VLSI chips design is becoming increasingly complex and calling for more and more automation. Many chip design problems can be formulated naturally as constraint problems and are potentially amenable to CP techniques. To the best of our knowledge, though, there has been little CP work in this domain to date. We describe a successful application of a CP based tool to a particular pin-assignment p...

ion of φ and the “invisible” part τp is (the Boolean abstraction of) the set of the T -lemmas providing the obligations induced by the theory T on the atoms of φ. (We use the superscript p to denote the Boolean abstraction of a T -formula.) To this extent, a traditional “lazy” SMT solver can be seen as a DPLL solver which knows φp but not τp: whenever a model μp for φp is found, it is passed to...

We observed that Conjunctive Normal Form (CNF) encodings of structured SAT instances often have a set of consecutive clauses defined over a small number of Boolean variables. To exploit the pattern, we propose a transformation of CNF to an alternative representation, Conjunctive Minterm Canonical Form (CMCF). The transformation is a two-step process: CNF clauses are first partitioned into disjo...

This article describes some of the capabilities encapsulated within the Model Independent Calibration and Uncertainty Analysis Toolbox (MICUT), which was written to support the popular PEST model independent interface. We have implemented a secant version of the Levenberg–Marquardt (LM) method that requires far fewer model calls for local search than the PEST LM methodology. Efficiency studies ...

The MAX-SAT problem is to find a truth assignment that satisfies the maximum number of clauses in a finite set of logical clauses. In the special case of MAX-XOR-SAT, arising from Linear Cryptanalysis, each clause is a set of literals joined by exclusive-or (xor). Solving MAX-XOR-SAT is useful in finding keys to decrypt intercepted encrypted messages. This report presents and evaluates Xor-Walk...

A dominant approach to Satisfiability Modulo Theories (SMT) relies on the integration of a Conflict-Driven-Clause-Learning (CDCL) SAT solver and of a decision procedure able to handle sets of atomic constraints in the underlying theory T (T -solver). In pure SAT, however, Stochastic Local-Search (SLS) procedures sometimes are competitive with CDCL SAT solvers on satisfiable instances. Thus, it ...

Falsification techniques for models of embedded control systems automate the process of testing models to find bugs by searching for model-inputs that violate behavioral specifications given by logical and quantitative correctness requirements. A recent advance in falsification is to encode property satisfaction as a cost function based on a finite parameterization of the (bounded-time) input s...

The Genomic Median Problem is an optimization problem inspired by a biological issue: it aims at finding the genome organization of the common ancestor to multiple living species. It is formulated as the search for a genome that minimizes some distance measure among given genomes. Several attempts have been made at solving the problem. These range from simple heuristic methods to a stochastic l...

Many stochastic local search (SLS) methods rely on the manipulation of single solutions at each of the search steps. Examples are iterative improvement, iterated local search, simulated annealing, variable neighborhood search, and iterated greedy. These SLS methods are the basis of many state-of-the-art algorithms for hard combinatorial optimization problems. Often, several of these SLS methods...