[{"file_date_updated":"2022-04-07T08:11:51Z","date_updated":"2023-06-23T06:26:41Z","date_created":"2022-04-07T08:19:54Z","author":[{"last_name":"Matejovicova","first_name":"Lenka","id":"2DFDEC72-F248-11E8-B48F-1D18A9856A87","full_name":"Matejovicova, Lenka"}],"department":[{"_id":"GradSch"},{"_id":"NiBa"}],"publisher":"Institute of Science and Technology Austria","publication_status":"published","year":"2022","publication_identifier":{"isbn":["978-3-99078-016-9"],"issn":["2663-337X"]},"month":"04","language":[{"iso":"eng"}],"supervisor":[{"id":"4880FE40-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-8548-5240","first_name":"Nicholas H","last_name":"Barton","full_name":"Barton, Nicholas H"}],"acknowledged_ssus":[{"_id":"ScienComp"},{"_id":"Bio"}],"degree_awarded":"PhD","doi":"10.15479/at:ista:11128","tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png"},"oa":1,"abstract":[{"lang":"eng","text":"Although we often see studies focusing on simple or even discrete traits in studies of colouration,\r\nthe variation of “appearance” phenotypes found in nature is often more complex, continuous\r\nand high-dimensional. Therefore, we developed automated methods suitable for large datasets\r\nof genomes and images, striving to account for their complex nature, while minimising human\r\nbias. We used these methods on a dataset of more than 20, 000 plant SNP genomes and\r\ncorresponding fower images from a hybrid zone of two subspecies of Antirrhinum majus with\r\ndistinctly coloured fowers to improve our understanding of the genetic nature of the fower\r\ncolour in our study system.\r\nFirstly, we use the advantage of large numbers of genotyped plants to estimate the haplotypes in\r\nthe main fower colour regulating region. We study colour- and geography-related characteristics\r\nof the estimated haplotypes and how they connect to their relatedness. We show discrepancies\r\nfrom the expected fower colour distributions given the genotype and identify particular\r\nhaplotypes leading to unexpected phenotypes. We also confrm a signifcant defcit of the\r\ndouble recessive recombinant and quite surprisingly, we show that haplotypes of the most\r\nfrequent parental type are much less variable than others.\r\nSecondly, we introduce our pipeline capable of processing tens of thousands of full fower\r\nimages without human interaction and summarising each image into a set of informative scores.\r\nWe show the compatibility of these machine-measured fower colour scores with the previously\r\nused manual scores and study impact of external efect on the resulting scores. Finally, we use\r\nthe machine-measured fower colour scores to ft and examine a phenotype cline across the\r\nhybrid zone in Planoles using full fower images as opposed to discrete, manual scores and\r\ncompare it with the genotypic cline."}],"alternative_title":["ISTA Thesis"],"type":"dissertation","oa_version":"Published Version","file":[{"date_created":"2022-04-07T08:11:34Z","date_updated":"2022-04-07T08:11:34Z","checksum":"e9609bc4e8f8e20146fc1125fd4f1bf7","file_id":"11129","relation":"main_file","creator":"cchlebak","file_size":11906472,"content_type":"application/pdf","file_name":"LenkaPhD_Official_PDFA.pdf","access_level":"open_access"},{"file_name":"LenkaPhD Official_source.zip","access_level":"closed","creator":"cchlebak","content_type":"application/x-zip-compressed","file_size":23036766,"file_id":"11130","relation":"source_file","date_created":"2022-04-07T08:11:51Z","date_updated":"2022-04-07T08:11:51Z","checksum":"99d67040432fd07a225643a212ee8588"}],"ddc":["576","582"],"title":"Genetic basis of flower colour as a model for adaptive evolution","status":"public","_id":"11128","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","has_accepted_license":"1","article_processing_charge":"No","day":"06","date_published":"2022-04-06T00:00:00Z","page":"112","citation":{"ama":"Matejovicova L. Genetic basis of flower colour as a model for adaptive evolution. 2022. doi:10.15479/at:ista:11128","apa":"Matejovicova, L. (2022). Genetic basis of flower colour as a model for adaptive evolution. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:11128","ieee":"L. Matejovicova, “Genetic basis of flower colour as a model for adaptive evolution,” Institute of Science and Technology Austria, 2022.","ista":"Matejovicova L. 2022. Genetic basis of flower colour as a model for adaptive evolution. Institute of Science and Technology Austria.","short":"L. Matejovicova, Genetic Basis of Flower Colour as a Model for Adaptive Evolution, Institute of Science and Technology Austria, 2022.","mla":"Matejovicova, Lenka. Genetic Basis of Flower Colour as a Model for Adaptive Evolution. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:11128.","chicago":"Matejovicova, Lenka. “Genetic Basis of Flower Colour as a Model for Adaptive Evolution.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:11128."}},{"abstract":[{"lang":"eng","text":"G protein-coupled receptors (GPCRs) respond to specific ligands and regulate multiple processes ranging from cell growth and immune responses to neuronal signal transmission. However, ligands for many GPCRs remain unknown, suffer from off-target effects or have poor bioavailability. Additional challenges exist to dissect cell-type specific responses when the same GPCR is expressed on several cell types within the body. Here, we overcome these limitations by engineering DREADD-based GPCR chimeras that selectively bind their agonist clozapine-N-oxide (CNO) and mimic a GPCR-of-interest in a desired cell type.\r\nWe validated our approach with β2-adrenergic receptor (β2AR/ADRB2) and show that our chimeric DREADD-β2AR triggers comparable responses on second messenger and kinase activity, post-translational modifications, and protein-protein interactions. Since β2AR is also enriched in microglia, which can drive inflammation in the central nervous system, we expressed chimeric DREADD-β2AR in primary microglia and successfully recapitulate β2AR-mediated filopodia formation through CNO stimulation. To dissect the role of selected GPCRs during microglial inflammation, we additionally generated DREADD-based chimeras for microglia-enriched GPR65 and GPR109A/HCAR2. In a microglia cell line, DREADD-β2AR and DREADD-GPR65 both modulated the inflammatory response with a similar profile as endogenously expressed β2AR, while DREADD-GPR109A showed no impact.\r\nOur DREADD-based approach provides the means to obtain mechanistic and functional insights into GPCR signaling on a cell-type specific level."}],"alternative_title":["ISTA Thesis"],"type":"dissertation","file":[{"access_level":"open_access","file_name":"Thesis_Rouven_Schulz_2022_final.pdf","file_size":28079331,"content_type":"application/pdf","creator":"rschulz","relation":"main_file","file_id":"11970","checksum":"61b1b666a210ff7cdd0e95ea75207a13","success":1,"date_created":"2022-08-25T08:59:57Z","date_updated":"2022-08-25T08:59:57Z"},{"file_name":"Thesis_Rouven_Schulz_2022_final.docx","access_level":"closed","file_size":27226963,"content_type":"application/vnd.openxmlformats-officedocument.wordprocessingml.document","creator":"rschulz","relation":"source_file","file_id":"11971","date_updated":"2022-08-25T09:33:31Z","date_created":"2022-08-25T09:00:11Z","checksum":"2b8f95ea1c134dbdb927b41b1dbeeeb5"}],"oa_version":"Published Version","status":"public","title":"Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function","ddc":["570"],"_id":"11945","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","has_accepted_license":"1","article_processing_charge":"No","day":"23","date_published":"2022-08-23T00:00:00Z","page":"133","citation":{"short":"R. Schulz, Chimeric G Protein-Coupled Receptors Mimic Distinct Signaling Pathways and Modulate Microglia Function, Institute of Science and Technology Austria, 2022.","mla":"Schulz, Rouven. Chimeric G Protein-Coupled Receptors Mimic Distinct Signaling Pathways and Modulate Microglia Function. