By Topic

Proceedings 38th Annual Symposium on Foundations of Computer Science

20-22 Oct. 1997

Filter Results

Displaying Results 1 - 25 of 65
  • Proceedings 38th Annual Symposium on Foundations of Computer Science

    Publication Year: 1997
    Request permission for commercial reuse | PDF file iconPDF (277 KB)
    Freely Available from IEEE
  • Author index

    Publication Year: 1997, Page(s):605 - 606
    Request permission for commercial reuse | PDF file iconPDF (94 KB)
    Freely Available from IEEE
  • Improved approximations for edge-disjoint paths, unsplittable flow, and related routing problems

    Publication Year: 1997, Page(s):416 - 425
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (872 KB)

    We present improved approximation algorithms for a family of problems involving edge-disjoint paths and unsplittable flow, and for some related routing problems. The central theme of all our algorithms is the underlying multi-commodity flow relaxation View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A 7/8-approximation algorithm for MAX 3SAT?

    Publication Year: 1997, Page(s):406 - 415
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (884 KB)

    We describe a randomized approximation algorithm which takes an instance of MAX 3SAT as input. If the instance-a collection of clauses each of length at most three-is satisfiable, then the expected weight of the assignment found is at least 7/8 of optimal. We provide strong evidence (but not a proof) that the algorithm performs equally well on arbitrary MAX 3SAT instances. Our algorithm uses semid... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A random sampling based algorithm for learning the intersection of half-spaces

    Publication Year: 1997, Page(s):508 - 513
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (564 KB)

    We present an algorithm for learning the intersection of half spaces in n dimensions. Over nearly uniform distributions, it runs in polynomial time for up to O(logn/loglogn) half spaces or, more generally for any number of half spaces whose normal vectors lie in an O(log n/log log n) dimensional subspace. Over less restricted “non-concentrated” distributions it runs in polynomial time ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A concrete security treatment of symmetric encryption

    Publication Year: 1997, Page(s):394 - 403
    Cited by:  Papers (118)  |  Patents (18)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (952 KB)

    We study notions and schemes for symmetric (ie. private key) encryption in a concrete security framework. We give four different notions of security against chosen plaintext attack and analyze the concrete complexity of reductions among them, providing both upper and lower bounds, and obtaining tight relations. In this way we classify notions (even though polynomially reducible to each other) as s... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hamiltonian cycles in solid grid graphs

    Publication Year: 1997, Page(s):496 - 505
    Cited by:  Papers (7)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (824 KB)

    A grid graph is a finite node induced subgraph of the infinite two dimensional integer grid. A solid grid graph is a grid graph without holes. For general grid graphs, the Hamiltonian cycle problem is known to be NP complete. We give a polynomial time algorithm for the Hamiltonian cycle problem in solid grid graphs, resolving a longstanding open question posed by A. Itai et al. (1982). In fact, ou... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Randomized and deterministic algorithms for the dimension of algebraic varieties

    Publication Year: 1997, Page(s):36 - 45
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (848 KB)

    We prove old and new results on the complexity of computing the dimension of algebraic varieties. In particular, we show that this problem is NP-complete in the Blum-Shub-Smale model of computation over C, that it admits a sO(1)DO(n) deterministic algorithm, and that for systems with integer coefficients it is in the Arthur-Merlin class under the Generalized Riemann Hypothesi... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Contention resolution with guaranteed constant expected delay

    Publication Year: 1997, Page(s):213 - 222
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (880 KB)

    We study contention resolution in multiple-access channels such as the Ethernet. Under a stochastic model of continuous packet generation from a set of n processors, we construct a protocol which guarantees constant expected delay for generation rates up to a fixed constant λ0<1. Previous protocols which are stable for constant arrival rates do not guarantee constant expected ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimal-resilience proactive public-key cryptosystems

    Publication Year: 1997, Page(s):384 - 393
    Cited by:  Papers (38)  |  Patents (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1004 KB)

    We introduce new efficient techniques for sharing cryptographic functions in a distributed dynamic fashion. These techniques dynamically and securely transform a distributed function (or secret sharing) representation between t-out-of-l (polynomial sharing) and t-out-of-t (additive sharing). We call the techniques poly-to-sum and sum-to-poly, respectively. Employing these techniques, we solve a nu... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Edge-connectivity augmentation preserving simplicity

    Publication Year: 1997, Page(s):486 - 495
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (856 KB)

    Given a simple graph G=(V, E), the goal is to find a smallest set F of new edges such that G=(V, E∪F) is κ edge connected and simple. Very recently this problem was shown to be NP hard by T. Jordan (1997). We prove that if OPTPκ is high enough-depending on κ only-then OPTSκ=OPTPκ holds, where OPT View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The computational complexity of knot and link problems

    Publication Year: 1997, Page(s):172 - 181
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (912 KB)

    We consider the problem of deciding whether a polygonal knot in 3-dimensional Euclidean space is unknotted (that is, whether it is capable of being continuously deformed without self-intersection so that it lies in a plane). We show that this problem, UNKNOTTING PROBLEM, is in NP. We also consider the problem, SPLITTING PROBLEM, of determining whether two or more such polygons can be split (that i... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Lower bounds for the signature size of incremental schemes

    Publication Year: 1997, Page(s):438 - 447
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (924 KB)

    We show lower bounds for the signature size of incremental schemes which are secure against substitution attacks and support single block replacement. We prove that for documents of n blocks such schemes produce signatures of Ω(n1(2+c)/) bits for any constant c>0. For schemes accessing only a single block resp. A constant number of blocks for each replacement this bound can be ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Nearly tight bounds on the learnability of evolution

