62 documents found, page 1 of 7
Aggregation in Ill-Conditioned Regression Models: A Comparison with Entropy-Bas...
Tavares, Ana Helena; Silva, Ana; Freitas, Tiago; Costa, Maria; Macedo, Pedro; Costa, Rui A. daDespite the advances on data analysis methodologies in the last decades, most of the traditional regression methods cannot be directly applied to large-scale data. Although aggregation methods are especially designed to deal with large-scale data, their performance may be strongly reduced in ill-conditioned problems (due to collinearity issues). This work compares the performance of a recent approach based on n...
Comparison of feature selection methods: modelling COPD outcomes
Cabral, Jorge; Macedo, Pedro; Marques, Alda; Afreixo, VeraSelecting features associated with patient-centered outcomes is of major relevance yet the importance given depends on the method. We aimed to compare stepwise selection, least absolute shrinkage and selection operator, random forest, Boruta, extreme gradient boosting and generalized maximum entropy estimation and suggest an aggregated evaluation. We also aimed to describe outcomes in people with chronic obstru...
A two-stage maximum entropy approach for time series regression
Macedo, PedroThe maximum entropy bootstrap for time series is a technique that creates a large number of replicates, as elements of an ensemble, for inference purposes, which satisfies the ergodic and the central limit theorems. As an alternative to the use of traditional techniques, this work proposes generalized maximum entropy for the estimation of parameters in all the replicated models. An empirical application and a s...
Global temperature and carbon dioxide nexus: evidence from a maximum entropy ap...
Macedo, Pedro; Madaleno, MaraThe connection between Earth’s global temperature and carbon dioxide (CO2) emissions is one of the highest challenges in climate change science since there is some controversy about the real impact of CO2 emissions on the increase of global temperature. This work contributes to the existing literature by analyzing the relationship between CO2 emissions and the Earth’s global temperature for 61 years, providing ...
Introduction
Madaleno, Mara; Macedo, Pedro; Moutinho, VictorEconomic efficiency has received a lot of attention throughout the years. This introductory chapter intends to introduce the topic of the book, discuss the main literature and concepts involved, and provide an overview of the content of each chapter in the book Advanced Mathematical Methods for Economic Efficiency Analysis. This book provides a key instrument for professors, students, academics, researchers, an...
Stochastic frontier analysis with maximum entropy estimation
Macedo, Pedro; Madaleno, Mara; Moutinho, VictorMaximum entropy in the estimation of parameters in stochastic production frontier models could be an attractive procedure in economic efficiency analysis. In this work, the generalized maximum entropy and the generalized cross entropy estimators are reviewed and their implementation in the stochastic frontier analysis is discussed. An application to eco-efficiency analysis of European countries is used to illus...
Crossing non-parametric and parametric techniques for measuring the efficiency:...
Rita, Rui; Marques, Vitor; Bárbara, Diogo; Chaves, Inês; Macedo, Pedro; Moutinho, Victor; Pereira, MarianaBenchmarking techniques have been one of the main tools used by National Regulatory Authorities (NRA) to provide reliable information to define the efficiency targets for regulated undertakings. This paper aims to define the operational efficiency of the Portuguese mainland electricity Distribution System Operator (DSO), a monopoly incumbent with more than six million customers. Given the monopolistic nature of...
Time series regression modelling: replication, estimation and aggregation throu...
Duarte, Jorge; Costa, Maria; Macedo, PedroIn today's world of large volumes of data, where the usual statistical estimation methods are commonly inefficient or, more often, impossible to use, aggregation methodologies have emerged as a solution for statistical inference. This work proposes a novel procedure for time series regression modelling, in which maximum entropy and information theory play central roles in the replication of time series, estimat...
Investigating CO2 emissions from aviation in oil producing countries using a tw...
Zanjani, Zeinab; Soares, Isabel; Macedo, PedroThe transportation sector plays a major role in the rapid economic growth of developing countries. Since this sector requires large amounts of fossil energy resources, it has a very important impact on global warming and greenhouse gas emissions. As aviation has a significant contribution to carbon dioxide (CO2) emissions among different type of transportation, there is considerable interest in policies, regula...
Modelling the impact of the disease on people with COPD – a comparison of featu...
Cabral, Jorge Vaz Ramos Rodrigues de; Macedo, Pedro; Marques, Alda; Afreixo, VeraLockdown due to The COVID-19 pandemic is likely to have influenced the daily life of people with chronic obstructive pulmonary disease. Criteria to choose the most appropriate methods to select features in datasets are unclear. We aimed to compare feature selection methods and describe the effect of the COVID-19 lockdown, sociodemographic and clinical features on the impact of the disease on people with COPD.&n...