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:11945.","chicago":"Schulz, Rouven. “Chimeric G Protein-Coupled Receptors Mimic Distinct Signaling Pathways and Modulate Microglia Function.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:11945.","ama":"Schulz R. Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function. 2022. doi:10.15479/at:ista:11945","apa":"Schulz, R. (2022). Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:11945","ieee":"R. Schulz, “Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function,” Institute of Science and Technology Austria, 2022.","ista":"Schulz R. 2022. Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function. Institute of Science and Technology Austria."},"file_date_updated":"2022-08-25T09:33:31Z","date_updated":"2023-08-03T13:02:26Z","date_created":"2022-08-23T11:33:11Z","related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"11995"}]},"author":[{"full_name":"Schulz, Rouven","orcid":"0000-0001-5297-733X","id":"4C5E7B96-F248-11E8-B48F-1D18A9856A87","last_name":"Schulz","first_name":"Rouven"}],"publisher":"Institute of Science and Technology Austria","department":[{"_id":"GradSch"},{"_id":"SaSi"}],"publication_status":"published","year":"2022","publication_identifier":{"issn":["2663-337X"]},"month":"08","language":[{"iso":"eng"}],"acknowledged_ssus":[{"_id":"Bio"},{"_id":"PreCl"},{"_id":"LifeSc"}],"degree_awarded":"PhD","supervisor":[{"id":"36ACD32E-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0001-8635-0877","first_name":"Sandra","last_name":"Siegert","full_name":"Siegert, Sandra"}],"doi":"10.15479/at:ista:11945","project":[{"_id":"267F75D8-B435-11E9-9278-68D0E5697425","name":"Modulating microglia through G protein-coupled receptor (GPCR) signaling"}],"tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png"},"oa":1},{"type":"dissertation","alternative_title":["ISTA Thesis"],"abstract":[{"text":"The scope of this thesis is to study quantum systems exhibiting a continuous symmetry that\r\nis broken on the level of the corresponding effective theory. In particular we are going to\r\ninvestigate translation-invariant Bose gases in the mean field limit, effectively described by\r\nthe Hartree functional, and the Fröhlich Polaron in the regime of strong coupling, effectively\r\ndescribed by the Pekar functional. The latter is a model describing the interaction between a\r\ncharged particle and the optical modes of a polar crystal. Regarding the former, we assume in\r\naddition that the particles in the gas are unconfined, and typically we will consider particles\r\nthat are subject to an attractive interaction. In both cases the ground state energy of the\r\nHamiltonian is not a proper eigenvalue due to the underlying translation-invariance, while on\r\nthe contrary there exists a whole invariant orbit of minimizers for the corresponding effective\r\nfunctionals. Both, the absence of proper eigenstates and the broken symmetry of the effective\r\ntheory, make the study significantly more involved and it is the content of this thesis to\r\ndevelop a frameworks which allows for a systematic way to circumvent these issues.\r\nIt is a well-established result that the ground state energy of Bose gases in the mean field limit,\r\nas well as the ground state energy of the Fröhlich Polaron in the regime of strong coupling, is\r\nto leading order given by the minimal energy of the corresponding effective theory. As part\r\nof this thesis we identify the sub-leading term in the expansion of the ground state energy,\r\nwhich can be interpreted as the quantum correction to the classical energy, since the effective\r\ntheories under consideration can be seen as classical counterparts.\r\nWe are further going to establish an asymptotic expression for the energy-momentum relation\r\nof the Fröhlich Polaron in the strong coupling limit. In the regime of suitably small momenta,\r\nthis asymptotic expression agrees with the energy-momentum relation of a free particle having\r\nan effectively increased mass, and we find that this effectively increased mass agrees with the\r\nconjectured value in the physics literature.\r\nIn addition we will discuss two unrelated papers written by the author during his stay at ISTA\r\nin the appendix. The first one concerns the realization of anyons, which are quasi-particles\r\nacquiring a non-trivial phase under the exchange of two particles, as molecular impurities.\r\nThe second one provides a classification of those vector fields defined on a given manifold\r\nthat can be written as the gradient of a given functional with respect to a suitable metric,\r\nprovided that some mild smoothness assumptions hold. This classification is subsequently\r\nused to identify those quantum Markov semigroups that can be written as a gradient flow of\r\nthe relative entropy.\r\n","lang":"eng"}],"_id":"12390","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","status":"public","title":"Translation-invariant quantum systems with effectively broken symmetry","ddc":["500"],"oa_version":"Published Version","file":[{"creator":"cchlebak","content_type":"application/pdf","file_size":3095225,"file_name":"Brooks_Thesis.pdf","access_level":"open_access","date_updated":"2023-01-26T10:02:34Z","date_created":"2023-01-26T10:02:34Z","success":1,"checksum":"b31460e937f33b557abb40ebef02b567","file_id":"12391","relation":"main_file"},{"file_size":809842,"content_type":"application/octet-stream","creator":"cchlebak","access_level":"closed","file_name":"Brooks_Thesis.tex","checksum":"9751869fa5e7981588ad4228f4fd4bd6","date_created":"2023-01-26T10:02:42Z","date_updated":"2023-01-26T10:02:42Z","relation":"source_file","file_id":"12392"}],"day":"15","has_accepted_license":"1","article_processing_charge":"No","citation":{"chicago":"Brooks, Morris. “Translation-Invariant Quantum Systems with Effectively Broken Symmetry.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:12390.","mla":"Brooks, Morris. Translation-Invariant Quantum Systems with Effectively Broken Symmetry. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:12390.","short":"M. Brooks, Translation-Invariant Quantum Systems with Effectively Broken Symmetry, Institute of Science and Technology Austria, 2022.","ista":"Brooks M. 2022. Translation-invariant quantum systems with effectively broken symmetry. Institute of Science and Technology Austria.","apa":"Brooks, M. (2022). Translation-invariant quantum systems with effectively broken symmetry. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12390","ieee":"M. Brooks, “Translation-invariant quantum systems with effectively broken symmetry,” Institute of Science and Technology Austria, 2022.","ama":"Brooks M. Translation-invariant quantum systems with effectively broken symmetry. 