• Title/Summary/Keyword: 물리적 교란 평가

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An Evaluation of Shear Strength Parameters$(c,\varphi)$ for Weathering Decomposed Granite Soil (화강풍화토의 전단정수$(c,\varphi)$ 평가)

  • 이문수;이광찬
    • Journal of the Korean Geotechnical Society
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    • v.15 no.2
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    • pp.181-194
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    • 1999
  • Both the chemical components and the physical and mechanical properties of the compacted and undisturbed weathered granite soils were estimated to investigate the influences of the degree of weathering and saturation on the shear strength. The weathered granite soils used in this study were taken from six different sites in Korea. The results showed that the shear strength of weathered granite soil decreased with increasing the degree of weathering and saturation. Under the normal stresses less that 40kPa, the shape of Mohr-Coulomb failure envelope followed curved or hyperbolic relationship and a half of cohesion value obtained by the common shear test was observed. Using the Sueoka's method, the values of CWI were ranged from 21.5 to 31.26 which can be characterized as a completely weathered granite soil. Large decrease in shear strength and remarkable variation in dilatancy were observed in saturated granite soil compared to unsaturated soil. It was also found that the shear strength of undisturbed weathered granite soil of Pungam site can be expressed approximately by the equation of ${(\tau)_{sat}= 1.0(\tau)_{unsat}-12.48}$ and this equation can be extended to the other sites considered in this study.

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Longevity Issues in Swelling Clay as a Buffer Material for a HLW Repository (고준위폐기물처분장 완충재물질로서 팽윤성 점토의 장기건전성과 주요 고려사항)

  • Lee, Jae-Owan;Cho, Won-Jin
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.6 no.1
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    • pp.55-63
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    • 2008
  • A swelling clay should remain physically and chemically stable for a long time to perform its functions as a buffer material of a high-level waste (HLW) repository. The longevity issues in the swelling clay were reviewed to evaluate their importance in the performance of a repository. The review results suggest that an elevated temperature due to decay heat, groundwater chemistry, high pH environment by concrete, organic matter and microbes, radiation, and mechanical disturbance might significantly affect the long-term performance of a swelling clay as a buffer material. This paper will be used as basic informations to design the swelling clay buffer for a HLW repository.

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A Study on the Effect of Collaborative Instruction Between a Teacher Librarian and a Korean Language Teacher on a Middle School Student's Learning Interest and Academic Achievement (사서교사와 국어교사의 협동수업이 중학생의 학습흥미와 학업성취도에 미치는 영향에 대한 연구)

  • Ki, Min-Jin;Song, Gi-Ho
    • Journal of the Korean Society for Library and Information Science
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    • v.47 no.2
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    • pp.123-142
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    • 2013
  • The aim of this study is to find out the impact of collaborative instruction between the teacher librarian and the classroom teacher on learning interest and academic achievement by running Library and Information Life, which is the textbook of information literacy for teacher librarians and the Korean language curriculum for the first grade of middle school through library-based instruction. The result of this study has a positive influence on academic achievement by facilitating learning interest on Korean language classes under coplanning, co-operating and coevaluating in the school library. Therefore, it is important to establish the institutional system for collaborative instruction in order to increase information literacy instruction in the school community. A local school should expand the physical environment and educational equipment of its school library and form a flexible schedule to have enough time for teaching information literacy skills and for using of materials.

Comparative Analysis of Ecological Health Conditions Before and After Ecological Restoration in Changwon Stream and Nam Stream (창원천.남천에서 생태복원 전.후의 생태건강도 비교평가)

  • Kim, Hyun-Jeong;Lee, Sang-Jae;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.43 no.2
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    • pp.307-318
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    • 2010
  • This study was to analyze the ecological conditions, based on physical habitat, chemical, and biological conditions before (2006, 2007) and after ecological restoration (2009) in five sites of Changwon Stream (CS) and six sites of Nam Stream (NS), respectively, and then to compare ecological health between the two period. The analysis of ecological health was based on the multimetric models of Index of Biological Integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) along with water chemistry in the streams. For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. For the evaluations, the survey was conducted in the period of 2006~2007 before the restoration and in 2009 after the restoration by the city. Chemical conditions, based on conductivity, in both streams showed a typical longitudinal declines along the axis of the upstream-to-downstream. There were no significant differences (p>0.05) in water quality between the two periods. Values of IBI in the CS and NS averaged 21.6 and 19.7, respectively, indicating a C grade in the criteria of Ministry of Environment, Korea, and there was no significant differences in the IBI between the two periods. Values of QHEI after the restoration averaged 29.2 and 63.2 in the CS and NS, respectively and the values decreased markedly especially, in the NS (35.3) after the restoration. The habitat disturbance was mainly attributed to destructions (i.e., the narrower width of riparian vegetation and higher substrate exposure by the air) of artificial materials by massive flood in 2009. Overall, our results suggest that the restoration was not effective in the two streams between the two periods, even if the budget was used a lot and that such ecological restoration, not considered the natural disaster, may not effect for the stream restoration.

