BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Drupal iCal API//EN X-WR-CALNAME:Events items teaser X-WR-TIMEZONE:America/Toronto BEGIN:VTIMEZONE TZID:America/Toronto X-LIC-LOCATION:America/Toronto BEGIN:DAYLIGHT TZNAME:EDT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 DTSTART:20240310T070000 END:DAYLIGHT BEGIN:STANDARD TZNAME:EST TZOFFSETFROM:-0400 TZOFFSETTO:-0500 DTSTART:20241103T060000 END:STANDARD END:VTIMEZONE BEGIN:VEVENT UID:6867cd941bcb1 DTSTART;TZID=America/Toronto:20241115T153000 SEQUENCE:0 TRANSP:TRANSPARENT DTEND;TZID=America/Toronto:20241115T163000 URL:/combinatorics-and-optimization/events/tutte-colloq uium-guoyin-li SUMMARY:Tutte colloquium-Guoyin Li CLASS:PUBLIC DESCRIPTION:Summary \n\nTITLE: Proximal methods for nonsmooth and nonconvex fractional\nprograms: when sparse optimization meets fractional programs\ n\nSPEAKER:\n Guoyin Li\n\nAFFILIATION:\n University of New South Wales \n \nLOCATION:\n MC 5501\n\nABSTRACT:Nonsmooth and nonconvex fractional progr ams are ubiquitous\nand also highly challenging. It includes the composite optimization\nproblems studied extensively lately\, and encompasses many important\nmodern optimization problems arising from diverse areas such as the\nrecent proposed scale invariant sparse signal reconstruction problem \nin signal processing\, the robust Sharpe ratio optimization problems in\ nfinance and the sparse generalized eigenvalue problem in\ndiscrimination analysis. \n\nIn this talk\, we will introduce extrapolated proximal metho ds for\nsolving nonsmooth and nonconvex fractional programs and analyse th eir\nconvergence behaviour. Interestingly\, we will show that the proposed \nalgorithm exhibits linear convergence for the scale invariant sparse\nsi gnal reconstruction model\,  and the sparse generalized eigenvalue\nprobl em with either cardinality regularization or sparsity\nconstraints. This i s achieved by identifying the explicit\ndesingularization function of the Kurdyka-_Ł_ ojasiewicz inequality\nfor the merit function of the fraction al optimization models. Finally\,\nif time permits\, we will present some preliminary encouraging\nnumerical results for the proposed methods for sp arse signal\nreconstruction and sparse Fisher discriminant analysis\n\nThe talk is based on joint work with R.I. Bo ̧t\, M. Dao\, T.K. Pong\nand P. Yu.\n\n \n\n \n DTSTAMP:20250704T124820Z END:VEVENT END:VCALENDAR