• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4146-4158
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• 2022

Ultra-high performance concrete (UHPC) has been widely utilized in military and civil protective structures to resist intensive loadings attributed to its excellent properties, e.g., high tensile/compressive strength, high dynamic toughness and impact resistance. At present, aiming to improve the defects of the traditional vertical concrete cask (VCC), i.e., the external storage facility of spent fuel, with normal strength concrete (NSC) shield, e.g., heavy weight and difficult to fabricate/transform, the feasibility of UHPC applied in the shield of VCC is numerically examined considering its high radiation and corrosion resistance. Firstly, the finite element (FE) analyses approach and material model parameters of NSC and UHPC are verified based on the 1/3 scaled VCC tip-over test and drop hammer test on UHPC members, respectively. Then, the refined FE model of prototypical VCC is established and utilized to examine its dynamic behaviors and damage distribution in accidental tip-over and end-drop events, in which the various influential factors, e.g., UHPC shield thickness, concrete ground thickness, and sealing methods of steel container are considered. In conclusion, by quantitatively evaluating the safety of VCC in terms of the shield damage and vibrations, it is found that adopting the 300 mm-thick UHPC shield instead of the conventional 650 mm-thick NSC shield can reduce about 1/3 of the total weight of VCC, i.e., about 50 t, and 37% floor space, as well as guarantee the structural integrity of VCC during the accidental drop simultaneously. Besides, based on the parametric analyses, the thickness of concrete ground in the VCC storage site is recommended as less than 500 mm, and the welded connection is recommended for the sealing method of steel containers.

• 한국습지학회지
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• 제25권4호
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• pp.345-352
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• 2023

최근 전 세계적으로 겨울철 자연재해인 대설 재해 위험이 커지고 있다. 대한민국 강설의 특징은 지역별 차이가 있는 것이 특징으로, 대설 피해를 줄이기 위한 연구가 많이 진행되고 있으나, 지역별 특성을 반영하지 못한 연구 결과가 제시되고 있다. 본 연구에서는 대한민국의 대설 취약성 평가를 실시하기 위해 PSR 방법과 DPSIR 방법을 사용하였고, 평가 결과 두 가지 평가 방법을 비교하여 신뢰할 수 있는 대설 위험지역을 제시하고자 하였다. PSR 방법은 압력지수, 상태지수, 반응지수로 구분되며, DPSIR 방법은 추진력, 압력, 상태, 영향, 대책 지수로 구분된다. 각 지표에 해당하는 데이터를 수집하고, 엔트로피 가중치 산정방법을 이용하여 가중치를 계산하여 우리나라 전 지역의 대설 취약성 지수를 산출하였다. 최근 2018년부터 2022년까지 대한민국의 대설 피해를 기준으로 PSR과 DPSIR 방법을 이용하여 산출한 지수를 비교한 결과 DPSIR 방법을 이용하여 산출된 취약성 지수가 더 신뢰할 수 있는 결과를 보였다. 본 연구의 결과 대설 피해 발생 시 대설 취약성 지수가 높은 지역을 선제적으로 대비할 수 있고, 효율적인 제설대응체계를 구축할 수 있을 것으로 기대된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.1472-1477
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• 2009

매립지반이 주로 사질토로 구성되어 있거나 호박돌을 많이 함유하고 있는 지반이나 쓰레기 매립지반에서는 시공속도가 매우 빠르고 경제적 측면을 고려한 동다짐공법이 많이 적용되고 있다. 본 연구에서는 대구서부화물역 건설공사의 쓰레기 매립층에 적용된 동다짐공법에 대하여 지반개량효과를 분석하였다. 그 결과 중추낙하다짐 적용구간에 N치는 6.5/30에서 22.5/30으로 약 349% 증가하였다. 다짐전과 후의 지반고 측정결과 중추낙하다짐공법 적용구간은 0.706~1.729m가 침하되었다. 중추낙하다짐에 의한 $\alpha$값은 0.25~0.48로 폐기물층에 대한 일본토질공학회(1987)의 연구결과(0.3~0.5) 및 광산폐기물에 대한 Lukas(1986)의 연구결과(0.35~0.4)와 유사한 범위를 보이고 있다.

• 한국의류학회지
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• 제35권12호
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• pp.1454-1465
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• 2011

Menswear body types are often labeled on garments (to indicate how the garments are designed to fit) with indicators of a size category such as regular, portly, and stout, athletic, or big and tall. A drop (relationships between the chest and waist girths) is related to the fit of a tailored suit. However, current standards are not designed for various drops or body types. There is not enough information of categorizing men's body shapes for the apparel sizing systems. In this article, a set of men's data from SizeUSA sizing survey was analyzed to investigate men's body shapes and drops. Factor analysis and a cluster analysis method were used to categorize men's body shapes. In the results, twenty-five variables were selected through the factor analysis and found four factors: girth factor, height factor, torso girth factor, and slope degree factor. According to the factor and cluster analysis, various body shapes were found: Slim Shape (SS - tall ectomorphy), Heavy Shape (HS - athletic, big & tall, endomorphy and mesomorphy), Slant Inverted Triangle Shape (SITS - regular, slight ectomorphy and slight mesomorphy weight range from normal to slightly overweight), Short Round Top Shape (SRTS - portly and stout, endomorphy). Body shapes were related to fitting categories. SS and HS were related to big & tall fitting category. SITS was related to regular. SRTS was related to portly and stout. Shape 1 (31%) and Shape 2 (26%) were related to current big & tall category. Shape 3 (34%) were related to regular. Shape 4 (9%) were in portly and stout category. ASTM D 6240 standard was the only available standard that presented a regular fitting category. Various drops were found within a same chest size group; however, this study revealed great variances of drops by body shape.