Essays on corporate governance

Doutoramento em Gestão. Especialização em Finanças.Na presente dissertação são apresentados quatro ensaios sobre governo das sociedades. No primeiro ensaio é analisada a remuneração dos CEO das empresas cotadas portuguesas. Os resultados obtidos revelam que os fatores específicos das empresas explicam grande parte da variabilidade da remuneração total dos CEO, ao passo que o desempenho das empresas explica menos de 5%. Outras características do governo destas sociedades estão também relacionadas com a remuneração dos CEO. No segundo ensaio é analisada a relação entre o desempenho da empresa e o governo das sociedades, com especial enfoque nas características dos CEO, designadamente quanto ao nível e tipo de educação. Além da relação entre o governo das sociedades cotadas portuguesas e o seu desempenho, os resultados sugerem ainda que existe uma relação positiva entre o nível de educação dos CEO e o desempenho das empresas. No terceiro ensaio é analisado efeito da diversidade de género no conselho de administração na redução dos custos de agência. Os resultados empíricos suportam esta relação. Adicionalmente é encontrada evidência de que as empresas mais complexas e com maior preocupação acerca da independência dos seus dirigentes têm maior diversidade de género no conselho de administração. Por fim, no último ensaio é analisado o efeito da composição do conselho de administração na política de financiamento. Os resultados obtidos suportam a ideia de que conselhos de administração mais independentes reduzem a assimetria de informação, levando a uma maior utilização de fontes externas de capital tais como ações e dívida de longo prazo.This dissertation presents four empirical essays on corporate governance. The first essay analyses Portuguese CEO’s earnings. It is found that firm specific factors accounts for the majority of the variance in total CEO pay, while firm performance accounts for less than 5%. It is also found that the CEO characteristics, board of directors’ structures, and shareholders features are related with the CEO pay. In the second essay, we analyse the relationship between company performance and governance characteristics allowing for CEO specific characteristics, such as education, age and tenure. The findings support the conclusion that firm performance relates positively to the CEO’s level of educational attainment. Other governance-specific characteristics also explain this relationship, namely, the presence of independent directors on the board and voting cap restrictions. The third essay empirically analyses whether gender diversity enhances boards of directors’ independence and efficiency. The empirical results support this hypothesis. Moreover, this essay finds that firms that are concerned with board independence and those in more complex environments are more likely to have gender-balanced boards. Finally, the fourth essay empirically analyses the association between the board of directors’ composition and a firm’s financing policies. It is theorised that a more independent and efficient board leads to a shift of financing choices from retained earnings to short-term debt, from short-term debt to long-term debt, and from long-term debt to external equity financing. The results obtained in this last study support this hypothesis.N/

Alpargatas S.A. : equity valuation

Alpargatas S.A. is the largest footwear manufacturing company in Latin America and aspires to become a global company of desired brands in the footwear, apparel and accessory industries, under the brand names Havaianas, Osklen, Topper, Rainha, Dupe, Mizuno, and Timberland (the firm owns the license of the two last brands to operate in Brazil). The present dissertation was developed by Rogério Paulo Oliveira de Morais and aims to value an equity investment on Alpargatas S.A. (ALPA4 BZ). The valuation model implemented to compute the fair value of ALPA4 results from an extensive literature review on the subject, as well as an extensive analysis of the company and the industry. As a result, the model is based on a two scenarios DCF supported by a Relative Valuation. The target price estimated is of R$ 8.98 per share, which implies a upside potential of 23.8% and results on a “BUY” recommendation. In the end, the results will be compared to the ones obtained by the Itaú BBA Equity Research team in the 27/11/2014 report

Evaluation of performance of European cities with the aim of increasing quality of life

Tese de Doutoramento. Engenharia Industrial e Gestão. Faculdade de Engenharia. Universidade do Porto. 201

A data mining approach to predict forest fires using meteorological data

Forest fires are a major environmental issue, creating economical and ecological damage while endangering human lives. Fast detection is a key element for controlling such phenomenon. To achieve this, one alternative is to use automatic tools based on local sensors, such as provided by meteorological stations. In effect, meteorological conditions (e.g. temperature, wind) are known to influence forest fires and several fire indexes, such as the forest Fire Weather Index (FWI), use such data. In this work, we explore a DataMining (DM) approach to predict the burned area of forest fires. Five different DM techniques, e.g. Support Vector Machines (SVM) and Random Forests, and four distinct feature selection setups (using spatial, temporal, FWI components and weather attributes), were tested on recent real-world data collected from the northeast region of Portugal. The best configuration uses a SVM and four meteorological inputs (i.e. temperature, relative humidity, rain and wind) and it is capable of predicting the burned area of small fires, which are more frequent. Such knowledge is particularly useful for improving firefighting resource management (e.g. prioritizing targets for air tankers and ground crews)

COVID-19 time series forecasting – twenty days ahead

Occupational exposure to cytotoxic agents has been recognized as a potential danger to the health of handlers. However, collective and individual protection equipment has been developed for use by professionals. This article aims to identify and describe the protection equipment applicable to a centralized unit of cytostatics preparation, using a qualitative and quantitative descriptive analysis. A questionnaire survey yielded 83 responses, covering 18 centralized cytostatic preparation units. The results show some weaknesses detected in some institutions such as the absence of a shower and eyewash fountain, the lack of knowledge about the procedures manual, and the use of a surgical mask. However, the results point to awareness by the general manipulators regarding the use of some personal protective equipment. This study contributes to the investigation of the use of equipment for the protection of cytostatic manipulators at work in centralized cytostatic preparation units.This work was supported by Fundação para a Ciência e Tecnologia within the Project Scope: UIDB/05757/2020.info:eu-repo/semantics/publishedVersio

