{ "135020-21875964": { "datetime_modified":"20250415T150338", "datetime_start":"20250428T090000", "datetime_end":"20250428T110000", "has_end_time":1, "date_start":"2025-04-28", "date_end":"2025-04-28", "time_start":"09:00:00", "time_end":"11:00:00", "time_zone":"America\/Detroit", "event_title":"Mixture and Admixture Models: Estimation Rate, Model Selection, Interpretation, and Applications in Heterogeneous Data Analysis", "occurrence_title":"", "combined_title":"Mixture and Admixture Models: Estimation Rate, Model Selection, Interpretation, and Applications in Heterogeneous Data Analysis: Trong Dat Do", "event_subtitle":"Trong Dat Do", "event_type":"Lecture \/ Discussion", "event_type_id":"13", "description":"Mixture and admixture models are powerful tools in modern statistics, with successful applications across diverse fields. By increasing the number of populations in the models, they can approximate any distribution arbitrarily well, albeit at the cost of interpretability. This poses a non-trivial question in practice: How should we select the complexity of mixture and admixture models and interpret them? This dissertation aims to answer this question by studying their asymptotic theory and developing novel statistical methods to select and interpret models fit to heterogeneous data, especially in genomics and population genetics. The two main tools used throughout the dissertation are optimal transport distances and non-parametric statistical methods.\r\n\r\nFirstly, we provide an in-depth asymptotic analysis of finite mixture models and their variants. By developing novel notions of strong identifiability, we prove the convergence rate of mixing measures under optimal transport distances in mixture of regression models and deviating mixture models, which are widely used extensions of finite mixture models. The pointwise parameter estimation rate is shown to be optimal when the number of populations is known, but far slower when it is over-fitted. Indeed, when over-fitting, many redundant mixture components can compete to estimate a common true component, so their estimation rates cancel out. Motivated by this phenomenon, we develop a novel algorithm to combine mixture components, leading to a better parameter estimation rate from over-fitted mixing measures. The outcome of this algorithm is a hierarchical clustering tree of mixing measures, which visualizes the relative distance between mixture components and is useful for selecting models. Our method is illustrated on several simulated datasets and a single-cell RNA-seq dataset.\r\n\r\nNext, we study the theory and methods for admixture models. In context of topic modeling, by developing a general representation of Dirichlet moment tensors by diagonal tensors and vice versa using techniques in enumerative combinatorics, we connect Latent Dirichlet Allocation to the (simpler) mixture of product models, which paves the way to provide the topics\u2019 estimation rate in both settings where the true number of topics is known and unknown. Finally, the large-sample theory of admixture models in the context of population genetics is studied. We propose an asymptotic version of a regularity condition known as the \u201canchor condition\u201d, which allows us to establish the parameter estimation rate in the large sample size and high-dimensional regime. Motivated by the theory, a fast and accurate model selection method using parametric bootstraps is proposed. We illustrate our theory and methods using several datasets simulated by the admixture and coalescent models.", "occurrence_notes":null, "guid":"135020-21875964@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/135020", "building_id":"1000167", "building_name":"West Hall", "campus_maps_id":"163", "room":"438", "location_name":"West Hall", "has_livestream":0, "cost":"", "tags":["Dissertation"], "website":"", "sponsors":[ { "group_name":"Department of Statistics Dissertation Defenses", "group_id":"4045", "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":21875964 } , "129602-21864115": { "datetime_modified":"20250211T122734", "datetime_start":"20250428T090000", "datetime_end":"20250428T160000", "has_end_time":1, "date_start":"2025-04-28", "date_end":"2025-04-28", "time_start":"09:00:00", "time_end":"16:00:00", "time_zone":"America\/Detroit", "event_title":"Redefining the Crown", "occurrence_title":"", "combined_title":"Redefining the Crown: The Voices of Black Breast Cancer Survivors", "event_subtitle":"The Voices of Black Breast Cancer Survivors", "event_type":"Exhibition", "event_type_id":"7", "description":"In Winter 2025, the Lane Hall exhibit space will feature a portraiture series titled Redefining the Crown showcasing the powerful stories of six Black breast cancer survivors.