• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • Tagged with
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Finite Herbrand Models for Restricted First-Order Clauses

Borgwardt, Stefan, Morawska, Barbara 20 June 2022 (has links)
We call a Herbrand model of a set of first-order clauses finite, if each of the predicates in the clauses is interpreted by a finite set of ground terms. We consider first-order clauses with the signature restricted to unary predicate and function symbols and one variable. Deciding the existence of a finite Herbrand model for a set of such clauses is known to be ExpTime-hard even when clauses are restricted to an anti-Horn form. Here we present an ExpTime algorithm to decide if a finite Herbrand model exists in the more general case of arbitrary clauses. Moreover, we describe a way to generate finite Herbrand models, if they exist. Since there can be infinitely many minimal finite Herbrand models, we propose a new notion of acyclic Herbrand models. If there is a finite Herbrand model for a set of restricted clauses, then there are finitely many (at most triple-exponentially many) acyclic Herbrand models. We show how to generate all of them.
2

Jeux concurrents enrichis : témoins pour les preuves et les ressources / Enriched concurrent games : witnesses for proofs and resource analysis

Alcolei, Aurore 17 October 2019 (has links)
La sémantique des jeux est une sémantique dénotationnelle centrée sur l’interaction : preuves et programmes y sont représentés par des stratégies modélisant, par le flot d’exécution, leur manière de réagir à leur environnement. Malgré cette présentation intensionnelle, les sémantiques de jeux ne suffisent pas à capturer certaines informations calculatoires annexes au flot d’exécution telles que, par exemple, la production de témoins en logique du premier ordre ou la consommation de ressources dans les langages de programmation. Dans cette thèse nous proposons un enrichissement du modèle des jeux concurrent à base de structures d’événements permettant de garder trace de ces informations.Nous construisons d’abord un modèle de jeux concurrent dans lequel les coups joueurs d’une stratégie sont annotés par les termes d’une théorie (in)équationnelle. Cette théorie est un paramètre de notre modèle et les annotations permettent de refléter de manière compacte des informations d’exécution n’ayant pas d’influence sur le flot d’exécution. Nous montrons que le modèle ainsi construit préserve la structure catégorique compacte fermée du modèle sans annotation.Nous explorons ensuite l’expressivité de notre modèle et présentons deux interprétations nouvelles en sémantique des preuves et des programmes : l’une interprétant les preuves de la logique classique du premier ordre par des stratégies concurrentes avec échange de témoins, donnant une version compositionnelle au théorème de Herbrand ; l’autre permettant de refléter les aspects quantitatifs liés à la consommation de ressources telles que le temps, dans l’exécution de programmes concurrents d’ordre supérieur avec mémoire partagée. / This thesis presents a general framework for enriching causal concurrent games model with annotations. These annotations can be viewed as meta-data on strategies: they are modified throughout interactions but do not affect their general flow of control. These data can be of various nature, in particular our enrichment is parametrised over any multi-sorted equational theory and can also reflect structure upon these data such as a partial order. From a semantics point of view, this construction is motivated by problems from both logic and programming languages: On the logic side, the annotated games model specialised to first-order terms enables us to give a novel interpretation of first-order classical proofs as concurrent strategies carrying first-order witnesses. In particular this answer the question of giving a compositional version to Herbrand’s theorem while avoiding the usual proof sequentialization of other denotational approaches. On the programming language side, annotations on games offer intrinsic quantitative models. We show that those can be used to provide denotational semantics for resource consumption analysis of concurrent higher order programming language with shared memory.These enrichments, strongly connected to the causal structure of concurrent games, give an argument in favor of a causal meaning of computations.
3

Complexity in Statistical Relational Learning : A Study on Learning Bayesian Logic Programs / Komplexitet i statistiskt relationslärande

Hagerf, Alexander January 2015 (has links)
Most work that is done within machine learning today uses statistical methods which assume that the data is identically and independently distributed. However, the problem domains that we face in the real world are often much more complicated and present both complex relational/logical parts as well as parts with uncertainty. Statistical relational learning (SRL) is a sub-field of machine learning and A.I. that tries to solve these limitations by combining both relational and statistical learning and has become a big research sector in recent years. This thesis will present SRL further and specifically introduce, test and review one of the implementations, namely Bayesian logic programs. / Idag används inom maskininlärning nästan alltid statistiska metoder som antar att datat för lärande är identiskt och oberoende distribuerat. Men de problemområden som vi står inför i den verkliga världen är ofta mycket mer komplicerade och har både komplexa relationella/logiska delar samt osäkerhet. Statistiskt relationslärande (SRL) är en del av maskininlärning och A.I. som försöker lösa dessa begränsningar genom att kombinera både relationer och statistiskt lärande och har på senare år blivit ett stort forskningsområde. Denna avhandling presenterar SRL mer i detalj och utreder och testar en specifik implementation, Bayesianska logikprogram.

Page generated in 0.0405 seconds