The cooling effects of a paddy field area during 2006 summer (2006년 여름철 논에 의한 기온저감효과)

  • Kwon, Sung-Il;Kim, Jin-Soo;Park, Jong-Hwa;Oh, Kwang-Young;Song, Chul-Min
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.628-632
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    • 2007
  • 본 연구에서는 2006년 여름철(2006년 7월 15일${\sim}$9월 30일) 동안 서로 다른 토지피복형태(논, 밭, 도시녹지대 및 도시주택지)에서의 기온변화 특성을 비교하여 논에 의한 기온저감 효과를 파악하였다. 혹서기 동안 총 3회(2006년 8월 3일, 11일, 15일)에 걸쳐 논으로부터의 거리에 따라 기온을 실측한 결과, 논으로부터 거리가 멀어짐에 따라 기온이 상승하였으며, 170m 지점에서의 기온은 논 지점보다 14시에는 $2.3^{\circ}C$, 22시에는 $1.8^{\circ}C$, 익일 06시에는 $1.3^{\circ}C$ 높게 나타났다. 혹서기 동안 논, 밭, 녹지대, 주택지에서의 열대야 완화효과를 비교해보면, 논이 열대야를 완화시키는 효과가 가장 큰 것으로 나타났다. $25^{\circ}C$이하로 낮아지는 평균시각은 논이 22.36시, 밭이 24.0시, 녹지대가 2.2시, 주택지가 2.3시로 나타났고, 이 시각으로부터의 평균 지속시간은 논이 7.7시간, 밭이 7.3시간, 녹지대가 4.3시간, 주택지가 1.0시간으로 나타났다. 또한 평균 일최저기온은 논이 $23.1^{\circ}C$로서 밭과는 동일하게 나타났으며, 녹지대보다 $0.9^{\circ}C$, 주택지보다 $3.0^{\circ}C$ 낮게 나타났다. 그러나 논과 밭에서의 기온저감효과는 큰 차이를 보이지 않았는데, 이는 기온저감효과가 식생피복상태에 의해 크게 좌우되기때문으로 생각된다. 본 연구에서는 논과 밭에 의한 기온저감효과의 메커니즘은 파악되지 않았으나, 이는 다양한 논지대 및 밭지대를 대상으로 열수지 특성을 분석함으로써 구명할 수 있을 것으로 생각된다.자로서는 제방 마루의 토지이용 및 식생구조, 하도의 식생유형, 하도주변 토지이용, 하안(bank) 형상 및 구조, 수종 및 구조, 하도 및 하안 특징 및 구조 등으로 선정, 검토하였다. 이상의 하천교란과 관계되는 지표를 선정하여 물리적, 생태적 조사 및 교란평가기법(안)을 개발, 제시하였다.EX>)를 보였으며, 그 중 3명에서는 혈역학적으로 큰 의미가 없는 잔여단락이 있었다. 결론: 급성 심근경색증 후 심실중격 결손은 수술위험도가 높은 질환이지만, 수술 전 대동맥내 풍선펌프를 삽입하고 조기에 심실중격 결손부의 infarct exclusion 술식과 함께 관상동맥우회술을 시행함으로써 만족할 만한 수술 및 중기 결과를 얻을 수 있었다.출물 투여로 저하되었으나 NC군보다는 높게 나타났다. 간 중 중성지질 함량은 참나물 에탄올 추출물 투여 용량에 따른 유의차가 없었으나, 총콜레스테롤 함량은 고용량 병합투여한 HC-PBH군만 유의하게 저하되었다. 혈청 및 간 중의 지질 함량 변화는 정상식이를 급여한 NC군과 NC-PB군 간에는 유의차가 없었다. 따라서 고콜레스테롤식이를 급여하면서 참나물 에탄올 추출물을 병합투여 시에만 지질대사 개선 효과가 있는 것으로 여겨지며, 고용량 병합투여 시 효능이 더 큰 것으로 나타났다. 고콜레스테롤식이로 인한 산화적 스트레스가 고콜레스테롤혈증을 유발하였으며, 이는 참나물 에탄올 추출물에 함유된 항산화물질을 포함한 여러 생리활성물질이 영향을 미친 것으로 사료된다. 이상의 실험 결과에서 참나물 에탄올 추출물은 고콜레스테롤식이로 증가된 총콜레스테롤, LDL-콜레스테롤 및 중성지질 함량은 감소시켰고, HDL-콜레스테롤과 인지질 함량은 증가시킴으로써 지방간 및 동맥경화의 예방과 치료에 효과적일 것으로 판단되어 진다./hr/g$, 섭취 7일중 $8.123\;{\mu}g/hr/

