• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.399-405
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• 2020

This study examined the effect service learning combined with self-directed study had on transferring skills from the university classroom to their practical application in local community centers. The subjects of this study were students who took service learning classes from September 1, 2019 to December 28, 2019. The research question in this paper is 'What is the relationship between service learning-based general classes and self-directed learning?'. That is, how do service learning-based general classes affect sub-elements of self-directed learning? We then tried to determine how the variables of individual learners can affect self-directed learning ability. The results showed that autonomy and problem solving were the greatest at r=.66. Openness and self-assessment (r=.60), autonomy and self-assessment (r=.55) had significant correlation. Learner autonomy had a significant correlation with facilitation and collaboration of service learning (**p<.01). According to this result of the study, it is possible for learners to deepen what they have learned at school and to practice and gain experience through community service. Further, practical problem solving and self-assessment through reflection are possible. Learners were able to inspire responsibility as members of society and increase self-esteem as democratic citizens.

• The Korean Journal of Ecology
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• v.22 no.3
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• pp.139-144
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• 1999

In order to clarify ecological survival strategy of Rumex crispus community dominating under contaminated area of lower region of Kumho riverside including Chimsangyo (CS), Paldalgyo (PD), Talseochon (TS) and Kumhogyo (KH), we analyzed the content of heavy metals and inorganic matter and vegetative growth. R. crispus showed rapid formation of community by high growth rate, high T/R ratio and showed maximum T/R ratio at the contaminated area Talseochon. Nitrogen and phosphorus contents in R. crispus showed high value in shoot than that of root. T/R ratio of nitrogen and phosphorus showed 3.1∼3.6 and 1.5∼4.5 for the early growth stage, and 6.7∼17.3 and 3.9∼8.3 for the late one, respectively. The absorbed heavy metals by riot were translocated to shoot, the heavy metal content in shoot higher than those in root of Cu, Zn, Fe, and Pb for 3.6, 1.7, 1.5 and 4.8 times, respectively. Distribution ratio of the heavy metals in each organ showed 61∼85% and 15∼39% for shoot and root, respectively. R. crispus accumulated heavy metals in the order of Fe>Zn>Cu>Pb in shoot, and showed maximum values of Cu, Zn, Fe and Pb for 89.7, 376.6, 2946.1 and 13.2 ㎍/g dw, respectively at Talseochon in April. A physiological and morphological characteristics of R. crispus showed thickened leaf, increased water content above 80% and rapid growth of shoot. R. crispus showed ecological adaptation to the contaminated area by transportation of heavy metals and inorganic matter to shoot, and by accumulation of Ca ion in root.

• Journal of The Korean Association For Science Education
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• v.32 no.2
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• pp.388-401
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• 2012

This study attempted to propose a theoretical model for STEAM education, entitled to the Ewha-STEAM education model, which could provide more concrete guidelines for science educators and curriculum developers to execute STEAM ideas. We identified key knowledge and key competencies to nurture future creative/convergent human resources. Key knowledge included an understanding of core ideas cutting across traditional disciplinary boundaries as well as the nature of different disciplines. And additionally, key competencies implied such abilities as to explore the scientific world, to resolve problems, and to communicate and collaborate with others. We also added creativity and character as an essential part of key competencies. In order to provide more specific guidelines when developing, implementing, and evaluating STEAM curriculum, we suggested three elements of convergence to consider: 1) unit of convergence (i.e. concept/skills, problem/phenomenon, activity), 2) degree of convergence (i.e. multi-disciplinary, inter-disciplinary, extra-disciplinary), and 3) context of convergence (i.e. personal, societal, global). It is expected that the Ewha-STEAM education model would contribute towards diverse education communities understanding the direction of STEAM education and its educational potentials.

• Journal of Wetlands Research
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• v.6 no.1
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• pp.149-166
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• 2004

Water quality and ecological environment in the Han River estuary was analyzed using the longterm water quality monitoring data from National Fisheries Research and Development Institute (NFRDI) and the existing data collected in this area. Based on the salinity distribution and changes of current direction in the lower Han River and its estuary, boundaries of the estuary were identified and also, distribution patterns of the phyto- and zooplankton, benthos, ichthyoplankton and fish were discussed related with the salinity changes in the macrotidal subestuary of Han River. Seasonal and spatial distribution of salinity suggested that the direct impact of freshwater be limited to the Incheon North Harbour all the year round and even extended to the southern area of Gyunggi Bay near Palmi island during limited time, usually in summer. Upper limit of salt water intrusion through the Han River is likely to be Singok underwater dam located Gimpo, Gyunggi Province, and normally limited to much lower part of the river, Jeonryuri, Gimpo. Biological boundaries of the Han River estuary exceeded the physical boundaries based on the salinity distribution. Many estuarine species in plankton and fish were found at the totally freshwater or saltwater depending on the seasons and tidal cycles. Some estuarine ichthyoplanktons showed extremely limited distributions in the estuary whereas adult fish revealed wide ranges of salinity adaptation. Critical environmental issues in the Han River estuary and its drainage basin are likely to be 1) pressure on development-promoted district for new town in the drainage area of the estuary, 2) reduction of tidal flat by reclamation, 3) pollutant input through river from municipal sewages and industrial wastes, and 4) ecological barrier between river and terrestrial systems by the military wire fence and riverside road.

