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98
Skip Graphs
 Proc. of the 14th Annual ACMSIAM Symp. on Discrete Algorithms
, 2003
"... Skip graphs are a novel distributed data structure, based on skip lists, that provide the full functionality of a balanced tree in a distributed system where resources are stored in separate nodes that may fail at any time. They are designed for use in searching peertopeer systems, and by providin ..."
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Cited by 271 (9 self)
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Skip graphs are a novel distributed data structure, based on skip lists, that provide the full functionality of a balanced tree in a distributed system where resources are stored in separate nodes that may fail at any time. They are designed for use in searching peertopeer systems, and by providing the ability to perform queries based on key ordering, they improve on existing search tools that provide only hash table functionality. Unlike skip lists or other tree data structures, skip graphs are highly resilient, tolerating a large fraction of failed nodes without losing connectivity. In addition, constructing, inserting new nodes into, searching a skip graph, and detecting and repairing errors in the data structure introduced by node failures can be done using simple and straightforward algorithms. 1
Interprocedural MayAlias Analysis for Pointers: Beyond klimiting
, 1994
"... Existing methods for alias analysis of recursive pointer data structures are based on two approximation techniques: klimiting, which blurs distinction between subobjects below depth k; and storebased (or equivalently location or regionbased) approximations, which blur distinction between elements ..."
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Cited by 239 (0 self)
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Existing methods for alias analysis of recursive pointer data structures are based on two approximation techniques: klimiting, which blurs distinction between subobjects below depth k; and storebased (or equivalently location or regionbased) approximations, which blur distinction between elements of recursive data structures. Although notable progress in interprocedural alias analysis has been recently accomplished, very little progress in the precision of analysis of recursive pointer data structures has been seen since the inception of these approximation techniques by Jones and Muchnick a decade ago. As a result, optimizing, verifying and parallelizing programs with pointers has remained difficult. We present a new parametric framework for analyzing recursive pointer data structures which can express a new natural class of alias information not accessib...
Supervisory control of concurrent discreteevent systems
 International Journal of Control
, 1991
"... When a discreteevent system P consists of several subsystems P1,..., Pn that operate concurrently, a natural approach to the supervisory control problem is to synthesize a ’local ’ controller Si for each subsystem Pi and operate the individually controlled subsystems Si/Pi concurrently. Such an a ..."
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Cited by 44 (0 self)
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When a discreteevent system P consists of several subsystems P1,..., Pn that operate concurrently, a natural approach to the supervisory control problem is to synthesize a ’local ’ controller Si for each subsystem Pi and operate the individually controlled subsystems Si/Pi concurrently. Such an approach is called concurrent supervisory control and is closely related to decentralized supervisory control as studied in [4] and [5]. In the present paper simple and easily computable conditions are developed, that guarantee when concurrent supervisory control can achieve the optimal behavior achievable by a global supervisor. To achieve the optimal behavior, two specific concurrent control strategies are introduced. Key words: discrete event systems, supervisory control, concurrency, decentralization, separability. 1
Modeling and Analysis of Timed Petri Nets Using Heaps of Pieces
, 1997
"... We show that safe timed Petri nets can be represented by special automata over the (max,+) semiring, which compute the height of heaps of pieces. This extends to the timed case the classical representation a la Mazurkievicz of the behavior of safe Petri nets by trace monoids and trace languages. Fo ..."
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Cited by 44 (16 self)
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We show that safe timed Petri nets can be represented by special automata over the (max,+) semiring, which compute the height of heaps of pieces. This extends to the timed case the classical representation a la Mazurkievicz of the behavior of safe Petri nets by trace monoids and trace languages. For a subclass including all safe Free Choice Petri nets, we obtain reduced heap realizations using structural properties of the net (covering by safe state machine components). We illustrate the heapbased modeling by the typical case of safe jobshops. For a periodic schedule, we obtain a heapbased throughput formula, which is simpler to compute than its traditional timed event graph version, particularly if one is interested in the successive evaluation of a large number of possible schedules. Keywords Timed Petri nets, automata with multiplicities, heaps of pieces, (max,+) semiring, scheduling. I. Introduction The purpose of this paper 1 is to prove the following result: Timed safe Pe...