    Publication Year: 1997, Page(s):524 - 533
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (952 KB)

    Evolution is often modeled as a stochastic process which modifies DNA. One of the most popular and successful such processes are the Cavender-Farris (CF) trees, which are represented as edge weighted trees. The Phylogeny Construction Problem is that of, given κ samples drawn from a CF tree, output a CF tree which is close to the original. Each CF tree naturally defines a random variable, and... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Separation of the monotone NC hierarchy

    Publication Year: 1997, Page(s):234 - 243
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (864 KB)

    We prove tight lower bounds, of up to nε, for the monotone depth of functions in monotone-P. As a result we achieve the separation of the following classes. 1. Monotone-NC≠monotone-P. 2. ∀i⩾1, monotone-NCi≠monotone-NCi+1. 3. More generally: For any integer function D(n), up to nε (for some ε>0), we give an explicit exa... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • No feasible interpolation for TC0-Frege proofs

    Publication Year: 1997, Page(s):254 - 263
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (752 KB)

    The interpolation method has been one of the main tools for proving lower bounds for propositional proof systems. Loosely speaking, if one can prove that a particular proof system has the feasible interpolation property, then a generic reduction can (usually) be applied to prove lower bounds for the proof system, sometimes assuming a (usually modest) complexity-theoretic assumption. In this paper,... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Flows in undirected unit capacity networks

    Publication Year: 1997, Page(s):32 - 34
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (252 KB)

    We describe an O(min(m, n3/2)m1/2)-time algorithm for finding maximum flows in undirected networks with unit capacities and no parallel edges. This improves upon the previous bound of Karzanov and Even and Tarjan when m=ω(n3/2), and upon a randomized bound of Karger when υ=Ω(n7/4/m 1/2) View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Succinct representation of balanced parentheses, static trees and planar graphs

    Publication Year: 1997, Page(s):118 - 126
    Cited by:  Papers (13)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (868 KB)

    We consider the implementation of abstract data types for the static objects: binary tree, rooted ordered tree and balanced parenthesis expression. Our representations use an amount of space within a lower order term of the information theoretic minimum and support, in constant time, a richer set of navigational operations than has previously been considered in similar work. In the case of binary ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Minimizing flow time nonclairvoyantly

    Publication Year: 1997, Page(s):345 - 352
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (604 KB)

    We consider the problem of scheduling a collection of dynamically arriving jobs with unknown execution times so as to minimize the average response/flow time. This is the classic CPU scheduling problem faced by time sharing operating systems. In the standard 3-field scheduling notation this is the nonclairvoyant version of 1|pmtn, rj|ΣFj. Its easy to see that every algo... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Undirected single source shortest paths in linear time

    Publication Year: 1997, Page(s):12 - 21
    Cited by:  Papers (8)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (900 KB)

    The single source shortest paths problem (SSSP) is one of the classic problems in algorithmic graph theory: given a weighted graph G with a source vertex s, find the shortest path from s to all other vertices in the graph. Since 1959 all theoretical developments in SSSP have been based on Dijkstra's algorithm, visiting the vertices in order of increasing distance from s. Thus, any implementation o... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Alternating-time temporal logic

    Publication Year: 1997, Page(s):100 - 109
    Cited by:  Papers (55)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (984 KB)

    Temporal logic comes in two varieties: linear-time temporal logic assumes implicit universal quantification over all paths that are generated by system moves; branching-time temporal logic allows explicit existential and universal quantification over all paths. We introduce a third, more general variety of temporal logic: alternating-time temporal logic offers selective quantification over those p... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Truly online paging with locality of reference

    Publication Year: 1997, Page(s):326 - 335
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (824 KB)

    The access graph model for paging, defined by (Borodin et al., 1991) and studied in (Irani et al., 1992) has a number of troubling aspects. The access graph has to be known in advance to the paging algorithm and the memory required to represent the access graph itself may be very large. We present a truly online strongly competitive paging algorithm in the access graph model that does not have any... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The analysis of a list-coloring algorithm on a random graph

    Publication Year: 1997, Page(s):204 - 212
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (692 KB)

    We introduce a natural k-coloring algorithm and analyze its performance on random graphs with constant expected degree c (Gn,p=cn/). For k=3 our results imply that almost all graphs with n vertices and 1.923 n edges are 3-colorable. This improves the lower bound on the threshold for random 3-colorability significantly and settles the last case of a long-standing open question of Bolloba... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Does parallel repetition lower the error in computationally sound protocols?

    Publication Year: 1997, Page(s):374 - 383
    Cited by:  Papers (11)  |  Patents (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (980 KB)

    Whether or not parallel repetition lowers the error has been a fundamental question in the theory of protocols, with applications in many different areas. It is well known that parallel repetition reduces the error at an exponential rate in interactive proofs and Arthur-Merlin games. It seems to have been taken for granted that the same is true in arguments, or other proofs where the soundness onl... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Tight bounds for depth-two superconcentrators

    Publication Year: 1997, Page(s):585 - 594
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (728 KB)

    We show that the minimum size of a depth-two N-superconcentrator is Θ(Nlog2N/loglogN). Before this work, optimal bounds were known for all depths except two. For the upper bound, we build superconcentrators by putting together a small number of disperser graphs; these disperser graphs are obtained using a probabilistic argument. We present two different methods for showing lower b... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.