Arkady D. Zakrevski
Arkadź D. Zakreŭski – scientific, scientific-organizational, pedagogical and social activities (1928–2014)
Arkadź D. Zakreŭski is the corresponding member of the National Academy of Sciences of Belarus, academician of the International Academy of Information, Information Processes and Technologies, doctor of technical sciences, professor, head (later – main researcher) of the Logical Design Laboratory of the United Institute for Informatics Problems of the National Academy of Sciences of Belarus.
A. Zakreŭski is a talented scientist, an outstanding Belarusian and Soviet cybernetics specialist in the field of applied discrete mathematics, computer science and logical design. He stood at the origins of cybernetics, he is the founder of one of the most famous schools of logical design in the Soviet Union and in the world.
A. Zakreŭski was born on May 22, 1928 in Leningrad into a family of employees. Having received the profession of a radio operator at the Krasnoyarsk vocational school of communications, he worked from 1943 to 1951 as a radio operator in the survey teams of Zheldorproekt in the Arctic regions, Siberia, Mongolia (Taimyr, Igarka, Norilsk, the Turukhan river, then Transbaikalia, Chita, Mongolia). In 1949 he passed exams for a secondary school course in Ulan Bator (Mongolia) and received a certificate of maturity.
In 1951, A. Zakreŭski became a student at the Faculty of Physics at Tomsk State University (TSU), two years later he transferred to the newly organized Faculty of Radiophysics and graduated with honors with a degree in physics and electronics. In 1956 he entered graduate school under Professor V.D. Kessenikh, taught at the university, selected a group of enthusiastic students and together with them began studying a new (not only within the walls of the university, but also in the USSR) science – cybernetics.
Having learned in 1957 that serial production of the Ural-1 computer was beginning in Penza, A. Zakreŭski took an active part in its receipt, installation and commissioning at TSU, and then, critically assessing this latest achievement of the USSR computer technology, proposed a project of an original computer with the same performance as the Ural-1 that required a hall of 100 m2 for its placement, but only on 18 triggers. More than one generation of cybernetics students later studied under this project not only at TSU, but also at the Sevastopol Instrument-Making Institute.
Having estimated from his own experience the complexity of solving logical-combinatorial problems and seeking ways to solve them, A. Zakreŭski proposes the L-machine - a logical extension of the Ural-1 computer, which increases its performance by several orders of magnitude in solving such problems. Making a mock-up of the L-machine became a topic of theses for the first cybernetics students of TSU.
In 1960 A. Zakreŭski defended his thesis for the degree of candidate of physical and mathematical sciences on the topic "Matrix method for synthesis of relay circuits." The quality of the dissertation is eloquently evidenced by the fact that its first opponent, doctor of technical sciences A. Sapozhnikov, having read out his review, suggested that the applicant should not be awarded the degree not of a candidate, but a doctor of sciences. The complexity of programming logic synthesis problems in machine codes led A. Zakreŭski to the conclusion that it was necessary to create a programming language, and in 1962 he developed a logical language for representing algorithms for the synthesis of relay devices LYaPAS – the first programming language for logic problems implemented on a computer.
The first monograph of A. Zakreŭski "The Algorithmic Language LYaPAS and Automation of the Synthesis of Discrete Automata" (1966) became the result of the fruitful scientific activity. Basing on the monograph, in 1967 the scientist defended his thesis for the degree of doctor of technical sciences at the Institute of Automation and Telemechanics of the USSR Academy of Sciences (Moscow). Interest in the LYaPAS language abroad was stimulated by the appearance of the English translation of the collection of scientific articles describing the LYaPAS language and algorithms for the synthesis of discrete automata presented in this language: "LYaPAS, A Programming Language for Logic and Coding Algorithms" (ed. By M. Gavrilov and A. Zakrevskij), ACM Monograph Series, New York, London, 1969. Programming systems for various types of computers were developed for the LYaPAS language. These systems have found wide application in many organizations of the USSR, as well as abroad: in Poland, Germany (East and West Germany), Czechoslovakia, Yugoslavia, USA.
In 1959-1971, A. Zakreŭski was an assistant, senior researcher, head of the Laboratory of Computing Devices of the Siberian Institute of Physics and Technology, professor, head of the Department of Mathematical Logic and Programming at TSU. He conducted research in the field of technical applications of logic at Tomsk State University and the Siberian Institute of Physics and Technology, laid the foundations of computer discrete mathematics and developed a technology for experimental statistical research of algorithms on a computer. In 1971 he published the fundamental monograph “Algorithms for the synthesis of discrete automata”, widely known in the USSR. The first system in the USSR for automatic synthesis of discrete automata was created under his leadership. The system was adopted by the Commission on Cybernetics under the Presidium of the USSR Academy of Sciences and operated in the 1970–1980s at many enterprises of the ministries of the electronic and radio industry.