Weighted automata and weighted logics
 In Automata, Languages and Programming – 32nd International Colloquium, ICALP 2005
, 2005
"... Abstract. Weighted automata are used to describe quantitative properties in various areas such as probabilistic systems, image compression, speechtotext processing. The behaviour of such an automaton is a mapping, called a formal power series, assigning to each word a weight in some semiring. We g ..."
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Cited by 41 (7 self)
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Abstract. Weighted automata are used to describe quantitative properties in various areas such as probabilistic systems, image compression, speechtotext processing. The behaviour of such an automaton is a mapping, called a formal power series, assigning to each word a weight in some semiring. We generalize Büchi’s and Elgot’s fundamental theorems to this quantitative setting. We introduce a weighted version of MSO logic and prove that, for commutative semirings, the behaviours of weighted automata are precisely the formal power series definable with our weighted logic. We also consider weighted firstorder logic and show that aperiodic series coincide with the firstorder definable ones, if the semiring is locally finite, commutative and has some aperiodicity property. 1
Minor Identities For QuasiDeterminants And Quantum Determinants
 COMM. MATH. PHYS
, 1994
"... We present several identities involving quasiminors of noncommutative generic matrices. These identities are specialized to quantum matrices, yielding qanalogues of various classical determinantal formulas. ..."
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Cited by 40 (4 self)
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We present several identities involving quasiminors of noncommutative generic matrices. These identities are specialized to quantum matrices, yielding qanalogues of various classical determinantal formulas.
Mapping between Dissimilar Bodies: Affordances and the Algebraic Foundations of Imitation
, 1998
"... A fundamental problem for imitation is to create an appropriate (partial) mapping between the body of the system being imitated and the imitator. By considering for each of these two systems an associated automata (resp. transformation semigroup) structure, attempts at such mapping can be considered ..."
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Cited by 35 (12 self)
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A fundamental problem for imitation is to create an appropriate (partial) mapping between the body of the system being imitated and the imitator. By considering for each of these two systems an associated automata (resp. transformation semigroup) structure, attempts at such mapping can be considered relational homomorphisms. This paper shows how mathematical techniques can then be applied to characterize how far such a relation is from a successful imitation. For the imitator and the imitated, affordances in the agentenvironment structural coupling are likely to be different, all the more in the case of dissimilar embodiment. We argue that the use of what is afforded to the imitator to attain corresponding effects or, as in dance, sequences of effects, is necessary and sufficient for successful imitation. Moreover, the judged degree of success or failure of an imitation depends on some externally imposed or  in the case of automonous agents  internally determined criteria on eff...
Learning Functions Represented as Multiplicity Automata
, 2000
"... We study the learnability of multiplicity automata in Angluin’s exact learning model, and we investigate its applications. Our starting point is a known theorem from automata theory relating the ..."
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Cited by 27 (2 self)
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We study the learnability of multiplicity automata in Angluin’s exact learning model, and we investigate its applications. Our starting point is a known theorem from automata theory relating the
Deterministic Automata on Unranked Trees
 In Proceedings of the 15th International Symposium on Fundamentals of Computation Theory (FCT), LNCS
, 2005
"... Abstract. We investigate bottomup and topdown deterministic automata on unranked trees. We show that for an appropriate denition of bottomup deterministic automata it is possible to minimize the number of states eciently and to obtain a unique canonical representative of the accepted tree langua ..."
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Cited by 26 (1 self)
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Abstract. We investigate bottomup and topdown deterministic automata on unranked trees. We show that for an appropriate denition of bottomup deterministic automata it is possible to minimize the number of states eciently and to obtain a unique canonical representative of the accepted tree language. For topdown deterministic automata it is well known that they are less expressive than the nondeterministic ones. By generalizing a corresponding proof from the theory of ranked tree automata we show that it is decidable whether a given regular language of unranked trees can be recognized by a topdown deterministic automaton. The standard deterministic topdown model is slightly weaker than the model we use, where at each node the automaton can scan the sequence of the labels of its successors before deciding its next move. 1