• Title/Summary/Keyword: Extreme design value

Search Result 140, Processing Time 0.028 seconds

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
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2011.05a
    • /
    • pp.16-16
    • /
    • 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.

  • PDF

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

  • Kim, Yeong-Min
    • Journal of the Architectural Institute of Korea Structure & Construction
    • /
    • v.35 no.10
    • /
    • pp.191-198
    • /
    • 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.

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

  • Yang, Sook-Hi;Hahn, Soo-Yeon
    • The Research Journal of the Costume Culture
    • /
    • v.14 no.5
    • /
    • pp.739-754
    • /
    • 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.

  • PDF

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

  • Kim, Kyoungmin;Kwon, Hyun-Han;Kwon, Soon-Duck
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.39 no.6
    • /
    • pp.667-673
    • /
    • 2019
  • Global warming may accelerate climate change and may increase disaster caused by strong winds. This research studied a method for a nonstationary frequency analysis considering the linear trend over time. The Bayesian method was used to estimate the posterior distribution of the parameters for the extreme value distribution of the annual maximum wind speed at Jeju Airport. The nonstationary frequency analysis was performed based on the Monte Carlo Markov Chain simulation and the Gibbs sampling. The estimated wind speeds by nonstationary frequency analysis was larger than those by stationary analysis. The conventional frequency analysis procedure assuming stationarity is likely to underestimate the future design wind speed in the region where statistically significant trend exists.

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

  • Jeong, Weon-Mu;Cho, Hong-Yeon;Kim, Gunwoo
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.25 no.4
    • /
    • pp.191-199
    • /
    • 2013
  • It is estimated and analyzed that the design wave height and the confidence interval (hereafter CI) according to the return period using the fourteen-year wave data obtained at Pusan New Port. The functions used in the extreme value analysis are the Gumbel function, the Weibull function, and the Kernel function. The CI of the estimated wave heights was predicted using one of the Monte-Carlo simulation methods, the Bootstrap method. The analysis results of the estimated CI of the design wave height indicate that over 150 years of data is necessary in order to satisfy an approximately ${\pm}$10% CI. Also, estimating the number of practically possible data to be around 25~50, the allowable error was found to be approximately ${\pm}$16~22% for Type I PDF and ${\pm}$18~24% for Type III PDF. Whereas, the Kernel distribution method, a typical non-parametric method, shows that the CI of the method is below 40% in comparison with the CI of the other methods and the estimated design wave height is 1.2~1.6 m lower than that of the other methods.

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

  • Ryoo, Kyong-Sik;Lee, Soon-Hyuk
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.46 no.4
    • /
    • pp.25-36
    • /
    • 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.

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

  • Lee, Soon Hyuk;Maeng, Sung Jin;Ryoo, Kyong Sik
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2004.05b
    • /
    • pp.1103-1106
    • /
    • 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.

  • PDF

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

  • 이순혁;박명근;맹승진;정연수;김동주;류경식
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 1999.10c
    • /
    • pp.479-485
    • /
    • 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.

  • PDF

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

  • Jeong, Weon Mu;Ryu, Kyung-Ho;Cho, Hongyeon
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.27 no.4
    • /
    • pp.274-279
    • /
    • 2015
  • Wave data acquired over eleven years near Sokcho Harbor located in the central area of the east coast were analyzed using spectral method and wave-by-wave analysis method and its major wave characteristics were examined. Significant wave heights were found to be high in winter and low in summer, and peak periods were also found to be long in winter and short in summer. The maximum significant wave height observed was 8.95 m caused by the East Sea twister. The distributional pattern of the significant wave heights and peak periods were both fitted better by Kernel distribution function than by Generalized Gamma distribution function and Generalized Extreme Value distribution function. The wave data were compiled to subdivide the wave height into intervals for each month, and the cumulative occurrence rates of wave heights were calculated to be utilized for the design and construction works in nearby construction works.

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
    • /
    • v.32 no.6
    • /
    • pp.583-600
    • /
    • 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.