Sergey Vsevolodovich Yablonsky (

Russian Russian(s) refers to anything related to Russia, including: *Russians (, ''russkiye''), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries *Rossiyane (), Russian language term for all citizens and peo ...

: Серге́й Все́володович Ябло́нский, 6 December 1924 – 26 May 1998) was a

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

and

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

, one of the founders of the Soviet school of mathematical cybernetics and

discrete mathematics Discrete mathematics is the study of mathematical structures that can be considered "discrete" (in a way analogous to discrete variables, having a bijection with the set of natural numbers) rather than "continuous" (analogously to continuous f ...

. He is the author of a number of classic results on synthesis, reliability, and classification of

control systems A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial c ...

(russian: Управляющие системы), the term used in the

USSR The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nationa ...

and

for a generalization of

finite state automata A finite-state machine (FSM) or finite-state automaton (FSA, plural: ''automata''), finite automaton, or simply a state machine, is a mathematical model of computation. It is an abstract machine that can be in exactly one of a finite number o ...

Boolean circuits In computational complexity theory and circuit complexity, a Boolean circuit is a mathematical model for combinational digital logic circuits. A formal language can be decided by a family of Boolean circuits, one circuit for each possible input ...

and multi-valued logic circuits. Yablonsky is credited for helping to overcome the

pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and e ...

from Soviet ideologists against the term and the discipline of

cybernetics Cybernetics is a wide-ranging field concerned with circular causality, such as feedback, in regulatory and purposive systems. Cybernetics is named after an example of circular causal feedback, that of steering a ship, where the helmsperson m ...

and establishing what in the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

was called mathematical cybernetics as a separate field of

mathematics 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 ...

. Yablonsky and his students were ones of the first in the world to raise the issues of potentially inherent unavoidability of the brute force search for some problems, the precursor of the

P = NP problem The P versus NP problem is a major unsolved problem in theoretical computer science. In informal terms, it asks whether every problem whose solution can be quickly verified can also be quickly solved. The informal term ''quickly'', used abov ...

, though Gödel's letter to

von Neumann Von Neumann may refer to: * John von Neumann (1903–1957), a Hungarian American mathematician * Von Neumann family * Von Neumann (surname), a German surname * Von Neumann (crater), a lunar impact crater See also

* Von Neumann algebra * Von Ne ...

, dated 20 March 1956 and discovered in 1988, may have preceded them.

Biography

Childhood

Yablonsky was born in

Moscow Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 million ...

, to the family of a professor of mechanics. His mathematical talents became apparent in early age. In 1940 he became the winner of the sixth Moscow secondary school

mathematical olympiad Mathematics competitions or mathematical olympiads are competitive events where participants complete a math test. These tests may require multiple choice or numeric answers, or a detailed written solution or proof. International mathematics compe ...

War

In August 1942, after completing his first year at

Moscow State University M. V. Lomonosov Moscow State University (MSU; russian: Московский государственный университет имени М. В. Ломоносова) is a public research university in Moscow, Russia and the most prestigious ...

's Faculty of Mechanics and Mathematics, Yablonsky, then 17, went to serve in the

Soviet Army uk, Радянська армія , image = File:Communist star with golden border and red rims.svg , alt = , caption = Emblem of the Soviet Army , start_date ...

, fighting in the

second world war World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

as a member of the tank brigade 242. For his service he was awarded two

Orders of the Patriotic War The Order of the Patriotic War (russian: Орден Отечественной войны, Orden Otechestvennoy voiny) is a Soviet military decoration that was awarded to all soldiers in the Soviet armed forces, security troops, and to partisan ...

, two Orders of the Red Star,

Order of Glory Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

of the 3rd class, and numerous medals. He returned to his study after the war has ended in 1945 and went on to graduate with distinction.

Post-war period

Yablonsky graduated the Faculty of Mechanics and Mathematics of Moscow State University in 1950. During his student years he worked under supervision of

Nina Bari Nina Karlovna Bari (russian: Нина Карловна Бари; 19 November 1901 – 15 July 1961) was a USSR, Soviet mathematician known for her work on trigonometric series.

