Academia and industry are investigating novel approaches for processing vast amounts of data coming from enterprises, the Web, social media and sensor readings in an area that has come to be known as Big Data. logic p...
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Academia and industry are investigating novel approaches for processing vast amounts of data coming from enterprises, the Web, social media and sensor readings in an area that has come to be known as Big Data. logicprogramming has traditionally focused on complex knowledge structures/programs. the question arises whether and how it can be applied in the context of Big Data. In this paper, we study how the well-founded semantics can be computed over huge amounts of data using mass parallelization. Specifically, we propose and evaluate a parallel approach based on the X10 programming language. Our experiments demonstrate that our approach has the ability to process up to 1 billion facts within minutes.
In a data exchange setting with target constraints, it is often the case that a given source instance has no solutions. Intuitively, this happens when data sources contain inconsistent or conflicting information that ...
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ISBN:
(纸本)9783319111131;9783319111124
In a data exchange setting with target constraints, it is often the case that a given source instance has no solutions. Intuitively, this happens when data sources contain inconsistent or conflicting information that is exposed by the target constraints at hand. In such cases, the semantics of target queries trivialize, because the certain answers of every target query over the given source instance evaluate to "true". the aim of this paper is to introduce and explore a new framework that gives meaningful semantics in such cases by using the notion of exchange-repairs. Informally, an exchange-repair of a source instance is another source instance that differs minimally from the first, but has a solution. In turn, exchange-repairs give rise to a natural notion of exchange-repair certain answers (in short, XR-certain answers) for target queries in the context of data exchange with target constraints. After exploring the structural properties of exchange-repairs, we focus on the problem of computing the XR-certain answers of conjunctive queries. We show that for schema mappings specified by source-to-target GAV dependencies and target equality-generating dependencies (egds), the XR-certain answers of a target conjunctive query can be rewritten as the consistent answers (in the sense of standard database repairs) of a union of source conjunctive queries over the source schema with respect to a set of egds over the source schema, thus making it possible to use a consistent query-answering system to compute XR-certain answers in data exchange. In contrast, we show that this type of rewriting is not possible for schema mappings specified by source-to-target LAV dependencies and target egds. We then examine the general case of schema mappings specified by source-to-target GLAV constraints, a weakly acyclic set of target tgds and a set of target egds. the main result asserts that, for such settings, the XR-certain answers of conjunctive queries can be rewritten as the certai
Rapid developments of multicore processors in the last ten years have accelerated the advancements in concurrency platforms. Performance of bottom-up resolution algorithms used in logicprogramming and artificial inte...
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ISBN:
(纸本)9781479929719
Rapid developments of multicore processors in the last ten years have accelerated the advancements in concurrency platforms. Performance of bottom-up resolution algorithms used in logicprogramming and artificial intelligent systems, can potentially be improved using the parallel programming constructs offered by these platforms (e.g., OpenMP, Cilk++, etc.). In this work we use cilk++ to implement a parallel bottom-up resolution algorithm, and study how different parallel programming constructs affect its performance. Our experimental results show that a careful cilk++ implementation of the algorithm can lead to significant speedup w.r.t. its traditional serial implementation.
logicprogramming emerged in the 1970s from debates concerning procedural versus declarative representations of knowledge in artificialintelligence. In those days, declarative representations were associated mainly w...
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ISBN:
(纸本)9783642405648
logicprogramming emerged in the 1970s from debates concerning procedural versus declarative representations of knowledge in artificialintelligence. In those days, declarative representations were associated mainly with bottom-up proof procedures, such as hyper-resolution. the development of logicprogramming showed that procedural representations could be obtained by applying top-down proof procedures, such as linear resolution, to declarative representations in logical form. In recent years, logicprogramming has become more purely declarative, withthe development of answer set programming, tabling and the revival of data-log. these recent developments invite comparison with earlier attempts to reconcile procedural and declarative representations of knowledge, and raise the question whether anything has been lost.
Parametrized logic programs are very expressive logic programs that generalize normal logic programs under the stable model semantics, by allowing complex formulas of a parameter logic to appear in the body and head o...
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ISBN:
(纸本)9783642405648
Parametrized logic programs are very expressive logic programs that generalize normal logic programs under the stable model semantics, by allowing complex formulas of a parameter logic to appear in the body and head of rules. In this paper we study the decidability of these rich programs and propose an implementation that combines, in a modular way, a reasoner for the parameter logic with an answer set solver.
In this paper we present a technique based on logicprogramming for data cleaning, and its application to a real use case from the Italian Healthcare System. the use case is part of a more complex project developing a...
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ISBN:
(纸本)9783642405648
In this paper we present a technique based on logicprogramming for data cleaning, and its application to a real use case from the Italian Healthcare System. the use case is part of a more complex project developing a business intelligence suite for the analysis of distributed archives of tumor-based diseases.
Turner's logic of universal causation is a general logic for nonmonotonic reasoning. It has its origin in McCain and Turner's causal action theories which have been translated to propositional logic and logic ...
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ISBN:
(纸本)9783642405648
Turner's logic of universal causation is a general logic for nonmonotonic reasoning. It has its origin in McCain and Turner's causal action theories which have been translated to propositional logic and logicprogramming with nested expressions. In this paper, we propose to do the same for Turner's logic, and show thatTurner's logic can actually be mapped to McCain and Turner's causal theories. these results can be used to construct a system for reasoning in Turner's logic.
In recent work, we provided a formulation of ASP programs in terms of linear logictheories. Based on this work, in this paper we propose and discuss a modified Answer Set Semantics, "Resource-based Answer Set Se...
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ISBN:
(纸本)9783642405648
In recent work, we provided a formulation of ASP programs in terms of linear logictheories. Based on this work, in this paper we propose and discuss a modified Answer Set Semantics, "Resource-based Answer Set Semantics".
We extend the language of here-and-there logic by two kinds of atomic programs allowing to minimally update the truth value of a propositional variable here or there, if possible. these atomic programs are combined by...
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ISBN:
(纸本)9783642405648
We extend the language of here-and-there logic by two kinds of atomic programs allowing to minimally update the truth value of a propositional variable here or there, if possible. these atomic programs are combined by the usual dynamic logic program connectives. We investigate the mathematical properties of the resulting extension of equilibrium logic: we prove that the problem of logical consequence in equilibrium models is EXPTIME complete by relating equilibrium logic to dynamic logic of propositional assignments.
Within everyday reasoning we often use argumentation patterns that employ the rather vague notion of something being normally true. this form of reasoning is usually captured using Reiter's Default logic. However,...
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ISBN:
(纸本)9783642405648
Within everyday reasoning we often use argumentation patterns that employ the rather vague notion of something being normally true. this form of reasoning is usually captured using Reiter's Default logic. However, in Default logic one has to make explicit the rules which are to be used for reasoning and which are supposed to be normally true. this is a bit contrary to the everyday situation where people use experience to decide what normally follows from particular observations and what not, not using any kind of logical rules at all. To formalize this kind of reasoning we propose an approach which is based on prior experiences, using the fact that something follows normally if this is the case for "almost all" of the available experience.
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