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44th Annual IEEE Symposium on Foundations of Computer Science, 2003. Proceedings.

11-14 Oct. 2003

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Displaying Results 1 - 25 of 66
  • Separating the power of monotone span programs over different fields

    Publication Year: 2003, Page(s):428 - 501
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (605 KB) | HTML iconHTML

    Monotone span programs are a linear-algebraic model of computation. They are equivalent to linear secret sharing schemes and have various applications in cryptography and complexity. A fundamental question is how the choice of the field in which the algebraic operations are performed effects the power of the span program. In this paper we prove that the power of monotone span programs over finite ... View full abstract»

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  • Stability and efficiency of a random local load balancing protocol

    Publication Year: 2003, Page(s):472 - 481
    Cited by:  Papers (2)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (518 KB) | HTML iconHTML

    We study the long term (steady state) performance of a simple, randomized, local load balancing technique. We assume a system of n processors connected by an arbitrary network topology. Jobs are placed in the processors by a deterministic or randomized adversary. The adversary knows the current and past load distribution in the network and can use this information to place the new tasks in the pro... View full abstract»

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  • Average case and smoothed competitive analysis of the multi-level feedback algorithm

    Publication Year: 2003, Page(s):462 - 471
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (531 KB) | HTML iconHTML

    In this paper, we introduce the notion of smoothed competitive analysis of online algorithms. Smoothed analysis has been proposed by Spielman and Teng (2001) to explain the behavior of algorithms that work well in practice while performing very poorly from a worst case analysis point of view. We apply this notion to analyze the Multi-Level Feedback (MLF) algorithm to minimize the total flow time o... View full abstract»

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  • Locally testable cyclic codes

    Publication Year: 2003, Page(s):116 - 125
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (842 KB) | HTML iconHTML

    Cyclic linear codes of block length n over a finite field Fq are the linear subspaces of Fqn that are invariant under a cyclic shift of their coordinates. A family of codes is good if all the codes in the family have constant rate and constant normalized distance (distance divided by block length). It is a long-standing open problem whether there exists a good fami... View full abstract»

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  • Group strategy proof mechanisms via primal-dual algorithms

    Publication Year: 2003, Page(s):584 - 593
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (397 KB) | HTML iconHTML

    We develop a general method for turning a primal-dual algorithm into a group strategy proof cost-sharing mechanism. We use our method to design approximately budget balanced cost sharing mechanisms for two NP-complete problems: metric facility location, and single source rent-or-buy network design. Both mechanisms are competitive, group strategyproof and recover a constant fraction of the cost. Fo... View full abstract»

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  • Bounded geometries, fractals, and low-distortion embeddings

    Publication Year: 2003, Page(s):534 - 543
    Cited by:  Papers (50)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (386 KB) | HTML iconHTML

    The doubling constant of a metric space (X, d) is the smallest value λ such that every ball in X can be covered by λ balls of half the radius. The doubling dimension of X is then defined as dim (X) = log2λ. A metric (or sequence of metrics) is called doubling precisely when its doubling dimension is bounded. This is a robust class of metric spaces which contains man... View full abstract»

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  • Symmetric polynomials over Zm and simultaneous communication protocols

    Publication Year: 2003, Page(s):450 - 459
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (560 KB) | HTML iconHTML

    We study the problem of representing symmetric Boolean functions as symmetric polynomials over Zm. We show an equivalence between such representations and simultaneous communication protocols. Computing a function f on 0 - 1 inputs with a polynomial of degree d modulo pq is equivalent to a two player simultaneous protocol for computing f where one player is given the first [logp View full abstract»

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  • On the (In)security of the Fiat-Shamir paradigm

    Publication Year: 2003, Page(s):102 - 113
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (508 KB) | HTML iconHTML

    In 1986, Fiat and Shamir proposed a general method for transforming secure 3-round public-coin identification schemes into digital signature schemes. The idea of the transformation was to replace the random message of the verifier in the identification scheme, with the value of some deterministic hash function evaluated on various quantities in the protocol and on the message to be signed. The Fia... View full abstract»

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  • Instability of FIFO at arbitrarily low rates in the adversarial queuing model

    Publication Year: 2003, Page(s):160 - 167
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB) | HTML iconHTML

