Recently, several attempts have been made to define new models that extend well-known distributions and at the same time provide great flexibility in modelling real data. We propose a new four-parameter model named the Weibull-power function (WPF) distribution which exhibits bathtub-shaped hazard rate. Some of its statistical properties are obtained including ordinary and incomplete moments, qu...

This paper focuses on the automotive component failure rate detection using Weibull analysis and other survival analysis techniques. Detailed attention is paid to three areas: 1) overall failure rates are described statistically first, and data cleaning and definitions of ‘failed’ and ‘censored’ data within the research time or warranty period are made; 2) Kaplan-Meier life curves and Log-rank ...

In a 2-alternative forced-choice (2AFC) discrimination task, observers choose which of two stimuli has the higher value. The psychometric function for this task gives the probability of a correct response for a given stimulus difference, Δx. This paper proves four theorems about the psychometric function. Assuming the observer applies a transducer and adds noise, Theorem 1 derives a convenient ...

A Monte Carlo method for computing the bias and standard deviation of estimates of the parameters of a psychometric function such as the WeibulllQuick is described. The method, based on Efron's parametric bootstrap, can also be used to estimate confidence intervals for these parameters. The method's ability to predict bias, standard deviation, and confidence intervals is evaluated in two ways. ...

The consequences of Maternal Mortality (MM) cannot be overemphasized. It inhibits population growth resulting into loss of lives among others. This work tends to obtain the maternal mortality rates (MMR) in Nigeria, identify some fitted distributions to MMR and determine which of the distributions best fits the data. A comprehensive Exploratory Data Analysis (EDA) was carried on MM and the MMRs...

Minnesord över Jörgen Weibull.

The purpose of the present study was to evaluate the relationships among three flexural strengths of recent dental ceramics using 3-point and 4-point bending tests and biaxial flexural test. Three brands of porcelain for veneering (d.SIGN, Supper porcelain AAA, Vintage Hallo), two injectable ceramics (Empress 2, OPC 3G), and one castable ceramic (Crys-Cera) were used. Twenty bar-shaped and 10 d...

The statistics of texture operators on natural images are empirically determined to conform to a Weibull process. We explain these findings from the physical principles of fragmentation processes. The Weibull parameters are known to indicate the fractal dimension of the underlying system. Hence, we show the Weibull process to have a physical foundation for describing natural image statistics. K...

Weibull distribution was used to fit tree diameter data collected from 86 sample plots located in Chinese pine stand in Beijing. To estimate the Weibull distribution parameters, three methods [namely maximum likelihood estimation method (MLE), method of moment (MOM) and least-squares regression method (LSM)] were compared and evaluated on the basis of the mean square error (MSE) and sample size...