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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
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    Freely Available from IEEE
  • Efficient tree pattern matching

    Publication Year: 1989, Page(s):178 - 183
    Cited by:  Papers (16)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB)

    A classic open problem on tree pattern matching is whether the naive O(mn)-step algorithm for finding all the occurrences of a pattern tree of size m in a text tree of size n can be improved. An O(nM0.75 polylog(m))-step algorithm for this tree pattern matching problem is designed. The problems of linear string matching with... 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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  • 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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  • The 0-1 law fails for the class of existential second order Godel sentences with equality

    Publication Year: 1989, Page(s):160 - 163
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (212 KB)

    P. Kolaitis and M. Vardi (see Proc. 19th ACM Symp. on Theory of Computing, p.425-35 (1987), and Proc. 3rd Ann. Symp. on Logic in Computer Science, p.2-11 (1988)) proved that the 0-1 law holds for the second-order existential sentences whose first-order parts are formulas of Bernays-Schonfinkel or Ackermann prefix classes. They also provided several examples of second-order formulas for which the 0... View full abstract»

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  • Efficient NC algorithms for set cover with applications to learning and geometry

    Publication Year: 1989, Page(s):54 - 59
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (596 KB)

    NC approximation algorithms are given for the unweighted and weighted set cover problems. The algorithms use a linear number of processors and give a cover that has at most log n times the optimal size/weight, thus matching the performance of the best sequential algorithms. The set cover algorithm is applied to learning theory, providing an NC algorithm for learning the concept class obta... View full abstract»

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  • A note on the power of threshold circuits

    Publication Year: 1989, Page(s):580 - 584
    Cited by:  Papers (37)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (292 KB)

    The author presents a very simple proof of the fact that any language accepted by polynomial-size depth-k unbounded-fan-in circuits of AND and OR gates is accepted by depth-three threshold circuits of size n raised to the power O(logk n). The proof uses much of the intuition of S. Toda's result that the polynomial hierarchy is contained in P#P View full abstract»

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  • Characterizations of the basic feasible functionals of finite type

    Publication Year: 1989, Page(s):154 - 159
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (444 KB)

    The authors define a simple typed while-programming language that generalizes the sort of simple language used in computability texts to define the familiar numerical computable functions and corresponds roughly to the μ-recursion of R.O. Gandy (1967). This language does not fully capture the notion of higher type computability. The authors define run times for their programs and prove that the... View full abstract»

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  • Learning binary relations and total orders

    Publication Year: 1989, Page(s):46 - 51
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (556 KB)

    The problem of designing polynomial prediction algorithms for learning binary relations is studied for an online model in which the instances are drawn by the learner, by a helpful teacher, by an adversary, or according to a probability distribution on the instance space. The relation is represented as an n×m binary matrix, and results are presented when the matrix is restr... 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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  • Constant depth circuits, Fourier transform, and learnability

    Publication Year: 1989, Page(s):574 - 579
    Cited by:  Papers (23)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (456 KB)

    Boolean functions in ACO are studied using the harmonic analysis of the cube. The main result is that an ACO Boolean function has almost all of its power spectrum on the low-order coefficients. This result implies the following properties of functions in ACO: functions in ACO have low average sensitivity; they can be approximated well be a real polynomia... 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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  • 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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  • 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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  • 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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  • Subquadratic simulations of circuits by branching programs

    Publication Year: 1989, Page(s):568 - 573
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (332 KB)

    Boolean circuits and their simulations by bounded-width branching programs are considered. It is shown that every NC1 circuit of size s can be simulated by a constant-width branching program of length s1.811. . .. Some related group-theoretic results are presented View full abstract»

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  • Datalog vs. first-order logic

    Publication Year: 1989, Page(s):142 - 147
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (388 KB)

    The relation between the expressive power of datalog and that of first-order languages, is clarified. It is then proved that every first-order expressible datalog query is bounded. A form of compactness theorem for finite structure implied by this result is examined, and counterexamples to natural generalizations of the above result are given 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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  • Computational complexity of roots of real functions

    Publication Year: 1989, Page(s):204 - 209
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (476 KB)

    An attempt is made to give a more accurate classification of the computational complexity of roots of real functions. Attention is focused on the simplest types of functions, namely, one-to-one and k -to-one functions, and the complexity of their roots is characterized in terms of relations between discrete complexity classes, such as LOGSPACE, P, UP, and NP View full abstract»

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  • On the computational power of PP and ⊕P

    Publication Year: 1989, Page(s):514 - 519
    Cited by:  Papers (48)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    Two complexity classes, PP and ⊕P, are compared with PH (the polynomial-time hierarchy). The main results are as follows: (1) every set in PH is reducible in a certain sense to a set in PP, an (2) every set in PH is reducible to a set in ⊕P under randomized polynomial-time reducibility with two-sided bounded error probability. It follows from these results that neither PP nor ⊕P ... View full abstract»

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  • Dynamically computing the maxima of decomposable functions, with applications

    Publication Year: 1989, Page(s):488 - 493
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (496 KB)

    The authors present a general technique for updating the maximum (minimum) value of a decomposable function as elements are inserted into and deleted from the set S. Applications of this technique include efficient algorithms for dynamically computing the diameter or closest pair of a set of points, minimum separation among a set of rectangles, smallest distance between a set of points an... View full abstract»

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  • Probabilistic communication complexity of Boolean relations

    Publication Year: 1989, Page(s):562 - 567
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (352 KB)

    The authors demonstrate an exponential gap between deterministic and probabilistic complexity and between the probabilistic complexity of monotonic and nonmonotonic relations. They then prove, as their main result, an Ω((log n)2) bound on the probabilistic communication complexity of monotonic st-connectivity. From this they deduce that every nonmonotonic NC... View full abstract»

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  • Approximation schemes for constrained scheduling problems

    Publication Year: 1989, Page(s):134 - 139
    Cited by:  Papers (21)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (556 KB)

    Several constrained scheduling problems are considered. The first polynomial approximation schemes for the problem of minimizing maximum completion time in a two-machine flow shop with release dates and for the problem of minimizing maximum lateness for the single and parallel-machine problem with release dates are described. All of these algorithms are based upon the notion of an outline, a set o... View full abstract»

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  • An efficient parallel algorithm for the minimal elimination ordering (MEO) of an arbitrary graph

    Publication Year: 1989, Page(s):454 - 459
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (384 KB)

    The first efficient parallel algorithm for computing minimal elimination ordering (MEO) of an arbitrary graph is designed. The algorithm works in O(log3n) parallel time and O(nm) processors on a concurrent-read-concurrent-write parallel random-access machine (CRCW PRAM) for an n-vertex, m-edge graph and is optimal up to polylogarithm... View full abstract»

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  • The strength of weak learnability

    Publication Year: 1989, Page(s):28 - 33
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (520 KB)

    The problem of improving the accuracy of a hypothesis output by a learning algorithm in the distribution-free learning model is considered. A concept class is learnable (or strongly learnable) if, given access to a source of examples from the unknown concept, the learner with high probability is able to output a hypothesis that is correct on all but an arbitrarily small fraction of the instances. ... View full abstract»

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