We present two approaches for computing rational approximations to multivariate functions, motivated by their effectiveness as surrogate models high-energy physics (HEP) applications. Our first approach builds on the Stieltjes process efficiently and robustly compute coefficients of approximation. second is based an optimization formulation that allows us include structural constraints approxim...

In the hitting set problem one is given m subsets of a nite set N and one has to nd an X N of minimum cardinality that \hits" (intersects) all of them. The problem is NP-hard. It is not known whether there exists a polynomial-time approximation algorithm for the hitting set problem with a nite performance ratio. Special cases of the hitting set problem are described for which nite performance r...

Increasing global competition, rapidly changing markets, and greater consumer awareness have altered the way in which corporations do business. To become more efficient, many industries have sought to model some operational aspects by gigantic optimization problems. It is not atypical to encounter models that capture 10(6) separate "yes" or "no" decisions to be made. Although one could, in prin...

Abstract. Time-varying network optimization problems have tradition-ally been solved by specialized algorithms. These algorithms have NP-complement time complexity. This paper considers the time-varying short-est path problem, in which can be optimally solved in O(T(m + n)) time,where T is a given integer. For this problem with arbitrary waiting times,we propose an approximation algorithm, whic...

In this paper, author proves the algorithms for the existence as well as the approximation of solutions to a couple of periodic boundary value problems of nonlinear first order ordinary integro-differential equations using operator theoretic techniques in a partially ordered metric space. The main results rely on the Dhage iteration method embodied in the recent hybrid fixed point theorems of D...