BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250712T093431EDT-0306Rvl6Zu@132.216.98.100 DTSTAMP:20250712T133431Z DESCRIPTION:Title: Heteroskedastic Sparse PCA in High Dimensions\n\n\n Abstr act:\n\n\nPrincipal component analysis (PCA) is one of the most commonly u sed techniques for dimension reduction and feature extraction. Though it h as been well-studied for high-dimensional sparse PCA\, little is known whe n the noise is heteroskedastic\, which turns out to be ubiquitous in many scenarios\, like biological sequencing data and information network data. We propose an iterative algorithm for sparse PCA in the presence of hetero skedastic noise\, which alternatively updates the estimates of the sparse eigenvectors using the power method with adaptive thresholding in one step \, and imputes the diagonal values of the sample covariance matrix to redu ce the estimation bias due to heteroskedasticity in the other step. Our pr ocedure is computationally fast and provably optimal under the generalized spiked covariance model\, assuming the leading eigenvectors are sparse. A comprehensive simulation study demonstrates its robustness and effectiven ess in various settings.\n\n\n Speaker\n\n\nDr. Zhao Ren is an Associate Pr ofessor of Statistics in Dietrich School of Arts and Sciences at the Unive rsity of Pittsburgh. His research focuses on high dimensional statistical inference\, graphical models and statistical machine learning\, nonparamet ric function estimation\, and applications in Statistical Genomics.\n\n\n \n \n Hybrid: In person / Zoom\n\n Location: Burnside Hall 1104\n\n https://mc gill.zoom.us/j/83436686293?pwd=b0RmWmlXRXE3OWR6NlNIcWF5d0dJQT09\n\n Meeting ID: 834 3668 6293\n\n Passcode: 12345\n \n \n\n DTSTART:20230310T203000Z DTEND:20230310T213000Z LOCATION:Room 1104\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:Zhao Ren (University of Pittsburgh) URL:/mathstat/channels/event/zhao-ren-university-pitts burgh-346582 END:VEVENT END:VCALENDAR