence patterns in Arctic ecosystems and thereby contributes to predicting the shift in vegetation composition and coexistence in response to climate warming. This research highlights the need to better understand plant-plant interactions within tundra communities.

• Journal of the Korean Institute of Rural Architecture
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• v.25 no.3
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• pp.37-45
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• 2023

This study is conducted to provide an empirical review on how schools play a pivotal role in the regional communities. For this, the use of closed schools, activities to revive small-scale schools, and activities related to nearby schools outside the village were analyzed for villages that have participated and have been awarded in the Contest for Making Happy Rural Communities by the Ministry of Agriculture, Food and Rural Affairs. The results of this are as follows. Out of 204 villages that won the contest, there were 19 cases of school closures. Of these 19 cases, there are 17 cases in which the closed school facilities still exist. For the two remaining cases, there are no buildings and only the site remains. To summarize the use of these schools, the functions are being combined and are determined within the range that local residents can operate. The impact or success factors on the region can be summarized into five main categories through the revival of schools in the crisis of closure. First, it was an opportunity to lay an organizational foundation for village projects in the future by reorganizing the village's organization, such as the formation of a village promotion committee to revive the schools. Second, it did not just introduce outsiders to increase the population, but supported housing and jobs for them to successfully settle down. Third, a cultural community was created with senior and junior residents, and finally, the residents became teachers or formed a village education communities such as lifelong education. In the relationship with schools existing outside the village, activities with members of the surrounding schools and linked activities are being carried out in the sense of "school".

• Korean Journal of Environmental Biology
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• v.18 no.1
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• pp.69-75
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• 2000

The vegetation structure and soil characteristics in Koelreuteria paniculata communities of Taean-Gun and Anmyondo were studied. The Koelreuteria paniculata community in Anmyondo had two vegetation layers, lower-tree and herb layers, but the Koelreuteria paniculata community in Anmyondo had three vegetation layers, subtree, shrub, and herb layers. Also the Koelreuteria paniculata was only the species of subtree layers in the Koelreuteria paniculata community of Anmyondo, but the subtree layer in the Koelreuteria paniculata community of Taean-Gun consisted of Pinus thunbergii, Cornus walteri, Celtis jessoensis, Celtis sinensis, and Evodia danielii. The soil organic matter, total N, available P, CEC, and exchangeable K, Ca, Mg, and Na concentrations were greater in the two Koelreuteria paniculata community than in the adjacent forest. The range of soil pH in the two Koelreuteria paniculata communities were 6.3-7.0, but those in adjacent forests were 4.7-5.5. [Dierssen scale, Vegetation classification, Forest soil] .

• Journal of the Korean School Mathematics Society
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• v.19 no.4
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• pp.417-439
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• 2016

The purpose of this study is to compare and analyze the effects of teaching based on learning-communities approach to mathematics for 7th grade students. Two classes of 7th graders at two different middle schools in same city were selected as the experimental group and the control group respectively. Students in the experimental group learned mathematics in a learning-community while their counterparts in the control group received the traditional whole-class instruction employed in most schools. The results are as follows. Firstly, there was no statistically significant difference in mathematics achievement between the experimental group and the control group. Secondly, between the two groups, there were statistically significant differences in students' attitudes toward mathematics. Participants enjoyed the learning process itself by asking difficult questions to one another, sharing their ideas freely and figuring problems out for themselves. During these active participations, they displayed more confidence and interest in learning mathematics.