In 1971, A. Zakreŭski with a group of employees moved to Minsk and organized a laboratory of system programming and logical synthesis at the Institute of Technical Cybernetics of the Academy of Sciences of the BSSR, which was later renamed the laboratory of logical design. In 1972 he was elected a corresponding member of the Academy of Sciences of the BSSR. For more than twenty years A. Zakreŭski was the head of the laboratory organized by him, then he transferred the management to his student, remaining the main researcher and supervisor of many scientific and scientific-technical topics and projects.
A characteristic feature of the scientific work of A. Zakreŭski is the combination of the wide coverage of the considered problem (up to the search for analogies in neighboring areas) with the rigor and depth of its research (with proposals of practically effective methods for its solution, often brought to algorithmic and sometimes software implementation). A distinctive feature of the scientific school of A. Zakreŭski was the development of a logical and combinatorial approach based on the formulation of design problems in the form of optimizational logical and combinatorial problems on functional and structural models of design objects. This approach made it possible to develop the theoretical foundations of cybernetics in various fields.
In this chapter, it is difficult to summarize the multifaceted scientific and organizational activities of A. Zakreŭski and evaluate his contribution to science. It is difficult even to list the fields of science into which he directed his inquisitive scientific interest. Therefore, we will confine ourselves to only a short list of the main areas of cybernetics, where he left the deepest mark.
1. Logical theory of discrete devices: application of the noise-immune Hamming code to the synthesis of reliable logic circuits; visual matrix method for minimizing Boolean functions; matrix logical equations apparatus for solving problems of analysis, synthesis and diagnostics of malfunctions of programmable logical matrices; effective methods for decomposition of Boolean functions and discrete automata, coding of internal states of synchronous and asynchronous automata. A. Zakreŭski proposed a matrix apparatus for logical analysis, synthesis and diagnostics of discrete devices based on programmable logical matrices, the results of these studies were presented in his monograph "Logical synthesis of cascade circuits" (Moscow: Fizmatlit, 1980).
2. Automation of programming logic problems: language and programming system LYaPAS, effective for logical and combinatorial problems, that found wide application in many organizations in the country and abroad (in Poland, East Germany, Czechoslovakia, Yugoslavia, West Germany, USA).
3. Automation of logical design: effective methods of minimization and implementation of fully and weakly defined Boolean functions of many variables; minimization of systems of Boolean functions in the class of Zhegalkin and Reed-Muller polynomials; methods of implementing systems of multivalued partial functions by polarized Reed-Muller polynomials, diagnosing constant faults in EXOR circuits, and a number of automated logic design systems introduced into production (CDB "Almaz" (Moscow), NIIEVM, SPA "Integral", etc.).
4. Logical foundations of intelligent systems: methods for solving large systems of logical equations, linear and nonlinear; methods for finding the shortest solutions of indefinite and incompatible systems of linear logical equations; generalization of theory methods of Boolean functions to finite predicates; methods of inductive and deductive inference in application to pattern recognition in the space of binary and multivalued features; identification of implicative patterns in these spaces; expert systems for logical pattern recognition.
5. Automation of design of logical control systems: language PRALU for description of parallel algorithms for logical control; methods of verification, modeling and implementation of parallel algorithms; concepts of parallel and sequential automata and methods for synthesis of logical control devices based on them; methods of composition and decomposition of parallel automata described in the PRALU language.
6. Combinatorial problems of discrete mathematics: computation technique for Boolean space, combinatorial basis of logical design – a complex of effective methods and programs for solving combinatorial problems over logical matrices and graphs, which have many useful practical interpretations; computing technique in the space of finite predicates, methods of their minimization and decomposition; highly efficient methods for solving systems of logical equations.
The results of theoretical studies of A. Zakreŭski formed the basis for a number of software systems for the automation of solving logical-combinatorial problems: logical design of discrete control devices in the VLSI basis; software and hardware implementation of parallel control algorithms and an expert logical recognition system.
The results of scientific research made by A. Zakreŭski are presented in more than 540 scientific publications, including 26 monographs (7 in English). He actively supported international scientific contacts, made reports, was a member of the organizational and program committees of various conferences, symposia and seminars, collaborated with scientists from Russia, Ukraine, the Baltic States, Poland, USA, Germany, Portugal. For scientific and organizational activities A. Zakreŭski was awarded with diplomas of the Supreme Soviet of the BSSR.
