Boolean Packings in Dowling Geometries
نویسندگان
چکیده
منابع مشابه
Dowling group geometries and the critical problem
This paper relates the critical problem of Crapo and Rota [ " On the Foundations of Combinatorial Theory: Combinatorial Geometries, " M.I.T. Press, Cambridge, MA, 19703 to Dowling group geometries. If A is a finite group, Q,(A) is the rank-r Dowling group geometry over A, and M is a rank-r matroid embeddable as a minor of Q,(A), then it is shown that the critical exponent of M over A is well de...
متن کاملOn Dowling geometries of infinite groups
A finite subgeometry of a Dowling geometry for an infinite group is exhibited, which cannot be embedded in a Dowling geometry for any finite group; this provides a negative answer to a question of Bonin. The question addressed herein is motivated by the following fundamental result of Rado, concerning the embeddability of finite geometries in projective geometries [Ra, Theorem 4]: Theorem. Ever...
متن کاملTransient and asymptotic dispersion in confined sphere packings with cylindrical and non-cylindrical conduit geometries.
We study the time and length scales of hydrodynamic dispersion in confined monodisperse sphere packings as a function of the conduit geometry. By a modified Jodrey-Tory algorithm, we generated packings at a bed porosity (interstitial void fraction) of ε=0.40 in conduits with circular, rectangular, or semicircular cross section of area 100πd(p)(2) (where d(p) is the sphere diameter) and dimensio...
متن کاملThe Generalized Dowling Lattices
In this paper we study a new class of lattices called the generalized Dowling lattices. These lattices are parametrized by a positive integer n , a finite group G , and a meet sublattice K of the lattice of subgroups of G . For an appropriate choice of K the generalized Dowling lattice Dn{G,K) agrees with the ordinary Dowling lattice Dn(G). For a different choice of K, the generalized Dowling l...
متن کاملDowling-Degos disease.
Dowling-Degos disease (DDD) is a rare autosomal dominant inherited pigmentary disorder of the flexures with a reticulate aspect and with presence of prominent comedone-like lesions and pitted scars. The diagnosis includes acanthosis nigricans as well as other reticulate pigmentary disorders classified into: dyschromatrosis symmetrica hereditaria (DSH), dyschromatosis universalis hereditaria (DU...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: European Journal of Combinatorics
سال: 1998
ISSN: 0195-6698
DOI: 10.1006/eujc.1998.0230