Search results for "model."
showing 10 items of 23664 documents
Curs d'Econometria: part teòrica
2015
El document conté les transparències usades per il·lustrar i complementar les classes teòriques de l'assignatura Econometria, codi 35.820, que s'imparteix en el Grau d'Administració i Direcció d'Empreses de la Universitat de València. És un curs d'introducció a l'Econometria amb sis unitats temàtiques: 1) Models economètrics i dades econòmiques 2) El model de regressió 3) Propietats i hipòtesis en el model de regressió 4) Contrastament de hipòtesis en el model de regressió múltiple 5) Anàlisi de regressió múltiple amb informació qualitativa 6) Incompliment de les hipòtesis bàsiques
The model of governance of the professional football sector in Italy: a critical analysis
2012
The current model of governance of football in Italy has been formally followed by the clubs, but does not effectively address the manifestation of problems such as illegal betting or match fixing. By proposing a taxonomy of pathologies to which professional football is exposed, we highlight some gaps for the identification of tools and procedures useful for the reorientation of club management towards the satisfaction of sporting, economic, social and communicative dimensions.
Consistency of Independent Component Analysis for FMRI
2021
Background Independent component analysis (ICA) has been widely used for blind source separation in the field of medical imaging. However, despite of previous substantial efforts, the stability of ICA components remains a critical issue which has not been adequately addressed, despite numerous previous efforts. Most critical is the inconsistency of some of the extracted components when ICA is run with different model orders (MOs). New Method In this study, a novel method of determining the consistency of component analysis (CoCA) is proposed to evaluate the consistency of extracted components with different model orders. In the method, “consistent components” (CCs) are defined as those whic…
Tensor clustering on outer-product of coefficient and component matrices of independent component analysis for reliable functional magnetic resonance…
2019
Background. Stability of spatial components is frequently used as a post-hoc selection criteria for choosing the dimensionality of an independent component analysis (ICA) of functional magnetic resonance imaging (fMRI) data. Although the stability of the ICA temporal courses differs from that of spatial components, temporal stability has not been considered during dimensionality decisions. New method. The current study aims to (1) develop an algorithm to incorporate temporal course stability into dimensionality selection and (2) test the impact of temporal course on the stability of the ICA decomposition of fMRI data via tensor clustering. Resting state fMRI data were analyzed with two popu…
Ecologists overestimate the importance of predictor variables in model averaging: a plea for cautious interpretations.
2014
Abstract: Information-theory procedures are powerful tools for multimodel inference and are now standard methods in ecology. When performing model averaging on a given set of models, the importance of a predictor variable is commonly estimated by summing the weights of models where the variable appears, the so-called sum of weights (SW). However, SWs have received little methodological attention and are frequently misinterpreted. We assessed the reliability of SW by performing model selection and averaging on simulated data sets including variables strongly and weakly correlated to the response variable and a variable unrelated to the response. Our aim was to investigate how useful SWs are …
Model selection procedure for mixture hidden Markov models
2021
This paper proposes a model selection procedure to identify the number of clusters and hidden states in discrete Mixture Hidden Markov models (MHMMs). The model selection is based on a step-wise approach that uses, as score, information criteria and an entropy criterion. By means of a simulation study, we show that our procedure performs better than classical model selection methods in identifying the correct number of clusters and hidden states or an approximation of them
Clickstream Data Analysis: A Clustering Approach Based on Mixture Hidden Markov Models
2023
Nowadays, the availability of devices such as laptops and cell phones enables one to browse the web at any time and place. As a consequence, a company needs to have a website so as to maintain or increase customer loyalty and reach potential new customers. Besides, acting as a virtual point-of-sale, the company portal allows it to obtain insights on potential customers through clickstream data, web generated data that track users accesses and activities in websites. However, these data are not easy to handle as they are complex, unstructured and limited by lack of clear information about user intentions and goals. Clickstream data analysis is a suitable tool for managing the complexity of t…
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…
A model of microbiological monitoring for prevention of H.A.I. in a Burns Centre.
1995
Wartość informacji w systemie informacyjnym w ocenie jej jakości
2018
Celem artykułu jest ustalenie, w jakim zakresie i w jaki sposób należy dokonywać ewaluacji wartości informacji dostępnej w systemie informacyjnym podczas oceny jej jakości. Taka ocena, zwłaszcza dla systemów działających w Internecie, jest bezwzględnie konieczna z powodu nieustannego, bardzo szybkiego powiększania się dostępnych tam zasobów informacji, ponoszenia zbędnych kosztów ekonomicznych ich złej jakości oraz związanych z tym nowych, niekorzystnych zjawisk społecznych. Jakość informacji jest kategorią wielowymiarową i wymaga oceny bardzo wielu różnych atrybutów. Czy wśród konceptualnych modeli oceny jakości informacji są takie, które wymagają również dokonywania oceny wartości informa…