The Art of Fault Injection

Classical greek philosopher considered the foremost virtues to be temperance, justice, courage, and prudence. In this paper we relate these cardinal virtues to the correct methodological approaches that researchers should follow when setting up a fault injection experiment. With this work we try to understand where the "straightforward pathway" lies, in order to highlight those common methodological errors that deeply influence the coherency and the meaningfulness of fault injection experiments. Fault injection is like an art, where the success of the experiments depends on a very delicate balance between modeling, creativity, statistics, and patience

Fault Injection for Embedded Microprocessor-based Systems

Microprocessor-based embedded systems are increasingly used to control safety-critical systems (e.g., air and railway traffic control, nuclear plant control, aircraft and car control). In this case, fault tolerance mechanisms are introduced at the hardware and software level. Debugging and verifying the correct design and implementation of these mechanisms ask for effective environments, and Fault Injection represents a viable solution for their implementation. In this paper we present a Fault Injection environment, named FlexFI, suitable to assess the correctness of the design and implementation of the hardware and software mechanisms existing in embedded microprocessor-based systems, and to compute the fault coverage they provide. The paper describes and analyzes different solutions for implementing the most critical modules, which differ in terms of cost, speed, and intrusiveness in the original system behavio

A Self-Repairing Execution Unit for Microprogrammed Processors

Describes a processor which dynamically reconfigures its internal microcode to execute each instruction using only fault-free blocks from the execution unit. Working without redundant or spare computational blocks, this self-repair approach permits a graceful performance degradatio

Agent Based Test and Repair of Distributed Systems

This article demonstrates how to use intelligent agents for testing and repairing a distributed system, whose elements may or may not have embedded BIST (Built-In Self-Test) and BISR (Built-In Self-Repair) facilities. Agents are software modules that perform monitoring, diagnosis and repair of the faults. They form together a society whose members communicate, set goals and solve tasks. An experimental solution is presented, and future developments of the proposed approach are explore

DFT and BIST of a multichip module for high-energy physics experiments

Engineers at Politecnico di Torino designed a multichip module for high-energy physics experiments conducted on the Large Hadron Collider. An array of these MCMs handles multichannel data acquisition and signal processing. Testing the MCM from board to die level required a combination of DFT strategie

Gene expression classifiers and out-of-class samples detection

The proper application of statistics, machine learning, and data-mining techniques in routine clinical diagnostics to classify diseases using their genetic expression profile is still a challenge. One critical issue is the overall inability of most state-of-the-art classifiers to identify out-of-class samples, i.e., samples that do not belong to any of the available classes. This paper shows a possible explanation for this problem and suggests how, by analyzing the distribution of the class probability estimates generated by a classifier, it is possible to build decision rules able to significantly improve its performance

La urbanidad y la educación cívica como disciplinas escolares: relación e implicaciones

[Resumen] La urbanidad y la educación cívica han venido formando parte del modelo de educación adoptado para la infancia y la juventud en los dos últimos siglos. Ambas discipli- nas, junto a la moral, entre otras, han ido tejiendo el conjunto de virtudes cívicas que han caracterizado al buen ciudadano. Aunque tienen distinto origen y trayectoria curricular dife- renciada, han compartido fundamentos y contenidos, de manera que las imbricaciones entre una y otra disciplina han sido evidentes. En este artículo se analizan la relación e implicaciones entre dos materias escolares que tienen un campo semántico amplio y cam- biante a lo largo del tiempo, como son la urbanidad y la educación cívica. Mediante el aná- lisis de los libros escolares que vehiculan el código social en las escuelas primarias, se hace un estudio especial de las dimensiones o componentes de la urbanidad, estudio que pone de manifiesto la complementariedad de estos dos aprendizajes y los elementos com- partidos por ambas disciplinas.[Abstract] Etiquette and civic education have been part of the educational model taught to children and adolescents over the course of past two centuries. Both subjects, along with ethics, among others, have woven a fabric of civic virtues that have served to characterize the good citizen. While their origin and the trajectory of their curricula differ, these subjects have shared basic concepts and contents, so that the two are clearly intertwined. This arti- cle analyses the relationship and pertinent implications between two school subjects whose broad semantic field has undergone changes over the years- namely, etiquette and civic education. Through the analysis of the schoolbooks that serve to channel the social code in the primary schools, the article focuses on the dimensions or components of etiquette, high- lighting the way in which these two subjects complement each other and the elements they share

El libro en los inicios del sistema escolar contemporáneo

[Resumen] Este artículo trata de la problemática del libro escolar en el periodo en el que se conforma el sistema educativo español, especialmente en lo referente a la intervención política de que fue objeto este importante y todavía escaso recurso didáctico, y que llevó a consolidar el principio de "elección restringida" del libro de texto, ya la consiguiente acción emprendida por los pedagogos más influyentes de la época con el fin de orientar al magisterio primario en la importante función de elegir, entre las obras previamente aprobadas por el gobierno, el libro -o los libros- de uso en sus respectivas escuelas.[Abstract] This article deals with the issues surrounding school books in the period during which the Spanish school system was being formed, with special atlention being paid to the political control exerted upon this important educational tool, which is still in short supply. This policy led to the consolidation of the principie known as Irestricted selectionl of school texts and the resulting measures taken by the most influential educators of the time whose purpose it was to offer guidelines .to elementary school teachers in the important task of choosing the book or books from the government approved list, to be used in their respective schools

Texto y curriculum en la enseñanza secundaria. La producción de manuales para el bachillerato decimonónico en Galicia

[Resumen] El libro de texto constituye una luente de primer orden para la historia del bachi- llerato -y de las distintas disciplinas- en tanto es notoria su contribución a la construcción, con- solidación y desarrollo del curriculum en este nivel educativo. Partiendo de dos hechos evi- dentes: el control ejercido por la Administración sobre este importante producto escolar y la pro- gresiva intervención del prolesorado de secundaria en la elaboración de manuales, el presen- te artículo analiza la implicación de los prolesores de los institutos gallegos en la redacción de libros de texto para sus respectivas asignaturas en la segunda mitad del siglo XIX[Abstract] The textbook is one 01 the most important sources in the history 01 secondary edu- cation -and 01 the different disciplines-, while it has also made a noteworthy contribution to the composition, consolidation and development 01 lhe curriculum al this educationallevel. Based on obvious lacts: the control exerted by the Administration on this importan! educational ele- ment and the gradual intervention 01 the secondary school teachers in writing manuals, this arti- ele analyses the involvement 01 the teachers in Galician secondary schools in the writing 01 the textbooks lor their respective subjects during lhe second hall 01 the 19th century