2022. doi:10.15479/at:ista:12390"},"page":"196","date_published":"2022-12-15T00:00:00Z","file_date_updated":"2023-01-26T10:02:42Z","ec_funded":1,"year":"2022","publication_status":"published","publisher":"Institute of Science and Technology Austria","department":[{"_id":"GradSch"},{"_id":"RoSe"}],"author":[{"full_name":"Brooks, Morris","id":"B7ECF9FC-AA38-11E9-AC9A-0930E6697425","orcid":"0000-0002-6249-0928","first_name":"Morris","last_name":"Brooks"}],"related_material":{"record":[{"status":"public","relation":"part_of_dissertation","id":"9005"}]},"date_updated":"2023-08-07T13:32:09Z","date_created":"2023-01-26T10:00:42Z","month":"12","publication_identifier":{"issn":["2663-337X"]},"tmp":{"name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","image":"/images/cc_by_nc_sa.png","short":"CC BY-NC-SA (4.0)"},"oa":1,"project":[{"call_identifier":"H2020","name":"Analysis of quantum many-body systems","grant_number":"694227","_id":"25C6DC12-B435-11E9-9278-68D0E5697425"}],"doi":"10.15479/at:ista:12390","supervisor":[{"full_name":"Seiringer, Robert","last_name":"Seiringer","first_name":"Robert","orcid":"0000-0002-6781-0521","id":"4AFD0470-F248-11E8-B48F-1D18A9856A87"}],"degree_awarded":"PhD","language":[{"iso":"eng"}]},{"ec_funded":1,"file_date_updated":"2023-01-25T10:52:46Z","related_material":{"record":[{"id":"9350","relation":"part_of_dissertation","status":"public"}]},"author":[{"orcid":"0000-0001-5809-9566","id":"49DA7910-F248-11E8-B48F-1D18A9856A87","last_name":"Arslan","first_name":"Feyza N","full_name":"Arslan, Feyza N"}],"date_updated":"2023-08-08T13:14:10Z","date_created":"2023-01-25T10:43:24Z","year":"2022","publisher":"Institute of Science and Technology Austria","department":[{"_id":"GradSch"},{"_id":"CaHe"}],"publication_status":"published","publication_identifier":{"issn":["2663-337X"],"isbn":[" 978-3-99078-025-1 "]},"month":"09","doi":"10.15479/at:ista:12153","language":[{"iso":"eng"}],"acknowledged_ssus":[{"_id":"LifeSc"},{"_id":"Bio"},{"_id":"NanoFab"}],"degree_awarded":"PhD","supervisor":[{"full_name":"Heisenberg, Carl-Philipp J","first_name":"Carl-Philipp J","last_name":"Heisenberg","id":"39427864-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-0912-4566"}],"oa":1,"tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png"},"project":[{"call_identifier":"H2020","name":"Interaction and feedback between cell mechanics and fate specification in vertebrate gastrulation","grant_number":"742573","_id":"260F1432-B435-11E9-9278-68D0E5697425"}],"abstract":[{"lang":"eng","text":"Metazoan development relies on the formation and remodeling of cell-cell contacts. The \r\nbinding of adhesion receptors and remodeling of the actomyosin cell cortex at cell-cell \r\ninteraction sites have been implicated in cell-cell contact formation. Yet, how these two \r\nprocesses functionally interact to drive cell-cell contact expansion and strengthening \r\nremains unclear. Here, we study how primary germ layer progenitor cells from zebrafish \r\nbind to supported lipid bilayers (SLB) functionalized with E-cadherin ectodomains as an \r\nassay system for monitoring cell-cell contact formation at high spatiotemporal resolution. \r\nWe show that cell-cell contact formation represents a two-tiered process: E-cadherin\u0002mediated downregulation of the small GTPase RhoA at the forming contact leads to both \r\ndepletion of Myosin-2 and decrease of F-actin. This is followed by centrifugal actin \r\nnetwork flows at the contact triggered by a sharp gradient of Myosin-2 at the rim of the \r\ncontact zone, with Myosin-2 displaying higher cortical localization outside than inside of \r\nthe contact. These centrifugal cortical actin flows, in turn, not only further dilute the actin \r\nnetwork at the contact disc, but also lead to an accumulation of both F-actin and E\u0002cadherin at the contact rim. Eventually, this combination of actomyosin downregulation \r\nand flows at the contact contribute to the characteristic molecular organization implicated \r\nin contact formation and maintenance: depletion of cortical actomyosin at the contact disc, \r\ndriving contact expansion by lowering interfacial tension at the contact, and accumulation \r\nof both E-cadherin and F-actin at the contact rim, mechanically linking the contractile \r\ncortices of the adhering cells. Thus, using a biomimetic assay, we exemplify how \r\nadhesion signaling and cell mechanics function together to modulate the spatial \r\norganization of cell-cell contacts."}],"type":"dissertation","alternative_title":["ISTA Thesis"],"oa_version":"Published Version","file":[{"content_type":"application/pdf","file_size":14581024,"creator":"cchlebak","file_name":"THESIS_FINAL_FArslan_pdfa.pdf","access_level":"open_access","date_created":"2023-01-25T10:52:46Z","date_updated":"2023-01-25T10:52:46Z","checksum":"e54a3e69b83ebf166544164afd25608e","success":1,"relation":"main_file","file_id":"12369"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","_id":"12368","title":"Remodeling of E-cadherin-mediated contacts via cortical flows","ddc":["570"],"status":"public","article_processing_charge":"No","has_accepted_license":"1","day":"29","date_published":"2022-09-29T00:00:00Z","citation":{"chicago":"Arslan, Feyza N. “Remodeling of E-Cadherin-Mediated Contacts via Cortical Flows.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:12153.","mla":"Arslan, Feyza N. Remodeling of E-Cadherin-Mediated Contacts via Cortical Flows. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:12153.","short":"F.N. Arslan, Remodeling of E-Cadherin-Mediated Contacts via Cortical Flows, Institute of Science and Technology Austria, 2022.","ista":"Arslan FN. 2022. Remodeling of E-cadherin-mediated contacts via cortical flows. Institute of Science and Technology Austria.","ieee":"F. N. Arslan, “Remodeling of E-cadherin-mediated contacts via cortical flows,” Institute of Science and Technology Austria, 2022.","apa":"Arslan, F. N. (2022). Remodeling of E-cadherin-mediated contacts via cortical flows. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12153","ama":"Arslan FN. Remodeling of E-cadherin-mediated contacts via cortical flows. 2022. doi:10.15479/at:ista:12153"},"page":"113"},{"project":[{"name":"The Wittgenstein Prize","call_identifier":"FWF","_id":"25F42A32-B435-11E9-9278-68D0E5697425","grant_number":"Z211"},{"name":"Vigilant Algorithmic Monitoring of Software","call_identifier":"H2020","grant_number":"101020093","_id":"62781420-2b32-11ec-9570-8d9b63373d4d"}],"oa":1,"tmp":{"short":"CC BY-ND (4.0)","image":"/image/cc_by_nd.png","name":"Creative Commons Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0)","legal_code_url":"https://creativecommons.org/licenses/by-nd/4.0/legalcode"},"degree_awarded":"PhD","supervisor":[{"id":"40876CD8-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-2985-7724","first_name":"Thomas A","last_name":"Henzinger","full_name":"Henzinger, Thomas A"}],"language":[{"iso":"eng"}],"doi":"10.15479/at:ista:11362","month":"05","publication_identifier":{"isbn":["978-3-99078-017-6"]},"publication_status":"published","publisher":"Institute of Science and Technology Austria","department":[{"_id":"GradSch"},{"_id":"ToHe"}],"year":"2022","date_updated":"2023-08-17T06:58:38Z","date_created":"2022-05-12T07:14:01Z","author":[{"id":"3DC22916-F248-11E8-B48F-1D18A9856A87","first_name":"Mathias","last_name":"Lechner","full_name":"Lechner, Mathias"}],"related_material":{"record":[{"relation":"part_of_dissertation","status":"public","id":"10665"},{"status":"public","relation":"part_of_dissertation","id":"10667"},{"relation":"part_of_dissertation","status":"public","id":"11366"},{"relation":"part_of_dissertation","status":"public","id":"7808"},{"relation":"part_of_dissertation","status":"public","id":"10666"}]},"license":"https://creativecommons.org/licenses/by-nd/4.0/","file_date_updated":"2022-05-17T15:19:39Z","ec_funded":1,"page":"124","citation":{"mla":"Lechner, Mathias. Learning Verifiable Representations. