Component-based software engineering: a quantitative approach

Dissertação apresentada para a obtenção do Grau de Doutor em Informática pela Universidade Nova de Lisboa, Faculdade de Ciências e TecnologiaBackground: Often, claims in Component-Based Development (CBD) are only supported by qualitative expert opinion, rather than by quantitative data. This contrasts with the normal practice in other sciences, where a sound experimental validation of claims is standard practice. Experimental Software Engineering (ESE) aims to bridge this gap. Unfortunately, it is common to find experimental validation efforts that are hard to replicate and compare, to build up the body of knowledge in CBD. Objectives: In this dissertation our goals are (i) to contribute to evolution of ESE, in what concerns the replicability and comparability of experimental work, and (ii) to apply our proposals to CBD, thus contributing to its deeper and sounder understanding. Techniques: We propose a process model for ESE, aligned with current experimental best practices, and combine this model with a measurement technique called Ontology-Driven Measurement (ODM). ODM is aimed at improving the state of practice in metrics definition and collection, by making metrics definitions formal and executable,without sacrificing their usability. ODM uses standard technologies that can be well adapted to current integrated development environments. Results: Our contributions include the definition and preliminary validation of a process model for ESE and the proposal of ODM for supporting metrics definition and collection in the context of CBD. We use both the process model and ODM to perform a series experimental works in CBD, including the cross-validation of a component metrics set for JavaBeans, a case study on the influence of practitioners expertise in a sub-process of component development (component code inspections), and an observational study on reusability patterns of pluggable components (Eclipse plug-ins). These experimental works implied proposing, adapting, or selecting adequate ontologies, as well as the formal definition of metrics upon each of those ontologies. Limitations: Although our experimental work covers a variety of component models and, orthogonally, both process and product, the plethora of opportunities for using our quantitative approach to CBD is far from exhausted. Conclusions: The main contribution of this dissertation is the illustration, through practical examples, of how we can combine our experimental process model with ODM to support the experimental validation of claims in the context of CBD, in a repeatable and comparable way. In addition, the techniques proposed in this dissertation are generic and can be applied to other software development paradigms.Departamento de Informática of the Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa (FCT/UNL); Centro de Informática e Tecnologias da Informação of the FCT/UNL; Fundação para a Ciência e Tecnologia through the STACOS project(POSI/CHS/48875/2002); The Experimental Software Engineering Network (ESERNET);Association Internationale pour les Technologies Objets (AITO); Association forComputing Machinery (ACM

EDMS Use in Local E-Government: Extent of Use and Overall Performance Mediated by Routinization and Infusion

This study analyzes the effects of several post-adoption behaviors (extent of use, routinization and infusion) on overall performance in using an Electronic Document Management System (EDMS). Furthermore, we test whether the routinization and infusion variables mediate the influence of the extent of use on overall performance. This research collects data from a survey answered by 2,175 employees (EDMS users) of Portuguese municipalities. The Partial Least Squares technique is applied to test the model. The results showed that routinization is directly predicted by the extent of use, whereas infusion is directly affected by the extent of use and also by routinization. Consequently, such post-adoptive behaviors are interrelated not only in a sequential process, but also in parallel. In addition, overall performance is directly influenced by routinization and infusion. Finally, an indirect effects analysis shows that routinization and infusion mediate the relationship between extent of use and overall performance

Alguns factores e condicionantes do sucesso escolar académico: a aplicação de modelos de regressão

