Search results for "ESTIMATION"

The cost of headache disorders in Europe: the Eurolight project

2011

Background and purpose:  Headache disorders are very common, but their monetary costs in Europe are unknown. We performed the first comprehensive estimation of how economic resources are lost to headache in Europe. Methods:  From November 2008 to August 2009, a cross-sectional survey was conducted in eight countries representing 55% of the adult EU population. Participation rates varied between 11% and 59%. In total, 8412 questionnaires contributed to this analysis. Using bottom-up methodology, we estimated direct (medications, outpatient health care, hospitalization and investigations) and indirect (work absenteeism and reduced productivity at work) annual per-person costs. Prevalence data…

Pain estimation: Asking the right questions

2009

Comparison of Causality Network Estimation in the Sensor and Source Space: Simulation and Application on EEG

2021

The usage of methods for the estimation of the true underlying connectivity among the observed variables of a system is increasing, especially in the domain of neuroscience. Granger causality and similar concepts are employed for the estimation of the brain network from electroencephalogram (EEG) data. Also source localization techniques, such as the standardized low resolution electromagnetic tomography (sLORETA), are widely used for obtaining more reliable data in the source space. In this work, connectivity structures are estimated in the sensor and in the source space making use of the sLORETA transformation for simulated and for EEG data with episodes of spontaneous epileptiform discha…

Researching a Capacity Model for Multilane Roundabouts with Negotiation of the Right-of-Way between Antagonist Traffic Flows

2012

This article summarizes a research program designed to assess operating conditions through capacity estimation at not-conventional roundabouts characterized by a central island with a large diameter and by two (or more) entering and circulating lanes. Although giving priority to vehicles on circulatory roadway is the nominal operating rule, on-field observations highlighted that in some infrastructural schemes of the type considered in this research drivers negotiate the right-of-way according to a consensus pattern that alternates between antagonist traffic flows, similarly to that observed at all-way-stop-controlled intersections. Considering the peculiarity of the way of working at round…

Estimation of ordered response models with sample selection

2011

We introduce two new Stata commands for the estimation of an ordered response model with sample selection. The opsel command uses a standard maximum-likelihood approach to fit a parametric specification of the model where errors are assumed to follow a bivariate Gaussian distribution. The snpopsel command uses the semi-nonparametric approach of Gallant and Nychka (1987, Econometrica 55: 363–390) to fit a semiparametric specification of the model where the bivariate density function of the errors is approximated by a Hermite polynomial expansion. The snpopsel command extends the set of Stata routines for semi-nonparametric estimation of discrete response models. Compared to the other semi-n…

Robust Estimation of Infection Fatality Rates during the Early Phase of a Pandemic

2020

AbstractDuring a pandemic, robust estimation of case fatality rates (CFRs) is essential to plan and control suppression and mitigation strategies. At present, estimates for the CFR of COVID-19 caused by SARS-CoV-2 infection vary considerably. Expert consensus of 0.1–1% covers in practical terms a range from normal seasonable Influenza to Spanish Influenza. In the following, I deduce a formula for an adjusted Infection Fatality Rate (IFR) to assess mortality in a period following a positive test adjusted for selection bias.Official datasets on cases and deaths were combined with data sets on number of tests. After data curation and quality control, a total of IFR (n=819) was calculated for 2…

Analysis of the Relationship Between Context and Solution Plan in Modelling Tasks Involving Estimations

2021

In this chapter we analyse students’ written solution plan of a sequence of modelling tasks involving estimations. Our research objective is to statistically analyse whether there is a relation between the solution plan and the characteristics of the context of the real estimation task. From previous work, we have identified some task variables that are directly related to the context. In this study we have designed a sequence of modelling tasks and we have analysed the productions of N = 224 Spanish pre-service primary school teachers. The results show that there is a relationship between the variables of the task and the solution plan used by the students in each case. From the results of…

Exponential smoothing with covariates applied to electricity demand forecast

2013

Exponential smoothing methods are widely used as forecasting techniques in industry and business. Their usual formulation, however, does not allow covariates to be used for introducing extra information into the forecasting process. In this paper, we analyse an extension of the exponential smoothing formulation that allows the use of covariates and the joint estimation of all the unknowns in the model, which improves the forecasting results. The whole procedure is detailed with a real example on forecasting the daily demand for electricity in Spain. The time series of daily electricity demand contains two seasonal patterns: here the within-week seasonal cycle is modelled as usual in exponen…

Socioemotional characteristics of minors in foster care: A comparison between the estimation of parents, teachers and children

2013

Abstract During the child's first few years, it's of fundamental importance the presence of a strong emotional base as long as it creates the possibility to open themselves to physical and social world with confidence, and as it acts as a facilitator of cognitive development. For this reason, if the family cannot ensure such base, social services are forced to resort to foster care, a resource that has a lot of difficulties, leading to different implications in the development of the child and of the foster family. It is therefore important to analyze in depth the socio-emotional variables that characterize children who are in a situation of foster care in order to provide adequate assistan…

Promoting mathematical skills using the instructive program Kriging

2011

Geostatistics was developed in mining for the grade estimation problems of ore deposits, nowadays; it is the most popular method for the interpolation and estimation problems. Methodological consideration about its interpolator, the Kriging, is presented in this paper. For geosciences engineering and other students in general is important to take in advance interpolation methods. This methodology is coming from natural phenomenon, where it is very difficult or even impossible to build deterministic models, only it is possible to describing the behavior from fragmented information of the problem studied. The characterization of the spatial variables using geostatistics has, in general, two m…