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:11362.","short":"M. Lechner, Learning Verifiable Representations, Institute of Science and Technology Austria, 2022.","chicago":"Lechner, Mathias. “Learning Verifiable Representations.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:11362.","ama":"Lechner M. Learning verifiable representations. 2022. doi:10.15479/at:ista:11362","ista":"Lechner M. 2022. Learning verifiable representations. Institute of Science and Technology Austria.","ieee":"M. Lechner, “Learning verifiable representations,” Institute of Science and Technology Austria, 2022.","apa":"Lechner, M. (2022). Learning verifiable representations. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:11362"},"date_published":"2022-05-12T00:00:00Z","keyword":["neural networks","verification","machine learning"],"day":"12","has_accepted_license":"1","article_processing_charge":"No","status":"public","ddc":["004"],"title":"Learning verifiable representations","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","_id":"11362","oa_version":"Published Version","file":[{"access_level":"closed","file_name":"src.zip","content_type":"application/zip","file_size":13210143,"creator":"mlechner","relation":"source_file","file_id":"11378","checksum":"8eefa9c7c10ca7e1a2ccdd731962a645","date_created":"2022-05-13T12:33:26Z","date_updated":"2022-05-13T12:49:00Z"},{"date_updated":"2022-05-17T15:19:39Z","date_created":"2022-05-16T08:02:28Z","checksum":"1b9e1e5a9a83ed9d89dad2f5133dc026","file_id":"11382","relation":"main_file","creator":"mlechner","content_type":"application/pdf","file_size":2732536,"file_name":"thesis_main-a2.pdf","access_level":"open_access"}],"alternative_title":["ISTA Thesis"],"type":"dissertation","abstract":[{"text":"Deep learning has enabled breakthroughs in challenging computing problems and has emerged as the standard problem-solving tool for computer vision and natural language processing tasks.\r\nOne exception to this trend is safety-critical tasks where robustness and resilience requirements contradict the black-box nature of neural networks. \r\nTo deploy deep learning methods for these tasks, it is vital to provide guarantees on neural network agents' safety and robustness criteria. \r\nThis can be achieved by developing formal verification methods to verify the safety and robustness properties of neural networks.\r\n\r\nOur goal is to design, develop and assess safety verification methods for neural networks to improve their reliability and trustworthiness in real-world applications.\r\nThis thesis establishes techniques for the verification of compressed and adversarially trained models as well as the design of novel neural networks for verifiably safe decision-making.\r\n\r\nFirst, we establish the problem of verifying quantized neural networks. Quantization is a technique that trades numerical precision for the computational efficiency of running a neural network and is widely adopted in industry.\r\nWe show that neglecting the reduced precision when verifying a neural network can lead to wrong conclusions about the robustness and safety of the network, highlighting that novel techniques for quantized network verification are necessary. We introduce several bit-exact verification methods explicitly designed for quantized neural networks and experimentally confirm on realistic networks that the network's robustness and other formal properties are affected by the quantization.\r\n\r\nFurthermore, we perform a case study providing evidence that adversarial training, a standard technique for making neural networks more robust, has detrimental effects on the network's performance. This robustness-accuracy tradeoff has been studied before regarding the accuracy obtained on classification datasets where each data point is independent of all other data points. On the other hand, we investigate the tradeoff empirically in robot learning settings where a both, a high accuracy and a high robustness, are desirable.\r\nOur results suggest that the negative side-effects of adversarial training outweigh its robustness benefits in practice.\r\n\r\nFinally, we consider the problem of verifying safety when running a Bayesian neural network policy in a feedback loop with systems over the infinite time horizon. Bayesian neural networks are probabilistic models for learning uncertainties in the data and are therefore often used on robotic and healthcare applications where data is inherently stochastic.\r\nWe introduce a method for recalibrating Bayesian neural networks so that they yield probability distributions over safe decisions only.\r\nOur method learns a safety certificate that guarantees safety over the infinite time horizon to determine which decisions are safe in every possible state of the system.\r\nWe demonstrate the effectiveness of our approach on a series of reinforcement learning benchmarks.","lang":"eng"}]},{"date_published":"2022-07-01T00:00:00Z","page":"138","citation":{"ama":"Mysliwy K. Polarons in Bose gases and polar crystals: Some rigorous energy estimates. 2022. doi:10.15479/at:ista:11473","ista":"Mysliwy K. 2022. Polarons in Bose gases and polar crystals: Some rigorous energy estimates. Institute of Science and Technology Austria.","ieee":"K. Mysliwy, “Polarons in Bose gases and polar crystals: Some rigorous energy estimates,” Institute of Science and Technology Austria, 2022.","apa":"Mysliwy, K. (2022). Polarons in Bose gases and polar crystals: Some rigorous energy estimates. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:11473","mla":"Mysliwy, Krzysztof. Polarons in Bose Gases and Polar Crystals: Some Rigorous Energy Estimates. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:11473.","short":"K. Mysliwy, Polarons in Bose Gases and Polar Crystals: Some Rigorous Energy Estimates, Institute of Science and Technology Austria, 2022.","chicago":"Mysliwy, Krzysztof. “Polarons in Bose Gases and Polar Crystals: Some Rigorous Energy Estimates.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:11473."