• Journal of the Korean Geotechnical Society
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• v.27 no.7
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• pp.47-57
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• 2011

The p-y curve has been used to design pile foundations subjected to lateral loading. Although the p-y curve has a large influence on the pile lateral behavior, p-y curves have not been clearly suggested. In this study, the p-y curve of clay was evaluated for drilled shafts in marine deposits by using 3-dimensional numerical analyses. First, the optimization study was performed to properly determine boundary extent, mesh size, and interface stiffness. The numerical modeling in the study was verified by comparing the calculated and the pile loading test results. Then, the p-y curves of single and group piles were evaluated from the parametric study. The selected parameters were pile diameter, pile Young's modulus and pile head fixed condition for a single pile, and pile spacing for group piles. Finally, the p-multiplier was evaluated by comparing the p-y curves of a single pile and group piles. As a result, the p-multiplier at pile spacing of 3D was 0.83, 0.67 and 0.78 for the front, middle, and back row piles, respectively, and showed values similar to those of O'Neill and Reese (1999). For the pile group with pile spacing larger than 60, the group effect can be ignorable.

• Journal of the Korean Geotechnical Society
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• v.32 no.11
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• pp.5-19
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• 2016

This paper presents the results from three-dimensional finite element (FE) analysis undertaken to provide insight into the lateral behaviors of piled gravity base foundation (GBF) for offshore wind turbine. The piled GBF was originally developed to support the gravity based foundation in very soft clay soil. A GBF is supported by five piles in a cross arrangement to achieve additional vertical bearing capacity. This study considered four different cases including a) single pile, b) three-by-three group pile (with nine piles), c) cross-arrangement group pile (with five piles), and d) piled GBF. All the cases were installed in homogenous soft clay soil with undrained shear strength of 20 kPa. From the numerical results, p-y curves and thus P-multiplier was back-calculated. For the group pile cases, the group effect decreased with increasing the number of piles. Interestingly, for the piled GBF, the P-multipliers showed a unique trend, compared to the group pile cases. This study concluded that the global lateral behaviour of the piled GBF was influenced strongly by the interaction between GBF and contacted soil surface.

• Korean Journal of Ecology and Environment
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• v.54 no.2
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• pp.87-95
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• 2021

Macroinvertebrates in forest streams affect the overall health of other streams in the same water system. In this study, we compared differences in the benthic macroinvertebrate community at two headwater streams located at different latitudes in the southern and northern parts of South Korea. We calculated the community temperature index (CTI), which represents the thermal preferences of the benthic communities. Hierarchical cluster analyses (HCA) were conducted to compare the similarities among sampling sites. In addition, we analyzed the relationship between community composition and environmental and community characteristics using non-metric multidimensional scaling (NMDS). Our results showed that CTI was significantly different between the two regions, indicating that these benthic macroinvertebrate communities have different thermal preferences. These two regions were clearly distinguished from each other in the HCA; furthermore, seasonal differences in benthic community composition were observed within each region. The functional feeding groups present in the benthic macroinvertebrate communities were different even though their habitat was similar.

• Ecology and Resilient Infrastructure
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• v.9 no.1
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• pp.15-23
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• 2022

This study was conducted to investigate in relation to characteristic of macroinvertebrates in conventional and organic paddy fields. The investigation was conducted five times a year for Suwon, Ansung, Boeun, Gunsan, Gimje, Hamyang, divide into conventional paddy fields and organic paddy fields from 2009 to 2011. The macroinvertebrates collected from the surveyed between conventional and organic paddy fields belonged to 84 species, 47 families, 16 orders, and 6 classes in 3 phyla. In the habitat orientied groups, climbers, swimmers and sprawlers were considerably occupied in conventional and organic paddy fields. In relation to the functional feeding groups, predators such as Odonata, Coleoptera, and Hemiptera were only the highest in paddy field ecosystem, regardless of cultivation method. As a result of community stability analysis, orgainc paddy fields has been identified much as species high resistance and resilience to environmental change in paddy field ecosystem. Species belonging to the I groups is considered to be important in organic paddy field such as Sternolophus rufipes, Hydrochara affinis, Helochares nipponicus, which has high mobility. In conclusion, it was found that the introduction of coleoptera as a food source was higher than that of conventional paddy fields in organic paddy field where primary consumers were abundant such as Chironomidae spp. and Dixidae sp..

