Abstract
Ordinal classification is a specific and demanding task, where the aim is not only to increase accuracy, but to also capture the natural order between the classes, and penalize incorrect predictions by how much they deviate from this ranking. If an ordinal classifier must be able to comply with all these requirements, a suitable ordinal metric must be able to accurately measure its degree of compliance. However, the current metrics are unable to completely capture these considerations when assessing classification performance. Moreover, most suffer from sensitivity to imbalanced classes, very common in ordinal classification. In this paper, we propose two variants of a novel performance index that accounts for both accuracy and ranking in the performance assessment of ordinal classification, and is robust against imbalanced classes. © 2018 IEEE.

Abstract
Alloy supports reasoning about software designs in early development stages. It is composed of a modelling language and a tool that is able to find valid instances of the model. Alloy is able to produce graphical representations of analysis results, which is essential for their interpretation. In previous work we have improved the representations with the usage of layout managers. Here, we further extend that work by presenting the improvements on the approach, and by introducing a new case study to analyse the contribution of layout managers, and to support validation trough a user study.

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Resumo Este estudo visa a identificar como mecanismos de controle externo e interno da governança corporativa, tipicamente considerados no setor empresarial privado, são aplicados ou transformados para o setor público nas empresas estatais. A partir de uma revisão do problema de agência e dos mecanismos propostos para sua mitigação no contexto empresarial, este estudo analisa a situação da governança das empresas estatais no Brasil e em Portugal, com vistas a comparar as soluções adotadas nos dois países e as necessidades de desenvolvimento. Além de compartilhar histórias e fundamentos culturais comuns, esses países são caracterizados como ambientes de pouca segurança aos investidores e fragilidade de instrumentos de solução de litígios, por estruturas de propriedade concentradas e por mercados de capitais ainda insuficientes para pressionar o comportamento das empresas, condições que fragilizam os mecanismos de mercado de controle externo e amplificam a influência das peculiaridades das questões internas de governança das estatais. As análises apontam significativas evoluções recentes nas práticas de governança das estatais, mas identificam desafios que ainda precisam ser direcionados.

Abstract
The energy sector is evolving rapidly, namely due to the increasing importance of renewable energy sources. The connection of large amounts of wind power generation poses new challenges for the dynamic voltage stability analysis of an electric power system, which has to be studied. In this paper, the traditional Doubly-Fed Induction Generator model is employed. Based on this model, a crowbar and chopper circuit is set up to protect the turbine during the short-circuit period. The EUROSTAG software package was used for the simulation studies of the system, and numerical results were obtained. Conclusions are drawn that provide a better understanding of the influence of crowbar and chopper protection on Doubly-Fed Induction Generators (DFIG), during low voltage ride through, in a system with wind power generation.