18 research outputs found
Профиль российской бедности: факторы и риски для работающего населения
Выявлены факторы и соответствующие им риски возникновения бедности среди работающего населения России. Доказывается, что причины возникновения бедности лежат в плоскости экономического развития страны: особенностей прохождения экономических циклов на волне спада и кризиса, качества экономического роста на волне подъема. Выработаны направления стратегии качественного экономического роста страны для преодоления бедности работающего населения
A Lazy SMT-Solver for a Non-Linear Subset of Real Algebra
There are several methods for the synthesis and analysis of hybrid
systems that require efficient algorithms and tools for satisfiability
checking. For analysis, e.g., bounded model checking describes
counterexamples of a fixed length by logical formulas, whose
satisfiability corresponds to the existence of such a counterexample.
As an example for parameter synthesis, we can state the correctness of
a parameterized system by a logical formula; the solution set of
the formula gives us possible safe instances of the parameters.
For discrete systems, which can be described by propositional logic
formulas, SAT-solvers can be used for the satisfiability checks. For
hybrid systems, having mixed discrete-continuous behavior, SMT-solvers
are needed. SMT-solving extends SAT with theories, and has its main
focus on linear arithmetic, which is sufficient to handle, e.g.,
linear hybrid systems. However, there are only few solvers for
more expressive but still decidable logics like the
first-order theory of the reals with addition and multiplication --
real algebra. Since the synthesis and analysis of non-linear
hybrid systems requires such a powerful logic, we need efficient
SMT-solvers for real algebra. Our goal is to develop such an
SMT-solver for the real algebra, which is both complete and
efficient
Accelerating Parametric Probabilistic Verification
We present a novel method for computing reachability probabilities of
parametric discrete-time Markov chains whose transition probabilities are
fractions of polynomials over a set of parameters. Our algorithm is based on
two key ingredients: a graph decomposition into strongly connected subgraphs
combined with a novel factorization strategy for polynomials. Experimental
evaluations show that these approaches can lead to a speed-up of up to several
orders of magnitude in comparison to existing approache
Integrating virtual substitution into strategic SMT solving
This thesis addresses the integration of real algebraic procedures as theory solvers into satisfiability modulo theories (SMT) solvers, in order to check non-linear real- and integer-arithmetic formulas for satisfiability. There are plenty of procedures to choose from and we aim for a general framework that allows us to select and combine them. The main part of this thesis concerns one specific example of the aforementioned integration: the virtual substitution method. Here we also optimize this method with respect to satisfiability checking and extend it such that it can be used for integer arithmetic