Browsing by Issue Date, starting with "2008-07"
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- Strongly-typed genetic programming and purity analysis: input domain reduction for evolutionary testing problemsPublication . Ribeiro, José Carlos Bregieiro; Zenha-Rela, Mário Alberto; Fernandéz de Vega, FranciscoSearch-based test case generation for object-oriented software is hindered by the size of the search space, which encompasses the arguments to the implicit and explicit parameters of the test object's public methods. The performance of this type of search problems can be enhanced by the definition of adequate Input Domain Reduction strategies. The focus of our on-going work is on employing evolutionary algorithms for generating test data for the structural unit-testing of Java programs. Test cases are represented and evolved using the Strongly-Typed Genetic Programming paradigm; Purity Analysis is particularly useful in this situation because it provides a means to automatically identify and remove Function Set entries that do not contribute to the definition of interesting test scenarios.
- Firm characteristics and country institutional development: business relationships with foreign firms in transition economiesPublication . Ferreira, Manuel Portugal; Li, Dan; Serra, Fernando RibeiroThe composition of firms' foreign business networks has been attended to in recent research but has seldom been subjected to empirical study in transition economies. In this study, we test hypotheses related to the composition of firms' foreign business relationships. First, we suggest that firms' characteristics matter for building a network of ties the foreign agents. Then, we consider the moderating effect of the degree of institutional development of the home country to assess to extent to which firms' foreign business relationships in transition economies are affected by the institutional development. We conduct a set of logistic regressions and one OLS regression to investigate the composition of firms' business relationships using firm-level data from 24 transition economies. The results indicate that firm size and membership in trade associations are good predictors of foreign business relationships – specifically, relationships with foreign investors, customers, and suppliers - and also of the diversity of foreign relationships. The country's institutional development radically changes which firms' characteristics matter in forming business relationships.
- Search-based test case generation for object-oriented Java software using strongly-typed genetic programmingPublication . Ribeiro, José Carlos BregieiroIn evolutionary testing, meta-heuristic search techniques are used to generate high-quality test data. The focus of our on-going work is on employing evolutionary algorithms for the structural unit-testing of object-oriented Java programs. Test cases are evolved using the Strongly-Typed Genetic Programming technique. Test data quality evaluation includes instrumenting the test object, executing it with the generated test cases, and tracing the structures traversed in order to derive coverage metrics. The strategy for efficiently guiding the search process towards achieving full structural coverage involves favouring test cases that exercise problematic structures and control-flow paths. Static analysis and instrumentation is performed solely with basis on the information extracted from the test objects' Java Bytecode. Relevant contributions include the introduction of novel methodologies for automation, search guidance and input domain reduction, and the presentation of the eCrash automated test case generation tool.
- A source code based model to generate GUI: GUI generation based on source code with declarative language extensionsPublication . Monteiro, Marco; Oliveira, Paula; Gonçalves, RamiroDue to data-driven application nature and its increasing complexity, developing its user interface can be a repetitive and time-consuming activity. Consequently, developers tend to focus more on the user interface aspects and less on business related code. In this paper, we present an alternative approach to graphical user interface development for data-driven applications, where the key concept is the generation of concrete graphical user interface from a source code based model. The model includes the original source code metadata and non-intrusive declarative language extensions that describes the user interface structure. Some Object Relational Mapping tools already use a similar concept to handle interoperability between the data layer and the business layer. Our approach applies the same concept to handle business and presentation layer interoperability. Also, concrete user interface implementation will be delegated to specialized software packages, developed by external entities, that provide complete graphical user interfaces services to the application. When applying our approach, we expect faster graphical user interface development, allowing developers to refocus on the source code and concentrate their efforts on application core logic.
- The impact of strategic resource seeking and market seeking strategies on foreign entry modes under institutional pressuresPublication . Ferreira, Manuel Portugal; Serra, Fernando RibeiroMultinational corporations (MNCs) are subject to the various dimensions of the external institutional environments where they operate. Institutional theory suggests that MNCs need to conform to the prevailing rules, norms and procedures of the locations where they operate in order to survive and grow. This means that MNCs need to develop the best possible configuration of strategy-structure for their worldwide operations. Previous research has noted that in these conditions firms may simply seek to follow a referent other. However, MNCs’ specific strategy for a focal foreign operation is likely to determine the entry mode for each host country. That is, in certain circumstances it may be whether MNCs are pursuing a market-seeking strategy or a strategic resource seeking strategy that shapes the entry mode in face of the prevailing institutional pressures. We contribute to the understanding of entry modes into foreign markets as a reflection of a strategic choice that is bound by institutional constraints.
