The groups of projectivities in finite planes

2015 ◽  
pp. 271-277
Author(s):  
Theo Grundhöfer
Keyword(s):  
1996 ◽  
Vol 57 (1-2) ◽  
pp. 20-26 ◽  
Author(s):  
Rafael Artzy ◽  
Gy�rgy Kiss

1964 ◽  
Vol 15 (1) ◽  
pp. 378-384 ◽  
Author(s):  
T. G. Ostrom
Keyword(s):  

10.37236/5717 ◽  
2016 ◽  
Vol 23 (2) ◽  
Author(s):  
Jan De Beule ◽  
Tamás Héger ◽  
Tamás Szőnyi ◽  
Geertrui Van de Voorde

In this paper, by using properties of Baer subplanes, we describe the construction of a minimal blocking set in the Hall plane of order $q^2$ of size $q^2+2q+2$ admitting $1-$, $2-$, $3-$, $4-$, $(q+1)-$ and $(q+2)-$secants. As a corollary, we obtain the existence of a minimal blocking set of a non-Desarguesian affine plane of order $q^2$ of size at most $4q^2/3+5q/3$, which is considerably smaller than $2q^2-1$, the Jamison bound for the size of a minimal blocking set in an affine Desarguesian plane of order $q^2$.We also consider particular André planes of order $q$, where $q$ is a power of the prime $p$, and give a construction of a small minimal blocking set which admits a secant line not meeting the blocking set in $1$ mod $p$ points. Furthermore, we elaborate on the connection of this problem with the study of value sets of certain polynomials and with the construction of small double blocking sets in Desarguesian projective planes; in both topics we provide some new results.


2018 ◽  
Vol 160 ◽  
pp. 62-83 ◽  
Author(s):  
Gábor Korchmáros ◽  
Nicola Pace ◽  
Angelo Sonnino

1983 ◽  
Vol 44 (3) ◽  
pp. 319-320 ◽  
Author(s):  
Jerald A. Kabell
Keyword(s):  

2010 ◽  
Vol 02 (04) ◽  
pp. 871-887 ◽  
Author(s):  
GUOYANG FU ◽  
LEI HE ◽  
GUOWEI MA

This paper describes an algorithm to generate the realistic numerical representation of three-dimensional rock masses. The discontinuities can be treated as infinite or finite planes with or without thickness. A finite plane is represented by a polygon and defined using centroid of the polygon, orientation, geometry in 2D plane, the angle between strike line and reference line and other properties including cohesion, friction angle, tensile strength and aperture. Through 3D discontinuity network simulation, the information of discontinuities is obtained as the input data for block generation. The block generation process includes boundary planes cutting, discontinuities cutting and block integration. The results are also verified by graphical check, topological and geometrical properties of a polyhedron. The algorithm we adopt is convenient to be developed into a computer program. The generated model, in which the blocks and loops of blocks could be convex or concave, can be used for single block stability analysis or block model codes like discrete element method (DEM) and discontinuous deformation analysis (DDA).


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