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Applying Evaluation of Soil Erosion Models for Burnt Hillslopes - RUSLE, WEPP and SEMMA (산불사면에 대한 토양침식모형의 적용 평가 - RUSLE, WEPP, SEMMA)

  • Park, Sang Deog;Shin, Seung Sook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.3B
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    • pp.221-232
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    • 2011
  • Applicability of three soil erosion models for burnt hillslopes was evaluated. The models were estimated with the data from plots established after tremendous wildfire occurred in the east coastal region. Soil erosion and surface runoff were simulated by the Water Erosion Prediction Project (WEPP) and the Revised Universal Soil Loss Equation (RUSLE) of application mode for disturbed forest areas and the Soil Erosion Model for Mountain Areas (SEMMA) developed for burnt hillslopes. Simulated sediment yield and surface runoff were compared with the measured those. In maximum value of sediment yield, three models was under-predicted and RUSLE and WEPP had difference of over two times. SEMMA showed the best model response coefficient, determination coefficient and the model efficiency. In application of models to the soil erosion according to the elapsed year after wildfire, all models were underestimated in initial stage disturbed by wildfire. Evaluation of models in this burnt hillslopes was shown the tends to under-predict soil erosion for larger measured values. Although a lot of sediment can be generated in small rainfall event as fine-grained soil of the high water repellency was exposed excessively right after wildfire, this under-prediction was shown that those models have a limit to estimate the weighted factors by wildfire.

A Study on the Minimization of Spatial Error in 3-Demensional Neuronavigator (3차원 영상지원 뇌수술장비의 공간오차 최소화에 관한 연구)

  • 이동준;다영신;이정교
    • Progress in Medical Physics
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    • v.8 no.2
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    • pp.19-26
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    • 1997
  • 3-dimensional Neuronavigator, Viewing Wand(ISG Technologies, Toronto, Cannda) is the surgery aid equipment for real time image (CT or MRI) guided surgery. The assurance of spatial accuracy of this system is important for clinical application. In this study, we have designed the acrylic brain phantom and measured the spatial error with that phantom. The phantom has designed to have capability to simulate image guided surgery. The phantom has 22 vertical rods whose diameters are 5mm and each rods has different length. CT scans were performed by 2.0mm slice and reconstructed for 3-Dimensional analysis. End point of rods can be obtained using reconstructed 3- Dimensional images and they are compared to actual position data. Average deviation was less than 2mm for various situations. Spatial error of Viewing Wand is acceptable in the clinical points of view, while cosmetics of the software needs to be modified to more user friend. Better accuracy can be expected when we apply the mixed fiducial fit registration and surface fit registration method. And even better results can be obtained if registration points distributed even and symetric around the target.

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A Fundamental Study on the Potential of Alkali-Aggregate Reaction according to KS F 2545 and ASTM C 1260 Test Methods (KS F 2545와 ASTM C 1260 시험법에 따른 알칼리골재 잠재가능성에 관한 연구)

  • Baek, Chul-Seoung;Seo, Jun-Hyung;Kim, Young-Jin;Cho, Kye-Hong;Kim, Kun-Ki;Lee, Jin-Young
    • Resources Recycling
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    • v.29 no.2
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    • pp.18-27
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    • 2020
  • Chemical experiment KS F 2545 and Physical experiment ASTM C 1260 has been accomplished to estimate the potential of alkali aggregate. Used for testing aggregate samples are forest aggregate and recycled aggregate which collected in Gangwon province Samcheok and Pyeongchang, Jeollabuk province Gimje and Kochang, and Gyeongsangnam province Goryeong. As the results of chemical experiment confirmed that if silicate rock and carbonate rock are mixed, reduction in alkalinity is increase. So it has been identified that case makes a disturb at the result of alkali aggregate reaction. In 9 out of the 62 aggregate samples check dissolved silica exceeding 100 mmol/ℓ. and mortar bar length increase rate confirmed that 5 of 9 chemical method aggregates were 0.1~0.2% and 2 aggregates were 0.2%. As a result of the alkaline aggregate reaction test using the chemical method and the mortar bar method, the aggregates showing alkali aggregate reaction are sandstone and tuff aggregates. Therefore, Alkali aggregate reaction tests are required to use clastic sedimentary rocks and volcanic pyroclastic rocks aggregates.

