Planeamento experimental usando ANOVA de 1 e 2 fatores com R: uma breve abordagem prática

Documento pedagógico sobre planeamento de experiências recorrendo ao software aberto R. A abordagem é baseada em exemplos práticos e descreve a elaboração e execução de testes ANOVA de 1 e 2 fatores, e testes post-hoc subsequentes. São também discutidas algumas alternativas não-paramétricas à ANOVA.Planeamento experimental com o software aberto R: ANOVA de 1 e 2 fatores.N/

Solvers de programação linear

Documento pedagógico sobre uso de solvers comuns na resolução de problemas de programação matemática (programação linear, inteira, mista e não-linear). Com exemplos.Documento sobre uso de solvers (Excel, R, LP Solve) para resolução de problemas de Programação Matemática.N/

K-theory for Cuntz-Krieger algebras arising from real quadratic maps

We compute the $K$-groups for the Cuntz-Krieger algebras $\mathcal{O}_{A_{\mathcal{K}(f_{\mu})}}$, where $A_{\mathcal{K}(f_{\mu})}$ is the Markov transition matrix arising from the \textit{kneading sequence }$\mathcal{K} (f_{\mu})$ of the one-parameter family of real quadratic maps $f_{\mu}$.Comment: 8 page

Visualização de dados e testes de hipóteses com R : uma breve abordagem prática

Documento pedagógico contendo uma breve introdução prática à visualização de dados e testes de hipóteses recorrendo ao software aberto R. A abordagem é baseada em dois exemplos de variáveis estatísticas de diferentes naturezas (uma discreta, outra contínua). Inclui também indicações para a instalação do R.Introdução prática à visualização de dados e testes de hipóteses com o software aberto R.N/

An analysis of the possible causes of product market malfunctioning in the EU: First results for manufacturing and service sectors

Within the context of the follow-up to the Single Market Review, the European Commission has screened EU manufacturing and service sectors for problems of market malfunctioning. This paper investigates the nature of these problems in the selected sectors and focuses on the following four dimensions of market functioning: regulation, integration, competition and innovation. In spite of the data limitations, regulation appears to be a cross cutting factor affecting market functioning in many sectors. The service sectors, in particular, show signs of an unexploited potential in terms of market integration and competition pressures. In all selected sectors there are indications of an unsatisfactory innovation performance. Overall, the analysis appears to confirm the results of the initial sector screening.European economy, economic integration, regulation, competition, innovation, Internal Market, Single Market, structural policy, manufacturing sectors, service sectors, Ilzkovitz, Dierx, Sousa

Large Scale Railway Renewal Planning with a Multiobjective Modeling Approach

A multiobjective modeling approach for managing large scale railway infrastructure asset renewal is presented. An optimized intervention project schedule is obtained considering operational constraints in a three objectives model: evenly spreading investment throughout multiple years, minimizing total cost, minimizing work start postponements on higher priority railway sections. The MILP model was based on a real world case study; the objectives and constraints specified by an infrastructure management company. Results show that investment spreading greatly influences the other objectives and that total cost fluctuations depend on the overall condition of the railway infrastructure. The model can produce exact efficient solutions in reasonable time, even for very large-sized instances (a test network of similar size to the USA railway network, the largest in the world). The modeling approach is therefore a very useful, practical methodology, for generating optimized solutions and analyzing trade-offs among objectives, easing the task of ultimately selecting a solution and produce the works schedule for field implementation

Worker Sorting, Compensating Differentials and Health Insurance: Evidence from Displaced Workers

This article introduces an empirical strategy to the compensating differentials literature that i) allows both individual observed and unobserved characteristics to be rewarded differently in firms based on health insurance provision, and ii) selection to jobs that provide benefits to operate on both sides of the labor market. Estimates of this model are used to directly test empirical assumptions that are made with popular econometric strategies in the health economics literature. Our estimates reject the assumptions underlying numerous cross sectional and longitudinal estimators. We find that the provision of health insurance has influenced wage inequality. Finally, our results suggest there have been substantial changes in how displaced workers sort to firms that offer health insurance benefits over the past two decades. We discuss the implications of our findings for the compensating differentials literature.

Worker Sorting, Health Insurance and Wages: Further Evidence from Displaced Workers in the United States

The United States has the distinction of being the only industrialized nation without universal health insurance. Health insurance may have impacts on the US labor market. We use data on displaced workers over a 25 year period to document how the role of health insurance on wages and worker sorting has evolved. We find that the provision of health insurance increasingly influences wage inequality. Our results indicate that the portion of the unadjusted wage gap due only to selection bias from unobserved (to the analyst) characteristics, such as ability or innate health status has grown rapidly since 2000. Further, while there have been substantial changes in how displaced workers sort to firms that offer health insurance benefits over the last 25 years, many of the patterns have reversed directions over the past six years. Finally, we discuss the policy implications of our results.Health insurance; Worker sorting; Displacement; Comparative advantage; Non-linear instrumental variables

Bi-objective modeling approach for repairing multiple feature infrastructure systems

A bi-objective decision aid model for planning long-term maintenance of infrastructure systems is presented, oriented to interventions on their constituent elements, with two upgrade levels possible for each element (partial/full repairs). The model aims at maximizing benefits and minimizing costs, and its novelty is taking into consideration, and combining, the system/element structure, volume discounts, and socioeconomic factors. The model is tested with field data from 229 sidewalks (systems) and compared to two simpler repair policies, of allowing only partial or full repairs. Results show that the efficiency gains are greater in the lower mid-range budget region. The proposed modeling approach is an innovative tool to optimize cost/benefits for the various repair options and analyze the respective trade-offs.info:eu-repo/semantics/publishedVersio

Large scale railway renewal planning with a multiobjective modeling approach

Conferência realizada na Filândia, Helsinquia, de 20-24 de agosto de 2018A multiobjective modeling approach for managing large scale railway infrastructure asset renewal is presented. An optimized intervention project schedule is obtained considering operational constraints in a three objectives model: evenly spreading investment throughout multiple years, minimizing total cost, minimizing work start postponements on higher priority railway sections. The MILP model was based on a real world case study; the objectives and constraints specified by an infrastructure management company. Results show that investment spreading greatly influences the other objectives and that total cost fluctuations depend on the overall condition of the railway infrastructure. The model can produce exact efficient solutions in reasonable time, even for very large-sized instances (a test network of similar size to the USA railway network, the largest in the world). The modeling approach is therefore a very useful, practical methodology, for generating optimized solutions and analyzing trade-offs among objectives, easing the task of ultimately selecting a solution and produce the works schedule for field implementation.info:eu-repo/semantics/publishedVersio