oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Rank deficiency in sparse random GF[2] matrices  [PDF]
R. W. R. Darling,Mathew D. Penrose,Andrew R. Wade,Sandy L. Zabell
Mathematics , 2012, DOI: 10.1214/EJP.v19-2458
Abstract: Let $M$ be a random $m \times n$ matrix with binary entries and i.i.d. rows. The weight (i.e., number of ones) of a row has a specified probability distribution, with the row chosen uniformly at random given its weight. Let $N(n,m)$ denote the number of left null vectors in ${0,1}^m$ for $M$ (including the zero vector), where addition is mod 2. We take $n, m \to \infty$, with $m/n \to \alpha > 0$, while the weight distribution may vary with $n$ but converges weakly to a limiting distribution on ${3, 4, 5, ...}$; let $W$ denote a variable with this limiting distribution. Identifying $M$ with a hypergraph on $n$ vertices, we define the 2-core of $M$ as the terminal state of an iterative algorithm that deletes every row incident to a column of degree 1. We identify two thresholds $\alpha^*$ and $\underline{\alpha}$, and describe them analytically in terms of the distribution of $W$. Threshold $\alpha^*$ marks the infimum of values of $\alpha$ at which $n^{-1} \log{\mathbb{E} [N(n,m)}]$ converges to a positive limit, while $\underline{\alpha}$ marks the infimum of values of $\alpha$ at which there is a 2-core of non-negligible size compared to $n$ having more rows than non-empty columns. We have $1/2 \leq \alpha^* \leq \underline{\alpha} \leq 1$, and typically these inequalities are strict; for example when $W = 3$ almost surely, numerics give $\alpha^* = 0.88949 ...$ and $\underline{\alpha} = 0.91793 ...$ (previous work on this model has mainly been concerned with such cases where $W$ is non-random). The threshold of values of $\alpha$ for which $N(n,m) \geq 2$ in probability lies in $[\alpha^*,\underline{\alpha}]$ and is conjectured to equal $\underline{\alpha}$. The random row weight setting gives rise to interesting new phenomena not present in the non-random case that has been the focus of previous work.
On the number of Steiner triple systems S(2^m-1,3,2) of rank 2^m - m + 2 over GF(2)  [PDF]
Dmitrii Zinoviev
Mathematics , 2015,
Abstract: We obtain the number of different Steiner triple systems S(2^m-1,3,2) of rank 2^m-m+2 over the field GF(2).
AN IDENTIFICATION SCHEME BASED ON PARITY CHECK MATRIX OF RANK DISTANCE CODES OVER GF(qN)
基于GF(qN)上秩距离码的校验矩阵的验证方案

Du Weizhang,Wang Xinmei,
杜伟章
,王新梅

电子与信息学报 , 2001,
Abstract: An identification scheme based on parity check matrix of error-correcting codes over GF(2) was proposed in the paper "A New Paradigm for Public Key Identification" by J. Stern(1996), a new identification scheme based on parity check matrix of rank distance codes over GF(qN) (q is a prime) is proposed in this paper, the limitation on the weight of mysterious datum s is changed into the limitation on the rank of s. It is proved that the given protocol is a zero-knowledge interactive proof in the random oracle model, and it is shown that the scheme is more secure than the scheme of J. Stern when parameters are selected properly.
Typical rank of coin-toss power-law random matrices over GF(2)  [PDF]
Salvatore Mandrà,Marco Cosentino Lagomarsino,Bruno Bassetti
Physics , 2010,
Abstract: Random linear systems over the Galois Field modulo 2 have an interest in connection with problems ranging from computational optimization to complex networks. They are often approached using random matrices with Poisson-distributed or finite column/row-sums. This technical note considers the typical rank of random matrices belonging to a specific ensemble wich has genuinely power-law distributed column-sums. For this ensemble, we find a formula for calculating the typical rank in the limit of large matrices as a function of the power-law exponent and the shape of the matrix, and characterize its behavior through "phase diagrams" with varying model parameters.
Fourier Sparsity of GF(2) Polynomials  [PDF]
Hing Yin Tsang,Ning Xie,Shengyu Zhang
Computer Science , 2015,
Abstract: We study a conjecture called "linear rank conjecture" recently raised in (Tsang et al., FOCS'13), which asserts that if many linear constraints are required to lower the degree of a GF(2) polynomial, then the Fourier sparsity (i.e. number of non-zero Fourier coefficients) of the polynomial must be large. We notice that the conjecture implies a surprising phenomenon that if the highest degree monomials of a GF(2) polynomial satisfy a certain condition, then the Fourier sparsity of the polynomial is large regardless of the monomials of lower degrees -- whose number is generally much larger than that of the highest degree monomials. We develop a new technique for proving lower bound on the Fourier sparsity of GF(2) polynomials, and apply it to certain special classes of polynomials to showcase the above phenomenon.