\r\n\r\nBased on a photo essay by U-M Faculty Versha Pleasant (MD\/MPH) and Ava Purkiss (PhD) in Medicine at Michigan, this exhibition examines the cultural and personal significance of hair within Black communities, particularly through the lens of breast cancer treatment and recovery. The term \"crown\" is deeply symbolic in Black culture, signifying beauty, strength, and identity. The featured photo essay by photographer Tafari Stevenson-Howard captures the intimate journeys of Ann Chatman, Tanisha Kennedy, Felecia McDaniel, Shantell Elaine McCoy, Tamara Lynn Myles, and Veleria Banks.\r\n\r\nThrough their narratives and portraits, the exhibit examines how these women have navigated the profound impact of hair loss caused by chemotherapy, inviting the audience to witness their stories with radical empathy. It explores the cultural pride and personal identity intricately tied to their hair, and how these elements are redefined amidst their battles with breast cancer.\r\n\r\nThe exhibit will be on view from January 21, 2025 to August 8, 2025. This exhibition is presented with support from IRWG, the Department of Women's and Gender Studies, and Michigan Medicine. \r\n\r\nLocated on the first floor of Lane Hall (204 S. State Street), the Exhibit Space is free and open to the public, M-F, 9am-4pm.", "occurrence_notes":null, "guid":"129602-21864115@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/129602", "building_id":"1000183", "building_name":"Lane Hall", "campus_maps_id":"84", "room":"", "location_name":"Lane Hall", "has_livestream":0, "cost":"", "tags":["african american","institute for research on women and gender","Women's And Gender Studies","women","Art"], "website":"https:\/\/www.michiganmedicine.org\/medicine-michigan\/redefining-crown", "sponsors":[ { "group_name":"Institute for Research on Women and Gender", "group_id":"1031", "website":"http:\/\/irwg.umich.edu\/" }, { "group_name":"Michigan Medicine", "group_id":"1033", "website":"https:\/\/www.facebook.com\/MichiganMedicine\/" }, { "group_name":"Women's and Gender Studies Department", "group_id":"2809", "website":"http:\/\/www.lsa.umich.edu\/wgs" } ], "image_url":"https:\/\/events.umich.edu\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "styled_images":{ "event_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_thumb\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "event_large":"https:\/\/events.umich.edu\/media\/cache\/event_large\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "event_large_2x":"https:\/\/events.umich.edu\/media\/cache\/event_large_2x\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "event_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/event_large_lightbox\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "group_thumb":"https:\/\/events.umich.edu\/media\/cache\/group_thumb\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "group_thumb_square":"https:\/\/events.umich.edu\/media\/cache\/group_thumb_square\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "group_large":"https:\/\/events.umich.edu\/media\/cache\/group_large\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "group_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/group_large_lightbox\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "event_large_crop":"https:\/\/events.umich.edu\/media\/cache\/event_large_crop\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "event_list":"https:\/\/events.umich.edu\/media\/cache\/event_list\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "event_list_2x":"https:\/\/events.umich.edu\/media\/cache\/event_list_2x\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "event_grid":"https:\/\/events.umich.edu\/media\/cache\/event_grid\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "event_grid_2x":"https:\/\/events.umich.edu\/media\/cache\/event_grid_2x\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "event_feature_large":"https:\/\/events.umich.edu\/media\/cache\/event_feature_large\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg", "event_feature_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_feature_thumb\/media\/attachments\/2024\/12\/event_129602_original-1.jpeg" }, "occurrence_count":120, "first_occurrence":21864018 } , "129585-21863807": { "datetime_modified":"20241203T104657", "datetime_start":"20250428T090000", "datetime_end":"20250428T200000", "has_end_time":1, "date_start":"2025-04-28", "date_end":"2025-04-28", "time_start":"09:00:00", "time_end":"20:00:00", "time_zone":"America\/Detroit", "event_title":"The Bibliophile and the Library: Private-Press Books from the Collection of Bill Heidrich", "occurrence_title":"", "combined_title":"The Bibliophile and the Library: Private-Press Books from the Collection of Bill Heidrich", "event_subtitle":"", "event_type":"Exhibition", "event_type_id":"7", "description":"View beautifully illustrated books that stand as remarkable testaments to the work of twentieth-century small private presses, which, in contrast to the trend of mass commercialization, produced limited editions that celebrated the uniqueness of manual craftsmanship. Features such as exquisite typeface design, letterpress printing, handmade paper, traditional illustration techniques like woodcut and engraving, and the inclusion of original art by renowned artists highlight the presses' dedication to artistry and detail.