Eero Urho Juhani Karhumäki (born 1949) is a Finnish

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, mathematical structure, structure, space, Mathematica ...

and

theoretical computer scientist Theoretical computer science is a subfield of computer science and mathematics that focuses on the abstract and mathematical foundations of computation. It is difficult to circumscribe the theoretical areas precisely. The ACM's Special Inter ...

known for his contributions to

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 with close connections to cognitive science and mathematical l ...

. He is a professor at the

University of Turku The University of Turku (, shortened ''UTU'') is a multidisciplinary public university with eight faculties located in the city of Turku in southwestern Finland. The university also has campuses in Rauma and Pori and research stations in Kevo ...

in southwestern

Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...

Biography

Karhumäki earned his doctorate from the

in 1976. In 1980–1985, he was a junior researcher of

Academy of Finland The Research Council of Finland (, ) is a governmental funding body for scientific research in Finland. Until August 2023, its official English-language name was Academy of Finland. It is based in Helsinki. Yearly, the council administers over ...

. Since 1986, he has held teaching positions at the

, attaining full professorship in 1998. In 1998–2015, Karhumäki was the head of the mathematics department at the

. He has authored altogether around 200 research papers. Karhumäki is a member of the

Finnish Academy of Science and Letters The Finnish Academy of Science and Letters (; ) is a Finnish learned society. It was founded in 1908 and is thus the second oldest academy in Finland. The oldest is the Finnish Society of Sciences and Letters, which was founded in 1838. Member ...

since 2000 and of

Academia Europaea The Academia Europaea is a pan-European Academy of humanities, letters, law, and sciences. The Academia was founded in 1988 as a functioning Europe-wide Academy that encompasses all fields of scholarly inquiry. It acts as co-ordinator of Europe ...

since 2006. A festschrift in his honour was published in 2009 as a special issue of

Theoretical Computer Science Theoretical computer science is a subfield of computer science and mathematics that focuses on the Abstraction, abstract and mathematical foundations of computation. It is difficult to circumscribe the theoretical areas precisely. The Associati ...

Research contributions

Karhumäki has been a member of the

Lothaire Lothaire is French masculine given name that is a modern form of the Germanic Chlothar (which is a blended form of Hlūdaz and Harjaz). People with this name include: Surname * Hubert Lothaire (1865 – 1929), Belgian military officer Given nam ...

group of mathematicians that developed the foundations of combinatorics of words. In 1991, jointly with Tero Harju, he solved the long-standing equivalence problem for multitape

finite 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 ...

in automata theory. Karhumäki contributed to different areas of

formal language theory In logic, mathematics, computer science, and linguistics, a formal language is a set of string (computer science), strings whose symbols are taken from a set called "#Definition, alphabet". The alphabet of a formal language consists of symbol ...

, such as word equations,

language equation Language is a structured system of communication that consists of grammar and vocabulary. It is the primary means by which humans convey meaning, both in spoken and signed forms, and may also be conveyed through writing. Human language is ch ...

s and descriptional complexity of finite automata.

References

External links

* * {{DEFAULTSORT:Karhumaki, Juhani Finnish mathematicians Finnish computer scientists University of Turku alumni Members of Academia Europaea Members of the Finnish Academy of Science and Letters People from Turku Living people 1949 births Theoretical computer scientists