- Composition of small and large firms' business networks in transition economiesPublication . Ferreira, Manuel Portugal; Li, Dan; Serra, Fernando RibeiroRecent research has theorized on the composition of firms' business networks but has not empirically examined business networks in transition economies may vary for different firms. In this study, using firm level data from twenty six transition economies collected by the World Bank and the EBRD in 1999-2000, we conduct a set of logistic regression models to investigate the composition of small and large firms' business networks. The results show that, in contrast to smaller firms, larger firms are more likely to have formal business relationships, and relationships with national and foreign financial institutions, government, and foreign firms. In addition, in a subgroup analysis of seven transition economies we show that the composition of the firms' business networks varies substantially across countries but that the government is still a dominant client. Furthermore, we found a large variation on firms' reliance on informal ties and the extent to which firms exchange with foreign firms.
- A multi-criteria decision approach to sorting actions for promoting energy efficiencyPublication . Neves, Luís Miguel Pires; Martins, António Gomes; Antunes, Carlos Alberto Henggeler; Dias, Luís Miguel CândidoThis paper proposes a multi-criteria decision approach for sorting energy efficiency initiatives, promoted by electric utilities, with or without public funds authorized by a regulator, or promoted by an independent energy agency, overcoming the limitations and drawbacks of Cost-Benefit Analysis. The proposed approach is based on the ELECTRE-TRI multi-criteria method and allows the consideration of different kinds of impacts, although avoiding difficult measurements and unit conversions. The decision is based on all the significant effects of the initiative, both positive and negative ones, including ancillary effects often forgotten in cost-benefit analysis. The ELECTRE-TRI, as most multi-criteria methods, provides to the Decision Maker the ability of controlling the relevance each impact can have on the final decision in a transparent way. The decision support process encompasses a robustness analysis, which, together with a good documentation of the parameters supplied into the model, should support sound decisions. The models were tested with a set of real-world initiatives and compared with possible decisions based on Cost-Benefit analysis.
- H.264/SVC ROI encoding with spatial scalabilityPublication . Ferreira, Lino; Cruz, Luís; Assunção, Pedro A. AmadoThis paper proposes two H.264/AVC compliant methods for encoding Regions-of-Interest (ROI) with spatial scalability and evaluates their respective rate-distortion-complexity performance. The base layer is kept unchanged and provides lower resolution images with roughly constant quality, without identification of the ROI. In the proposed methods there is no need to encode contour information because the ROI is implicitly defined in the upper layer of the spatial resolution in a transparent way by using different encoding parameters for the ROI and its complementary region. It is shown, that spatial scalability in ROI can be efficiently used to enhance specific regions of an image sequence in both spatial resolution and quality with low coding complexity. The proposed encoding scheme is suitable for remote surveillance, medical applications and entertainment, where higher resolution and higher quality ROI is a useful functionality for object/face recognition, selective encryption, detail analysis, etc.
- Aumento da IL-6 sérica pós-queimadura e falência multiorgânicaPublication . Cardoso, Susana; Cabral, Luis; Cruzeiro, Celso; Garção, Fátima; Rosa, Manuel SantosIntrodução: Quando comprometida a primeira linha de defesa, como acontece no contexto de queimadura, o sistema imunitário encontra-se numa situação muito particular. É induzida uma cascata pró-inflamatória acentuada. Têm sido registadas alterações ao nível do funcionamento dos macrófagos [1] e alterações das citocinas Th1/Th2 mas é difícil estabelecer situações-padrão e indicadores de prognóstico [2,3]. Fenómenos de sepsis e falência multiorgânica são habitualmente as causas de morte que advêm do descontrolo imunitário [4]. Material e Métodos: Para o presente estudo prospectivo, foram seleccionados 20 doentes, de idades compreendidas entre os 25 e 50 anos, com queimaduras de segundo e terceiro graus e uma área queimada (TBSA) de 20% a 60%. Todos os indivíduos foram sujeitos a balneoterapia e enxertos. Nenhum dos doentes apresentava anomalias ou problemas crónicos antes do acidente. Quantificaram-se as interleucinas IL-6, IL-8, IL-10 e IL-12, células NK e subpopulações linfocitárias. A monitorização iniciou-se o mais precoce possível após a admissão hospitalar, repetindo-se três dias depois e com intervalos de uma semana. Resultados: Verifica-se uma desregulação da imunidade celular e alterações das citocinas. Entre os não-sobreviventes foram registados valores mais reduzidos de células NK e células T helper e um ratio CD4/CD8 mais elevado. Ainda nestes doentes, o acentuado aumento da IL-6 especialmente aquando da admissão (p<0,02), parece causar uma inflamação persistente e excessiva que pode conduzir à falência multiorgânica, por impedimento da reconstrução tecidular. Conclusões: Os processos responsáveis pelo fracasso da resposta imunitária na queimadura, são uma ampla reacção inflamatória mediada pela produção excessiva de IL-6, parcialmente relacionada com a área queimada e uma depressão da imunidade celular. Este parâmetro (IL-6) pode ser um forte indicador de prognóstico e vir a ser um alvo terapêutico de imunomodulação. Por análise de toda a variação registada ao nível das interleucinas analisadas, não existe evidência de comprometimento Th1.