Aldina Correia

• PhD
• Professor at Polytechnic Institute of Porto

In discussions on environmental policies, eco-efficiency is often underlined. Eco-efficiency is defined as delivering products and services with competitive value while simultaneously reducing the ecological impacts and meeting human needs. In highly competitive industrial environments, improvements in production processes are crucial for maintaini...

Female entrepreneurship is increasingly important to create new jobs and contribute to countries’ social and economic growth. This paper aims to examine how innovation and internationalisation interact from a female entrepreneurship perspective. Our research was based on the fuzzy-set qualitative comparative analysis (fsQCA) method as a means of ex...

Purpose This study aims to analyze the impact of technology and innovation on businesses’ internationalization process as well as the relationship between innovation and technology and internationalization. Design/methodology/approach The study was based on quantitative analysis of secondary data from 30 economies in Europe and Central Asia, extra...

In the discussion on environmental policies, the notion of eco-efficiency is often used. Eco-efficiency is defined as the delivery of products and services with competitive values, while reducing the ecological impacts and satisfying human needs. In an environment of great competitiveness in which the companies operate, the improvements in the prod...

This study sought to analyze the role female entrepreneurship plays in the internationalization and innovation process of firms. Additionally, this study aims to contribute to a better understanding of how the countries of Europe and Central Asia are grouped in terms of female entrepreneurship. Our analysis used secondary data collected from the En...

Structural conditions and population characteristics of countries have been identified in the literature as factors for an individual to become, or to have intentions of becoming, an entrepreneur. However, this is still a subject under research, which has become increasingly relevant and could be crucial in the current challenges of European countr...

Purpose Drawing on the resource-based view (RBV) and knowledge-based view (KBV) theories, this study contributes to deepen the knowledge that corporate social responsibility (CSR) exerts on firms' innovation, considering the role played by cooperation. The research also seeks to ascertain the factors that influence the development of business coope...

Purpose This study aims to distinguish businesses by their degree of complexity and to analyse the influence of complexity on the performance of firms during the coronavirus disease 2019 (COVID-19) pandemic. Design/methodology/approach Data were collected from 468 businesses, and various multivariate statistical techniques were used. Initially a f...

Entrepreneurship is a theme of global interest, and it is the subject of investigations conducted by many researchers and projects. In particular, the Global Entrepreneurship Monitor project is a global project that involves several countries and years of surveys on entrepreneurship indicators. This study focuses on the 12 indicators of the entrepr...

b-Mat@plicada is a b-learning Mathematics course for Higher Education students, mainly composed of educational videos available in the institutional Moodle platform. These contents were created by following a set of guidelines, where three components are considered: the quality of students’ learning, the teacher’s time and computer skills, as well...

Purpose Public policies provide a way for governments to influence the effectiveness of business strategies in the international marketplace. The main goal of this article is to show the importance of key aspects for policymaking at the national level and, secondly, to try to evaluate if public policies and programmes are effective in the entrepren...

Abstract This paper addresses a case study regarding inventory models for acquiring liquefied petroleum gas (LPG) cylinders. This is an industrial challenge that was proposed at an European Study Group with Industry, by a Portuguese energy company, for which the LPG cylinder is the main asset of its LPG business. Due to the importance of this asset...

The increasing complexity on knowledge exchanges leads firms to search beyond their own boundaries. Nowadays, companies are aware that can improve their internal capabilities resorting to external partners who detain complementary resources. Thus, at the firm level, cooperation has gained an important role in innovative processes, being considered...

In the liquefied petroleum gas (LPG) cylinder business, one of the most important assets is the LPG cylinder. This work addresses the asset acquisition planning for the LPG cylinder business of a company from the energy sector which has recently started this activity. In order to make the acquisition plan, it was necessary to forecast the sales and...

In this study, a logistic regression model is applied to credit scoring data from a given Portuguese financial institution to evaluate the default risk of consumer loans. It was found that the risk of default increases with the loan spread, loan term and age of the customer, but decreases if the customer owns more credit cards. Clients receiving th...

