• Journal of Ecology and Environment
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• 제36권4호
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• pp.235-243
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• 2013

In Korea, where the plain land is greatly deficient as a mountainous nation, most of riparian zones were transformed into agricultural fields and urban areas. Excessive use of the land, which is close to river, makes the rivers enduring severe pollution stresses. Disappearance of riparian buffer, which plays a function of filter in the riverside, appears as a main factor aggravating water pollution of rivers. In this respect, it is imperative to restore the lost riparian vegetation. This study found out restoration models of riparian vegetation from the Bongseonsa stream, which has remnant riparian vegetation patches as a conservation reserve. Feasible reference information applicable for restoration of riparian vegetation was shown in the species level in the order of herb, shrub, and tree and sub-tree zones as far away from the waterway. Those information could contribute to restoring integrate and healthy rivers and streams beyond simple landscaping differently from the other restoration projects when they will be applied to the restoration project to be carried out in the future. In addition, the spatial range of river and stream, background that riparian zone disappeared in Korea, and application plan of the obtained reference information were discussed.

• Journal of Preventive Medicine and Public Health
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• 제38권2호
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• pp.163-169
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• 2005

Objectives: Pedestrian traffic injuries have been an important cause of childhood mortality and morbidity for decades. The aim of this study was to describe the epidemiological characteristics of child pedestrian traffic injuries that occurred during 2000 in one metropolitan city and its school-zones, and to determine the factors associated with those accidents. Methods: A cross-sectional study was performed in 2001. Police records were used to identify the cases of pedestrian injury. Children aged between 6 and 15 years, injured during road walking, were included in this study. A direct survey of the environmental factors within the school-zones in study area (n=116) was also performed. Self-administered questionnaires, via mail and telephone surveys, were used to assess the safety education programmes. The schools were divided into two groups according to the occurrence of pedestrian traffic injuries in their school-zone. Results: Pedestrian injuries (n=597) were found to account for 3.2% of all traffic injuries in the subject area. The epidemiological characteristics were not significantly different between genders. There were some significant risk factors within the environmental factors, such as local road (OR: 2.3, 95% CI=1.05-5.35), heavy traffic volume (OR: 2.2, 95% CI=1.00-5.04), poor visibility of speed-limit signs (OR: 2.8, 95% CI=1.25-6.42), no separation of pedestrian routes from cars (OR: 2.6, 95% CI=1.02-6.75) and barriers on the pedestrian routes (OR: 2.2, 95% CI=1.01-5.08). Only one factor, that of education in a safety-park (OR: 0.3, 95% CI=0.09-0.96), was significantly associated in the traffic and pedestrian safety education factors. Conclusion: Significant associations with pedestrian injury risk were identified in some of the modifiable environmental factors than in the educational factors.

• Nuclear Engineering and Technology
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• 제50권1호
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• pp.132-139
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• 2018

Nanocrystalline reduced activation ferritic/martensitic (RAFM) steel samples were prepared using surface mechanical attrition treatment (SMAT). Un-SMATed and SMATed reduced activation ferritic/martensitic samples were irradiated by helium ions at $200^{\circ}C$ and $350^{\circ}C$ with 2 dpa and 8 dpa, respectively, to investigate the effects of grain boundaries (GBs) and temperature on the formation of He bubbles during irradiation. Experimental results show that He bubbles are preferentially trapped at GBs in all the irradiated samples. Bubble denuded zones are clearly observed near the GBs at $350^{\circ}C$, whereas the bubble denuded zones are not obvious in the samples irradiated at $200^{\circ}C$. The average bubble size increases and the bubble density decreases with an increasing irradiation temperature from $200^{\circ}C$ to $350^{\circ}C$. Both the average size and density of the bubbles increase with an increasing irradiation dose from 2 dpa to 8 dpa. Bubbles with smaller size and lower density were observed in the SMATed samples but not in the un-SMATed samples irradiated in the same conditions, which indicate that GBs play an important role during irradiation, and sink strength increases as grain size decreases.