• Journal of Conservation Science
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• v.29 no.3
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• pp.261-277
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• 2013

This study aims to research the relationship between whitewares and their rare materials from the site of Yanggu and Bunwon through the componential characteristic of the excavated whitewares from the 1st and the 2nd kilns of Chiljeon-ri in Bangsan-myeon, Yanggu-gun. As a result, the sherds were devided according to the chemical compositions of the body and the glaze via their respective production era. However, it considered that the whitewares from Chiljeon-ri had been manufactured with geochemically similar materials and the production process, such as refining and combining materials, had been different. It assumed that the firing temperatures of the whitewares from Chiljeon-ri were around $1,100-1,200^{\circ}C$ and substantially lower than for general whitewares. In the componential analysis, there were disparate properties in the cobalt pigment, which contained trace elements and rare earth elements. A review of the literature revealed a correlation between the whitewares from the late Chosun kiln site in Bunwon-ri and the raw materials from Yanggu-gun, but this was there were various techniques for refining and combining materials in Bunwon-ri.

• Economic and Environmental Geology
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• v.36 no.5
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• pp.365-374
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• 2003

Various deleterious chemicals can be introduced to existing concrete structures from various external sources. The deterioration of concrete by seawater attack is involved in complex processes due to various elements contained in seawater. In the present study, attention was paid to the formation of secondary minerals and characteristics of mineralogical and micro-structural changes involved in concrete deterioration caused by the influence of major seawater composition. The characteristics of deterioration occurred in existing concrete structures was carefully observed and samples were collected at many locations of coastal areas in Busan-Kyungnam. The petrographic, XRD, SEM/EDAX analyses were conducted to determine chemical, mineralogical and micro-structural changes in the aggregate and cement paste of samples. The experimental concrete deteriorations were performed using various chloride solutions (NaCl, CaCl, $MgCl_2$ and $Na_2SO_4$ solution. The experimental results were compared with the observation results in order to determine the effect of major elements in seawater on the deterioration. The alkalies in seawater appear to accelerate alkali-silica reaction (ASR). The gel formed by ASR is alkali-calcium-silica gel which known to cause severe expansion and cracking in concrete. Carbonation causes the formation of abundant less-cementitious calcite and weaken the cement paste. Progressive carbonation significantly affects on the composition and stability of some secondary minerals. Abundant gypsum generally occurs in concretes subjected to significant carbonation, but thaumasite ({$Ca_6/[Si(OH)_6]_2{\cdot}24H_2O$}${\cdot}[(SO_4)_2]{\cdot}[(CO_3))2]$) occurs as ettringite-thaumasite solid solution in concretes subjected to less significant carbonation. Experimentally, ettringite can be transformed to trichloroaluminate or decomposed by chloride ingress under controlled pH conditions. Mg ions in seawater cause cement paste deterioration by forming non-cementitious brucite and magnesium silicate hydrate (MSH).

• Korean Security Journal
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• no.37
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• pp.83-108
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• 2013

Since the end of the Cold War and rapid globalization and technical developments, terrorist groups actively involved in criminal activities. Also criminal entrepreneurs became a major financial revenue for these terrorists groups. This newly patternized activities among terrorist groups is now called as Crime-Terror Nexus" indicating the changing nature of terrorism, which means two traditionally separate phenomena, crime and terrorism, became more similar. This new pattern of terrorism is considered to create synergy for the criminal organizations and terrorist groups, scholars believe that it would become a significant threat to the security of world community in the near future. Although the phenomenon of this crime-terror nexus is significant and imminent threats, there is lack of studies investigation this new evolution of terrorism with empirical data. Moreover there is literally no studies exploring factors relevant to the Crime-Terror Nexus. Therefore, this current study aims to conduct explorative investigation of factors affecting the "Crime-Terror Nexus" with a world terrorism data, MAROB(the Minorities at Risk Organizational Behavior), which is developed by START and Minority at Risk project and contains information terrorist groups in Middle-East and Africa region. Considering the significance of this new terrorism patterns and the challenging nature of conducting empirical studies on this topic, this study has great contribution on the development in the field of criminal justice as well as terrorism.