For assessing the structural features of organoclay C15A dispersions in PP/PP-g-MA melts under different processing conditions along the screws of Twin Screw Extruder, in this work four different clustering algorithms are considered. The best algorithm and number of clusters is selected using three internal validation measures: connectedness, Dunn’...

Mathematics is a basic and structural discipline of several Higher Education courses. Despite its comprehensive application to numerous real-world situations, students frequently demonstrate low levels of engagement and negative attitudes towards mathematics, which are also translated in poor achievement. In this context, teaching approaches might...

Globalization, radical and frequent changes as well as the increasing importance of applying knowledge through the efficient implementation of innovation is critical under the current circumstances. Innovation has been the source of businesses competitive advantage, but it is not restricted to technological innovations, and thus marketing innovatio...

Protecting the environment is at the moment essential for ensuring sustainability for future generations. Climate change and carbon dioxide (\(CO_2\)) emissions are primarily responsible for the process and delivery of the Global Warming. This paper aims to study how the various policies and economies in the world influence \(CO_2\) emissions. For...

The recognised importance of innovation and their role in competitiveness of firms is well-known. Marketing innovation is one aspect of the general innovation process and, as such, deserves to be explored. Based on a sample of 6,840 Portuguese firms which replied the 2012 Community Innovation Survey, multivariate techniques (factor analysis and mul...

This work aims to analyse entrepreneur's perceptions about conditions to create new and growing firms and their significance in the economic development level (EDL) of countries. For this paper was used Global Entrepreneurship Monitor (GEM) project, in particular, the dataset NES 2013. To group the variables related to entrepreneur's perceptions ab...

The recognised importance of innovation and their role in competitiveness of firms is well-known. Marketing innovation is one aspect of the general innovation process and, as such, deserves to be explored. Based on a sample of 6,840 Portuguese firms which replied the 2012 Community Innovation Survey, multivariate techniques (factor analysis and mul...

The growing globalization of the different types of market requires that companies invest, in a recurrent way, to optimize and improve all the processes inherent to their activities. Aluminium extrusion is the main industrial process used to create profiles of a fixed cross-section. This process requires appropriate processing parameters to be used...

The effect of organophilic clay (C15A) in PP compatibilized polymer (PP/PP-g-MA) through rheological experimental results is presented. This study focusses on the description of the rheological behaviour of the organophilic layers along the screws of a twin screw extruder by melting process, varying the screw profile as well as the processing condi...

This study focus on the twelve indicators of the entrepreneurial ecosystem, defined by the Global Entrepreneurship Monitor (GEM) project – the Entrepreneurial Framework Conditions (EFCs). EFCs are relate more specifically to the quality of the entrepreneurial ecosystem. The present study analyses how experts’ perceptions have changed in Portugal be...

Thermomechanical stress levels have a positive impact on dispersion of layered material by extrusion process. In order to contribute to the knowledge of this process, in previous work, PP nanocomposites were laboratory melted in a co-rotating twin-screw extruder by changing the processing conditions: screw profile and speed, temperature and output....

Purpose The main concern of policymakers is to avoid the problems resulting from the economic crisis. One way to avoid these problems is to stimulate economic growth, as well as the economic activity, needed to reduce unemployment and increase well-being. Recent academic literature shows entrepreneurship as a key factor to increase economic growth...

Developing general global optimization algorithms is a difficult task, specially for functions with a huge number of local minima in high dimensions. Stochastic metaheuristic algorithms can provide the only alternative for the solution of such problems since they are aimed at guaranteeing global optimality. However, the main drawback of these algor...

Entrepreneurship is defined as the effort to generate and create jobs and innovate leading to economic growth. Despite the importance that has been given to this phenomenon, inequalities regarding the ability to trigger and manage the entrepreneurial activity remain. This research aims to describe and account for the entrepreneurship levels, partic...

