Combinatorics 86

Content: 
General Editor
Page ii

Edited by
Page iii

Copyright page
Page iv

Foreword
Page v
A. Barlotti, M. Marchi, G. Tallini

Opening Welcome
Page vii
Giuseppe Tallini

Participants
Pages xiii-xvi

Net of Rationality in a Minkowski Plane Original Research Article
Pages 1-6
Rafael Artzy

A New Class of Translation Planes Original Research Article
Pages 7-20
R.D. Baker, G.L. Ebert

Quasigroups and Groups Arising from Cubic Surfaces Original Research Article
Pages 21-30
Lucien Beneteau

Blocking Sets in the Large Mathieu Designs, I : the Case S(3, 6, 22) Original Research Article
Pages 31-42
Luigia Berardi

Blocking Sets in the Projective Plane of Order Four Original Research Article
Pages 43-50
Luigia Berardi, Franco Eugeni

Kalahari and the Sequence “Sloane No. 377” Original Research Article
Pages 51-58
Dieter Betten

Enciphered Geometry. Some Applications of Geometry To Cryptography Original Research Article
Pages 59-68
Albrecht Beutelspacher

On Finite Grassmann Spaces Original Research Article
Pages 69-73
Paola Biondi

The Regular Subgroups of the Sharply 3–Transitive Finite Permutation Groups () Original Research Article
Pages 75-86
Arrigo Bonisoli

Hyperovals in Desarguesian Planes of Even Order Original Research Article
Pages 87-94
William Cherowitzo

Circular Block Designs from Planar Near-Rings Original Research Article
Pages 95-105
James R. Clay

Extending the Concept of Decomposability for Triple Systems Original Research Article
Pages 107-116
C.J. Colbourn, E. Mendelsohn, A. Rosa

Translation Partial Geometries Original Research Article
Pages 117-135
F. De Clerck, H. Gevaert, J.A. Thas

On Admissible Sets with Two Intersection Numbers in A Projective Plane Original Research Article
Pages 137-146
Marialuisa J. de Resmini

Commutative Finite A-Hypergroups of Length Two Original Research Article
Pages 147-156
Mario De Salvo

On Sets of Fixed Parity in Steiner Systems Original Research Article
Pages 157-167
Franco Eugeni, Stefano Innamorati

Blocking Sets of Index Two Original Research Article
Pages 169-176
Franco Eugeni, Erika Mayer

A Short Proof that Ordered Linear Spaces are Locally Projective Original Research Article
Pages 177-179
Rolfdieter Frank

Midpoints and Midlines in a Finite Hyperbolic Plane Original Research Article
Pages 181-187
Cyril W.L. Garner

Hall-Ryser Type Theorems for Relative Difference Sets Original Research Article
Pages 189-193
Dina Ghinelli Smit

Coordinatization of Generalized Quadrangles Original Research Article
Pages 195-207
G. Hanssens, H. Van Maldeghem

Construction of Some Planar Translation Spaces Original Research Article
Pages 209-216
H. Lenz, Armin Herzer

Regular Sets in Geometries Original Research Article
Pages 217-223
J.D. Key

Group Preserving Extensions of Skew Parabola Planes Original Research Article
Pages 225-229
Norbert Knarr

Products of Involutions in Orthogonal Groups Original Research Article
Pages 231-247
Frieder Knüppel

Examples of Ovoidal Möbius Planes of Hering Class III Original Research Article
Pages 249-250
Hans-Joachim Kroll

A Construction of Pairs and Triples of k-Incomplete Orthogonal Arrays Original Research Article
Pages 251-255
C. Pellegrino, P. Lancellotti

Relative Infinity in Projective De Sitter Spacetime and Its Relation to Proper Time Original Research Article
Pages 257-264
J.A. Lester

Affine Hjelmslev Rings and Planes Original Research Article
Pages 265-275
J.W. (Michael) Lorimer

Irreducible Representations of Hecke Algebras of Rank 2 Geometries Original Research Article
Pages 277-279
Stefan Löwe

A Characterization of Pappian Affine Hjelmslev Planes Original Research Article
Pages 281-291
Helmut Mäurer, Wolfgang Nolte

Embedding Locally Projective Planar Spaces Into Projective Spaces Original Research Article
Pages 293-295
Klaus Metsch

On Topological Incidence Groupoids Original Research Article
Pages 297-300
Rita Meyer, Jürgen Misfeld, Elena Zizioli

Isomorphisms of Finite Hypergroupoids Original Research Article
Pages 301-310
Renato Migliorato

Seminversive Planes Original Research Article
Pages 311-313
Domenico Olanda

Geometric and Algebraic Methods in the Classification of Geometries Belonging to Lie Diagrams Original Research Article
Pages 315-355
Antonio Pasini

The Thas-Fisher Generalized Quadrangles Original Research Article
Pages 357-366
Stanley E. Payne

On Group Spaces Defined by Semidirect Products of Groups Original Research Article
Pages 367-374
J. Pfalzgraf

On Permutation Properties for Finitely Generated Semigroups Original Research Article
Pages 375-376
Giuseppe Pirillo

On k-Sets of Type (o,m,n) in Sr,q with Three Exterior Hyperplanes Original Research Article
Pages 377-383
Rita Procesi Ciampi, Rosaria Rota

An Algorithm for LS - Colourations Original Research Article
Pages 385-390
Luigia Puccio

A Blocking Set in PG(3,q), q ≥ 5 Original Research Article
Pages 391-394
Sandro Rajola

A Characterization of All Abelian Groups Whose Lattice of Precompact Group Topologies Represents A Projective Geometry Original Research Article
Pages 395-398
Dieter Remus

Groups of Homologies in 4-Dimensional Stable Planes Are Classical Original Research Article
Pages 399-403
Hans-Peter Seidel

Polynomial Species and Connections Among Bases of the Symmetric Polynomials Original Research Article
Pages 405-412
Domenico Senato, Antonietta M. Venezia

Set and Sequence Closure for Finite Permutation Groups Original Research Article
Pages 413-419
Johannes Siemons

P-Cyclic Hypergroups with Three Characteristic Elements Original Research Article
Pages 421-426
Thomas N. Vougiouklis, Stefanos H. Spartalis

Order and Uniform Structure in Projective Geometry Original Research Article
Pages 427-431
Horst Szambien

On Blocking Sets in Finite Projective and Affine Spaces Original Research Article
Pages 433-450
Giuseppe Tallini

Symmetric Designs without Ovals and Extremal Self-Dual Codes Original Research Article
Pages 451-457
Vladimir D. Tonchev

Groups in Hypergroups Original Research Article
Pages 459-467
Thomas Vougiouklis

The Perron-Frobenius Projection in the Theory of Graphs, Digraphs, Designs and Stochastic Processes Original Research Article
Pages 469-477
Karl Erich Wolff

On the Non-Existence of Certain Difference Sets Original Research Article
Pages 479-484
N. Zagaglia Salvi

On Complete 12-Arcs in Projective Planes of Order 12 Original Research Article
Pages 485-492
Corrado Zanella

Block Designs Admitting Flag Transitive Groups of Automorphisms Original Research Article
Pages 493-495
Paul-Hermann Zieschang

An Independence Theorem on the Conditions for Incidence Loops Original Research Article
Pages 497-502
Elena Zizioli