• Title/Summary/Keyword: community formation

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Biotic and Abiotic Reduction of Goethite (α-FeOOH) by Subsurface Microorganisms in the Presence of Electron Donor and Sulfate (전자공여체와 황산염 이용 토착미생물에 의한 침철석(α-FeOOH) 환원 연구)

  • Kwon, Man Jae;Yang, Jung-Seok;Shim, Moo Joon;Lee, Seunghak;Boyanov, Maxim;Kemner, Kenneth;O'Loughlin, Edward
    • Journal of Soil and Groundwater Environment
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    • v.19 no.1
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    • pp.54-62
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    • 2014
  • To better understand dissimilatory iron and sulfate reduction (DIR and DSR) by subsurface microorganisms, we investigated the effects of sulfate and electron donors on the microbial goethite (${\alpha}$-FeOOH) reduction. Batch systems were created 1) with acetate or glucose (donor), 2) with goethite and sulfate (acceptor), and 3) with aquifer sediment (microbial source). With 0.2 mM sulfate, goethite reduction coupled with acetate oxidation was limited. However, with 10 mM sulfate, 8 mM goethite reduction occurred with complete sulfate reduction and x-ray absorption fine-structure analysis indicated the formation of iron sulfide. This suggests that goethite reduction was due to the sulfide species produced by DSR bacteria rather than direct microbial reaction by DIR bacteria. Both acetate and glucose promoted goethite reduction. The rate of goethite reduction was faster with glucose, while the extent of goethite reduction was higher with acetate. Sulfate reduction (10 mM) occurred only with acetate. The results suggest that glucose-fermenting bacteria rapidly stimulated goethite reduction, but acetate-oxidizing DSR bacteria reduced goethite indirectly by producing sulfides. This study suggests that the availability of specific electron donor and sulfate significantly influence microbial community activities as well as goethite transformation, which should be considered for the bioremediation of contaminated environments.

A Study on Promoting the Intra-Regional Trade in Southeast Asia (동남아시아 역내교역 결정요인 분석 및 시사점)

  • Ra, Hee-Ryang
    • The Southeast Asian review
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    • v.24 no.2
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    • pp.35-79
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    • 2014
  • This study examines the measures for the activation and the growth of intra-regional trade in Southeast Asia taking a look at the four dimensions of tariff rates, non-tariff barriers, trade facilitations, and trade infrastructures. Utilizing a gravity model, we performed empirical analysis and discussed the policy implications with the priorities to implement. To expand the intra-regional trade in Southeast Asia it would be necessary to enhance the level of trade facilitations and provide trade infrastructures, such as ports and airports as well as cutting the tariff rates and eliminating the non-trade barriers. In particular, in the case of exports of ASEAN6 to ASEAN6 the infrastructure is the important factor. Also, in the case of the exports of ASEAN6 to CLMV(Cambodia, Laos, Myanmar, and Vietnam), it is expected that eliminating non-tariff barriers and enhancing trade facilitations may play important roles in the progress of intra-regional trade. These results may provide the important implications for Southeast Asian countries, which are trying to promote intra-regional trade ahead of the constitution of ASEAN Economic Community by 2015. Southeast Asian countries could be evaluated to achieve a certain level of trade liberalization and economic integration through the formation of AFTA. But in order for Southeast Asia to develop to advanced economic integrated region it requires mutual cooperations and policy harmonizations among regional countries. Also, for the elimination of non-tariff barriers, promoting trade facilitations, and providing infrastructures, the administrative, legal, and institutional measures would have to be fulfilled in advance. In addition, capital investment for constructing infrastructures would be necessary to realize the intra-regional trade expansion. However, to achieve the goal, it would require a large capital investment and highly mandated policy considerations and harmonizations among Southeast Asian countries in terms of further trade liberalization and economic integration.

