• Title, Summary, Keyword: weighted distribution

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On Estimating the Hazard Rate for Samples from Weighted Distributions

  • Ahmad, Ibrahim A.
    • International Journal of Reliability and Applications
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    • v.1 no.2
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    • pp.133-143
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    • 2000
  • Data from weighted distributions appear, among other situations, when some of the data are missing or are damaged, a case that is important in reliability and life testing. The kernel method for hazard rate estimation is discussed for these data where the basic large sample properties are given. As a by product, the basic properties of the kernel estimate of the distribution function for data from weighted distribution are presented.

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Local Sensitivity Analysis using Divergence Measures under Weighted Distribution

  • Chung, Younshik;Dey, Dipak K.
    • Journal of the Korean Statistical Society
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    • v.30 no.3
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    • pp.467-480
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    • 2001
  • This paper considers the use of local $\phi$-divergence measures between posterior distributions under classes of perturbations in order to investigate the inherent robustness of certain classes. The smaller value of the limiting local $\phi$-divergence implies more robustness for the prior or the likelihood. We consider the cases when the likelihood comes form the class of weighted distribution. Two kinds of perturbations are considered for the local sensitivity analysis. In addition, some numerical examples are considered which provide measures of robustness.

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An approximate maximum likelihood estimator in a weighted exponential distribution

  • Lee, Jang-Choon;Lee, Chang-Soo
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.1
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    • pp.219-225
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    • 2012
  • We derive approximate maximum likelihood estimators of two parameters in a weighted exponential distribution, and derive the density function for the ratio Y=(X+Y) of two independent weighted exponential random variables X and Y, and then observe the skewness of the ratio density.

Blank Design for Optimized Thickness Distribution for Axi-symmetric Superplastic Blow Forming (축대칭 초소성 블로성형의 두께분포 최적화를 위한 블랭크 설계)

  • 이정민;홍성석;김용환
    • Transactions of Materials Processing
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    • v.8 no.1
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    • pp.92-100
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    • 1999
  • A procedure is proposed for determining the initial thickness distribution in oder to produce a specified final thickness distribution for the axisymmetrical superplastic blow forming processes. Weighted parameter is introduced to improve the simple ad $d_traction method and the initial blank thickness distribution is obtained by optimizing the weighted parameter. This method is applied to superplastic free bulging process with the uniform thickness distribution of final shape to confirm its validity. The optimum initial blank thickness distributions is obtained from arbitrary axisymmetrical superplastic blow forming processes such as dome, cone and cylindrical cup forming with die contact. It is concluded that the ad $d_traction method with weighted parameter is an effective method for an optimum blank thickness distribution design.esign.

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CONVERGENCE OF WEIGHTED U-EMPIRICAL PROCESSES

  • Park, Hyo-Il;Na, Jong-Hwa
    • Journal of the Korean Statistical Society
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    • v.33 no.4
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    • pp.353-365
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    • 2004
  • In this paper, we define the weighted U-empirical process for simple linear model and show the weak convergence to a Gaussian process under some conditions. Then we illustrate the usage of our result with examples. In the appendix, we derive the variance of the weighted U-empirical distribution function.

Heuristic Process Capability Indices Using Distribution-decomposition Methods (분포분할법을 이용한 휴리스틱 공정능력지수의 비교 분석)

  • Chang, Youngsoon
    • Journal of the Korean Society for Quality Management
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    • v.41 no.2
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    • pp.233-248
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    • 2013
  • Purpose: This study develops heuristic process capability indices (PCIs) using distribution-decomposition methods and evaluates the performances. The heuristic methods decompose the variation of a quality characteristic into upper and lower deviations and adjust the value of the PCIs using decomposed deviations in accordance with the skewness. The weighted variance(WV), new WV(NWV), scaled WV(SWV), and weighted standard deviation(WSD) methods are considered. Methods: The performances of the heuristic PCIs are investigated under the varied situations such as various skewed distributions, sample sizes, and specifications. Results: WV PCI is the best under the normal populations, WSD and SWV PCIs are the best under the low skewed populations, NWV PCI is the best under the moderate and high skewed populations. Conclusion: Comprehensive analysis shows that the NWV method is most adequate for a practical use.

Derivation of Design Floods by the Probability Weighted Moments in the Wakeby Distribution (Wakeby 분포모형의 확률가중모멘트기법에 의한 설계홍수량 유도(수공))

  • 송기헌;이순혁;박종화;맹승진;류경식;지호근
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • pp.352-358
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    • 2000
  • The objective of this study is to derive optimal design floods by the Wakeby distribution using the probability weighted moments. parameters for the Wakeby distribution were estimated by the probability weighted moments for the annual flood flows of the applied watersheds. Design floods obtained by the Wakeby and GEV distributions were compared by the relative mean errors, relative absolute errors and root mean square errors. In general, it has shown that the design floods by the Wakeby distribution using the methods of the probability weighted moments are closer to those of the observed data in comparison with those obtained by the GEV distribution.

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Derivation of Design Floods by the Probability Weighted Moments in the Wakeby Distribution (Wakeby 분포모형의 확률가중모멘트기법에 의한 설계홍수량 유도)

  • 이순혁;송기헌;맹승진;류경식;지호근
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.42 no.6
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    • pp.63-71
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    • 2000
  • The purpose of this study is to derive optimal design floods by the Wakeby distribution model using the probability weighted moments. Parameters for the Wakeby distribution were estimated by the probability weighted moments for the annual flood flows of the applied watersheds. Design floods obtained by the Wakeby and GEV distributions were compared by the relative mean errors, relative absolute errors and root mean square errors. In general, it has shown that the design floods by the Wakeby distribution using the methods of the probability weighted moments are closer to those of the observed data in comparison with those obtained by the GEV distribution.

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Modifications of the Weighted Mack-Wolfe Umbrella Tests for a Generalized Behrens-Fisher Problem

  • Park, Hee Moon
    • Journal of the Korean Society for Quality Management
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    • v.21 no.2
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    • pp.179-193
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    • 1993
  • Modifications of t he weighted Mack-Wolfe tests are proposed for both cases when the peak of umbrella is known and unknown. The modified weighted Mack-Wolfe tests are exactly distribution-free when the continuous populations have the same shape. For the case of peak-known umbrella alternatives, the modified weighted Mack-Wolfe tests remain asymptotically distribution-free when the continuous populations are symmetric, but not necessarily with the same shape. For the case of peak-unknown umbrella alternatives, the maximum of standardized modified weighted Mack-Wolfe tests with peak-known umbrella alternatives was used. The simulation results show that the modified weighted Mack-Wolfe tests are more recommended than the modified Mack-Wolfe tests for various patterns.

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