The 43rd Annual IEEE Symposium on Foundations of Computer Science, 2002. Proceedings.

19-19 Nov. 2002

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  • Proceedings 43rd Annual IEEE Symposium on Foundations of Computer Science

    Publication Year: 2002
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    Freely Available from IEEE
  • Zero-knowledge: abstract of a tutorial

    Publication Year: 2002
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (201 KB) | HTML iconHTML

    Zero-knowledge proofs are fascinating and extremely useful constructs. Their fascinating nature is due to their seemingly contradictory definition; zero-knowledge proofs are both convincing and yet yield nothing beyond the validity of the assertion being proven. Their applicability in the domain of cryptography is vast; they are typically used to force malicious parties to behave according to a pr... View full abstract»

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  • Randomness extractors and their many guises

    Publication Year: 2002
    Cited by:  Papers (7)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (217 KB) | HTML iconHTML

    Since its introduction by Nisan and Zuckerman at STOC '93 (1996) nearly a decade ago, the notion of a randomness extractor has proven to be a fundamental and powerful one. Extractors and their variants have found widespread application in a variety of areas, including pseudorandomness and derandomization, combinatorics, cryptography, data structures, and computational complexity. Equally striking ... View full abstract»

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  • Locally testable codes and PCPs of almost-linear length

    Publication Year: 2002, Page(s):13 - 22
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (420 KB) | HTML iconHTML

    Locally testable codes are error-correcting codes that admit very efficient codeword tests. Specifically, using a constant number of (random) queries, noncodewords are rejected with probability proportional to their distance from the code. Locally testable codes are believed to be the combinatorial core of PCPs. However, the relation is less immediate than commonly believed. Nevertheless, we show ... View full abstract»

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  • Hardness results for coloring 3-colorable 3-uniform hypergraphs

    Publication Year: 2002, Page(s):23 - 32
    Cited by:  Papers (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (379 KB) | HTML iconHTML

    We consider the problem of coloring a 3-colorable 3-uniform hypergraph. In the minimization version of this problem, given a 3-colorable 3-uniform hypergraph, one seeks an algorithm to color the hypergraph with as few colors as possible. We show that it is NP-hard to color a 3-colorable 3-uniform hypergraph with constantly many colors. In fact, we show a stronger result that it is NP-hard to disti... View full abstract»

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  • The hardness of 3-uniform hypergraph coloring

    Publication Year: 2002, Page(s):33 - 40
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (368 KB) | HTML iconHTML

    We prove that coloring a 3-uniform 2-colorable hypergraph with any constant number of colors is NP-hard. The best known algorithm (Krivelevich, Nathaniel, and Sudakov, 2001)colors such a graph using O(n/sup 1/5/) colors. Our result immediately implies that for any constants k > 2 and c/sub 2/ > c/sub 1/ > 1, coloring a k-uniform c/sub 1/-colorable hypergraph with c/sub 2/ colors is NP-har... View full abstract»

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  • Minimizing congestion in general networks

    Publication Year: 2002, Page(s):43 - 52
    Cited by:  Papers (47)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (390 KB) | HTML iconHTML

    A principle task in parallel and distributed systems is to reduce the communication load in the interconnection network, as this is usually the major bottleneck for the performance of distributed applications. We introduce a framework for solving online problems that aim to minimize the congestion (i.e. the maximum load of a network link) in general topology networks. We apply this framework to th... View full abstract»

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  • Small induced-universal graphs and compact implicit graph representations

    Publication Year: 2002, Page(s):53 - 62
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (392 KB) | HTML iconHTML

    We show that there exists a graph G with n /spl middot/ 2/sup O(log* n)/ nodes, where any forest with n nodes is a node-induced subgraph of G. Furthermore, the result implies the existence of a graph with n/sup k/2/sup O(log* n)/ nodes that contains all n-node graphs of fixed arboricity k as node-induced subgraphs. We provide a lower bound of /spl Omega/(n/sup k/) for the size of such a graph. The... View full abstract»

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  • Deterministic broadcasting time in radio networks of unknown topology

    Publication Year: 2002, Page(s):63 - 72
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (361 KB) | HTML iconHTML