},"day":"01","has_accepted_license":"1","article_processing_charge":"No","oa_version":"Published Version","file":[{"access_level":"open_access","file_name":"thes1_no_isbn_2_1b.pdf","creator":"kmysliwy","file_size":1830973,"content_type":"application/pdf","file_id":"11486","relation":"main_file","success":1,"checksum":"7970714a20a6052f75fb27a6c3e9976e","date_created":"2022-07-05T08:12:56Z","date_updated":"2022-07-05T08:12:56Z"},{"access_level":"closed","file_name":"thes_source.zip","content_type":"application/zip","file_size":5831060,"creator":"kmysliwy","relation":"source_file","file_id":"11487","checksum":"647a2011fdf56277096c9350fefe1097","date_created":"2022-07-05T08:15:52Z","date_updated":"2022-07-05T08:17:12Z"}],"ddc":["515","539"],"title":"Polarons in Bose gases and polar crystals: Some rigorous energy estimates","status":"public","user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","_id":"11473","abstract":[{"text":"The polaron model is a basic model of quantum field theory describing a single particle\r\ninteracting with a bosonic field. It arises in many physical contexts. We are mostly concerned\r\nwith models applicable in the context of an impurity atom in a Bose-Einstein condensate as\r\nwell as the problem of electrons moving in polar crystals.\r\nThe model has a simple structure in which the interaction of the particle with the field is given\r\nby a term linear in the field’s creation and annihilation operators. In this work, we investigate\r\nthe properties of this model by providing rigorous estimates on various energies relevant to the\r\nproblem. The estimates are obtained, for the most part, by suitable operator techniques which\r\nconstitute the principal mathematical substance of the thesis.\r\nThe first application of these techniques is to derive the polaron model rigorously from first\r\nprinciples, i.e., from a full microscopic quantum-mechanical many-body problem involving an\r\nimpurity in an otherwise homogeneous system. We accomplish this for the N + 1 Bose gas\r\nin the mean-field regime by showing that a suitable polaron-type Hamiltonian arises at weak\r\ninteractions as a low-energy effective theory for this problem.\r\nIn the second part, we investigate rigorously the ground state of the model at fixed momentum\r\nand for large values of the coupling constant. Qualitatively, the system is expected to display\r\na transition from the quasi-particle behavior at small momenta, where the dispersion relation\r\nis parabolic and the particle moves through the medium dragging along a cloud of phonons, to\r\nthe radiative behavior at larger momenta where the polaron decelerates and emits free phonons.\r\nAt the same time, in the strong coupling regime, the bosonic field is expected to behave purely\r\nclassically. Accordingly, the effective mass of the polaron at strong coupling is conjectured to\r\nbe asymptotically equal to the one obtained from the semiclassical counterpart of the problem,\r\nfirst studied by Landau and Pekar in the 1940s. For polaron models with regularized form\r\nfactors and phonon dispersion relations of superfluid type, i.e., bounded below by a linear\r\nfunction of the wavenumbers for all phonon momenta as in the interacting Bose gas, we prove\r\nthat for a large window of momenta below the radiation threshold, the energy-momentum\r\nrelation at strong coupling is indeed essentially a parabola with semi-latus rectum equal to the\r\nLandau–Pekar effective mass, as expected.\r\nFor the Fröhlich polaron describing electrons in polar crystals where the dispersion relation is\r\nof the optical type and the form factor is formally UV–singular due to the nature of the point\r\ncharge-dipole interaction, we are able to give the corresponding upper bound. In contrast to\r\nthe regular case, this requires the inclusion of the quantum fluctuations of the phonon field,\r\nwhich makes the problem considerably more difficult.\r\nThe results are supplemented by studies on the absolute ground-state energy at strong coupling,\r\na proof of the divergence of the effective mass with the coupling constant for a wide class of\r\npolaron models, as well as the discussion of the apparent UV singularity of the Fröhlich model\r\nand the application of the techniques used for its removal for the energy estimates.\r\n","lang":"eng"}],"alternative_title":["ISTA Thesis"],"type":"dissertation","acknowledged_ssus":[{"_id":"SSU"}],"degree_awarded":"PhD","supervisor":[{"first_name":"Robert","last_name":"Seiringer","id":"4AFD0470-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-6781-0521","full_name":"Seiringer, Robert"}],"language":[{"iso":"eng"}],"doi":"10.15479/at:ista:11473","project":[{"call_identifier":"H2020","name":"International IST Doctoral Program","grant_number":"665385","_id":"2564DBCA-B435-11E9-9278-68D0E5697425"}],"oa":1,"month":"07","publication_identifier":{"issn":["2663-337X"]},"date_created":"2022-06-30T12:15:03Z","date_updated":"2023-09-07T13:43:52Z","author":[{"full_name":"Mysliwy, Krzysztof","id":"316457FC-F248-11E8-B48F-1D18A9856A87","first_name":"Krzysztof","last_name":"Mysliwy"}],"related_material":{"record":[{"id":"10564","relation":"part_of_dissertation","status":"public"},{"id":"8705","relation":"part_of_dissertation","status":"public"}]},"publication_status":"published","department":[{"_id":"GradSch"},{"_id":"RoSe"}],"publisher":"Institute of Science and Technology Austria","year":"2022","file_date_updated":"2022-07-05T08:17:12Z","ec_funded":1},{"ec_funded":1,"file_date_updated":"2022-03-10T12:11:48Z","year":"2022","department":[{"_id":"GradSch"},{"_id":"ChLa"}],"publisher":"Institute of Science and Technology Austria","publication_status":"published","related_material":{"record":[{"relation":"part_of_dissertation","status":"public","id":"8724"},{"relation":"part_of_dissertation","status":"public","id":"10803"},{"id":"10802","relation":"part_of_dissertation","status":"public"},{"status":"public","relation":"part_of_dissertation","id":"6590"}]},"author":[{"full_name":"Konstantinov, Nikola H","id":"4B9D76E4-F248-11E8-B48F-1D18A9856A87","first_name":"Nikola H","last_name":"Konstantinov"}],"date_created":"2022-02-28T13:03:49Z","date_updated":"2023-10-17T12:31:54Z","publication_identifier":{"issn":["2663-337X"],"isbn":["978-3-99078-015-2"]},"month":"03","oa":1,"project":[{"name":"International IST Doctoral Program","call_identifier":"H2020","grant_number":"665385","_id":"2564DBCA-B435-11E9-9278-68D0E5697425"}],"doi":"10.15479/at:ista:10799","language":[{"iso":"eng"}],"supervisor":[{"full_name":"Lampert, Christoph","last_name":"Lampert","first_name":"Christoph","orcid":"0000-0001-8622-7887","id":"40C20FD2-F248-11E8-B48F-1D18A9856A87"}],"degree_awarded":"PhD","type":"dissertation","alternative_title":["ISTA Thesis"],"abstract":[{"text":"Because of the increasing popularity of machine learning methods, it is becoming important to understand the impact of learned components on automated decision-making systems and to guarantee that their consequences are beneficial to society. In other words, it is necessary to ensure that machine learning is sufficiently trustworthy to be used in real-world applications. This thesis studies two properties of machine learning models that are highly desirable for the\r\nsake of reliability: robustness and fairness. In the first part of the thesis we study the robustness of learning algorithms to training data corruption. Previous work has shown that machine learning models are vulnerable to a range\r\nof training set issues, varying from label noise through systematic biases to worst-case data manipulations. This is an especially relevant problem from a present perspective, since modern machine learning methods