Narrowing and Unification in the Maude Programming Language

[ES] Los protocolos de seguridad en las comunicaciones evolucionan cada día buscando mejoras y corrección de errores, muchos de los cuales pueden llevar a vulnerabilidades con consecuencias fatales. Por ello, se vuelve de vital importancia el encontrar algoritmos y herramientas capaces de encontrar esas vulnerabilidades para poder solucio-narlas cuanto antes. Uno de estos algoritmos es el narrowing, implementado en Maude, un lenguaje utilizado por varias herramientas de análisis de protocolos, que, a pesar de ser potente y eficiente en muchos casos, tiene algunas limitaciones, que pueden ser resueltas mediante la utilización de variantes del algoritmo. Una posible variante es el canonical narrowing, que se basa en restricciones de irreductibilidad para descartar aquellas secuencias del narrowing estándar que pueden obviarse porque no representan secuencias de reescritura reales.[EN] Communications security protocols evolve every day seeking improvements and bug fixes, many of which can lead to vulnerabilities with fatal consequences. For this reason, it becomes vitally important to find algorithms and tools capable of finding these vulnerabilities in order to fix them as soon as possible. One of these algorithms is narrowing, implemented in Maude, a language used by various protocol analysis tools, which, despite being powerful and efficient in many cases, has some limitations, which can be resolved by using variants of the algorithm. A possible variant is canonical narrowing, which relies on irreducibility constraints to discard those sequences of the standard narrowing that can be ignored because they do not represent actual rewrite sequences.López Rueda, R. (2021). Narrowing and Unification in the Maude Programming Language. Universitat Politècnica de València. http://hdl.handle.net/10251/173970TFG

A Causal Analysis of Life Expectancy at Birth. Evidence from Spain

Background: From a causal point of view, there exists a set of socioeconomic indicators concerning life expectancy. The objective of this paper is to determine the indicators which exhibit a relation of causality with life expectancy at birth. Methods: Our analysis applies the Granger causality test, more specifically its version by Dumitrescu–Hurlin, starting from the information concerning life expectancy at birth and a set of socioeconomic variables corresponding to 17 Spanish regions, throughout the period 2006–2016. To do this, we used the panel data involving the information provided by the Spanish Ministry of Health, Consumer Affairs and Social Welfare (MHCSW) and the National Institute of Statistics (NIS). Results: Per capita income, and the rate of hospital beds, medical staff and nurses Granger-cause the variable “life expectancy at birth”, according to the Granger causality test applied to panel data (Dumitrescu–Hurlin’s version). Conclusions: Life expectancy at birth has become one of the main indicators able to measure the performance of a country’s health system. This analysis facilitates the identification of those factors which exhibit a unidirectional Granger-causality relationship with life expectancy at birth. Therefore, this paper provides useful information for the management of public health resources from the point of view of the maximization of social benefits