SORT : Statistics and Operations Research Transactions
SORT (ISSN 1696-2281 / ISSN electrònic 2013-8830) is an international biannual publication jointly published by Idescat and fours catalan universities (Universitat Politècnica de Catalunya, Universitat de Barcelona, Universitat Autònoma de Barcelona i Universitat de Girona) and with the collaboration of Regió Espanyola de la Societat Internacional de Biometria. Fully published in English (with abstracts in Catalan) promotes the publication of original articles on statistical methodology and applied statistics, operations research, official statistics and biometrics, as well as reviews of books and other publications in this field. SORT is published since 2003 and represents the third part of Qüestió (Quaderns d'Estadística i Investigació Operativa), published by Idescat since 1992.
Latest additions:
2015-12-23
08:06

28 p, 230.5 KB
Multinomial logistic estimation in dual frame surveys / Molina, David (Universidad de Granada. Departamento de Estadística) ; Rueda, Maria del Mar (Universidad de Granada. Departamento de Estadística) ; Arcos, Antonio (Universidad de Granada. Departamento de Estadística) ; Ranalli, Maria Giovanna (Università di Perugia. Department of Political Sciences)
We consider estimation techniques from dual frame surveys in the case of estimation of proportions when the variable of interest has multinomial outcomes. We propose to describe the joint distribution of the class indicators by a multinomial logistic model. [...]
2015
SORT : statistics and operations research transactions, Vol. 39 Núm. 2 (July-December 2015) , p. 309-336 (Articles)  ;
 Accés restringit a la UAB
2015-12-23
08:06

28 p, 328.9 KB
Parameter estimation of Poisson generalized linear mixed models based on three different statistical principles : a simulation study / Casals, Martí (Universitat de Barcelona) ; Langohr, Klaus (Universitat Politècnica de Catalunya. Departament d'Estadística i Investigació Operativa) ; Carrasco, Josep Lluís (Universitat de Barcelona) ; Rönnegård, Lars (Dalarna University (Falun, Suècia). Statistics Unit)
Generalized linear mixed models are flexible tools for modeling non-normal data and are usefulfor accommodating overdispersion in Poisson regression models with random effects. Theirmain difficulty resides in the parameter estimation because there is no analytic solution for themaximization of the marginal likelihood. [...]
2015
SORT : statistics and operations research transactions, Vol. 39 Núm. 2 (July-December 2015) , p. 281-308 (Articles)  ;
 Accés restringit a la UAB
2015-12-23
08:06

8 p, 83.4 KB
A note on "Double bounded Kumaraswamy-power series class of distributions" / Pogány, Tibor K. (University of Rijeka (Rijeka, Croàcia). Faculty of Maritime Studies) ; Nadarajah, Saralees (University of Manchester. School of Mathematics)
In a recent edition of SORT, Bidram and Nekoukhou proposed a novel class of distributions and derived its mathematical properties. Several of the mathematical properties are expressed as single infinite sums or double infinite sums. [...]
2015
SORT : statistics and operations research transactions, Vol. 39 Núm. 2 (July-December 2015) , p. 273-280 (Articles)  ;
 Accés restringit a la UAB
2015-12-23
08:06

20 p, 762.3 KB
Robust project management with the tilted beta distribution / Hahn, Eugene D. (Salisbury University. Department of Information and Decision Sciences) ; López Martín, María del Mar (Universidad de Granada. Departamento de Didáctica de la Matemática)
Recent years have seen an increase in the development of robust approaches for stochastic project management methodologies such as PERT (Program Evaluation and Review Technique). These robust approaches allow for elevated likelihoods of outlying events, thereby widening interval estimates of project completion times. [...]
2015
SORT : statistics and operations research transactions, Vol. 39 Núm. 2 (July-December 2015) , p. 253-272 (Articles)  ;
 Accés restringit a la UAB
2015-12-23
08:06

22 p, 485.8 KB
On the interpretation of differences between groups for compositional data / Martín-Fernández, Josep-Antoni (Universitat de Girona. Departament d’Informàtica i Matemàtica Aplicada) ; Daunis-i-Estadella, Josep (Universitat de Girona. Departament d’Informàtica i Matemàtica Aplicada) ; Mateu-Figueras, Glòria (Universitat de Girona. Departament d’Informàtica i Matemàtica Aplicada)
Social polices are designed using information collected in surveys; such as the Catalan TimeUse survey. Accurate comparisons of time use data among population groups are commonlyanalysed using statistical methods. [...]
2015
SORT : statistics and operations research transactions, Vol. 39 Núm. 2 (July-December 2015) , p. 231-252 (Articles)  ;
 Accés restringit a la UAB
2015-12-23
08:06

