László "Les" Bélády (April 29, 1928, in

Budapest Budapest is the Capital city, capital and List of cities and towns of Hungary, most populous city of Hungary. It is the List of cities in the European Union by population within city limits, tenth-largest city in the European Union by popul ...

– November 6, 2021) was a Hungarian

computer scientist A computer scientist is a scientist who specializes in the academic study of computer science. Computer scientists typically work on the theoretical side of computation. Although computer scientists can also focus their work and research on ...

notable for devising the Bélády's Min theoretical memory caching

algorithm In mathematics and computer science, an algorithm () is a finite sequence of Rigour#Mathematics, mathematically rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algo ...

in 1966 while working at

IBM Research IBM Research is the research and development division for IBM, an American Multinational corporation, multinational information technology company. IBM Research is headquartered at the Thomas J. Watson Research Center in Yorktown Heights, New York ...

. He also demonstrated the existence of a Bélády's anomaly. During the 1980s, he was the

editor-in-chief An editor-in-chief (EIC), also known as lead editor or chief editor, is a publication's editorial leader who has final responsibility for its operations and policies. The editor-in-chief heads all departments of the organization and is held accoun ...

of the

IEEE Transactions on Software Engineering The ''IEEE Transactions on Software Engineering'' is a monthly peer-reviewed scientific journal published by the IEEE Computer Society. It was established in 1975 and covers the area of software engineering. It is considered the leading journal in ...

Education

Bélády earned B.S. in

Mechanical Engineering Mechanical engineering is the study of physical machines and mechanism (engineering), mechanisms that may involve force and movement. It is an engineering branch that combines engineering physics and engineering mathematics, mathematics principl ...

, then an

M.S. A Master of Science (; abbreviated MS, M.S., MSc, M.Sc., SM, S.M., ScM or Sc.M.) is a master's degree. In contrast to the Master of Arts degree, the Master of Science degree is typically granted for studies in sciences, engineering and medicine ...

Aeronautical Engineering Aerospace engineering is the primary field of engineering concerned with the development of aircraft and spacecraft. It has two major and overlapping branches: aeronautical engineering and astronautical engineering. Avionics engineering is s ...

at the Technical University of Budapest in 1950.

Life and career

He left Hungary after the

Hungarian Revolution of 1956 The Hungarian Revolution of 1956 (23 October – 4 November 1956; ), also known as the Hungarian Uprising, was an attempted countrywide revolution against the government of the Hungarian People's Republic (1949–1989) and the policies caused by ...

. Then he worked as a draftsman at

Ford Motor Company Ford Motor Company (commonly known as Ford) is an American multinational corporation, multinational automobile manufacturer headquartered in Dearborn, Michigan, United States. It was founded by Henry Ford and incorporated on June 16, 1903. T ...

in Cologne and as an aerodynamics engineer at

Dassault Groupe Industriel Marcel Dassault SAS (; also GIM Dassault or Dassault Group) is a French corporate group established in 1929 with the creation of Société des Avions Marcel Bloch (now Dassault Aviation) by Marcel Dassault, later led by his so ...

in Paris. In 1961, he immigrated to the United States. In the 1960s and 1970s, he primarily lived in

New York City New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive w ...

with stints in

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

and

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

, where he joined

International Business Machines International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

and did early work in

operating systems An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

virtual machine In computing, a virtual machine (VM) is the virtualization or emulator, emulation of a computer system. Virtual machines are based on computer architectures and provide the functionality of a physical computer. Their implementations may involve ...

architectures, program behavior modeling,

memory management Memory management (also dynamic memory management, dynamic storage allocation, or dynamic memory allocation) is a form of Resource management (computing), resource management applied to computer memory. The essential requirement of memory manag ...

computer graphics Computer graphics deals with generating images and art with the aid of computers. Computer graphics is a core technology in digital photography, film, video games, digital art, cell phone and computer displays, and many specialized applications. ...

, Asian character sets, and

data security Data security or data protection means protecting digital data, such as those in a database, from destructive forces and from the unwanted actions of unauthorized users, such as a cyberattack or a data breach. Technologies Disk encryption ...

.Oral history interview with László A. Bélády

Charles Babbage Institute The IT History Society (ITHS) is an organization that supports the history and scholarship of information technology by encouraging, fostering, and facilitating archival and historical research. Formerly known as the Charles Babbage Foundation, ...

, University of Minnesota. From 1961–1981, he worked at

IBM International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

Corp. at the

Thomas J. Watson Research Center The Thomas J. Watson Research Center is the headquarters for IBM Research. Its main laboratory is in Yorktown Heights, New York, 38 miles (61 km) north of New York City. It also operates facilities in Cambridge, Massachusetts and Albany, ...

