312 research outputs found
Updates and Subjunctive Queries
AbstractA subjunctive query of the form φ > ψ, means "if φ were true in the knowledgebase, would ψ also necessarily be true?" We propose the following semantics for subjunctive queries: φ > ψ, will hold in the current knowledgebase T if ψ holds in the result of updating T with φ. This is known as the Ramsey test in philosophy. We adapt the model checking approach of Halpern and Vardi: A knowledgebase is a finite set of finite sets of positive facts interpreted in a closed world setting. We then use Winslett′s possible models approach to give semantics to knowledgebase updates, and we introduce a query language which is essentially propositional logic, augmented with a subjunctive conditional that has an intensional interpretation in our model. We show that query answering and update can be performed in time polynomial in the size of the knowledgebase. However, query equivalence is shown to be complete in polynomial space, and this is also the complexity of query answering as a function of query size. We give a sound axiomatization of query equivalence and show that the update operator satisfies the postulates for updates adapted by Katsuno and Mendelzon from the Alchourrón-Gärdenfors-Makinson belief revision postulates
Consumer Eroski parallel corpus
This paper introduces the Consumer Eroski Parallel Corpus, a collection of articles originally written in Spanish and later translated to three languages also spoken in Spain: Basque, Catalan and Galician. The articles have been correlated in the four languages at the sentence level automatically using Moore's bilingual sentence alignment tool (2002). The Spanish section is also annotated morphosyntactically for parts of speech using SVMtool (Giménez and Márquez 2004). The Basque, Catalan and Galician sections may be annotated in a future release with the collaboration of Computational Linguistics Groups in Spain. To my knowledge, the Consumer Eroski Parallel Corpus is the first resource to exist that encompasses a substantial body of parallel text from these four languages spoken in Spain. I would like to thank the Eroski Foundation for granting permission to share the corpus in the public domain. Making this resource public will provide additional opportunities to test, train and develop natural language processing tools in the computational linguistics community. It may also help translators as a reference. With the addition of an advanced search interface, currently under development, the corpus may be consulted by Basque and Romance linguists interested in cross-linguistic research
Consumer Eroski parallel corpus
This paper introduces the Consumer Eroski Parallel Corpus, a collection of articles originally written in Spanish and later translated to three languages also spoken in Spain: Basque, Catalan and Galician. The articles have been correlated in the four languages at the sentence level automatically using Moore's bilingual sentence alignment tool (2002). The Spanish section is also annotated morphosyntactically for parts of speech using SVMtool (Giménez and Márquez 2004). The Basque, Catalan and Galician sections may be annotated in a future release with the collaboration of Computational Linguistics Groups in Spain. To my knowledge, the Consumer Eroski Parallel Corpus is the first resource to exist that encompasses a substantial body of parallel text from these four languages spoken in Spain. I would like to thank the Eroski Foundation for granting permission to share the corpus in the public domain. Making this resource public will provide additional opportunities to test, train and develop natural language processing tools in the computational linguistics community. It may also help translators as a reference. With the addition of an advanced search interface, currently under development, the corpus may be consulted by Basque and Romance linguists interested in cross-linguistic research
Achilles Heels for AGI/ASI via Decision Theoretic Adversaries
As progress in AI continues to advance, it is crucial to know how advanced
systems will make choices and in what ways they may fail. Machines can already
outsmart humans in some domains, and understanding how to safely build ones
which may have capabilities at or above the human level is of particular
concern. One might suspect that artificially generally intelligent (AGI) and
artificially superintelligent (ASI) systems should be modeled as as something
which humans, by definition, can't reliably outsmart. As a challenge to this
assumption, this paper presents the Achilles Heel hypothesis which states that
even a potentially superintelligent system may nonetheless have stable
decision-theoretic delusions which cause them to make obviously irrational
decisions in adversarial settings. In a survey of relevant dilemmas and
paradoxes from the decision theory literature, a number of these potential
Achilles Heels are discussed in context of this hypothesis. Several novel
contributions are made toward understanding the ways in which these weaknesses
might be implanted into a system.Comment: Contact info for author at stephencasper.co
Machine ethics via logic programming
Machine ethics is an interdisciplinary field of inquiry that emerges from the need of
imbuing autonomous agents with the capacity of moral decision-making. While some
approaches provide implementations in Logic Programming (LP) systems, they have not
exploited LP-based reasoning features that appear essential for moral reasoning.
This PhD thesis aims at investigating further the appropriateness of LP, notably a
combination of LP-based reasoning features, including techniques available in LP systems,
to machine ethics. Moral facets, as studied in moral philosophy and psychology, that
are amenable to computational modeling are identified, and mapped to appropriate LP
concepts for representing and reasoning about them.
The main contributions of the thesis are twofold.
First, novel approaches are proposed for employing tabling in contextual abduction
and updating – individually and combined – plus a LP approach of counterfactual reasoning; the latter being implemented on top of the aforementioned combined abduction and updating technique with tabling. They are all important to model various issues of the aforementioned moral facets.
Second, a variety of LP-based reasoning features are applied to model the identified
moral facets, through moral examples taken off-the-shelf from the morality literature.
These applications include: (1) Modeling moral permissibility according to the Doctrines of Double Effect (DDE) and Triple Effect (DTE), demonstrating deontological and utilitarian judgments via integrity constraints (in abduction) and preferences over abductive scenarios; (2) Modeling moral reasoning under uncertainty of actions, via abduction and probabilistic LP; (3) Modeling moral updating (that allows other – possibly overriding – moral rules to be adopted by an agent, on top of those it currently follows) via the integration of tabling in contextual abduction and updating; and (4) Modeling moral permissibility and its justification via counterfactuals, where counterfactuals are used for formulating DDE.Fundação para a Ciência e a Tecnologia (FCT)-grant SFRH/BD/72795/2010 ; CENTRIA
and DI/FCT/UNL for the supplementary fundin
Reasoning Studies. From Single Norms to Individual Differences.
In review. Submitted for habilitation in psychology
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