Lynch, Nancy A. (Nancy Ann) 1948
Overview
Works:  134 works in 383 publications in 1 language and 2,555 library holdings 

Genres:  Conference papers and proceedings 
Roles:  Author, Editor, Creator 
Publication Timeline
.
Most widely held works about
Nancy A Lynch
Most widely held works by
Nancy A Lynch
Distributed algorithms by
Nancy A Lynch(
Book
)
31 editions published between 1996 and 2010 in English and Undetermined and held by 560 WorldCat member libraries worldwide
The presentation is completely rigorous, yet is intuitive enough for immediate comprehension. This book familiarizes readers with important problems, algorithms, and impossibility results in the area: readers can then recognize the problems when they arise in practice, apply the algorithms to solve them, and use the impossibility results to determine whether problems are unsolvable
31 editions published between 1996 and 2010 in English and Undetermined and held by 560 WorldCat member libraries worldwide
The presentation is completely rigorous, yet is intuitive enough for immediate comprehension. This book familiarizes readers with important problems, algorithms, and impossibility results in the area: readers can then recognize the problems when they arise in practice, apply the algorithms to solve them, and use the impossibility results to determine whether problems are unsolvable
Hybrid systems : computation and control : Third International Workshop, HSCC 2000, Pittsburgh, PA, USA, March 2325, 2000
: proceedings by
Nancy Lynch(
Book
)
19 editions published between 2000 and 2002 in English and held by 255 WorldCat member libraries worldwide
This book constitutes the refereed proceedings of the Third International Workshop on Hybrid Systems: Computation and Control, HSCC 2000, held in Pittsburgh, PA, USA in March 2000. The 32 revised full papers presented together with abstracts of four invited talks were carefully reviewed and selected from a total of 71 papers submitted. The focus of the works presented is on modeling, control, synthesis, design and verification of hybrid systems. Among the application areas covered are control of electromechanical systems, air traffic control, control of automated freeways, and chemical process control
19 editions published between 2000 and 2002 in English and held by 255 WorldCat member libraries worldwide
This book constitutes the refereed proceedings of the Third International Workshop on Hybrid Systems: Computation and Control, HSCC 2000, held in Pittsburgh, PA, USA in March 2000. The 32 revised full papers presented together with abstracts of four invited talks were carefully reviewed and selected from a total of 71 papers submitted. The focus of the works presented is on modeling, control, synthesis, design and verification of hybrid systems. Among the application areas covered are control of electromechanical systems, air traffic control, control of automated freeways, and chemical process control
Atomic transactions by
Nancy A Lynch(
Book
)
7 editions published in 1994 in English and held by 193 WorldCat member libraries worldwide
7 editions published in 1994 in English and held by 193 WorldCat member libraries worldwide
Distributed computing : 24th international symposium, DISC 2010, Cambridge, MA, USA, September 1315, 2010 ; proceedings by
Nancy A Lynch(
)
14 editions published in 2010 in English and held by 42 WorldCat member libraries worldwide
This book constitutes the refereed proceedings of the 24th International Symposium on Distributed Computing, DISC 2010, held in Cambridge, CT, USA, in September 2010. The 32 revised full papers, selected from 135 submissions, are presented together with 14 brief announcements of ongoing works; all of them were carefully reviewed and selected for inclusion in the book. The papers address all aspects of distributed computing, and were organized in topical sections on, transactions, shared memory services and concurrency, wireless networks, best student paper, consensus and leader election, mobile agents, computing in wireless and mobile networks, modeling issues and adversity, and selfstabilizing and graph algorithms
14 editions published in 2010 in English and held by 42 WorldCat member libraries worldwide
This book constitutes the refereed proceedings of the 24th International Symposium on Distributed Computing, DISC 2010, held in Cambridge, CT, USA, in September 2010. The 32 revised full papers, selected from 135 submissions, are presented together with 14 brief announcements of ongoing works; all of them were carefully reviewed and selected for inclusion in the book. The papers address all aspects of distributed computing, and were organized in topical sections on, transactions, shared memory services and concurrency, wireless networks, best student paper, consensus and leader election, mobile agents, computing in wireless and mobile networks, modeling issues and adversity, and selfstabilizing and graph algorithms
The theory of timed I/O automata by
Dilsun K Kaynar(
Book
)
3 editions published in 2006 in English and held by 33 WorldCat member libraries worldwide
