We analyse the herding phenomenon in the management style of Spanish equity funds. Using the methodology of Lakonishok et al. (1992) and Sharpe's style analysis (1992), we find interesting conclusions in the investment behaviour of fund managers, a barely-explored aspect, especially in the...

In this paper, we investigate the use of DC (Difference of Convex functions) models and algorithms in the application of trust-region methods to the solution of a class of nonlinear optimization problems where the constrained set is closed and convex (and, from a practical point of view, where...

A stochastic model is proposed to take into account the effect of a weak external field associated to diffusion, a discrete Master Equation is written down for the spatial distribution of particles. Approximate solutions are found for the first two cumulants, and applied to an example of...

The catalytic reduction of nitric oxide by hydrogen over a Pt surface is studied using a dynamic Monte Carlo (MC) method on a square lattice under low pressure conditions. Using a Langmuir–Hinshelwood reaction mechanism, a simplified model with only four adsorbed species (NO, H, O, and N) is...

We present a stochastic study of a polymerization reaction model. Using the WKB approximation and the method of factorial cumulants it is shown that the relaxation time of the second factorial cumulant is half the macroscopic relaxation time. Furthermore the system exhibits a globally...

This research analyses the determinants of demand for medical services in urban areas of Bolivia. It also examines the possible trade-offs between cost recovery and the use of health services for different age, sex, ethic, and income groups. The data are from the third year of the Encuesta...

Models which estimate influenza mortality probably overestimate this mortality because their baseline estimates include only nonepidemic weeks. We present a stochastic frontier estimation model which better reflects influenza mortality.