Persistence characteristics in financial prices: evidence from the portuguese stock market returns

The objective of this article is to provide additional knowledge to the discussion of long-term memory, leaning over the behavior of the main Portuguese stock index. The first four moments are calculated using time windows of increasing size and sliding time windows of fixed size equal to 50 days and suggest that daily returns are non-ergodic and non-stationary. Seeming that the series is best described by a fractional Brownian motion approach, we use the rescaled-range analysis (R/S) and the detrended fluctuation analysis (DFA). The findings indicate evidence of long term memory in the form of persistence. This evidence of fractal structure suggests that the market is subject to greater predictability and contradicts the efficient market hypothesis in its weak form. This raises issues regarding theoretical modeling of asset pricing. In addition, we carried out a more localized (in time) study to identify the evolution of the degree of long-term dependency over time using windows 200-days and 400-days. The results show a switching feature in the index, from persistent to anti-persistent, quite evident from 2010.

Bridging the gap between closed and open data. System proposal for the Portuguese Legislation

Esta dissertação apresenta uma proposta de sistema capaz de preencher a lacuna entre documentos legislativos em formato PDF e documentos legislativos em formato aberto. O objetivo principal é mapear o conhecimento presente nesses documentos de maneira a representar essa coleção como informação interligada. O sistema é composto por vários componentes responsáveis pela execução de três fases propostas: extração de dados, organização de conhecimento, acesso à informação. A primeira fase propõe uma abordagem à extração de estrutura, texto e entidades de documentos PDF de maneira a obter a informação desejada, de acordo com a parametrização do utilizador. Esta abordagem usa dois métodos de extração diferentes, de acordo com as duas fases de processamento de documentos – análise de documento e compreensão de documento. O critério utilizado para agrupar objetos de texto é a fonte usada nos objetos de texto de acordo com a sua definição no código de fonte (Content Stream) do PDF. A abordagem está dividida em três partes: análise de documento, compreensão de documento e conjunção. A primeira parte da abordagem trata da extração de segmentos de texto, adotando uma abordagem geométrica. O resultado é uma lista de linhas do texto do documento; a segunda parte trata de agrupar os objetos de texto de acordo com o critério estipulado, produzindo um documento XML com o resultado dessa extração; a terceira e última fase junta os resultados das duas fases anteriores e aplica regras estruturais e lógicas no sentido de obter o documento XML final. A segunda fase propõe uma ontologia no domínio legal capaz de organizar a informação extraída pelo processo de extração da primeira fase. Também é responsável pelo processo de indexação do texto dos documentos. A ontologia proposta apresenta três características: pequena, interoperável e partilhável. A primeira característica está relacionada com o facto da ontologia não estar focada na descrição pormenorizada dos conceitos presentes, propondo uma descrição mais abstrata das entidades presentes; a segunda característica é incorporada devido à necessidade de interoperabilidade com outras ontologias do domínio legal, mas também com as ontologias padrão que são utilizadas geralmente; a terceira característica é definida no sentido de permitir que o conhecimento traduzido, segundo a ontologia proposta, seja independente de vários fatores, tais como o país, a língua ou a jurisdição. A terceira fase corresponde a uma resposta à questão do acesso e reutilização do conhecimento por utilizadores externos ao sistema através do desenvolvimento dum Web Service. Este componente permite o acesso à informação através da disponibilização de um grupo de recursos disponíveis a atores externos que desejem aceder à informação. O Web Service desenvolvido utiliza a arquitetura REST. Uma aplicação móvel Android também foi desenvolvida de maneira a providenciar visualizações dos pedidos de informação. O resultado final é então o desenvolvimento de um sistema capaz de transformar coleções de documentos em formato PDF para coleções em formato aberto de maneira a permitir o acesso e reutilização por outros utilizadores. Este sistema responde diretamente às questões da comunidade de dados abertos e de Governos, que possuem muitas coleções deste tipo, para as quais não existe a capacidade de raciocinar sobre a informação contida, e transformá-la em dados que os cidadãos e os profissionais possam visualizar e utilizar.

