@techreport{atr51,
    author      =   {Stefan Ratschan and Jan-Georg Smaus}, 
    title       =   {Finding Errors of Hybrid Systems by Optimising 
                     an Abstraction-Based Quality Estimate},
    editor      =   {Bernd Becker and Werner Damm and Martin Fr{\"a}nzle and
                     Ernst-R{\"u}diger Olderog and Andreas Podelski and Reinhard
                     Wilhelm},
    institution =   {SFB/TR 14 AVACS},
    subproject  =   {H1/2},
    year        =   {2009},
    month       =   {},
    type        =   {Reports of SFB/TR 14 AVACS},
    series      =   {ATR},
    number      =   51,
    note        =   {ISSN: 1860-9821, http://www.avacs.org.},
    access      =   {open},
    abstract    = {We present an algorithm for falsifying safety
                   properties of hybrid systems, i.e., for finding a
                   trajectory to an unsafe state.  The approach is to
                   approximate how close a point is to being an
                   initial point of an error trajectory using a
                   real-valued quality function, and then to use
                   numerical optimisation to search for an optimum of
                   this function. The function is computed by running
                   simulations, where information coming from
                   abstractions computed by a verification algorithm
                   is exploited to determine whether a simulation
                   looks promising and should be continued or
                   cancelled. This information becomes more reliable
                   as the abstraction becomes more refined. We thus
                   interleave falsification and verification
                   attempts. In contrast to related work, we
                   consider hybrid systems with completely
                   deterministic evolution.}, 
    bibtex = {atr051.bib},
    pdf = {avacs_technical_report_051.pdf} 
}