Automatic March tests generation for static and dynamic faults in SRAMs

New memory production modern technologies introduce new classes of faults usually referred to as dynamic memory faults. Although some hand-made March tests to deal with these new faults have been published, the problem of automatically generate March tests for dynamic faults has still to be addressed, in this paper we propose a new approach to automatically generate March tests with minimal length for both static and dynamic faults. The proposed approach resorts to a formal model to represent faulty behaviors in a memory and to simplify the generation of the corresponding tests

Criticality analysis for improving maintenance, felling and pruning cycles in power lines

16th IFAC Symposium on Information Control Problems in Manufacturing INCOM 2018 Bergamo, Italy, 11–13 June 2018. Edited by Marco Macchi, László Monostori, Roberto PintoThis paper deals with the process of criticality analysis in overhead power lines, as a tool to improve maintenance, felling & pruning programs. Felling & pruning activities are tasks that utility companies must accomplish to respect the servitudes of the overhead lines, concerned with distances to vegetation, buildings, infrastructures and other networks crossings. Conceptually, these power lines servitudes can be considered as failure modes of the maintainable items under our analysis (power line spans), and the criticality analysis methodology developed, will therefore help to optimize actions to avoid these as other failure modes of the line maintainable items. The approach is interesting, but another relevant contribution of the paper is the process followed for the automation of the analysis. Automation is possible by utilizing existing companies IT systems and databases. The paper explains how to use data located in Enterprise Assets Management Systems, GIS and Dispatching systems for a fast, reliable, objective and dynamic criticality analysis. Promising results are included and also discussions about how this technique may result in important implications for this type of businesse

Automatism is never a defence

The central aim of this article is to set out and justify the contention that automatism is never a defence, not even exceptionally. Where D is not at fault for her lack of voluntariness, the term ‘automatism’ is simply a shorthand explanation that D does not satisfy an essential element of every offence: voluntary conduct. Where D is at fault for her lack of voluntariness, the automatism rules (within the current law) become an inculpatory tool through which to substitute the missing offence elements and construct liability. Having recognised that automatism plays an inculpatory role within the law, we analyse this role and conclude that it is defective: prior fault automatism lacks the equivalent blameworthiness necessary to fairly substitute for even missing basic intent offence elements. It is from here that we discuss the possibility of a new automatism offence, to recognise the criminal blameworthiness of D’s conduct in certain cases, but to do so in a coherent manner that appropriately criminalises and labels the defendant. Looking at the outline of the potential new offence we are in a much better position to evaluate the future role of automatism in the criminal law. If we do not believe that such an offence is deserving of criminalisation, then the current law must be changed to prevent prior fault automatism constructing liability under any circumstances. If we do believe that such an offence has a place within the criminal law, then the current law should be changed to reflect this more clearly, and we must focus on exactly how it should be defined

FORTEST: Formal methods and testing

Formal methods have traditionally been used for specification and development of software. However there are potential benefits for the testing stage as well. The panel session associated with this paper explores the usefulness or otherwise of formal methods in various contexts for improving software testing. A number of different possibilities for the use of formal methods are explored and questions raised. The contributors are all members of the UK FORTEST Network on formal methods and testing. Although the authors generally believe that formal methods are useful in aiding the testing process, this paper is intended to provoke discussion. Dissenters are encouraged to put their views to the panel or individually to the authors

On Modelling and Analysis of Dynamic Reconfiguration of Dependable Real-Time Systems

This paper motivates the need for a formalism for the modelling and analysis of dynamic reconfiguration of dependable real-time systems. We present requirements that the formalism must meet, and use these to evaluate well established formalisms and two process algebras that we have been developing, namely, Webpi and CCSdp. A simple case study is developed to illustrate the modelling power of these two formalisms. The paper shows how Webpi and CCSdp represent a significant step forward in modelling adaptive and dependable real-time systems.Comment: Presented and published at DEPEND 201

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

A Systematic Aspect-Oriented Refactoring and Testing Strategy, and its Application to JHotDraw

Aspect oriented programming aims at achieving better modularization for a system's crosscutting concerns in order to improve its key quality attributes, such as evolvability and reusability. Consequently, the adoption of aspect-oriented techniques in existing (legacy) software systems is of interest to remediate software aging. The refactoring of existing systems to employ aspect-orientation will be considerably eased by a systematic approach that will ensure a safe and consistent migration. In this paper, we propose a refactoring and testing strategy that supports such an approach and consider issues of behavior conservation and (incremental) integration of the aspect-oriented solution with the original system. The strategy is applied to the JHotDraw open source project and illustrated on a group of selected concerns. Finally, we abstract from the case study and present a number of generic refactorings which contribute to an incremental aspect-oriented refactoring process and associate particular types of crosscutting concerns to the model and features of the employed aspect language. The contributions of this paper are both in the area of supporting migration towards aspect-oriented solutions and supporting the development of aspect languages that are better suited for such migrations.Comment: 25 page

Beyond Good and Evil: Formalizing the Security Guarantees of Compartmentalizing Compilation

Compartmentalization is good security-engineering practice. By breaking a large software system into mutually distrustful components that run with minimal privileges, restricting their interactions to conform to well-defined interfaces, we can limit the damage caused by low-level attacks such as control-flow hijacking. When used to defend against such attacks, compartmentalization is often implemented cooperatively by a compiler and a low-level compartmentalization mechanism. However, the formal guarantees provided by such compartmentalizing compilation have seen surprisingly little investigation. We propose a new security property, secure compartmentalizing compilation (SCC), that formally characterizes the guarantees provided by compartmentalizing compilation and clarifies its attacker model. We reconstruct our property by starting from the well-established notion of fully abstract compilation, then identifying and lifting three important limitations that make standard full abstraction unsuitable for compartmentalization. The connection to full abstraction allows us to prove SCC by adapting established proof techniques; we illustrate this with a compiler from a simple unsafe imperative language with procedures to a compartmentalized abstract machine.Comment: Nit