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Behavior Protocols for Software Components
 IEEE Transactions on Software Engineering
, 2002
"... In this paper, we propose a means to enhance an architecture description language with a description of component behavior. A notation used for this purpose should be able to express the "interplay" on the component's interfaces and reflect stepbystep refinement of the component& ..."
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Cited by 186 (32 self)
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In this paper, we propose a means to enhance an architecture description language with a description of component behavior. A notation used for this purpose should be able to express the "interplay" on the component's interfaces and reflect stepbystep refinement of the component's specification during its design. In addition, the notation should be easy to comprehend and allow for formal reasoning about the correctness of the specification refinement and also about the correctness of an implementation in terms of whether it adheres to the specification. Targeting all these requirements together, the paper proposes to employ behaviorprotocols which are based on a notation similar to regular expressions.
Regular Expression Types for XML
, 2003
"... We propose regular expression types as a foundation for statically typed XML processing languages. Regular expression types, like most schema languages for XML, introduce regular expression notations such as repetition (*), alternation (), etc., to describe XML documents. The novelty of our type sy ..."
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Cited by 185 (20 self)
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We propose regular expression types as a foundation for statically typed XML processing languages. Regular expression types, like most schema languages for XML, introduce regular expression notations such as repetition (*), alternation (), etc., to describe XML documents. The novelty of our type system is a semantic presentation of subtyping, as inclusion between the sets of documents denoted by two types. We give several examples illustrating the usefulness of this form of subtyping in XML processing. The decision problem for the subtype relation reduces to the inclusion problem between tree automata, which is known to be exptimecomplete. To avoid this high complexity in typical cases, we develop a practical algorithm that, unlike classical algorithms based on determinization of tree automata, checks the inclusion relation by a topdown traversal of the original type expressions. The main advantage of this algorithm is that it can exploit the property that type expressions being compared often share portions of their representations. Our algorithm is a variant of Aiken and Murphy’s setinclusion constraint solver, to which are added several new implementation techniques, correctness proofs, and preliminary performance measurements on some small programs in the domain of typed XML processing.
Precise analysis of string expressions
 In Proc. 10th International Static Analysis Symposium, SAS ’03, volume 2694 of LNCS
, 2003
"... We perform static analysis of Java programs to answer a simple question: which values may occur as results of string expressions? The answers are summarized for each expression by a regular language that is guaranteed to contain all possible values. We present several applications of this analysis, ..."
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Cited by 175 (17 self)
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We perform static analysis of Java programs to answer a simple question: which values may occur as results of string expressions? The answers are summarized for each expression by a regular language that is guaranteed to contain all possible values. We present several applications of this analysis, including statically checking the syntax of dynamically generated expressions, such as SQL queries. Our analysis constructs flow graphs from class files and generates a contextfree grammar with a nonterminal for each string expression. The language of this grammar is then widened into a regular language through a variant of an algorithm previously used for speech recognition. The collection of resulting regular languages is compactly represented as a special kind of multilevel automaton from which individual answers may be extracted. If a program error is detected, examples of invalid strings are automatically produced. We present extensive benchmarks demonstrating that the analysis is e#cient and produces results of useful precision.
Identification of protein coding regions by database similarity search
 Nature Genetics
, 1993
"... Correspondence should be addressed to W.G. page 1 Summary Sequence similarity between a translated nucleotide sequence and a known biological protein can provide strong evidence for the presence of a homologous coding region, and such similarities can often be identified even between distantly relat ..."
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Cited by 168 (1 self)
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Correspondence should be addressed to W.G. page 1 Summary Sequence similarity between a translated nucleotide sequence and a known biological protein can provide strong evidence for the presence of a homologous coding region, and such similarities can often be identified even between distantly related genes. The computer program BLASTX performed conceptual translation of a nucleotide query sequence followed by a protein database search in one programmatic step. The BLAST search algorithm combined with KarlinAltschul statistics yields a predictable selectivity that has been parameterized. We characterized the sensitivity of BLASTX recognition to the presence of substitution, insertion and deletion errors in the query sequence and to sequence divergence. Reading frames were reliably identified in the presence of 1 % query errors, a rate that is typical for primary nucleotide sequence data. BLASTX is appropriate for use in moderate and large scale sequencing projects at the earliest opportunity, when the data are most prone to containing errors. page 2
Finite Automata Play the Repeated Prisoner's Dilemma
 Journal of Economic Theory
, 1986
"... The paper studies twoperson supergames. Each player is restricted to carry out his strategies by finite automata. A player’s aim is to maximize his average payoff and subject to that, to minimize the number of states of his machine. A solution is defined as a pair of machines in which the choice of ..."