A. Zakreŭski was not only an outstanding scientist, but also an excellent teacher. He gave lecture courses of his own design in mathematical logic, discrete mathematics, probability theory, automata theory, graph theory, theory of Boolean functions, programming, methods of logical design and other disciplines at TSU (Tomsk), BSU and BSUIR (Minsk). He created a scientific school of logical design, more than three dozen of his graduate students became candidates (eight of them – doctors) of sciences. Branches of this school are successfully operating in Tomsk and Sevastopol. A. Zakreŭski was the permanent leader of the permanent scientific seminar on logical design in the UIIP NAS of Belarus. The seminar is well-known in the scientific community.
A. Zakreŭski successfully combined his scientific activity with solving scientific and organizational issues: he was a member of the councils for the defense of dissertations at the UIIP of the National Academy of Sciences of Belarus, the Belarusian State University, the Institute of Electronics of the Latvian Academy of Sciences (1980–1990); a member of the scientific ("Modeling of intellectual activity") councils of the UIIP; a member of the editorial boards of the journals "International Journal on Information Theories and Applications" (Sofia, Bulgaria), "Control systems and machines" (Kiev, Ukraine), "Applied discrete mathematics" (Tomsk, Russia), "Radioelectronics & Informatics" (Kharkov, Ukraine), "Informatics" (UIIP NAS of Belarus, Minsk), collection "Problems of information security" (BSU, Minsk). Several dozen monographs, annual collections of works on logic design and programming (1975–2001), materials of scientific and technical conferences (1975–1995) were published under his scientific editorship. About 30 articles and notes about his life and scientific activity were published.
The entire life of A. Zakreŭski was connected with science and was devoted to it, he worked until the last day of his life: in 2013, his monograph in English was published in the publishing house TUT Press, the next monograph was being prepared for publication, and a report to the conference was submitted.
A. Zakreŭski has earned recognition and authority not only as an outstanding researcher and leader, but also as an honest, fair and principled person. He was endowed with a phenomenal talent for providing theoretical foundations and elegant solutions to the most difficult problems in discrete mathematics, computer science and design of discrete devices. If we talk about the facets of his character, then the main ones are diligence, passion for scientific research, the desire to bring fundamental research to their implementation in design practice, firmness and uncompromising attitude. Talent and tireless work are the sources of his achievements and greatness as a scientist and a person with a capital letter. There will forever be a grateful memory of teacher and leader A. Zakreŭski in the hearts of students and his followers in the field of logical design.
The obtained results are reflected in 500 publications, including 23 monographs listed below.
Алгоритмический язык ЛЯПАС и автоматизация синтеза дискретных автоматов. Томск,1966;
LYaPAS: A programming language for logic and coding algorithms. Academic Press, N.-Y., L., 1969 (with M. A. Gavrilov);
Алгоритмы синтеза дискретных автоматов. М.,1971;
Логические уравнения. Мн.,1975;
Синтез асинхронных автоматов на ЭВМ. Мн.,1975 (у суаўтарстве);
Система программирования ЛЯПАС-М. Мн.;1978 (з М.Р. Торапавым);
Логический синтез каскадных схем. М.,1981; М.,2003;
Boolesche Gleichungen: Theorie, Anwendung, Algorithmen. VEB Verlag Technik, Berlin,1984 (mit D. Bochmann und Ch. Posthoff);
Логика распознавания. Мн.,1988, М.,2003 (дадатковае выданне);
Параллельные алгоритмы логического управления. Мн.,1999, М.,2003;
Полиномиальная реализация частичных булевых функций и систем. Мн.,2001, М.,2003 (з М.Р. Торапавым);
Основы логического проектирования. Книга 1. Комбинаторные алгоритмы дискретной математики. – Мн: ОИПИ НАН Беларуси, 2004 (з Ю.В. Патосіным і Л.Д.Чарамісінавай);
Основы логического проектирования. Книга 2. Оптимизация в булевом пространстве. – Мн: ОИПИ НАН Беларуси, 2004 (з Ю.В. Патосіным і Л.Д.Чарамісінавай);
Основы логического проектирования. Книга 3. Проектирование устройств логического управления. – Минск, ОИПИ НАН Беларуси, 2006 (з Ю.В. Патосіным і Л.Д.Чарамісінавай);
Логические основы проектирования дискретных устройств. – М.: Физматлит, 2007 (з Ю.В. Патосіным і Л.Д.Чарамісінавай);
Combinatorial algorithms of discrete mathematics. – TUT Press, 2008 (with Yu. Pottosin, L. Cheremisinova);
Optimization in Boolean space. – TUT Press, 2009 (with Yu. Pottosin, L. Cheremisinova);
Решение больших систем логических уравнений – Минск, ОИПИ НАН Беларуси, 2009;
Design of logical control devices, TUT Press, 2009 (with Yu. Pottosin, L. Cheremisinova).
