http://sedici.unlp.edu.ar:80/handle/10915/182983 Thu, 12 Nov 2026 21:14:11 GMT 2026-11-12T21:14:11Z http://sedici.unlp.edu.ar:80/handle/10915/185588 Objeto de conferencia Argentine Workshop on Theoretical Computer Science (WAIT 2002) - JAIIO 31 (Santa Fe, 9 al 13 de septiembre de 2002) We present a deformation technique which allows us to determine the number of real solutions of certain specific polynomial equation system. We apply this deformation technique in order to determine the number of stationary solutions of the semidiscretization of certain parabolic differential equations. Tue, 01 Jan 2002 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/185588 2002-01-01T00:00:00Z We present a deformation technique which allows us to determine the number of real solutions of certain specific polynomial equation system. We apply this deformation technique in order to determine the number of stationary solutions of the semidiscretization of certain parabolic differential equations. http://sedici.unlp.edu.ar:80/handle/10915/183655 Objeto de conferencia Argentine Workshop on Theoretical Computer Science (WAIT 2002) - JAIIO 31 (Santa Fe, 9 al 13 de septiembre de 2002) This article describes strategies devised to improve the efficiency of two classical index data structures for parallel textual databases. The design and cost evaluation is effected on top of the bulk-synchronous model of parallel computing. This allows us to compare different alternatives under the same framework in a way which is independent of programming details and architecture of the parallel machine. Our interest is on query processing upon cluster of PCs, and thereby we focus on communication and synchronization optimization. Tue, 01 Jan 2002 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/183655 2002-01-01T00:00:00Z This article describes strategies devised to improve the efficiency of two classical index data structures for parallel textual databases. The design and cost evaluation is effected on top of the bulk-synchronous model of parallel computing. This allows us to compare different alternatives under the same framework in a way which is independent of programming details and architecture of the parallel machine. Our interest is on query processing upon cluster of PCs, and thereby we focus on communication and synchronization optimization. http://sedici.unlp.edu.ar:80/handle/10915/183654 Objeto de conferencia Argentine Workshop on Theoretical Computer Science (WAIT 2002) - JAIIO 31 (Santa Fe, 9 al 13 de septiembre de 2002) Based on the Calculus of Constructions extended with inductive de nitions we present a Theory of Speci fications with rules for simultaneously constructing programs and their correctness proofs. The theory contains types for representing speci fications, whose corresponding notion of implementation is that of a pair formed by a program and a correctness proof. The rules of the theory are such that in implementations the program parts appear mixed together with the proof parts. A reduction relation performs the task of separating programs from proofs. Consequently, every implementation computes to a pair composed of a program and a proof of its correctness, and so the program extraction procedure is immediate. Tue, 01 Jan 2002 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/183654 2002-01-01T00:00:00Z Based on the Calculus of Constructions extended with inductive de nitions we present a Theory of Speci fications with rules for simultaneously constructing programs and their correctness proofs. The theory contains types for representing speci fications, whose corresponding notion of implementation is that of a pair formed by a program and a correctness proof. The rules of the theory are such that in implementations the program parts appear mixed together with the proof parts. A reduction relation performs the task of separating programs from proofs. Consequently, every implementation computes to a pair composed of a program and a proof of its correctness, and so the program extraction procedure is immediate. http://sedici.unlp.edu.ar:80/handle/10915/183652 Objeto de conferencia Argentine Workshop on Theoretical Computer Science (WAIT 2002) - JAIIO 31 (Santa Fe, 9 al 13 de septiembre de 2002) A resultant is a polynomial representing a quantifier–free primitive formula which is equivalent to a suitable prenex formula in the existential theory of algebraically closed fields of given characteristic. A resultant expresses a flatness condition about the parametric polynomial equation system under consideration. Tue, 01 Jan 2002 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/183652 2002-01-01T00:00:00Z A resultant is a polynomial representing a quantifier–free primitive formula which is equivalent to a suitable prenex formula in the existential theory of algebraically closed fields of given characteristic. A resultant expresses a flatness condition about the parametric polynomial equation system under consideration. http://sedici.unlp.edu.ar:80/handle/10915/183650 Objeto de conferencia Argentine Workshop on Theoretical Computer Science (WAIT 2002) - JAIIO 31 (Santa Fe, 9 al 13 de septiembre de 2002) Parallel composition with observers is a well-known approach to check or test properties over formal models of concurrent and real-time systems. We present a new technique to reduce the size of the resulting model. Tue, 01 Jan 2002 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/183650 2002-01-01T00:00:00Z Parallel composition with observers is a well-known approach to check or test properties over formal models of concurrent and real-time systems. We present a new technique to reduce the size of the resulting model. http://sedici.unlp.edu.ar:80/handle/10915/183649 Objeto de conferencia Argentine Workshop on Theoretical Computer Science (WAIT 2002) - JAIIO 31 (Santa Fe, 9 al 13 de septiembre de 2002) We study perpetual rewrite strategies (strategies that preserve the possibility of in finite derivations) in the λws-calculus, a lambda calculus with explicit substitutions allowing the composition of substitutions. Since current literature on perpetuality is not applicable to λws we exploit a proof technique for proving preservation of strong normalization of calculi of explicit substitutions. We de fine a perpetual rewrite strategy for λws and formulate an inductive characterization of the set of strongly λws-normalizing terms. Tue, 01 Jan 2002 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/183649 2002-01-01T00:00:00Z We study perpetual rewrite strategies (strategies that preserve the possibility of in finite derivations) in the λws-calculus, a lambda calculus with explicit substitutions allowing the composition of substitutions. Since current literature on perpetuality is not applicable to λws we exploit a proof technique for proving preservation of strong normalization of calculi of explicit substitutions. We de fine a perpetual rewrite strategy for λws and formulate an inductive characterization of the set of strongly λws-normalizing terms. http://sedici.unlp.edu.ar:80/handle/10915/183647 Objeto de conferencia Argentine Workshop on Theoretical Computer Science (WAIT 2002) - JAIIO 31 (Santa Fe, 9 al 13 de septiembre de 2002) We show explicit estimates for the number of q{rational points of an Fq {de finable affine variety of F n q . Our estimates improve previous estimates in [46], [47] and [12]. Our proofs rely on elementary methods of effective elimination theory. Tue, 01 Jan 2002 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/183647 2002-01-01T00:00:00Z We show explicit estimates for the number of q{rational points of an Fq {de finable affine variety of F n q . Our estimates improve previous estimates in [46], [47] and [12]. Our proofs rely on elementary methods of effective elimination theory. http://sedici.unlp.edu.ar:80/handle/10915/183645 Objeto de conferencia Argentine Workshop on Theoretical Computer Science (WAIT 2002) - JAIIO 31 (Santa Fe, 9 al 13 de septiembre de 2002) In this paper we consider two location problems related to the location of obnoxious facilities in a network, i.e., of facilities that give some sort of disturbe to the users of the facilities. Research on this subject is relatively recent and good methods and models are still to be provided. Tue, 01 Jan 2002 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/183645 2002-01-01T00:00:00Z In this paper we consider two location problems related to the location of obnoxious facilities in a network, i.e., of facilities that give some sort of disturbe to the users of the facilities. Research on this subject is relatively recent and good methods and models are still to be provided.