Let f : π → π be a homeomorphism of the plane π. We define open sets P , called pruning fronts after the work of Cvitanović [C], for which it is possible to construct an isotopy H : π × [0, 1] → π with open support contained in ⋃ n∈Z f(P ) such that H(·, 0) = f(·) and H(·, 1) = fP (·), where fP is a homeomorphism under which every point of P is wandering. Applying this construction with f being...

Recently, simple dynamical systems as the 1-d maps on the interval, gained significant attention in the context of statistical physics and complex systems.The decay of correlations in these systems, can be characterized and measured by correlation functions.Thus, in the context of symbolic dynamics of the non-chaotic multifractal attractors (i.e. Feigenbaum attractors), another observable, the ...

In this paper we consider a Multi Carrier Code Division Multiplex (MC–CDM) scheme. At the receiver side the Maximum A Posteriori Symbol–by–Symbol Estimator (MAPSSE) is used for the detection of the CDM signal. Therefore the influence of the spreading factor on the overall Bit Error Rate (BER) is investigated. We concatenate the MAPSSE with the channel decoder which allows for iterative decoding...

This paper addresses the problem of equalization space-time codes with transmit diversity. We derive a symbol-by-symbol MAP equalizer/decoder for space-time coded signals over frequency selective channels. We describe a turbo equalization/decoding scheme where the results of the decoding are fed back to the equalizer. Simulation results show an improved equalizer performance due to the feedback.

We present results for pseudodifferential operators on Rd whose symbol a(·,ξ) is almost periodic (a.p.) for each ξ ∈ Rd and belongs to a Hörmander class Sm ρ,δ. We study a linear transformation a 7→ U(a) from a symbol a(x,ξ) to a frequency-dependent matrix U(a)(ξ)λ,λ′ , indexed by (λ,λ′) ∈ Λ×Λ where Λ is a countable set in Rd . The map a 7→ U(a) transforms symbols of a.p. pseudodifferential ope...

Recently, we have introduced the notion of the generalization of the shift map, that is, the generalized shift map, in the symbol space 2 Σ . In this paper we have proved some stronger chaotic properties of the generalized shift map. An example has been given in the last section.

Automatic separation of text and symbols from graphics in document image is one of the fundamental aims in graphics recognition. In maps, separation of text and symbols from graphics involves many challenges because the text and symbols frequently touch/overlap with graphical components. Sometimes the colors in a single character are gradually distributed which adds extra difficulty in text and...

Let N and P be smooth closed manifolds of dimensions n and p respectively. Given a Thom-Boardman symbol I, a smooth map f : N → P is called an Ω -regular map if and only if the Thom-Boardman symbol of each singular point of f is not greater than I in the lexicographic order. We will represent the group of all cobordism classes of Ω -regular maps of n-dimensional closed manifolds into P in terms...

Christian Weiß and Jens Berkmann Institute for Communications Engineering (LNT) Munich University of Technology (TUM) e-mail: Christian.Weiss,Jens.Berkmann @ei.tum.de The trellis of a finite abelian group code is locally (i.e., trellis section by trellis section) related to the trellis of the corresponding dual group code. This allows to express the update rules of the BCJR algorithm operating ...