This monograph presents the timed input/output automaton (TIOA) modeling framework, a basic mathematical framework to support description and analysis of timed (computing) systems. Timed systems are systems in which desirable correctness or performance properties of the system depend on the timing of events, not just on the order of their occurrence. Timed systems are employed in a wide range of domains including communications, embedded systems, realtime operating systems, and automated control. Many applications involving timed systems have strong safety, reliability, and predictability requirements, which makes it important to have methods for systematic design of systems and rigorous analysis of timingdependent behavior
3 editions published in 2006 in English and held by 33 WorldCat member libraries worldwide
This monograph presents the timed input/output automaton (TIOA) modeling framework, a basic mathematical framework to support description and analysis of timed (computing) systems. Timed systems are systems in which desirable correctness or performance properties of the system depend on the timing of events, not just on the order of their occurrence. Timed systems are employed in a wide range of domains including communications, embedded systems, realtime operating systems, and automated control. Many applications involving timed systems have strong safety, reliability, and predictability requirements, which makes it important to have methods for systematic design of systems and rigorous analysis of timingdependent behavior
Using mappings to prove timing properties by
Nancy A Lynch(
Book
)
16 editions published between 1989 and 1992 in English and held by 27 WorldCat member libraries worldwide
A new technique for proving timing properties for timing based algorithms is described; it is an extension of the mapping techniques previously used in proofs of safety properties for asynchronous concurrent systems. The key to the method is a way of representing a system with timing constraints as an automaton whose state includes predictive timing information. Timing assumptions and timing requirements for the system are both represented in this way. A multivalued mapping from the assumptions automaton to the requirements automaton is then used to show that the given system satisfies the requirements. One type of mapping is based on a collection of variant functions providing measures of progress toward timing goals. The technique is illustrated with two examples, a simple resource manager and a twoprocess race system
16 editions published between 1989 and 1992 in English and held by 27 WorldCat member libraries worldwide
A new technique for proving timing properties for timing based algorithms is described; it is an extension of the mapping techniques previously used in proofs of safety properties for asynchronous concurrent systems. The key to the method is a way of representing a system with timing constraints as an automaton whose state includes predictive timing information. Timing assumptions and timing requirements for the system are both represented in this way. A multivalued mapping from the assumptions automaton to the requirements automaton is then used to show that the given system satisfies the requirements. One type of mapping is based on a collection of variant functions providing measures of progress toward timing goals. The technique is illustrated with two examples, a simple resource manager and a twoprocess race system
Relativization of the theory of computational complexity by
Nancy A Lynch(
Book
)
10 editions published in 1972 in English and held by 17 WorldCat member libraries worldwide
Blum's machineindependent treatment of the complexity of partial recursive functions is extended to relative algorithms (as represented by Turing machines with oracles). The author proves relativeizations of several results of Blum complexity theory. A recursive relatedness theorem is proved, showing that any two relative complexity measures are related by a fixed recursive function. This theorem allows one to obtain proofs of results for all measures from proofs for a particular measure. The author studies complexitydetermined reducibilities, the parallel notion to complexity classes for the relativized case. Truthtable and primitive recursive reducibilities are reducibilities of this type. The concept of a set helping the computation of a function is formalized. Basic properties of the helping relation are proved, including nontransitivity and bounds on the amount of help certain sets can provide. (Author)
10 editions published in 1972 in English and held by 17 WorldCat member libraries worldwide