Corporate Social Responsibility (CSR) is a lasting ethical position toward the organization, the market and the society. For higher education institutions (HEI), CSR is a very timely topic, they must invest in their strategies and build a responsible approach into, not only their management activities, but also in their education programs. The purp...

In this paper we address a challenge proposed by a Portuguese energy sector company at an European Study Group with Industry. The company wanted to forecast the demand and return rate of Liquefied Petroleum Gas (LPG) cylinders. To address this challenge, sales data provided by the company as well as national data were analysed. The methodology prop...

High-growth businesses are a relevant phenomenon for economies as they represent an important driver for economic growth and an efficient allocation of resources that can be inductive of wealth creation. Despite the importance that has been given to this phenomenon, inequalities regarding the ability to trigger and manage the entrepreneurial activi...

In the aluminium industry, the chain of processes is long and involves different operations, starting with operations related to the extractive industry and ending with the piece of aluminium that would be sold. To make this process solid, viable and competitive, companies involved need to base their decisions on a consistent set of data, which ena...

The original global entrepreneurship monitor model predicts that the business activity at the national level varies with the general national framework conditions, while entrepreneurial activity varies with the entrepreneurial framework conditions (Reynolds et al., 2005). The aim of the national expert survey is to provide a general diagnostic appr...

In this paper we present a multinomial logistics regression to model the experts' perceptions about the Entrepreneurship Framework Conditions, using the most recently available data from GEM, i.e., NES 2013. The expert's type is described by a nominal variable with five categories, i.e.: "entrepreneur"; "investor, financer, banker"; "policy maker";...

Constrained nonlinear optimization problems can be solved using penalty or barrier functions. This strategy, based on solving unconstrained problems obtained form the original problem, has shown to be effective , particularly when used with direct search methods. An alternative to solve the above mentioned problems is the filters method. The filter...

Community Innovation Survey Innovation 2010 (CIS 2010) is used in this work to study the innovation level in Portuguese Firms. We use factorial analysis to identify the determinants and obstacles to innovation in Portuguese firms. The sources of innovation and cooperation to innovation are also analysed. After identifying the factors, the main sour...

In this article, a new approach to study the compatibilization effect of organophilic clays in PA6/PP polymer blends through experimental results of mechanical tests is presented. This study focus on the description of the interphase in compatibilization by addition of the organoclays C15A and C30B into the polymer PA6/PP blend by melt compounding...

The Global Entrepreneurship Monitor is a large scale database for internationally comparative entrepreneurship. This database includes information of more than 100 countries concerning several aspects of entrepreneurship activities, perceptions, conditions, national and regional policy, among others, in two main sources of primary data: the Adult P...

The damage caused by noise in workers’ health is well known. The European Agency for Safety and Health at Work presented in 2005 a summary of main effects of workplace noise, defining the loss of hearing as the principal effect of noise exposure, however, it can also exacerbate stress and increase the risk of accidents. The problem to be addressed...

This chapter seeks to analyse, based on a quantitative approach, the relationship between knowledge, cooperation and co-creation of innovation through knowledge-intensive business services (KIBS) and other organisations (i.e. clients, higher education institutions [HEIs] and other firms/institutions). The main findings suggest, given the context of...

At the 127 th European Study Group with Industry an energy sector company proposed an industrial challenge that consisted on the asset acquisition planning for its liquefied petroleum gas (LPG) cylinder business, one of the most recent business areas in the company. This business area is still in a growing phase and to satisfy the market needs and...

Abstract In the current environment, it is essential to recognize social responsibility as an im-portant corporate decision, which involve socially responsible actions by companies. As such, it is relevant to investigate the perceptions of future employees / employers /entrepreneurs, that is, students of today, in relation to this subject. Using a...

Purpose The success of the family firms cannot be detached from the current paradigm where, within the present economic conditions, economic agents struggle to exploit the existing opportunities and need to take into account the risks associated to the international arena and the innovation processes. The internationalisation and innovation process...