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Cited by 165 (5 self)
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The paper studies twoperson supergames. Each player is restricted to carry out his strategies by finite automata. A player’s aim is to maximize his average payoff and subject to that, to minimize the number of states of his machine. A solution is defined as a pair of machines in which the choice of machine is optimal for each player at every stage of the game. Several properties of the solution are studied and are applied to the repeated prisoner’s dilemma. In particular it is shown that cooperation cannot be the outcome of a solution of the infinitely repeated prisoner’s
On The Computational Power Of Neural Nets
 JOURNAL OF COMPUTER AND SYSTEM SCIENCES
, 1995
"... This paper deals with finite size networks which consist of interconnections of synchronously evolving processors. Each processor updates its state by applying a "sigmoidal" function to a linear combination of the previous states of all units. We prove that one may simulate all Turing Mach ..."
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Cited by 162 (22 self)
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This paper deals with finite size networks which consist of interconnections of synchronously evolving processors. Each processor updates its state by applying a "sigmoidal" function to a linear combination of the previous states of all units. We prove that one may simulate all Turing Machines by such nets. In particular, one can simulate any multistack Turing Machine in real time, and there is a net made up of 886 processors which computes a universal partialrecursive function. Products (high order nets) are not required, contrary to what had been stated in the literature. Nondeterministic Turing Machines can be simulated by nondeterministic rational nets, also in real time. The simulation result has many consequences regarding the decidability, or more generally the complexity, of questions about recursive nets.
Path Sharing and Predicate Evaluation for HighPerformance XML Filtering
 ACM TRANS. DATABASE SYST
, 2003
"... ... In this paper we first describe the XFilter and YFilter approaches and present results of a detailed performance comparison of structure matching for these algorithms as well as a hybrid approach. The results show that the path sharing employed by YFilter can provide orderofmagnitude performan ..."
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Cited by 160 (6 self)
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... In this paper we first describe the XFilter and YFilter approaches and present results of a detailed performance comparison of structure matching for these algorithms as well as a hybrid approach. The results show that the path sharing employed by YFilter can provide orderofmagnitude performance benefits. We then propose two alternative techniques for extending YFilter's shared structure matching with support for valuebased predicates, and compare the performance of these two techniques. The results of this latter study demonstrate some key differences between shared XML filtering and traditional database query processing. Finally, we describe how the YFilter approach is extended to handle more complicated queries containing nested path expressions.
Fast Regular Expression Matching using FPGAs
, 2001
"... This paper presents an efficient method for finding matches to a given regular expression in given text using FPGAs. To match a regular expression of length n, a serial machine requires O(2 ) memory and takes O(1) time per text character. The proposed approach requires only O(n 2) space and still pr ..."
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Cited by 158 (15 self)
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This paper presents an efficient method for finding matches to a given regular expression in given text using FPGAs. To match a regular expression of length n, a serial machine requires O(2 ) memory and takes O(1) time per text character. The proposed approach requires only O(n 2) space and still processes a text character in O(1) time (one clock cycle). The improvement is due to the Nondeterministic Finite Automaton (NFA) used to perform the matching. As far as the authors are aware, this is the fnst practical use of a nondeterministic state machine on programmable logic.
Weighted finitestate transducers in speech recognition
 COMPUTER SPEECH & LANGUAGE
, 2002
"... We survey the use of weighted finitestate transducers (WFSTs) in speech recognition. We show that WFSTs provide a common and natural representation for hidden Markov models (HMMs), contextdependency, pronunciation dictionaries, grammars, and alternative recognition outputs. Furthermore, general tr ..."
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Cited by 157 (4 self)
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We survey the use of weighted finitestate transducers (WFSTs) in speech recognition. We show that WFSTs provide a common and natural representation for hidden Markov models (HMMs), contextdependency, pronunciation dictionaries, grammars, and alternative recognition outputs. Furthermore, general transducer operations combine these representations flexibly and efficiently. Weighted determinization and minimization algorithms optimize their time and space requirements, and a weight pushing algorithm distributes the weights along the paths of a weighted transducer optimally for speech recognition. As an example, we describe a North American Business News (NAB) recognition system built using these techniques that combines the HMMs, full crossword triphones, a lexicon of 40 000 words, and a large trigram grammar into a single weighted transducer that is only somewhat larger than the trigram word grammar and that runs NAB in realtime on a very simple decoder. In another example, we show that the same techniques can be used to optimize lattices for secondpass recognition. In a third example, we show how general automata operations can be used to assemble lattices from different recognizers to improve recognition performance.