Blum's machineindependent treatment of the complexity of partial recursive functions is extended to relative algorithms (as represented by Turing machines with oracles). The author proves relativeizations of several results of Blum complexity theory. A recursive relatedness theorem is proved, showing that any two relative complexity measures are related by a fixed recursive function. This theorem allows one to obtain proofs of results for all measures from proofs for a particular measure. The author studies complexitydetermined reducibilities, the parallel notion to complexity classes for the relativized case. Truthtable and primitive recursive reducibilities are reducibilities of this type. The concept of a set helping the computation of a function is formalized. Basic properties of the helping relation are proved, including nontransitivity and bounds on the amount of help certain sets can provide. (Author)
Time bounds for realtime process control in the presence of timing uncertainty by
Hagit Attiya(
Book
)
7 editions published between 1989 and 1991 in English and held by 14 WorldCat member libraries worldwide
Abstract: "A timingbased variant of the mutual exclusion problem is considered. In this variant, only an upperbound, m, on the time it takes to release the resource is known, and no explicit signal is sent when the resource is released; furthermore, the only mechanism to measure real time is an inaccurate clock, whose tick intervals take time between two constants, c₁ [<or =] c₂. When control is centralized it is proved that [formula] is an exact bound on the worst case response time for any such algorithm, where n is the number of contenders for the resource and l is an upper bound on process step time. On the other hand, when control is distributed among processes connected via communication lines with an upper bound, d, for message delivery time, it is proved that [formula] is an upper bound. A new technique involving shifting and shrinking executions is combined with a careful analysis of the best allocation policy to prove a corresponding lower bound of [formula]. These combinatorial results shed some light on modeling and verification issues related to realtime systems."
7 editions published between 1989 and 1991 in English and held by 14 WorldCat member libraries worldwide
Abstract: "A timingbased variant of the mutual exclusion problem is considered. In this variant, only an upperbound, m, on the time it takes to release the resource is known, and no explicit signal is sent when the resource is released; furthermore, the only mechanism to measure real time is an inaccurate clock, whose tick intervals take time between two constants, c₁ [<or =] c₂. When control is centralized it is proved that [formula] is an exact bound on the worst case response time for any such algorithm, where n is the number of contenders for the resource and l is an upper bound on process step time. On the other hand, when control is distributed among processes connected via communication lines with an upper bound, d, for message delivery time, it is proved that [formula] is an upper bound. A new technique involving shifting and shrinking executions is combined with a careful analysis of the best allocation policy to prove a corresponding lower bound of [formula]. These combinatorial results shed some light on modeling and verification issues related to realtime systems."
Hybrid I/O automata by
Nancy A Lynch(
Book
)
8 editions published between 1995 and 2002 in English and Undetermined and held by 14 WorldCat member libraries worldwide
Abstract: "We propose a new hybrid I/O automaton model that is capable of describing both continuous and dicrete behavior. The model, which extends the timed I/O automaton model of [12, 7] and the phase transition system models of [15, 2], allows communication among components using both shared variables and shared actions. The main contributions of this paper are: (1) the definition of hybrid I/O automata and of an implementation relation based on hybrid traces, (2) the definition of a simulation between hybrid I/O automata and a proof that existence of a simulation implies the implementation relation, (3) a definition of composition of hybrid I/O automata and a proof that it respects the implementation relation, and (4) a definition of receptiveness for hybrid I/O automata and a proof that, assuming certain compatibility conditions, receptiveness is preserved by composition."
8 editions published between 1995 and 2002 in English and Undetermined and held by 14 WorldCat member libraries worldwide
Abstract: "We propose a new hybrid I/O automaton model that is capable of describing both continuous and dicrete behavior. The model, which extends the timed I/O automaton model of [12, 7] and the phase transition system models of [15, 2], allows communication among components using both shared variables and shared actions. The main contributions of this paper are: (1) the definition of hybrid I/O automata and of an implementation relation based on hybrid traces, (2) the definition of a simulation between hybrid I/O automata and a proof that existence of a simulation implies the implementation relation, (3) a definition of composition of hybrid I/O automata and a proof that it respects the implementation relation, and (4) a definition of receptiveness for hybrid I/O automata and a proof that, assuming certain compatibility conditions, receptiveness is preserved by composition."
