An empirical investigation of algorithms for the convex hull problems.

The objective of this thesis is to implement and empirically evaluate the perfor­mance of serial and parallel algorithms for the multidimensional convex hull problem. In recent years several new serial algorithms and parallel variants thereof have been developed. However, the algorithms were implemented on machines having very dif­ferent architectures with speeds differing by orders of magnitude. As a result, no comparison of the implementations can be done. Inefficiencies, ranging from major to minor in scope, are also inherent in each of these previous implementations. In this study we designed and implemented improved versions of existing serial algorithms for the multidimensional convex hull problem, designed and implemented improved parallel versions of these algorithms, and performed extensive computa­tional testing to determine the relative merits of each. All of the algorithms are based on mathematical programming formulations - those in which an objective and a set of limitations, or constraints, are stated in the form of mathematical functions. The computational results, obtained on a shared-memory multiprocessor, show that the algorithms vary in performance depending on certain characteristics of the problem data. However, one of the implementations was clearly superior to the others in all cases

Evaluating the productive efficiency and performance of U.S. commercial banks

This paper reviews various approaches to the measurement of core inflation that have been proposed in recent years. The objective is to determine whether the European Central Bank (ECB) should pay special attention to one or other of these measures in assessing inflation developments in the euro area. I put particular emphasis on the conceptual and practical problems that arise in the measurement of core inflation, and propose some criteria that could be used by the ECB to choose a core inflation measure.Banks and banking