Analysis and forecasting incidence, intensive care unit admissions, and projected mortality attributable to COVID-19 in Portugal, the UK, Germany, Italy, and France: predictions for 4 weeks ahead

The use of artificial neural networks (ANNs) is a great contribution to medical studies since the application of forecasting concepts allows for the analysis of future diseases propagation. In this context, this paper presents a study of the new coronavirus SARS-COV-2 with a focus on verifying the virus propagation associated with mitigation procedures and massive vaccination campaigns. There were two proposed methodologies in making predictions 28 days ahead for the number of new cases, deaths, and ICU patients of five European countries: Portugal, France, Italy, the United Kingdom, and Germany. A case study of the results of massive immunization in Israel was also considered. The data input of cases, deaths, and daily ICU patients was normalized to reduce discrepant numbers due to the countries’ size and the cumulative vaccination values by the percentage of population immunized (with at least one dose of the vaccine). As a comparative criterion, the calculation of the mean absolute error (MAE) of all predictions presents the best methodology, targeting other possibilities of use for the method proposed. The best architecture achieved a general MAE for the 1-to-28-day ahead forecast, which is lower than 30 cases, 0.6 deaths, and 2.5 ICU patients per million people.This work has been supported by Fundação para a Ciência e Tecnologia within the Project Scope: UIDB/05757/2020.info:eu-repo/semantics/publishedVersio

Anomalous shift of the recombination energy in single asymmetric quantum wells

Self-consistent numerical calculation and photoluminescence (PL) measurements have been used to investigate the temperature dependence of the optical Stark effect in n-doped GaAs/AlGaAs single asymmetric quantum wells (SAQWs), grown by molecular beam epitaxy. In the low-temperature regime (5 to 40 K) a remarkable blue shift (9.8 meV) is observed in the PL peak energy, as the optical excitation intensity increases from 0.03 to 90 W/cm2. The blue shift is well explained by the reduction of the two-dimensional electron gas (2DEG) density, due to a charge-transfer mechanism. At about 80 K, however, an anomalous behavior of the PL peak energy was found, i.e. a red shift has been observed as the optical excitation intensity increases. This anomalous behavior has been explained by combining the effects of band gap renormalization, band bending, temperature dependence of the band gap, temperature dependence of the 2DEG density, and temperature dependence of the fundamental energy position

Tolerância a faltas bizantinas usando técnicas de introspecção de máquinas virtuais

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Ciência da Computação, Florianópolis, 2015.Atualmente é quase impossível uma pessoa não utilizar direta ou indiretamente um sistema computacional. Ao realizar uma operação bancária ou até mesmo ao fazer compras em uma loja, nós somos auxiliados por sistemas computacionais. Em contrapartida, surgem novos ataques para comprometer o funcionamento correto dos sistemas utilizados. Várias técnicas são utilizadas para que os sistemas funcionem conforme sua especificação, entre elas,destacam-se sistemas tolerantes a faltas bizantinas/intrusões (BFT) através de replicação de máquina de estados (RME). Nessa abordagem, é proposta uma arquitetura de sistema tolerante a intrusões que garante o seu funcionamento correto, mesmo na presença de réplicas faltosas.Este trabalho propõe um algoritmo que une replicação de máquina de estados e sistema de detecção de intrusões (IDS) para tolerar faltas bizantinas. A tecnologia de virtualização é utilizada no algoritmo proposto para replicar o serviço e também para isolar o IDS da aplicação monitorada. Dessa forma, é proposto um detector de intrusões como um componente confiável do sistema BFT. As principais contribuições são: (1) propor um modelo unificado, o qual utiliza replicação de máquina de estados e IDS em conjunto, e faz uso dos recursos da tecnologia de virtualização, (2) detector de intrusões como componente confiável do sistema e (3) elaborar um algoritmo BFT baseado no modelo proposto. Através desta abordagem foi possível reduzir o número de réplicas do sistema de 3f + 1 para 2f + 1 e reduzir o número de passos do protocolo do algoritmo tradicional BFT de Castro e Liskov de 5 para 3 no caso normal de operação e sem precisar da participação do cliente no protocolo.Abstract : Currently, it is almost impossible for a person not to use a computing system, in a direct or indirect way. When we are using a banking machine, or shopping in a store, we need to use a computing system. On the other hand, there are new attacks to damage the correct workingof the systems. There are several techniques to help the systems to work correctly according to their specification; among them, the Byzantine/intrusions fault tolerant systems (BFT) through the state machine replication (SMR) are important ones. In this perspective, it proposes a system architecture tolerant to intrusions that guarantees its proper functioning, even if there are faulty replicas.This research proposes an algorithm which presents a unified approachby using state machine replication and intrusion detection system in order to tolerate Byzantine faults. The virtualization technology is usedon the proposed algorithm to replicate the service and also to isolate the IDS of the monitored application. Therefore, we propose an intrusion detector as a reliable component of the BFT system. The main contributions are: (1) to propose a unified model, which uses state machine replication together with IDS, using the virtualization technology resources; (2) intrusion detector as a reliable component of the system; and (3) to make a BFT algorithm based on the proposed model. This approach made it possible to decrease the number of the system replicas from the 3f + 1 to 2f + 1, and to reduce the number of steps of the protocol of the BFT traditional algorithm from Castro and Liskov from 5 to 3 in a normal case of operation without the participation of the client in the protocol