• Title/Summary/Keyword: Probability plotting position

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Comparison on Probability Plot Correlation Coefficient Test Considering Skewness of Sample for the GEV Distribution (표본자료의 왜곡도 영향을 고려한 GEV 분포의 확률도시 상관계수 검정방법 비교 검토)

  • Ahn, Hyunjun;Shin, Hongjoon;Kim, Sooyoung;Heo, Jun-Haeng
    • Journal of Korea Water Resources Association
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    • v.47 no.2
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    • pp.161-170
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    • 2014
  • It is important to estimate an appropriate quantile for design of hydraulic structure. For this purpose, it is necessary to find the appropriate probability distribution which can represent the sample data well. Probability plot correlation coefficient test as one of goodness-of-fit test, is recently developed and has been known as a simple and powerful method. In this study, probability plot correlation coefficient test statistics using the plotting position considering the coefficients of skewness for the GEV distribution is derived, and represented by the regression equation. Monte-Carlo method is also performed to compare the rejection power between each method. As the results, the probability plot correlation coefficient test which is derived in this study is better than the others. In particular, when sample size is small and distribution has the shape parameter, rejection power of probability plot correlation coefficient test considering the coefficients of skewness is bigger than the others.

Maritime radar display unit based on PC for safe ship navigation

  • Bae, Jin-Ho;Lee, Chong-Hyun;Hwang, Chang-Ku
    • International Journal of Ocean System Engineering
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    • v.1 no.1
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    • pp.52-59
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    • 2011
  • A prototype radar display unit was implemented using inexpensive off-the-shelf components, including a nonlinear estimation algorithm for the target tracking in a clutter environment. Two custom designed boards; an analog signal processing board and a DSP board, can be plugged into an expansion slot of a personal computer (PC) to form a maritime radar display unit. Our system provided all the functionality specified in the International Maritime Organization (IMO) resolution A422(XI). The analog signal processing board was used for A/D conversion as well as rain and sea clutter suppression. The main functions of the DSP board were scan conversion and video overlay operations. A host PC was used to run the tracking algorithm of targets in clutter, using the discrete-time Bayes optimal (nonlinear, and non-Gaussian) estimation method, and the graphic user interface (GUI) software for Automatic Radar Plotting Aid (ARPA). The proposed tracking method recursively found the entire probability density function of the target position and velocity by converting into linear convolution operations.

Flood Frequency Analysis by Wakeby and Kappa Distributions Using L-Moments (Wakeby 및 Kappa 분포의 L-모멘트법에 의한 홍수빈도분석)

  • Maeng, Seung-Jin;Lee, Soon-Hyuk;Lee, Hyeon-Gyu;Ryu, Kyong-Sik;Song, Gi-Heon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.5
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    • pp.17-27
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    • 2006
  • The objective of this study is to induce the design floods by the methodology of L-moment including test of homogeneity, independence and outlier of the data of annual maximum flood flows for 12 water level gaging stations of South Korea. To select appropriate distribution of the data for annual maximum flood flows, the distributions of Wakeby and Kappa are applied and the appropriateness is judged by Kolmogorov-smirnov (K-S) test. The parameters of selected Wakeby and Kappa distributions are calculated by the method of L-moment and the design floods are induced. Through the comparative analysis using the relative root mean square errors (RRMSE) and relative absolute errors (RAE) of design floods, the result shows that the design floods by Wakeby distribution are closer to the observed data than those obtained by the Kappa distribution.