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Rainfall Quantile Estimation using Scaling IDF Curve and Frequency Analysis (스케일링 IDF곡선과 빈도해석을 이용한 확률강우량 추정)

  • Jung, Younghun;Kim, Sunghun;Kim, Hanbeen;Heo, Jun-Haeng
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.436-436
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    • 2017
  • IDF(intensity-duration-frequency) 곡선은 재현기간을 고려하여 수공구조물 설계에 필요한 설계강우량을 산정하는데 사용되고 있다. 국내의 경우 IDF 곡선은 지점빈도해석으로부터 지속기간별로 산정되고 있으며 지속기간별 분포형 선택과 같은 많은 가정으로 인해 불확실성을 내포하고 있다. 본 연구에서는 이러한 극한 강우량의 스케일 특성을 통해 서로 다른 기간에 걸쳐 통계적으로 접근하고자 하였다. 이를 위해 지속기간 24시간의 강우자료로부터 연최대강우량을 추출하여 스케일 특성을 통해 지속기간 24시간 이하 또는 이상의 스케일링(scaling) IDF 곡선을 유도하였다. 본 연구를 위해 k-means 방법으로부터 지역을 구분하여 지역빈도해석을 실시하였고, 기상청 산하의 강우 지점을 미계측 지점으로 가정한 후 하향스케일링(down-scaling)과 상향스케일링(up-scaling)을 적용한 후 지속기간 24시간 이외의 확률강우량을 추정하였으며, 빈도해석 결과와의 비교를 통해 스케일링 IDF 곡선의 적용성을 판단하였다.

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Free Vibrations of Elastica Shaped Arches (Elastica형 아치의 자유진동)

  • Lee, Byoung Koo;Oh, Sang Jin;Lee, Tae Eun;Kim, Gwon Sik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6A
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    • pp.827-833
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    • 2008
  • This paper deals with the free vibrations of elastica shaped arches. The elastica shaped arches are formed by the post-buckled column whose arc length is always constant. The equations governing free, planar vibration of general arch in open literature are modified for applying the free vibrations of elastica shaped arch and solved numerically to obtain frequencies and mode shapes for hinged-hinged, clamped-hinged and clamped-clamped end constraints. The effects of rotatory inertia, rise ratio and slenderness ratio on natural frequencies are presented. The frequencies of elastica shaped arches are greater than those of parabolic shaped ones. Also, typical mode shapes are presented in figures.

Geometrical Nonlinear Analyses of Post-buckled Columns with Variable Cross-section (후좌굴 변단면 기둥의 기하 비선형 해석)

  • Lee, Byoung Koo;Kim, Suk Ki;Lee, Tae Eun;Kim, Gwon Sik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.1A
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    • pp.53-60
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    • 2009
  • This paper deals with the geometrical nonlinear analyses of post-buckled columns with variable cross-section. The objective columns having variable cross-section of the width, depth and square tapers are supported by both hinged ends. By using the Bernoulli-Euler beam theory, differential equations governing the elastica of post-buckled column and their boundary conditions are derived. The solution methods of these differential equations which have two unknown parameters are developed. As the numerical results, equilibrium paths, elasticas and stress resultants of the post-buckled columns are presented. Laboratory scaled experiments were conducted for validating the theories developed in this study.

Augmented Reality Framework for Efficient Access to Schedule Information on Construction Sites (증강현실 기술을 통한 건설 현장에서의 공정 정보 활용도 제고 방안)

  • Lee, Yong-Ju;Kim, Jin-Young;Pham, Hung;Park, Man-Woo
    • Journal of KIBIM
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    • v.10 no.4
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    • pp.60-69
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    • 2020
  • Allowing on-site workers to access information of the construction process can enable task control, data integration, material and resource control. However, in the current practice of the construction industry, the existing methods and scope is quite limited, leading to inefficient management during the construction process. In this research, by adopting cutting edge technologies such as Augmented Reality(AR), digital twins, deep learning and computer vision with wearable AR devices, the authors proposed an AR visualization framework made of virtual components to help on-site workers to obtain information of the construction process with ease of use. Also, this paper investigates wearable AR devices and object detection algorithms, which are critical factors in the proposed framework, to test their suitability.

Evaluation of Heating and Buckling Effects on Inelastic Displacement Responses of Lead-Rubber Bearing Subject to Strong Ground Motions (강진 시 납-고무 면진장치의 비탄성 변위응답에 대한 온도상승 및 좌굴효과의 분석)

  • Yun, Su-Jeong;Hong, Ji-Yeong;Moon, Jiho;Song, Jong-Keol
    • Journal of the Earthquake Engineering Society of Korea
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    • v.23 no.6
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    • pp.289-299
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    • 2019
  • The tendency to use a probabilistic design method rather than a deterministic design method for the design of nuclear power plants (NPPs) will increase because their safety should be considered and strictly controlled in relation to various causes of damage. The distance between a seismically isolated NPP structure and a moat wall is called the clearance to stop. The clearance to stop is obtained from the 90th percentile displacement response of a seismically isolated NPP subject to a beyond design basis earthquake (BDBE) in the probabilistic design method. The purpose of this study is to analyze the effects of heating and buckling effects on the 90th percentile displacement response of a lead-rubber bearing (LRB) subject to a BDBE. The analysis results show that considering the heating and buckling effects to estimate the clearance to stop is conservative in the evaluation of the 90th percentile displacement response. If these two effects are not taken into account in the calculation of the clearance to stop, the underestimation of the clearance to stop causes unexpected damage because of an increase in the collision probability between the moat wall and the seismically isolated NPP.