Mutual positions of the Galilean satellites of Jupiter from photometric observations during their mutual occultations and eclipses in 1997


We report the final results of the 1997 campaign of
photometric observations of the mutual phenomena of the Galilean
satellites carried out at observatories in Kazakhstan, Russia, and
Ukraine. Our results contribute substantially to the
world data bank of such observations
and will allow the model of the motion of Galilean 
satellites to be further refined. To facilitate the use of
photometric data, we reduced them by computing the planetocentric
rectangular
coordinate differences of satellite pairs for a number of instants
of time so we deduce the differences for one instant from one
observed light curve.
It is these reduced data that constitute the principal result of this work. We based our data reduction on the method which we developed in
earlier papers (Emel'yanov 1999; Emel'yanov 2000). The accuracy of observations was estimated in the process of reduction. The paper also describes the equipment used.

Optimizing radial basis functions by D.C. programming and its use in direct search for global derivative-free optimization

In this paper we address the global optimization of functions subject to bound and linear constraints without using derivatives of the objective function. We investigate the use of derivative-free models based on radial basis functions (RBFs) in the search step of direct-search methods of directional type. We also study the application of algorithms based on difference of convex (d.c.) functions programming to solve the resulting subproblems which consist of the minimization of the RBF models subject to simple bounds on the variables. Extensive numerical results are reported with a test set of bound and linearly constrained problems.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/MAT/64838/2006, PTDC/MAT/098214/200