The impact of national cultures on international marketing strategy and subsidiary performance of portuguese SME’s

The dynamic of the international business and its multidimensional nature requires the understanding of the complexities of different contexts dictated by cultural differences between countries. The purpose of this paper is to study, in depth howsmall and medium-sized companies develop their international marketing mix strategy in their overseas subsidiaries. We use the theoretical construct of Hofstede (1980, 1991) in the dimensions of Power Distance (PD), Uncertainty Avoidance (UA), Individualism (IND), Masculinity (MASC) and Long-Term Orientation (LTO) to assess the cross cultural differences between countries and the business practices to analyze the adaptation or standardization of the international marketing mix strategy of foreign Portuguese subsidiaries. Ourstudy uses an exploratoryand qualitative methodology. We conducted semi-structured interviews in order to achieve a good understanding ofinternational marketing mix strategy of four companies from different sectors. Our results show that the national cultural differences have great influence in the marketing strategy of the subsidiary. The business practices adjustments in the subsidiary company that proved to be necessary conditions for their performance are conducted by the products augmented offerings concerning the characteristics of the product, design and brand name in order to meet the requirements and specificities of the host country of the subsidiary.

A qualitative description of soil parameters variation due to a prescribed fire in Portuguese northwestern forests using Fuzzy Boolean Nets — The case study of Cabreira mountain

In this paper we study the modifications that occurred in some forest soil properties after a prescribed fire. The research focused on the alterations of soil pH, soil moisture and soil organic matter content during a two-year span, from 2008 to 2009. The study site is located in Anjos, Vieira do Minho municipality, a forest site that has suffered from recurrent wildfires for several decades. Furze (Ulex, sp.), broom (Cytisus, sp.), gorse (Chamaespartum tridentatum) and a very few disperse adult pine (Pinus sylvestris) are the predominant vegetation type in the study area. The average height of this shrub vegetation is around 1.5 m. The prescribed fire was conducted by the National Forestry Authority (AFN) in November 2008. Fuzzy Boolean Nets (FBN) were used to evaluate the alteration in soil parameters when compared with adjacent spots where: i) no fire occurrence was registered since 1998; ii) fire occurrence was registered in 2008; and iii) vegetation pruning by mechanical cut was done in Spring six months prior to the prescribed fire event. Results suggest that in the particular case of the studied site, Anjos, the observed soil properties alterations cannot be related with the prescribed fire.

Retaining repatriates: an exploratory study in portuguese companies

This study aims to understand the factors which may explain the retention of repatriates from companies acting within Portugal. These factors can be related either to the individual, or to the work, to the organisation or to non-working contexts. Eight companies located in Portugal have participated in this study. Several semi-structured interviews were done to 16 organizational representatives and to 28 repatriates. The obtained results show that the repatriates’ retention on the visited companies may be influenced by several categories of factors. We can conclude that it is (1) the good relation with the leadership, (2) the recognition of the performed job but, also (3) the seniority, (4) the age and the (5) depressed national job market. These are the major factors that emerge as relevant factors for the retention. Hence, there is not only one category of explaining determining factors for the retention decision, but there are several. These findings will be discussed in detail and implications and suggestions for future research will be proposed as well.

Motivations to participate in international trade fairs: the Portuguese experience

Motivations/barriers to participate in ITF

Participate (or not) in international trade fairs? Decision factors of Portuguese managers

Portugal is a small economy, with an open domestic market that needs competitive exporters to prosper. Trade fairs are an international promotion tool that can be used by firms when considering export development and expansion. This study identifies and evaluates the critical factors that influenced the decision making process of Portuguese SME’s (Small and Medium-Sized Enterprises) managers to participate (or not) in international trade fairs. The results indicate that the firm’s critical decisions factors to select an international trade fair were value for money and the stand (location, typology and size)

Radiation dose rates and exposure associated to Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) at locations of a Portuguese coal-fired power plant

