Grammar semantics, analysis and parsing by abstract interpretation

We study abstract interpretations of a fixpoint protoderivation semantics defining the maximal derivations of a transitional semantics of context-free grammars akin to pushdown automata. The result is a hierarchy of bottom-up or top-down semantics refining the classical equational and derivational language semantics and including Knuth grammar problems, classical grammar flow analysis algorithms and parsing algorithms.     

Growth temperature impact on MOVPE-grown BInGaAs/GaAs QWs designed for optoelectronic applications

Journal of Materials Science: Materials in Electronics - In this work, quaternary BInGaAs single quantum wells have been grown on GaAs substrate by metal–organic vapor-phase epitaxy. The...     

Environmental impacts of single and successive breakwaters along the Mediterranean coastline at Radès–Ezzahra, NE Tunisia

The coastline between Radès and Ezzahra, NE Tunisia, suffered from erosion during a strong storm in 1981. As a consequence, between 1985 and 1988, a single breakwater was constructed in Radès and two successive breakwaters in Ezzahra. The paper reports a study of the effectiveness of these structures and considers the other factors which influence the accretion/erosion of the shoreline.     

Why does <Emphasis Type="SmallCaps">Astrée</Emphasis> scale up?

Astrée was the first static analyzer able to prove automatically the total absence of runtime errors of actual industrial programs of hundreds of thousand lines. What makes Astrée such an innovative tool is its scalability, while retaining the required precision, when it is used to analyze a specific class of programs: that of reactive control-command software. In this paper, we discuss the important choice of algorithms and data-structures we made to achieve this goal. However, what really made this task possible was the ability to also take semantic decisions, without compromising soundness, thanks to the abstract interpretation framework. We discuss the way the precision of the semantics was tuned in Astrée in order to scale up, the differences with some more academic approaches and some of the dead-ends we explored. In particular, we show a development process which was not specific to the particular usage Astrée was built for, hoping that it might prove helpful in building other scalable static analyzers.     

Bi-inductive Structural Semantics: (Extended Abstract)

We propose a simple order-theoretic generalization of set-theoretic inductive definitions. This generalization covers inductive, co-inductive and bi-inductive definitions and is preserved by abstraction. This allows the structural operational semantics to describe simultaneously the finite/terminating and infinite/diverging behaviors of programs. This is illustrated on the structural bifinitary small/big-step trace/relational/operational semantics of the call-by-value λ-calculus.     

An Improved Polytopic Adaptive LPV Observer Design Under Actuator Fault

In this paper, we treat the problem of both state estimation and fault detection of nonlinear systems. Those systems could be described by a poly-quadratic Linear Parameter-Varying (LPV) form. A new adaptive observer is developed in terms of Linear Matrix Inequalities (LMI) technique. A feasible algorithm is developed to compute the designed parameters. This algorithm provides more flexibility and mitigates the conservatism of quadratic approach. Finally, simulation results are presented to illustrate the efficiency of the proposed method..     

Environmental impacts of single and successive breakwaters along the Mediterranean coastline at Radès–Ezzahra, NE Tunisia

The coastline between Radès and Ezzahra, NE Tunisia, suffered from erosion during a strong storm in 1981. As a consequence, between 1985 and 1988 a single breakwater was constructed in Radès and two successive breakwaters in Ezzahra. The paper reports a study of the effectiveness of these structures and considers the other factors which influence the accretion/erosion of the shoreline.     

Refining Model Checking by Abstract Interpretation

Formal methods combining abstract interpretation and model-checking have been considered for automated analysis of software.In abstract model-checking, the semantics of an infinite transition system is abstracted to get a finite approximation on which temporal-logic/-calculus model-checking can be directly applied.The paper proposes two improvements of abstract model-checking which can be applied to infinite abstract transition systems:iA new combination of forwards and backwards abstract fixed-point model-checking computations for universal safety. It computes a more precise result than that computed by conjunction of the forward and backward analyses alone, without needing to refine the abstraction;When abstraction is unsound (as can happen in minimum/maximum path-length problems), it is proposed to use the partial results of a classical combination of forward and backward abstract interpretation analyses for universal safety in order to reduce, on-the-fly, the concrete state space to be searched by model-checking.