• 제목/요약/키워드: Extreme design value

검색결과 140건 처리시간 0.022초

The history of high intensity rainfall estimation methods in New Zealand and the latest High Intensity Rainfall Design System (HIRDS.V3)

  • Horrell, Graeme;Pearson, Charles
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2011년도 학술발표회
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    • pp.16-16
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    • 2011
  • Statistics of extreme rainfall play a vital role in engineering practice from the perspective of mitigation and protection of infrastructure and human life from flooding. While flood frequency assessments, based on river flood flow data are preferred, the analysis of rainfall data is often more convenient due to the finer spatial nature of rainfall recording networks, often with longer records, and potentially more easily transferable from site to site. The rainfall frequency analysis as a design tool has developed over the years in New Zealand from Seelye's daily rainfall frequency maps in 1947 to Thompson's web based tool in 2010. This paper will present a history of the development of New Zealand rainfall frequency analysis methods, and the details of the latest method, so that comparisons may in future be made with the development of Korean methods. One of the main findings in the development of methods was new knowledge on the distribution of New Zealand rainfall extremes. The High Intensity Rainfall Design System (HIRDS.V3) method (Thompson, 2011) is based upon a regional rainfall frequency analysis with the following assumptions: $\bullet$ An "index flood" rainfall regional frequency method, using the median annual maximum rainfall as the indexing variable. $\bullet$ A regional dimensionless growth curve based on the Generalised Extreme Value (GEV), and using goodness of fit test for the GEV, Gumbel (EV1), and Generalised Logistic (GLO) distributions. $\bullet$ Mapping of median annual maximum rainfall and parameters of the regional growth curves, using thin-plate smoothing splines, a $2km\times2km$ grid, L moments statistics, 10 durations from 10 minutes to 72 hours, and a maximum Average Recurrence Interval of 100 years.

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한옥의 내진설계를 위한 비틀림비정형 평가 방안 (An Evaluation Scheme of Torsional Irregularity for Seismic Design of Hanok)

  • 김영민
    • 대한건축학회논문집:구조계
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    • 제35권10호
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    • pp.191-198
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    • 2019
  • In this paper the evaluation scheme for determining torsional irregularity of Hanok has been proposed. The proposed method can evaluate torsional irregularity of Hanok easily only with characteristics of Hanok shapes, arrangement of lateral load resisting frames and their lateral stiffness without time consuming and complicate 3-dimensional structural analysis. The proposed formula is expressed as allowable maximum eccentricity, and torsional irregularity is evaluated by comparing this value with actual eccentricity. The applicability of the proposed scheme was evaluated by applying it to the line shape plan Hanok with two symmetrically arranged walls and the result was expressed by formula and graph. The results showed that the allowable maximum eccentricity is 10% of plan dimension perpendicular to the seismic load when the walls are placed at the extreme end. The proposed formula was expressed as a generalized formula so it can be applied generally to the various plan shape and wall arrangement of Hanok.

현대 패션에 표현된 글래머 룩의 미적 가치 (A Study on the Aesthetic Value of Glamour Look Expressed in Fashion)

  • 양숙희;한수연
    • 복식문화연구
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    • 제14권5호
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    • pp.739-754
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    • 2006
  • Glamour, which stands for attractive physical feature with certain mystique, has been recognized by its superficiality and ephemerality in recent postmodernist aesthetics. The purpose of this study is to provide a comprehensive literature of glamour and to contemplate glamour look, thereby to establish the styles of glamour expressed in fashion. For such purposes, this thesis first provides the study on the glamour in design studies, film studies and feminist theories, and to inquire aesthetic values of glamour look, which has been reflected in fashion. The glamour expressed in the fashion design can be classified into the following six aesthetic values: luxury, excess, masquerade, appropriation, sensuality and decadence. (1) Luxury is an expression of expensiveness, ostentatiousness which can be achieved only after putting in extensive an elaborate handworks. (2) Excess is an expression of bigness, scalelessness or extreme abundance. (3) Masquerade, that is a technique of identity which deal with clothing as a metaphor, is an expression of mysterious attractiveness and theatricality. (4) Appropriation is an expression by way of taking something from different time and space. (5) Sensuality is an expression of indulgence of sexual pleasures. Lastly, (6) decadence implies eroticized violence and demoralization.