O insucesso escolar tem vindo a motivar o estudo em vários domínios das ciências sociais, através não só da reflexão sobre o fenómeno e politicas educativas, bem como através da construção de modelos conceptuais e explicativos do insucesso escolar. O insucesso escolar em ambiente académico pode assumir outros contornos de complexidade que são merecedores de estudo, o que evidencia a necessidade de vislumbrar quais os seus principais factores. O estudo, no qual esta tese se baseia, teve como objectivo a construção de um modelo sócio-psicológico explicativo do sucesso escolar, bem como descortinar os principais factores sociológicos e psicológicos do insucesso académico numa instituição de ensino superior – o Instituto Politécnico de Bragança (IPB). Para isso procedeu-se à construção de um questionário para aplicar a uma amostra de 200 alunos de dois estabelecimentos do ensino (ESSA - Escola Superior de Saúde; ESTIG – Escola Superior de Tecnologia e Gestão) do IPB. Após a recolha da amostra aplicaram-se os Modelos de Regressão Linear Múltipla e de Regressão Logística, por forma a obter os modelo sociológico, psicológico e sócio-psicológico, capazes de predizer o sucesso ou a probabilidade de um aluno ter sucesso académico. Os resultados demonstram que em média os alunos da ESSA e os alunos do sexo feminino têm mais sucesso académico, e que um bom relacionamento dos alunos com os professores, um bom índice de motivação para estudo e um bom rendimento no agregado familiar são factores chave para o sucesso académico dos alunos.School failure has motivated studies in numerous areas of social sciences, not only through reflection on the subject and of educational policies but also through the construction of conceptual models of explanation of academic failure. Academic failure in an academic environment can bring some complexity that is worth studying, in order to find the main causes. This study aims to construct a socio-psychological model to explain academic failure, as well as to specify the main sociological and psychological causes of academic failure in a university environment - the Instituto Politécnico of Bragança. To achieve this goal, a questionnaire was applied to a sample of 200 students in two different schools (ESSA -Escola Superior de Saúde; ESTIG – Escola Superior de Tecnologia e Gestão). Multiple linear regression and a logistic regression models were applied in order to find the main predictors of the academic success as well as the most important variables to predict the probability of a student having academic success. The results showed that, on average, the students from ESSA and the female students had more academic success, and that a good relationship between students and teachers, a high motivation to study and a higher family aggregate income are key factors for the academic success of the students

O impacto do status profissional na saúde do trabalhador : uma comparação entre Brasil e Portugal

