We present a logic programming language which uses a four-valued bilattice as the underlying framework for semantics of programs. The two orderings of the bilattice reflect the concepts of truth and knowledge. The space of truth values... more
We present a logic programming language which uses a four-valued bilattice as the underlying framework for semantics of programs. The two orderings of the bilattice reflect the concepts of truth and knowledge. The space of truth values includes not only true and false, but also other truth values which represent no information or conflicting information. Programs are interpreted according to
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A counting finite-state automaton is a nondeterministic finite-state automaton which, on an input over its input alphabet, (magically) writes in binary the number of accepting computations on the input. We examine the complexity of... more
A counting finite-state automaton is a nondeterministic finite-state automaton which, on an input over its input alphabet, (magically) writes in binary the number of accepting computations on the input. We examine the complexity of computing the counting function of an NFA, and the complexity of recognizing its range as a set of binary strings. We also consider the pumping behavior
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We present an algorithm for searching a 2D environ-ment for unpredictable moving targets using only beam-based detection. One or more pursuers move along the environment boundary, and carry a rotating beam that detects evaders. The beam... more
We present an algorithm for searching a 2D environ-ment for unpredictable moving targets using only beam-based detection. One or more pursuers move along the environment boundary, and carry a rotating beam that detects evaders. The beam could correspond in prac-tice to a ...
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... They presented a pursuit-evasion algorithm in which the searcher does not have a map of the polygon. ... sider a single connected (white) region in W . If we traverse its boundary and follow the projections on the horizontal and... more
... They presented a pursuit-evasion algorithm in which the searcher does not have a map of the polygon. ... sider a single connected (white) region in W . If we traverse its boundary and follow the projections on the horizontal and vertical axes, we observe that the local extremums of ...
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A counting finite-state automaton is a nondeterministic finite-state au- tomaton which, on an input over its input alphabet, (magically) writes in binary the number of accepting computations on the input. We examine the complexity of... more
A counting finite-state automaton is a nondeterministic finite-state au- tomaton which, on an input over its input alphabet, (magically) writes in binary the number of accepting computations on the input. We examine the complexity of comput- ing the counting function of an NFA, and the complexity of recognizing its range as a set of binary strings. We also consider the
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We consider optimization problems on weighted graphs where vertex andedge weights are polynomial functions of a parameter . We show that, if aproblem satisfies certain regularity properties and the underlying graph hasbounded tree-width,... more
We consider optimization problems on weighted graphs where vertex andedge weights are polynomial functions of a parameter . We show that, if aproblem satisfies certain regularity properties and the underlying graph hasbounded tree-width, the number of changes in the optimum solution is polynomiallybounded. We also show that the description of the sequence of optimumsolutions can be constructed in polynomial time
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Bounds are given on the size of the parameter-space decomposition induced by multiple sequence alignment problems where phylogenetic information may be given or inferred. It is shown that many of the usual formulations of these problems... more
Bounds are given on the size of the parameter-space decomposition induced by multiple sequence alignment problems where phylogenetic information may be given or inferred. It is shown that many of the usual formulations of these problems fall within the same integer parametric framework, implying that the number of distinct optima obtained as the parameters are varied across their ranges is
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Abstract We consider optimization problems on weighted trees, including weighted versions of the minimum vertex cover and the minimum dominating set problems, where vertex and edge weights vary as linear functions of time. For each of the... more
Abstract We consider optimization problems on weighted trees, including weighted versions of the minimum vertex cover and the minimum dominating set problems, where vertex and edge weights vary as linear functions of time. For each of the problems studied here, we ...
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An optimizing finite-state transducer is a nondeterministic finite-state transducer in which states are either maximizing or minimizing. In a given state, the optimal out- put is the maximum or minimum—over all possible transitions—of the... more
An optimizing finite-state transducer is a nondeterministic finite-state transducer in which states are either maximizing or minimizing. In a given state, the optimal out- put is the maximum or minimum—over all possible transitions—of the transition output concatenated with the optimal output of the resulting state. The ranges of optimizing finite-state transducers form a class in NL which includes a hierarchy
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Consider a set of elements which we want to rate using information about their bilateral relationships. For instance sports teams and the outcomes of their games, journals and their mutual citations, web sites and their link structure, or... more
Consider a set of elements which we want to rate using information about their bilateral relationships. For instance sports teams and the outcomes of their games, journals and their mutual citations, web sites and their link structure, or social alternatives and the tournament derived from the voters' preferences. A wide variety of scoring methods have been proposed to deal with
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... Abstract. A relationship between parallel rewriting systems and two-way machines is investigated. Restrictions on the copying power of these devices endow them with rich structuring and give insight into the issues of determinism,... more
... Abstract. A relationship between parallel rewriting systems and two-way machines is investigated. Restrictions on the copying power of these devices endow them with rich structuring and give insight into the issues of determinism, parallelism, and copying. ...
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ABSTRACT We present algorithms for the perfect phylogeny problem restricted to binary characters. The first algorithm is faster than a previous algorithm by Gusfield when the input matrix for the problem is sparse. Next, we present two... more
ABSTRACT We present algorithms for the perfect phylogeny problem restricted to binary characters. The first algorithm is faster than a previous algorithm by Gusfield when the input matrix for the problem is sparse. Next, we present two online algorithms. For the first of these, the set of species is fixed and the characters are given as input one at a time, while, for the second, the set of characters is fixed and the species are given as input one at a time. These two online algorithms are then combined into an algorithm that can process any ...
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Abstract. Many semantic web applications require support for knowledge representation and inference over a federation of multiple autonomous ontology modules, without having to combine them in one location. Federated ALCI or F-ALCI is a... more
Abstract. Many semantic web applications require support for knowledge representation and inference over a federation of multiple autonomous ontology modules, without having to combine them in one location. Federated ALCI or F-ALCI is a modular description logic, each of whose modules is roughly an ALCI ontology (ALC with inverse roles). FALCI supports importing of both concepts and roles across modules as well as contextualized interpretation of logical connectives. We present a federated tableau algorithm for ...
Abstract. Many semantic web applications require selective sharing of ontologies between autonomous entities due to copyright, privacy or security concerns. In our previous work it was shown that, on such occasions, an agent who wishes to... more
Abstract. Many semantic web applications require selective sharing of ontologies between autonomous entities due to copyright, privacy or security concerns. In our previous work it was shown that, on such occasions, an agent who wishes to hide part of its ontology while sharing the rest may still be able to answer safely queries against its knowledge base using inferences based on both hidden and visible knowledge without revealing the hidden knowledge. Moreover, it was shown how this framework may be applied to the case of ...
We present the syntax and semantics of a modular ontology language SHOIQP to support context-specific reuse of knowledge from multiple ontologies. A SHOIQP ontology consists of multiple ontology modules (each of which can be viewed as a... more
We present the syntax and semantics of a modular ontology language SHOIQP to support context-specific reuse of knowledge from multiple ontologies. A SHOIQP ontology consists of multiple ontology modules (each of which can be viewed as a SHOIQ ontology) and concept, role and nominal names can be shared by “importing” relations among modules. SHOIQP supports contextualized interpretation, ie, interpretation from the point of view of a specific package. We establish the necessary and sufficient constraints on ...