• 대한토목학회논문집
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• 제32권5D호
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• pp.429-435
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• 2012

본 연구는 통근 통학시 자전거 이용환경 평가할 수 있는 평가모형을 개발하여 평가지표를 통해서 현재 자전거 이용환경을 평가하고 향후 개선사항 및 시사점을 제시하고자 하였다. 평가지표 개발방향은 자전거 이용자들의 필요성, 새로운 정책 반영, 종합 평가지표 구축, 관련연구 검토와 같이 크게 4가지 측면에서 통근 통학 자전거 이용환경 평가지표 개발방향을 정립한 후 기존 평가지표 검토 및 FGI를 통해 1차 평가항목을 선정하고, 평가지표의 적합성 검증을 통해 최종평가지표를 도출하였다. 본 연구 결과를 간략히 요약하면 다음과 같다. 첫째 자전거 이용평가에서 존별 평가를 적용하여 존 단위의 개선점 제시, 둘째 GIS를 이용한 시설물 현황 및 모형분석 결과 제시, 셋째 스파이더 맵을 이용한 각 존별 주요항목 결과의 비교를 명확히 하였다.

• 한국물환경학회지
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• 제32권2호
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• pp.205-215
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• 2016

In order to improve water quality in the Paldang Lake, a riparian vegetation belt, treatment wetland, and artificial floating island were designed for introduction in the upland field, the estuary of tributaries, and the section of water facing mountainous land, respectively. We synthesized vegetation information collected from a reference river and found that herbaceous, shrubby, and tree vegetation zones tended to be dominated by Phragmites japonica, Phalaris arundinacea, etc.; Salix gracilistyla, S. integra, etc.; and S. koreensis, S. subfragilis, and Morus alba, respectively. In our plan, the herbaceous vegetation zone, which is established on floodplains with a high frequency of disturbance, will be left in its natural state. A shrubby vegetation zone will be created by imitating the species composition of the reference river in the ecotone between floodplain and embankment. A tree vegetation zone will be created by imitating species composition on the embankment slope. In the treatment wetland, we plan to create emerged and softwood plant zones by imitating the species composition of the Zizania latifolia community, the Typha orientalis community, the P. communis community, the S. integra community, and the S. koreensis community. The floating island will be created by restoring Z. latifolia and T. orientalis for water purification purposes.

• Restorative Dentistry and Endodontics
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• 제44권1호
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• pp.8.1-8.7
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• 2019

Objectives: Irrigants are imperative in endodontic therapy for the elimination of pathogens from the infected root canal. The present study compared the antimicrobial efficacy of octenidine dihydrochloride (OCT) with chlorhexidine (CHX) and sodium hypochlorite (NaOCl) against Staphylococcus epidermidis (S. epidermidis) for root canal disinfection. Materials and Methods: The minimum inhibitory concentration (MIC) was obtained using serial dilution method. The agar diffusion method was then used to determine the zones of inhibition for each irrigant. Lastly, forty 6-mm dentin blocks were prepared from human mandibular premolars and inoculated with S. epidermidis. Samples were randomly divided into 4 groups of 10 blocks and irrigated for 3 minutes with saline (control), 2% CHX, 3% NaOCl, or 0.1% OCT. Dentin samples were then collected immediately for microbial analysis, including an analysis of colony-forming units (CFUs). Results: The MICs of each tested irrigant were 0.05% for CHX, 0.25% for NaOCl, and 0.0125% for OCT. All tested irrigants showed concentration-dependent increase in zones of inhibition, and 3% NaOCl showed the largest zone of inhibition amongst all tested irrigants (p < 0.05). There were no significant differences among the CFU measurements of 2% CHX, 3% NaOCl, and 0.1% OCT showing complete elimination of S. epidermidis in all samples. Conclusions: This study showed that OCT was comparable to or even more effective than CHX and NaOCl, demonstrating antimicrobial activity at low concentrations against S. epidermidis.

• 교육시설
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• 제15권6호
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• pp.12-21
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• 2008

The purpose of this study was to research on relationship between the circulation system of students and resident users in elementary school complex. 4 elementary schools in Seoul were chosen for this study. The method of this study is a plan analysis, an on-the-spot survey, and user behavior observation. The circulation system of students and resident users at school zone(outside) and Community school were observed. The following is the main results of this study. First, circulation systems are mixed between public zone and student zone in Community school. Therefore these zones shall be planed separated. Second, resident users tend to go directly to the facilities gathered together. Therefore main entrance has to be located closely to the facilities gathered together. In accordance with this results, both the main entrance of Community school and the students facilities have to be considered when planing the circulation system in school from now on.