Forward and backward simulations by
Nancy A Lynch(
Book
)
12 editions published between 1993 and 1994 in English and held by 12 WorldCat member libraries worldwide
12 editions published between 1993 and 1994 in English and held by 12 WorldCat member libraries worldwide
Action transducers and timed automata by
Nancy A Lynch(
Book
)
7 editions published between 1992 and 1994 in English and held by 11 WorldCat member libraries worldwide
Abstract: "The timed automaton model of [29,30] is a general model for timingbased systems. A notion of timed action transducer is here defined as an automatatheoretic way of representing operations on timed automata. It is shown that two timed trace inclusion relations are substitutive with respect to operations that can be described by timed action transducers. Examples are given of operations that can be described in this way, and a preliminary proposal is given for an appropriate language of operators for describing timingbased systems."
7 editions published between 1992 and 1994 in English and held by 11 WorldCat member libraries worldwide
Abstract: "The timed automaton model of [29,30] is a general model for timingbased systems. A notion of timed action transducer is here defined as an automatatheoretic way of representing operations on timed automata. It is shown that two timed trace inclusion relations are substitutive with respect to operations that can be described by timed action transducers. Examples are given of operations that can be described in this way, and a preliminary proposal is given for an appropriate language of operators for describing timingbased systems."
Impossibility of distributed consensus with one faulty process by
Michael J Fischer(
Book
)
5 editions published in 1982 in English and held by 10 WorldCat member libraries worldwide
The consensus problem involves an asynchronous system of processes, some of which may be unreliable. The problem is for the reliable processes to agree on a binary value. We show that every protocol for this problem has the possibility of nontermination, even with only one faulty process. By way of contrast, solutions are known for the synchronous case, the Byzantine Generals problem. (Author)
5 editions published in 1982 in English and held by 10 WorldCat member libraries worldwide
The consensus problem involves an asynchronous system of processes, some of which may be unreliable. The problem is for the reliable processes to agree on a binary value. We show that every protocol for this problem has the possibility of nontermination, even with only one faulty process. By way of contrast, solutions are known for the synchronous case, the Byzantine Generals problem. (Author)
Concurrency control for resilient nested transactions by
Nancy A Lynch(
Book
)
5 editions published between 1983 and 1986 in English and held by 10 WorldCat member libraries worldwide
A formal framework is developed for providing correctness of algorithms which implement nested transactions. In particular, a simple action tree data structure is defined, which describes the ancestor relationships among executing transactions and also describes the views which different transactions have of the data. A generalization of serializability to the domain of nested transactions with failures is defined. A characterization is given for this generalization of serializability, in terms of absence of cycles in an appropriate dependency relation on transactions. A slightly simplified version of Moss' locking algorithm is presented in detail, and a careful correctness proof is given. The style of correctness proof appears to be quite interesting in its own right. The description of the algorithm, from its initial specification to its detailed implementation, is presented as a series of eventstate algebra levels, each of which simulates the previous one in a straightforward way. (Author)
5 editions published between 1983 and 1986 in English and held by 10 WorldCat member libraries worldwide
A formal framework is developed for providing correctness of algorithms which implement nested transactions. In particular, a simple action tree data structure is defined, which describes the ancestor relationships among executing transactions and also describes the views which different transactions have of the data. A generalization of serializability to the domain of nested transactions with failures is defined. A characterization is given for this generalization of serializability, in terms of absence of cycles in an appropriate dependency relation on transactions. A slightly simplified version of Moss' locking algorithm is presented in detail, and a careful correctness proof is given. The style of correctness proof appears to be quite interesting in its own right. The description of the algorithm, from its initial specification to its detailed implementation, is presented as a series of eventstate algebra levels, each of which simulates the previous one in a straightforward way. (Author)
Hierarchical correctness proofs for distributed algorithms by M. R Tuttle(
Book
)
