David Bevan is an English mathematician, computer scientist and software developer. He is known for Bevan's theorem, which gives the asymptotic enumeration of grid classes of permutations and for his work on enumerating the class of permutations avoiding the pattern 1324. He is also known for devising weighted reference counting, an approach to computer

memory management Memory management is a form of resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when ...

that is suitable for use in

distributed systems A distributed system is a system whose components are located on different networked computers, which communicate and coordinate their actions by passing messages to one another from any system. Distributed computing is a field of computer sci ...

Work and research

Bevan is a lecturer in

combinatorics Combinatorics is an area of mathematics primarily concerned with counting, both as a means and an end in obtaining results, and certain properties of finite structures. It is closely related to many other areas of mathematics and has many appl ...

in the department of

Mathematics and Statistics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

at the

University of Strathclyde The University of Strathclyde ( gd, Oilthigh Shrath Chluaidh) is a public research university located in Glasgow, Scotland. Founded in 1796 as the Andersonian Institute, it is Glasgow's second-oldest university, having received its royal chart ...

. He has degrees in mathematics and computer science from the

University of Oxford , mottoeng = The Lord is my light , established = , endowment = £6.1 billion (including colleges) (2019) , budget = £2.145 billion (2019–20) , chancellor ...

and a degree in theology from the

London School of Theology The London School of Theology (LST), formerly London Bible College, is a British interdenominational evangelical theological college based in Northwood within the London Borough of Hillingdon. History During the 1930s A. J. Vereker, secreta ...

. He received his PhD in mathematics from

The Open University The Open University (OU) is a British public research university and the largest university in the United Kingdom by number of students. The majority of the OU's undergraduate students are based in the United Kingdom and principally study off- ...

in 2015; his thesis, ''On the growth of permutation classes'', was supervised by Robert Brignall. In 1987, as a research scientist at GEC's

Hirst Research Centre The Hirst Research Centre, also known as the GEC Hirst Research Centre or GEC Research Laboratories, was established in 1919 at Wembley, Middlesex, by the General Electric Company. History Formally opened in 1923, the site at East Lane, Wembley ...

in Wembley, he developed an approach to computer

, called weighted reference counting, that is suitable for use in

. During the 1990s, while working for the

Summer Institute of Linguistics SIL International (formerly known as the Summer Institute of Linguistics) is an evangelical Christian non-profit organization whose main purpose is to study, develop and document languages, especially those that are lesser-known, in order to ex ...

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

, he developed a computer program, called ''FindPhone'', that was widely used by field linguists to analyse phonetic data in order to understand the

phonology Phonology is the branch of linguistics that studies how languages or dialects systematically organize their sounds or, for sign languages, their constituent parts of signs. The term can also refer specifically to the sound or sign system of a ...

minority languages A minority language is a language spoken by a minority of the population of a territory. Such people are termed linguistic minorities or language minorities. With a total number of 196 sovereign states recognized internationally (as of 2019) and ...

. While employed by

Pitney Bowes Pitney Bowes Inc. is an American technology company most known for its postage meters and other mailing equipment and services, and with expansions into e-commerce, software, and other technologies. The company was founded by Arthur Pitney, who i ...

, he was a major contributor to the development of the FreeType text rendering library. Bevan's mathematical research has concerned areas of

enumerative combinatorics Enumerative combinatorics is an area of combinatorics that deals with the number of ways that certain patterns can be formed. Two examples of this type of problem are counting combinations and counting permutations. More generally, given an infin ...

, particularly in relation to permutation classes. He established that the growth rate of a monotone grid class of permutations is equal to the square of the

spectral radius In mathematics, the spectral radius of a square matrix is the maximum of the absolute values of its eigenvalues. More generally, the spectral radius of a bounded linear operator is the supremum of the absolute values of the elements of its spectru ...

of a related

bipartite graph In the mathematical field of graph theory, a bipartite graph (or bigraph) is a graph whose vertices can be divided into two disjoint and independent sets U and V, that is every edge connects a vertex in U to one in V. Vertex sets U and V are ...

. He has also determined bounds on the growth rate of the class of permutations avoiding the pattern 1324. In the Acknowledgements sections of his journal articles, he often includes the Latin phrase Soli Deo gloria.

Selected publications

* * * *

References

External links

David Bevan's page at the University of Strathclyde
{{DEFAULTSORT:Bevan, David Combinatorialists 21st-century English mathematicians English mathematicians English computer scientists Academics of the University of Strathclyde Alumni of The Queen's College, Oxford Alumni of the London School of Theology Alumni of the Open University 1961 births Living people