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:
2015-01-14
17:17

20 p, 151.8 KB
Global hypothesis test to compare the likelihood ratios of multiple binary diagnostic tests with ignorable missing data / Marín Jimenez, Ana Eugenia (Universidad de Granada) ; Roldán Nofuentes, José Antonio (Universidad de Granada)
In this article, a global hypothesis test is studied to simultaneously compare the likelihood ratios of multiple binary diagnostic tests when in the presence of partial disease verification the missing data mechanism is ignorable. [...]
2014
SORT : statistics and operations research transactions, Vol. 38 Núm. 2 (July-December 2014) , p. 305-324  ;
 Accés restringit a la UAB
2015-01-14
17:11

18 p, 349.5 KB
Untangling the influence of several contextual variables on the respondents' lexical choices : a statistical approach / Bécue-Bertaut, Mónica (Universitat Politècnica de Catalunya) ; Pagès, Jérôme (Agrocampus-Ouest (Rennes, França)) ; Kostov, Belchin (Institut d'Investigacions Biomèdiques August Pi i Sunyer)
This work proposes an original textual statistical method to uncover the relationships between opinions, expressed as free-text answers, and respondents’ characteristics. This method also identifies the specific links between each characteristic and certain words used in these answers. [...]
2014
SORT : statistics and operations research transactions, Vol. 38 Núm. 2 (July-December 2014) , p. 285-302  ;
 Accés restringit a la UAB
2015-01-14
17:01

14 p, 749.7 KB
Balancing properties : a need for the application of propensity score methods in estimation of treatment effects / Urkaregi, Arantza (Universidad del País Vasco (UPV/EHU)) ; Martínez Indart, Lorea (BioCruces Health Research Institute) ; Pijoán, José Ignacio (Instituto de Salud Carlos III (Madrid))
There has been recently a striking increase in the use of propensity score methods in health sciences research as a tool to adjust for selection bias in making causal inferences from observational controlled studies. [...]
2014
SORT : statistics and operations research transactions, Vol. 38 Núm. 2 (July-December 2014) , p. 271-284  ;
 Accés restringit a la UAB
2015-01-14
16:52

20 p, 200.6 KB
Exact prediction intervals for future current records and record range from any continuous distribution / Barakat, H. M. (Zagazig University (Zagazig, Egipte). Department of Mathematics) ; Nigm, E. M. (Zagazig University (Zagazig, Egipte). Department of Mathematics) ; Aldallal, R. A. (MSA University (El Caire, Egipte). Department of Mathematics and Statistics)
In this paper, a general method for predicting future lower and upper current records and record range from any arbitrary continuous distribution is proposed. Two pivotal statistics with the same explicit distribution for lower and upper current records are developed to construct prediction intervals for future current records. [...]
2014
SORT : statistics and operations research transactions, Vol. 38 Núm. 2 (July-December 2014) , p. 251-270  ;
 Accés restringit a la UAB
2015-01-14
16:43

20 p, 3.7 MB
New approaches in the chemometric analysis of infrared spectra of extra-virgin olive oils / Sánchez Rodríguez, María Isabel (Universidad de Córdoba. Departamento de Estadística, Econometría) ; Sánchez López, Elena M. (Universidad de Córdoba. Departamento de Química Orgánica) ; Marinas, Alberto (Universidad de Córdoba. Departamento de Química Orgánica) ; Caridad, José Mª (Universidad de Córdoba. Departamento de Estadística, Econometría) ; Urbano, Francisco José (Universidad de Córdoba. Departamento de Química Orgánica) ; Marinas, Jose Mª (Universidad de Córdoba. Departamento de Química Orgánica)
The aim of this paper is to apply new chemometric approaches to obtain quantitative information from near and mid infrared spectra of Andalusian extra-virgin olive oils, using gas chromatography as a classical reference analytical technique. [...]
2014
SORT : statistics and operations research transactions, Vol. 38 Núm. 2 (July-December 2014) , p. 231-250  ;
 Accés restringit a la UAB
2015-01-14
16:34