4 editions published in 1987 in English and held by 10 WorldCat member libraries worldwide
This thesis introduces a new model for distributed computation in asynchronous networks, the inputoutput automaton. This simple, powerful model captures in a novel way the gametheoretical interaction between a system and its environment, and allows fundamental properties of distributed computation such as fair computation to be naturally expressed. Furthermore, this model can be used to construct modular, hierarchical correctness proofs of distributed algorithms. This thesis defines the inputoutput automaton model, and presents an interesting example of how this model can be used to construct such proofs
4 editions published in 1987 in English and held by 10 WorldCat member libraries worldwide
This thesis introduces a new model for distributed computation in asynchronous networks, the inputoutput automaton. This simple, powerful model captures in a novel way the gametheoretical interaction between a system and its environment, and allows fundamental properties of distributed computation such as fair computation to be naturally expressed. Furthermore, this model can be used to construct modular, hierarchical correctness proofs of distributed algorithms. This thesis defines the inputoutput automaton model, and presents an interesting example of how this model can be used to construct such proofs
Multilevel atomicity : a new correctness criterion for database concurrency control by
Nancy A Lynch(
Book
)
5 editions published in 1982 in English and held by 10 WorldCat member libraries worldwide
Multilevel atomicity, a new correctness criteria for database concurrency control, is defined. It weakens the usual notion of serializability by permitting controlled interleaving among transactions. It appears to be especially suitable for applications in which the set of transactions has a natural hierarchical structure based on the hierarchical structure of an organization. A characterization for multilevel atomicity, in terms of absence of cycles in a dependency relation among transaction steps, is given. Some remarks are made concerning implementation. (Author)
5 editions published in 1982 in English and held by 10 WorldCat member libraries worldwide
Multilevel atomicity, a new correctness criteria for database concurrency control, is defined. It weakens the usual notion of serializability by permitting controlled interleaving among transactions. It appears to be especially suitable for applications in which the set of transactions has a natural hierarchical structure based on the hierarchical structure of an organization. A characterization for multilevel atomicity, in terms of absence of cycles in a dependency relation among transaction steps, is given. Some remarks are made concerning implementation. (Author)
The Byzantine firing squad problem by
J. E Burns(
Book
)
3 editions published in 1985 in English and held by 9 WorldCat member libraries worldwide
A new problem, the Byzantine Firing Squad problem, is defined and solved in two versions, Permissive and Strict. Both problems provide for synchronization of initially unsynchronized processors in a synchronous network, in the absence of a common clock and in the presence of a limited number of faulty processors. Solution are given which take the same number of rounds as Byzantine Agreement but might transmit r times as many bits, where r is the number of rounds used. Additional solutions are provided which use at most one (Permissive) or two (Strict) additional rounds and send at most n sub 2 bits plus four times the number of bits sent by a chosen Byzantine Agreement algorithm. Additional keywords: Computer communications. (Author)
3 editions published in 1985 in English and held by 9 WorldCat member libraries worldwide
A new problem, the Byzantine Firing Squad problem, is defined and solved in two versions, Permissive and Strict. Both problems provide for synchronization of initially unsynchronized processors in a synchronous network, in the absence of a common clock and in the presence of a limited number of faulty processors. Solution are given which take the same number of rounds as Byzantine Agreement but might transmit r times as many bits, where r is the number of rounds used. Additional solutions are provided which use at most one (Permissive) or two (Strict) additional rounds and send at most n sub 2 bits plus four times the number of bits sent by a chosen Byzantine Agreement algorithm. Additional keywords: Computer communications. (Author)
Correctness conditions for highly available replicated databases by
Nancy A Lynch(
Book
)
3 editions published in 1986 in English and held by 9 WorldCat member libraries worldwide