\r\n\r\nThe display opens with an edition of \"The Works of Geoffrey Chaucer,\" published in 1896 by William Morris at his Kelmscott Press, a pivotal press that greatly influenced the development of the private press movement as a means of preserving and revitalizing the fine printing and art traditions of the past. Additionally, the exhibit includes some examples of artist\u2019s proofs, offering a glimpse into the intricate creative process behind these exceptional works.\r\n\r\nThese books are on loan from the collection of Bill Heidrich, a long-time supporter of the University of Michigan Library.", "occurrence_notes":null, "guid":"129585-21863807@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/129585", "building_id":"1000181", "building_name":"Hatcher Graduate Library", "campus_maps_id":"65", "room":"Hatcher Gallery Exhibit Room, 1st floor", "location_name":"Hatcher Graduate Library", "has_livestream":0, "cost":"", "tags":["Library","Free","Exhibition","Books"], "website":"https:\/\/www.lib.umich.edu\/events", "sponsors":[ { "group_name":"University Library", "group_id":"1186", "website":"https:\/\/www.facebook.com\/UMichLibrary\/" } ], "image_url":"https:\/\/events.umich.edu\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "styled_images":{ "event_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_thumb\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "event_large":"https:\/\/events.umich.edu\/media\/cache\/event_large\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "event_large_2x":"https:\/\/events.umich.edu\/media\/cache\/event_large_2x\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "event_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/event_large_lightbox\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "group_thumb":"https:\/\/events.umich.edu\/media\/cache\/group_thumb\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "group_thumb_square":"https:\/\/events.umich.edu\/media\/cache\/group_thumb_square\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "group_large":"https:\/\/events.umich.edu\/media\/cache\/group_large\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "group_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/group_large_lightbox\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "event_large_crop":"https:\/\/events.umich.edu\/media\/cache\/event_large_crop\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "event_list":"https:\/\/events.umich.edu\/media\/cache\/event_list\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "event_list_2x":"https:\/\/events.umich.edu\/media\/cache\/event_list_2x\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "event_grid":"https:\/\/events.umich.edu\/media\/cache\/event_grid\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "event_grid_2x":"https:\/\/events.umich.edu\/media\/cache\/event_grid_2x\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "event_feature_large":"https:\/\/events.umich.edu\/media\/cache\/event_feature_large\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg", "event_feature_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_feature_thumb\/media\/attachments\/2024\/12\/event_129585_original-1.jpeg" }, "occurrence_count":108, "first_occurrence":21863702 } , "127313-21858851": { "datetime_modified":"20250428T092012", "datetime_start":"20250428T100000", "datetime_end":"20250428T150000", "has_end_time":1, "date_start":"2025-04-28", "date_end":"2025-04-28", "time_start":"10:00:00", "time_end":"15:00:00", "time_zone":"America\/Detroit", "event_title":"Study Days | April Showers, May Flowers", "occurrence_title":"", "combined_title":"Study Days | April Showers, May Flowers", "event_subtitle":"", "event_type":"Workshop \/ Seminar", "event_type_id":"21", "description":"Hello College of Engineering Students!We are so excited to be bringing back our Study Days event series! This is a come-and-go casual shared working space like a library or office (you can work on homework, writing, research reading, anything!) for only engineering graduate students to build community. Join us on April 28th from 10 AM - 3 PM in the Lurie Engineering Center (LEC) ABC Rooms. We will be giving away first come first serve College of Engineering rubber ducks.Please come by and join us! RSVP is not necessary but is encouraged to give us an approximate number of folks to expect!With care,Jordan Peyton", "occurrence_notes":null, "guid":"127313-21858851@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/127313", "building_id":"", "building_name":"", "campus_maps_id":"", "room":"", "location_name":"Lurie Engineering Center | ABC Rooms", "has_livestream":0, "cost":"", "tags":["Sessions"], "website":"https:\/\/sessions.studentlife.umich.edu\/p\/track\/12619", "sponsors":[ { "group_name":"Sessions @ Michigan", "group_id":"4791", "website":"https:\/\/sessions.studentlife.umich.edu\/" } ], "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":21858851 } }