We introduce a novel algorithm for decoding turbo-like codes based on linear programming. We prove that for the case of Repeat-Accumulate (RA) codes, under the binary symmetric channel with a certain constant threshold bound on the noise, the error ...

In this paper we determine the computational complexity of the dynamic convex hull problem in the planar case. We present a data structure that maintains a finite set of n points in the plane under insertion and deletion of points in amortized O(log n) ...

Two decades ago, Megiddo and Dyer showed that linear programming in 2 and 3 dimensions (and subsequently, any constant number of dimensions) can be solved in lineartime. In this paper, we consider linear programming with at most k violations: finding a ...

In this paper we propose a definition for (honest verifier) quantum statistical zero-knowledge interactive proof systems and study the resulting complexity class, which we denote QSZKHV. We prove several facts regarding this class, including:The ...

In a wireless network, a basestation transmits data to mobiles at time-varying, mobile-dependent rates due to the ever changing nature of the communication channels. Inthis paper we consider a wireless system in which the channel conditions and data ...

We show that sets consisting of strings of high Kolmogorov complexity provide examples of sets that are complete for several complexity classes under probabilistic and non-uniform reductions. These sets are provably not complete under the usual many-one ...

Let P be a set of n points in \mathbb{R}^d. For any 1 \leqslant k \leqslant d, the outer k-radius of P, denoted by Rk (P), is the minimum, over all (d - k)-dimensional flats F, of \max _{p\varepsilon P} d(p,f), where d (p, F) is the Euclidean distance ...

For a CNF_\tau, let wb(\tau ) be the bronch-width of its underlying hypergraph. In this paper we design an algorithm for solving SAT in time n^{0(1)} 2^0 (wb(\tau )). This in particular implies a polynomial algorithm for testing satisfiability on ...

We present the first constant-factor approximation algorithm for network design with multiple commodities and economies of scale. We consider the rent-or-buy problem, a type of multicommodity buy-at-bulk network design in which there are two ways to ...

Karger, Motwani and Sudan (JACM 1998) introduced the notion of a vector coloring of a graph. In particular they show that every k-colorable graph is also vector k-colorable, and that for constant k, graphs that are vector k-colorable can be colored by ...

We show that Graph Isomorphism is in the complexity class SPP, and hence it is in \oplusP (in fact, it is in ModkP for each k \geqslant 2). We derive this result as a corollary of a more general result: we show that a generic problem FIND-GROUP has an ...

We develop a parameterized complexity theory for counting problems. As the basis of this theory, we introduce a hierarchy of parameterized counting complexity classes #W[t], for t \geqslant 1 , that corresponds to Downey and Fellows's W-hierarchy [12] ...

We give a fully polynomial time approximation scheme (FPTAS) for the optimum fractional solution to the Steiner forest problem. This can easily be generalized to obtain an FPTAS for a hitting set problem on a collection of clutters. We also identify ...

Self-assembly, the process by which objects autonomously come together to form complex structures, is omnipresent in the physical world. A systematic study of self-assembly as a mathematical process has been initiated. The individual components are ...

We obtain several new dynamic algorithms for maintaining the transitive closure of a directed graph, and several other algorithms for answering reachability queries without explicitly maintaining a transitive closure matrix. Among our algorithms are:(i) ...

We consider the problem of sampling almost uniformly from the set of contingency tables with given row and column sums, when the number of rows is a constant. Cryan and Dyer [3] have recently given a fully polynomial randomized approximation scheme (...

Randomization is vital in cryptography: secret keys should be randomly generated and most cryptographic primitives (e.g., encryption) must be probabilistic. As a common abstraction, it is assumed that there is a source of truly random bits available to ...

We prove a quasi-polynomial lower bound on the size of bounded-depth Frege proofs of the pigeonhole principle PHP_n^m where m = (1 + {1 \mathord{\left/ {\vphantom {1 {poly\log n)n}}} \right. \kern-\nulldelimiterspace} {poly\log n)n}}. This lower bound ...