Cocaine is a common drug of abuse. To detect its use, a screening detection concentration for the cocaine metabolite benzoylecgonine is commonly set at 150 ng/mL and its confirmatory cut-off is set at 100 ng/mL. Studies have suggested that these cut-offs may be set too high, allowing some patients with this substance abuse problem to be missed or improperly monitored. With the advent of liquid ...

In this paper we summarize recent results on finding tight semidefinite programming relaxations for the Max-Cut problem and hence tight upper bounds on its optimal value. Our results hold for every instance of Max-Cut and in particular we make no assumptions on the edge weights. We present two strengthenings of the well-known semidefinite programming relaxation of Max-Cut studied by Goemans and...

due to the importance of material classification issue in grinding circuits, the ‎performance of primary and secondary hydrocyclones in grinding circuit of esfordi ‎phosphate plant was investigated by sampling within 7 days from feed, overflow, and ‎underflow‎ of these hydrocyclones. at first, the d80 of above streams samples were calculated by ‎the screening analysis. the results showed ‎that ...

We consider the max-cut problem on a random graph G with n vertices and weights wij being independent bounded random variables with the same xed positive expectation and variance . It is well known that the max-cut number mc(G) always exceeds 2 ∑ i¡j wij . We prove that with probability greater than pn the max-cut number satis es

A short proof of a difficult theorem of P.D. Seymour on grafts with the max-flow min-cut property is given.

We study budgeted variants of classical cut problems: the Multiway Cut problem, the Multicut problem, and the k-Cut problem, and provide approximation algorithms for these problems. Specifically, for the budgeted multiway cut and the k-cut problems we provide constant factor approximation algorithms. We show that the budgeted multicut problem is at least as hard to approximate as the sparsest c...

We propose Inflate-Paste – a new technique for generating orthogonal polygons with a given number of vertices from a unit square based on gluing rectangles. It is dual to Inflate-Cut – a technique we introduced in [12] that works by cutting rectangles.