[{"citation":{"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.","ista":"Matejovicova L. 2022. Genetic basis of flower colour as a model for adaptive evolution. Institute of Science and Technology Austria.","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.","short":"L. Matejovicova, Genetic Basis of Flower Colour as a Model for Adaptive Evolution, Institute of Science and Technology Austria, 2022.","ieee":"L. Matejovicova, “Genetic basis of flower colour as a model for adaptive evolution,” Institute of Science and Technology Austria, 2022.","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"},"user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","author":[{"id":"2DFDEC72-F248-11E8-B48F-1D18A9856A87","first_name":"Lenka","full_name":"Matejovicova, Lenka","last_name":"Matejovicova"}],"article_processing_charge":"No","title":"Genetic basis of flower colour as a model for adaptive evolution","has_accepted_license":"1","year":"2022","day":"06","page":"112","date_published":"2022-04-06T00:00:00Z","doi":"10.15479/at:ista:11128","date_created":"2022-04-07T08:19:54Z","publisher":"Institute of Science and Technology Austria","oa":1,"supervisor":[{"id":"4880FE40-F248-11E8-B48F-1D18A9856A87","first_name":"Nicholas H","orcid":"0000-0002-8548-5240","full_name":"Barton, Nicholas H","last_name":"Barton"}],"date_updated":"2023-06-23T06:26:41Z","ddc":["576","582"],"department":[{"_id":"GradSch"},{"_id":"NiBa"}],"file_date_updated":"2022-04-07T08:11:51Z","_id":"11128","type":"dissertation","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"status":"public","publication_identifier":{"issn":["2663-337X"],"isbn":["978-3-99078-016-9"]},"publication_status":"published","degree_awarded":"PhD","file":[{"checksum":"e9609bc4e8f8e20146fc1125fd4f1bf7","file_id":"11129","relation":"main_file","access_level":"open_access","content_type":"application/pdf","file_name":"LenkaPhD_Official_PDFA.pdf","date_created":"2022-04-07T08:11:34Z","creator":"cchlebak","file_size":11906472,"date_updated":"2022-04-07T08:11:34Z"},{"access_level":"closed","relation":"source_file","content_type":"application/x-zip-compressed","checksum":"99d67040432fd07a225643a212ee8588","file_id":"11130","creator":"cchlebak","date_updated":"2022-04-07T08:11:51Z","file_size":23036766,"date_created":"2022-04-07T08:11:51Z","file_name":"LenkaPhD Official_source.zip"}],"language":[{"iso":"eng"}],"license":"https://creativecommons.org/licenses/by/4.0/","acknowledged_ssus":[{"_id":"ScienComp"},{"_id":"Bio"}],"abstract":[{"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.","lang":"eng"}],"oa_version":"Published Version","alternative_title":["ISTA Thesis"],"month":"04"},{"date_published":"2022-08-23T00:00:00Z","doi":"10.15479/at:ista:11945","date_created":"2022-08-23T11:33:11Z","page":"133","day":"23","has_accepted_license":"1","year":"2022","publisher":"Institute of Science and Technology Austria","oa":1,"title":"Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function","author":[{"first_name":"Rouven","id":"4C5E7B96-F248-11E8-B48F-1D18A9856A87","full_name":"Schulz, Rouven","orcid":"0000-0001-5297-733X","last_name":"Schulz"}],"article_processing_charge":"No","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","citation":{"short":"R. Schulz, Chimeric G Protein-Coupled Receptors Mimic Distinct Signaling Pathways and Modulate Microglia Function, Institute of Science and Technology Austria, 2022.","ieee":"R. Schulz, “Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function,” Institute of Science and Technology Austria, 2022.","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","ama":"Schulz R. Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function. 2022. doi:10.15479/at:ista:11945","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.","ista":"Schulz R. 2022. Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function. Institute of Science and Technology Austria.","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."},"project":[{"_id":"267F75D8-B435-11E9-9278-68D0E5697425","name":"Modulating microglia through G protein-coupled receptor (GPCR) signaling"}],"related_material":{"record":[{"id":"11995","status":"public","relation":"dissertation_contains"}]},"file":[{"creator":"rschulz","file_size":28079331,"date_updated":"2022-08-25T08:59:57Z","file_name":"Thesis_Rouven_Schulz_2022_final.pdf","date_created":"2022-08-25T08:59:57Z","relation":"main_file","access_level":"open_access","content_type":"application/pdf","success":1,"file_id":"11970","checksum":"61b1b666a210ff7cdd0e95ea75207a13"},{"checksum":"2b8f95ea1c134dbdb927b41b1dbeeeb5","file_id":"11971","relation":"source_file","access_level":"closed","content_type":"application/vnd.openxmlformats-officedocument.wordprocessingml.document","file_name":"Thesis_Rouven_Schulz_2022_final.docx","date_created":"2022-08-25T09:00:11Z","creator":"rschulz","file_size":27226963,"date_updated":"2022-08-25T09:33:31Z"}],"language":[{"iso":"eng"}],"publication_identifier":{"issn":["2663-337X"]},"degree_awarded":"PhD","publication_status":"published","month":"08","alternative_title":["ISTA Thesis"],"oa_version":"Published Version","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."