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Foundations of Computer Science, 1998. Proceedings. 39th Annual Symposium on

Date 8-11 Nov. 1998

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Displaying Results 1 - 25 of 81
  • Proceedings 39th Annual Symposium on Foundations of Computer Science (Cat. No.98CB36280)

    Publication Year: 1998
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  • Geometric computation and the art of sampling (tutorial)

    Publication Year: 1998 , Page(s): 2
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (7 KB)  

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  • A tutorial on theoretical issues in probabilistic artificial intelligence

    Publication Year: 1998 , Page(s): 4
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  • Author index

    Publication Year: 1998 , Page(s): 744 - 745
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    Freely Available from IEEE
  • Quantum lower bounds by polynomials

    Publication Year: 1998 , Page(s): 352 - 361
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (180 KB)  

    We examine the number T of queries that a quantum network requires to compute several Boolean functions on {0,1}N in the black-box model. We show that, in the black-box model, the exponential quantum speed-up obtained for partial functions (i.e. problems involving a promise on the input) by Deutsch and Jozsa and by Simon cannot be obtained for any total function: if a quantum algorithm ... View full abstract»

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  • Optimal time-space trade-offs for sorting

    Publication Year: 1998 , Page(s): 264 - 268
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (92 KB)  

    We study the fundamental problem of sorting in a sequential model of computation and in particular consider the time-space trade-off (product of time and space) for this problem. P. Beame (1991) has shown a lower bound of Ω(n2) for this product leaving a gap of a logarithmic factor up to the previously best known upper bound of O(n2 log n) due to G.N. Frederickson (1987... View full abstract»

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  • A factor 2 approximation algorithm for the generalized Steiner network problem

    Publication Year: 1998 , Page(s): 448 - 457
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (132 KB)  

    We present a factor 2 approximation algorithm for finding a minimum-cost subgraph having at least a specified number of edges in each cut. This class of problems includes, among others, the generalized Steiner network problem, which is also known as the survivable network design problem. Our algorithm first solves the linear relaxation of this problem, and then iteratively rounds off the solution.... View full abstract»

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  • A characterization of NC by tree recurrence

    Publication Year: 1998 , Page(s): 716 - 724
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    We show that a boolean valued function is in NC if it is defined by ramified schematic recurrence over trees. This machine-independent characterization uses no initial functions other than basic tree operations, and no bounding conditions on the recurrence. Aside from its technical interest, our result evidences the foundational nature of NC, thereby illustrating the merits of implicit (i.e. machi... View full abstract»

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  • On the single-source unsplittable flow problem

    Publication Year: 1998 , Page(s): 290 - 299
    Cited by:  Papers (5)  |  Patents (5)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (172 KB)  

    Let G=(V,E) be a capacitated directed graph with a source s and k terminals ti with demands di, 1⩽i⩽k. We would like to concurrently route every demand on a single path from s to the corresponding terminal without violating the capacities. There are several interesting and important variations of this unsplittable flow problem. If the necessary cut condition is satisf... View full abstract»

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  • Faster algorithms for string matching problems: matching the convolution bound

    Publication Year: 1998 , Page(s): 166 - 173
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (132 KB)  

    In this paper we give a randomized O(nlogn)-time algorithm for the string matching with don't cares problem. This improves the Fischer-Paterson bound from 1974 and answers the open problem posed (among others) by Weiner and Galil. Using the same technique, we give an O(nlogn)-time algorithm for other problems, including subset matching, tree pattern matching, (general) approximate threshold matchi... View full abstract»

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  • Lower bounds for zero knowledge on the Internet

    Publication Year: 1998 , Page(s): 484 - 492
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (148 KB)  

    We consider zero knowledge interactive proofs in a richer, more realistic communication environment. In this setting, one may simultaneously engage in many interactive proofs, and these proofs may take place in an asynchronous fashion. It is known that zero-knowledge is not necessarily preserved in such an environment; we show that for a large class of protocols, it cannot be preserved. Any 4 roun... View full abstract»

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  • Semidefinite relaxations for parallel machine scheduling

    Publication Year: 1998 , Page(s): 472 - 481
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (136 KB)  

    We consider the problem of scheduling unrelated parallel machines so as to minimize the total weighted completion time of jobs. Whereas the best previously known approximation algorithms for this problem are based on LP relaxations, we give a 3/2-approximation algorithm that relies on a convex quadratic programming relaxation. For the special case of two machines we present a further improvement t... View full abstract»

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  • The minimum equivalent DNF problem and shortest implicants

    Publication Year: 1998 , Page(s): 556 - 563
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (124 KB)  

    We prove that the Minimum Equivalent DNF problem is Σ2 p-complete, resolving a conjecture due to L.J. Stockmeyer (1976). The proof involves as an intermediate step a variant of a related problem in logic minimization, namely, that of finding the shortest implicant of a Boolean function. We also obtain certain results concerning the complexity of the shortest implicant p... View full abstract»

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  • Which problems have strongly exponential complexity?