Efficiently Testing Sparse GF(2) Polynomials  [PDF]
Ilias Diakonikolas,Homin K. Lee,Kevin Matulef,Rocco A. Servedio,Andrew Wan
Computer Science , 2008,
Abstract: We give the first algorithm that is both query-efficient and time-efficient for testing whether an unknown function $f: \{0,1\}^n \to \{0,1\}$ is an $s$-sparse GF(2) polynomial versus $\eps$-far from every such polynomial. Our algorithm makes $\poly(s,1/\eps)$ black-box queries to $f$ and runs in time $n \cdot \poly(s,1/\eps)$. The only previous algorithm for this testing problem \cite{DLM+:07} used poly$(s,1/\eps)$ queries, but had running time exponential in $s$ and super-polynomial in $1/\eps$. Our approach significantly extends the ``testing by implicit learning'' methodology of \cite{DLM+:07}. The learning component of that earlier work was a brute-force exhaustive search over a concept class to find a hypothesis consistent with a sample of random examples. In this work, the learning component is a sophisticated exact learning algorithm for sparse GF(2) polynomials due to Schapire and Sellie \cite{SchapireSellie:96}. A crucial element of this work, which enables us to simulate the membership queries required by \cite{SchapireSellie:96}, is an analysis establishing new properties of how sparse GF(2) polynomials simplify under certain restrictions of ``low-influence'' sets of variables.
Constant-Rank Codes  [PDF]
Maximilien Gadouleau,Zhiyuan Yan
Mathematics , 2008,
Abstract: Constant-dimension codes have recently received attention due to their significance to error control in noncoherent random network coding. In this paper, we show that constant-rank codes are closely related to constant-dimension codes and we study the properties of constant-rank codes. We first introduce a relation between vectors in $\mathrm{GF}(q^m)^n$ and subspaces of $\mathrm{GF}(q)^m$ or $\mathrm{GF}(q)^n$, and use it to establish a relation between constant-rank codes and constant-dimension codes. We then derive bounds on the maximum cardinality of constant-rank codes with given rank weight and minimum rank distance. Finally, we investigate the asymptotic behavior of the maximal cardinality of constant-rank codes with given rank weight and minimum rank distance.
The number of rank-$k$ flats in a matroid with no $U_{2,n}$-minor  [PDF]
Peter Nelson
Mathematics , 2013,
Abstract: We show that, if $k$ and $\ell$ are positive integers and $r$ is sufficiently large, then the number of rank-$k$ flats in a rank-$r$ matroid $M$ with no $U_{2,\ell+2}$-minor is less than or equal to number of rank-$k$ flats in a rank-$r$ projective geometry over GF$(q)$, where $q$ is the largest prime power not exceeding $\ell$.
Five Constructions of Permutation Polynomials over $\gf(q^2)$  [PDF]
Cunsheng Ding,Pingzhi Yuan
Mathematics , 2015,
Abstract: Four recursive constructions of permutation polynomials over $\gf(q^2)$ with those over $\gf(q)$ are developed and applied to a few famous classes of permutation polynomials. They produce infinitely many new permutation polynomials over $\gf(q^{2^\ell})$ for any positive integer $\ell$ with any given permutation polynomial over $\gf(q)$. A generic construction of permutation polynomials over $\gf(2^{2m})$ with o-polynomials over $\gf(2^m)$ is also presented, and a number of new classes of permutation polynomials over $\gf(2^{2m})$ are obtained.
On the Fine Structure of the Projective Line Over GF(2) x GF(2) x GF(2)  [PDF]
Metod Saniga,Michel Planat
Mathematics , 2006, DOI: 10.1016/j.chaos.2006.09.056
Abstract: The paper gives a succinct appraisal of the properties of the projective line defined over the direct product ring $R\_{\triangle} \equiv$ GF(2)$\otimesGF(2)\otimes$GF(2). The ring is remarkable in that except for unity, all the remaining seven elements are zero-divisors, the non-trivial ones forming two distinct sets of three; elementary ('slim') and composite ('fat'). Due to this fact, the line in question is endowed with a very intricate structure. It contains twenty-seven points, every point has eighteen neighbour points, the neighbourhoods of two distant points share twelve points and those of three pairwise distant points have six points in common -- namely those with coordinates having both the entries `fat' zero-divisors. Algebraically, the points of the line can be partitioned into three groups: a) the group comprising three distinguished points of the ordinary projective line of order two (the 'nucleus'), b) the group composed of twelve points whose coordinates feature both the unit(y) and a zero-divisor (the 'inner shell') and c) the group of twelve points whose coordinates have both the entries zero-divisors (the 'outer shell'). The points of the last two groups can further be split into two subgroups of six points each; while in the former case there is a perfect symmetry between the two subsets, in the latter case the subgroups have a different footing, reflecting the existence of the two kinds of a zero-divisor. The structure of the two shells, the way how they are interconnected and their link with the nucleus are all fully revealed and illustrated in terms of the neighbour/distant relation. Possible applications of this finite ring geometry are also mentioned.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.