For each digraph with at most 5 vertices, we provide a list of its polymorphisms interesting with respect to the complexity of the corresponding Constraint Satisfaction Problem. We find a digraph on six vertices such that the complexity of its retraction problem is unknown with current techniques; this is the smallest such example. AMS Mathematics Subject Classification (2000): 05C85, 68R10, 08A70

This paper is a survey of several results concerning finite dualities, a special case of the famous Constraint Satisfaction Problem (CSP). In CSP, the point is to characterize a class C of objects X determined by constraints represented by the requirement of the existence of structure preserving mappings from X into special ones. In a finite duality, such a class C is characterized by the non-e...

This paper presents an algorithm based on multi-objective approach for network reconfiguration. Multiple objectives are considered for reduction in the system power loss, deviations of the nodes voltage and transformers loading imbalance, while subject to a radial network structure in which all the loads must be energized and no branch current constraint is violated. These three objectives are ...

The paper considers several optimization problem statements for signal sparse reconstruction problems. We tested performance of AORDA Portfolio Safeguard (PSG) package with different problem formulations. We solved several medium-size test problems with cardinality functions: (a) minimize L1-error of regression subject to a constraint on cardinality of the solution vector; (b) minimize cardinal...

In this paper we propose a lazy constraint imposing mechanism for improving the path constraint in GRASPER, a state-of-the-art graph constraint solver, having obtained very promising results in terms of both time and space in solving an interesting problem in the Biochemistry subject area, in comparison with CP(Graph), the state-of-the-art solver.

Abstract This paper addresses the noncooperative attitude tracking control problem for rigid bodies whose dynamics evolves on rotation matrix . First, based relative measurement, a saturated angular velocity input is designed by proposed nonlinear function. Thereafter, torque body's with saturation constraint and active disturbance rejection developed modified dynamic surface approach which can...

An amended MaxEnt formulation for systems displaced from the conventional MaxEnt equilibrium is proposed. This formulation involves the minimization of the Kullback-Leibler divergence to a reference Q (or maximization of Shannon Q-entropy), subject to a constraint that implicates a second reference distribution P1 and tunes the new equilibrium. In this setting, the equilibrium distribution is t...

the realization optimality theory is a recent development in the original optimality theory which is proposed to deal with morphological issues especially the inflectional ones. its main idea is to consider the morphological realization rules as ranked violable language-specific constraints that control the realization processes and provide phonological information of grammatical morphemes. thi...