• Title/Summary/Keyword: Cumulative Distribution

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ROC Curve for Multivariate Random Variables

  • Hong, Chong Sun
    • Communications for Statistical Applications and Methods
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    • v.20 no.3
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    • pp.169-174
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    • 2013
  • The ROC curve is drawn with two conditional cumulative distribution functions (or survival functions) of the univariate random variable. In this work, we consider joint cumulative distribution functions of k random variables, and suggest a ROC curve for multivariate random variables. With regard to the values on the line, which passes through two mean vectors of dichotomous states, a joint cumulative distribution function can be regarded as a function of the univariate variable. After this function is modified to satisfy the properties of the cumulative distribution function, a ROC curve might be derived; moreover, some illustrative examples are demonstrated.

The difference between two distribution functions

  • Hong, Chong Sun
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.6
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    • pp.1449-1454
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    • 2013
  • There are many methods for measuring the difference between two location parameters. In this paper, statistics are proposed in order to estimate the difference of two location parameters. The statistics are designed not using the means, variances, signs and ranks, but with the cumulative distribution functions. Hence these are measured as the differences in the area between two univariate cumulative distribution functions. It is found that the difference in the area between two empirical cumulative distribution functions is the difference of two sample means, and its integral is also the difference of two population means.

APPROXIMATION TO THE CUMULATIVE NORMAL DISTRIBUTION USING HYPERBOLIC TANGENT BASED FUNCTIONS

  • Yun, Beong-In
    • Journal of the Korean Mathematical Society
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    • v.46 no.6
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    • pp.1267-1276
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    • 2009
  • This paper presents a method for approximation of the standard normal distribution by using hyperbolic tangent based functions. The presented approximate formula for the cumulative distribution depends on one numerical coefficient only, and its accuracy is admissible. Furthermore, in some particular cases, closed forms of inverse formulas are derived. Numerical results of the present method are compared with those of an existing method.

On the comparison of cumulative hazard functions

  • Park, Sangun;Ha, Seung Ah
    • Communications for Statistical Applications and Methods
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    • v.26 no.6
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    • pp.623-633
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    • 2019
  • This paper proposes two distance measures between two cumulative hazard functions that can be obtained by comparing their difference and ratio, respectively. Then we estimate the measures and present goodness of t test statistics. Since the proposed test statistics are expressed in terms of the cumulative hazard functions, we can easily give more weights on earlier (or later) departures in cumulative hazards if we like to place an emphasis on earlier (or later) departures. We also show that these test statistics present comparable performances with other well-known test statistics based on the empirical distribution function for an exponential null distribution. The proposed test statistic is an omnibus test which is applicable to other lots of distributions than an exponential distribution.

A study on estimating background concentration of groundwater for water quality assessment in non-water supply district (상수도 미보급 지역의 지하수 수질상태 평가를 위한 배경농도 산정방법에 관한 연구)

  • Yea, Young-Do;Seo, Yong-Gyo;Kim, Rak-Hyeon;Cho, Dong-Jun;Kim, Kwang-Shik;Cho, Wook-Sang
    • Journal of Korean Society of Water and Wastewater
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    • v.28 no.3
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    • pp.345-358
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    • 2014
  • For introducing the groundwater quality assessment using background concentration of groundwater, several methods had been studied to estimate the background concentration of groundwater and to suggest the background concentration of study area. Some methods such as Box whisker plot, Percentile and Cumulative probability distribution had been adopted to estimate background concentration, and it was evaluated that the Cumulative probability distribution method presents more reasonable background concentration because it can consider the data distribution. So we estimated the background concentration of study area using cumulative probability distribution method. We suggested the background concentration for each hydrogeology respectively in case hydrogeological water quality similarity is very low.

A Probabilistic Analysis for Fatigue Cumulative Damage and Fatigue Life in CFRP Composites Containing a Circular Hole (원공을 가진 CFRP 복합재료의 피로누적손상 및 피로수명에 대한 확률적 해석)

  • 김정규;김도식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.8
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    • pp.1915-1926
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    • 1995
  • The Fatigue characteristics of 8-harness satin woven CFRP composites with a circular hole are experimentally investigated under constant amplitude tension-tension loading. It is found in this study that the fatigue damage accumulation behavior is very random and history-independent, and the fatigue cumulative damage is linearly related with the mean number of cycles to a specified damage state. From these results, it is known that the fatigue characteristics of CFRP composites satisfy the basic assumptions of Markov chain theory and the parameter of Markov chain model can be determined only by mean and variance of fatigue lives. The predicted distribution of the fatigue cumulative damage using Markov chain model shows a good agreement with the test results. For the fatigue life distribution, Markov chain model makes similar accuracy to 2-parameter Weibull distribution function.

Noncentral F-Distribution for an M-ary Phase Shift Keying Wedge-Shaped Region

  • Kim, Jung-Su;Chong, Jong-Wha
    • ETRI Journal
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    • v.31 no.3
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    • pp.345-347
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    • 2009
  • This letter presents an alternative analytical expression for computing the probability of an M-ary phase shift keying (MPSK) wedge-shaped region in an additive white Gaussian noise channel. The expression is represented by the cumulative distribution function of known noncentral F-distribution. Computer simulation results demonstrate the validity of our analytical expression for the exact computation of the symbol error probability of an MPSK system with phase error.

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Optimal Burn-in Time under Cumulative Pro-Rata Replacement Warranty

  • Yun, Won-Young;Lee, Yang-Woo;Chung, Il-Han;Luis Ferreira
    • International Journal of Reliability and Applications
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    • v.2 no.4
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    • pp.241-251
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    • 2001
  • In this paper, optimal bum-in time to minimize the total mean cost, which is the sum of manufacturing cost with burn-in and cumulative warranty-related cost, is obtained. When the products with cumulative pro-rata warranty have high failure rate in the early period (infant mortality period), a burn-in procedure is adopted to eliminate early product failures. After burn-in, the posterior product life distribution and the warranty-related cost are dependent on burn-in time; long burn-in period may reduce the warranty-related cost, but it increases the manufacturing cost. The paper provides a methodology to obtain total mean cost under burn-in and cumulative pro-rata warranty. Property of the optimal burn-in time is analyzed, and numerical examples and sensitivity analysis are studied.

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On scaled cumulative residual Kullback-Leibler information

  • Hwang, Insung;Park, Sangun
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.6
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    • pp.1497-1501
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    • 2013
  • Cumulative residual Kullback-Leibler (CRKL) information is well defined on the empirical distribution function (EDF) and allows us to construct a EDF-based goodness of t test statistic. However, we need to consider a scaled CRKL because CRKL is not scale invariant. In this paper, we consider several criterions for estimating the scale parameter in the scale CRKL and compare the performances of the estimated CRKL in terms of both power and unbiasedness.