1,372,055 research outputs found
Sergei Kuznetsov Interview November 8, 1994
No full textNOTE: to view these items please visit http://dynkincollection.library.cornell.eduInterview conducted by Eugene Dynkin with Sergei E. Kuznetsov on November 8, 1994 , this file has had a portion removed from the middle because of a phone call Kuznetsov received
An explicit Kuznetsov-Muravitsky enrichment
No full textAn embedding of arbitrary Heyting algebra H into a reduct from the variety of
Kuznetsov-Muravitsky algebras is constructed. An algebraic proof is given that
this reduct belongs to the variety of Heyting algebras generated by H
Backlund transformations for many-body systems related to KdV
No full textWe present Backlund transformations (BTs) with parameter for certain classical integrable n-body systems, namely the many-body generalised Henon-Heiles, Garnier and Neumann systems. Our construction makes use of the fact that all these systems may be obtained as particular reductions (stationary or restricted flows) of the KdV hierarchy; alternatively they may be considered as examples of the reduced sl(2) Gaudin magnet. The BTs provide exact time-discretizations of the original (continuous) systems, preserving the Lax matrix and hence all integrals of motion, and satisfy the spectrality property with respect to the Backlund parameter
Marangoni convection of a viscous fluid over a vibrating plate
No full textThis research presents a new insight into Marangoni convection through investigating, both numerically and analytically, the surface tension driven instability activated by a coupled effect of a vibrating plate and viscous dissipation. A horizontal, thin fluid layer is bounded from below by an impermeable, adiabatic plate that vibrates in the horizontal direction. The upper boundary is modelled by a free surface subject to a thermal boundary condition of the third kind (Robin). The internal heat generation due to viscous dissipation yields a vertical, potentially unstable temperature gradient. The linear stability analysis of the stationary terms of the basic state is performed. The perturbed flow, in the form of plane waves, is superimposed onto the basic state. The obtained system of ordinary differential equations is solved numerically by means of the Runge-Kutta method coupled with the shooting method. For the two limiting cases, the isothermal upper boundary and adiabatic upper boundary, the analytical solutions of the eigenvalue problem are obtained. The values of the critical parameter, which identifies the threshold for the onset of Marangoni convection, are presented
Anatoly Kuznetsov, Author of Babi Yar: The History of the Book and the Fate of the Author
No full textThis Introduction to the special issue devoted to Anatoly Kuznetsov, author of Babi Yar: A Document in the Form of a Novel, dwells on the different aspects of the book’s importance, surveys the life of the author as intertwined with the history of this book, suggests a way of reading his other work in the light of Babi Yar, and notes the contributions of the articles collected in this issue
Software Implementation of Data Hiding in Vector Images
No full textThe work conducted a study of methods of concealing data into vector images, the features of their mathematical models, which make it possible to perform steganographic transformations for concealing and extracting information sequences. The purpose of the work was to analyze existing methods of concealing data into geometric elements of vector graphics, in particular the Bezier curves of the third order, the own programming implementation in the programming language JavaScript. Developed software implementation allows performing the operations of hiding and extracting messages in SVG files
Data hiding in vector images
No full textThe suggested in the last few years methods of data hiding in the vector images are considered in the article. The individual elements of a vector graphic are described through special mathematical objects such as points, lines, curves of first and second order, Bezier curves, nodes, tangent lines, control points, etc. Such objects are being used for data concealing. The main aim lies in ensuring affine transformations resistance, and vector graphics allow its implementation. There are a few methods of data hiding, that are considered and programmable implemented in the article. The performed experimental research proves, that used techniques indeed allow to achieve high resistance indicators to affine transformations. Moreover, the suggested implementation is cross-platform because created with JavaScript program language. That means that scripts can be run on different types of platforms and browsers. Thus, developed implementation can be used in the future as a framework both for web-client applications and backend of more complex and professional tasks
Message Concealing in Vector Images
No full textVarious steganography techniques are used to conceal information. Typically, information is hidden in images, audio and video files, text documents, etc. We are considering vector images consisting of various mathematical objects (points, lines, curves of first and second-order curves, the Bezier curves, nodes, tangents, control points, etc.). The techniques of information hiding change those mathematical objects, for instance, in the way of encoding the basic points' coordinates. In the article, two methods (bit and pattern) are considered and being experimentally tested in order to track the possible destruction of embedded data. To do this, affine transformations are used and our experiments consist of repeated attempts to destroy information due to the use of various affine transformations with different parameters. The results demonstrate that vector images can indeed be used to conceal information, but the resistance against certain affine attacks is not always high
Analysis of pattern formation in chaos of coupled bistable elements
No full textOne of the most complex problems of nonlinear dynamics is the investigation of collective dynamics of ensembles consisting of a large number of coupled elements. A number of investigations were carried out for linear coupling of diffusion (difference) type. Recently, based on successful investigations of neurobiological objects [Abarbanel et al., 1996], an interest has grown in the study of dynamics of ensembles with nonlinear, nondiffusion type of coupling. In this paper we address pattern formation in a chain of bistable elements so coupled [Kuznetsov & Shalfeev, 2000]
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