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61
A Scheme for Integrating Concrete Domains into Concept Languages
, 1991
"... A drawback which concept languages based on klone have is that all the terminological knowledge has to be defined on an abstract logical level. In many applications, one would like to be able to refer to concrete domains and predicates on these domains when defining concepts. Examples for such conc ..."
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Cited by 262 (20 self)
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A drawback which concept languages based on klone have is that all the terminological knowledge has to be defined on an abstract logical level. In many applications, one would like to be able to refer to concrete domains and predicates on these domains when defining concepts. Examples for such concrete domains are the integers, the real numbers, or also nonarithmetic domains, and predicates could be equality, inequality, or more complex predicates. In the present paper we shall propose a scheme for integrating such concrete domains into concept languages rather than describing a particular extension by some specific concrete domain. We shall define a terminological and an assertional language, and consider the important inference problems such as subsumption, instantiation, and consistency. The formal semantics as well as the reasoning algorithms are given on the scheme level. In contrast to existing klone based systems, these algorithms will be not only sound but also complete. The...
A Survey of Computational Complexity Results in Systems and Control
, 2000
"... The purpose of this paper is twofold: (a) to provide a tutorial introduction to some key concepts from the theory of computational complexity, highlighting their relevance to systems and control theory, and (b) to survey the relatively recent research activity lying at the interface between these fi ..."
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Cited by 116 (21 self)
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The purpose of this paper is twofold: (a) to provide a tutorial introduction to some key concepts from the theory of computational complexity, highlighting their relevance to systems and control theory, and (b) to survey the relatively recent research activity lying at the interface between these fields. We begin with a brief introduction to models of computation, the concepts of undecidability, polynomial time algorithms, NPcompleteness, and the implications of intractability results. We then survey a number of problems that arise in systems and control theory, some of them classical, some of them related to current research. We discuss them from the point of view of computational complexity and also point out many open problems. In particular, we consider problems related to stability or stabilizability of linear systems with parametric uncertainty, robust control, timevarying linear systems, nonlinear and hybrid systems, and stochastic optimal control.
Equations and rewrite rules: a survey
 In Formal Language Theory: Perspectives and Open Problems
, 1980
"... bY ..."
Schema Equivalence in Heterogeneous Systems: Bridging Theory and Practice
, 1993
"... Current theoretical work offers measures of schema equivalence based on the information capacity of schemas. This work is based on the existence of abstract functions satisfying various restrictions between the sets of all instances of two schemas. In considering schemas that arise in practice, howe ..."
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Cited by 62 (2 self)
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Current theoretical work offers measures of schema equivalence based on the information capacity of schemas. This work is based on the existence of abstract functions satisfying various restrictions between the sets of all instances of two schemas. In considering schemas that arise in practice, however, it is not clear how to reason about the existence of such abstract functions. Further, these notions of equivalence tend to be too liberal in that schemas are often considered equivalent when a practitioner would consider them to be different. As a result, practical integration methodologies have not utilized this theoretical foundation and most of them have relied on adhoc approaches. We present results that seek to bridge this gap. First, we consider the problem of deciding information capacity equivalence and dominance of schemas that occur in practice, i.e., those that can express inheritance and simple integrity constraints. We show that this problem is undecidable. This undecidab...
Informationtheoretic Limitations of Formal Systems
 JOURNAL OF THE ACM
, 1974
"... An attempt is made to apply informationtheoretic computational complexity to metamathematics. The paper studies the number of bits of instructions that must be a given to a computer for it to perform finite and infinite tasks, and also the amount of time that it takes the computer to perform these ..."
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Cited by 45 (7 self)
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An attempt is made to apply informationtheoretic computational complexity to metamathematics. The paper studies the number of bits of instructions that must be a given to a computer for it to perform finite and infinite tasks, and also the amount of time that it takes the computer to perform these tasks. This is applied to measuring the difficulty of proving a given set of theorems, in terms of the number of bits of axioms that are assumed, and the size of the proofs needed to deduce the theorems from the axioms.