are particularly data hungry and therefore practitioners often have to rely on data collected from various external sources, e.g. from the Internet, from app users or via crowdsourcing. Naturally, such sources vary greatly in the quality and reliability of the\r\ndata they provide. With these considerations in mind, we study the problem of designing machine learning algorithms that are robust to corruptions in data coming from multiple sources. We show that, in contrast to the case of a single dataset with outliers, successful learning within this model is possible both theoretically and practically, even under worst-case data corruptions. The second part of this thesis deals with fairness-aware machine learning. There are multiple areas where machine learning models have shown promising results, but where careful considerations are required, in order to avoid discrimanative decisions taken by such learned components. Ensuring fairness can be particularly challenging, because real-world training datasets are expected to contain various forms of historical bias that may affect the learning process. In this thesis we show that data corruption can indeed render the problem of achieving fairness impossible, by tightly characterizing the theoretical limits of fair learning under worst-case data manipulations. However, assuming access to clean data, we also show how fairness-aware learning can be made practical in contexts beyond binary classification, in particular in the challenging learning to rank setting.","lang":"eng"}],"user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","_id":"10799","ddc":["000"],"title":"Robustness and fairness in machine learning","status":"public","oa_version":"Published Version","file":[{"access_level":"open_access","file_name":"thesis.pdf","file_size":4204905,"content_type":"application/pdf","creator":"nkonstan","relation":"main_file","file_id":"10823","checksum":"626bc523ae8822d20e635d0e2d95182e","success":1,"date_created":"2022-03-06T11:42:54Z","date_updated":"2022-03-06T11:42:54Z"},{"date_updated":"2022-03-10T12:11:48Z","date_created":"2022-03-06T11:42:57Z","checksum":"e2ca2b88350ac8ea1515b948885cbcb1","file_id":"10824","relation":"source_file","creator":"nkonstan","file_size":22841103,"content_type":"application/x-zip-compressed","file_name":"thesis.zip","access_level":"closed"}],"keyword":["robustness","fairness","machine learning","PAC learning","adversarial learning"],"has_accepted_license":"1","article_processing_charge":"No","day":"08","citation":{"chicago":"Konstantinov, Nikola H. “Robustness and Fairness in Machine Learning.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:10799.","short":"N.H. Konstantinov, Robustness and Fairness in Machine Learning, Institute of Science and Technology Austria, 2022.","mla":"Konstantinov, Nikola H. Robustness and Fairness in Machine Learning. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:10799.","apa":"Konstantinov, N. H. (2022). Robustness and fairness in machine learning. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:10799","ieee":"N. H. Konstantinov, “Robustness and fairness in machine learning,” Institute of Science and Technology Austria, 2022.","ista":"Konstantinov NH. 2022. Robustness and fairness in machine learning. Institute of Science and Technology Austria.","ama":"Konstantinov NH. Robustness and fairness in machine learning. 2022. doi:10.15479/at:ista:10799"},"page":"176","date_published":"2022-03-08T00:00:00Z"},{"oa_version":"Published Version","file":[{"date_created":"2022-07-25T09:08:47Z","date_updated":"2022-07-25T09:08:47Z","checksum":"bd7ac35403cf5b4b2607287d2a104b3a","relation":"main_file","file_id":"11645","content_type":"application/pdf","file_size":9730864,"creator":"mgallei","file_name":"Thesis_Gallei.pdf","access_level":"open_access"},{"access_level":"closed","file_name":"Thesis_Gallei_source.docx","creator":"mgallei","content_type":"application/vnd.openxmlformats-officedocument.wordprocessingml.document","file_size":19560720,"file_id":"11646","relation":"source_file","checksum":"a9e54fe5471ba25dc13c2150c1b8ccbb","date_updated":"2022-07-25T09:39:58Z","date_created":"2022-07-25T09:09:09Z"},{"file_id":"11647","relation":"source_file","date_created":"2022-07-25T09:09:32Z","date_updated":"2022-07-25T09:39:58Z","checksum":"3994f7f20058941b5bb8a16886b21e71","description":"This is the print version of the thesis including the full appendix","file_name":"Thesis_Gallei_to_print.pdf","access_level":"closed","creator":"mgallei","content_type":"application/pdf","file_size":24542837},{"relation":"main_file","file_id":"11650","checksum":"f24acd3c0d864f4c6676e8b0d7bfa76b","date_created":"2022-07-25T11:48:45Z","date_updated":"2022-07-25T11:48:45Z","access_level":"open_access","file_name":"Thesis_Gallei_Appendix.pdf","content_type":"application/pdf","file_size":15435966,"creator":"mgallei"}],"user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","_id":"11626","status":"public","title":"Auxin and strigolactone non-canonical signaling regulating development in Arabidopsis thaliana","ddc":["575"],"abstract":[{"text":"Plant growth and development is well known to be both, flexible and dynamic. The high capacity for post-embryonic organ formation and tissue regeneration requires tightly regulated intercellular communication and coordinated tissue polarization. One of the most important drivers for patterning and polarity in plant development is the phytohormone auxin. Auxin has the unique characteristic to establish polarized channels for its own active directional cell to cell transport. This fascinating phenomenon is called auxin canalization. Those auxin transport channels are characterized by the expression and polar, subcellular localization of PIN auxin efflux carriers. PIN proteins have the ability to dynamically change their localization and auxin itself can affect this by interfering with trafficking. Most of the underlying molecular mechanisms of canalization still remain enigmatic. What is known so far is that canonical auxin signaling is indispensable but also other non-canonical signaling components are thought to play a role. In order to shed light into the mysteries auf auxin canalization this study revisits the branches of auxin signaling in detail. Further a new auxin analogue, PISA, is developed which triggers auxin-like responses but does not directly activate canonical transcriptional auxin signaling. We revisit the direct auxin effect on PIN trafficking where we found that, contradictory to previous observations, auxin is very specifically promoting endocytosis of PIN2 but has no overall effect on endocytosis. Further, we evaluate which cellular processes related to PIN subcellular dynamics are involved in the establishment of auxin conducting channels and the formation of vascular tissue. We are re-evaluating the function of AUXIN BINDING PROTEIN 1 (ABP1) and provide a comprehensive picture about its developmental phneotypes and involvement in auxin signaling and canalization. Lastly, we are focusing on the crosstalk between the hormone strigolactone (SL) and auxin and found that SL is interfering with essentially all processes involved in auxin canalization in a non-transcriptional manner. Lastly we identify a new way of SL perception and signaling which is emanating from mitochondria, is independent of canonical SL signaling and is modulating primary root growth.","lang":"eng"}],"type":"dissertation","alternative_title":["ISTA Thesis"],"date_published":"2022-07-20T00:00:00Z","citation":{"ista":"Gallei MC. 2022. Auxin and strigolactone non-canonical signaling regulating development in Arabidopsis thaliana. Institute of Science and Technology Austria.","ieee":"M. C. Gallei, “Auxin and strigolactone non-canonical signaling regulating development in Arabidopsis thaliana,” Institute of Science and Technology Austria, 2022.","apa":"Gallei, M. C. (2022). Auxin and strigolactone non-canonical signaling regulating development in Arabidopsis thaliana. