18 documents found, page 1 of 2

Evaluating COVID-19 in Portugal: Bootstrap confidence interval

In this paper, we consider a compartmental model to fit the real data of confirmed active cases with COVID-19 in Portugal, from March 2, 2020 until September 10, 2021 in the Primary Care Cluster in Aveiro region, ACES BV, reported to the Public Health Unit. The model includes a deterministic component based on ordinary differential equations and a stochastic component based on bootstrap methods in regression. T...

Seasonal influenza vaccine effectiveness in persons aged 15–64 years: a systema...

Influenza is a respiratory disease caused by the influenza virus, which is highly transmissible in humans. This paper presents a systematic review and meta-analysis of randomized controlled trials (RCTs) and test-negative designs (TNDs) to assess the vaccine effectiveness (VE) of seasonal influenza vaccines (SIVs) in humans aged 15 to 64 years. An electronic search to identify all relevant studies was performed...

Characterization of mental health issues in the region of Aveiro — A retrospect...

Mean value estimation using low size samples extracted from skewed populations

The use of the -statistic in statistical inference procedures is usually restricted to normal populations or to large samples. However, these conditions may not be fulfilled in some situations: the population can be moderate/highly skewed, or the sample size can be small. In this work, we use the Pearson’s system of distributions, namely, type IV distributions to model . By some simulation work, it is shown tha...

Pareto Models for the Energy Released in Earthquakes

In this paper we explore Pareto based distributions to deal with the energy released by the major seisms. This is a relevant problem because great earthquakes can cause heavy losses, both human and material. The standard Pareto distribution, despite being usually well fitted to the data concerning the energy released by seisms, reveals some lack of fit when dealing with the energy released by the great earthqua...

Alternative heavy tailed models in seismology

Great earthquakes are commonly considered as the ones with moment magnitude (Mw ) above or equal to 8.0. Since these earthquakes can destroy entire communities located near the epicentre, the search of physical laws that explain the energy released by them is an important issue. There is a connection between the radiated energy of an earthquake, its magnitude and its seismic moment (M 0). Thence, when fitting a...

The reference method influence on the sensitivity of the Clostridium difficile ...

The use of enzyme immunoassays to screen for toxins A and B produced by Clostridium difficile is a common procedure in algorithms designed for its detection. Moreover, the absence of a unique test capable of providing reliable results at low cost motivates a great discussion about which algorithm is the best. Thus, several studies have evaluated the performance of these enzyme immunoassays. However, all fail to...

Accuracy measures for binary classification based on a quantitative variable

The identification of the right methodology to perform binary classification based on an observed quantitative variable is usually a complex choice. Thus, the use of appropriate accuracy measures is crucial. In fact, the ROC curve reveals a lot of information about the accuracy of the applied methodology for all the possible values of the cut-point. In particular, the integral and partial areas under the ROC cu...

Estimation Through Array-Based Group Tests

Pooling individual samples for batch testing is a common procedure for reducing costs. The recent use of multidimensional array algorithms, due to the emergence of robotic pooling, is an innovative way of pooling. We show that the two-dimensional array-based group tests can provide accurate estimates for the prevalence rate even for situations in which the traditional estimators, applied to one-dimensional arra...

Discrete Compound Tests and Dorfman’s Methodology in the Presence of Misclassif...

Compound tests can be used to save resources for classification or estimation purposes in clinical trials and quality control. Nevertheless, the methodologies that are usually applied are restricted to qualitative group tests. Moreover, when quantitative compound tests are applied the problem is to ascertain whether the amount of some substance of any individual in the group is greater or lower than a prefixed ...