Date 1919 Nov. 2002
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Proceedings 43rd Annual IEEE Symposium on Foundations of Computer Science
Publication Year: 2002 PDF (327 KB) 
Learning intersections and thresholds of halfspaces
Publication Year: 2002, Page(s):177  186
Cited by: Papers (8)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 polynomialweight halfspaces under any distribution. As special cases of these results we obtain algorithms for learning inte... View full abstract»

Erratum to "Vickrey pricing and shortest paths: What is an edge worth?"
Publication Year: 2002, Page(s): 809
Cited by: Papers (1) 
Author index
Publication Year: 2002, Page(s):811  813 PDF (177 KB) 
PAC=PAExact and other equivalent models in learning
Publication Year: 2002, Page(s):167  176The 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/ω(poly) for any poly). This model allows studying (almost) exact learnability of infinite classes and is in some sense ana... View full abstract»

Load balancing with memory
Publication Year: 2002, Page(s):799  808
Cited by: Papers (10)  Patents (4)A standard load balancing model considers placing n balls into n bins by choosing d possible locations for each ball independently and uniformly at random and sequentially placing each in the least loaded of its chosen bins. It is well known that allowing just a small amount of choice (d = 2) greatly improves performance over random placement (d = 1). In this paper, we show that similar performanc... View full abstract»

Packing 2dimensional bins in harmony
Publication Year: 2002, Page(s):490  499
Cited by: Papers (6)We consider 2Dimensional (Finite) Bin Packing (2BP), which is one of the most important generalizations of the wellknown Bin Packing (BP) and calls for orthogonally packing a given set of rectangles (that cannot be rotated) into the minimum number of unit size squares. There are many open questions concerning the approximability of 2BP, whereas the situation for the 2stage case, in which the it... View full abstract»

Nash equilibria in competitive societies, with applications to facility location, traffic routing and auctions
Publication Year: 2002, Page(s):416  425
Cited by: Papers (32)We consider the following class of problems. The value of an outcome to a society is measured via a submodular utility function (submodularity has a natural economic interpretation: decreasing marginal utility). Decisions, however, are controlled by noncooperative agents who seek to maximise their own private utility. We present, under basic assumptions, guarantees on the social performance of Na... View full abstract»

An inverseAckermann style lower bound for the online minimum spanning tree verification problem
Publication Year: 2002, Page(s):155  163We consider the problem of preprocessing an edgeweighted 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 ∪ {e}? Whereas the offline minimum spanning tree verification problem admits a lovely linear time solution, we demonstrate an inherent inverseAckermann type tradeoff in the online MST verification problem. In pa... View full abstract»

Constantround cointossing with a man in the middle or realizing the shared random string model
Publication Year: 2002, Page(s):345  355
Cited by: Papers (15)We present the first constantround nonmalleable commitment scheme and the first constantround nonmalleable zeroknowledge argument system, as defined by Dolev, Dwork and Naor (1991). Previous constructions either used a nonconstant number of rounds, or were only secure under stronger setup assumptions. An example of such an assumption is the shared random string model where we assume all part... View full abstract»

Forbidden information
Publication Year: 2002, Page(s):761  765
Cited by: Papers (1)There appears to be a gap between usual interpretations of Godel Theorem and what is actually proven. Closing this gap does not seem obvious and involves complexity theory. (This is unrelated to, well studied before, complexity quantifications of the usual Godel effects.) Similar problems and answers apply to other unsolvability results for tasks where required solutions are not unique, such as, e... View full abstract»

Concurrent zero knowledge with logarithmic roundcomplexity
Publication Year: 2002, Page(s):366  375
Cited by: Papers (13)We show that every language in NP has a (blackbox) concurrent zeroknowledge proof system using O˜(log n) rounds of interaction. The number of rounds in our protocol is optimal, in the sense that any language outside BPP requires at least Ω˜(log n) rounds of interaction in order to be proved in blackbox concurrent zeroknowledge. The zeroknowledge property of our main protocol... View full abstract»

On random symmetric travelling salesman problems
Publication Year: 2002, Page(s):789  798Let the edges of the complete graph K_{n} be assigned independent uniform [0,1] random edge weights. Let Z_{TSP} and Z_{2FAC} be the weights of the minimum length travelling salesman tour and minimum weight 2factor respectively. We show that whp^{1} Z_{TSP}Z_{2FAC}=(1). The proof is via the analysis of a polynomial time algorithm that finds a tou... View full abstract»

Optimal system of loops on an orientable surface
Publication Year: 2002, Page(s):627  636
Cited by: Papers (8)Every compact orientable boundaryless surface ℳ can be cut along simple loops with a common point υ_{0}, pairwise disjoint except at υ_{0}, so that the resulting surface is a topological disk; such a set of loops is called a fundamental system of loops for ℳ. The resulting disk is a polygon in which the edges are pairwise identified on the surface; it is called ... View full abstract»

