in this paper we study shadowing property for sequences of mappings on compact metric spaces, i.e. nonautonomous discrete dynamical systems. we investigate the relation of  weak contractions with shadowing and h-shadowing property.

postpartum depression (ppd) is a major depressive disorder that most often emerges within 6 to 12 weeks of delivery, but can happen any time up to 1 year after birth. in developed countries, the incidence of postnatal depression is about 10-15% in adult women depending upon the diagnostic criteria, timing of screening and screening instruments used. mothers with depressive symptoms have been fo...

This paper deals with solutions of algebraic, linear, and rational systems of equations over an !-complete semiring, and their iteration lemmata. These are guaranteed if the underlying structure has an associative multiplicative operation, and its elements have a norm. A number of such structures like words, vectors, traces, trees, graphs, are presented.

A framework of Plotkin and Turi’s, originally aimed at providing an abstract notion of bisimulation, is modified to cover other operational equivalences and preorders. Combined with bialgebraic methods, it yields a technique for the derivation of syntactic formats for transition system specifications which guarantee operational preorders to be precongruences. The technique is applied to the tra...

The paper investigates the realization problem for piecewise-affine discrete-time hybrid systems. A piecewise-affine discrete-time hybrid system is a discrete-time system such that the state-transition and readout maps are piecewise-affine maps. We will restrict our attention to autonomous systems and we will study the following realization problem. For a specified output trajectory, find a pie...

considering a temperature dependent two-level quantum system, we have numerically solved the landau-zener transition problem. the method includes the incorporation of temperature effect as a thermal noise added schrödinger equation for the construction of the hamiltonian. here, the obtained results which describe the changes in the system including the quantum states and the transition probabil...

In implementation verification, we check that an implementation is correct with respect to a specification by checking whether the behaviors of a transition system that models the program’s implementation correlate with the behaviors of a transition system that models its specification. In this paper, we investigate the effect of concurrency on the complexity of implementation verification. We ...