{ "116160-21845979": { "datetime_modified":"20240405T195341", "datetime_start":"20240419T143000", "datetime_end":"20240419T151500", "has_end_time":1, "date_start":"2024-04-19", "date_end":"2024-04-19", "time_start":"14:30:00", "time_end":"15:15:00", "time_zone":"America\/Detroit", "event_title":"Sky Tonight", "occurrence_title":"", "combined_title":"Sky Tonight", "event_subtitle":"", "event_type":"Presentation", "event_type_id":"16", "description":"A live presentation on what to find in the sky tonight and for the coming few weeks. This presentation includes how to find the cardinal directions on your own with the North Star, current and upcoming constellations, visible planets, a few deep sky objects depending on the season, and other interesting astronomical visualizations. If you want to be able to look up from your own backyard and know what to look for, this is the show for you. \r\n\r\nThe state-of-the-art Planetarium & Dome Theater at the U-M Museum of Natural History transports visitors beyond distant stars and back in time from the comfort of reclining seats. Tickets are $8 for adults, seniors, and children ages 3 & up. Babies without tickets may be required to sit on an adult's lap. Tickets are available the day of the show in the Museum Store. Schedule subject to change.", "occurrence_notes":null, "guid":"116160-21845979@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/116160", "building_id":"1005169", "building_name":"Museum of Natural History", "campus_maps_id":"646", "room":"", "location_name":"Museum of Natural History", "has_livestream":0, "cost":"Tickets are $8 for adults, seniors, and children ages 3 & up.", "tags":["Astronomy","Museum","natural history museum","Natural Sciences","Space"], "website":"", "sponsors":[ { "group_name":"Planetarium & Dome Theater at the Museum of Natural History", "group_id":"3825", "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":102, "first_occurrence":21836330 } , "114772-21833587": { "datetime_modified":"20240407T213055", "datetime_start":"20240419T150000", "datetime_end":"20240419T160000", "has_end_time":1, "date_start":"2024-04-19", "date_end":"2024-04-19", "time_start":"15:00:00", "time_end":"16:00:00", "time_zone":"America\/Detroit", "event_title":"AIM Seminar: Solving Large Linear Systems Without Constructing a Preconditioner", "occurrence_title":"", "combined_title":"AIM Seminar: Solving Large Linear Systems Without Constructing a Preconditioner: Micha\u0142 Derezi\u0144ski, EECS, University of Michigan", "event_subtitle":"Micha\u0142 Derezi\u0144ski, EECS, University of Michigan", "event_type":"Lecture \/ Discussion", "event_type_id":"13", "description":"Abstract: Solving systems of linear equations has numerous applications across many areas, from data science and machine learning, to scientific computing, engineering and more. When these systems are too large to solve directly, iterative refinement methods such as conjugate gradient have proven to be a powerful alternative. The computational cost of these methods can be significantly affected by a problem-dependent condition number, which is often addressed by combining the iterative solver with a preconditioner, i.e., an easy to invert approximation of the original system. However, constructing a good preconditioner can still be very expensive, which leads to an undesirable trade-off between the cost of preconditioning and the cost of solving the linear system.\r\n\r\nIn this talk, I will present new stochastic iterative methods for solving linear systems based on the so-called Sketch-and-Project paradigm, which can reduce the condition number of the system without having to precondition it. This approach is based on the following phenomenon: Whenever the spectral structure of a linear system is amenable to constructing a strong preconditioner via low-rank matrix approximation, we can design a Sketch-and-Project solver that will implicitly take advantage of this to find the solution faster. In particular, I will show how this leads to solving an n x n linear system with at most k large (outlying) singular values in ~O( n^2 + n k^2 ) arithmetic operations, which is faster than the ~O( n^2 k ) cost of constructing a good preconditioner for this system.\r\n\r\n\r\nContact: Robert Krasny", "occurrence_notes":null, "guid":"114772-21833587@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/114772", "building_id":"1000166", "building_name":"East Hall", "campus_maps_id":"53", "room":"1084", "location_name":"East Hall", "has_livestream":0, "cost":"", "tags":["Mathematics"], "website":"", "sponsors":[ { "group_name":"Applied Interdisciplinary Mathematics (AIM) Seminar - Department of Mathematics", "group_id":"4882", "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":21833587 } , "120864-21845491": { "datetime_modified":"20240328T181721", "datetime_start":"20240419T150000", "datetime_end":"20240419T160000", "has_end_time":1, "date_start":"2024-04-19", "date_end":"2024-04-19", "time_start":"15:00:00", "time_end":"16:00:00", "time_zone":"America\/Detroit", "event_title":"Andrew Choi & Ellen Hayashi, violin", "occurrence_title":"", "combined_title":"Andrew Choi & Ellen Hayashi, violin", "event_subtitle":"", "event_type":"Performance", "event_type_id":"15", "description":"Undergraduates Andrew Choi & Ellen Hayashi perform a recital on the violin.", "occurrence_notes":null, "guid":"120864-21845491@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/120864", "building_id":"1000440", "building_name":"Earl V. Moore Building", "campus_maps_id":"52", "room":"Hankinson Rehearsal Hall", "location_name":"Earl V. Moore Building", "has_livestream":0, "cost":"Free - no tickets required", "tags":["Free","Music","North Campus"], "website":"", "sponsors":[ { "group_name":"School of Music, Theatre & Dance (SMTD)", "group_id":"155", "website":"http:\/\/smtd.umich.edu\/events" } ], "image_url":"https:\/\/events.umich.edu\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "styled_images":{ "event_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_thumb\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "event_large":"https:\/\/events.umich.edu\/media\/cache\/event_large\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "event_large_2x":"https:\/\/events.umich.edu\/media\/cache\/event_large_2x\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "event_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/event_large_lightbox\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "group_thumb":"https:\/\/events.umich.edu\/media\/cache\/group_thumb\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "group_thumb_square":"https:\/\/events.umich.edu\/media\/cache\/group_thumb_square\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "group_large":"https:\/\/events.umich.edu\/media\/cache\/group_large\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "group_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/group_large_lightbox\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "event_large_crop":"https:\/\/events.umich.edu\/media\/cache\/event_large_crop\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "event_list":"https:\/\/events.umich.edu\/media\/cache\/event_list\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "event_list_2x":"https:\/\/events.umich.edu\/media\/cache\/event_list_2x\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "event_grid":"https:\/\/events.umich.edu\/media\/cache\/event_grid\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "event_grid_2x":"https:\/\/events.umich.edu\/media\/cache\/event_grid_2x\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "event_feature_large":"https:\/\/events.umich.edu\/media\/cache\/event_feature_large\/media\/attachments\/2024\/03\/event_120864_original-1.jpg", "event_feature_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_feature_thumb\/media\/attachments\/2024\/03\/event_120864_original-1.jpg" }, "occurrence_count":1, "first_occurrence":21845491 } }