. This collaboration resulted in his first research paper, "On the converging sequences of continuous functions" (1950). He joined the graduate program of the Faculty of Mechanics and Mathematics in 1950 where his advisor was

Pyotr Novikov Pyotr Sergeyevich Novikov (russian: Пётр Серге́евич Но́виков; 15 August 1901, Moscow, Russian Empire – 9 January 1975, Moscow, Soviet Union) was a Soviet mathematician. Novikov is known for his work on combinatorial proble ...

. There Yablonsky's research was on the issues of the expressibility in mathematical logic. He approached this problem in terms of the theory of k-valued discrete functions. Among the problems that were addressed in his PhD thesis titled "Issues of functional completeness in k-valued calculus" (1953) is the definitive answer to the question of completeness in 3-valued logic. Starting from 1953, Yablonsky worked at the Department of Applied Mathematics of

Steklov Institute of Mathematics Steklov Institute of Mathematics or Steklov Mathematical Institute (russian: Математический институт имени В.А.Стеклова) is a premier research institute based in Moscow, specialized in mathematics, and a part ...

, that in 1966 became the separate Institute of Applied Mathematics. Over the period of the 1950s and 1960s, together with

Alexey Lyapunov Alexey Andreevich Lyapunov (russian: Алексе́й Андре́евич Ляпуно́в; 25 September 1911 – 23 June 1973) was a Soviet mathematician and an early pioneer of computer science. One of the founders of Soviet cybernetic ...

, Yablonsky organized the seminar on cybernetics, showing his support to the new field of mathematics that had been a subject of a significant

controversy Controversy is a state of prolonged public dispute or debate, usually concerning a matter of conflicting opinion or point of view. The word was coined from the Latin ''controversia'', as a composite of ''controversus'' – "turned in an opposite d ...

fueled by Soviet ideologists. He actively participated in the creation of the periodical publication Problems of Cybernetics, with Lyapunov as its first editor-in-chief. Yablonsky succeeded Lyapunov as the editor-in-chief of Problems of Cybernetics in 1974 (the publication changed its name to Mathematical Issues of Cybernetics in 1989). In 1966 Yablonsky (together with Yuri Zhuravlyov and Oleg Lupanov) was awarded Lenin Prize for their work on the theory of control systems (in the discrete-mathematical sense, as explained above). In 1968 Yablonsky was elected a corresponding member of the

Academy of Sciences of the Soviet Union The Academy of Sciences of the Soviet Union was the highest scientific institution of the Soviet Union from 1925 to 1991, uniting the country's leading scientists, subordinated directly to the Council of Ministers of the Soviet Union (until 1946 ...

(division of mathematics). Yablonsky played an active role in the creation of the Faculty of Computational Mathematics and Cybernetics at

in 1970. In 1971 he became the founding head of the department of mathematical cybernetics (initially department of

automata theory Automata theory is the study of abstract machines and automata, as well as the computational problems that can be solved using them. It is a theory in theoretical computer science. The word ''automata'' comes from the Greek word αὐτόματο� ...

and

mathematical logic Mathematical logic is the study of logic, formal logic within mathematics. Major subareas include model theory, proof theory, set theory, and recursion theory. Research in mathematical logic commonly addresses the mathematical properties of for ...

) at the Faculty of Computational Mathematics and Cybernetics.Яблонский Biography of S. V. Yablonsky at the website of the department of Mathematical Cybernetics, Moscow State University

References

{{DEFAULTSORT:Yablonsky, Sergey 1924 births 1998 deaths Corresponding Members of the USSR Academy of Sciences Corresponding Members of the Russian Academy of Sciences Moscow State University alumni Academic staff of Moscow State University Academic staff of the Moscow Institute of Physics and Technology Russian computer scientists Soviet computer scientists Soviet mathematicians 20th-century Russian mathematicians Burials in Troyekurovskoye Cemetery