many simulation algorithms (chemical reaction systems, differential systems arising from the modeling of transient behavior in the process industries and etc.) contain the numerical solution of systems of differential equations. for the efficient solution of the above mentioned problems, linear multistep methods or runge-kutta technique are used. for the simulation of chemical procedures the ra...

the computation of the inverse roots of matrices arises in evaluating non-symmetriceigenvalue problems, solving nonlinear matrix equations, computing some matrixfunctions, control theory and several other areas of applications. it is possible toapproximate the matrix inverse pth roots by exploiting a specialized version of new-ton's method, but previous researchers have mentioned that some...

In this study, we measured via surgical sampling hepatic EROD activity in yellow-legged gulls from oiled and unoiled colonies, 17 months after the Prestige oil spill. We also analyzed stable isotope composition in feathers of the biopsied gulls, in an attempt to monitor oil incorporation into marine food web. We found that yellow-legged gulls in oiled colonies were being exposed to remnant oil ...

Proton pumping P systems are a variant of membrane systems with both rewriting rules and symport/antiport rules, where a set of objects called protons is distinguished, every cooperative symport or antiport rule involves a proton, but no rewriting rule does. Time-freeness property means the result of all computations does not depend on the time it takes to execute the rules. The goal of this ar...

In this paper we study two-sided matching markets in which the participants do not fully know their preferences and need to go through some costly deliberation process in order to learn their preferences. We assume that such deliberations are carried out via interviews, thus the problem is to find a good strategy for interviews to be carried out in order to minimize their use, whilst leading to...

In this paper we investigate the complexity of problems concerned with approximating the stable model semantics. We show that under rather weak assumptions it is NP-hard to decide whether the size of a polynomially computable approximation is within a constant factor from the size of the intersection (union) of stable models of a program. We also show that unless P=NP, no approximation exists t...

We introduce two refinements of the neutral stability criterion, namely the ascending and the eroding neutrally stable strategies (NSS). These criteria take into account how well the NSS preform against all pure strategies in symmetric two-player games. We also present a dynamic model which supports the refinements.