Improving bankruptcy prediction in micro-entities by using nonlinear effects and non-financial variables

The use of non-parametric methodologies, the introduction of non-financial variables, and the development of models geared towards the homogeneous characteristics of corporate sub-populations have recently experienced a surge of interest in the bankruptcy literature. However, no research on default prediction has yet focused on micro-entities (MEs), despite such firms’ importance in the global economy. This paper builds the first bankruptcy model especially designed for MEs by using a wide set of accounts from 1999 to 2008 and applying artificial neural networks (ANNs). Our findings show that ANNs outperform the traditional logistic regression (LR) models. In addition, we also report that, thanks to the introduction of non-financial predictors related to age, the delay in filing accounts, legal action by creditors to recover unpaid debts, and the ownership features of the company, the improvement with respect to the use of solely financial information is 3.6%, which is even higher than the improvement that involves the use of the best ANN (2.6%)

El poder temporal del papa, según Ramón Llull, y postura de éste relativa a las controversias de su tiempo

Abstract not availabl

El Beato Ramón Llull en sus relaciones con la Escuela Franciscana de los siglos XIII-XIV

Abstract not availabl

El Beato Ramón Llull en sus relaciones con la Escuela Franciscana de los siglos XIII-XIV

Abstract not availabl

La "Donatio Constantini" en los escritos y en la mente de Ramón Llull

Abstract not availabl

Hybrid model using logit and nonparametric methods for predicting micro-entity failure

Following the calls from literature on bankruptcy, a parsimonious hybrid bankruptcy model is developed in this paper by combining parametric and non-parametric approaches.To this end, the variables with the highest predictive power to detect bankruptcy are selected using logistic regression (LR). Subsequently, alternative non-parametric methods (Multilayer Perceptron, Rough Set, and Classification-Regression Trees) are applied, in turn, to firms classified as either “bankrupt” or “not bankrupt”. Our findings show that hybrid models, particularly those combining LR and Multilayer Perceptron, offer better accuracy performance and interpretability and converge faster than each method implemented in isolation. Moreover, the authors demonstrate that the introduction of non-financial and macroeconomic variables complement financial ratios for bankruptcy prediction

"Eclessia" y "Christianitas" en Inocencio III

Abstract not availabl

Wavelet transform-based damage identification in laminated composite beams

Laminated composite structures suffers from delamination, the detachment of the layers due to the rupture of the fiber-matrix interface, as their principal mode of failure. Differently from other damages, such as cracks, delaminations are often not visible on the surface causing a late detection and leading to sudden failures. To ensure that laminated composite structures operate flawlessly, precise monitoring methods are required. The present study proposes a damage index to identify delaminations in a laminated composite beam, yet, the development is based on a well-defined methodology. The proposed damage index is composed of a weighted sum of Discrete Wavelet Transform detail coefficients, obtained by applying the transform to the mode shapes of the structure. Numerical models of the beams with a stiffness reduction in limited areas to simulate damage, provided data for tuning the coefficients of the damage index by performing a mixture design analysis and a multiobjective optimization. After substantial results for identifying damage in numerical cases, the damage index efficiency was tested with real carbon fiber-reinforced polymer beams. The experimental specimens were manufactured with delaminations induced by embedding non-sticking films between the layers. Again, substantial results in identifying damaged were achieved. The damage index proved to be efficient to locate damage in almost all positions along the beam. It is important to emphasize that the proposed damage index is a no-baseline method, a method that does not require information of the pristine structure. Finally, this study performs a deep statistical analysis on the effects of damage characteristics, such as position and severity, in a damage identifying technique. The results of the analysis serves as basis for developing more sophisticated and optimized damage identifying methods.Agência 1Estruturas compostas laminadas sofrem de delaminação, o desprendimento das camadas devido à ruptura da interface fibra-matriz, como seu principal modo de falha. Diferentemente de outros danos, como rachaduras, delaminações muitas vezes não são visíveis na superfície causando uma detecção tardia e levando a falhas repentinas. Para garantir que o composto laminado estruturas operam perfeitamente, métodos de monitoramento precisos são necessários. O presente estudo propõe um índice de danos para identificar delaminações em uma viga composta laminada, ainda, o desenvolvimento é baseado em uma metodologia bem definida. O índice de danos proposto é composto de uma soma ponderada de coeficientes de detalhe da Transformada Wavelet Discreta, obtidos aplicando a transformação às formas modais da estrutura. Modelos numéricos do vigas com redução de rigidez em áreas limitadas para simular danos, dados fornecidos para ajustar os coeficientes do índice de danos, realizando uma análise de projeto de mistura e um otimização multiobjetivo. Após resultados substanciais para identificação de danos em números casos, a eficiência do índice de dano foi testada com polímero reforçado com fibra de carbono real feixes. Os espécimes experimentais foram fabricados com delaminações induzidas por incorporação de filmes anti-aderentes entre as camadas. Novamente, resultados substanciais na identificação danificados foram alcançados. O índice de danos provou ser eficiente para localizar danos em quase todas as posições ao longo da viga. É importante ressaltar que a proposta índice de danos é um método sem linha de base, um método que não requer informações do estrutura primitiva. Finalmente, este estudo realiza uma análise estatística profunda sobre os efeitos da características do dano, como posição e gravidade, em uma técnica de identificação de dano. Os resultados da análise servem de base para o desenvolvimento mais sofisticado e otimizado métodos de identificação de danos