The best known output-sensitive sequential algorithm for computing the viewshed on a polyhedral terrain from a given viewpoint was proposed by Katz, Overmars, and Sharir 10 , and achieves time complexity O((k + nn(n)) log n) where n and k are the input and output sizes respectively, and () is the inverse Ackermann's function. In this paper, we present a parallel algorithm that is based on the w...

We show that, by combining an existing compression boosting technique with the wavelet tree data structure, we are able to design a variant of the FM-index which scales well with the size of the input alphabet Σ. The size of the new index built on a string T [1, n] is bounded by nHk(T )+O ( (n log log n)/ log|Σ| n ) bits, where Hk(T ) is the k-th order empirical entropy of T . The above bound h...

A pruned variant of polar coding is proposed for binary erasure channel (BEC). Fix any BEC. For sufficiently small ε > 0, we construct a series capacity achieving codes with block length N = ε-4.9, code rate R Capacity - O(ε), error probability P ε, and encoding decoding time complexity bC O(log|log ε|) per information bit. The given per-bit log-logarithmic in N, R, P. Beyond BEC, there general...

This paper describes the design of a currentmode single-input multiple-output (SIMO) universal filter based on the log-domain filtering concept. The circuit is a direct realization of a first-order differential equation for obtaining the lossy integrator circuit. Lossless integrators are realized by log-domain lossy integrators. The proposed filter comprises only two grounded capacitors and twe...

In [IPL2005], Frandsen and Miltersen improved bounds on the circuit size L(n) of the hardest Boolean function on n input bits: for some constant c > 0: ( 1 + log n n − c n ) 2 n ≤ L(n) ≤ ( 1 + 3 logn n + c n ) 2 n . In this note, we announce a modest improvement on the lower bound: for some constant c > 0 (and for any sufficiently large n), L(n) ≥ ( 1 + 2 log n n − c n ) 2 n .

We propose an approach for modularizing P-log programs and corresponding compositional semantics based on conditional probability measures. We do so by resorting to Oikarinen and Janhunen’s definition of a logic program module and extending it to P-log by introducing the notions of input random attributes and output literals. For answering to P-log queries our method does not imply calculating ...

It is well known that the containment problem (as well as the equivalence problem) for semilinear sets is log-complete in Πp2. In this paper, we show that already the containment problem for linear sets is log-hard (and therefore also log-complete) in Πp2. This holds even when we use a unary encoding for the numerical input parameters or when we restrict the problem to 1-dimensional linear sets...

We propose an approach for modularizing P-log programs and corresponding compositional semantics based on conditional probability measures. We do so by resorting to Oikarinen and Janhunen’s definition of a logic program module and extending it to P-log by introducing the notions of input random attributes and output literals. For answering to P-log queries our method does not imply calculating ...

We consider the two-party quantum communication complexity of the bit version of the pointer chasing problem, originally studied by Klauck, Nayak, Ta-Shma and Zuckerman [KNTZ01]. We show that in any quantum protocol for this problem, the two players must exchange Ω( n k4 ) qubits. This improves the previous best bound of Ω( n 22 O(k) ) in [KNTZ01], and comes significantly closer to the best upp...

Given an input consisting of an n-vertex convex polygon with k hole vertices or an n-vertex planar straight line graph (PSLG) with k holes and/or reflex vertices inside the convex hull, the parameterized minimum number convex partition (MNCP) problem asks for a partition into a minimum number of convex pieces. We give a fixedparameter tractable algorithm for this problem that runs in the follow...