In this paper, we introduce and analyze a new cut-off priority scheme which provides a better grade-of-service to handoff traffic while maintaining high throughput for the originating calls. A hysteresis control is used for additional robustness. The system model is found to have a general level dependent Quasi-Birthand-Death (QBD) structure. An efficient solution methodology is used taking ful...

We present an accurate and efficient numerical method, based on integral Nyström discretizations, for the solution of three dimensional wave propagation problems in piece-wise homogeneous media that have two-dimensional (in-plane) periodicity (e.g. photonic crystal slabs). Our approach uses (1) A fast, high-order algorithm for evaluation of singular integral operators on surfaces in three-dimen...

In this paper we present the approximate waiting time analysis of two class non-preemptive priority queues. The traffics of the queue are characterized by ”two parameter description”, which means that the mean and the squared coefficient of variation of the inter arrival times and of the service times are given. The solution is based on the separate analysis of the low and high priority queue. ...

This paper describes a software implementation of Byrd and Omojokun’s trust region algorithm for solving nonlinear equality constrained optimization problems. The code is designed for the efficient solution of large problems and provides the user with a variety of linear algebra techniques for solving the subproblems occurring in the algorithm. Second derivative information can be used, but whe...

This paper suggests new queuing models, in the Markovian framework, which can tackle the presence of burstiness in the traffic and autocorrelations among the inter-arrival times of packets in the performance evaluation of next generation networks. These models are essentially based on certain generalizations of the Quasi Birth-Death (QBD) processes. Efficient steady state solution of these new ...

In this article, we present a solution to a class of Quasi-Birth-andDeath processes with finite state space and show that the stationary probability vector has a matrix geometric representation. We show that such models have a level-dependent rate matrix. The corresponding rate matrix is given explicitly in terms of the model parameters. The resulting closed-form expression is proposed as a bas...

A physics-based multi-cell electro-thermal equivalent circuit model is described which is applied to the large-signal microwave characterization of AlGaAs/GaAs HBTs. This highly efficient model, which incorporates a new multi-finger electro-thermal model, has been used to perform DC, small-signal and load-pull characterization and investigate parameter-spreads due to fabrication process variati...

We address the solution of convex constrained nonlinear systems by new linesearch Quasi-Newton methods. These methods are based on a proper use of the projection map onto the constraint set and on a derivativefree and nonmonotone linesearch strategy. The convergence properties of the proposed methods are presented along with a worst-case iteration complexity bound. Several implementations of th...

We consider finite element methods applied to a class of quasi parabolic integro-differential equations in R. Global strong superconvergence, which only requires that partitions are quasi-uniform, is investigated for the error between the approximate solution and the Sobolev-Volterra projection of the exact solution. Two order superconvergence results are demonstrated in W (Ω) and Lp(Ω), for 2 ...

The aim of this manuscript is to determine the relative size of several functions (copulas, quasi–copulas) that are commonly used in stochastic modeling. It is shown that the class of all quasi–copulas that are (locally) associated to a doubly stochastic signed measure is a set of first category in the class of all quasi–copulas. Moreover, it is proved that copulas are nowhere dense in the clas...