Development of Practical Problem-Based Home Economics Teaching.Learning Process Plans by Blended Learning Strategy - Focusing on a Unit 'the Youth and Consumer Life' - (Blended Learning(BL) 전략을 활용한 실천적 문제 중심 가정과 교수 학습 과정안 개발 - '청소년과 소비생활' 단원을 중심으로 -)

  • Lee, Jin-Hee;Chae, Jung-Hyun
    • Journal of Korean Home Economics Education Association
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    • v.20 no.4
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    • pp.19-42
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    • 2008
  • The purpose of this study was to develop practical problem-based home economics teaching.learning process plans about a unit 'the youth and consumer life' of middle school eighth-grade Technology and Home Economics by applying blended learning(BL) strategy. According to ADDIE instructional design model, this study was conducted in the following procedure: analysis, design/development, implementation, and evaluation. In the stage of design and development, the selected unit was converted into a practical problem-based unit, and practical problem-based teaching. learning process plans were designed in detail by using BL strategy. An online study room for practical problem-based home economics instruction grounded in BL strategy was prepared by using Edunet(http://community.edunet4u.net/${\sim}$consumer2). Eight-session lesson plans were mapped out, and study aids for students and materials for teachers were prepared. In the implementation stage, the first-session teaching plans that dealt with a minor question 'what preparations should be made to become a wise consumer' were utilized when instruction was provided to 115 eighth graders who were in three different province, and the other one was in a middle school in the city of Daejeon. The experimental teaching was implemented for two weeks in the following procedure: preliminary program, pre-online learning, main instruction and post- online learning. The preliminary program was carried out in a session in the classroom, and pre-online learning was provided before the main instruction was given in a session in the classroom. After the main instruction was completed, post-online learning was offered. In the evaluation stage, a survey was conducted on all the learners and teachers to find out their opinions and suggestions.

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The analysis of future land use change impacts on runoff characteristics in urbanized watershed using SWAT model (SWAT 모형을 이용한 도시유역 토지이용 변화가 유출특성에 미치는 영향연구)

  • Kim, Sang-Ho;Ha, Rim;Jung, Chung-Gil;Kim, Seong-Joon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.159-159
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    • 2012
  • 유역의 도시화는 지체시간, 첨두유량 및 총 유출량 등 홍수 유출특성 뿐만 아니라 개발행위에 따른 토사유출특성 변화를 초래하는 등 다양한 문제를 유발하고 있다. 또한 인구증가, 산업발달, 교통량 증가로 인한 화석연료의 소비증가로 대기 중의 이산화탄소의 농도가 급증하여 기후변화에도 큰 영향을 미치고 있다. 이러한 지나친 도시화 진행을 억제하고 웰빙과 건강에 대한 관심 증대에 따라 저탄소 녹색사업의 일환으로 도시 녹지조성 계획이 진행되고 있다. 따라서 본 연구에서는 도시하천인 중랑천 ($288km^2$) 유역을 대상으로 도시화 진행에 따른 토지이용 변화가 강우-유출 특성에 미치는 영향을 분석하였다. 이를 위해, 중랑천 유역의 과거 (1975, 1980, 1985, 1990, 1995, 2000) 토지 이용도로부터 각 항목별 면적변화 추이를 분석한 결과, 17.8%의 도시지역 면적 증가가 나타났다. 미래토지이용 예측을 위하여 CLUE-s (Conversion of Land Use change and its Effects) 모델을 이용하였다. 과거 토지이용 변화 특성을 분석하여 토지피복의 변화와 전이 특성값을 결정하였고, 이를 바탕으로 토지면적 시나리오, 변화 제한지역, 회귀식 결과와 토지이용 변화 특성에 따른 CLUE-s 모델을 이용하여 미래 토지이용변화 (2040, 2080) 모의를 실시하였다. 이러한 토지이용 변화에 따른 유출특성변화 모의를 위해, 물리적 기반의 준분포형 강우-유출 모형인 SWAT (Soil and Water Assessment Tool) 모형을 이용하였다. 모형의 적용성 평가를 위해, 매개변수 민감도 분석에 따른 도시유역 최적의 유출관련 매개변수를 선정하고 중랑교 지점의 일별 유출량자료(2000~2009)를 이용하여 보정 및 검증을 실시하였다. SWAT 모형의 검보정 후, 예측된 미래 토지이용도를 적용하여 과거와 현재, 미래 토지이용변화에 따른 유출특성변화를 비교분석하였다.

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