Coal contains trace quantities of natural radionuclides such as Th-232, U-235, U-238, as well as their radioactive decay products and 40K. These radionuclides can be released as fly ash in atmospheric emissions from coal-fired power plants, dispersed into the environment and deposited on the surrounding top soils. Therefore, the natural radiation background level is enhanced and consequently increase the total dose for the nearby population. A radiation monitoring programme was used to assess the external dose contribution to the natural radiation background, potentially resulting from the dispersion of coal ash in past atmospheric emissions. Radiation measurements were carried out by gamma spectrometry in the vicinity of a Portuguese coal-fired power plant. The radiation monitoring was achieved both on and off site, being the boundary delimited by a 20 km circle centered in the stacks of the coal plant. The measured radionuclides concentrations for the uranium and thorium series ranged from 7.7 to 41.3 Bq/kg for Ra-226 and from 4.7 to 71.6 Bq/kg for Th-232, while K-40 concentrations ranged from 62.3 to 795.1 Bq/kg. The highest values were registered near the power plant and at distances between 6 and 20 km from the stacks, mainly in the prevailing wind direction. The absorbed dose rates were calculated for each sampling location: 13.97-84.00 ηGy/h, while measurements from previous studies carried out in 1993 registered values in the range of 16.6-77.6 ηGy/h. The highest values were registered at locations in the prevailing wind direction (NW-SE). This study has been primarily done to assess the radiation dose rates and exposure to the nearby population in the surroundings of a coal-fired power plant. The results suggest an enhancement or at least an influence in the background radiation due to the coal plant past activities.

The determinants of trade credit: a study of portuguese industrial companies

Despite the relevance of trade credit as a source of business financing, the topic is far from being considered exhausted, especially because there is no general and integrated theory explaining the causes and consequences of trade credit.Our research aims to contribute towards the literature that studies the determinants for granting and receiving trade credit. In this sequence, the present study seeks to empirically test some theories about the reasons why companies grant and receive commercial credit. For this purpose we apply a fixed effect model to a panel of 11 040 Portuguese industrial companies, of which 360 are large companies and the majority 10 680 are Small and Medium Enterprises (SME) for the period between 2003 and 2009. We conclude that large companies (with greater access to credit market) serve as financial intermediaries to their clients with less access to finance. In addition, it was observed that the supplier companies use trade credit as a legal means of price discrimination. Finally, financially constrained enterprises, especially in times of financial crisis, use commercial credit as an alternative source of funding, endorsing the hypothesis of substitution between trade credit and bank credit.

Impact of Social Responsibility Programmes in Stakeholder Satisfaction: An Empirical Study of Portuguese Managers’ Perceptions

Investigação no âmbito do Projeto de Doutoramento(PhD), especialidade de Gestão Global, Estratégia e Desenvolvimento Empresarial (ISCTE-IUL - 2012, classificação de “Aprovado com Muito Bom”).

ISO 9001 and business performance: a quantitative study in portuguese organizations

The effects of ISO 9001 quality certification process inside an organization may be considered on a wide range. This article places this phenomenon under a theoretical perspective and aims to analyze the impact of ISO 9001 quality standard on business performance according to the financial information data. More specifically, the impact of ISO 9001on productivity, business value and increase on sales is viewed through an econometric model of analysis concerning a panel data of Portuguese companies from the agro-food and to the construction sector. This analysis has presented interesting different results and in brief revealed that it may not be deterministically ascertained a direct connection between ISO 9001 certification and the improvement on business performance. Many other variables are committed to its success.

Volunteering for a Lifetime? Volunteers’ Intention to Stay in Portuguese Hospitals

The current study aims to study Hospital volunteers’ intention to stay in an organization through understanding motivation, management factors, and satisfaction. A total of 304 Hospital volunteers, mainly women, completed a questionnaire measuring motivations, management factors, satisfaction, and intention to stay. In this study, structural equation modeling was used. Results demonstrate that there is a positive relationship between (a) motivation and satisfaction, (b) management factors and satisfaction, (c) satisfaction and intention to stay, and (d) motivation and management factors. These results present important outcomes that should be reflected in the way organizations operate. This research indicates aspects which are most valued by volunteers and allows NPOs to design and establish appropriate and assertive management policies.