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베이지안 기법을 이용한 제주지역 극치풍속의 비정상성 빈도해석 (A Nonstationary Frequency Analysis of Extreme Wind Speed in Jeju using Bayesian Approach)

  • 김경민;권현한;권순덕
    • 대한토목학회논문집
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    • 제39권6호
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    • pp.667-673
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    • 2019
  • 지구 온난화로 인해 기후변화가 가속화되고 이에 따라 강풍에 대한 재해가 늘어날 것으로 판단된다. 이에 본 연구에서는 시간에 따른 선형 경향성을 고려한 비정상성 빈도해석 모형을 구축하기 위한 방법으로 Bayesian 기법을 적용하였다. 그리고 제주공항 지점의 연 최대풍속자료를 이용하여 극치분포 매개변수들의 사후분포를 추정하고 비정상성 빈도해석을 수행하였다. 재현기간 100년 빈도의 풍속을 추정한 결과를 보면, 경향성이 통계적으로 유의하며 이로 인해 비정상성 빈도해석에 의한 기본풍속이 정상성 빈도해석의 기본풍속보다 크게 추정되고 있다. 이처럼 기상자료의 정상성을 가정한 현재의 빈도해석 절차는 경향성이 존재하는 지역의 경우에 미래의 기본풍속을 과소 추정할 가능성이 크다고 판단된다.

한정된 자료로 추정한 설계파고의 신뢰구간 분석 (Analysis of Confidence Interval of Design Wave Height Estimated Using a Finite Number of Data)

  • 정원무;조홍연;김건우
    • 한국해안·해양공학회논문집
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    • 제25권4호
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    • pp.191-199
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    • 2013
  • 부산항 신항에서 측정한 14년 동안의 파랑자료를 이용하여 재현기간에 따른 설계파고와 신뢰구간을 추정 분석하였다. 극치분석에 사용한 함수는 Gumbel 함수와 Weibull 함수, Kernel 함수이며, 각각의 방법으로 추정한 설계파고의 신뢰구간을 Monte-Carlo 모의기법 중의 하나인 Bootstrap 방법으로 추정하였다. 설계파고의 추정 신뢰구간을 분석한 결과, 약 ${\pm}$10% 수준의 신뢰구간을 만족하기 위해서는 150년 이상의 자료가 필요한 것으로 파악되었다. 그리고 실질적으로 가능한 자료의 개수를 25~50개 정도(25~50년 동안의 추정자료)로 간주하는 경우, Type I 분포함수의 경우 허용오차가 ${\pm}$16~22% 정도이며, Type III 분포함수의 경우, ${\pm}$18~24% 정도로 파악되었다. 한편 비모수적 방법에 해당하는 Kernel 분포함수를 이용한 방법은 Type I과 III을 사용한 것에 비해 신뢰구간은 40% 이하 수준으로 우수한 결과를 보이는 반면, 설계파고는 1.2~1.6 m 정도 낮게 추정하는 결과를 보여주고 있다.

Gamma 및 비Gamma군 분포모형에 의한 강우의 지점 및 지역빈도 비교분석 (I) (Comparative Analysis of Regional and At-site Analysis for the Design Rainfall by Gamma and Non-Gamma Family (I))

  • 류경식;이순혁
    • 한국농공학회논문집
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    • 제46권4호
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    • pp.25-36
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    • 2004
  • This study was conducted to derive the design rainfall by the consecutive duration using the at-site frequency analysis. Using the errors, K-S tests and LH-moment ratios, Log Pearson type 3 (LP3) and Generalized Extreme Value (GEV) distributions of Gamma and Non-Gamma Family, respectively were identified as the optimal probability distributions among applied distributions. Parameters of GEV and LP3 distributions were estimated by the method of L and LH-moments and the Indirect method of moments respectively. Design rainfalls following the consecutive duration were derived by at-site frequency analysis using the observed and simulated data resulted from Monte Carlo techniques. Relative root-mean-square error (RRMSE) and relative efficiency (RE) in RRMSE for the design rainfall derived by at-site analysis in the observed and simulated data were computed and compared. It has shown that at-site frequency analysis by GEV distribution using L-moments is confirmed as more reliable than that of GEV and LP3 distributions using LH-moments and Indirect method of moments in view of relative efficiency.

확률분포에 의한 지속기간 및 빈도별 가뭄우량 추정 (Estimation of Drought Rainfall According to Consecutive Duration and Return Period Using Probability Distribution)

  • 이순혁;맹승진;류경식
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2004년도 학술발표회
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    • pp.1103-1106
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    • 2004
  • The objective of this study is to induce the design drought rainfall by the methodology of L-moment including testing homogeneity, independence and outlier of the data of annual minimum monthly rainfall in 57 rainfall stations in Korea in terms of consecutive duration for 1, 2, 4, 6, 9 and 12 months. To select appropriate distribution of the data for annual minimum monthy rainfall by rainfall station, the distribution of generalized extreme value (GEV), generalized logistic (GLO) as well as that of generalized pareto (GPA) are applied and the appropriateness of the applied GEV, GLO, and GPA distribution is judged by L-moment ratio diagram and Kolmogorov-Smirnov (K-S) test. As for the annual minimum monthly rainfall measured by rainfall station and that stimulated by Monte Carlo techniques, the parameters of the appropriately selected GEV and GPA distributions are calculated by the methodology of L-moment and the design drought rainfall is induced. Through the comparative analysis of design drought rainfall induced by GEV and GPA distribution by rainfall station, the optimal design drought rainfall by rainfall station is provided.