The Ring of kRegular Sequences
, 1992
"... The automatic sequence is the central concept at the intersection of formal language theory and number theory. It was introduced by Cobham, and has been extensively studied by Christol, Kamae, Mendes France and Rauzy, and other writers. Since the range of automatic sequences is nite, however, their ..."
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Cited by 39 (7 self)
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The automatic sequence is the central concept at the intersection of formal language theory and number theory. It was introduced by Cobham, and has been extensively studied by Christol, Kamae, Mendes France and Rauzy, and other writers. Since the range of automatic sequences is nite, however, their descriptive power is severely limited.
The Convenience of Tilings
 In Complexity, Logic, and Recursion Theory
, 1997
"... Tiling problems provide for a very simple and transparent mechanism for encoding machine computations. This gives rise to rather simple master reductions showing various versions of the tiling problem complete for various complexity classes. We investigate the potential for using these tiling proble ..."
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Cited by 36 (0 self)
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Tiling problems provide for a very simple and transparent mechanism for encoding machine computations. This gives rise to rather simple master reductions showing various versions of the tiling problem complete for various complexity classes. We investigate the potential for using these tiling problems in subsequent reductions showing hardness of the combinatorial problems that really matter. We ilustrate our approach by means of three examples: a short reduction chain to the Knapsack problem followed by a Hilbert 10 reduction using similar ingredients. Finally we reprove the Deterministic Exponential Time lowerbound for satisfiablility in Propositional Dynamic Logic. The resulting reductions are relatively simple; they do however infringe on the principle of orthogonality of reductions since they abuse extra structure in the instances of the problems reduced from which results from the fact that these instances were generated by a master reduction previously. 1 Introduction This paper...
Description Logics with Concrete Domains and Aggregation
, 1998
"... We extend different Description Logics by concrete domains (such as integers and reals) and by aggregation functions over these domains (such as min; max; count; sum), which are usually available in database systems. On the one hand, we show that this extension may lead to undecidability of the basi ..."
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Cited by 29 (5 self)
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We extend different Description Logics by concrete domains (such as integers and reals) and by aggregation functions over these domains (such as min; max; count; sum), which are usually available in database systems. On the one hand, we show that this extension may lead to undecidability of the basic inference problems satisfiability and subsumption. This is true even for a very small Description Logic and very simple aggregation functions, provided that universal value restrictions are present. On the other hand, disallowing universal value restrictions yields decidability of satisfiability, provided that the concrete domain is not too expressive. An example of such a concrete domain is the set of (nonnegative) integers with comparisons (=, #, #n , ...) and the aggregation functions min; max; count.
On Diophantine Complexity and Statistical ZeroKnowledge Arguments
 Advances on Cryptology — ASIACRYPT 2003
, 2003
"... Abstract. We show how to construct practical honestverifier statistical zeroknowledge Diophantine arguments of knowledge (HVSZK AoK) that a committed tuple of integers belongs to an arbitrary language in bounded arithmetic. While doing this, we propose a new algorithm for computing the Lagrange re ..."
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Cited by 28 (6 self)
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Abstract. We show how to construct practical honestverifier statistical zeroknowledge Diophantine arguments of knowledge (HVSZK AoK) that a committed tuple of integers belongs to an arbitrary language in bounded arithmetic. While doing this, we propose a new algorithm for computing the Lagrange representation of nonnegative integers and a new efficient representing polynomial for the exponential relation. We apply our results by constructing the most efficient known HVSZK AoK for nonnegativity and the first constantround practical HVSZK AoK for exponential relation. Finally, we propose the outsourcing model for cryptographic protocols and design communicationefficient versions of the Damg˚ardJurik multicandidate voting scheme and of the LipmaaAsokanNiemi (b + 1)stprice auction scheme that work in this model.