250 research outputs found
Metrical properties of the set of bent functions in view of duality
In the paper, we give a review of metrical properties of the entire set of bent functions and its significant subclasses of self-dual and anti-self-dual bent functions. We present results for iterative construction of bent functions in n + 2 variables based on the concatenation of four bent functions and consider related open problem proposed by one of the authors. Criterion of self-duality of such functions is discussed. It is explored that the pair of sets of bent functions and affine functions as well as a pair of sets of self-dual and anti-self-dual bent functions in n > 4 variables is a pair of mutually maximally distant sets that implies metrical duality. Groups of automorphisms of the sets of bent functions and (anti-)self-dual bent functions are discussed. The solution to the problem of preserving bentness and the Hamming distance between bent function and its dual within automorphisms of the set of all Boolean functions in n variables is considered
Relativistic Model of Detonation Transition from Neutron to Strange Matter
We study the conversion of neutron matter into strange matter as a detonation
wave. The detonation is assumed to originate from a central region in a
spherically symmetric background of neutrons with a varying radial density
distribution. We present self-similar solutions for the propagation of
detonation in static and collapsing backgrounds of neutron matter. The
solutions are obtained in the framework of general relativistic hydrodynamics,
and are relevant for the possible transition of neutron into strange stars.
Conditions for the formation of either bare or crusted strange stars are
discussed.Comment: 16 pages, 4 figures. Submitted to IJMP
Mathematical methods in solutions of the problems from the Third International Students' Olympiad in Cryptography
The mathematical problems and their solutions of the Third International
Students' Olympiad in Cryptography NSUCRYPTO'2016 are presented. We consider
mathematical problems related to the construction of algebraic immune vectorial
Boolean functions and big Fermat numbers, problems about secrete sharing
schemes and pseudorandom binary sequences, biometric cryptosystems and the
blockchain technology, etc. Two open problems in mathematical cryptography are
also discussed and a solution for one of them proposed by a participant during
the Olympiad is described. It was the first time in the Olympiad history
Fitness in the education system
The authors consider the questions of the deliberate introduction fitness technologies in the system of physical education, physical culture for the development and education of children and teenagers, the youth, the recovery of the populationΠΠ²ΡΠΎΡΡ ΡΠ°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°ΡΡ Π²ΠΎΠΏΡΠΎΡΡ ΡΠ΅Π»Π΅Π½Π°ΠΏΡΠ°Π²Π»Π΅Π½Π½ΠΎΠ³ΠΎ Π²Π½Π΅Π΄ΡΠ΅Π½ΠΈΡ ΡΠΈΡΠ½Π΅Ρ-ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΠΉ Π² ΡΠΈΡΡΠ΅ΠΌΡ ΡΠΈΠ·ΠΊΡΠ»ΡΡΡΡΠ½ΠΎΠ³ΠΎ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ, Π² Π·Π°Π½ΡΡΠΈΡ ΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΊΡΠ»ΡΡΡΡΠΎΠΉ Π΄Π»Ρ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΠΈ Π²ΠΎΡΠΏΠΈΡΠ°Π½ΠΈΡ Π΄Π΅ΡΠ΅ΠΉ ΠΈ ΠΏΠΎΠ΄ΡΠΎΡΡΠΊΠΎΠ², ΡΡΠ°ΡΠ΅ΠΉΡΡ ΠΌΠΎΠ»ΠΎΠ΄Π΅ΠΆΠΈ, ΠΎΠ·Π΄ΠΎΡΠΎΠ²Π»Π΅Π½ΠΈΡ Π½Π°ΡΠ΅Π»Π΅Π½ΠΈ
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