Ideal codes over separable ring extensions

This paper investigates the application of the theoretical algebraic notion of a separable ring extension, in the realm of cyclic convolutional codes or, more generally, ideal codes. We work under very mild conditions, that cover all previously known as well as new non trivial examples. It is proved that ideal codes are direct summands as left ideals of the underlying non-commutative algebra, in analogy with cyclic block codes. This implies, in particular, that they are generated by an idempotent element. Hence, by using a suitable separability element, we design an efficient algorithm for computing one of such idempotents

Evaluación de la toma de perspectiva en la esquizofrenia a través de la Teoría de los Marcos Relacionales: el papel de la introducción de ayudas contextuales

El presente estudio pretende evaluar la toma de perspectiva en personas con esquizofrenia a través de una tarea de respuesta relacional deíctica y un test de atribución de estados mentales. Participaron doce personas con diagnóstico de esquizofrenia y doce personas sin diagnóstico clínico. Los resultados revelaron la presencia de diferencias estadísticamente significativas en la ejecución de estas tareas. Los efectos de grupo permanecieron significativos tras examinar los posibles efectos del CI. La actuación en la tarea de respuesta relacional deíctica no permitió predecir de manera consistente la ejecución en la tarea de atribución de estados mentales en ambos grupos. Se discuten estos resultados, y se proponen líneas de estudio que supongan un avance hacia la conceptuación de la atribución de estados mentales en términos de la Teoría de los Marcos Relacionales (RFT).The present study aims to assess perspective taking in people with schizophrenia through a deictic relational response task and a test of mental state attribution. The sample was composed by twelve people diagnosed with schizophrenia and twelve people without clinical diagnosis. The results revealed the presence of statistically significant differences in the execution of these tasks. The effects of group remained significant after considering the possible effects of CI. The acting in the deictic relational response task did not allow consistently predict the performance in the task of mental state attribution in both groups. We discuss these results, and suggests lines of study that advance towards the conceptualization of mental state attribution in terms of Relational Frame Theory (RFT)

Predicting failure times of coherent systems

The article is focused on studying how to predict the failure times of coherent systems from the early failure times of their components. Both the cases of independent and dependent components are considered by assuming that they are identically distributed (homogeneous components). The heterogeneous components' case can be addressed similarly but more complexly. The present study is for non-repairable systems, but the information obtained could be used to decide if a maintenance action should be carried out at time (Formula presented.). Different cases are considered regarding the information available at time (Formula presented.). We use quantile regression techniques to predict the system failure times and to provide prediction intervals. The theoretical results are applied to specific system structures in some illustrative examples.18 página