Ronald Martin Foster (3 October 1896 – 2 February 1998), was a

Bell Labs Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by mult ...

mathematician whose work was of significance regarding

electronic filter Electronic filters are a type of signal processing filter in the form of electrical circuits. This article covers those filters consisting of lumped electronic components, as opposed to distributed-element filters. That is, using component ...

s for use on telephone lines. He published an important paper, ''A Reactance Theorem'', (see

Foster's reactance theorem Foster's reactance theorem is an important theorem in the fields of electrical network analysis and synthesis. The theorem states that the reactance of a passive, lossless two-terminal (one-port) network always strictly monotonically increases ...

) which quickly inspired

Wilhelm Cauer Wilhelm Cauer (24 June 1900 – 22 April 1945) was a German mathematician and scientist. He is most noted for his work on the analysis and synthesis of electrical filters and his work marked the beginning of the field of network synthesis. Prior ...

to begin his program of

network synthesis filters Network, networking and networked may refer to: Science and technology * Network theory, the study of graphs as a representation of relations between discrete objects * Network science, an academic field that studies complex networks Mathematics ...

which put the design of filters on a firm mathematical footing. He is also known for the

Foster census In the mathematical field of graph theory, a graph is symmetric (or arc-transitive) if, given any two pairs of adjacent vertices and of , there is an automorphism :f : V(G) \rightarrow V(G) such that :f(u_1) = u_2 and f(v_1) = v_2. In ot ...

cubic Cubic may refer to: Science and mathematics * Cube (algebra), "cubic" measurement * Cube, a three-dimensional solid object bounded by six square faces, facets or sides, with three meeting at each vertex ** Cubic crystal system, a crystal system ...

symmetric graph In the mathematical field of graph theory, a graph is symmetric (or arc-transitive) if, given any two pairs of adjacent vertices and of , there is an automorphism :f : V(G) \rightarrow V(G) such that :f(u_1) = u_2 and f(v_1) = v_2. In ot ...

s and the 90-vertex cubic symmetric

Foster graph In the mathematical field of graph theory, the Foster graph is a bipartite 3-regular graph with 90 vertices and 135 edges. The Foster graph is Hamiltonian and has chromatic number 2, chromatic index 3, radius 8, diameter 8 and girth 10. It is ...

Education

Foster was a

Harvard College Harvard College is the undergraduate college of Harvard University, an Ivy League research university in Cambridge, Massachusetts. Founded in 1636, Harvard College is the original school of Harvard University, the oldest institution of higher ...

graduate S.B. (Mathematics), summa cum laude, Class of 1917. He also received two honorary Sc.D.s."The Foster Census: R.M. Foster's Census of Connected Symmetric Trivalent Graphs", by Ronald M. Foster, I.Z. Bouwer, W.W. Chernoff, B. Monson and Z. Star (1988) .

Professional career

*1917 – 1943 Research & Development Department (later

American Telephone & Telegraph AT&T Corporation, originally the American Telephone and Telegraph Company, is the subsidiary of AT&T Inc. that provides voice, video, data, and Internet telecommunications and professional services to businesses, consumers, and government agen ...

, as a Research Engineer (Applied Mathematician), New York City, New York. *1943 – 1963 Professor and Head of Department of Mathematics,

Polytechnic Institute of Brooklyn The New York University Tandon School of Engineering (commonly referred to as Tandon) is the engineering and applied sciences school of New York University. Tandon is the second oldest private engineering and technology school in the United Sta ...

, Brooklyn, New York City, New York.

Publications

*Campbell, GA, Foster, RM, ''Fourier Integrals for Practical Applications'', "Bell System Technical Journal", pp 639–707, 1928. *Pierce, BO, Foster. RM. "A Short Table of Integrals", Fourth Edition, Ginn and Company, pp 1–189, 1956.

References

1896 births American centenarians Men centenarians Scientists at Bell Labs American electronics engineers 20th-century American mathematicians Graph theorists Harvard College alumni 1998 deaths Polytechnic Institute of New York University faculty 20th-century American engineers {{US-mathematician-stub