BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250811T052224EDT-5981eGixcg@132.216.98.100 DTSTAMP:20250811T092224Z DESCRIPTION:Title: Normalization effects on deep neural networks and deep l earning for scientific problems.\n\nAbstract:\n\nWe study the effect of no rmalization on the layers of deep neural networks. A given layer ii with N iNi hidden units is normalized by 1/Nγii1/Niγi with γi∈[1/2\,1]γi∈[1/2\,1] . We study the effect of the choice of the γiγi on the statistical behavio r of the neural network’s output (such as variance) as well as on the test accuracy and generalization properties of the architecture. We find that in terms of variance of the neural network’s output and test accuracy the best choice is to choose the γiγi’s to be equal to one\, which is the mean -field scaling. We also find that this is particularly true for the outer layer\, in that the neural network’s behavior is more sensitive in the sca ling of the outer layer as opposed to the scaling of the inner layers. The mechanism for the mathematical analysis is an asymptotic expansion for th e neural network’s output. An important practical consequence of the analy sis is that it provides a systematic and mathematically informed way to ch oose the learning rate hyperparameters. Such a choice guarantees that the neural network behaves in a statistically robust way as the number of hidd en units NiNi grow. Time permitting\, I will discuss applications of these ideas to design of deep learning algorithms for scientific problems inclu ding solving high dimensional partial differential equations (PDEs)\, clos ure of PDE models and reinforcement learning with applications to financia l engineering\, turbulence and more.\n\nSpeaker\n\nKonstantinos Spiliopoul os is the Director of Statistics and a Professor of Mathematics and Statis tics at Boston University (BU). He is a member of the Hariri Institute for Computing and of the Center for Information and Systems Engineering at BU . Between 2009-2012\, he was a Prager Assistant Professor at the Division of Applied Mathematics at Brown University\, and he earned his PhD in Math ematical Statistics at University of Maryland in 2009. He has been at BU s ince 2012. Currently\, Professor Spiliopoulos works on mathematical and co mputational methods for machine learning algorithms\, stochastic online al gorithms and deep learning for scientific problems\, accelerated Monte Car lo methods for sampling and optimization\, agent-based modeling and applic ations to financial engineering\, biological systems and opinion and socia l dynamics. He has received the Stochastics and Dynamics Best Paper Award in 2023\, the Simons Fellow in Mathematics Award in 2020\, the NSF Career Award in 2016\, the Hariri Institute Junior Fellowship Award in 2013\, the Seymour Goldberg Paper Award in 2008 and the Eygenidio Foundation Award i n 2004. His work has been continuously funded by NSF\, Simons Foundations and the DoD. He has co-authored the book “Mathematical Foundations of Deep Learning” to appear later in 2025.\n\nhttps://mcgill.zoom.us/j/8110065421 2\n\nMeeting ID: 811 0065 4212\n\nPasscode: None\n\n \n DTSTART:20250404T193000Z DTEND:20250404T203000Z LOCATION:Room 1104\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:Konstantinos Spiliopoulos (Boston University) URL:/mathstat/channels/event/konstantinos-spiliopoulos -boston-university END:VEVENT END:VCALENDAR