eprintid: 1640 rev_number: 7 eprint_status: archive userid: 6 dir: disk0/00/00/16/40 datestamp: 2013-07-10 10:42:01 lastmod: 2013-07-10 10:42:01 status_changed: 2013-07-10 10:42:01 type: article metadata_visibility: show creators_name: Giovanis, Eleftherios creators_id: eleftherios.giovanis@imtlucca.it title: Ordinary Least Squares and Genetic Algorithms Optimization in Smoothing Transition Autoregressive (STAR) Models ispublished: pub subjects: HA subjects: HB divisions: EIC full_text_status: none keywords: Genetic Algorithms; MATLAB; Membership Functions; Smoothing Transition Autoregressive abstract: Abstract—In this paper we present, propose and examine additional membership functions as also we propose least squares with genetic algorithms optimization in order to find the optimum fuzzy membership functions parameters. More specifically, we present the tangent hyperbolic, Gaussian and Generalized bell functions. The reason we propose that is because Smoothing Transition Autoregressive (STAR) models follow fuzzy logic approach therefore more functions should be tested. Some numerical applications for S&P 500, FTSE 100 stock returns and for unemployment rate are presented and MATLAB routines are provided date: 2011-03 date_type: published publication: International Journal of Computer Information Systems volume: 2 number: 3 publisher: Silicon Valley Publishers pagerange: 17-23 refereed: TRUE issn: 2229-5208 official_url: http://www.svpublishers.co.uk/#/ijcis-mar-2011/4550826231 citation: Giovanis, Eleftherios Ordinary Least Squares and Genetic Algorithms Optimization in Smoothing Transition Autoregressive (STAR) Models. International Journal of Computer Information Systems, 2 (3). pp. 17-23. ISSN 2229-5208 (2011)