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30th Annual Symposium on Foundations of Computer Science

Oct. 30 1989-Nov. 1 1989

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  • 30th Annual Symposium on Foundations of Computer Science (Cat. No.89CH2808-4)

    Publication Year: 1989
    Request permission for commercial reuse | PDF file iconPDF (78 KB)
    Freely Available from IEEE
  • Testing permutation polynomials

    Publication Year: 1989, Page(s):88 - 92
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (316 KB)

    The simple test for determining whether an arbitrary polynomial is a permutation polynomial, by producing its list of values, is considered, and it is found that off-the-shelf techniques from computer algebra improve the running time slightly, without requiring any new insights into the problem. A probabilistic variant of the Hermite test that reduces its running time is given. A criterion for per... View full abstract»

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  • The inverse of an automorphism in polynomial time

    Publication Year: 1989, Page(s):82 - 87
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB)

    The first known polynomial-time algorithm for computing the inverse of a K-algebra automorphism is presented. The algorithm works over a commutative ring K and is based on a polynomial decomposition algorithm. A polynomial-time algorithm for computing the left composition factor of a multivariate decomposition is also presented. Two related open problems are stated View full abstract»

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  • Generalizing the PAC model: sample size bounds from metric dimension-based uniform convergence results

    Publication Year: 1989, Page(s):40 - 45
    Cited by:  Papers (19)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (528 KB)

    The probably approximately correct (PAC) model of learning from examples is generalized. The problem of learning functions from a set X into a set Y is considered, assuming only that the examples are generated by independent draws according to an unknown probability measure on X×Y. The learner's goal is to find a function in a given hypothesis space of fun... View full abstract»

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  • Structure in locally optimal solutions

    Publication Year: 1989, Page(s):216 - 221
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (432 KB)

    A class of local search problems, PLS (polynomial-time local search), as defined by D.S. Johnson et al. (see J. Comput. Syst. Sci., vol.37, no.1, p.79-100 (1988)) is considered. PLS captures much of the structure of NP problems at the level of their feasible solutions and neighborhoods. It is first shown that CNF (conjunctive normal form) satisfiability is PLS-complete, even with simultaneously bo... View full abstract»

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  • Full abstraction for nondeterministic dataflow networks

    Publication Year: 1989, Page(s):170 - 175
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (484 KB)

    The problem of finding fully abstract semantic models for nondeterministic dataflow networks is discussed. The author presents a result indicating that there exist nondeterministic networks using only bounded choice for which the input-output relation is not compositional. It is shown that the trace semantics is fully abstract for all nondeterministic as well as deterministic networks View full abstract»

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  • Conductance and convergence of Markov chains-a combinatorial treatment of expanders

    Publication Year: 1989, Page(s):526 - 531
    Cited by:  Papers (23)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (400 KB)

    A direct combinatorial argument is given to bound the convergence rate of Markov chains in terms of their conductance (these are statements of the nature `random walks on expanders converge fast'). In addition to showing that the linear algebra in previous arguments for such results on time-reversible Markov chains was unnecessary, the direct analysis applies to general irreversible Markov chains View full abstract»

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  • A randomized maximum-flow algorithm

    Publication Year: 1989, Page(s):118 - 123
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (488 KB)

    The authors present a randomized maximum-flow algorithm, called the PLED (prudent linking excess diminishing) algorithm, whose expected running time is O(nm+n2(log n )3); this is O(nm) for all except relatively sparse networks. The algorithm is always correct, and in the worst case, which occurs with negligible probability... View full abstract»

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  • An upper bound on the number of planar k-sets

    Publication Year: 1989, Page(s):72 - 79
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    Given a set S of n points, a subset X of size k is called a k-set if there is a hyperplane II that separates X from Xc. It is proved that O(nk/log*k) is an upper bound for the number of k-sets in the plane, thus improving the previous bound of P. Erdos et al. (A ... View full abstract»

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  • A theory of learning simple concepts under simple distributions and average case complexity for the universal distribution

    Publication Year: 1989, Page(s):34 - 39
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (624 KB)

    It is pointed out that in L.G. Valiant's learning model (Commun. ACM, vol.27, p.1134-42, 1984) many concepts turn out to be too hard to learn, whereas in practice, almost nothing we care to learn appears to be not learnable. To model the intuitive notion of learning more closely, it is assumed that learning happens under an arbitrary distribution, rather than under an arbitrary simple distribution... View full abstract»

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  • On the power of 2-way probabilistic finite state automata

    Publication Year: 1989, Page(s):480 - 485
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (436 KB)

    The recognition power of two-way probabilistic finite-state automata (2PFAs) is studied. It is shown that any 2PFA recognizing a nonregular language must use exponential expected time infinitely often. The power of interactive proof systems (IPSs) where the verifier is a 2PFA is also investigated. It is shown that (1) IPSs in which the verifier uses private randomization are strictly more powerful... View full abstract»

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  • Efficient cryptographic schemes provably as secure as subset sum

    Publication Year: 1989, Page(s):236 - 241
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (448 KB)

    Very efficient constructions, based on the intractability of the subset sum problem for certain dimensions, are shown for a pseudorandom generator and for a universal one-way hash function. (Pseudorandom generators can be used for private key encryption, and universal one-way hash functions for signature schemes). The increase in efficiency in the construction is due to the fact that many bits can... View full abstract»

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  • Sorting on a parallel pointer machine with applications to set expression evaluation

    Publication Year: 1989, Page(s):190 - 195
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (564 KB)

