7 research outputs found

    Metrical properties of the set of bent functions in view of duality

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    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

    The group of automorphisms of the set of self-dual bent functions

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    A bent function is a Boolean function in even number of variables which is on the maximal Hamming distance from the set of affine Boolean functions. It is called self-dual if it coincides with its dual. It is called anti-self-dual if it is equal to the negation of its dual. A mapping of the set of all Boolean functions in n variables to itself is said to be isometric if it preserves the Hamming distance. In this paper we study isometric mappings which preserve self-duality and anti-self-duality of a Boolean bent function. The complete characterization of these mappings is obtained for n>2. Based on this result, the set of isometric mappings which preserve the Rayleigh quotient of the Sylvester Hadamard matrix, is characterized. The Rayleigh quotient measures the Hamming distnace between bent function and its dual, so as a corollary, all isometric mappings which preserve bentness and the Hamming distance between bent function and its dual are described

    О мСтричСских свойствах мноТСства ΡΠ°ΠΌΠΎΠ΄ΡƒΠ°Π»ΡŒΠ½Ρ‹Ρ… Π±Π΅Π½Ρ‚-Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΉ

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    ΠŸΡ€ΠΈΠ²ΠΎΠ΄ΠΈΡ‚ΡΡ ΠΎΠ±Π·ΠΎΡ€ извСстных мСтричСских свойств мноТСства ΡΠ°ΠΌΠΎΠ΄ΡƒΠ°Π»ΡŒΠ½Ρ‹Ρ… Π±Π΅Π½Ρ‚- Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΉ. Π‘Π΅Π½Ρ‚-функция называСтся ΡΠ°ΠΌΠΎΠ΄ΡƒΠ°Π»ΡŒΠ½ΠΎΠΉ, Ссли ΠΎΠ½Π° совпадаСт со своСй Π΄ΡƒΠ°Π»ΡŒΠ½ΠΎΠΉ Π±Π΅Π½Ρ‚-Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠ΅ΠΉ, ΠΈ Π°Π½Ρ‚ΠΈ-ΡΠ°ΠΌΠΎΠ΄ΡƒΠ°Π»ΡŒΠ½ΠΎΠΉ, Ссли совпадаСт с ΠΎΡ‚Ρ€ΠΈΡ†Π°Π½ΠΈΠ΅ΠΌ своСй Π΄ΡƒΠ°Π»ΡŒΠ½ΠΎΠΉ. ΠŸΡ€ΠΈΠ²ΠΎΠ΄ΠΈΡ‚ΡΡ ΠΏΠΎΠ»Π½Ρ‹ΠΉ спСктр расстояний Π₯эмминга ΠΌΠ΅ΠΆΠ΄Ρƒ ΡΠ°ΠΌΠΎΠ΄ΡƒΠ°Π»ΡŒΠ½Ρ‹ΠΌΠΈ Π±Π΅Π½Ρ‚-функциями ΠΈΠ· класса ΠœΡΠΉΠΎΡ€Π°Π½Π° β€” ΠœΠ°ΠΊΠ€Π°Ρ€Π»Π°Π½Π΄Π°. Π”Π°ΡŽΡ‚ΡΡ Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹, ΠΊΠ°ΡΠ°ΡŽΡ‰ΠΈΠ΅ΡΡ Ρ…Π°Ρ€Π°ΠΊΡ‚Π΅Ρ€ΠΈΠ·Π°Ρ†ΠΈΠΈ Π±ΡƒΠ»Π΅Π²Ρ‹Ρ… Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΉ, находящихся Π½Π° максимально Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΠΌ ΡƒΠ΄Π°Π»Π΅Π½ΠΈΠΈ ΠΎΡ‚ мноТСства ΡΠ°ΠΌΠΎΠ΄ΡƒΠ°Π»ΡŒΠ½Ρ‹Ρ… Π±Π΅Π½Ρ‚-Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΉ. ΠžΠΏΠΈΡΠ°Π½Ρ‹ Π³Ρ€ΡƒΠΏΠΏΡ‹ Π°Π²Ρ‚ΠΎΠΌΠΎΡ€Ρ„ΠΈΠ·ΠΌΠΎΠ² мноТСств ΡΠ°ΠΌΠΎΠ΄ΡƒΠ°Π»ΡŒΠ½Ρ‹Ρ… ΠΈ Π°Π½Ρ‚ΠΈ-ΡΠ°ΠΌΠΎΠ΄ΡƒΠ°Π»ΡŒΠ½Ρ‹Ρ… Π±Π΅Π½Ρ‚-Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΉ ΠΎΡ‚ n ΠΏΠ΅Ρ€Π΅ΠΌΠ΅Π½Π½Ρ‹Ρ…, Π°Π²Ρ‚ΠΎΠΌΠΎΡ€Ρ„ΠΈΠ·ΠΌΡ‹ мноТСства Π±ΡƒΠ»Π΅Π²Ρ‹Ρ… Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΉ ΠΎΡ‚ n ΠΏΠ΅Ρ€Π΅ΠΌΠ΅Π½Π½Ρ‹Ρ…, ΠΊΠΎΡ‚ΠΎΡ€Ρ‹Π΅ ΠΌΠ΅Π½ΡΡŽΡ‚ мСстами мноТСства ΡΠ°ΠΌΠΎΠ΄ΡƒΠ°Π»ΡŒΠ½Ρ‹Ρ… ΠΈ Π°Π½Ρ‚ΠΈ-ΡΠ°ΠΌΠΎΠ΄ΡƒΠ°Π»ΡŒΠ½Ρ‹Ρ… Π±Π΅Π½Ρ‚- Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΉ, ΠΈΠ·ΠΎΠΌΠ΅Ρ‚Ρ€ΠΈΡ‡Π½Ρ‹Π΅ отобраТСния, ΡΠΎΡ…Ρ€Π°Π½ΡΡŽΡ‰ΠΈΠ΅ Π½Π΅ΠΈΠ·ΠΌΠ΅Π½Π½Ρ‹ΠΌ ΠΎΡ‚Π½ΠΎΡˆΠ΅Π½ΠΈΠ΅ РэлСя ΠΊΠ°ΠΆΠ΄ΠΎΠΉ Π±ΡƒΠ»Π΅Π²ΠΎΠΉ Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΈ ΠΎΡ‚ n ΠΏΠ΅Ρ€Π΅ΠΌΠ΅Π½Π½Ρ‹Ρ…. Даётся характСризация всСх ΠΈΠ·ΠΎ- ΠΌΠ΅Ρ‚Ρ€ΠΈΡ‡Π½Ρ‹Ρ… ΠΎΡ‚ΠΎΠ±Ρ€Π°ΠΆΠ΅Π½ΠΈΠΉ, ΡΠΎΡ…Ρ€Π°Π½ΡΡŽΡ‰ΠΈΡ… ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡŒΠ½ΡƒΡŽ Π½Π΅Π»ΠΈΠ½Π΅ΠΉΠ½ΠΎΡΡ‚ΡŒ ΠΈ расстояниС Π₯эмминга ΠΌΠ΅ΠΆΠ΄Ρƒ ΠΊΠ°ΠΆΠ΄ΠΎΠΉ Π±Π΅Π½Ρ‚-Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΉ ΠΈ Π΄ΡƒΠ°Π»ΡŒΠ½ΠΎΠΉ ΠΊ Π½Π΅ΠΉ

    Packing and covering in combinatorics

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    An extensive English language bibliography on graph theory and its applications

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    Bibliography on graph theory and its application

    Subject Index Volumes 1–200

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