The goal of the present paper is to provide a gallery of small directed strongly regular graphs.For each graph of order n≤12 and valency k<n/2,a diagram is depicted,its relation to other small directed strongly re...The goal of the present paper is to provide a gallery of small directed strongly regular graphs.For each graph of order n≤12 and valency k<n/2,a diagram is depicted,its relation to other small directed strongly regular graphs is revealed,the full group of automorphisms is described,and some other nice properties are given.To each graph a list of interesting subgraphs is provided as well.展开更多
Using Galois rings and Galois fields, we construct several infinite classes of partial geometric difference sets, and partial geometric difference families, with new parameters. Furthermore, these partial geometric di...Using Galois rings and Galois fields, we construct several infinite classes of partial geometric difference sets, and partial geometric difference families, with new parameters. Furthermore, these partial geometric difference sets(and partial geometric difference families) correspond to new infinite families of directed strongly regular graphs. We also discuss some of the links between partially balanced designs, 2-adesigns(which were recently coined by Cunsheng Ding in "Codes from Difference Sets"(2015)), and partial geometric designs, and make an investigation into when a 2-adesign is a partial geometric design.展开更多
文摘The goal of the present paper is to provide a gallery of small directed strongly regular graphs.For each graph of order n≤12 and valency k<n/2,a diagram is depicted,its relation to other small directed strongly regular graphs is revealed,the full group of automorphisms is described,and some other nice properties are given.To each graph a list of interesting subgraphs is provided as well.
文摘Using Galois rings and Galois fields, we construct several infinite classes of partial geometric difference sets, and partial geometric difference families, with new parameters. Furthermore, these partial geometric difference sets(and partial geometric difference families) correspond to new infinite families of directed strongly regular graphs. We also discuss some of the links between partially balanced designs, 2-adesigns(which were recently coined by Cunsheng Ding in "Codes from Difference Sets"(2015)), and partial geometric designs, and make an investigation into when a 2-adesign is a partial geometric design.