}],"acknowledged_ssus":[{"_id":"Bio"},{"_id":"PreCl"},{"_id":"LifeSc"}],"department":[{"_id":"GradSch"},{"_id":"SaSi"}],"file_date_updated":"2022-08-25T09:33:31Z","ddc":["570"],"supervisor":[{"orcid":"0000-0001-8635-0877","full_name":"Siegert, Sandra","last_name":"Siegert","id":"36ACD32E-F248-11E8-B48F-1D18A9856A87","first_name":"Sandra"}],"date_updated":"2023-08-03T13:02:26Z","status":"public","type":"dissertation","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"_id":"11945"},{"citation":{"ista":"Brooks M. 2022. Translation-invariant quantum systems with effectively broken symmetry. Institute of Science and Technology Austria.","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.","short":"M. Brooks, Translation-Invariant Quantum Systems with Effectively Broken Symmetry, Institute of Science and Technology Austria, 2022.","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","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","mla":"Brooks, Morris. Translation-Invariant Quantum Systems with Effectively Broken Symmetry. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:12390."},"user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","author":[{"first_name":"Morris","id":"B7ECF9FC-AA38-11E9-AC9A-0930E6697425","full_name":"Brooks, Morris","orcid":"0000-0002-6249-0928","last_name":"Brooks"}],"article_processing_charge":"No","title":"Translation-invariant quantum systems with effectively broken symmetry","project":[{"name":"Analysis of quantum many-body systems","grant_number":"694227","call_identifier":"H2020","_id":"25C6DC12-B435-11E9-9278-68D0E5697425"}],"has_accepted_license":"1","year":"2022","day":"15","page":"196","date_published":"2022-12-15T00:00:00Z","doi":"10.15479/at:ista:12390","date_created":"2023-01-26T10:00:42Z","publisher":"Institute of Science and Technology Austria","oa":1,"supervisor":[{"full_name":"Seiringer, Robert","orcid":"0000-0002-6781-0521","last_name":"Seiringer","id":"4AFD0470-F248-11E8-B48F-1D18A9856A87","first_name":"Robert"}],"date_updated":"2023-08-07T13:32:09Z","ddc":["500"],"file_date_updated":"2023-01-26T10:02:42Z","department":[{"_id":"GradSch"},{"_id":"RoSe"}],"_id":"12390","type":"dissertation","tmp":{"name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","image":"/images/cc_by_nc_sa.png","legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","short":"CC BY-NC-SA (4.0)"},"status":"public","publication_identifier":{"issn":["2663-337X"]},"degree_awarded":"PhD","publication_status":"published","file":[{"file_id":"12391","checksum":"b31460e937f33b557abb40ebef02b567","success":1,"content_type":"application/pdf","access_level":"open_access","relation":"main_file","date_created":"2023-01-26T10:02:34Z","file_name":"Brooks_Thesis.pdf","date_updated":"2023-01-26T10:02:34Z","file_size":3095225,"creator":"cchlebak"},{"creator":"cchlebak","file_size":809842,"date_updated":"2023-01-26T10:02:42Z","file_name":"Brooks_Thesis.tex","date_created":"2023-01-26T10:02:42Z","relation":"source_file","access_level":"closed","content_type":"application/octet-stream","file_id":"12392","checksum":"9751869fa5e7981588ad4228f4fd4bd6"}],"language":[{"iso":"eng"}],"related_material":{"record":[{"id":"9005","status":"public","relation":"part_of_dissertation"}]},"ec_funded":1,"license":"https://creativecommons.org/licenses/by-nc-sa/4.0/","abstract":[{"lang":"eng","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"}],"oa_version":"Published Version","alternative_title":["ISTA Thesis"],"month":"12"},{"author":[{"first_name":"Feyza N","id":"49DA7910-F248-11E8-B48F-1D18A9856A87","last_name":"Arslan","full_name":"Arslan, Feyza N","orcid":"0000-0001-5809-9566"}],"article_processing_charge":"No","title":"Remodeling of E-cadherin-mediated contacts via cortical flows","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.","ista":"Arslan FN. 2022. Remodeling of E-cadherin-mediated contacts via cortical flows. Institute of Science and Technology Austria.","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.","ama":"Arslan FN. Remodeling of E-cadherin-mediated contacts via cortical flows. 2022. doi:10.15479/at:ista:12153","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","short":"F.N. Arslan, Remodeling of E-Cadherin-Mediated Contacts via Cortical Flows, Institute of Science and Technology Austria, 2022.","ieee":"F. N. Arslan, “Remodeling of E-cadherin-mediated contacts via cortical flows,” Institute of Science and Technology Austria, 2022."