Analytical models for IEEE 802.11-based WLANs are invariably based on approximations, such as the well-known decoupling approximation proposed by Bianchi for modeling single cell WLANs consisting of saturated nodes. In this paper, we provide a new approach to model the situation when the nodes are not saturated. We study a State Dependent Attempt Rate (SDAR) approximation to model M queues (one...

We present a randomized distributed approximation algorithm for the metric uncapacitated facility location problem. The algorithm is executed on a bipartite graph in the CONGEST model yielding a (1.861+ ε) approximation factor, where ε is an arbitrary small positive constant. It needs O(n3/4 log1+ε(n)) communication rounds with high probability (n denoting the number of facilities and clients)....

We consider the assignment problem between two sets of $N$ random points on a smooth, two-dimensional manifold $\Omega$ unit area. It is known that average cost scales as $E_{\Omega}(N)\sim\frac{1}{2\pi}\ln N$ with correction at most order $\sqrt{\ln N\ln\ln N}$. In this paper, we show that, within linearization approximation field-theoretical formulation problem, first $\Omega$-dependent const...

We present an asymptotic fully polynomial approximation scheme for strip-packing, or packing rectangles into a rectangle of xed width and minimum height, a classical NP-hard cutting-stock problem. The algorithm nds a packing of n rectangles whose total height is within a factor of (1 +) of optimal (up to an additive term), and has running time polynomial both in n and in 1==. It is based on a r...

This paper introduces a Parseval frame of shearlets for the representation of 3D data, which is especially designed to handle geometric features such as discontinuous boundaries with very high efficiency. This system of 3D shearlets forms a multiscale pyramid of well-localized waveforms at various locations and orientations, which become increasingly thin and elongated at fine scales. We prove ...

We present a new approximation algorithm for the treewidth problem which constructs corresponding tree decomposition as well. Our is faster variation of Reed's classical algorithm. For benefit reader, and to be able compare these two algorithms, we start with detailed time analysis fill in many details that have been omitted paper. Computing decompositions parameterized by $k$ fixed parameter t...

the present research attempts to explain dynamic pull-in instability of functionally graded micro-cantilevers actuated by step dc voltage while the fringing-field effect is taken into account in the vibrational equation of motion. by employing modern asymptotic approach namely homotopy perturbation method with an auxiliary term, high-order frequency-amplitude relation is obtained, then the infl...

We use an approximation scheme together with a variation of the fixed point theorem to show existence positive solution nonlocal boundary value problem. This problem has smooth bounded domain in R<sup>N</sup>, singular term, and combined nonlinearities. also study symmetric, monotonicity, asymptotic behavior solutions respect parameter involved