BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250807T155203EDT-1330Zug1nl@132.216.98.100 DTSTAMP:20250807T195203Z DESCRIPTION:Title: Feature Selection for Linear Fixed Effects Models\n\n\n A bstract:\n\nLinear mixed-effects (LME) models are used to analyze nested o r combined data across a range of groups or clusters. These models use cov ariates to separate the total population variability (the fixed effects) f rom the group variability (the random effects). LMEs borrow strength acros s groups to estimate key statistics in cases where the data within groups may be sparse or highly variable\, and play a fundamental role in populati on health sciences\, meta-analysis\, life sciences\, and in many others do mains. In this talk we formally introduce a mathematical description of th e LME model and its feature selection variant. A naive proximal gradient d escent (PGD) algorithm for its solution is described and its deficiencies are explained. A novel solution strategy is proposed that is based on rela xation strategy that decouples the smooth from the nonsmooth components of the maximum likelihood objective. An optimal value function is obtained b y partially optimizing the smooth component of the decoupled problem. We s how that the resulting optimal value function has a locally Lipschitz grad ient and so a PGD algorithm can be applied to a feature selecting regulari zation of the optimal value function. At first this approach seems counter intuitive since the optimal value function adds yet another layer of comp lexity to the problem. However\, this complexity is mitigated by the use o f modern variational and numerical techniques. The resulting PGD algorithm applied to this reformulation is more stable and can rapidly identify the important features to high accuracy. The algorithmic details and the nume rical results are presented.\n DTSTART:20231113T210000Z DTEND:20231113T220000Z LOCATION:Room 1104\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:James V. Burke (University of Washington ) URL:/mathstat/channels/event/james-v-burke-university- washington-352634 END:VEVENT END:VCALENDAR