, where he worked as

program manager Program Manager is the shell of Windows 3.x and Windows NT 3.x operating systems. This shell exposed a task-oriented graphical user interface (GUI), consisting of ''icons'' ( shortcuts for programs) arranged into ''program groups''. It replaced ...

for

software Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications. The history of software is closely tied to the development of digital comput ...

technology. In his later years at

, he was responsible for

software engineering Software engineering is a branch of both computer science and engineering focused on designing, developing, testing, and maintaining Application software, software applications. It involves applying engineering design process, engineering principl ...

worldwide until leaving for

Tokyo Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...

to create its software research lab. In 1981, he worked as manager of

at Japan Science Institute for two years. In 1984, he joined the

Microelectronics and Computer Technology Corporation Microelectronics and Computer Technology Corporation, originally the Microelectronics and Computer Consortium and widely seen by the acronym MCC, was the first, and at one time one of the largest, computer industry research and development c ...

in Austin and founded its Software Technology Program. He focused the program on creating advanced technology for aiding the distributed design of large complex software systems. From 1991 to 1998, he served as president and CEO of Mitsubishi Electric Research Laboratories, Inc. (MERL). He has been in various University advisory roles including a member of the computer science advisory board at the

University of Colorado at Boulder The University of Colorado Boulder (CU Boulder, CU, or Colorado) is a Public university, public research university in Boulder, Colorado, United States. Founded in 1876, five months before Colorado became a Federated state, state, it is the fla ...

and foreign member of the

Hungarian Academy of Sciences The Hungarian Academy of Sciences ( , MTA) is Hungary’s foremost and most prestigious learned society. Its headquarters are located along the banks of the Danube in Budapest, between Széchenyi rakpart and Akadémia utca. The Academy's primar ...

. In his retirement he spent much of his time in

and

Austin Austin refers to: Common meanings * Austin, Texas, United States, a city * Austin (given name), a list of people and fictional characters * Austin (surname), a list of people and fictional characters * Austin Motor Company, a British car manufac ...

Attainment

Bélády is known for the "Belady Algorithm", the OPT (or MIN)

Page Replacement Algorithm In a computer operating system that uses paging for virtual memory management, page replacement algorithms decide which memory pages to page out, sometimes called swap out, or write to disk, when a page of memory needs to be allocated. Page repl ...

. He co-designed and built

IBM M44/44X The IBM M44/44X was an experimental computer system from the mid-1960s, designed and operated at IBM's Thomas J. Watson Research Center at Yorktown Heights, New York. It was based on a modified IBM 7044 (the 'M44'), and simulated multiple 7044 vi ...

, an experimental machine which is the first computer with multiple virtual machine organization. He is co-founder of an industrial research consortium, the MCC. Bélády also participated in the design of the earliest commercial

time-sharing In computing, time-sharing is the Concurrency (computer science), concurrent sharing of a computing resource among many tasks or users by giving each Process (computing), task or User (computing), user a small slice of CPU time, processing time. ...

systems, the TSS-67.

Awards

* 1969 & 1973: IBM Outstanding Contribution Awards * 1988: IEEE "for contributions to the design of large software systems" * 1990: J. D. Warnier Prize for Excellence in Information

Publications

* Belady, Laszlo A., "A Study of Replacement Algorithms for a Virtual Storage Computer,"

IBM Systems Journal ''IBM Journal of Research and Development'' is a former, peer-reviewed bimonthly scientific journal covering research on information systems. This Journal has ceased production in 2020. According to the ''Journal Citation Reports'' in 2019, the jo ...

, Vol. 5, No. 2 June 1966, pp. 78–10. * Belady, Laszlo A., and Meir L. Lehman, Program Evolution, Processes of Software Change,

Academic Press Academic Press (AP) is an academic book publisher founded in 1941. It launched a British division in the 1950s. Academic Press was acquired by Harcourt, Brace & World in 1969. Reed Elsevier said in 2000 it would buy Harcourt, a deal complete ...

London London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...

, 1985.

References

{{DEFAULTSORT:Belady, Laszlo 1928 births 2021 deaths Hungarian computer scientists Computer systems researchers American software engineers Businesspeople in software Hungarian chief executives IBM employees Mitsubishi Electric people University of Colorado Boulder faculty Budapest University of Technology and Economics alumni Hungarian emigrants to the United States Hungarian expatriates in Germany Hungarian expatriates in France Scientists from Budapest