Search results for "Uncertainty"

Reduction of the uncertainty in the measurements of magnetic fields

2014

The paper deals with magnetic field measurement, 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. For these reasons, if the measurements are performed to assess the exposure of human beings, 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, we propose an approach which, in particular but very typical cases, allows an effective re…

Squeezing induced by spontaneous rotational symmetry breaking

2009

In this communication we study in depth the phenomenon of quadrature squeezing generated via spontaneous rotational symmetry breaking discussed for the first time in [1]. The idea can be put in short as follows. Consider a degenerate optical parametric oscillator (DOPO) tuned to the first family of transverse modes at the signal frequency, and having perfectly spherical mirrors. When pumped above threshold with a Gaussian beam and within a classical description, it is easy to show that a TEM 10 mode with an arbitrary orientation (measured by θ at Fig. 1) emerges at the subharmonic, hence breaking the rotational symmetry of the system in the transverse plane. Quantum effects are then quite i…

Response to “Comment on ‘Comparison and uncertainty evaluation of different calibration protocols and ionization chambers for low-energy surface brac…

2016

Hyper-Entanglement in Time and Frequency

2019

Hyper-entanglement, i.e. entanglement in more than one degree of freedom, enables a multiplicative increase in Hilbert space size. Such systems can be treated as multi-partite even though the number of state particles is not increased, making them highly attractive for applications in high-capacity quantum communications and information processing [1]. Until now, such states have been realized only using combinations of fully independent degrees of freedom, described by commuting operators, such as polarization and optical paths. Time and frequency, in turn, are linked and described by non-commuting operators. Here, using two discrete forms of energy-time entanglement we demonstrate that ti…

Leveraging Uncertainty Estimates to Improve Segmentation Performance in Cardiac MR

2021

In medical image segmentation, several studies have used Bayesian neural networks to segment and quantify the uncertainty of the images. These studies show that there might be an increased epistemic uncertainty in areas where there are semantically and visually challenging pixels. The uncertain areas of the image can be of a great interest as they can possibly indicate the regions of incorrect segmentation. To leverage the uncertainty information, we propose a segmentation model that incorporates the uncertainty into its learning process. Firstly, we generate the uncertainty estimate (sample variance) using Monte-Carlo dropout during training. Then we incorporate it into the loss function t…

1997

We have determined by forced Rayleigh scattering the diffusion coefficients of photo-labeled polystyrene micronetwork spheres (radii ≤ 10 nm) in melts of linear polyvinylmethylether (M W ≤ 40000 g/mol) at temperatures of 20-80°C. An expected slippage of the spheres through the meshes of the entanglement network appears possible but is still within the experimental uncertainty of our results.

Statistical Analysis of a Method to Predict Drug–Polymer Miscibility

2015

In this study, a method proposed to predict drug-polymer miscibility from differential scanning calorimetry measurements was subjected to statistical analysis. The method is relatively fast and inexpensive and has gained popularity as a result of the increasing interest in the formulation of drugs as amorphous solid dispersions. However, it does not include a standard statistical assessment of the experimental uncertainty by means of a confidence interval. In addition, it applies a routine mathematical operation known as "transformation to linearity," which previously has been shown to be subject to a substantial bias. The statistical analysis performed in this present study revealed that t…

Approximate Bayesian Computation for Forecasting in Hydrological models

2018

Approximate Bayesian Computation (ABC) is a statistical tool for handling parameter inference in a range of challenging statistical problems, mostly characterized by an intractable likelihood function. In this paper, we focus on the application of ABC to hydrological models, not as a tool for parametric inference, but as a mechanism for generating probabilistic forecasts. This mechanism is referred as Approximate Bayesian Forecasting (ABF). The abcd water balance model is applied to a case study on Aipe river basin in Columbia to demonstrate the applicability of ABF. The predictivity of the ABF is compared with the predictivity of the MCMC algorithm. The results show that the ABF method as …

Latent Class Model to Test the Preferences Heterogeneity in the Perceived Information by Public Transport Users

2012

The aim of analysis is to understand as not reliable information influence the user behaviour and how much disincentive the public transport use. For this purpose, a Stated Preference Survey has been carried out in order to know the preferences of public transport users related to information needs and uncertainty on the information provided by Advanced Traveller Information System (ATIS). The perceived uncertainty is defined as the information accuracy. In our study, it was considered the difference between forecasted or scheduled waiting time at the bus stop and/or metro station provided by ATIS, and experienced one by user, to catch the bus and/or metro respectively. A questionnaire has …

Prenatal diagnosis of cerebral malformation with an uncertain prognosis: a study concerning couple's information and consequences on pregnancy.

2004

Abstract Fetal ultrasound (FU) is used during almost all pregnancies and makes a large contribution to the identification of fetal malformation. It is particularly difficult to announce a malformation, particularly those affecting the brain, because there are often doubts concerning both the diagnosis and the prognosis. Aim. – The aim of this study was to analyze how imaging for prenatal screening is organized and how couples are managed and supported. We concentrated on the procedures used to inform couples: content, method of delivery and consequences. Method. –: Study amongst large multidisciplinary centers in Paris and the Paris region, by semi-directed interviews using a questionnaire.…