Small induceduniversal graphs and compact implicit graph representations
Publication Year: 2002, Page(s):53  62
Cited by: Papers (2)We show that there exists a graph G with n · 2^{O(log* n)} nodes, where any forest with n nodes is a nodeinduced subgraph of G. Furthermore, the result implies the existence of a graph with n^{k}2^{O(log* n)} nodes that contains all nnode graphs of fixed arboricity k as nodeinduced subgraphs. We provide a lower bound of Ω(n^{k}) for the size of such ... View full abstract»

Covering problems with hard capacities
Publication Year: 2002, Page(s):481  489
Cited by: Papers (7)  Patents (1)We consider the classical vertex cover and set cover problems with the addition of hard capacity constraints. This means that a set (vertex) can only cover a limited number of its elements (adjacent edges) and the number of available copies of each set (vertex) is bounded. This is a natural generalization of the classical problems that also captures resource limitations in practical scenarios. We ... View full abstract»

Auctions with severely bounded communication
Publication Year: 2002, Page(s):406  415
Cited by: Papers (4)We study auctions with severe bounds on the communication allowed: each bidder may only transmit t bits of information to the auctioneer. We consider both welfaremaximizing and revenuemaximizing auctions under this communication restriction. For both measures, we determine the optimal auction and show that the loss incurred relative to unconstrained auctions is mild. We prove unsurprising proper... View full abstract»

Implicit Btrees: New results for the dictionary problem
Publication Year: 2002, Page(s):145  154
Cited by: Papers (1)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»

A constantfactor approximation algorithm for the multicommodity rentorbuy problem
Publication Year: 2002, Page(s):333  342
Cited by: Papers (10)We present the first constant factor approximation algorithm for network design with multiple commodities and economies of scale. We consider the rentorbuy problem, a type of multicommodity buyatbulk network design in which there are two ways to install capacity on any given edge. Capacity can be rented, with cost incurred on a perunit of capacity basis, or bought, which allows unlimited use ... View full abstract»

Kolmogorov's structure functions with an application to the foundations of model selection
Publication Year: 2002, Page(s):751  760
Cited by: Papers (4)Kolmogorov (1974) proposed a nonprobabilistic approach to statistics, an individual combinatorial relation between the data and its model. We vindicate, for the first time, the rightness of the original "structure function", proposed by Kolmogorov: minimizing the datatomodel code length (finding the ML estimator or MDL estimator), in a class of contemplated models of prescribed maximal (Kolmogo... View full abstract»

Breaking the O(n^{1}(2k1)/) barrier for informationtheoretic Private Information Retrieval
Publication Year: 2002, Page(s):261  270
Cited by: Papers (25)  Patents (2)Private information retrieval (PIR) protocols allow a user to retrieve a data item from a database while hiding the identity of the item being retrieved. Specifically, in informationtheoretic, kserver PIR protocols the database is replicated among k servers, and each server learns nothing about the item the user retrieves. The cost of such protocols is measured by the communication complexity of... View full abstract»

Satisfiability, branchwidth and Tseitin tautologies
Publication Year: 2002, Page(s):593  603
Cited by: Papers (8)For a CNF τ, let w_{b}(τ) be the branchwidth of its underlying hypergraph. In this paper we design an algorithm for solving SAT in time n^{O(1)}2^{O(w(b)(τ))}. This in particular implies a polynomial algorithm for testing satisfiability on instances with treewidth O(log n). Our algorithm is a modification of the width based automated theorem prover (WBATP) whi... View full abstract»

A dichotomy theorem for constraints on a threeelement set
Publication Year: 2002, Page(s):649  658
Cited by: Papers (16)The Constraint Satisfaction Problem (CSP) provides a common framework for many combinatorial problems. The general CSP is known to be NPcomplete; however, certain restrictions on the possible form of constraints may affect the complexity, and lead to tractable problem classes. There is, therefore, a fundamental research direction, aiming to separate those subclasses of the CSP which are tractable... View full abstract»

Generalized compact knapsacks, cyclic lattices, and efficient oneway functions from worstcase complexity assumptions
Publication Year: 2002, Page(s):356  365
Cited by: Papers (5)We study a generalization of the compact knapsack problem for arbitrary rings: given m = O(log n) ring elements a_{1}, . . . , a_{m} ∈ R and a target value b ∈ R, find coefficients x_{1}, . . . , x_{m} ∈ X (where X is a subset of R of size 2^{n}) such that Σa_{i}x_{i} = b. The computational complexity of this problem depe... View full abstract»

The asymptotic order of the random kSAT threshold
Publication Year: 2002, Page(s):779  788
Cited by: Papers (9)Form a random kSAT formula on n variables by selecting uniformly and independently m=rn clauses out of all 2^{k} (_{k}^{n}) possible kclauses. The satisfiability threshold conjecture asserts that for each k there exists a constant r_{k} such that, as n tends to infinity, the probability that the formula is satisfiable tends to 1 if r
k and to 0 if r>r... View full abstract»