Results 271 to 280 of about 5,218,588 (299)

A Generalization of Difference Sets

Canadian Journal of Mathematics, 1967
A(v, k,λ)difference set Dis a set ofkdistinct residues{a1, a2,… ,ak} modulovsuch that every residueb ≢0 (modv)can be expressed in exactly λ ways in the formb≡ai— aj(modv).With each difference set we may associate a binary periodic sequence (s1, s2, …) withsi= 1 ifi(mod v) is inD,andsi= 0 otherwise.
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Difference sets and inverting the difference operator

Combinatorica, 1996
For \(A\subseteq N_0\) let \(D(A)\) be the set of differences of elements of \(A\) in \(N_0\). Problem: study equations \(D^k(X)=B\). There is a solution if \(0\in B\) and for each \(n\) there exists \(x\geq n\) such that each of the \(2^{k-1}\) intervals \([x-n, x+n]\), \([2x-n, 2x+n],\dots,[2^{k-1}x-n, 2^{k-1}x+n]\) is contained in \(B\).
Zoltán Füredi, Carl G. Jockusch Jr., Lee A. Rubel   +2 more
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Menon difference sets and relative difference sets

1991
Abstract The only known cyclic Menon difference set is the trivial difference set in Z4 corresponding to the Barker sequence 111-1. It has been conjectured that no other cyclic Menon difference set exists.
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Difference Sets: An Introduction

1999
We give an introductury treatment of the theory of difference sets focusing on the abelian case. This is meant to facilitate understanding of some other articles in this volume which will provide a detailed treatment of some important recent developments.
Jungnickel, Dieter, Pott, Alexander
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Concerning Difference Sets

Canadian Journal of Mathematics, 1953
A set of integers {a0, a1, … , an} is said to be a difference set modulo N if the set of differences {ai — aj (i,j = 0, 1, … , n) contains each non-zero residue mod N exactly once.
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On Finite Difference Sets

Acta Mathematica Hungarica, 1998
Let \(A\) denote a finite subset of \({\mathbb{R}}^n\). The difference set of \(A\) is given by \(A-A=\{a-b: a,b\in A\}\). The affine dimension of \(A\), denoted by \(d=\dim A\), is defined as the dimension of the smallest affine subspace containing \(A\). \textit{G. A. Freiman}, \textit{A. Heppes}, and \textit{B. Uhrin} derived the general lower bound
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Differences of Computably Enumerable Sets

MLQ, 2000
Summary: We consider the lower semilattice \({\mathcal D}\) of differences of c.e. sets under inclusion. It is shown that \({\mathcal D}\) is not distributive as a semilattice, and that the c.e. sets form a definable subclass.
Steffen Lempp, André Nies
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Quadrics and difference sets

Ars Comb., 1996
Let \(L\) be a linear form on the Galois field \(GF(q^{n + 1})\) over \(GF(q)\) \((n \geq 2)\). The authors characterize those integers \(s\) coprime to \(v = (q^{n + 1} - 1)/(q - 1)\) such that \(L(x^s)\) is (or is related to) a quadratic form on \(GF(q^{n + 1})\) over \(GF(q)\). This relates to a conjecture of Games (see \textit{R. A.
Wen-Ai Jackson, Kathleen A. S. Quinn, Peter R. Wild   +2 more
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On abelian difference set codes

Designs, Codes and Cryptography, 1992
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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Difference Sets and Recursion Theory

Mathematical Logic Quarterly, 1998
AbstractThere is a recursive set of natural numbers which is the difference set of some recursively enumerable set but which is not the difference set of any recursive set.
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