• Journal of dental hygiene science
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• v.8 no.4
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• pp.387-393
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• 2008

This study was undertaken to determine the halitosis status of urban area in Dae-Gu city. The sample of this study consisted of 332 persons who lived at Dae-Gu city. The results were as follows. 1. The persons consisted of 44.6% male and 55.4% female. The 32.5 % persons were under 38 years and 82.2% of persons were married. 2. The 26.8% persons answered the last meal time was before 1-2 hours and 63.3% persons answered middle halitosis. The 26.3% persons answered the time of worst halitosis was after breakfast and 33.1% persons answered the smell type of halitosis was nasty smell. The 11.4% persons experienced dental treatment for halitosis, and 63.9% persons required dental treatment for halitosis. 3. The 100 ppb~149 ppb concentration of halitosis was 156 persons. Over 150 ppb concentration of halitosis was 54 persons. The average of halitosis concentration was 122.76 ppb and, the 63.3% persons required halitosis management and treatment. An aged persons of the halitosis concentration was significantly increased than younger persons (p < 0.05). Higher smell preception of halitosis was significantly increased in halitosis concentration test practically (p < 0.001). Subjects who treated dental treatment for halitosis was significantly increased (p < 0.01). This study results have informed that the knowledge and management of halitosis was demand and required public relation for halitosis. The halitosis management and education program will improve the oral health. Therefore halitosis management program which based on data collection and planning will be developed and activated in further study.

• Korean Journal of Environment and Ecology
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• v.32 no.1
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• pp.118-131
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• 2018

The forest vegetation of Juwangsan National Park, which is famous for its towering scenic valleys, was syntaxonomically described. The study adopted the $Z{\ddot{u}}rich$-Montpellier School's method emphasizing a matching between species composition and habitat conditions. A combined cover degree and the r-NCD (relative net contribution degree) were used to determine a performance of 265 plant species listed-up in a total of 52 phytosociological $relev{\acute{e}}s$. Nine plant communities were classified through a series of table manipulations, and their distribution and actual homotoneity($H_{act}$) were analyzed. Syntaxa described were Carex gifuensis-Quercus mongolica community, Athyrium yokoscense-Quercus mongolica communiy, Arisaema amurense-Quercus serrata community, Lespedeza maximowiczii var. tomentella-Quercus variabilis community, Tilia rufa-Quercus dentata community, Carex ciliatomarginata-Carpinus laxiflora community, Aristolochia manshuriensis-Zelkova serrata community, Onoclea orientalis-Fraxinus mandshurica community, and Carex humilis var. nana-Pinus densiflora community. A zonal distribution was reviewed and the altitude of about 700 m was the transition zone between the cool-temperate central montane zone (Lindero-Quercenion mongolicae region) and southern submontane zone (Callicarpo-Quercenion serratae region). Only 19 taxa were associated with r-NCD 10% or more, most of which were tree species occurring in the Lindero-Quercenion and some of which was a member of open forests. Species composition of forest vegetation was much less homogeneous, showing the lowest $H_{act}$. Nearly natural forests and/or secondary forests in the Juwangsan National Park were defined as a regional vegetation type, which reflects much stronger continental climate in the Daegu regional bioclimatic subdistrict, rhyolitic tuff predominant, and wildfire interference.

• Journal of the Korean Geographical Society
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• v.51 no.6
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• pp.837-851
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• 2016

The growth and development of Gwangyang city was a result of the POSCO Gwangyang Works, and Gwangyang city is one of typical firm citys in Korea. The objective of this study is to identify and examine the change of migration and population structure in Gwangyang city from 2001 to 2010. Since 1981, total number of population of Gwangyang city increased from 78,478 in 1981 to 145,512 in 2010. The population structure by age was changed with population increase since 2001, and 30-40 aging group was 35% of total in 2010. During 2001-2010, the netmigraion showed -2,925 people, however, the number of inmigrants were overtaking the number of out-migrants since 2008. The most common reason of in-migrants was occupation(49.5%). Factors influencing Gwangyang City's population growth and oversupply are the location of POSCO Gwangyang Works and steel-related enterprises, opening and construction of Gwangyang container berth, the related development projects and establishment of Gwangyang Bay Area Free Economic Zone, and the local policies of Gwangyang City connected with these large-scale national projects. As a result, the number of manufacturing-related businesses increased due to various regional development projects conducted in Gwangyang City, and the growth of the business continued to increase due to the increase of younger people and births.