    Publication Year: 1998 , Page(s): 653 - 662
    Cited by:  Papers (17)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (168 KB)  

    For several NP-complete problems, there have been a progression of better but still exponential algorithms. In this paper we address the relative likelihood of sub-exponential algorithms for these problems. We introduce a generalized reduction which we call sub-exponential reduction family (SERF) that preserves sub-exponential complexity. We show that Circuit-SAT is SERF-complete for all NP-search... View full abstract»

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  • A tight characterization of NP with 3 query PCPs

    Publication Year: 1998 , Page(s): 8 - 17
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (168 KB)  

    It is known that there exists a PCP characterization of NP where the verifier makes 3 queries and has a one-sided error that is bounded away from 1; and also that 2 queries do not suffice for such a characterization. Thus PCPs with 3 queries possess non-trivial verification power and motivate the task of determining the lowest error that can be achieved with a 3-query PCP. Recently, Hastad (1997) ... View full abstract»

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  • Heuristics for finding large independent sets, with applications to coloring semi-random graphs

    Publication Year: 1998 , Page(s): 674 - 683
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (160 KB)  

    We study a semi-random graph model for finding independent sets. For α>0, an n-vertex graph with an independent set S of site αn is constructed by blending random and adversarial decisions. Randomly and independently with probability p, each pair of vertices, such that one is in S and the other is not, is connected by an edge. An adversary can then add edges arbitrarily (provided th... View full abstract»

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  • A unified superfast algorithm for boundary rational tangential interpolation problems and for inversion and factorization of dense structured matrices

    Publication Year: 1998 , Page(s): 192 - 201
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (156 KB)  

    The classical scalar Nevanlinna-Pick interpolation problem has a long and distinguished history, appearing in a variety of applications in mathematics and electrical engineering. There is a vast literature on this problem and on its various far reaching generalizations. It is widely known that the now classical algorithm for solving this problem proposed by Nevanlinna in 1929 can be seen as a way ... View full abstract»

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  • An improved exponential-time algorithm for k-SAT

    Publication Year: 1998 , Page(s): 628 - 637
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (184 KB)  

    We propose and analyze a simple new algorithm for finding satisfying assignments of Boolean formulae in conjunctive normal form. The algorithm, ResolveSat, is a randomized variant of the DDL procedure by M. Davis et al. (1962) or Davis-Putnam procedure. Rather than applying the DLL procedure to the input formula F, however; ResolveSat enlarges F by adding additional clauses using limited resolutio... View full abstract»

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  • Fast Monte-Carlo algorithms for finding low-rank approximations

    Publication Year: 1998 , Page(s): 370 - 378
    Cited by:  Papers (22)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (120 KB)  

    In several applications, the data consists of an m×n matrix A and it is of interest to find an approximation D of a specified rank k to A where, k is much smaller than m and n. Traditional methods like the Singular Value Decomposition (SVD) help us find the “best” such approximation. However, these methods take time polynomial in m, n which is often too prohibitive. In this paper... View full abstract»

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  • Satisfiability of word equations with constants is in exponential space

    Publication Year: 1998 , Page(s): 112 - 119
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (124 KB)  

    In this paper we study solvability of equations over free semigroups, known as word equations, particularly G.S. Makanin's algorithm (1977), a general procedure to decide if a word equation has a solution. The upper bound time-complexity of Makanin's original decision procedure was quadruple exponential in the length of the equation, as shown by Jaffar. A. Koscielski and L. Pacholski (1996) reduce... View full abstract»

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  • Time-space tradeoffs for branching programs

    Publication Year: 1998 , Page(s): 254 - 263
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (200 KB)  

    We obtain the first non-trivial time-space tradeoff lower bound for functions f: {0,1}n→{0,1} on general branching programs by exhibiting a Boolean function f that requires exponential size to be computed by any branching program of length (1+ε)n, for some constant ε>0. We also give the first separation result between the syntactic and semantic read-k models for k>1... View full abstract»

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  • Oblivious transfer with a memory-bounded receiver

    Publication Year: 1998 , Page(s): 493 - 502
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (192 KB)  

    We propose a protocol for oblivious transfer that is unconditionally secure under the sole assumption that the memory size of the receiver is bounded. The model assumes that a random bit string slightly larger than the receiver's memory is broadcast (either by the sender or by a third party). In our construction, both parties need memory of size in θ(n2-2α) for some α&... View full abstract»

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  • Faster and simpler algorithms for multicommodity flow and other fractional packing problems

    Publication Year: 1998 , Page(s): 300 - 309
    Cited by:  Papers (99)  |  Patents (10)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (176 KB)  

    This paper considers the problem of designing fast, approximate, combinatorial algorithms for multicommodity flows and other fractional packing problems. We provide a different approach to these problems which yields faster and much simpler algorithms. Our approach also allows us to substitute shortest path computations for min-cost flow computations in computing maximum concurrent flow and min-co... View full abstract»

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  • Algorithms to tile the infinite grid with finite clusters

    Publication Year: 1998 , Page(s): 137 - 145
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (148 KB)  

    We say that a subset T of Z2, the two dimensional infinite grid, tiles Z2 if we can cover Z2 with non-overlapping translates of T. No algorithm is known to decide whether a finite T⊆Z2 tiles Z2. Here we present two algorithms, one for the case when |T| is prime, and another for the case when |T|=4. Both algorithms generalize to the case, ... View full abstract»

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  • Tseitin's tautologies and lower bounds for Nullstellensatz proofs

    Publication Year: 1998 , Page(s): 648 - 652
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (148 KB)  

    We use the known linear lower bound for Tseitin's tautologies for establishing linear lower bounds on the degree of Nullstellensatz proofs (in the usual boolean setting) for explicitly constructed systems of polynomials of a constant (in our construction 6) degree. It holds over any field of characteristic distinct from 2. Previously, a linear lower bound was proved for an explicitly constructed s... View full abstract»

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