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","project":[{"call_identifier":"H2020","_id":"260F1432-B435-11E9-9278-68D0E5697425","grant_number":"742573","name":"Interaction and feedback between cell mechanics and fate specification in vertebrate gastrulation"}],"page":"113","doi":"10.15479/at:ista:12153","date_published":"2022-09-29T00:00:00Z","date_created":"2023-01-25T10:43:24Z","has_accepted_license":"1","year":"2022","day":"29","publisher":"Institute of Science and Technology Austria","oa":1,"file_date_updated":"2023-01-25T10:52:46Z","department":[{"_id":"GradSch"},{"_id":"CaHe"}],"supervisor":[{"last_name":"Heisenberg","full_name":"Heisenberg, Carl-Philipp J","orcid":"0000-0002-0912-4566","id":"39427864-F248-11E8-B48F-1D18A9856A87","first_name":"Carl-Philipp J"}],"date_updated":"2023-08-08T13:14:10Z","ddc":["570"],"type":"dissertation","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"status":"public","_id":"12368","related_material":{"record":[{"relation":"part_of_dissertation","status":"public","id":"9350"}]},"ec_funded":1,"publication_identifier":{"issn":["2663-337X"],"isbn":[" 978-3-99078-025-1 "]},"publication_status":"published","degree_awarded":"PhD","file":[{"success":1,"file_id":"12369","checksum":"e54a3e69b83ebf166544164afd25608e","content_type":"application/pdf","relation":"main_file","access_level":"open_access","file_name":"THESIS_FINAL_FArslan_pdfa.pdf","date_created":"2023-01-25T10:52:46Z","file_size":14581024,"date_updated":"2023-01-25T10:52:46Z","creator":"cchlebak"}],"language":[{"iso":"eng"}],"alternative_title":["ISTA Thesis"],"month":"09","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."}],"acknowledged_ssus":[{"_id":"LifeSc"},{"_id":"Bio"},{"_id":"NanoFab"}],"oa_version":"Published Version"},{"project":[{"grant_number":"Z211","name":"The Wittgenstein Prize","_id":"25F42A32-B435-11E9-9278-68D0E5697425","call_identifier":"FWF"},{"name":"Vigilant Algorithmic Monitoring of Software","grant_number":"101020093","_id":"62781420-2b32-11ec-9570-8d9b63373d4d","call_identifier":"H2020"}],"citation":{"chicago":"Lechner, Mathias. “Learning Verifiable Representations.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:11362.","ista":"Lechner M. 2022. Learning verifiable representations. Institute of Science and Technology Austria.","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.","ieee":"M. Lechner, “Learning verifiable representations,” Institute of Science and Technology Austria, 2022.","ama":"Lechner M. Learning verifiable representations. 2022. doi:10.15479/at:ista:11362","apa":"Lechner, M. (2022). Learning verifiable representations. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:11362"},"user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","author":[{"full_name":"Lechner, Mathias","last_name":"Lechner","id":"3DC22916-F248-11E8-B48F-1D18A9856A87","first_name":"Mathias"}],"article_processing_charge":"No","title":"Learning verifiable representations","publisher":"Institute of Science and Technology Austria","oa":1,"has_accepted_license":"1","year":"2022","day":"12","page":"124","doi":"10.15479/at:ista:11362","date_published":"2022-05-12T00:00:00Z","date_created":"2022-05-12T07:14:01Z","_id":"11362","type":"dissertation","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nd/4.0/legalcode","image":"/image/cc_by_nd.png","name":"Creative Commons Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0)","short":"CC BY-ND (4.0)"},"status":"public","keyword":["neural networks","verification","machine learning"],"supervisor":[{"last_name":"Henzinger","orcid":"0000-0002-2985-7724","full_name":"Henzinger, Thomas A","first_name":"Thomas A","id":"40876CD8-F248-11E8-B48F-1D18A9856A87"}],"date_updated":"2023-08-17T06:58:38Z","ddc":["004"],"file_date_updated":"2022-05-17T15:19:39Z","department":[{"_id":"GradSch"},{"_id":"ToHe"}],"abstract":[{"lang":"eng","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."}],"oa_version":"Published Version","alternative_title":["ISTA Thesis"],"month":"05","publication_identifier":{"isbn":["978-3-99078-017-6"]},"degree_awarded":"PhD","publication_status":"published","file":[{"checksum":"8eefa9c7c10ca7e1a2ccdd731962a645","file_id":"11378","content_type":"application/zip","access_level":"closed","relation":"source_file","date_created":"2022-05-13T12:33:26Z","file_name":"src.zip","date_updated":"2022-05-13T12:49:00Z","file_size":13210143,"creator":"mlechner"},{"date_updated":"2022-05-17T15:19:39Z","file_size":2732536,"creator":"mlechner","date_created":"2022-05-16T08:02:28Z","file_name":"thesis_main-a2.pdf","content_type":"application/pdf","access_level":"open_access","relation":"main_file","checksum":"1b9e1e5a9a83ed9d89dad2f5133dc026","file_id":"11382"}],"language":[{"iso":"eng"}],"related_material":{"record":[{"relation":"part_of_dissertation","id":"10665","status":"public"},{"relation":"part_of_dissertation","id":"10667","status":"public"},{"status":"public","id":"11366","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","id":"7808","status":"public"},{"id":"10666","status":"public","relation":"part_of_dissertation"}]},"license":"https://creativecommons.org/licenses/by-nd/4.0/","ec_funded":1}]