3 citations · 5 across the 11 of their papers we have counts for
13 papers
Balanced weightings and permutation matchings applied to the monoid of order-preserving mappings
Peter M. Higgins
We give a necessary and sufficient condition for a combinatorial D-class of a finite semigroup to have a permutation matching: that its structure matrix admit a balanced weighting,…
Production optimization by agents of differing work rates
Peter M. Higgins
We devise a scheme for producing, in the least possible time, identical objects with agents that work at differing speeds. This involves halting the process in order to tra…
Finite regular semigroups with permutations that map elements to inverses
Peter M. Higgins
We give an account on what is known on the subject of permutation matchings, which are bijections of a finite regular semigroup that map each element to one of its inverses. This i…
Orientation-preserving and orientation-reversing mappings: a new description
Peter M. Higgins, Alexei Vernitski
We characterise the respective semigroups of mappings that preserve, or that preserve or reverse orientation of a finite cycle, in terms of their actions on oriented triples and or…
A new formulation of the semigroup of orientation-preserving and orientation-reversing mappings
Peter M. Higgins, Alexei Vernitski
We characterize the respective semigroups of mappings that preserve, or that preserve or reverse orientation of a finite cycle, in terms of their actions on oriented triples and or…
Epimorphisms, dominions and H-commutative semigroups
Peter M. Higgins, Noor Alam, Noor Mohammad Khan
In the present paper, a series of results and examples that explore the structural features of H-commutative semigroups are provided. We also generalise a result of Isbell from com…