Seppo Linnainmaa
Seppo Linnainmaa is a Finnish mathematician and computer scientist whose 1970 master's thesis described reverse-mode automatic differentiation, the method behind modern backpropagation. He studied mathematics at the University of Helsinki, completed a computer science doctorate there in 1974, and held university posts and visiting appointments in the United States. He served as a research professor at VTT and chaired the Finnish Artificial Intelligence Society; his thesis methods helped drive a neural-network breakthrough. As of October 2026, he is an emeritus professor whose publications span numerical analysis, digital image processing and artificial intelligence.
Timeline
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1945–1964
Pori and Porin Lyseo
He is born in Pori in 1945 and completes the matriculation examination at Porin Lyseo in 1964.
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1970–1976
Reverse-mode thesis and a doctorate
A Finnish mathematician and computer scientist, he earns mathematics degrees at the University of Helsinki and serves as an assistant there from 1970 to 1976. His 1970 master's thesis describes reverse-mode automatic differentiation, the method behind modern backpropagation. In 1974, he completes a computer science doctorate at Helsinki with a dissertation on improving the accuracy of floating-point sums.
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1975–1982
University appointments in Finland
In 1975, he becomes a docent at the University of Joensuu; in 1976, he becomes a docent and senior assistant at the University of Helsinki. From 1977 to 1982, he serves as an assistant professor at Lappeenranta University of Technology.
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1979–1985
Visiting posts in the United States
From 1979 to 1980, he visits the University of California, Berkeley, as a visiting researcher. In 1984, he becomes a visiting professor at the University of Maryland through 1985.
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1982–1989
Research at VTT
He joins VTT as a special researcher in 1982 and holds the role through 1989. His 1970s thesis methods help drive a breakthrough in neural networks, and VTT has several AI research teams by the 1980s.
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1986–1989
Finnish AI Society chair
From 1986 to 1989, he chairs the Finnish Artificial Intelligence Society.
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1989–2007
Research professor at VTT
He becomes a research professor at VTT in 1989 and holds the post through 2007. From 1995 to 2005, he also serves as a research manager at VTT. He sits on ERCIM's board from 1993 to 2005.
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As of October 2026
Professor emeritus
As of October 2026, he is an emeritus professor whose publications span numerical analysis, digital image processing and artificial intelligence.
Career
- 1993–2005European Research Consortium for Informatics and MathematicsBoard Member
- 1984–1985University of MarylandVisiting Professor
- 1983–1991Ministry of Economic Affairs and Employment
- 1982–2007Technical Research Centre of FinlandSpecial Researcher, Research Professor
- 1979–1980University of California, BerkeleyVisiting Researcher
- 1977–1982Lappeenranta-Lahti University of TechnologyAssistant Professor
- From 1975University of JoensuuDocent
- 1970–1976University of HelsinkiAssistant, Docent and Senior Assistant
Education
- 1974University of HelsinkiMathematics degree
Most-cited works
- Taylor expansion of the accumulated rounding error
- Pose determination of a three-dimensional object using triangle pairs
- Software for Doubled-Precision Floating-Point Computations
- EPO: A Knowledge Based System for Wood Procurement Management
- Analysis of some known methods of improving the accuracy of floating-point sums
Colleagues
- Kimmo KoskenniemiUniversity of Helsinki, 1970–1976
Aapo HyvärinenUniversity of Helsinki, 2022–2025- Hannu ToivonenUniversity of Helsinki, 2022–2025
- Jaakko T. AstolaLappeenranta-Lahti University of Technology, 1979–1982
John OhalaUniversity of California, Berkeley, 1979–1980
Ben ShneidermanUniversity of Maryland, 1984–1985
Sources and credits
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