The application of continuous time Weibull models on discrete unemployment duration data may produce bias in the estimated shape of the hazard rate. The bias can be substantial even for weekly duration data, and it is seriously aggravated if the Weibull model is erroneously mixed with a Gamma distribution for unobserved heterogeneity.

Constant upgrading of Enterprise Resource Planning (ERP) systems is necessary, but can cause new defects. This paper attempts to model the likelihood of defects after completed upgrades with Weibull defect probability density function (PDF). A case study is presented analyzing data of recorded defects obtained for one ERP subsystem. The trends are observed for the value of the parameters releva...

The idea of using kernel functions combined with distributions to propose new has recently been used suggest continuous distributions. This article the Epanechnikov function Weibull distribution produce Epanechnikov-Weibull (EWD). We have presented some properties EWD, like moments, MLEs, reliability analysis functions, Rényi entropy and quantile function. estimated model parameters maximum lik...

In the previous studies a hypothesis was developed from the results by using trivariate Weibull model that the increase in leptin concentrations during the second half of the menstrual cycle may be related to changes in the steroidal milieu during the pre ovulatory period and the luteal phase. The present study was undertaken to test this hypothesis further by examining the effect of treatment ...

Macroporous ceramics exhibit an intrinsic strength variability caused by the random distribution of defects in their structure. However, the precise role of microstructural features, other than pore volume, on reliability is still unknown. Here, we analyze the applicability of the Weibull analysis to unidirectional macroporous yttria-stabilized-zirconia (YSZ) prepared by ice-templating. First, ...

The study of pastures, pests (rabbits and caterpillars) and sheep productivity by Barlow (1987; New Zeal J Ecol 10: 43–55) is reviewed, updated and extended. Pasture growth was modelled as a dynamic process, though sheep and rabbit abundance were not dynamic. The model predicted that there was a parabolic relationship between sheep productivity and sheep stocking rate with the effects of rabbit...

BACKGROUND Various noninvasive liver reserve markers were proposed to indicate the severity of liver damage. However, the role and feasibility of these markers to predict the prognosis of patients with hepatocellular carcinoma (HCC) are unknown. We aimed to identify the prognostic role of the 8 currently used hepatic reserve markers in patients with HCC undergoing transarterial chemoembolizatio...

Foresters and landowners have a growing interest in carbon sequestration and cellulosic biofuels in southern pine forests, and hence need to be able to accurately predict them. To this end, we derived a set of aboveground biomass models using data from 62 small-diameter loblolly pines (Pinus taeda) sampled on the Crossett Experimental Forest in southeastern Arkansas. Of the 25 equations initial...

Based on Kullback-Leibler information we propose a data-driven selector, called GAIC (c) , for choosing parameters of regression splines in nonparametric regression via a stepwise forward/backward knot placement and deletion strategy 1]. This criterion uniies the commonly used information criteria and includes the Akaike information criterion (AIC) 2] and the corrected Akaike information criter...