Correctness conditions are given which describe some of the properties exhibited by highly available distributed database systems such as the SHARD (System for Highly Available Replicated Data) system currently being developed at Computer Corporation of America. This system allows a database application to continue operation in the face of communication failures, including network partitions. A penalty is paid for this extra availability: the usual correctness conditions, serializability of transactions and preservation of integrity constraints, are not guaranteed. However, it is still possible to make interesting claims about the behavior of the system. The kinds of claims which can be proved include bounds on the costs of violation of integrity constraints, and fairness guarantees. In contrast to serializability's allornothing character, this work has a continuous flavor: small changes in available information lead to small perturbations in correctness conditions. This work is novel, because there has been very little previous success in stating interesting properties which are guaranteed by nonserializable systems. (Author)
3 editions published in 1986 in English and held by 9 WorldCat member libraries worldwide
Correctness conditions are given which describe some of the properties exhibited by highly available distributed database systems such as the SHARD (System for Highly Available Replicated Data) system currently being developed at Computer Corporation of America. This system allows a database application to continue operation in the face of communication failures, including network partitions. A penalty is paid for this extra availability: the usual correctness conditions, serializability of transactions and preservation of integrity constraints, are not guaranteed. However, it is still possible to make interesting claims about the behavior of the system. The kinds of claims which can be proved include bounds on the costs of violation of integrity constraints, and fairness guarantees. In contrast to serializability's allornothing character, this work has a continuous flavor: small changes in available information lead to small perturbations in correctness conditions. This work is novel, because there has been very little previous success in stating interesting properties which are guaranteed by nonserializable systems. (Author)
Probabilistic analysis of a network resource allocation algorithm by
Nancy A Lynch(
Book
)
7 editions published between 1983 and 1985 in English and held by 9 WorldCat member libraries worldwide
A distributed algorithm is presented, for allocating a large number of identical resources (such as airline tickets) to requests which can arrive anywhere in a distributed network. Resources, once allocated, are never returned. The algorithm searches sequentially, exhausting certain neighborhoods of the request origin before proceeding to search at greater distances. Choice of search direction is made nondeterministically. Analysis of expected response time is simplified by assuming that the search direction is chosen probabilistically, that messages require constant time, that the network is a tree with all leaves at the same distance from the root, and that requests and resources occur only at leaves. It is shown that the response time is approximated by the number of messages of one that are sent during the execution of the algorithm, and that this number of message is a nondecreasing function of the interarrival time for requests. Therefore, the worst case occurs when requests come in so far apart that they are processed sequentially. The expected time for the sequential case of the algorithm is analyzed by standard techniques. This time is shown to be bounded by a constant, independent of the size of the network. It follows that the expected response time for the algorithm is bounded in the same way. (Author)
7 editions published between 1983 and 1985 in English and held by 9 WorldCat member libraries worldwide
A distributed algorithm is presented, for allocating a large number of identical resources (such as airline tickets) to requests which can arrive anywhere in a distributed network. Resources, once allocated, are never returned. The algorithm searches sequentially, exhausting certain neighborhoods of the request origin before proceeding to search at greater distances. Choice of search direction is made nondeterministically. Analysis of expected response time is simplified by assuming that the search direction is chosen probabilistically, that messages require constant time, that the network is a tree with all leaves at the same distance from the root, and that requests and resources occur only at leaves. It is shown that the response time is approximated by the number of messages of one that are sent during the execution of the algorithm, and that this number of message is a nondecreasing function of the interarrival time for requests. Therefore, the worst case occurs when requests come in so far apart that they are processed sequentially. The expected time for the sequential case of the algorithm is analyzed by standard techniques. This time is shown to be bounded by a constant, independent of the size of the network. It follows that the expected response time for the algorithm is bounded in the same way. (Author)
Multivalued possibilities mappings by
Nancy A Lynch(
Book
)
5 editions published in 1990 in English and held by 9 WorldCat member libraries worldwide
