# Proceedings [1990] 31st Annual Symposium on Foundations of Computer Science

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Displaying Results 1 - 25 of 92
• ### No better ways to generate hard NP instances than picking uniformly at random

Publication Year: 1990, Page(s):812 - 821 vol.2
Cited by:  Papers (19)
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Distributed NP (DNP) problems are ones supplied with probability distributions of instances. It is shown that every DNP problem complete for P-time computable distributions is also complete for all distributions that can be sampled. This result makes the concept of average-case NP completeness robust and the question of the average-case complexity of complete DNP problems a natural alternative to ... View full abstract»

• ### Proceedings. 31st Annual Symposium on Foundations of Computer Science (Cat. No.90CH2925-6)

Publication Year: 1990
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• ### A characterization of #P by arithmetic straight line programs

Publication Year: 1990, Page(s):26 - 34 vol.1
Cited by:  Papers (2)
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#P functions are characterized by certain straight-line programs of multivariate polynomials. The power of this characterization is illustrated by a number of consequences. These include a somewhat simplified proof of S. Toda's (1989) theorem that PH⊆P#P, as well as an infinite class of potentially inequivalent checkable functions View full abstract»

• ### Nondeterministic exponential time has two-prover interactive protocols

Publication Year: 1990, Page(s):16 - 25 vol.1
Cited by:  Papers (18)
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The exact power of two-prover interactive proof systems (MIP) introduced by M. Ben-Or et al. (Proc. 20th Symp. on Theory of Computing, 1988, p.113-31) is determined. In this system, two all-powerful noncommunicating provers convince a randomizing polynomial-time verifier in polynomial time that the input x belongs to the language L. It was previously suspected (and proved in a re... View full abstract»

• ### The lattice reduction algorithm of Gauss: an average case analysis

Publication Year: 1990, Page(s):830 - 839 vol.2
Cited by:  Papers (1)
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The lattice reduction algorithm of Gauss is shown to have an average-case complexity that is asymptotic to a constant. The analysis makes use of elementary properties of continued fractions and of linear fractional transformations View full abstract»

• ### IP=PSPACE [interactive proof=polynomial space]

Publication Year: 1990, Page(s):11 - 15 vol.1
Cited by:  Papers (2)
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It is proved that, when both randomization and interaction are allowed, the proofs that can be verified in polynomial time are exactly those proofs that can be generated with polynomial space. The interactive proofs introduced use only public coins, are accepted with probability one when the prover is honest, require only logarithmic workspace when the verifier is given a two-way access to his or ... View full abstract»

• ### Approximation through multicommodity flow

Publication Year: 1990, Page(s):726 - 737 vol.2
Cited by:  Papers (15)
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The first approximate max-flow-min-cut theorem for general multicommodity flow is proved. It is used to obtain approximation algorithms for minimum deletion of clauses of a 2-CNF≡formula, via minimization problems, and other problems. Also presented are approximation algorithms for chordalization of a graph and for register sufficiency that are based on undirected and directed node separator... View full abstract»

• ### ON ACC and threshold circuits

Publication Year: 1990, Page(s):619 - 627 vol.2
Cited by:  Papers (43)
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It is proved that any language in ACC can be approximately computed by two-level circuits of size 2 raised to the (log n) k power, with a symmetric-function gate at the top and only AND gates on the first level. This implies that any language in ACC can be recognized by depth-3 threshold circuits of that size. This result gives the first nontrivial upper bound on the computing ... View full abstract»

• ### Sparse partitions

Publication Year: 1990, Page(s):503 - 513 vol.2
Cited by:  Papers (63)  |  Patents (3)
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A collection of clustering and decomposition techniques that make possible the construction of sparse and locality-preserving representations for arbitrary networks is presented. The representation method considered is based on breaking the network G(V,E) into connected regions, or clusters, thus obtaining a cover for the network, i.e. a collection of clusters that cover... View full abstract»

• ### Complexity of unification in free groups and free semi-groups

Publication Year: 1990, Page(s):824 - 829 vol.2
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It is proved that the exponent of periodicity of a minimal solution of a word equation is at most 22.54n, where n is the length of the equation. Since the best known lower bound is 20.31n, this upper bound is almost optimal and exponentially better than the original bound. Thus the result implies exponential improvement of known upper bounds on complexity of word-un... View full abstract»

• ### Algebraic methods for interactive proof systems

Publication Year: 1990, Page(s):2 - 10 vol.1
Cited by:  Papers (43)  |  Patents (1)
| | PDF (556 KB)

An algebraic technique for the construction of interactive proof systems is proposed. The technique is used to prove that every language in the polynomial-time hierarchy has an interactive proof system. For the proof, a method is developed for reducing the problem of verifying the value of a low-degree polynomial at two points to verifying the value at one new point. The results have implications ... View full abstract»

• ### Are wait-free algorithms fast?