Distribution of Vegetation and Geomorphology Characteristics of the Water Spider(Argyroneta aquatica) Habitat in the Jeongok Lava Plateau, Central Korea (전곡 용암대지 물거미 서식지의 지형특성과 식생 분포)

  • Lee, Min Boo;Lee, Sang Young
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.4
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    • pp.57-73
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    • 2017
  • The formation of the lava dam of the paleo lake blocked the entrance to the Chatancheon River on the Jeongok lava plateau and it suddenly transformed the terrestrial ecosystem into the aquatic one by the overflow. The spiders in the lava dam adapted in the wetland and evolved into water spiders that could survive by forming bubble houses. Since then, the lava dam was connected to the present Hantangang River due to the dissection and the lake became a terrestrial environment, a small area of marsh composed of primarily clay soil layer. Change in water level of the habitat and thus the extension of the terrestrial area made the species a endangered now. This study carried out frequency of occurrence, degree of wetness and plant habitats of the vascular plant in the water spider habitat. As a result of this study, total 180taxa are of 55 (30.6%) wetland plant groups and of 113 (62.8%) upland plant groups except facultative plant groups. Among the wetland plant groups, the Isachne globosa community occupied the largest area, where the water spiders were most observed. The result of this study, the classification and the types of vascular plant species, would provide useful information for the sustaining healthy wetland ecosystem and the restoration of the habitat for the water spiders.

Recognition and Visualization of Crack on Concrete Wall using Deep Learning and Transfer Learning (딥러닝과 전이학습을 이용한 콘크리트 균열 인식 및 시각화)

  • Lee, Sang-Ik;Yang, Gyeong-Mo;Lee, Jemyung;Lee, Jong-Hyuk;Jeong, Yeong-Joon;Lee, Jun-Gu;Choi, Won
    • Journal of The Korean Society of Agricultural Engineers
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    • v.61 no.3
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    • pp.55-65
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    • 2019
  • Although crack on concrete exists from its early formation, crack requires attention as it affects stiffness of structure and can lead demolition of structure as it grows. Detecting cracks on concrete is needed to take action prior to performance degradation of structure, and deep learning can be utilized for it. In this study, transfer learning, one of the deep learning techniques, was used to detect the crack, as the amount of crack's image data was limited. Pre-trained Inception-v3 was applied as a base model for the transfer learning. Web scrapping was utilized to fetch images of concrete wall with or without crack from web. In the recognition of crack, image post-process including changing size or removing color were applied. In the visualization of crack, source images divided into 30px, 50px or 100px size were used as input data, and different numbers of input data per category were applied for each case. With the results of visualized crack image, false positive and false negative errors were examined. Highest accuracy for the recognizing crack was achieved when the source images were adjusted into 224px size under gray-scale. In visualization, the result using 50 data per category under 100px interval size showed the smallest error. With regard to the false positive error, the best result was obtained using 400 data per category, and regarding to the false negative error, the case using 50 data per category showed the best result.

On the Global and Local Environmental Dependence of Type Ia Supernova Luminosity from the Analysis of SALT2 and MLCS2k2 Light-Curve Fitters

  • Kim, Young-Lo;Lee, Young-Wook
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.40.3-40.3
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    • 2019
  • There is growing evidence for the dependence of Type Ia supernova (SN Ia) luminosities on the environments. The origin of this correlation, however, is under debate. In order to explore the physical origin of the trend in detail, we analyze SN Ia light-curves by combining a sample of 1231 SNe Ia over a wide redshift range (0.01 < z < 1.37) in various SN surveys and employing two independent light-curve fitters of SALT2 and MLCS2k2. Although SALT2 is the most widely used fitter in the SN community, MLCS2k2 has a novelty in the context of an investigation of the luminosity evolution of SNe Ia. For this reason we use both fitters and analyze them separately. We also determine a stellar mass and a star formation rate (SFR) for a sample of ~600 host galaxies. In addition, because recent low-redshift studies suggest that this dependence manifests itself most strongly when using the local SFR at the SN location, we introduce a new method to infer the local environments by restricting the SN Ia sample in globally star-forming host galaxies to a low-mass host galaxy subset (${\leq}10^{10}M_{\odot}$). We find that SNe Ia in low-mass and star-forming host galaxies are fainter than those in high-mass and passive hosts, after light-curve corrections. Especially, for the first time in host studies, we show that SNe Ia in locally star-forming environments are $0.081{\pm}0.018$ mag fainter ($4.5{\sigma}$) than those in locally passive environments from the sample including SNe at the high-redshift range. Considering the significant difference in the mean stellar population age between these environments, the result would suggest that the origin of the environmental dependence is the luminosity evolution of SNe Ia.

