Eero Urho Juhani Karhumäki (born 1949) is a

Finnish Finnish may refer to: * Something or someone from, or related to Finland * Culture of Finland * Finnish people or Finns, the primary ethnic group in Finland * Finnish language, the national language of the Finnish people * Finnish cuisine See also ...

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 ...

and

theoretical computer scientist computer science (TCS) is a subset of general computer science and mathematics that focuses on mathematical aspects of computer science such as the theory of computation, lambda calculus, and type theory. It is difficult to circumscribe the th ...

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. The word ''automata'' comes from the Greek word αὐτόματο� ...

. He is a professor at the

University of Turku sv, Åbo universitet , latin_name = Universitas Aboensis , image_name = University of Turku.svg , motto = ''Vapaan kansan lahja vapaalle tieteelle'' , established = 1920 , type ...

Biography

Karhumäki earned his doctorate from the

in 1976. In 1980–1985, he was a junior researcher of Academy of Finland. 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 (Finnish ''Suomalainen Tiedeakatemia''; Latin ''Academia Scientiarum Fennica'') is a Finnish learned society. It was founded in 1908 and is thus the second oldest academy in Finland. The oldest is the Fi ...

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 Europea ...

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

Theoretical Computer Science computer science (TCS) is a subset of general computer science and mathematics that focuses on mathematical aspects of computer science such as the theory of computation, lambda calculus, and type theory. It is difficult to circumscribe the ...

Research contributions

Karhumäki has been a member of the Lothaire 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 o ...

in automata theory. Karhumäki contributed to different areas of

formal language theory In logic, mathematics, computer science, and linguistics, a formal language consists of words whose letters are taken from an alphabet and are well-formed according to a specific set of rules. The alphabet of a formal language consists of symb ...

, such as word equations,

language equation Language equations are mathematical statements that resemble numerical equations, but the variables assume values of formal languages rather than numbers. Instead of arithmetic operations in numerical equations, the variables are joined by language ...

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