Efficient logspace classes for enumeration, counting and uniform generation
dc.contributor.advisor | Arenas Saavedra, Marcelo Alejandro | |
dc.contributor.author | Croquevielle Rendic, Luis Alberto | |
dc.contributor.other | Pontificia Universidad Católica de Chile. Escuela de Ingeniería | |
dc.date.accessioned | 2022-10-07T20:10:07Z | |
dc.date.available | 2022-10-07T20:10:07Z | |
dc.date.issued | 2019 | |
dc.description | Tesis (Master of Science in Engineering)--Pontificia Universidad Católica de Chile, 2019 | |
dc.description.abstract | In this work, we study two simple yet general complexity classes, based on logspace Turing machines, which provide a unifying framework for efficient query evaluation in areas like information extraction and graph databases, among others. We investigate the complexity of three fundamental algorithmic problems for these classes: enumeration, counting and uniform generation of solutions, and show that they have several desirable properties in this respect. Both complexity classes are defined in terms of non-deterministic logspace transducers (NL-transducers). For the first class, we consider the case of unambiguous NL-transducers, and we prove constant delay enumeration, and both counting and uniform generation of solutions in polynomial time. For the second class, we consider unrestricted NL-transducers, and we obtain polynomial delay enumeration, approximate counting in polynomial time, and polynomial-time randomized algorithms for uniform generation. More specifically, we show that each problem in this second class admits a fully polynomial-time randomized approximation scheme (FPRAS) and a polynomial-time Las Vegas algorithm for uniform generation. Interestingly, the key idea to prove these results is to show that the fundamental problem #NFA admits an FPRAS, where #NFA is the problem of counting the number of strings of length n accepted by a non-deterministic finite automaton (NFA). While this problem is known to be #P-complete and, more precisely, SPANL-complete, it was open whether this problem admits an FPRAS. In this work, we solve this open problem, and obtain as a welcome corollary that every function in SPANL admits an FPRAS. | |
dc.format.extent | x, 77 páginas | |
dc.fuente.origen | SRIA | |
dc.identifier.doi | 10.7764/tesisUC/ING/65006 | |
dc.identifier.uri | https://doi.org/10.7764/tesisUC/ING/65006 | |
dc.identifier.uri | https://repositorio.uc.cl/handle/11534/65006 | |
dc.information.autoruc | Escuela de ingeniería ; Arenas Saavedra, Marcelo Alejandro ; S/I ; 81488 | |
dc.information.autoruc | Escuela de ingeniería ; Croquevielle Rendic, Luis Alberto ; S/I ; 203873 | |
dc.language.iso | en | |
dc.nota.acceso | Contenido completo | |
dc.rights | acceso abierto | |
dc.subject | Logspace transducers | es_ES |
dc.subject | Constant delay enumeration | es_ES |
dc.subject | Approximate counting | es_ES |
dc.subject | Uniform generation | es_ES |
dc.subject.ddc | 620 | |
dc.subject.dewey | Ingeniería | es_ES |
dc.title | Efficient logspace classes for enumeration, counting and uniform generation | es_ES |
dc.type | tesis de maestría | |
sipa.codpersvinculados | 81488 | |
sipa.codpersvinculados | 203873 |