    We study the stability of the commonly used packet forwarding protocol, FIFO (First In First Out), in the adversarial queuing model. We prove that FIFO can become unstable, i.e., lead to unbounded buffer-occupancies and queuing delays, at arbitrarily low injection rates. In order to demonstrate instability at rate r, we use a network of size polynomial in 1/r. View full abstract»

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  • Towards a characterization of truthful combinatorial auctions

    Publication Year: 2003, Page(s):574 - 583
    Cited by:  Papers (24)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (419 KB) | HTML iconHTML

    This paper analyzes incentive compatible (truthful) mechanisms over restricted domains of preferences, the leading example being combinatorial auctions. Our work generalizes the characterization of Roberts (1979) who showed that truthful mechanisms over unrestricted domains with at least 3 possible outcomes must be "affine maximizers". We show that truthful mechanisms for combinatorial auctions (a... View full abstract»

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  • Clustering with qualitative information

    Publication Year: 2003, Page(s):524 - 533
    Cited by:  Papers (26)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (342 KB) | HTML iconHTML

    We consider the problem of clustering a collection of elements based on pairwise judgments of similarity and dissimilarity. N. Bansal et al. (2002) cast the problem thus: given a graph G whose edges are labeled "+" (similar) or "-" (dissimilar), partition the vertices into clusters so that the number of pairs correctly (resp. incorrectly) classified with respect to the input labeling is maximized ... View full abstract»

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  • A group-theoretic approach to fast matrix multiplication

    Publication Year: 2003, Page(s):438 - 449
    Cited by:  Papers (16)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (675 KB) | HTML iconHTML

    We develop a new, group-theoretic approach to bounding the exponent of matrix multiplication. There are two components to this approach: (1) identifying groups G that admit a certain type of embedding of matrix multiplication into the group algebra C[G], and (2) controlling the dimensions of the irreducible representations of such groups. We present machinery and examples to support (1), including... View full abstract»

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  • Breaking a time-and-space barrier in constructing full-text indices

    Publication Year: 2003, Page(s):251 - 260
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (501 KB) | HTML iconHTML

    Suffix trees and suffix arrays are the most prominent full-text indices, and their construction algorithms are well studied. It has been open for a long time whether these indices can be constructed in both O(n log n) time and O(n log n)-bit working space, where n denotes the length of the text. In the literature, the fastest algorithm runs in O(n) time, while it requires O(n log n)-bit working sp... View full abstract»

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  • Deterministic extractors for bit-fixing sources and exposure-resilient cryptography

    Publication Year: 2003, Page(s):92 - 101
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (376 KB) | HTML iconHTML

    We give an efficient deterministic algorithm which extracts Ω(n2γ) almost-random bits from sources where n12 + γ/ of the n bits are uniformly random and the rest are fixed in advance. This improves on previous constructions which required that at least n/2 of the bits be random. Our construction also gives explicit adaptive exposure-resilient functions and i... View full abstract»

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  • Proving hard-core predicates using list decoding

    Publication Year: 2003, Page(s):146 - 157
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1117 KB) | HTML iconHTML

    We introduce a unifying framework for proving that predicate P is hard-core for a one-way function f, and apply it to a broad family of functions and predicates, reproving old results in an entirely different way as well as showing new hard-core predicates for well known one-way function candidates. Our framework extends the list-coding method of Goldreich and Levin for showing hard-core predicate... View full abstract»

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  • Towards a dichotomy theorem for the counting constraint satisfaction problem

    Publication Year: 2003, Page(s):562 - 571
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (478 KB) | HTML iconHTML

    The Counting Constraint Satisfaction Problem (#CSP) over a finite domain can be expressed as follows: given a first-order formula consisting of a conjunction of predicates, determine the number of satisfying assignments to the formula. #CSP can be parametrized by the set of allowed constraint predicates. In this paper we start a systematic study of subclasses of #CSP restricted in this way. The ul... View full abstract»

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  • Algorithms and complexity results for #SAT and Bayesian inference

    Publication Year: 2003, Page(s):340 - 351
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (403 KB) | HTML iconHTML

    Bayesian inference is an important problem with numerous applications in probabilistic reasoning. Counting satisfying assignments is a closely related problem of fundamental theoretical importance. In this paper, we show that plain old DPLL equipped with memorization (an algorithm we call #DPLLCache) can solve both of these problems with time complexity that is at least as good as state-of-the-art... View full abstract»

