Geodesic

Volume 28 (2016) no. 1

Sommaire

Conjugacy word problem in the tree product of free groups with a cyclic amalgamation
p. 3-18
Steganographic capacity for one-dimensional Markov cover} \runningtitle{Steganographic capacity for one-dimensional Markov cover} \author*[1]{Valeriy A. Voloshko} \runningauthor{V.\,A. Voloshko} \affil[1]{ Belarusian State University, e-mail: valeravoloshko@yandex.ru} \abstract{For shift-invariant probability measures on the set of infinite two-sided binary sequences (one-dimensional covers) we introduce the notion of capacity as a maximum portion of embedded into the cover uniformly distributed (purely random) binary sequence (message) that admits special correction of the cover restoring its distribution up to distribution of $n$-tuples (subwords of some fixed length $n$). ``Special correction'' is carried out using the proposed new algorithm that changes some of the cover's symbols not occupied by embedded message. The features of the introduced capacity are examined for the Markov cover. In particular, we show how capacity may be significantly increased by weakening of the standard constraint that positions for message embedding have to be chosen by independent unfair coin tosses. Experimental results are presented for correction of real steganographic covers after LSB-embedding.} \keywords{binary sequence, shift-invariant measure, steganography, capacity
p. 19-43
Independent sets in graphs
p. 44-77
Successive partition of edges of bipartite graph into matchings
p. 78-86
Tests of contact closure for contact circuits
p. 87-100
Application of Hadamard product to some combinatorial and probabilistic problems
p. 101-112
On asymptotics of branching processes with immigration
p. 113-122
The second coordinate sequence of the MP-LRS over nontrivial Galois ring of an odd characteristic
p. 123-149
Extension of the Rissanen algorithm to the factorization of block-Hankel matrices for solving systems of linear equations
p. 150-155