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Spline Subdivision Schemes for Compact Sets. A Survey

Dyn, Nira, Farkhi, Elza (2002)

Serdica Mathematical Journal

Dedicated to the memory of our colleague Vasil Popov January 14, 1942 – May 31, 1990 * Partially supported by ISF-Center of Excellence, and by The Hermann Minkowski Center for Geometry at Tel Aviv University, IsraelAttempts at extending spline subdivision schemes to operate on compact sets are reviewed. The aim is to develop a procedure for approximating a set-valued function with compact images from a finite set of its samples. This is motivated by the problem of reconstructing a 3D object from...

Spontaneous clustering in theoretical and some empirical stationary processes*

T. Downarowicz, Y. Lacroix, D. Léandri (2010)

ESAIM: Probability and Statistics

In a stationary ergodic process, clustering is defined as the tendency of events to appear in series of increased frequency separated by longer breaks. Such behavior, contradicting the theoretical “unbiased behavior” with exponential distribution of the gaps between appearances, is commonly observed in experimental processes and often difficult to explain. In the last section we relate one such empirical example of clustering, in the area of marine technology. In the theoretical part of the paper...

Stability and throughput improvement for multichannel CSMA and CSMA/CD protocols with optimal bandwidth allocation

Ioannis E. Pountourakis (2000)

Kybernetika

This paper examines appropriate protocols for high speed multiple access communication systems where the bandwidth is divided into two separate asymmetric channels. Both channels operate using slotted non-persistent CSMA or CSMA/CD techniques. Free stations access the first channel while all retransmissions occur in the second channel. We define the stability regions and the rules for optimal bandwidth allocation among the two channels for improvement of the system performance in case of infinite...

Stability type results concerning the fundamental equation of information of multiplicative type

Eszter Gselmann (2009)

Colloquium Mathematicae

The paper deals with the stability of the fundamental equation of information of multiplicative type. It is proved that the equation in question is stable in the sense of Hyers and Ulam under some assumptions. This result is applied to prove the stability of a system of functional equations that characterizes the recursive measures of information of multiplicative type.

Stochastic control optimal in the Kullback sense

Jan Šindelář, Igor Vajda, Miroslav Kárný (2008)

Kybernetika

The paper solves the problem of minimization of the Kullback divergence between a partially known and a completely known probability distribution. It considers two probability distributions of a random vector ( u 1 , x 1 , ... , u T , x T ) on a sample space of 2 T dimensions. One of the distributions is known, the other is known only partially. Namely, only the conditional probability distributions of x τ given u 1 , x 1 , ... , u τ - 1 , x τ - 1 , u τ are known for τ = 1 , ... , T . Our objective is to determine the remaining conditional probability distributions of u τ given u 1 , x 1 , ... , u τ - 1 , x τ - 1 such...

Stochastic domination for iterated convolutions and catalytic majorization

Guillaume Aubrun, Ion Nechita (2009)

Annales de l'I.H.P. Probabilités et statistiques

We study how iterated convolutions of probability measures compare under stochastic domination. We give necessary and sufficient conditions for the existence of an integer n such that μ*n is stochastically dominated by ν*n for two given probability measures μ and ν. As a consequence we obtain a similar theorem on the majorization order for vectors in Rd. In particular we prove results about catalysis in quantum information theory.

Stochastic signal codification and sigma transform.

Luis Basañez Villaluenga, Nadal Batle Nicolau, Gabriel Ferraté Pascual, Josep Grané Manlleu, Enric Trillas (1983)

Stochastica

In the last years, a relation between bounded real functions of one variable and two-valued probabilistic functions defined on the complex plane has been established through the introduction of the Sigma-Transform concept.The paper presents an extension of the concept of Sigma-Transform, giving rise to the diagonal Sigma-Transform and the Striped Sigma-Transform which, when combined, allow a formal treatment of the Multichannel Stochastic Signal Codification. An application of the method to error...

Structure of unitary groups over finite group rings and its application

Jizhu Nan, Yufang Qin (2010)

Czechoslovak Mathematical Journal

In this paper, we determine all the normal forms of Hermitian matrices over finite group rings R = F q 2 G , where q = p α , G is a commutative p -group with order p β . Furthermore, using the normal forms of Hermitian matrices, we study the structure of unitary group over R through investigating its BN-pair and order. As an application, we construct a Cartesian authentication code and compute its size parameters.

Study of the Information Security of File Objects under Information Attacks with a Record of Effect of the Methods of Compression

Polimirova-Nickolova, Dimitrina (2008)

Serdica Journal of Computing

This report examines important issues pertaining to the different ways of affecting the information security of file objects under information attacks through methods of compression. Accordingly, the report analyzes the three-way relationships which may exist among a selected set of attacks, methods and objects. Thus, a methodology is proposed for evaluation of information security, and a coefficient of information security is created. With respects to this coefficient, using different criteria...

Su una generalizzazione della nozione di diramatività in teoria dell'informazione.

C. Bertoluzza, I. Bonzani (1983)

Stochastica

The notion of g-locality was introduced in order to generalize the branching one. This notion seems to represent the characteristic property of the entropies which can be utilized in the inquiring processes.In this paper we have characterized all the g-local entropies by determining the whole class of the locality laws.

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