Tese (doutorado)—Universidade de Brasília, Intituto de Ciências Sociais, Departamento de Sociologia, 2017.O debate sobre as desigualdades sociais em saúde tem-se alastrado por todo o mundo desde a década de 1970, mas este debate constitui uma tarefa inacabada na medida em que este tipo de desigualdade persiste em sociedades democráticas como a do Brasil e de Portugal, tornando necessário estudar as disparidades sociais em saúde e encontrar padrões de saúde entre grupos sociais que permitam a obtenção de informação que proporcione uma intervenção mais incisiva em políticas de saúde pública e que abra caminho para a consolidação de um modelo social de saúde e para a adoção de uma nova postura epistemológica contra o modelo biomédico. Tendo em conta este contexto, a presente tese incorpora quatro estudos que visam estudar a relação entre status profissional (operacionalizada através da tipologia socioprofissional de classe ACM) e a saúde (saúde percebida, restrições de saúde, fatores de risco para a saúde e saúde mental) no Brasil e em Portugal através de testes estatísticos (one-way ANOVA, Kruskal-Wallis e Qui-Quadrado) e através da análise de correspondências múltipla (projetando os indicadores de saúde e categorias socioprofissionais de classe no espaço social). Para o Brasil analisaram-se os dados das respostas à Pesquisa Mundial em Saúde da OMS (2003) e do suplemento de saúde da Pesquisa Nacional por Amostra de Domicílios do IBGE (2008). Para Portugal, analisaram-se também os dados das repostas da Pesquisa Mundial em Saúde e procedeu-se a aplicação de um questionário de estado de saúde a uma amostra de 229 trabalhadores de Portugal Continental. Para além dessa análise de dados examinaram-se indicadores institucionais de saúde, laborais, ambientais, sociais e económicos que diferenciam as realidades brasileira e portuguesa em termos de saúde. Todos os estudos demonstraram que os grupos de menor status profissional (assalariados agrícolas, operários e desempregados) são os que apresentam pior saúde percebida e piores indicadores de saúde a nível de restrições no quotidiano e saúde mental, indiciando a existência de acentuadas desigualdades sociais em saúde consoante status profissional. No caso brasileiro essas desigualdades sociais se manifestam com maior assimetria, sendo os trabalhadores agrícolas os mais visados em termos de fatores de risco para saúde e pior saúde percebida. No caso português, as atenções dispersam-se pelos operários, assalariados agrícolas, desempregados e empregados executantes, sendo que todos estes grupos apresentam piores indicadores de saúde em comparação com os restantes.The debate over social inequalities in health has been spreading around the world since the 1970s. However, this debate constitutes an unfinished task due to the fact that this kind of inequality persists in democratic societies such as Brazil and Portugal, making it necessary to study the social disparities in health and find health patterns between social groups. This will allow us to obtain information that provides a more incisive intervention in public health policies and will open the way to the consolidation of a social health model and the adoption of a new epistomological posture against the biomedic model. Bearing in mind this context, the present thesis incorporates four studies which aim to study the relation between occupational status (operationalized through the socio-professional typology of ACM class) and health (perceived health, health constraints, health risk factors and mental health) in Brazil and Portugal through statistical tests (one way ANOVA, Kruskal-Wallis e Chi-square) and through the multiple correspondence analysis (projecting health indicators and socio-professional class categories in social space). For the Brazillian study, the data we analyzed came from the answers to the WHO´s Health World Reseach (2003) and the health supplement of IBGE´s National Household Survey (2008). For the Portuguese study, there were two data sets. The first one data also came from the Health World Reseach. The second one came from a questionnaire gathering data on the health condition of 229 workers in continental Portugal. In addition to the referred data analysis, there was an analysis on health, labour, environmental, social and economical institutional indicators that set aside the brazillian and portuguese societies in health terms. All studies demonstrated that groups with lower occupational status (agricultural workers, technical workers and unemployed) are the ones presenting lower perceived health and lower health indicators in everyday restrictions and mental health, suggesting the existence of strong social inequalities in health depending on the occupational status. In the brazillian case, these social inequalities are manifested with larger asymmetry, as agricultural workers are the most targeted in terms of health risk factors and worst perceived health. In the portuguese case, the focus spreads through technical workers, agricultural workers, unemployed workers, being that all these groups present worst health indicators in comparison with the remaining groups. We conclude, then, that context has some influence in the health situation of workers, but the relation between ocupational status and health remains.Le débat sur les inégalités sociales dans le domaine de la santé est en train de s’étaler partout dans le monde depuis les années 1970, mais ce débat est une tâche inachevée dans la mesure que ce type d’inégalité subsiste dans les sociétés démocratiques comme celle du Brésil et du Portugal, étant important étudier les déséquilibres sociaux dans la santé et trouver les normes de santé entre groupes sociaux qui permettent l’acquisition d’information qui puisse fournir une intervention plus percutante des politiques de santé publique et qui ouvre des voies à la consolidation d’un modèle social de santé et à l’adoption d’une nouvelle attitude épistémologique contre le modèle biomédical. Compte tenu de ce cadre, cette thèse englobe quatre études dont le but est celui d’étudier la relation entre statut occupationnel (mise en œuvre à travers la typologie socioprofessionnelle de classe ACM) et la santé (santé perçue, restriction de santé, facteurs de risque pour la santé et santé mentale) au Brésil et au Portugal effectués par des tests statistiques (one-way ANOVA, Kruskal-Wallis et Chi-Square) et l’analyse de correspondance multiple (concevant les indicateurs de santé et catégories socioprofessionnelle de classe dans le secteur social). Pour le Brésil, on a analysé les données de réponse à la Recherche Mondiale de Santé de l’OMS (2003) et du supplément de santé de l’Enquête Nationale par échantillon de Domiciles de l’IBGE (2008). Pour le Portugal, on a analysé aussi les données de réponse à la Recherche Mondiale de Santé et on a fait une enquête sur l’état de santé à un échantillon de 229 salariés du continent. Au-delà de cette analyse de données, on a vérifié les indicateurs institutionnels de santé, du travail, environnementaux, sociaux et économiques qui distinguent les réalités brésilienne et portugaise en ce qui concerne la santé. Toutes les études ont montré que les groupes de statut occupationnel plus bas (salariés agricoles, ouvriers et chômeurs) ce sont ceux qui présentent une qualité de santé inférieure ressentie et de pires indicateurs de santé au niveau des restrictions quotidiennes et santé mentale, montrant l’existence d’inégalités sociales significatives de santé en fonction du statut professionnel. En ce qui concerne le Brésil, ces inégalités sociales s’expriment avec une l'asymétrie accrue, étant les travailleurs agricoles les plus visés comme facteurs de risque pour la santé e pire santé ressentie. Au Portugal, les attentions se sont répandues entre les ouvriers, les salariés agricoles, chômeurs et employés exécutants, étant donné que ces groupes présentent les pires indicateurs de santé par rapport aux autres

The moderator role of Gender in the Unified Theory of Acceptance and Use of Technology (UTAUT): A study on users of Electronic Document Management Systems

