Although situational judgment tests have a long history in the psychological assessment literature and continue to be frequently used in employment contexts, there has been virtually no summarization… (More)

We consider both autonomous and nonautonomous population models subject to either impulsive or continuous harvesting. It is demonstrated in the paper that the impulsive strategy can be as good as the… (More)

We study delay-independent stability in nonlinear models with a distributed delay which have a positive equilibrium. Such models frequently occur in population dynamics and other applications. In… (More)

1 Department of Mathematics and Statistics, University of Calgary, 2500 University Drive N.W., Calgary, Alberta T2N 1N4, Canada. E-mail: maelena@math.ucalgary.ca 2 The Academic College of Tel… (More)

l~(t) = r(t)N(t) a bkN(hk(t)) cz(t)N(gl(t)), t >_ O, l = l N(t )=~( t ) , t<O, N(O)=No, is considered. The existence and the bounds of positive solutions are studied. Sufficient conditions for the… (More)

we obtain existence, positiveness and permanence results for solutions with positive initial conditions. We prove that all nonoscillatory about the positive equilibrium N solutions tend to N. In the… (More)

We obtain linearized oscillation theorems for the equation with distributed delays ẋ(t)+ m ∑ k=1 rk(t) ∫ t −∞ fk(x(s)) ds Rk(t, s) = 0. (1) The results are applied to logistic, Lasota–Wazewska and… (More)

New explicit conditions of exponential stability are obtained for the nonautonomous equation with several delays ẏ(t)+ l ∑ k=1 ak(t)y ( hk(t) ) = 0 by the following method: several delays in the… (More)