Failure root causes analysis of complex systems—Dynamic Fault Tree approach

International audienceIn this paper we propose a methodology for the identification of the root causes of the failures of a complex dynamic system based on its Dynamic Fault Tree (DFT) and the component’s execution traces leading to the system’s malfunction. The proposed method is decomposed as follows: each basic event in the DFT is associated to its execution trace and a post-order depth-first traversal of the DFT is applied. Computing the failure-time and the failure root causes of each node of the DFT is done during the traversal of the DFT. As result, the failure root causes of the dynamic complex system is obtained in the top event of the DFT. The methodology is illustrated on an academic example

Retalho de Karapandzic e retalho de Bernard-Burrow-Webster na reconstrução do lábio inferior Karapandzic flap and Bernard-Burrow-Webster flap for reconstruction of the lower lip

O carcinoma de células escamosas é a neoplasia maligna mais frequente dos lábios, e em cerca de 90% dos casos, localiza-se no lábio inferior, por causa da maior exposição cumulativa à radiação ultravioleta. Os autores apresentam duas técnicas cirúrgicas para a reconstrução de grandes defeitos do lábio inferior, resultantes da excisão cirúrgica tumoral, exemplificando-as e comparando-as através de dois casos clínicos<br>Squamous cell carcinoma is the most common malignant neoplasm of the lips, and in about 90% of cases it is located on the lower lip due to higher cumulative exposure to ultraviolet radiation. The authors present two surgical techniques for reconstruction of large lower lip defects, resulting from surgical excision of tumors, exemplifying and comparing them with two clinical case

Generation of Test Data Structures Using Constraint Logic Programming

The goal of Bounded-Exhaustive Testing (BET) is the automatic generation of all the test cases satisfying a given invariant, within a given bound. When the input has a complex structure, the development of correct and efficient generators becomes a very challenging task. In this paper we use Constraint Logic Programming (CLP) to systematically develop generators of structurally complex test data. Similarly to filtering -based test generation, we follow a declarative approach which allows us to separate the issue of (i) defining the test structure and invariant, from that of (ii) generating admissible test input instances. This separation helps improve the correctness of the developed test case generators. However, in contrast with filtering approaches, we rely on a symbolic representation and we take advantage of efficient search strategies provided by CLP systems for generating test instances. Through some experiments on examples taken from the literature on BET, we show that CLP, by combining the use of constraints and recursion, allows one to write intuitive and easily understandable test generators. We also show that these generators can be much more efficient than those built using ad-hoc filtering-based test generation tools like Korat

Evaluación de hemerotecas de prensa digital: indicadores y ejemplos de buenas prácticas

La gran mayoría de los diarios digitales facilitan el acceso a la información retrospectiva mediante servicios de hemerotecas o archivos de prensa, un producto de notable interés para bibliotecas y otros servicios de información. El objetivo de este estudio es determinar cuáles son los indicadores fundamentales para la evaluación de hemerotecas digitales y, además, señalar ejemplos de buenas prácticas en España para cada uno de ellos. Se propone una relación de veintisiete indicadores agrupados en cuatro grandes apartados (aspectos generales, contenidos, sistema de consulta, y presentación de resultados), se describe cada uno de ellos y se incluye algún ejemplo de buena aplicación. Metodológicamente, se ha partido de la revisión de la bibliografía especializada en evaluación de recursos web, bases de datos y hemerotecas digitales, así como del análisis de hemerotecas de diarios de España y Catalunya. La utilización de estos indicadores puede ser de utilidad para que bibliotecas y otros servicios de información puedan orientar a sus usuarios en la consulta retrospectiva de información de prensa