An interactive program for finite incidence structures

1980 ◽  
Vol 14 (2) ◽  
pp. 174-181
Author(s):  
Marilena Barnabei ◽  
Giorgio Nicoletti
Keyword(s):  
Interactive Program ◽  
Incidence Structures ◽  
Finite Incidence

scholarly journals BRUCK NETS AND PARTIAL SHERK PLANES

2017 ◽  
Vol 104 (1) ◽  
pp. 1-12
Author(s):  
JOHN BAMBERG ◽  
JOANNA B. FAWCETT ◽  
JESSE LANSDOWN
Keyword(s):  
Affine Plane ◽  
Finite Geometries ◽  
Affine Planes ◽  
Incidence Structures ◽  
Finite Affine ◽  
Odd Order ◽  
Finite Incidence ◽  
Desarguesian Affine Plane

In Bachmann [Aufbau der Geometrie aus dem Spiegelungsbegriff, Die Grundlehren der mathematischen Wissenschaften, Bd. XCVI (Springer, Berlin–Göttingen–Heidelberg, 1959)], it was shown that a finite metric plane is a Desarguesian affine plane of odd order equipped with a perpendicularity relation on lines and that the converse is also true. Sherk [‘Finite incidence structures with orthogonality’, Canad. J. Math.19 (1967), 1078–1083] generalised this result to characterise the finite affine planes of odd order by removing the ‘three reflections axioms’ from a metric plane. We show that one can obtain a larger class of natural finite geometries, the so-called Bruck nets of even degree, by weakening Sherk’s axioms to allow noncollinear points.

Colouring finite incidence structures

1986 ◽  
Vol 2 (1) ◽  
pp. 339-346 ◽  
Author(s):  
J. Csima ◽  
Z. Füredi
Keyword(s):  
Incidence Structures ◽  
Finite Incidence

Finite Incidence Structures with Orthogonality

1967 ◽  
Vol 19 ◽  
pp. 1078-1083 ◽  
Author(s):  
F. A. Sherk
Keyword(s):  
Incidence Structure ◽  
Affine Planes ◽  
Axiom A ◽  
Incidence Structures ◽  
Finite Incidence

An incidence structure consists of two sets of elements, called points and blocks, together with a relation, called incidence, between elements of the two sets. Well-known examples are inversive planes, in which the blocks are circles, and projective and affine planes, in which the blocks are lines. Thus in various examples of incidence structures, the blocks may have various interpretations. Very shortly, however, we shall impose a condition (Axiom A) which ensures that the blocks behave like lines. In anticipation of this, we shall refer to the set of blocks as the set of lines. Also, we shall employ the usual terminology of incidence, such as “lies on,” “passes through,” “meet,” “join.” etc.

Tejo 1– An Interactive Program for the Division of Estuaries into Homogeneous Areas

1987 ◽  
Vol 19 (9) ◽  
pp. 43-51 ◽  
Author(s):  
A. S. Câmara ◽  
M. Cardoso da Silva ◽  
L. Ramos ◽  
J. Gomes Ferreira
Keyword(s):  
Water Quality ◽  
Computer Program ◽  
Heuristic Algorithm ◽  
Management Model ◽  
Interactive Program ◽  
Basin Management ◽  
Interactive Computer Program ◽  
Lake Basins

The division of an estuary into homogeneous areas from both hydrodynamic and ecological standpoints is essential to any estuarine basin management model. This paper presents an approach based on a heuristic algorithm to achieve such a division. The methodology implemented through an interactive computer program named Tejo 1 applies morphological, water quality and management criteria in order to achieve the disaggregation. The approach is equally applicable to river or lake basins, with only minor adaptations. An application of Tejo 1 to the Tejo estuary is included for illustrative purposes, which resulted in the final division of the estuary into 11 homogeneous areas.

An interactive program advising system

1976 ◽  
Vol 10 (SI) ◽  
pp. 335-341 ◽  
Author(s):  
Will Gillett
Keyword(s):  
Interactive Program
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