326,244 research outputs found
Optimizing the Local Search Algorithm for Generating S-Boxes
No full textNonlinear substitutions (S-boxes) are an important component of modern symmetric cryptography algorithms. They complicate symmetric transformations and introduce nonlinearity in the input-output relationship, which provides resistance to some cryptanalysis techniques. S-boxes generation can be done in a number of ways. However, the most promising are heuristic techniques. On the one hand, the generated S-boxes look like random settings, which complicates algebraic cryptanalysis. On the other hand, heuristic search makes it possible to achieve high nonlinearity and δ-uniformity, which complicates linear and differential cryptanalysis. In this article, we will explore the simplest local search algorithm for generating S-boxes. To assess the efficiency of the algorithm, the concept of a track of a cost function is introduced in the article. We optimize the algorithm parameters and show that with the chosen parameters it is possible to reliably form S-boxes with nonlinearity 104
WHS Cost Function for Generating S-boxes
No full textNonlinear substitution boxes (S-boxes) use in most modern symmetric cryptoalgorithms. They are designed to mix input data and take the essential part in ensuring resistance against known cryptoanalytic attacks (differential, linear, algebraic and other methods of cryptoanalysis). However, the random formation of nonlinear substitutions with the required rates is an extremely complex mathematical problem. We observe the heuristic techniques of S-boxes informed search, in particular, we consider the cost function used in most known algorithms (eg, local search, gradient lift, annealing simulation, genetic search, etc.). The purpose of our research is to determine the specific parameters of the heuristic function, which on the one hand do not reduce the degree of awareness of search nodes, and on the other hand do not require significant computational costs. We investigate the influence of individual parameters on the value of the cost function and on the complexity of its calculation. We also provide specific recommendations for the formation of parameters for the heuristic search of S-boxes
Tkachenko oscillations and the compressibility of a rotating Bose-Einstein condensate
No full textThe elastic oscillations of the vortex lattice of a cold Bose gas (Tkachenko modes) are shown to play a crucial role in the saturation of the compressibility sum rule, as a consequence of the hybridization with the longitudinal degrees of freedom. The presence of the vortex lattice is responsible for a q^2 behavior of the static structure factor at small wave vectors q, which implies the absence of long range order in 2D configurations at zero temperature. Sum rules are used to calculate the Tkachenko frequency in the presence of harmonic trapping. Results are derived in the Thomas-Fermi regime and compared with experiments as well as with previous theoretical estimates
The role of collective motion in examples of coarsening and self-assembly
No full textThe simplest prescription for building a patterned structure from its constituents is to add particles, one at a time, to an appropriate template. However, self-organizing molecular and colloidal systems in nature can evolve in much more hierarchical ways. Specifically, constituents (or clusters of constituents) may aggregate to form clusters (or clusters of clusters) that serve as building blocks for later stages of assembly. Here we evaluate the character and consequences of such collective motion in a set of prototypical assembly processes. We do so using computer simulations in which a system's capacity for hierarchical dynamics can be controlled systematically. By explicitly allowing or suppressing collective motion, we quantify its effects. We find that coarsening within a two dimensional attractive lattice gas (and an analogous off-lattice model in three dimensions) is naturally dominated by collective motion over a broad range of temperatures and densities. Under such circumstances, cluster mobility inhibits the development of uniform coexisting phases, especially when macroscopic segregation is strongly favored by thermodynamics. By contrast, the assembly of model viral capsids is not frustrated but is instead facilitated by collective moves, which promote the orderly binding of intermediates consisting of several monomers
Tkachenko modes and their damping in the vortex lattice regime of rapidly rotating bosons
No full textWe have found an exact analytical solution of the Bogoliubov-de Gennes equations for the Tkachenko modes of the vortex lattice in the lowest Landau level (LLL) in the thermodynamic limit (geometry of an infinite plane) at any momenta and calculated their damping rates. At finite temperatures both Beliaev and Landau damping leads to momentum-independent damping rates in the low-energy limit, which shows that, at sufficiently low energies, Tkachenko modes become strongly damped. We then found that the mean-square fluctuations of the density grow logarithmically at large distances, which indicates that the state is ordered in the vortex lattice only on a finite (although exponentially large) distance scale and introduces a low-momentum cutoff. Using this circumstance we showed that at finite temperatures the one-body density matrix undergoes an exponential decay at large distances
Higher education development in independent Ukraine (1991-2002)
No full textTkachenko Uliana. Higher education development in independent Ukraine (1991-2002). Journal of Education, Health and Sport. 2019;9(6):562-571. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.3661433
http://ojs.ukw.edu.pl/index.php/johs/article/view/7684
The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 1223 (26/01/2017).
1223 Journal of Education, Health and Sport eISSN 2391-8306 7
© The Authors 2019;
This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland
Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author (s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non commercial license Share alike.
(http://creativecommons.org/licenses/by-nc-sa/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited.
The authors declare that there is no conflict of interests regarding the publication of this paper.
Received: 10.06.2019. Revised: 24.06.2019. Accepted: 28.06.2019.
УДК: 378.091-043.86(477)"1991/2002"(09)
HIGHER EDUCATION DEVELOPMENT IN INDEPENDENT UKRAINE (1991-2002)
Uliana Tkachenko
Khmelnytskyi Humanitarian-Pedagogical Academy
[email protected]
Abstract
The article deals with the problem of higher education development in independent Ukraine in the period 1991-2002. The main ways of reforming the education system are outlined. The priorities of the state policy in the development of education are revealed. Areas of international cooperation in the field of education and science are of great importance.
Key words: education; development of higher education; reform; directions
A Useful Book for Journalists and Political Technologists About Global Monitoring of Election Procedures. Review: Tkachenko S. L. Monitoring Democracy Development: Witnessing Elections and Referendums. SPb.: Secretariat of the Board of Interparliamentary Assembly of CIS States. 2015. 200 p.
No full textA Useful Book for Journalists and Political Technologists
About Global Monitoring of Election Procedures. Review: Tkachenko S. L. Monitoring Democracy
Development: Witnessing Elections and Referendums. SPb.: Secretariat of the Board of Interparliamentary
Assembly of CIS States. 2015. 200 p
Mathematical model of process of loading of easy-deformable object on buffer layer
No full textNosov O. A. Mathematical model of process of loading of easy-deformable object on buffer layer / O. A. Nosov, E. S. Tkachenko, S. M. Tolstolutskiy // IOP Conf. Series: Materials Science and Engineering. - 2018. - Vol.327. - 022102.The paper deals with the process of loading an easily deformed object onto a gas buffer layer. Equations for finding the stiffness and damping coefficients are obtained. The described mathematical model allows designing the technological equipment for manufactures where gentle impact on object in the form of a disc is required
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
LC-Polymer composites for the realization of passive and active optoelectronic components
No full text- …