Abstraction mappings are one of the major tools used to construct correctness proofs for concurrent algorithms. Several examples are given of situations in which it is useful to allow the abstraction mappings to be multivalued. The examples involve algorithm optimization, algorithm distribution, and proofs of time bounds. Abstraction mappings are one of the major tools that the author and colleagues use to construct correctness proofs for concurrent (including distributed) algorithms. In this paper, she tries to make one major point about such mappings: that it is useful to allow them to be multivalued. That is, often when one maps a lowlevel algorithm L to a high level algorithm H, one would like to allow several states of H to correspond to a single state of L.I believe that any useful framework for describing abstraction mappings should include the ability to describe multivalued mappings
5 editions published in 1990 in English and held by 9 WorldCat member libraries worldwide
Abstraction mappings are one of the major tools used to construct correctness proofs for concurrent algorithms. Several examples are given of situations in which it is useful to allow the abstraction mappings to be multivalued. The examples involve algorithm optimization, algorithm distribution, and proofs of time bounds. Abstraction mappings are one of the major tools that the author and colleagues use to construct correctness proofs for concurrent (including distributed) algorithms. In this paper, she tries to make one major point about such mappings: that it is useful to allow them to be multivalued. That is, often when one maps a lowlevel algorithm L to a high level algorithm H, one would like to allow several states of H to correspond to a single state of L.I believe that any useful framework for describing abstraction mappings should include the ability to describe multivalued mappings
Are waitfree algorithms fast? by
H Attiya(
Book
)
4 editions published in 1991 in English and held by 8 WorldCat member libraries worldwide
The time complexity of waitfree algorithms in normal executions, where no failures occur and processes operate at approximately the same speed, is considered. A lower bound of log n on the time complexity of any waitfree algorithm that achieves approximate agreement among n processes is proved. In contrast, there exists a nonwaitfree algorithm that solves this problem in constant time. This implies an omega (log n) time separation between the waitfree and nonwaitfree computation models. On the positive side, we present an O(log n) time waitfree approximate agreement algorithm; the complexity of this algorithm is within a small constant of the lower bound
4 editions published in 1991 in English and held by 8 WorldCat member libraries worldwide
The time complexity of waitfree algorithms in normal executions, where no failures occur and processes operate at approximately the same speed, is considered. A lower bound of log n on the time complexity of any waitfree algorithm that achieves approximate agreement among n processes is proved. In contrast, there exists a nonwaitfree algorithm that solves this problem in constant time. This implies an omega (log n) time separation between the waitfree and nonwaitfree computation models. On the positive side, we present an O(log n) time waitfree approximate agreement algorithm; the complexity of this algorithm is within a small constant of the lower bound
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Abstraction Algorithms Artificial intelligence Carson, W. H Computational complexity Computer algorithms Computer inputoutput equipment Computer networks Computers, Special purpose Computer science Computer simulation Computer software Database management Digital control systems Distributed databases Electronic data processingDistributed processing Electronic data processingDistributed processingMathematical models Electronic data processingDistributed processingReliability Engineering Faulttolerant computing Garbage collection (Computer science) Hybrid computers Interior architecture Logic design Machine theory Mappings (Mathematics) Miller, G. P Miller, J. L Network analysis (Planning) Physics Probabilities Proof theoryData processing Railroad stations Realtime control Realtime data processing Reasoning Recursive functions Software engineering South CarolinaColumbia Southern Railway (U.S.) Structural control (Engineering) Temporal automata Transaction systems (Computer systems) Trees (Graph theory) Turing machines
Alternative Names
Lynch, N. 1948
Lynch, N. A. 1948
Lynch, Nancy.
Lynch, Nancy 1948
Lynch, Nancy A.
Lynch, Nancy Ann 1948
Nancy Lynch Amerikaans informatica
Nancy Lynch amerikansk informatikar
Nancy Lynch amerikansk informatiker
Nancy Lynch chercheuse américaine
Nancy Lynch científica y profesora estadounidense
Nancy Lynch informatica statunitense
Nancy Lynch USamerikanische Informatikerin
Nancy Lynchová
Ненсі Лінч
Нэнси Линч американский учёный
نانسی لینچ دانشمند علوم کامپیوتر آمریکایی
ナンシー・リンチ
南希·林奇
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