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L-모멘트 및 LH-모멘트에 의한 GEV 분포모형의 실계홍수량의 유도 (Derivation of Design Flood by L-Moments and LH-Moments in GEV distributiion)

  • 이순혁;박명근;맹승진;정연수;김동주;류경식
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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    • pp.479-485
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    • 1999
  • This study was conducted to derived design floods by Generalized Extreme Value(GEV) distributiion for the annual maximum series at ten watersheds along Han, Nagdong, Geum , Yeongsan and Seomjin river systems. Adequency for the analysis of flood data used in this study was established by the test of Independence, Homogeneity , detection of Outliers. Coefficient of variation , skewness and kurtosis were calculated by the L-Moment, and LH-Moment ratio respectively. Parameters were estimated by the Method of L-Method of LH-Moment. Design floods obtained by Method of L-Moments and LH-Moments using different methods for plotting positions in GEV distributions and were compared with those obatined using the Method of L-Moments and LH-Moments by the Relative Mean Errors and Realtive Absoulte Errors. It was found that desgin floods derived by the method of L-Moments and LH-Moments using Cunnane plotting position foumula in the GEV distribution are much closer to those of the observed data in comparison with those obtained by methods of L-moments and LH-moments using the other formula for poltting postions from the viewpoint of Relative Mean Errors and Relative Absoulte Errors. In view of the fact that hydraulic structures indcluding dams and levees are generally usiong design floods with the return period of two hundred years or so, design floods derived by LH-Moments are seemed to be more reasonable than those of L-Moments in the GEV distribution.

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속초 연안의 장기 파랑관측 및 분석 (Long-term Wave Monitoring and Analysis Off the Coast of Sokcho)

  • 정원무;류경호;조홍연
    • 한국해안·해양공학회논문집
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    • 제27권4호
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    • pp.274-279
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    • 2015
  • 동해 중부에 위치한 속초항 연안에서 약 11년간 취득한 파랑자료를 스펙트럼법과 파별분석법을 사용하여 분석하고 대표적인 파랑 특성을 검토하였다. 유의파고는 동계에 크고 하계에 작으며, 첨두주기도 동계에 길고 하계에 짧은 특성을 나타내었다. 관측된 최대 유의파고는 8.95 m 였으며 동해선풍에 의하여 발생되었다. 유의파고와 첨두주기 모두 그 분포 형태를 Generalized Gamma 및 Generalized Extreme Value 분포함수보다는 Kernel 분포함수가 보다 잘 재현하였다. 한편, 인근 해역에서의 설계 및 시공에 도움을 줄 수 있도록 파고 자료를 월별 및 파고 구간별로 세분하고 누적출현율을 제시하였다.

Ensemble deep learning-based models to predict the resilient modulus of modified base materials subjected to wet-dry cycles

  • Mahzad Esmaeili-Falak;Reza Sarkhani Benemaran
    • Geomechanics and Engineering
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    • 제32권6호
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    • pp.583-600
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    • 2023
  • The resilient modulus (MR) of various pavement materials plays a significant role in the pavement design by a mechanistic-empirical method. The MR determination is done by experimental tests that need time and money, along with special experimental tools. The present paper suggested a novel hybridized extreme gradient boosting (XGB) structure for forecasting the MR of modified base materials subject to wet-dry cycles. The models were created by various combinations of input variables called deep learning. Input variables consist of the number of W-D cycles (WDC), the ratio of free lime to SAF (CSAFR), the ratio of maximum dry density to the optimum moisture content (DMR), confining pressure (σ3), and deviatoric stress (σd). Two XGB structures were produced for the estimation aims, where determinative variables were optimized by particle swarm optimization (PSO) and black widow optimization algorithm (BWOA). According to the results' description and outputs of Taylor diagram, M1 model with the combination of WDC, CSAFR, DMR, σ3, and σd is recognized as the most suitable model, with R2 and RMSE values of BWOA-XGB for model M1 equal to 0.9991 and 55.19 MPa, respectively. Interestingly, the lowest value of RMSE for literature was at 116.94 MPa, while this study could gain the extremely lower RMSE owned by BWOA-XGB model at 55.198 MPa. At last, the explanations indicate the BWO algorithm's capability in determining the optimal value of XGB determinative parameters in MR prediction procedure.