22 p, 209.2 KB
On the bivariate Sarmanov distribution and copula. An application on insurance data using truncated marginal distributi / Bahraoui, Zuhair (Universitat de Barcelona. Departament d'Econometria) ; Bolancé, Catalina (Universitat de Barcelona. Departament d'Econometria) ; Pelican, Elena (Ovidius University of Constanta (Constanta, Romania). Faculty of Mathematics and Computer Science) ; Vernic, Raluca (Ovidius University of Constanta (Constanta, Romania). Faculty of Mathematics and Computer Science)
The Sarmanov family of distributions can provide a good model for bivariate random variables and it is used to model dependency in a multivariate setting with given marginals. In this paper, we focus our attention on the bivariate Sarmanov distribution and copula with different truncated extreme value marginal distributions. [...]
2015
SORT : statistics and operations research transactions, Vol. 39 Núm. 2 (July-December 2015) , p. 209-230 (Articles)  ;
 Accés restringit a la UAB
2015-12-23
08:06

22 p, 237.6 KB
Likelihood-based inference for the power regression model / Martínez-Flórez, Guillermo (Universidad de Córdoba. Departamento de Matemáticas y Estadística) ; Bolfarine, Heleno (Universidade de São Paulo. Departamento de Estadística) ; Gómez, Héctor W. (Universidad de Antofagasta (Antofagasta, Xile). Departamento de Matemáticas)
In this paper we investigate an extension of the power-normal model, called the alpha-power model and specialize it to linear and nonlinear regression models, with and without correlated errors. Maximum likelihood estimation is considered with explicit derivation of the observed and expected Fisher information matrices. [...]
2015
SORT : statistics and operations research transactions, Vol. 39 Núm. 2 (July-December 2015) , p. 187-208 (Articles)  ;
 Accés restringit a la UAB
2015-12-23
08:06

38 p, 529.0 KB
Twenty years of P-splines / Eilers, Paul H.C. (Erasmus MC Universitair Medisch Centrum Rotterdam) ; Marx, Brian D. (Louisiana State University. Department of Experimental Statistics) ; Durbán, Maria (Universidad Carlos III de Madrid. Departamento de Estadística)
P-splines first appeared in the limelight twenty years ago. Since then they have become popular in applications and in theoretical work. The combination of a rich B-spline basis and a simple difference penalty lends itself well to a variety of generalizations, because it is based on regression. [...]
2015
SORT : statistics and operations research transactions, Vol. 39 Núm. 2 (July-December 2015) , p. 149-186 (Invited articles)  ;
 Accés restringit a la UAB
2015-06-25
08:06

20 p, 189.7 KB
The exponentiated discrete Weibull distribution / Nekoukhou, Vahid (University of Isfahan. Department of Statistics) ; Bidram, Hamid (University of Isfahan. Department of Statistics)
In this paper, the exponentiated discrete Weibull distribution is introduced. This new generalization of the discrete Weibull distribution can also be considered as a discrete analogue of the exponentiated Weibull distribution. [...]
2015
SORT : statistics and operations research transactions, Vol. 39 Núm. 1 (January-June 2015) , p. 127-146 (Articles)  ;
 Accés restringit a la UAB
2015-06-25
08:06

18 p, 242.3 KB
A comparison of computational approaches for maximum likelihood estimation of the Dirichlet parameters on high-dimensional data / Giordan, Marco (Istituto Agrario San Michele all'Adige (IASMA) Research and Innovation Centre) ; Wehrens, Ron (Istituto Agrario San Michele all'Adige (IASMA) Research and Innovation Centre)
Likelihood estimates of the Dirichlet distribution parameters can be obtained only through numerical algorithms. Such algorithms can provide estimates outside the correct range for the parameters and/or can require a large amount of iterations to reach convergence. [...]
2015
SORT : statistics and operations research transactions, Vol. 39 Núm. 1 (January-June 2015) , p. 109-126 (Articles)  ;
 Accés restringit a la UAB