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Exploring the Lifelong Education Field Experience of Adult College Students (성인대학생의 평생교육 현장실습 경험 탐구)

  • Song, Seong-Suk
    • Journal of Industrial Convergence
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    • v.19 no.5
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    • pp.47-59
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    • 2021
  • This study explored the lifelong education field experience of adult college students. For this purpose, a qualitative case study was conducted with 5 adult college students from November 17, 2020 to May 14, 2021 through practical diaries, assignment analysis and in-depth interviews. As a result of the study, we discovered two things. First, the lifelong education field practice experience is a 'mountain to overcome! Lifelong education field practice', 'expansion of awareness of lifelong education', 'confidence field practice', and 'A picture is worth a thousand words'were revealed. Second, the meaning of the lifelong education field experience is 'formation of a learning community through teamwork with colleagues', 'realization that people are the core of the lifelong education', 'changes in the professional identity of the lifelong education history', and 'The life of a lifelong learning practitioner who wants to challenge' life' was revealed. These results will lead field training participants to grow qualitatively, and can be used as basic data for securing professional expertise and providing quality field training. A follow-up study was proposed for adult college students who belong to other colleges.

The Americanization of a Canadian National Icon Anne of Green Gables (캐나다의 국가적 아이콘 『빨강머리 앤』의 미국화)

  • Kang, Suk Jin
    • Journal of English Language & Literature
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    • v.54 no.4
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    • pp.561-577
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    • 2008
  • L.M. Montgomery's Anne of Green Gables is not only confidently labelled a Canadian classic but also placed as a national icon along with the moose, the beaver, and the Habs in Canada. Anne's 'Canadianness' is partly due to its location in the rural world of Prince Edward Island. The fictional Avonlea is described as the ideal space where Canadian spirit can interact with the personified surrounding landscapes through Celtic imagination. Additionally, the communal bond of Avonlea fully demonstrates Scottish Canadian identities. The Scottish national character of Avonlea is responsible for clannishness of the Cuthberts and the Lyndes. The disrespect to the French is also due to Scottish heritage in Avonlea. As an outsider Anne wants to be integrated into the community of Avonlea, and successfully adapts herself to the regional shared values. Meanwhile she partly challenges the strictness and rigidness of the born Canadian Avonlea residents. Despite its Canadian origin, Anne of Green Gables is accepted as part of the American canon of children's literature in the Unite States. The configuration of Anne as an American heroine is noticeable among American scholars: by relocating it to the US the female Bildungsroman in the nineteenth century America, a group of literary critics adapt Anne as an American girl for American readers. The heroine of Anne of Green Gables is linked to American novels such as Louisa May Alcott's Little Women, Kate Douglas Wiggin's Rebecca of Sunnybrook Farm and Gene Stratten Porter's A Girl of the Limberlost. Anne is even classified as another Caddie by American literary critics: Anne is placed at the center of Caddie Woodlawn Syndrome as another Wisconsin pioneer child. Canadian identity of Anne is intentionally excluded and Anne was reborn as an American girl in the U.S. In this context, Anne functions as a sign of nation and a site for cross-national identity formation.

