Browsing by Author "Alcobé López, Santiago"

Classification of local stellar populations: the improved MEMPHIS algorithm  Part II
Cubarsí Morera, Rafael; Alcobé López, Santiago (200907)
External research report
Open AccessDiscontinuities of the local velocity distribution which are associated with stellar populations are studied from the improved statistical method MEMPHIS (Maximum Entropy of the Mixture Probability from HIerarchical ... 
Disc and halo kinematic populations from HIPPARCOS and GenevaCopenhagen surveys of the solar neighbourhood
Cubarsí Morera, Rafael; Alcobé López, Santiago; Vidojevic, S.; Ninkovic, S. (201002)
Article
Open AccessDiscontinuities in the local velocity distribution associated with stellar populations are studied using the Maximum Entropy of the Mixture Probability from HIerarchical Segregation (MEMPHIS) improved statistical method, ... 
Mixture parameters of a trivariate normal superposition from sample cumulants: application to the local stellar velocity distribution
Cubarsí Morera, Rafael; Alcobé López, Santiago (Carles Casacuberta, Josep Maria Font, Santiago Zarzuela, 2000)
Conference report
Open AccessThe velocity distribution of nearby stars can be studied as a mixture of two main population components. In order to determine the mixing proportions and the population parameters a combined geometricstatistical method ... 
Noninformative filtering of the local stellar velocity distribution to obtain two nearlypure statistical populations
Cubarsí Morera, Rafael; Alcobé López, Santiago; CatalaPoch, M.A. (UNIVERSITAT MANCHESTER, 2000)
Conference lecture
Open AccessThe determination of stellar population constants from the statistics of a global sample is extremely sensitive to the noise introduced by a few nontypical stars. The local velocity distribution can be better determined ... 
Optimal seggregation of a twocomponent sample based on maximim population entropy: an application to astronomy
Alcobé López, Santiago; CatalaPoch, M.A.; Cubarsí Morera, Rafael (Birkhäuser Verlag, 2000)
Conference report
Open AccessDetermination of stellar population parameters from statistics of global samples is extremely sensitive to the noise introduced by few nontypical stars. In order to obtain a nearlypure twopopulation mixture a subsample ... 
Partition entropy and chisquared error: the improved MEMPHIS algorithm  Part I
Cubarsí Morera, Rafael; Alcobé López, Santiago (200907)
External research report
Open AccessThe entropy of the population partition is studied as a function of the sampling parameter, so that within a particular interval of its graph, the plateau region, it is possible to get a stable estimation of the mixture ... 
Programas del algoritmo de clasificacion de poblaciones normales trivariantes a partir de la entropia de mezcla
Cubarsí Morera, Rafael; Alcobé López, Santiago (200101)
External research report
Open AccessThe complete FORTRAN codified programs of the segregation algorithm described in Alcobé (2001) are described. The classification algorithm is applied to study the trivariate velocity distribution of stars from the star ... 
Three kinematical methods to identify local galactic structures
Cubarsí Morera, Rafael; Alcobé López, Santiago; Vidojevic, S.; Ninkovic, S. (201005)
Conference lecture
Open AccessMethod one: by combining a sampling parameter related to an isolating integral of the stellar motion, an optimisation of the mixture approach, and a maximisation of the partition entropy for the constituent populations ...