Venkatesh et al. [1] tried to integrate predictability capabilities from the different existing models of technology acceptance. This produced the Unified Theory of Acceptance and Use of Technology (UTAUT). This comprehensive model resulted in the identification of common aspects. It proposed several constructs with a greater explanatory power and analyzed moderating drivers, such as age, Gender, experience and voluntariness of use. By doing so, UTAUT identifies three major drivers of behavioral intention: performance expectancy, effort expectancy and social influence. On the other hand, facilitating conditions and behavioral intention were identified as determinant factors of actual use [1]. In addition to previous considerations about UTAUT, empirical research has scarcely analyzed the moderating role of Gender [2]. This is why this paper particularly aims to fill this gap. Hofstede [3] describes strength, competitiveness and guidance for material success as social roles linked to male values, whilst modesty, tenderness, sensitivity and concern for the quality of life are values associated with women. With respect to UTAUT, existing studies have shown that performance expectancy positively influences behavioral intention more strongly for men (cf. [4], [5], [6] and [7]). Moreover, it has been observed that effort expectancy positively influences behavioral intention more strongly for women (cf. [4], [5] and [6]), while social influence positively affects behavioral intention more strongly for women (cf. [5], [7] and [8]). In our research, with the aim of testing the moderating effects of Gender, a sample of 2,175 users of Electronic Document Management Systems (EDMS) in Portuguese municipalities was used. Taking into account that Gender is a categorical variable, we have adopted a multi-group or multi-sample analysis [9] -dividing the sample into two groups (male = 748; female = 1,427) and estimating each group of observations separately. Before comparing the groups, an analysis of the measurement invariance was carried out to make sure that the construct measures were invariant between both groups [10]. Once the metric invariance had been assessed, we carried out a set of multi-group analyses –interpreting statistically-significant differences in path coefficients as moderating effects. On the one hand, the parametric approach considering both equal variances and different variances has been used [11, 12]. On the other hand, we have applied non-parametric approaches exemplified by the permutation test [13], and Henseler’s PLS multi-group analysis [10, 12, 14]. This study notes slight differences in the results of the aforementioned methods. As a result, the moderating effect of Gender on the relation between performance expectancy and behavioral intention showed that this relationship is stronger among men than women. Finally, a discussion on the implications of Gender as a moderator for the UTAUT model is included

Determinants of User Acceptance of a Local eGovernment Electronic Document Management System (EDMS)

On numerous occasions the significant value of the investments involved in the development of eGovernment and the expectations of governmental information systems use do not correspond to the rate of effective use. This scenario makes it difficult to justify the development of electronic government by governments and local authorities among its citizens. It is therefore important to understand the factors that influence the employees' intention of using governmental information systems. With the aim of understanding the determining factors of using an Electronic Document Management System (EDMS) in the context of Portuguese municipalities, this study develops an empirical analysis using the Unified Theory of Acceptance and Use of Technology (UTAUT) model, (Venkatesh et al., 2003). This model's application for information systems research in the governmental context has a weak expression and is unique in EDMS research. This empirical research follows a realist and positivist approach. Data was collected from a survey answered by 2,175 employees of Portuguese municipalities (EDMS users). Partial Least Squares (PLS) was used to test the model proposed. The results showed that Intention to Use is positively affected by Performance Expectancy, Effort Expectancy, Social Influence and Facilitating Conditions. With respect to the EDMS Use, the results showed that it is positively influenced by Intention to Use and Facilitating Conditions. The main result indicates that EDMS users believe that the use of this information system will help them to obtain performance benefits in their work. However, the increasing use of EDMS is not very influenced by the system's perceived ease of use. In short, this study provides a contribution to the Information Systems Acceptance and Adoption literature in local eGovernmental contexts. In addition, our contribution empirically tests the model for implementation in governmental organizations and provides a better understanding of the adoption and use of an EDM

Preyssler Heteropolyacids in the Self-Etherification of 5-Hydroxymethylfurfural to 5,5′-[Oxybis(methylene)]bis-2-furfural Under Mild Reaction Conditions

The synthesis of 5,5′-[oxybis(methylene)]bis-2-furfural (OBMF) from 5-hydroxymethylfurfural (5-HMF) was studied using bulk and alumina-supported Preyssler heteropolyacids (HPAs). The formation of OBMF was related to the amount of Brønsted acid sites, and the lowest yield of OBMF was obtained with supported HPAs. However, the Lewis acidity of the HPA supported on Al2O3 favored the formation of 2,5-dimethylfurane. The effects of solvent, catalyst loading, temperature, and reaction time on the selectivity to OBMF from 5-HMF were studied to optimize OBMF production using bulk Preyssler HPAs; a yield of 84 % to OBMF was obtained at 5 h and 343 K. These results demonstrate that bulk Preyssler HPA is a good candidate for OBMF synthesis under mild reaction conditions.Fil: Páez, Alexander. Universidad Pedagógica y Tecnológica de Colombia; ColombiaFil: Rojas, Hugo A.. Universidad Pedagógica y Tecnológica de Colombia;Fil: Portilla Zúñiga, Omar Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas ; ArgentinaFil: Sathicq, Angel Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas ; ArgentinaFil: Afonso, Carlos A. M.. Universidade de Lisboa; PortugalFil: Romanelli, Gustavo Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas ; ArgentinaFil: Martínez, José J.. Universidad Pedagógica y Tecnológica de Colombia; Colombi