    In a seminal paper, Bar-Yehuda et al. (1992) considered broadcasting in radio networks whose nodes know only their own label and labels of their neighbors. They claimed a linear lower bound on the time of deterministic broadcasting in such radio networks, by constructing a class of graphs of diameter 3, with the property that every broadcasting algorithm requires linear time on one of these graphs... View full abstract»

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  • Explicit unique-neighbor expanders

    Publication Year: 2002, Page(s):73 - 79
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (330 KB) | HTML iconHTML

    We present a simple, explicit construction of an infinite family F of bounded-degree 'unique-neighbor' expanders /spl Gamma/; i.e., there are strictly positive constants /spl alpha/ and /spl epsi/, such that all /spl Gamma/ = (X, E(/spl Gamma/)) /spl isin/ F satisfy the following property. For each subset S of X with no more than /spl alpha/|X| vertices, there are at least /spl epsi/|S| vertices i... View full abstract»

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  • Abstract combinatorial programs and efficient property testers

    Publication Year: 2002, Page(s):83 - 92
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (445 KB) | HTML iconHTML

    Property testing is a relaxation of classical decision problems which aims at distinguishing between functions having a predetermined property and functions being far from any function having the property. In this paper we present a novel framework for analyzing property testing algorithms with one-sided error. Our framework is based on a connection of property testing and a new class of problems ... View full abstract»

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  • A lower bound for testing 3-colorability in bounded-degree graphs

    Publication Year: 2002, Page(s):93 - 102
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (405 KB) | HTML iconHTML

    We consider the problem of testing 3-colorability in the bounded-degree model. We show that, for small enough /spl epsiv/, every tester for 3-colorability must have query complexity /spl Omega/(n). This is the first linear lower bound for testing a natural graph property in the bounded-degree model. An /spl Omega/(/spl radic/n) lower bound was previously known. For one-sided error testers, we also... View full abstract»

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  • Testing juntas [combinatorial property testing]

    Publication Year: 2002, Page(s):103 - 112
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (410 KB) | HTML iconHTML

    We show that a Boolean function over n Boolean variables can be tested for the property of depending on only k of them, using a number of queries that depends only on k and the approximation parameter /spl epsi/. We present two tests, both non-adaptive, that require a number of queries that is polynomial k and linear in /spl epsi//sup -1/. The first test is stronger in that it has a 1-sided error,... View full abstract»

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  • A spectral algorithm for learning mixtures of distributions

    Publication Year: 2002, Page(s):113 - 122
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (613 KB) | HTML iconHTML

    We show that a simple spectral algorithm for learning a mixture of k spherical Gaussians in /spl Ropf//sup n/ works remarkably well - it succeeds in identifying the Gaussians assuming essentially the minimum possible separation between their centers that keeps them unique. The sample complexity and running time are polynomial in both n and k. The algorithm also works for the more general problem o... View full abstract»

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  • Equivalence between priority queues and sorting

    Publication Year: 2002, Page(s):125 - 134
    Cited by:  Papers (6)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (365 KB) | HTML iconHTML

    We present a general deterministic linear space reduction from priority queues to sorting implying that if we can sort up to n keys in S(n) time per key, then there is a priority queue supporting delete and insert in S(n)+O(1) time and find-min in constant time. Conversely, a priority queue can trivially be used for sorting: first insert all keys to be sorted, then extract them in sorted order by ... View full abstract»

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  • Integer sorting in O(n/spl radic/(log log n)) expected time and linear space

    Publication Year: 2002, Page(s):135 - 144
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (372 KB) | HTML iconHTML

    We present a randomized algorithm sorting n integers in O(n/spl radic/(log log n)) expected time and linear space. This improves the previous O(n log log n) bound by Anderson et al. (1995). As an immediate consequence, if the integers are bounded by U, we can sort them in O(n/spl radic/(log log U)) expected time. This is the first improvement over the O (n log log U) bound obtained with van Emde B... View full abstract»

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  • Implicit B-trees: New results for the dictionary problem

    Publication Year: 2002, Page(s):145 - 154
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (379 KB) | HTML iconHTML