16 p, 162.7 KB
An extension of the slash-elliptical distribution / Rojas, Mario A. (Universidad de Antofagasta (Antofagasta, Xile). Departamento de Matematicas) ; Bolfarine, Heleno (Universidad de Sao Paulo. Departamento de Estatística) ; Gómez, Héctor W. (Universidad de Antofagasta (Antofagasta, Xile). Departamento de Matematicas)
This paper introduces an extension of the slash-elliptical distribution. This new distribution is generated as the quotient between two independent random variables, one from the elliptical family (numerator) and the other (denominator) a beta distribution. [...]
2014
SORT : statistics and operations research transactions, Vol. 38 Núm. 2 (July-December 2014) , p. 215-230  ;
 Accés restringit a la UAB
2015-01-14
16:19

34 p, 302.0 KB
Integrating network design and frequency setting in public transportation networks : a survey / López Ramos, Francisco (Pontificia Universidad Catolica de Valparaíso (Valparaíso, Xile))
This work reviews the literature on models which integrate the network design and the frequency setting phases in public transportation networks. These two phases determine to a large extent the service for the passengers and the operational costs for the operator of the system. [...]
2014
SORT : statistics and operations research transactions, Vol. 38 Núm. 2 (July-December 2014) , p. 181-214  ;
 Accés restringit a la UAB
2015-01-14
16:13

20 p, 153.7 KB
Estimators for the parameter mean of Morgenstern type bivariate generalized exponential distribution using ranked set sampling / Tahmasebi, Saeid (Persian Gulf University (Bushehr, Iran). Department of Statistics) ; Akbar Jafari, Ali (Yazd University (Yazd, Iran). Department of Statistics)
In situations where the sampling units in a study can be more easily ranked based on the measurement of an auxiliary variable, ranked set sampling provides unbiased estimators for the mean of a population that are more efficient than unbiased estimators based on simple random sampling. [...]
2014
SORT : statistics and operations research transactions, Vol. 38 Núm. 2 (July-December 2014) , p. 161-180  ;
 Accés restringit a la UAB
2015-01-14
15:31

22 p, 366.9 KB
Assessing the impact of early detection biases on breast cancer survival of Catalan women / Roso Llorach, Albert (Institut Universitari d’Investigacio en Atenció Primària Jordi Gol. Unitat de Suport a la Recerca Terres de l’Ebre) ; Forné, Carles (Universitat de Lleida. Departament de Ciencies Mèdiques Bàsiques) ; Macià, Francesc (Hospital del Mar. Servei d’Epidemiologia i Avaluacio) ; Galceran, Jaume (Fundació Lliga per a la Investigació i Prevenció del Càncer (Reus, Catalunya)) ; Marcos Gragera, Rafael (Unitat d’Epidemiologia i Registre de Cancer de Girona) ; Rué, Montserrat (Universitat de Lleida)
Survival estimates for women with screen-detected breast cancer are affected by biases specific to early detection. Lead-time bias occurs due to the advance of diagnosis, and length-sampling bias because tumors detected on screening exams are more likely to have slower growth than tumors symptomatically detected. [...]
2014
SORT : statistics and operations research transactions, Vol. 38 Núm. 2 (July-December 2014) , p. 139-160  ;
 Accés restringit a la UAB
2015-01-14
14:05

32 p, 2.8 MB
Stochastic cash flows modelled by homogeneous and non-homogeneous discrete time backward semi-Markov reward processes / Gismondi, Fulvio (Guglielmo Marconi University) ; Janssen, Jacques (Universite Libre de Bruxelles. Solvay Business School) ; Manca, Raimondo (Sapienza Universita di Roma. Dipartimento di Metodi e Modelli per l'Economia, il Territorio e la Finanza) ; Volpe di Prignano, Ernesto (Sapienza Universita di Roma. Dipartimento di Metodi e Modelli per l'Economia, il Territorio e la Finanza)
The main aim of this paper is to give a systematization on the stochastic cash flows evolution. The tools that are used for this purpose are discrete time semi-Markov reward processes. The paper is directed not only to semi-Markov researchers but also to a wider public, presenting a full treatment of these tools both in homogeneous and non-homogeneous environment. [...]
2014
SORT : statistics and operations research transactions, Vol. 38 Núm. 2 (July-December 2014) , p. 107-138  ;
 Accés restringit a la UAB