In this paper a dataset containing biological variables of the water column of several Portuguese reservoirs is analyzed. Hierarchical cluster analysis is used to obtain clusters of phytoplankton variables of the phylum Cyanophyta, with the objective of validating the classification of Portuguese reservoirs previewly presented in [1] which were div...

In this work we present a Factor Analysis of chemical and environmental variables of the water column and hydro-morphological features of several Portuguese reservoirs. The objective is to reduce the initial number of variables, keeping their common characteristics. Using the Factor Analysis, the environmental variables measured in the epilimnion a...

Innovation is a topic of interest for the management researchers, confirmed by the creation of a Community Innovation Survey, which is an harmonised tool designed to provide information about Innovation in European Union enterprises. In this study, we use factorial analysis to identify the determinants and obstacles to innovation in Portuguese firm...

Air pollution is a major environmental problem which can present a significant risk for human health. This paper, presents the evaluation of the air quality in several region of Portugal. Special focus is given to the region of Tâmega e Sousa where ESTG/P. Porto is located. ANOVA and MANOVA techniques are applied to study the differences between ai...

The effect of processing conditions of material and interfacial/ interphase properties in clay/polymer nanocomposites are usually studied through experimental results of X-ray diffraction, transmission electron microscopy and rheology mechanical tests. In this paper, the interaction of the experimental parameters and properties measure results are...

This paper, presents the evaluation of the air quality in several regions of Portugal, with special focus on the region of Tâmega e Sousa where ESTG/P.Porto is located. The ANOVA and MANOVA techniques are applied to study the differences between air quality from 2009 to 2012 in Portugal. The data used in this analysis includes altitude, area, expen...

Credit scoring is an application of financial risk forecasting to consumer lending. In this study, statistical analysis is applied to credit scoring data from a financial institution to evaluate the default risk of consumer loans. The default risk was found to be influenced by the spread, the age of the consumer, the number of credit cards owned by...

Global Entrepreneurship Monitor is a large scale database for internationally comparative entrepreneurship that includes information about many aspects of entrepreneurship activities, perceptions, conditions, national and regional policy, among others, of a large number of countries. This project has two main sources of primary data: the Adult Popu...

The maximum likelihood method is usually chosen to estimate the regression parameters of Generalized Linear Models (GLM) and also for hypothesis testing and goodness of fit tests. The classical method for estimating GLM parameters is the Fisher scores. In this work we propose to compute the estimates of the parameters with two alternative methods:...

Optimization methods have been used in many areas of knowledge, such as Engineering, Statistics, Chemistry, among others, to solve optimization problems. In many cases it is not possible to use derivative methods, due to the characteristics of the problem to be solved and/or its constraints, for example if the involved functions are non-smooth and/...

In this work, cluster analysis is applied to a real dataset of biological features of several Portuguese reservoirs. All the statistical analysis is done using R statistical software. Several metrics and methods were explored, as well as the combination of Euclidean metric and the hierarchical Ward method. Although it did not present the best combi...

Constrained nonlinear optimization problems are very common in real live situations and in several areas of knowledge. To handle the constrains in these problems Penalty and barrier techniques are widely used. In penalty or barrier methods a sequence of unconstrained problems is constructed and then they are solved using unconstrained optimization...

Finding the optimal value for a problem is usual in many areas of knowledge where in many cases it is needed to solve Nonlinear Optimization Problems. For some of those problems it is not possible to determine the expression for its objective function and/or its constraints, they are the result of experimental procedures, might be non-smooth, among...

Fingerprinting is a location technique, based on the use of wireless networks, where data stored during the offline phase is compared with data collected by the mobile node during the online phase. When this location technique is used in a real-life scenario there is a high probability that the mobile node used throughout the offline phase is diffe...

Fingerprinting is an indoor location technique, based on wireless networks, where data stored during the offline phase is compared with data collected by the mobile device during the online phase. In most of the real-life scenarios, the mobile node used throughout the offline phase is different from the mobile nodes that will be used during the onl...

