5 research outputs found
An Object-Oriented Framework for Explicit-State Model Checking
This paper presents a conceptual architecture for an object-oriented framework to support the development of formal veriļ¬cation tools (i.e. model checkers). The objective of the architecture is to support the reuse of algorithms and to encourage a modular design of tools. The conceptual framework is accompanied by a C++ implementation which provides reusable algorithms for the simulation and veriļ¬cation of explicit-state models as well as a model representation for simple models based on guard-based process descriptions. The framework has been successfully used to develop a model checker for a subset of PROMELA
Modelling laser-atom interactions in the strong field regime
We consider the ionisation of atomic hydrogen by a strong infrared field. We
extend and study in more depth an existing semi-analytical model. Starting from
the time-dependent Schroedinger equation in momentum space and in the velocity
gauge we substitute the kernel of the non-local Coulomb potential by a sum of N
separable potentials, each of them supporting one hydrogen bound state. This
leads to a set of N coupled one-dimensional linear Volterra integral equations
to solve. We analyze the gauge problem for the model, the different ways of
generating the separable potentials and establish a clear link with the strong
field approximation which turns out to be a limiting case of the present model.
We calculate electron energy spectra as well as the time evolution of electron
wave packets in momentum space. We compare and discuss the results obtained
with the model and with the strong field approximation and examine in this
context, the role of excited states.Comment: 11 pages, 5 figure
Gossiping Girls Are All Alike
Abstract. This paper discusses several different ways to model the wellknowngossiping girls probleminpromela.Thehighlysymmetricnature of the problem is exploited using plain promela, topspin (an extension to Spin for symmetry reduction), and by connecting Spin to bliss (a tool to computecanonicalrepresentationsofgraphs).Themodel checkerSpin is used to compare the consequences of the various modelling choices. This ā tutorial style ā paper is meant as a road map of the various ways of modelling symmetric systems that can be explored.