Volodymyr Rwachev

Volodymyr Lohwynowytsch Rwatschow , Ukrainian Володимир Логвинович Рвачов , Russian Владимир Логвинович Рвачёв Vladimir Logwinowitsch Rwatschow , English transcription Vladimir Logvinovich Rvachev, (* 21st October 1926 in Chihirin , Ukrainian SSR ; † 26. April 2005 in Kharkiv , Ukraine ) was a Soviet -ukrainischer Applied mathematician and engineer.

biography

Rwachev was the son of a teacher, younger brother of Kateryna Yushchenko, and studied from 1943 at the Polytechnic Institute in Kharkiv , which was interrupted by the German occupation and military service in the Soviet army . After the Second World War, he continued his studies in Lviv , graduating in 1952 and receiving his doctorate in 1955 in elasticity theory. He then taught mathematics at the Pedagogical Institute in Berdyansk until 1963 . In 1961 he completed his habilitation (Russian doctorate) at the Institute of Mechanics of the Soviet Academy of Sciences and became a professor. From 1963 to 1967 he was head of the numerical mathematics department at the Institute of Radioelectronics in Kharkiv and then head of the applied mathematics and computer methods department at the Institute for Problems in Mechanical Engineering of the Ukrainian Academy of Sciences.

With his R functions ( Rwatschow functions ) he implemented Boolean algebra (mathematical logic) in the definition of real functions. They are real functions that don't change sign if none of their arguments change sign. Depending on the sign, the Boolean values ​​1 or 0 (true, false) can be assigned to them. Rwatschow introduced the functions as early as 1968 and wrote a monograph on them in 1982, but they did not become internationally known until the English translation in 1988. The functions were useful in expanding variational methods to areas with complicated margins. The geometric information about the edges can be converted into analytical information ( boundary value problems with R functions).

With colleagues and students he published 17 monographs and around 500 scientific articles.

In 1972 he became a corresponding and in 1978 a full member of the Ukrainian Academy of Sciences .

Fonts

• Theory of R-functions and some applications (Russian), Kiev 1982
• with NS Sinekop: Method of R-Functions in Elasticity and Plasticity Theory (Russian), Kiev 1990
• with Sheiko, Sinekop: R-functions in Boundary Value Problems in Mechanics, Applied Mechanics Reviews, Volume 48, 1995, pp. 151-188

literature

• Karl-Eugen Kurrer : The History of the Theory of Structures. Searching for Equilibrium , Ernst & Sohn 2018, p. 1055 (biography), ISBN 978-3-433-03229-9 .

Web links

• mathnet.ru