The Utilization of Dental Hygienists in Oral Healthcare Exchanges between the South and North Korea

  • Ahn, Eunsuk;Han, Ji-Hyoung;Kang, Kyung-Hee;Jang, Young-Eun;Jeon, Ki-Ha;Park, Jeong-Ran
    • Journal of dental hygiene science
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    • v.21 no.1
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    • pp.63-69
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    • 2021
  • Background: This study aimed to identify the role of dental hygienists in exchanges between North and South Korea to lower gaps in the level of dental healthcare between the two countries by conducting a Delphi survey with specialists and identifying alternative policies regarding the utilization of dental hygienists in such exchanges. Methods: Two Delphi surveys were conducted with the participation of nine specialists, and descriptive statistical analyses including mean and standard deviation were performed on the collected data. Results: Among methods of exchange and cooperation regarding oral healthcare under the current North Korean medical system, the issue considered most urgent was the "establishment of oral healthcare infrastructure." The most important short-term strategy was identified as the "selection and formation of partnerships in the field of inter-Korean oral health exchange and cooperation." The mid-term strategy was identified as the "establishment of cooperation in the dental industry, centered on educational cooperation projects." The long-term strategy included "joint R&D projects, oral health surveys, and business development." In order to determine how best to use dental hygienists during inter-Korean exchanges and cooperation, the respondents placed urgency on the "establishment of joint cooperation projects for oral health promotion and early examination and the treatment of dental diseases and planning of community research projects" and "the role of oral health education and media development for residents." Conclusion: Cooperation is necessary regarding the preparation of oral healthcare exchanges that aim to encourage unity between North and South Korea and reduce the gaps between the North and South regarding oral health conditions. Therefore, continuous and reasonable discussions and research are needed regarding the utilization of dental hygienists in such exchanges.

A Study on Thermal Satisfaction of Domestic Heat Wave Reduction Facilities (국내 폭염 저감 시설의 온열 만족도에 대한 연구)

  • Jun, Yong-Joon;Park, Lyool;Park, Kyung-Soon
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.18 no.1
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    • pp.1-11
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    • 2022
  • As abnormal climates occur due to the increase in greenhouse gases at home and abroad, various problems such as human casualties, crop damage, energy depletion, and economic loss due to heat diseases, which are one of the extreme climate phenomena, are following one after another. In response, the government has established the 'Climate Crisis Response Special Committee' since 2018, when it recorded the greatest damage in history due to heat waves, and has been carrying out budget formation and reform of laws and systems every year to respond to heat waves. However, in relation to the heat wave damage reduction facility that is being expanded with a large budget, there is no prior research related to the degree of heat loss due to the use of the facility, the difference in effects between specific groups, and the economic effect that comes back compared to the invested budget. Therefore, from a midto long-term perspective, it is expected that it will be difficult to establish a clear direction for policy making. Therefore, in this study, representative facilities were selected according to the principle of heat reduction among the currently expanded heat damage reduction facilities, and a questionnaire survey was conducted for users of each reduction facility (waterfall, awning, pond, and elastic pavement). Accordingly, the change in the sense of heat according to the use of the heat damage reduction facility was checked, and the change in the sense of heat according to the group characteristics (gender, age, metabolic rate) was analyzed to examine the characteristics of the relationship between the facility and the users.

Research on the Impacts of Wilderness Learning Experiences as an Educational Curriculum in Higher Education (대학교육에서의 교육적 커리큘럼으로써 광야학습경험의 효과 연구)

  • Lee, Jongmin
    • Journal of Christian Education in Korea
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    • v.69
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    • pp.105-137
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    • 2022
  • This paper is to study the characteristics of outdoor wilderness education and the impacts of outdoor wilderness experience on the participants in higher education. The first part of this paper addresses the common components of outdoor wilderness programs: adventure or self-discovery in disequilibrium, small groups for accountability in a temporary community, problem solving processes for decision making in real situations, solo time for integration in solitude, and leadership styles and role of the trip leaders. These elements of outdoor wilderness programs help the participants to achieve their goals according to its mission. The second part of this paper divides outdoor wilderness programs into three categories according to the objectives and outcomes of outdoor wilderness education: orientation programs for incoming students, personal leadership development programs, and professional training programs. The impacts of outdoor wilderness experiences on the participants of different programs in higher education were reviewed. Then guidelines for spiritual formation prorgams were proposed for Christian educators who are involved in wilderness programs in higher education to develop their practical wilderness experiences into holistic development programs according to its mission and goals.