Geostationary satellites are an efficient way to provide a large scale multipoint communication service. In the context of reliable multicast communications, a new hybrid satellite/terrestrial approach is proposed. It aims at reducing the overall communication cost using satellite broadcasting only when enough receivers are present, and terrestrial transmissions otherwise. This approach has bee...

Zebu breeds of cattle from southern part of India are well known for their adaptability to extreme climatic conditions, draught efficiency, disease resistance and poor nutritional environment. Selection of appropriate populations for conservation of such genetic resources is needed in view of preventing rapid erosion of animal genetic resources. Estimation of genetic diversity is essential to d...

This paper presents a biased random-key genetic algorithm for solving a multi-objective optimization problem concerning the management of agile Earth observing satellites. It addresses the selection and scheduling of a subset of photographs from a set of candidates in order to optimize two objectives: maximizing the total profit, and ensuring fairness among users by minimizing the maximum profi...

Assume that a constellation of satellites is required to flight close to a given nominal trajectory and that there is some freedom in the selection of the geometry of the constellation. If we are interested in avoiding large variations of the mutual distances between the spacecraft, we can consider the possible existence of regions of zero relative radial acceleration with respect to the nomina...

At the present time, early-type brightest cluster galaxies in the SDSS MaxBCG and C4 catalogs have larger sizes than early-type galaxies of similar luminosity, whether these other objects are in the field, or are satellites in clusters. BCG sizes are also stronger functions of luminosity Re ∝ L than are the sizes of the bulk of the population; this remains true if one restricts attention to nar...