A new approach for concatenation of codes is proposed. Only a part of data symbols is fed to an outer encoder whereas the remaining part is directly forwarded to an inner encoder. (For example the inner code can be intersymbol interference causing process .) Thus, only samples of data are encoded by the concatenated structure. During an iterative decoding procedure is improved reliability not o...

The local computation of Linial [FOCS’87] and Naor and Stockmeyer [STOC’93] concerns with the question of whether a locally definable distributed computing problem can be solved locally: more specifically, for a given local CSP whether a CSP solution can be constructed by a distributed algorithm using local information. In this paper, we consider the problem of sampling a uniform CSP solution b...

We present a novel technique for ray tracing geometry represented by points. Our approach makes it possible to render high quality ray traced images with global illumination using unstructured point–sampled data thus avoiding the time-consuming process of reconstructing the underlying surface or any topological information. Compared with previous point rendering methods, our approach allows for...

Introduction Implicit surfaces are a powerful shape description for many applications in computer graphics. An implicit surface is defined by a function f :R → R as the set of points satisfying f(p) = 0. Implicit representation becomes more effective when f is a signed distance function, i.e., when |f | gives the distance to the closest point on the surface and f is negative inside the object a...

Abstract—This paper deals with efficient quadrature formulas involving functions that are observed only at fixed sampling points. The approach that we develop is derived from efficient continuous quadrature formulas, such as Gauss-Legendre or Clenshaw-Curtis quadrature. We select nodes at sampling positions that are as close as possible to those of the associated classical quadrature and we upd...

Ravikanth Pappu Massachusetts Institute of Technology Media Laboratory Spatial Imaging Group 20 Ames Street Cambridge, Massachusetts 02139 E-mail: [email protected] Abstract. An novel algorithm for computing holographic fringe patterns based on nonuniform sampling is described. We show both analytically and via simulation that nonuniform sampling reduces the number of samples required to repr...

Timed automata can be studied in not only a dense-time setting but also a discrete-time setting. The most common example of discrete-time semantics is the so called sampled semantics (i.e., discrete semantics with a xed time granularity "). In the real-time setting, the universality problem is known to be undecidable for timed automata. In this work, we study the universality question for the l...