    We reopen the issue of finding an implicit data structure for the dictionary problem. In particular, we examine the problem of maintaining n data values in the first n locations of an array in such a way that we can efficiently perform the operations insert, delete and search. No information other than n and the data is to be retained; and the only operations which we may perform on the data value... View full abstract»

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  • An inverse-Ackermann style lower bound for the online minimum spanning tree verification problem

    Publication Year: 2002, Page(s):155 - 163
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (368 KB) | HTML iconHTML

    We consider the problem of preprocessing an edge-weighted tree T in order to quickly answer queries of the following type: does a given edge e belong in the minimum spanning tree of T /spl cup/ {e}? Whereas the offline minimum spanning tree verification problem admits a lovely linear time solution, we demonstrate an inherent inverse-Ackermann type tradeoff in the online MST verification problem. I... View full abstract»

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  • PAC=PAExact and other equivalent models in learning

    Publication Year: 2002, Page(s):167 - 176
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1900 KB) | HTML iconHTML

    The probably almost exact model (PAExact) can be viewed as the exact model relaxed so that: 1. The counterexamples to equivalence queries are distributionally drawn rather than adversarially chosen. 2. The output hypothesis is equal to the target with negligible error (1//spl omega/(poly) for any poly). This model allows studying (almost) exact learnability of infinite classes and is in some sense... View full abstract»

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  • Learning intersections and thresholds of halfspaces

    Publication Year: 2002, Page(s):177 - 186
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (389 KB) | HTML iconHTML

    We give the first polynomial time algorithm to learn any function of a constant number of halfspaces under the uniform distribution to within any constant error parameter. We also give the first quasipolynomial time algorithm for learning any function of a polylog number of polynomial-weight halfspaces under any distribution. As special cases of these results we obtain algorithms for learning inte... View full abstract»

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  • On-line confidence machines are well-calibrated

    Publication Year: 2002, Page(s):187 - 196
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (411 KB) | HTML iconHTML

    Transductive Confidence Machine (TCM) and its computationally efficient modification, inductive confidence machine (ICM), are ways of complementing machine-learning algorithms with practically useful measures of confidence. We show that when TCM and ICM are used in the on-line mode, their confidence measures are well-calibrated, in the sense that predictive regions at confidence level 1-/spl delta... View full abstract»

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  • Learning a hidden matching

    Publication Year: 2002, Page(s):197 - 206
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (373 KB) | HTML iconHTML

    We consider the problem of learning a matching (i.e., a graph in which all vertices have degree 0 or 1) in a model where the only allowed operation is to query whether a set of vertices induces an edge. This is motivated by a problem that arises in molecular biology. In the deterministic nonadaptive setting, we prove a ( 1/2 +o(1))(n/2) upper bound and a nearly matching 0.32(n/2) lower bound for t... View full abstract»

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  • An information statistics approach to data stream and communication complexity

    Publication Year: 2002, Page(s):209 - 218
    Cited by:  Papers (27)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (427 KB) | HTML iconHTML

    We present a new method for proving strong lower bounds in communication complexity. This method is based on the notion of the conditional information complexity of a function which is the minimum amount of information about the inputs that has to be revealed by a communication protocol for the function. While conditional information complexity is a lower bound on the communication complexity, we ... View full abstract»

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  • Static optimality theorem for external memory string access

    Publication Year: 2002, Page(s):219 - 227
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (378 KB) | HTML iconHTML

    Data warehouses are increasingly storing and managing large scale string data, and dealing with large volume of transactions that update and search string data. Motivated by this context, we initiate the study of self-adjusting data structures for string dictionary operations, that is, data structures that are designed to be efficient on an entire sequence rather than individual string operations.... View full abstract»

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  • A simple algorithmic characterization of uniform solvability

    Publication Year: 2002, Page(s):228 - 237
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (361 KB) | HTML iconHTML

    The Herlihy-Shavit (HS) conditions characterizing the solvability of asynchronous tasks over n processors have been a milestone in the development of the theory of distributed computing. Yet, they were of no help when researcher sought algorithms that do not depend on n. To help in this pursuit we investigate the uniform solvability of an infinite uniform sequence of tasks T/sub 0/, T/sub 1/, T/su... View full abstract»

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