Bayesian inference for fault based software reliability models given software metrics data

We wish to predict the number of faults N and the time to next failure of a piece of software. Software metrics data are used to estimate the prior mean of N via a Poisson regression model. Given failure time data and a some well known fault based models for interfailure times, we show how to sample the relevant posterior distributions via Gibbs sampling using the package Winbugs. Our approach is illustrated with an example

Bayesian inference for a software reliability model using metrics information.

In this paper, we are concerned with predicting the number of faults N and the time to next failure of a piece of software. Information in the form of software metrics data is used to estimate the prior distribution of N via a Poisson regression model. Given failure time data, and a well known model for software failures, we show how to sample the posterior distribution using Gibbs sampling, as implemented in the package "WinBugs". The approach is illustrated with a practical example

Using weibull mixture distributions to model heterogeneous survival data

In this article we use Bayesian methods to fit a Weibull mixture model with an unknown number of components to possibly right censored survival data. This is done using the recently developed, birth-death MCMC algorithm. We also show how to estimate the survivor function and the expected hazard rate from the MCMA output

La invalidez de los actos administrativos

El objeto de estudio del presente trabajo es la “Invalidez de los Actos Administrativos”, para ello he creído necesario empezar analizando, primeramente, el “Acto administrativo”: concepto, elementos, clases, etc. Y posteriormente, analizar los “Requisitos de Validez” de los actos administrativos, para a “contrario sensu”, adentrarme ya en el objeto de estudio de este trabajo en cuestión. En cuanto a la invalidez de los actos administrativos, tras una introducción sobre su regulación en España y en países de nuestro entorno en los dos últimos siglos y medio, he analizado las dos grandes figuras o tipos de invalidez en nuestro Derecho Administrativo, sus características y efectos. Otra cuestión importante sobre la invalidez de los actos administrativos es su forma de declaración en vía administrativa y contencioso-administrativa. Será objeto de estudio del presente trabajo. No he querido olvidarme en último término, de la invalidez de los actos administrativos de Derecho comunitario, pues España forma parte de la U.E. y hemos de acatar dicho Derecho, si no queremos ser sancionados. A lo largo del trabajo se expondrán las opiniones y definiciones sobre esta materia de la doctrina, la jurisprudencia del Tribunal Supremo y del Tribunal Constitucional.The object of this work is the “Invalidity of Administrative Acts”, for which I thought it necessary to begin by analysing, first, the “Administrative Act”: concept, elements, classes, etc. And then, to analyze the “Requirements of Validity”, of administrative acts, to “contrary sensu”, to go into the object of study of this work in question. As regards the invalidity of administrative acts, following an introduction on their regulation in Spain and in countries around us in the last two and a half centuries, I have analysed the two great figures or types of invalidity in our Administrative Law and their characteristics and effects. 4 Another important question about the invalidity of the administrative acts is their form of declaration in administrative and contentious-administrative manner. This work shall be examined. I did not want to forget the invalidity of administrative acts of Community law, because Spain is part of the EU and we must abide by that law, but we want to be sanctioned. Throughout the work, opinions and definitions of the doctrine, the case law of the Supreme Court and the Constitutional Court will be set out on this subject.Departamento de Derecho PúblicoGrado en Derech

Comparing and calibrating discrepancy measures for Bayesian model selection

Different approaches have been considered in the literatur e for the problem of Bayesian model selection. Recently, a new method was introduced and analys ed in De la Horra (2008) by minimizing the posterior expected discrepancy between the set of data and the Bayesian model, where the chi-square discrepancy was used. In this article, several discrepancy measures are considered and compared by simulation, and it is obtained th at the chi-square discrepancy is reasonable to use. Then, an easy method for calibrating disc repancies is proposed, and the behaviour of this approach is studied on simulated data. Fin ally, a set of real data is analysedPeer Reviewe

Comparing and calibrating discrepancy measures for Bayesian model selection

Abstract Different approaches have been considered in the literature for the problem of Bayesian model selection. Recently, a new method was introduced and analysed in De la Horra MSC: 62F1

Comparing and calibrating discrepancy measures for Bayesian model selection

Different approaches have been considered in the literature for the problem of Bayesian model selection. Recently, a new method was introduced and analysed in De la Horra (2008) by minimizing the posterior expected discrepancy between the set of data and the Bayesian model, where the chi-square discrepancy was used. In this article, several discrepancy measures are considered and compared by simulation, and it is obtained that the chi-square discrepancy is reasonable to use. Then, an easy method for calibrating discrepancies is proposed, and the behaviour of this approach is studied on simulated data. Finally, a set of real data is analysed

Stability and Thermal Properties Study of Metal Chalcogenide-Based Nanofluids for Concentrating Solar Power

Nanofluids are colloidal suspensions of nanomaterials in a fluid which exhibit enhanced thermophysical properties compared to conventional fluids. The addition of nanomaterials to a fluid can increase the thermal conductivity, isobaric-specific heat, diffusivity, and the convective heat transfer coefficient of the original fluid. For this reason, nanofluids have been studied over the last decades in many fields such as biomedicine, industrial cooling, nuclear reactors, and also in solar thermal applications. In this paper, we report the preparation and characterization of nanofluids based on one-dimensional MoS2 and WS2 nanosheets to improve the thermal properties of the heat transfer fluid currently used in concentrating solar plants (CSP). A comparative study of both types of nanofluids was performed for explaining the influence of nanostructure morphologies on nanofluid stability and thermal properties. The nanofluids prepared in this work present a high stability over time and thermal conductivity enhancements of up to 46% for MoS2-based nanofluid and up to 35% for WS2-based nanofluid. These results led to an increase in the efficiency of the solar collectors of 21.3% and 16.8% when the nanofluids based on MoS2 nanowires or WS2 nanosheets were used instead of the typical thermal oil

On First Passage Times in Discrete Skeletons and Uniformized Versions of a Continuous-Time Markov Chain

In this paper, the aim is to study similarities and differences between a continuous-time Markov chain and its uniformized Markov chains and discrete skeletons in terms of first passage times when the taboo subset of states is assumed to be accessible from a class of communicating states. Under the assumption of a finite communicating class, we characterize the first-passage times in terms of either continuous or discrete phase-type random variables. For illustrative purposes, we show how first passage times in uniformized Markov chains and discrete skeletons can be used to approximate the random duration of an outbreak in the SIS epidemic model

Captura fotográfica gigapíxel de obras de arte

La captura gigapíxel es una técnica muy novedosa que está empezando a ser utilizada por importantes museos internacionales como medio de documentación, análisis y divulgación. Esta publicación expone los logros de un proyecto de investigación centrado en documentar y divulgar importantes obras de arte pictóricas del patrimonio valenciano mediante imágenes fotográficas de ultra alta resolución o resolución gigapíxel.En este trabajo se ha utilizado esta metodología para documentar las principales obras del Museo de Bellas Artes de València y otras pertenecientes a la Diputación de València, al Fondo de Arte de la Universitat Politècnica de València y algunas obras de juventud del pintor valenciano Leopoldo García Ramón.Cabezos Bernal, PM.; Rodríguez Navarro, P.; Gil Piqueras, MT.; Cisneros Vivó, JJ.; Gil Gil, C. (2022). Captura fotográfica gigapíxel de obras de arte. Editorial Universitat Politècnica de València. https://doi.org/10.4995/2022612001EDITORIA