Trace metals in size-fractionated particulate matter in a Portuguese hospital: exposure risks assessment and comparisons with other countries

Hospitals are considered as a special and important type of indoor public place where air quality has significant impacts on potential health outcomes. Information on indoor air quality of these environments, concerning exposures to particulate matter (PM) and related toxicity, is limited though. This work aims to evaluate risks associated with inhalation exposure to ten toxic metals and chlorine (As, Ni, Cr, Cd, Pb, Mn, Se, Ba, Al, Si, and Cl) in coarse (PM2.5–10) and fine (PM2.5) particles in a Portuguese hospital in comparison with studies representative of other countries. Samples were collected during 1 month in one urban hospital; elemental PM characterization was determined by proton-induced X-ray emission. Noncarcinogenic and carcinogenic risks were assessed according to the methodology provided by the United States Environmental Protection Agency (USEPA; Region III Risk-Based Concentration Table) for three different age categories of hospital personnel (adults, >20, and <65 years) and patients (considering nine different age groups, i.e., children of 1–3 years to seniors of >65 years). The estimated noncarcinogenic risks due to occupational inhalation exposure to PM2.5-bound metals ranged from 5.88×10−6 for Se (adults, 55–64 years) to 9.35×10−1 for As (adults, 20–24 years) with total noncarcinogenic risks (sum of all metals) above the safe level for all three age categories. As and Cl (the latter due to its high abundances) were the most important contributors (approximately 90 %) to noncarcinogenic risks. For PM2.5–10, noncarcinogenic risks of all metals were acceptable to all age groups. Concerning carcinogenic risks, for Ni and Pb, they were negligible (<1×10−6) in both PM fractions for all age groups of hospital personnel; potential risks were observed for As and Cr with values in PM2.5 exceeding (up to 62 and 5 times, respectively) USEPA guideline across all age groups; for PM2.5–10, increased excess risks of As and Cr were observed particularly for long-term exposures (adults, 55–64 years). Total carcinogenic risks highly (up to 67 times) exceeded the recommended level for all age groups, thus clearly showing that occupational exposure to metals in fine particles pose significant risks. If the extensive working hours of hospital medical staff were considered, the respective noncarcinogenic and carcinogenic risks were increased, the latter for PM2.5 exceeding the USEPA cumulative guideline of 10−4. For adult patients, the estimated noncarcinogenic and carcinogenic risks were approximately three times higher than for personnel, with particular concerns observed for children and adolescents.

Assessment of ultrafine particles in Portuguese preschools: levels and exposure doses

The aim of this work was to assess ultrafine particles (UFP) number concentrations in different microenvironments of Portuguese preschools and to estimate the respective exposure doses of UFP for 3–5-year-old children (in comparison with adults). UFP were sampled both indoors and outdoors in two urban (US1, US2) and one rural (RS1) preschool located in north of Portugal for 31 days. Total levels of indoor UFP were significantly higher at the urban preschools (mean of 1.82x104 and 1.32x104 particles/cm3 at US1 an US2, respectively) than at the rural one (1.15x104 particles/cm3). Canteens were the indoor microenvironment with the highest UFP (mean of 5.17x104, 3.28x104, and 4.09x104 particles/cm3 at US1, US2, and RS1), whereas the lowest concentrations were observed in classrooms (9.31x103, 11.3x103, and 7.14x103 particles/cm3 at US1, US2, and RS1). Mean indoor/outdoor ratios (I/O) of UFP at three preschools were lower than 1 (0.54–0.93), indicating that outdoor emissions significantly contributed to UFP indoors. Significant correlations were obtained between temperature, wind speed, relative humidity, solar radiation, and ambient UFP number concentrations. The estimated exposure doses were higher in children attending urban preschools; 3–5-year-old children were exposed to 4–6 times higher UFP doses than adults with similar daily schedules.

Six sigma methodologies: implementation and impacts on Portuguese small and medium companies (SMES)

Artigo elaborador no âmbito dos trabalhos decorrentes à dissertação de Mestrado do Aluno David Leite, no Mestrado em Gestão Integrada Qualidade, Ambiente e Segurança, ESTGF-IPP, Oreintados pelos Professores Luís Fonseca (ISEP-IPP) e Vanda Lima (ESTGF-IPP).