• Tunnel and Underground Space
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• v.9 no.4
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• pp.364-372
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• 1999

In this paper, mechanical characteristics of micro-defects in granitic rock was studied. Crack spacing and length were investigated by scanline survey in specimen of granite. To estimate the direction and distribution of potential microcrack in granite, thin sections were made for three direction of Rift, Grain and Hardway axis of the rock specimen. The density and length of microcrack were investigated quantitatively. Three directions of microcracks are comparatively perpendicular. Crack density varies as direction differs, but crack length doesn't show influence of direction.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.536-541
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• 2010

최근 도시화, 산업화 등으로 인하여 인구 및 도시시설이 밀집되어 자연적 재해 및 인위적 재난에 취약한 구조를 가지고 있으며, 오래된 시가지와 고지대주거지를 중심으로 재난에 무방비한 장소들이 존재한다. 이는 급속한 도시화 과정에서 비롯된 것으로 도시기반시설이 정비되지 않은 상황에서 무질서한 도시팽창이 이루어낸 결과라고 할 수 있다. 따라서 우리나라의 도시화재 발생 위험성을 평가하기 위한 도시화재의 물리적 연소성상 예측모델을 구축하기 위해 건물간격에 따른 유풍시에 개구분출화염의 성상에 대한 실험을 실시하였다.

• KAPE Magazine
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• s.197
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• pp.20-23
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• 2013

• Journal of the Korean GEO-environmental Society
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• v.10 no.1
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• pp.15-23
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• 2009

The aim of this study was an evaluation of closed non-sanitary landfill's stabilization degree and a determination of its an optimal reclamation method. In order to evaluate the stabilization degree, physical compositions of landfill wastes in 21 closed non-sanitary landfills were analyzed. There were 4 major items such as cover soils, organics, combustibles and incombustibles. With respect to the results of physical compositions, it was determined that the waste in 9 sampling sites of closed non-sanitary landfills after 10years of the relief time was not fully stabilized. The closed non-sanitary landfills must be reclaimed as soon as possible. The main material in closed non-sanitary landfills was cover soils and the highest content was 89.96%. Otherwise, the contents in sanitary landfills was small and 9.89~11.12%. Therefore, it was evaluated that the recovered soil by sorting transfer treatment could be reused as on-site cover soils of the reclamating non-sanitary landfills and/or constructing materials.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.150-159
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• 2023

To determine the toxic effects of the mirror carp, Cyprinus carpio nudus on waterborne nitric acid exposure, they were exposed to waterborne nitric acid at 0, 4, 20, 100, 500, and 2,500 mg NO₃^-/L for 96 h. The semi-lethal concentration (LC₅₀) of the scented fish by 96 hours of acute exposure to nitric acid was 1,433.54 mg NO₃^-/L. The physiological changes of waterborne nitric acid exposure on mirror carp were evaluated through hematologic properties, and RBC count showed a significantly decreased (p < 0.05). The change in the ion control ability of the mirror carp according to exposure to waterborne nitric acid was evaluated through the plasma inorganic component, and calcium and magnesium were significantly decreased (p < 0.05) in the plasma inorganic component. The health and stress status of the mirror carp due to exposure to waterborne nitric acid were evaluated through plasma organic ingredients, and the plasma organic component glucose showed a significantly increase (p < 0.05). Changes in liver damage and enzyme activity due to waterborne nitric acid exposure were evaluated through plasma enzyme components, the enzymatic activities of plasma AST, ALT, and ALP were significantly decreased (p < 0.05) in high levels of waterborne nitric acid exposure. The results of the present study suggest that waterborne nitric acid exposure to C. carpio nudus can toxicly affect survival, hematologic properties, and plasma components.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.1
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• pp.61-67
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• 2007

The binocular functional test was performed in test of both accommodation and convergence. The balance of accommodation and convergence was important. Objects were 100 adults in 18-36 years old ages. The used apparatus was vision tester(Shinnippon VT10)and visual chart(Shinnippon CT30). Accommodative lag test by fused cross cylinder were that in case of high 39.0%, in case of low 14.0%. Negative relative accommodation were that in case of high 23.0%, in case of low 38.0%. Positive relative accommodation were that in case of high 29.0%, in case of low 23.0%. In 18% were case of low accommodation.