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  • On the impossibility of dimension reduction in ℓ1

    Publication Year: 2003, Page(s):514 - 523
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (329 KB) | HTML iconHTML

    The Johnson-Lindenstrauss Lemma shows that any n points in Euclidean space (with distances measured by the ℓ2 norm) may be mapped down to O((log n)/ε2) dimensions such that no pairwise distance is distorted by more than a (1+ ε) factor. Determining whether such dimension reduction is possible in ℓ1 has been an intriguing open question. We show... View full abstract»

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  • Solving sparse, symmetric, diagonally-dominant linear systems in time O(m1.31

    Publication Year: 2003, Page(s):416 - 427
    Cited by:  Papers (6)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (687 KB) | HTML iconHTML

    We present a linear-system solver that, given an n-by-n symmetric positive semi-definite, diagonally dominant matrix A with m non-zero entries and an n-vector b, produces a vector x˜ within relative distance ε of the solution to Ax = b in time O(m1.31log(n/ε)bO(1)), where b is the log of the ratio of the largest to smallest non-zero entry of A. If the graph of... View full abstract»

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  • An in-place sorting with O(n log n) comparisons and O(n) moves

    Publication Year: 2003, Page(s):242 - 250
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (329 KB) | HTML iconHTML

    We present the first in-place algorithm for sorting an array of size n that performs, in the worst case, at most O(n log n) element comparisons and O(n) element transports. This solves a long-standing open problem, stated explicitly, e.g., in J.I. Munro and V. Raman (1992), of whether there exists a sorting algorithm that matches the asymptotic lower bounds on all computational resources simultane... View full abstract»

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  • Zero-knowledge sets

    Publication Year: 2003, Page(s):80 - 91
    Cited by:  Papers (30)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (611 KB) | HTML iconHTML

    We show how a polynomial-time prover can commit to an arbitrary finite set S of strings so that, later on, he can, for any string x, reveal with a proof whether x ∈ S or x ∉ S, without revealing any knowledge beyond the verity of these membership assertions. Our method is non interactive. Given a public random string, the prover commits to a set by simply posting a short and easily comp... View full abstract»

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  • On ϵ-biased generators in NC0

    Publication Year: 2003, Page(s):136 - 145
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (354 KB) | HTML iconHTML

    M. Cryan and P.B. Miltersen (2001) recently considered the question of whether there can be a pseudorandom generator in NC0, that is, a pseudorandom generator that maps n bits strings to m bits strings and such that every bit of the output depends on a constant number k of bits of the seed. They show that for k = 3, if m ≥ 4n + 1, there is a distinguisher; in fact, they show that in ... View full abstract»

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  • The complexity of homomorphism and constraint satisfaction problems seen from the other side

    Publication Year: 2003, Page(s):552 - 561
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (448 KB) | HTML iconHTML

    We give a complexity theoretic classification of homomorphism problems for graphs and, more generally, relational structures obtained by restricting the left hand side structure in a homomorphism. For every class C of structures, let HOM(C, _) be the problem of deciding whether a given structure A ∈ C has a homomorphism to a given (arbitrary) structure B. We prove that, under some comple... View full abstract»

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  • Always Good Turing: asymptotically optimal probability estimation

    Publication Year: 2003, Page(s):179 - 188
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (814 KB) | HTML iconHTML

    While deciphering the German Enigma code during World War II, I.J. Good and A.M. Turing considered the problem of estimating a probability distribution from a sample of data. They derived a surprising and unintuitive formula that has since been used in a variety of applications and studied by a number of researchers. Borrowing an information-theoretic and machine-learning framework, we define the ... View full abstract»

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  • On the maximum satisfiability of random formulas

    Publication Year: 2003, Page(s):362 - 370
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (329 KB) | HTML iconHTML

    Maximum satisfiability is a canonical NP-complete problem that appears empirically hard for random instances. At the same time, it is rapidly becoming a canonical problem for statistical physics. In both of these realms, evaluating new ideas relies crucially on knowing the maximum number of clauses one can typically satisfy in a random k-CNF formula. In this paper we give asymptotically tight esti... View full abstract»

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