{ "149581-21906722": { "datetime_modified":"20260803T153429", "datetime_start":"20260909T160000", "datetime_end":"20260909T170000", "has_end_time":1, "date_start":"2026-09-09", "date_end":"2026-09-09", "time_start":"16:00:00", "time_end":"17:00:00", "time_zone":"America\/Detroit", "event_title":"Stability, Approximation, and Robustness of Optimal Policies in POMDPs", "occurrence_title":"", "combined_title":"Stability, Approximation, and Robustness of Optimal Policies in POMDPs: Yunus Emre Demirci, UM", "event_subtitle":"Yunus Emre Demirci, UM", "event_type":"Workshop \/ Seminar", "event_type_id":"21", "description":"In this talk, I will focus on the stability, approximation, and robustness of optimal policies in partially observable Markov decision processes (POMDPs) under discounted and average cost criteria.\n\nI will begin with filter kernel perturbation under model change. I will establish how small perturbations in the transition or observation kernels lead to explicit, nonasymptotic bounds on both the filter kernel and the performance of the induced policies. A primary result demonstrates that an optimal policy computed under an incorrect model remains near optimal for the true model, with quantitatively bounded errors.\n\nBuilding on these stability concepts, I will then talk about the average cost setting and describe conditions under which the nonlinear filter exhibits a contraction property. Under these conditions, the vanishing discounted approach yields a solution to the average cost optimality equation, guaranteeing the existence of a stationary optimal policy. Furthermore, this provides explicit bounds that quantify the influence of initial prior distribution errors and model errors on long run performance.\n\nFinally, I will present results on implementable approximations. I will introduce refined error bounds for finite window controllers and conclude by discussing how Q learning can be utilized through either finite window or the quantization of the belief process to obtain near optimal policies for both discounted and average cost criteria.", "occurrence_notes":null, "guid":"149581-21906722@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/149581", "building_id":"1000166", "building_name":"East Hall", "campus_maps_id":"53", "room":"1360", "location_name":"East Hall", "has_livestream":0, "cost":"", "tags":["Mathematics"], "website":"", "sponsors":[ { "group_name":"Financial\/Actuarial Mathematics Seminar - Department of Mathematics", "group_id":"4890", "website":"" }, { "group_name":"Department of Mathematics", "group_id":"3791", "website":"" } ], "image_url":"", "styled_images":{ "event_thumb":"", "event_large":"", "event_large_2x":"", "event_large_lightbox":"", "group_thumb":"", "group_thumb_square":"", "group_large":"", "group_large_lightbox":"", "event_large_crop":"", "event_list":"", "event_list_2x":"", "event_grid":"", "event_grid_2x":"", "event_feature_large":"", "event_feature_thumb":"" }, "occurrence_count":1, "first_occurrence":21906722 } , "151640-21911885": { "datetime_modified":"20260906T010254", "datetime_start":"20260909T160000", "datetime_end":"20260909T170000", "has_end_time":1, "date_start":"2026-09-09", "date_end":"2026-09-09", "time_start":"16:00:00", "time_end":"17:00:00", "time_zone":"America\/Detroit", "event_title":"Student AIM Seminar: Planning Meeting", "occurrence_title":"", "combined_title":"Student AIM Seminar: Planning Meeting", "event_subtitle":"", "event_type":"Workshop \/ Seminar", "event_type_id":"21", "description":"Hope you had a wonderful summer break, and welcome to the new semester! The Student AIM Seminar will be holding a planning meeting on Wednesday, September 9 from 4-5 pm in East Hall 3088. We'd love to hear about your ideas about any social\/professional event ideas, research topics, or speakers that you'd like us to facilitate for this semester. We especially encourage first-year PhD students to attend.", "occurrence_notes":null, "guid":"151640-21911885@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/151640", "building_id":"1000166", "building_name":"East Hall", "campus_maps_id":"53", "room":"3088", "location_name":"East Hall", "has_livestream":0, "cost":"", "tags":["Applied Mathematics"], "website":"https:\/\/sites.google.com\/umich.edu\/umich-siamstudentchapter\/home?authuser=0", "sponsors":[ { "group_name":"Student AIM Seminar - Department of Mathematics", "group_id":"4902", "website":"" }, { "group_name":"Department of Mathematics", "group_id":"3791", "website":"" } ], "image_url":"https:\/\/events.umich.edu\/media\/attachments\/2026\/09\/event_151640_original-1.png", "styled_images":{ "event_thumb":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_thumb\/media\/attachments\/2026\/09\/event_151640_original-1.png", "event_large":"https:\/\/events.umich.edu\/media\/cache\/event_large\/media\/attachments\/2026\/09\/event_151640_original-1.png", "event_large_2x":"https:\/\/events.umich.edu\/media\/cache\/event_large_2x\/media\/attachments\/2026\/09\/event_151640_original-1.png", "event_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/event_large_lightbox\/media\/attachments\/2026\/09\/event_151640_original-1.png", "group_thumb":"https:\/\/events.umich.edu\/media\/cache\/resolve\/group_thumb\/media\/attachments\/2026\/09\/event_151640_original-1.png", "group_thumb_square":"https:\/\/events.umich.edu\/media\/cache\/resolve\/group_thumb_square\/media\/attachments\/2026\/09\/event_151640_original-1.png", "group_large":"https:\/\/events.umich.edu\/media\/cache\/resolve\/group_large\/media\/attachments\/2026\/09\/event_151640_original-1.png", "group_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/resolve\/group_large_lightbox\/media\/attachments\/2026\/09\/event_151640_original-1.png", "event_large_crop":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_large_crop\/media\/attachments\/2026\/09\/event_151640_original-1.png", "event_list":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_list\/media\/attachments\/2026\/09\/event_151640_original-1.png", "event_list_2x":"https:\/\/events.umich.edu\/media\/cache\/event_list_2x\/media\/attachments\/2026\/09\/event_151640_original-1.png", "event_grid":"https:\/\/events.umich.edu\/media\/cache\/event_grid\/media\/attachments\/2026\/09\/event_151640_original-1.png", "event_grid_2x":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_grid_2x\/media\/attachments\/2026\/09\/event_151640_original-1.png", "event_feature_large":"https:\/\/events.umich.edu\/media\/cache\/resolve\/event_feature_large\/media\/attachments\/2026\/09\/event_151640_original-1.png", "event_feature_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_feature_thumb\/media\/attachments\/2026\/09\/event_151640_original-1.png" }, "occurrence_count":1, "first_occurrence":21911885 } }