Publication Year: 1990, Page(s):55 - 64 vol.1
Cited by:  Papers (2)
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The time complexity of wait-free algorithms in so-called 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 wait-free algorithm that achieves approximate agreement among n processes is proved. In contrast, there exists a non-wait-free algorithm that solves this prob... View full abstract»

• ### Interpolation of sparse rational functions without knowing bounds on exponents

Publication Year: 1990, Page(s):8409 - 8406 vol.2
Cited by:  Papers (4)
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The authors present the first algorithm for the (black box) interpolation of t-sparse, n-variate, rational functions without knowing bounds on exponents of their sparse representation, with the number of queries independent of exponents. In fact, the algorithm uses O(ntt) queries to the black box, and it can be implemented for a fixed t in a ... View full abstract»

• ### Trans-dichotomous algorithms for minimum spanning trees and shortest paths

Publication Year: 1990, Page(s):719 - 725 vol.2
Cited by:  Papers (19)
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The fusion tree method is extended to develop a linear-time algorithm for the minimum spanning tree problem and an O(m +n log n/log log n) implementation of Dijkstra's shortest-path algorithm for a graph with n vertices and m edges. The shortest-path algorithm surpasses information-theoretic limitations. The extension of the fusion tre... View full abstract»

• ### On the power of small-depth threshold circuits

Publication Year: 1990, Page(s):610 - 618 vol.2
Cited by:  Papers (9)
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The power of threshold circuits of small depth is investigated. In particular, functions that require exponential-size unweighted threshold circuits of depth 3 when the bottom fan-in is restricted are given. It is proved that there are monotone functions fk that can be computed on depth k and linear size AND, OR circuits but require exponential-size to be computed by a... View full abstract»

• ### Communication-optimal maintenance of replicated information

Publication Year: 1990, Page(s):492 - 502 vol.2
Cited by:  Papers (9)  |  Patents (2)
| | PDF (800 KB)

It is shown that keeping track of history allows significant improvements in the realistic model of communication complexity of dynamic network protocols. The communication complexity for solving an arbitrary graph problem is improved from Θ(E) to Θ( V), thus achieving the lower bound. Moreover, O(V) is also the amortized complexity of solving an arbitrary fu... View full abstract»

• ### Competitive k-server algorithms

Publication Year: 1990, Page(s):454 - 463 vol.2
Cited by:  Papers (7)
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Deterministic competitive k-server algorithms are given for all k and all metric spaces. This settles the k-server conjecture of M.S. Manasse et al. (1988) up to the competitive ratio. The best previous result for general metric spaces was a three-server randomized competitive algorithm and a nonconstructive proof that a deterministic three-server competitive algorithm e... View full abstract»

• ### Coin-flipping games immune against linear-sized coalitions

Publication Year: 1990, Page(s):46 - 54 vol.q
Cited by:  Papers (1)
| | PDF (488 KB)

It is proved that for every c<1 there are perfect-information coin-flipping and leader-election games on n players in which no coalition of cn players can influence the outcome with probability greater than some universal constant times c. It is shown that a random protocol of a certain length has this property, and an explicit construction is given as well View full abstract»

• ### On the diameter of finite groups

Publication Year: 1990, Page(s):857 - 865 vol.2
Cited by:  Papers (10)
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The diameter of a group G with respect to a set S of generators is the maximum over g∈G of the length of the shortest word in S∪S-1 representing g. This concept arises in the contexts of efficient communication networks and Rubik's-cube-type puzzles. Best' generators are pertinent to networks, whereas worst' and `average' ... View full abstract»

• ### General weak random sources

Publication Year: 1990, Page(s):534 - 543 vol.2
Cited by:  Papers (23)  |  Patents (2)
| | PDF (656 KB)

The following model for a weak random source is considered. The source is asked only once for R bits, and the source outputs an R-bit string such that no string has probability more than 2 -δR of being output. for some fixed δ>0. A pseudorandom generator that runs in time nO(log n) and simulates RP using as a seed a string from such a... View full abstract»

• ### Robust separations in inductive inference

Publication Year: 1990, Page(s):405 - 410 vol.1
Cited by:  Papers (6)
| | PDF (396 KB)

Results in recursion-theoretic inductive inference have been criticized as depending on unrealistic self-referential examples. J.M. Barzdin (1974) proposed a way of ruling out such examples and conjectured that one of the earliest results of inductive inference theory would fall if his method were used. The author refutes Barzdin's conjecture and proposes a new line of research examining robust se... View full abstract»

• ### A Markovian extension of Valiant's learning model

Publication Year: 1990, Page(s):392 - 396 vol.1
Cited by:  Papers (3)
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A model of learning that expands on the Valiant model is introduced. The point of departure from the Valiant model is that the learner is placed in a Markovian environment. The environment of the learner is a (exponentially large) graph, and the examples reside on the vertices of the graph, one example on each vertex. The learner obtains the examples while performing a random walk on the graph. At... View full abstract»

• ### Permuting

Publication Year: 1990, Page(s):372 - 379 vol.1
Cited by:  Patents (3)
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The fundamental problem of permuting the elements of an array according to some given permutation is addressed. The goal is to perform the permutation quickly using only a polylogarithmic number of bits of extra storage. The main result is an O(n log n)-time, O(log2n)-space worst case method. A simpler method is presented for the case in whic... View full abstract»

• ### Decision problems for propositional linear logic

Publication Year: 1990, Page(s):662 - 671 vol.2
Cited by:  Papers (14)  |  Patents (1)
| | PDF (712 KB)

It is shown that, unlike most other propositional (quantifier-free) logics, full propositional linear logic is undecidable. Further, it is provided that without the model storage operator, which indicates unboundedness of resources, the decision problem becomes PSPACE-complete. Also established are membership in NP for the multiplicative fragment, NP-completeness for the multiplicative fragment ex... View full abstract»

• ### Augmenting graphs to meet edge-connectivity requirements

Publication Year: 1990, Page(s):708 - 718 vol.2
Cited by:  Papers (19)  |  Patents (1)
| | PDF (716 KB)

The problem of determining the minimum number γ of edges to be added to a graph G so that in the resulting graph the edge-connectivity between every pair {u,v} of nodes is at least a prescribed value r(u,v) is treated. A min-max formula for γ is derived, and a polynomial-time algorithm for computing γ is described. The directe... View full abstract»