This paper presents a novel approach to WLAN propagation models for use in indoor localization. The major goal of this work is to eliminate the need for in situ data collection to generate the Fingerprinting map, instead, it is generated by using analytical propagation models such as: COST Multi-Wall, COST 231 average wall and Motley-Keenan. As Loc...

Indoor location systems cannot rely on technologies such as GPS (Global Positioning System) to determine the position of a mobile terminal, because its signals are blocked by obstacles such as walls, ceilings, roofs, etc. In such environments the use of alternative techniques, such as the use of wireless networks, should be considered. The location...

Penalty and Barrier methods are normally used to solve Nonlinear Optimization Constrained Problems. The problems appear in areas such as engineering and are often characterized by the fact that involved functions (objective and constraints) are non-smooth and/or their derivatives are not know. This means that optimization methods based on derivativ...

Constrained and unconstrained Nonlinear Optimization Problems often appear in many engineering areas. In some of these cases it is not possible to use derivative based optimization methods because the objective function is not known or it is too complex or the objective function is non-smooth. In these cases derivative based methods cannot be used...

Derivative-free nonlinear optimization filter simplex The filter method is a technique for solving nonlinear programming problems. The filter algorithm has two phases in each iteration. The first one reduces a measure of infeasibility, while in the second the objective function value is reduced. In real optimization problems, usually the objective...

Search Optimization methods are needed to solve optimization problems where the objective function and/or constraints functions might be non differentiable, non convex or might not be possible to determine its analytical expressions either due to its complexity or its cost (monetary, computational, time,...). Many optimization problems in engineeri...

In Nonlinear Optimization Penalty and Barrier Methods are normally used to solve Constrained Problems. There are several Penalty/Barrier Methods and they are used in several areas from Engineering to Economy, through Biology, Chemistry, Physics among others. In these areas it often appears Optimization Problems in which the involved functions (obje...

Nonlinear Optimization Problems are usual in many engineering fields. Due to its characteristics the objective function of some problems might not be differentiable or its derivatives have complex expressions. There are even cases where an analytical expression of the objective function might not be possible to determine either due to its complexit...

Optimization problems arise in science, engineering, economy, etc. and we need to find the best solutions for each reality. The methods used to solve these problems depend on several factors, including the amount and type of accessible information, the available algorithms for solving them, and, obviously, the intrinsic characteristics of the probl...

In real optimization problems, usually the analytical expression of the objective function is not known, nor its derivatives, or they are complex. In these cases it becomes essential to use optimization methods where the calculation of the derivatives, or the verification of their existence, is not necessary: the Direct Search Methods or Derivative...

Exposição Viva@Matemática 2007

Apresentação do Projeto

In this work we present a classification of some of the existing Penalty Methods (denominated the Exact Penalty Methods) and describe some of its limitations and estimated. With these methods we can solve problems of optimization with continuous, discrete and mixing constrains, without requiring continuity, differentiability or convexity. The board...

Apresentação do Projeto Viva@Matemática: uma forma diferente de aprender Matemática

O Projecto Viva@Matemática nasceu em 2005 na Escola Superior de Estudos Industriais e de Gestão do Instituto Politécnico do Porto (ESEIG_IPP) e, desde então, a sua exposição anual tem estado patente em todos os ProfMat(s). Este ano perante as condicionantes logísticas não nos é possível partilhar convosco todas as experiências aliciantes desta nov...

Pretendemos aproveitar a oportunidade oferecida pelo ProfMat2007 para apresentar e divulgar o Projecto Viva@Matemática: uma forma diferente de aprender Matemática, já conhecido por alguns mas, certamente ainda desconhecido por muitos. Este projecto visa divulgar e promover o gosto pela Matemática recorrendo, para isso, a uma abordagem lúdica, dive...

Apresenta-se uma proposta de abordagem lúdica para a introdução do estudo das permutações. (ver anexo)