• Korean Journal of Poultry Science
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• v.45 no.2
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• pp.81-88
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• 2018

The present study investigated effect of supplementation of agricultural byproduct on growth performance and blood parameters of broiler chicken using meta-analysis. Total 11 studies (32 experiments) where broiler feeding trials with agricultural byproducts were included were employed in analysis. All studies were conducted at commercial farm placed in South Korea and under commercial feeding programs. Growth phases were divided into two groups based on slaughter day. For growth performance, body weight, body weight gain, feed intake and feed conversion rate (feed/gain) were investigated. Carcass weight, dressing percentage, liver and spleen weight, blood glucose, total cholesterol and triglyceride, HDL (High density lipoprotein) and LDL (Low density lipoprotein) cholesterol contents in blood were investigated. Body weight of broiler of treatment was significantly increased than the control (P<0.05), regardless of growth phase. However, body weight gain during late growth phase did not show significant difference between control and treatment. Effect evaluated by random effect model on feed intake was not significant. Effect on feed conversion rate during early growth phase was significantly negative (P<0.05). Effects on carcass weight, dressing percentage, liver and spleen weight were not significant in random effect model. Effect on abdominal fat was significantly negative (P<0.05). In blood parameters, significant effects were found at total cholesterol, triglyceride and HDL cholesterol (P<0.05). Effect on HDL cholesterol only was positive effect, and others were negative.

• Radiation Oncology Journal
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• v.7 no.1
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• pp.23-27
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• 1989

Forty-four patients with brain astrocytoma and glioblastoma were rested with surgical resection and postoperative radiation from January 1980 through May 1987, Four patients were lost to follow up, and in 40 patients survival time was evaluable. Three year actuarial survival rate was $66.7\%$ in Grade I and II astrocytoma, $30\%$ in Grade III, and $20.4\%$ in glioblastoma multiforme patients. The prognostic factors affecting survival rate were histologic grade in all cases, age, and total radiation dose in Grade III and glioblastoma.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.137-137
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• 2023

해양쓰레기는 해안의 심미적 가치 저하뿐만 아니라 생태계 파괴, 유령 어업에 따른 수산업 피해 등의 사회적·환경적 문제를 발생시키며, 그중 70% 이상은 육상 기인으로 플라스틱 및 기타 쓰레기가 주를 이루는 해외와 달리 국내의 경우 다량의 초목류를 포함하고 있다. 다양한 부유쓰레기에 대한 기존의 해양쓰레기량 추정의 한계와 하천·하구 쓰레기 수거의 효율화를 위해 해양으로 유입되는 부유쓰레기 방지를 위한 실효성 있는 대책 수립이 필요한 실정이다. 본 연구는 해양 유입 전 하천의 차단시설에 차집된 부유쓰레기의 수거 효율화 및 지속가능한 해양쓰레기 데이터 구축을 위해 AI기반의 기술을 통해 부유쓰레기 성상 분석 기법(Object Detection)과 차집량 분석 기법(Semantic Segmentation)을 활용하였다. 실제와 유사한 데이터 수집을 위해 다양한 하천 환경(정수조, 소하천, 급경사수로)에 대해 탁도(녹조, 유사), 광량, 쓰레기형상, 초목류 함량, 날씨(소하천), 유속(급경사수로) 등의 실험조건에 대하여 해양쓰레기 분류 기준 및 통계를 바탕으로 부유쓰레기 종류 선정하여 학습을 위한 데이터를 수집하였다. 학습 목적에 따라 구분하여 라벨링(Bounding box, Polygon)을 수행하고, 각 분석 기법별 전이학습을 통해 Phase 1(정수조), Phase 2(소하천), Phase 3(급경사수로) 순서로 모델을 고도화하였다. 성상 분석을 위해 YOLO v4를 활용하여 Train, Test DataSet(9:1)을 구성하고 학습 및 평가는 Iteration마다의 mAP, loss 값을 통해 비교하였으며, 학습 Phase에 따라 모델 고도화로 Test Set의 mAP 값이 성상별로 높아짐을 확인하였으며, 차집량 분석을 위해 Unet을 활용하여 Train, Test, Validation DataSet(8.5:1:0.5)을 구성하고 epoch별 IoU(intersection over Union), F1-score, loss 값을 비교하여 정성적, 정량적 평가 모두 Phase 3에서 가장 높은 성능을 확인하였다. 향후 하천 환경에서의 다양한 영양인자별 분석을 통해 주요 영향인자 도출 및 Hyper Parameter 최적화를 통한 모델 고도화로 인해 활용성이 높아질 것으로 판단된다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.28-31
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• 2011

최근 산불과 같은 불티로 인한 2차화재의 발생 비율이 높아지고 있는 추세이다. 그러나 이를 불티로 인한 화재 성상을 CFD로 해석하기 위해서는 불티에 가해지는 유체력을 평가하여야 연소모델을 적용할 수 있다. 따라서 본 연구에서는 기존 풍속에 의한 불티 확산실험의 결과를 토대로 FDS에 적용 할 수 있는 연소모델을 구축하고 위하여 수리 모델 및 수치 해법에 대해 정리하고 이를 FDS 연소모델에 적용을 실시하였다.