Quasi-stationarity and time to extinction are studied for the classic endemic model. Attention is restricted to the transition region in parameter space where the quasi-stationary distribution is non-normal. A new approximation of the marginal distribution of infected individuals in quasi-stationarity is presented. It leads to a simple explicit expression for an approximation of the critical co...

Abstract When X is locally compact, a quasi-integral (also called quasi-linear functional) on $$ C_c(X)$$ C c ( X ) homogeneous, positive functional that only assumed to be linear singly-generated...

The frequency dependence of the effective permittivities of simple dielectric composites is evaluated by different quasidynamic homogenization methods. Three retrieval approaches based on the scattering parameters are proposed for dielectric materials. A compensation method for the conventional Nicolson-Ross-Weir (NRW) retrieval is applied to eliminate the FabryPérot (FP) resonances and their d...

we shall be concerned with the problem of determining quasi-stationary distributions for Markovian models directly from their transition rates Q. We shall present simple conditions for a p-invariant measure m for Q to be p-invariant for the transition function, so that if m is finite, it can be normalized to produce a quasi-stationary distribution. @ 2000 Elsevier Science Ltd. All rights reserv...

We introduce Quasi-Threshold Mover (QTM), an algorithm to solve the quasi-threshold (also called trivially perfect) graph editing problem with a minimum number of edge insertions and deletions. Given a graph it computes a quasi-threshold graph which is close in terms of edit count, but not necessarily closest as this edit problem is NP-hard. We present an extensive experimental study, in which ...

The quasi-bound modes localized on stable periodic ray orbits of dielectric micro-cavities are constructed in the short-wavelength limit using the parabolic equation method. These modes are shown to coexist with irregularly spaced ???chaotic??? modes for the generic case. The wavevector quantization rule for the quasi-bound modes is derived and given a simple physical interpretation in terms of...