    Optimal algorithms for sorting on parallel CREW (concurrent read, exclusive write) and EREW (exclusive read, exclusive write) versions of the pointer machine model are presented. Intuitively, these methods can be viewed as being based on the use of linked lists rather than arrays (the usual parallel data structure). It is shown how to exploit the `locality' of the approach to solve a problem with ... View full abstract»

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  • On the complexity of fixed parameter problems

    Publication Year: 1989, Page(s):210 - 215
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (384 KB)

    The authors address the question of why some fixed-parameter problem families solvable in polynomial time seem to be harder than others with respect to fixed-parameter tractability: whether there is a constant α such that all problems in the family are solvable in time O(nα). The question is modeled by considering a class of polynomially indexed relations. ... View full abstract»

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  • A really temporal logic

    Publication Year: 1989, Page(s):164 - 169
    Cited by:  Papers (48)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (484 KB)

    A real-time temporal logic for the specification of reactive systems is introduced. The novel feature of the logic, TPTL, is the adoption of temporal operators as quantifiers over time variables; every modality binds a variable to the time(s) it refers to. TPTL is demonstrated to be both a natural specification language and a suitable formalism for verification and synthesis. A tableau-based decis... View full abstract»

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  • Decidability and expressiveness for first-order logics of probability

    Publication Year: 1989, Page(s):148 - 153
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (500 KB)

    Decidability and expressiveness issues for two first-order logics of probability are considered. In one the probability is on possible worlds, whereas in the other it is on the domain. It turns out that in both cases it takes very little to make reasoning about probability highly undecidable. It is shown that, when the probability is on the domain, if the language contains only unary predicates, t... View full abstract»

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  • Every polynomial-time 1-degree collapses iff P=PSPACE

    Publication Year: 1989, Page(s):624 - 629
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB)

    A set A is m-reducible (or Karp-reducible) to B if and only if there is a polynomial-time computable function f such that for all x, xA if and only if f(x)∈B. Two sets are 1-equivalent if each is m-reducible to the other by one-one reductions; p-invertible equivalent iff each is ... View full abstract»

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  • On obstructions in relation to a fixed viewpoint

    Publication Year: 1989, Page(s):592 - 597
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (616 KB)

    108 Efficient, randomized algorithms are given for the following problems: (1) construction of levels of order 1 to k in an arrangement of hyperplanes in any dimension; (2) construction of higher order Voronoi diagrams of order 1 to k in any dimension; (3) hidden surface removal for completely general scenes (intersecting and curved faces are allowed). A combinatorial tool in the... View full abstract»

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  • An analogue of the Myhill-Nerode theorem and its use in computing finite-basis characterizations

    Publication Year: 1989, Page(s):520 - 525
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (448 KB)

    A theorem that is a graph-theoretic analog of the Myhill-Nerode characterization of regular languages is proved. The theorem is used to establish that for many applications obstruction sets are computable by known algorithms. The focus is exclusively on what is computable (by a known algorithm) in principle, as opposed to what is computable in practice View full abstract»

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  • Simplification of nested radicals

    Publication Year: 1989, Page(s):314 - 319
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (428 KB)

    Radical simplification is a fundamental mathematical question, as well as an important part of symbolic computation systems. The general denesting problem had not been known to be decidable. Necessary and sufficient conditions for a radical α over a field k to be denested, as well as the first algorithm to decide whether the expression can be denested, are given. The algorithm compu... View full abstract»

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  • Incremental planarity testing

    Publication Year: 1989, Page(s):436 - 441
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (436 KB)

    The incremental planarity testing problem consists of performing the following operations on a planar graph G with n vertices: (1) testing whether a new edge can be added to G so that the resulting graph is itself planar; (2) adding vertices and edges such that planarity is preserved. An efficient technique for incremental planarity testing that uses O(... View full abstract»

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  • Flow in planar graphs with multiple sources and sinks

    Publication Year: 1989, Page(s):112 - 117
    Cited by:  Papers (5)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (504 KB)

    Given a planar network with many sources and sinks, the problem of computing the maximum flow from the sources to the sinks is investigated. An algorithm that runs in O(log2n ) time using O(n1.5) processors on an exclusive-read-exclusive-write parallel random-access machine (EREW PRAM) is obtained, when the amount of flow (demand) at each s... View full abstract»

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  • Ensemble motion planning in trees

    Publication Year: 1989, Page(s):66 - 71
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (472 KB)

    The problem of transporting a set of objects between the vertices of a tree by a unit capacity vehicle that travels along the edges of the tree is considered. For the case in which any object can be dropped at intermediate vertices along its route and picked up later, the authors present algorithms for finding a minimum cost transportation that run in O(k+qn) time and in... View full abstract»

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  • Space-efficient static trees and graphs

    Publication Year: 1989, Page(s):549 - 554
    Cited by:  Papers (102)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (380 KB)

    Data structures that represent static unlabeled trees and planar graphs are developed. The structures are more space efficient than conventional pointer-based representations, but (to within a constant factor) they are just as time efficient for traversal operations. For trees, the data structures described are asymptotically optimal: there is no other structure that encodes n-node trees ... View full abstract»

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  • On the complexity of learning from counterexamples

    Publication Year: 1989, Page(s):262 - 267
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (472 KB)

    The complexity of learning concepts belonging to various concrete concept classes C⊆2X over a finite domain X is analyzed in terms of the number of counterexamples that are needed in the worst case. It turns out that for many interesting concept classes there exist exponential differences between the number of counterexamples that are required by a `naive' learni... View full abstract»

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