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:11626","ama":"Gallei MC. Auxin and strigolactone non-canonical signaling regulating development in Arabidopsis thaliana. 2022. doi:10.15479/at:ista:11626","chicago":"Gallei, Michelle C. “Auxin and Strigolactone Non-Canonical Signaling Regulating Development in Arabidopsis Thaliana.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:11626.","mla":"Gallei, Michelle C. Auxin and Strigolactone Non-Canonical Signaling Regulating Development in Arabidopsis Thaliana. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:11626.","short":"M.C. Gallei, Auxin and Strigolactone Non-Canonical Signaling Regulating Development in Arabidopsis Thaliana, Institute of Science and Technology Austria, 2022."},"page":"248","day":"20","has_accepted_license":"1","article_processing_charge":"No","author":[{"first_name":"Michelle C","last_name":"Gallei","id":"35A03822-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-1286-7368","full_name":"Gallei, Michelle C"}],"related_material":{"record":[{"status":"public","relation":"part_of_dissertation","id":"8931"},{"status":"public","relation":"part_of_dissertation","id":"9287"},{"relation":"part_of_dissertation","status":"public","id":"7142"},{"status":"public","relation":"part_of_dissertation","id":"7465"},{"id":"8138","status":"public","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","status":"public","id":"6260"},{"status":"public","relation":"part_of_dissertation","id":"10411"}]},"date_updated":"2023-11-07T08:20:13Z","date_created":"2022-07-20T11:21:53Z","year":"2022","publication_status":"published","publisher":"Institute of Science and Technology Austria","department":[{"_id":"GradSch"},{"_id":"JiFr"}],"file_date_updated":"2022-07-25T11:48:45Z","ec_funded":1,"doi":"10.15479/at:ista:11626","supervisor":[{"orcid":"0000-0002-8302-7596","id":"4159519E-F248-11E8-B48F-1D18A9856A87","last_name":"Friml","first_name":"Jiří","full_name":"Friml, Jiří"},{"orcid":"0000-0002-8510-9739","id":"38F4F166-F248-11E8-B48F-1D18A9856A87","last_name":"Benková","first_name":"Eva","full_name":"Benková, Eva"},{"first_name":"Eilon","last_name":"Shani","full_name":"Shani, Eilon"}],"degree_awarded":"PhD","language":[{"iso":"eng"}],"oa":1,"project":[{"grant_number":"742985","_id":"261099A6-B435-11E9-9278-68D0E5697425","call_identifier":"H2020","name":"Tracing Evolution of Auxin Transport and Polarity in Plants"}],"month":"07","publication_identifier":{"issn":["2663-337X"],"isbn":["978-3-99078-019-0"]}},{"date_updated":"2024-02-28T12:57:46Z","date_created":"2023-01-24T10:49:46Z","author":[{"id":"4DD40360-F248-11E8-B48F-1D18A9856A87","last_name":"Sperl","first_name":"Georg","full_name":"Sperl, Georg"}],"related_material":{"record":[{"status":"public","relation":"part_of_dissertation","id":"11736"},{"id":"9818","status":"public","relation":"part_of_dissertation"},{"id":"8385","relation":"part_of_dissertation","status":"public"}]},"publication_status":"published","publisher":"Institute of Science and Technology Austria","department":[{"_id":"GradSch"},{"_id":"ChWo"}],"year":"2022","file_date_updated":"2023-02-02T09:39:25Z","ec_funded":1,"degree_awarded":"PhD","acknowledged_ssus":[{"_id":"SSU"}],"supervisor":[{"full_name":"Wojtan, Christopher J","last_name":"Wojtan","first_name":"Christopher J","orcid":"0000-0001-6646-5546","id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87"}],"language":[{"iso":"eng"}],"doi":"10.15479/at:ista:12103","project":[{"call_identifier":"H2020","name":"Efficient Simulation of Natural Phenomena at Extremely Large Scales","_id":"2533E772-B435-11E9-9278-68D0E5697425","grant_number":"638176"}],"oa":1,"month":"09","publication_identifier":{"isbn":["978-3-99078-020-6"],"issn":["2663-337X"]},"oa_version":"Published Version","file":[{"description":"This is the main PDF file of the thesis. File size: 105 MB","file_name":"thesis_gsperl.pdf","access_level":"open_access","creator":"cchlebak","file_size":104497530,"content_type":"application/pdf","file_id":"12371","title":"Thesis","relation":"main_file","date_created":"2023-01-25T12:04:41Z","date_updated":"2023-02-02T09:29:57Z","checksum":"083722acbb8115e52e3b0fdec6226769"},{"content_type":"application/pdf","file_size":23183710,"creator":"cchlebak","access_level":"open_access","file_name":"thesis_gsperl_compressed.pdf","description":"This version of the thesis uses stronger image compression for a smaller file size of 23MB.","checksum":"511f82025e5fcb70bff4731d6896ca07","date_updated":"2023-02-02T09:33:37Z","date_created":"2023-02-02T09:33:37Z","relation":"main_file","file_id":"12483","title":"Thesis (compressed 23MB)"},{"file_id":"12484","relation":"source_file","date_updated":"2023-02-02T09:39:25Z","date_created":"2023-02-02T09:39:25Z","checksum":"ed4cb85225eedff761c25bddfc37a2ed","file_name":"thesis-source.zip","access_level":"open_access","creator":"cchlebak","content_type":"application/x-zip-compressed","file_size":98382247}],"ddc":["000","620"],"title":"Homogenizing yarn simulations: Large-scale mechanics, small-scale detail, and quantitative fitting","status":"public","_id":"12358","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","abstract":[{"lang":"eng","text":"The complex yarn structure of knitted and woven fabrics gives rise to both a mechanical and\r\nvisual complexity. The small-scale interactions of yarns colliding with and pulling on each\r\nother result in drastically different large-scale stretching and bending behavior, introducing\r\nanisotropy, curling, and more. While simulating cloth as individual yarns can reproduce this\r\ncomplexity and match the quality of real fabric, it may be too computationally expensive for\r\nlarge fabrics. On the other hand, continuum-based approaches do not need to discretize the\r\ncloth at a stitch-level, but it is non-trivial to find a material model that would replicate the\r\nlarge-scale behavior of yarn fabrics, and they discard the intricate visual detail. In this thesis,\r\nwe discuss three methods to try and bridge the gap between small-scale and large-scale yarn\r\nmechanics using numerical homogenization: fitting a continuum model to periodic yarn simulations, adding mechanics-aware yarn detail onto thin-shell simulations, and quantitatively\r\nfitting yarn parameters to physical measurements of real fabric.\r\nTo start, we present a method for animating yarn-level cloth effects using a thin-shell solver.