Uma Apresentação da (Ga)Linha de Investigação: Tecnologia, Educação e Aprendizagem

p. 7-19Este documento pretende sistematizar de uma forma breve o trabalho que tem vindo a ser desenvolvido pela Linha de Investigação “Tecnologia, Educação e Aprendizagem” do CIPAF (Centro de Investigação Paula Frassinetti). O seu trabalho tem-se caracterizado por uma forte vertente de intervenção na mudança das práticas pedagógicas e utilização efectiva e criativa das TIC (tecnologias da informação e comunicação) no dia-a-dia da nossa escola e nos centros de estágio cooperantes

Identification of Key Functions Required for Production and Utilization of the Siderophore Piscibactin Encoded by the High-Pathogenicity Island irp-HPI in Vibrionaceae

This article belongs to the Collection Microbial Virulence Factors[Abstract] Piscibactin is a widespread siderophore system present in many different bacteria, especially within the Vibrionaceae family. Previous works showed that most functions required for biosynthesis and transport of this siderophore are encoded by the high-pathogenicity island irp-HPI. In the present work, using Vibrio anguillarum as a model, we could identify additional key functions encoded by irp-HPI that are necessary for piscibactin production and transport and that have remained unknown. Allelic exchange mutagenesis, combined with cross-feeding bioassays and LC-MS analysis, were used to demonstrate that Irp4 protein is an essential component for piscibactin synthesis since it is the thioesterase required for nascent piscibactin be released from the NRPS Irp1. We also show that Irp8 is a MFS-type protein essential for piscibactin secretion. In addition, after passage through the outer membrane transporter FrpA, the completion of ferri-piscibactin internalization through the inner membrane would be achieved by the ABC-type transporter FrpBC. The expression of this transporter is coordinated with the expression of FrpA and with the genes encoding biosynthetic functions. Since piscibactin is a major virulence factor of some pathogenic vibrios, the elements of biosynthesis and transport described here could be additional interesting targets for the design of novel antimicrobials against these bacterial pathogens.M.B. was supported by grant PID2019-103891RJ-100 from MCIN/AEI/10.13039/501100011033 (Spain). The work was also supported by grants RTI2018-093634-B-C21/C22 from MCIN/AEI/10.13039/501100011033/FEDER “A way to make Europe”. Work in University of Santiago de Compostela and University of A Coruña was also supported by grants GRC2018/018 and GRC2018/039, respectively, from Xunta de Galicia and BLUEBIOLAB (0474_BLUEBIOLAB_1_E), Programme INTERREG V A of Spain-Portugal (POCTEP). L.A. also thanks Xunta de Galicia for a predoctoral fellowship co-funded with the European Social Fund (ED481A-2019/081)Xunta de Galicia; GRC2018/018Xunta de Galicia; GRC2018/039Xunta de Galicia; ED481A-2019/08

Micromundos AIA: Ambientes Integrados de Aprendizagem (Análise de uma Investigação)

Micromundos AIA é um projecto de investigação que pretende construir, desenvolver, implementar e avaliar, dentro da comunidade educativa, “ambientes integrados de aprendizagem” em que a tecnologia é considerada uma mais valia importante no processo ensino/aprendizagem. Fundamenta-se, pois, numa metodologia de trabalho caracterizada pela investigação/acção, já que os resultados pretendidos são obtidos no/pelo decorrer do próprio processo em si mesmo. Este trabalho cooperativo (entre investigadores, professores colaboradores, estagiários e alunos de Jardim de Infância e Ensino Básico) concebeu-se para 3 micromundos distintos, embora assentes em metodologias e processos comuns: fundamentação teórica, guiões para os educadores, actividades com as crianças e página de apoio na Internet. O micromundo “Jardineiros do Mar” é dirigido a crianças de 4 e 5 anos e pretende construir um sítio da Internet que funcione como plataforma de aprendizagem colaborativa. O micromundo “Robot Roamer” joga com a aprendizagem de conceitos abstractos através de um objecto robótico concreto e tem como público-alvo crianças dos 6 aos 8 anos. O micromundo “Escrita Criativa” pretende construir uma plataforma facilitadora da aprendizagem da leitura e da escrita, onde crianças dos 8 aos 10 anos possam, de uma forma estimulante, re+criar histórias e outro tipo de relatos, através do jogo criativo entre o texto, a imagem, o som e os leitores/escritores, adultos e crianças