Search results for " Uncertainty"
showing 10 items of 777 documents
Perception du risque dépendance et demande d'assurance : une analyse à partir de l'enquête PATER
2013
Dans la littérature économique, de nombreux travaux tentent d'expliquer pourquoi les individus s’assurent aussi peu contre la dépendance. Du côté de l’offre, différents freins possibles au développement du marché de l’assurance dépendance ont d’ores et déjà été pointés du doigt par la littérature. Les estimations récentes montrent néanmoins que les limites imputables à l’offre ne suffisent pas à expliquer le faible développement du marché : même si les assurances étaient moins coûteuses et les couvertures proposées plus larges, la majorité des individus ne souscrirait toujours pas d’assurance. Il est donc nécessaire d’aller trouver des explications du côté de la demande d’assurance dépendan…
Accounting for soil parameter uncertainty in a physically based and distributed approach for rainfall-triggered landslides
2016
In this study we propose a probabilistic approach for coupled distributed hydrological-hillslope stability models that accounts for soil parameters uncertainty at basin scale. The geotechnical and soil retention curve parameters are treated as random variables across the basin and theoretical probability distributions of the Factor of Safety (FS) are estimated. The derived distributions are used to obtain the spatio-temporal dynamics of probability of failure, in terms of parameters uncertainty, conditioned to soil moisture dynamics. The framework has been implemented in the tRIBS-VEGGIE (Triangulated Irregular Network (TIN)-based Real-time Integrated Basin Simulator-VEGetation Generator fo…
Uncertainty management in the measurements of low frequency magnetic fields
2014
The paper deals with low-frequency magnetic field measurements carried out by using a broadband and isotropic instrument. These measurements are characterized by very high uncertainty values, which imply a high risk of wrong decisions when there is the need to establish if a site complies or does not comply with specified emission limits. To reduce this risk, we decided to perform the so called “uncertainty management” that is the discipline of optimizing the cost of a measurement versus the uncertainty target. The task is achieved by using the PUMA method that is an iterative technique originally conceived for geometrical and mechanical measurements. The approach is completely based on the…
UNCERTAINTY EVALUATION IN THE LOW-FREQUENCY MAGNETIC FIELD MEASUREMENTS WITH REGARD TO EXPOSURE OF HUMAN BEINGS
2010
The paper deals with low-frequency magnetic field measurements, with regard to exposure of human beings, carried out by using a broadband and isotropic instrument. These measurements are characterized by a very high uncertainty values if compared with the ones usually related to other electrical measurements. These large uncertainty values imply a high risk of wrong decision when there is the need to establish if a site complies or does not comply with a specified emission limits. A reduction of the uncertainty values implies a reduction of the risk. With this aim, in the paper we propose an approach which, in case of fields generated by electric power systems (50 or 60 Hz), allows an effec…
Bayesian semiparametric long memory models for discretized event data
2020
We introduce a new class of semiparametric latent variable models for long memory discretized event data. The proposed methodology is motivated by a study of bird vocalizations in the Amazon rain forest; the timings of vocalizations exhibit self-similarity and long range dependence. This rules out Poisson process based models where the rate function itself is not long range dependent. The proposed class of FRActional Probit (FRAP) models is based on thresholding, a latent process. This latent process is modeled by a smooth Gaussian process and a fractional Brownian motion by assuming an additive structure. We develop a Bayesian approach to inference using Markov chain Monte Carlo and show g…
Unawareness, Priors and Posteriors
2008
Abstract. This note contains first thoughts on awareness of unawareness in a simple dynamic context where a decision situation is repeated over time. The main consequence of increasing awareness is that the model the decision maker uses, and the prior which it contains, becomes richer over time. The decision maker is prepared to this change, and we show that if a projection-consistency axiom is satisfied unawareness does not affect the value of her estimate of a payoff-relevant conditional probability (although it may weaken confidence in such estimate). Probability-zero events however pose a challenge to this axiom, and if that fails, even estimate values will be different if the decision …
Persistent joblessness and fertility intentions
2019
Background: The vast majority of demographic studies have approached and operationalised the notion of economic uncertainty using snapshot indicators. Hence, the complexity and diversity of individuals' employment careers were largely hidden. We posit that the persistence of joblessness - that is, repeated and close spells of joblessness - represents a crucial marker of economic uncertainty in the realm of fertility (intention) research. Objective: We aim to explore the association between persistent joblessness of both members of the couple and women's fertility intentions among those who entered employment at least once in the last five years. Methods: We develop an index of persistent jo…
Integrative Strategies in Mixed Methods Research
2020
Despite the critical role of integration as a methodological concept in mixed methods studies, researchers lack a theory for integrating. In this article, we introduce the concept of integrative strategy by analyzing three mixed methods rehabilitation-related studies. These studies represented an analytical strategy based on a multiperspective stakeholder approach, a theory-bound analytical strategy, and a theory-oriented synthesizing strategy. We define integrative strategy as a process in which the system of relations within the study is explicated and justified in accordance with the research purpose and phenomenon. This article contributes to mixed methods research by providing a novel…
An EEMD Aided Comparison of Time Histories and Its Application in Vehicle Safety
2017
In the context of signal processing, the comparison of time histories is required for different purposes, especially for the model validation of vehicle safety. Most of the existing metrics focus on the mathematical value only. Therefore, they suffer the measuring errors, disturbance, and uncertainties and can hardly achieve a stable result with a clear physical interpretation. This paper proposes a novel scheme of time histories comparison to be used in vehicle safety analysis. More specifically, each signal for comparison is decomposed into a trend signal and several intrinsic mode functions (IMFs) by ensemble empirical mode decomposition. The trend signals reflect the general variation a…
Integrated Urban Water Modeling with Uncertainty Analysis
2005
In the last 20th years, the scientific world has got particular care towards the problems that involve the respect of the environment. According to this point, several researches were developed to describe the phenomena that take place during both wet and dry period and to increase the knowledge in this field. In particular, the attention was addressed towards the problems linked with the pollution of the water body because of the pollution carried by rainfall waters in the urban environment. In order to obtain a good description of the problem, it is important, of course, to analyze both quantity and quality aspects connected with all the transformation phases that characterize the urban w…