\r\nWe first use a large number of periodic yarn-level simulations to build a model of the potential\r\nenergy density of the cloth, and then use it to compute forces in a thin-shell simulator. The\r\nresulting simulations faithfully reproduce expected effects like the stiffening of woven fabrics\r\nand the highly deformable nature and anisotropy of knitted fabrics at a fraction of the cost of\r\nfull yarn-level simulation.\r\nWhile our thin-shell simulations are able to capture large-scale yarn mechanics, they lack\r\nthe rich visual detail of yarn-level simulations. Therefore, we propose a method to animate\r\nyarn-level cloth geometry on top of an underlying deforming mesh in a mechanics-aware\r\nfashion in real time. Using triangle strains to interpolate precomputed yarn geometry, we are\r\nable to reproduce effects such as knit loops tightening under stretching at negligible cost.\r\nFinally, we introduce a methodology for inverse-modeling of yarn-level mechanics of cloth,\r\nbased on the mechanical response of fabrics in the real world. We compile a database from\r\nphysical tests of several knitted fabrics used in the textile industry spanning diverse physical\r\nproperties like stiffness, nonlinearity, and anisotropy. We then develop a system for approximating these mechanical responses with yarn-level cloth simulation, using homogenized\r\nshell models to speed up computation and adding some small-but-necessary extensions to\r\nyarn-level models used in computer graphics.\r\n"}],"alternative_title":["ISTA Thesis"],"type":"dissertation","date_published":"2022-09-22T00:00:00Z","page":"138","citation":{"chicago":"Sperl, Georg. “Homogenizing Yarn Simulations: Large-Scale Mechanics, Small-Scale Detail, and Quantitative Fitting.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:12103.","short":"G. Sperl, Homogenizing Yarn Simulations: Large-Scale Mechanics, Small-Scale Detail, and Quantitative Fitting, Institute of Science and Technology Austria, 2022.","mla":"Sperl, Georg. Homogenizing Yarn Simulations: Large-Scale Mechanics, Small-Scale Detail, and Quantitative Fitting. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:12103.","ieee":"G. Sperl, “Homogenizing yarn simulations: Large-scale mechanics, small-scale detail, and quantitative fitting,” Institute of Science and Technology Austria, 2022.","apa":"Sperl, G. (2022). Homogenizing yarn simulations: Large-scale mechanics, small-scale detail, and quantitative fitting. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12103","ista":"Sperl G. 2022. Homogenizing yarn simulations: Large-scale mechanics, small-scale detail, and quantitative fitting. Institute of Science and Technology Austria.","ama":"Sperl G. Homogenizing yarn simulations: Large-scale mechanics, small-scale detail, and quantitative fitting. 2022. doi:10.15479/at:ista:12103"},"day":"22","has_accepted_license":"1","article_processing_charge":"No"},{"file":[{"date_updated":"2022-02-22T07:20:12Z","date_created":"2022-02-21T13:58:16Z","checksum":"0fc54ad1eaede879c665ac9b53c93e22","relation":"source_file","file_id":"10785","content_type":"application/zip","file_size":17668233,"creator":"wrzadkow","file_name":"Rzadkowski_thesis_final_source.zip","access_level":"closed"},{"date_created":"2022-02-21T14:02:54Z","date_updated":"2022-02-21T14:02:54Z","checksum":"22d2d7af37ca31f6b1730c26cac7bced","success":1,"relation":"main_file","file_id":"10786","content_type":"application/pdf","file_size":13307331,"creator":"wrzadkow","file_name":"Rzadkowski_thesis_final.pdf","access_level":"open_access"}],"oa_version":"Published Version","user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","_id":"10759","title":"Analytic and machine learning approaches to composite quantum impurities","status":"public","ddc":["530"],"abstract":[{"lang":"eng","text":"In this Thesis, I study composite quantum impurities with variational techniques, both inspired by machine learning as well as fully analytic. I supplement this with exploration of other applications of machine learning, in particular artificial neural networks, in many-body physics. In Chapters 3 and 4, I study quasiparticle systems with variational approach. I derive a Hamiltonian describing the angulon quasiparticle in the presence of a magnetic field. I apply analytic variational treatment to this Hamiltonian. Then, I introduce a variational approach for non-additive systems, based on artificial neural networks. I exemplify this approach on the example of the polaron quasiparticle (Fröhlich Hamiltonian). In Chapter 5, I continue using artificial neural networks, albeit in a different setting. I apply artificial neural networks to detect phases from snapshots of two types physical systems. Namely, I study Monte Carlo snapshots of multilayer classical spin models as well as molecular dynamics maps of colloidal systems. The main type of networks that I use here are convolutional neural networks, known for their applicability to image data."}],"type":"dissertation","alternative_title":["ISTA Thesis"],"date_published":"2022-02-21T00:00:00Z","citation":{"chicago":"Rzadkowski, Wojciech. “Analytic and Machine Learning Approaches to Composite Quantum Impurities.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:10759.","short":"W. Rzadkowski, Analytic and Machine Learning Approaches to Composite Quantum Impurities, Institute of Science and Technology Austria, 2022.","mla":"Rzadkowski, Wojciech. Analytic and Machine Learning Approaches to Composite Quantum Impurities. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:10759.","apa":"Rzadkowski, W. (2022). Analytic and machine learning approaches to composite quantum impurities. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:10759","ieee":"W. Rzadkowski, “Analytic and machine learning approaches to composite quantum impurities,” Institute of Science and Technology Austria, 2022.","ista":"Rzadkowski W. 2022. Analytic and machine learning approaches to composite quantum impurities. Institute of Science and Technology Austria.","ama":"Rzadkowski W. Analytic and machine learning approaches to composite quantum impurities. 2022. doi:10.15479/at:ista:10759"},"page":"120","has_accepted_license":"1","article_processing_charge":"No","day":"21","related_material":{"record":[{"relation":"part_of_dissertation","status":"public","id":"10762"},{"relation":"part_of_dissertation","status":"public","id":"8644"},{"id":"7956","relation":"part_of_dissertation","status":"public"},{"status":"public","relation":"part_of_dissertation","id":"415"}]},"author":[{"full_name":"Rzadkowski, Wojciech","last_name":"Rzadkowski","first_name":"Wojciech","orcid":"0000-0002-1106-4419","id":"48C55298-F248-11E8-B48F-1D18A9856A87"}],"date_created":"2022-02-16T13:27:37Z","date_updated":"2024-02-28T13:01:59Z","year":"2022","department":[{"_id":"GradSch"},{"_id":"MiLe"}],"publisher":"Institute of Science and Technology Austria","publication_status":"published","ec_funded":1,"file_date_updated":"2022-02-22T07:20:12Z","doi":"10.15479/at:ista:10759","language":[{"iso":"eng"}],"degree_awarded":"PhD","supervisor":[{"id":"37CB05FA-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-6990-7802","first_name":"Mikhail","last_name":"Lemeshko","full_name":"Lemeshko, Mikhail"}],"oa":1,"project":[{"grant_number":"665385","_id":"2564DBCA-B435-11E9-9278-68D0E5697425","call_identifier":"H2020","name":"International IST Doctoral Program"}],"publication_identifier":{"issn":["2663-337X"]},"month":"02"}]