• 한국물환경학회지
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• 제34권5호
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• pp.447-461
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• 2018

To realize river restoration that ecological characteristics of the river are reflected, we classified the river into four reaches of valley stream, upstream, midstream, and downstream based on substrate as well as riverbed gradient obtained from the relationship between distance from the river mouth, and above sea level. Considering that the rivers of Korea have been dominated by various and intense artificial interferences over a lengthy period, we determined cross sectional range of the river based on the geological map and clarified transformation degree by reach. Vegetation profile diagram was prepared by depicting horizontal range and vertical stratification of major vegetation appearing in a belt transect of 10 m breadth installed between weirs constructed in both sides of the river. Restoration models by river reach were prepared based on breadth of waterway, bare ground, herb, shrub, and tree dominated vegetation zones on vegetation profiles wherein a flooding regime was reflected. Species composition information collected from vegetation established in each zone was systematized to use for restoring each reach ecologically. Further, background that longitudinal reaches and horizontal zones were divided, was discussed by comparing with case studies in foreign countries. In addition, necessity of ecological restoration of the river was discussed based on degree of integrity of Korean rivers, ecological significance of riparian vegetation, and importance of reference information for ecological restoration of the river.

• 통상정보연구
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• 제13권2호
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• pp.235-258
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• 2011

우리나라의 경제자유구역은 2003년 인천, 부산 진해, 광양만을 지정하여 운영해 오다 2008년 황해, 새만금 군산, 대구 경북의 3개 지역을 추가로 지정하여 총 6개의 경제자유구역을 운영하고 있다. 경제자유구역은 무역의존도가 높은 우리나라에서 새로운 경제성장의 견인차 역할을 수행할 수 있는 제도라 할 수 있다. 그러나, 현재의 경제자유구역 운영방식으로는 당초의 목적을 달성하는데 여러 가지의 문제점을 낳고 있다. 이에 본 연구는 경제자유구역의 운영실태 분석을 통하여 향후 우리나라 경제자유구역의 성공적 운영을 위한 방안을 제시하고자 한다. 첫째, 외국자본유치를 위한 소프트웨어 경쟁력을 강화할 필요성이 있다. 현재 우리나라의 경제자유구역은 하드웨어 측면의 정주여건 즉, 토지개발에만 초점을 맞추고 있으며, 경영환경지원은 부족한 실정이다. 따라서 경영환경지원의 획기적인 개선을 통하여 외국자본유치를 위한 활동을 전개해야 할 것이다. 둘째, 각 정제자유구역별 지역 특색에 맞는 투자유치 모델을 새롭게 정립할 필요하다. 현재의 기본구상을 재조정하여 유치산업분야의 중복을 방지하고 나아가 각 경제자유구역별 차별화된 투자유치 전략을 개발해야 한다. 셋째, 경제자유구역청의 독립성과 전문성 강화를 위한 제도적 장치가 개선되어야 한다. 각 경제자유구역청의 전문성과 독립성을 강화하기 위하여 인력구성이나, 운영규정 등에 있어 경제자유구역청의 권한을 대폭 확대하고 이를 견제하고 감시할 수 있는 방향으로 법 개정이 이루어져야 한다.

• 해양환경안전학회지
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• 제20권1호
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• pp.59-70
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• 2014

최근 중국정부는 해양경제개발에 초점을 두고 네 개의 해양경제개발시범구를 산동성, 절강성, 광동성, 복건성에 설정하였다. 등소평의 개혁 개방 정책이후 근래 해양경제개발시범구까지 중국의 해양산업정책은 현존정책을 부분적으로 수정 보완하는 연속적 점진적인 변화과정이었으므로, 본 논문은 이러한 정책변화를 잘 설명할 수 있는 이론모형으로 정책학의 점증주의모형(Incremental Model)을 이론적 틀로 하여, 새 중국 해양산업정책인 해양경제개발시범구 정책의 본질, 그 역사적 형성과정, 현재 집행상황, 이전과 다른 새로운 정책특징과 시사점을 발견함과 함께 미래의 점진적 정책변화도 전망 예측해 보았다. 과거 중국 해양산업정책과 차별화되는 새 정책의 주요 특징으로는 1)첨단산업과 과학기술을 포함하는 새로운 발전모형이라는 점, 2)고도의 민주적 참여가 보장된다는 점, 3)정책목표로 해양경제발전뿐 아니라 안보영토, 환경생태, 과학교육 등의 다양한 목표들도 포괄하고 있다는 점이었다. 향후 우리나라는 중국의 해양경제개발시범구 정책 특징에 대한 올바른 이해를 통하여, 최근 이슈화된 해양경제특구 설정관련 정책구상에서 바람직한 교훈을 얻어야 할 것이다.