• Journal of the Korean GEO-environmental Society
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• v.24 no.10
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• pp.51-58
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• 2023

The dynamic behavior of the group piles supporting the superstructure in an earthquake is influenced by different complex dynamic mechanisms by the inertia force of the superstructure and the kinematic force of the ground. In an earthquake, The dynamic p-y curve is used to analyze the dynamic behavior of the pile foundation in consideration of the interaction of the ground, pile foundation, and superstructure due to the inertia force and the kinematic force. Most of the research has been conducted in order to confirm the dynamic p-y curve of the pile foundation by applying to the pile foundation installed on the single layered ground consisting of sand and clay, but the research for the multiple layered ground is insufficient. In this study, 1g shaking table tests were conducted to analyze the effect of the strata ratio of the top and bottom ground of the two layered sandy ground which has different relative densities on the dynamic behavior of group piles supporting the superstructure. The result shows that the maximum acceleration in the ground, the pile cap, and the superstructure increases as the strata ratio increases, and the location of the maximum bending moment of the pile foundation is changed. In addition, it was confirmed that the slope of the dynamic p-y curve of the pile foundation increased and decreased according to the strata ratio.

• The Korean Publising Journal, Monthly
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• s.134
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• pp.20-21
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• 1993

이번 모임이 우리출판계에 던져준 교훈은 중국 출판인들이 자신들의 절박한 사정으로 인해 한국출판계를 '공략'해 들어온다는 표현이 적합할 만큼 '무리한' 요구를 해오는 점과, 단순히 중국의 현재 출판 제작.인쇄 수준이 우리보다 낮다 하여 과소평가하여 소홀히 대응할 경우 예기치못한 상황까지 도래할 수 있다는 점이다.

• 대학교육
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• s.92
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• pp.70-83
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• 1998

대학이나 학술연구의 진흥을 통하여 우리나라의 고유한 학술문화가 발전되고, 세계속의 우리 위상이 제고될 것이다. 21세기 한국의 학술문화를 선진 수준으로 끌어올리기 위해서는 학문의 균형적 발전이 필요한 바, 종합적인 학술진흥 정책 추진이 요구된다. 경제가 아무리 어려워도 과학기술 우선정책으로 인하여 인문.사회과학을 홀대하거나 침체를 외면해서는 안 된다.

• Journal of the Korean hospital association
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• v.34 no.5 s.297
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• pp.55-63
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• 2005

신라천년의 고도로 삼국통일의 대업을 이룩하는데 견인차 역할을 한 화랑도의 함성이 메아리쳤던 경주! 동국대병원. 병원 앞을 흐르는 하천(형산강)엔 새하얀 자태를 뽐내며 백조가 무리지어 한가로이 노닐다 내원객을 반기기라도 하듯 날개짓을 하며, 정문 좌우측 석등은 불교재단 병원의 기품을 더해준다(사무실 부서명칭 푯말도 매우 인상적인 연꽃 엠블렘으로 장식).

• 건강소식
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• v.37 no.2
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• pp.34-37
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• 2013

된장찌개, 상추쌈, 불고기, 갈치조림 등 맛깔스럽게 밥상이 차려져 있다. 군침을 흘리며 냉큼 다가앉아 음식을 한입 넣는 순간, 염분기가 전혀 없는 맹탕의 맛이라면 첫마디가 어떻게 나올까? '무슨 맛이 이래?'라는 말이 절로 나올 것이다. 아무리 갖은 양념을 하여도 염분기가 없다면 입맛은 싹 사라질 것이다.

• 건강소식
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• v.37 no.3
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• pp.30-31
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• 2013

봄철 무리한 운동으로 발생하기 쉬운 어깨 통증. 어깨 통증을 단순 근육통으로 여기고 방치하면 일상생활이 어려울 수도 있다. 관절와순 파열과 회전근개 파열이 대표적이다. 관절와순 파열은 일반적으로 스포츠 손상이 원인으로 주로 젊은층에게 흔하며, 회전근개 파열은 퇴행성 변화 및 외상이 원인으로 중 장년층에서 흔히 발생한다.