View source for Athanasios Papoulis

{{Short description|Greek-American engineer and applied mathematician (1921–2002)}}
{{Infobox scientist
| name              = Athanasios Papoulis
| image             = Athanasios Papoulis, circa 1989.png <!--(filename only, i.e. without "File:" prefix)-->
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| caption           = Athanasios Papoulis, {{abbr|c.|circa}} 1989
| birth_date        = 1921<!--{{birth date |YYYY|MM|DD}}-->
| birth_place       = [[Turkey]]
| death_date        = {{death date and age |2002|4|25 |1921}}
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| alma_mater        = [[University of Pennsylvania]]<br>[[National Technical University of Athens]]
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| doctoral_advisor  = [[John Robert Kline]]
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}}

'''Athanasios Papoulis'''<ref name="PapoulisAward">[http://www.ieee.li/awards/papoulis.htm Papoulis IEEE Award]</ref> ({{langx|el|Αθανάσιος Παπούλης}}; 1921 &ndash; April 25, 2002) was a [[Greek American|Greek]]-[[United States|American]] [[engineer]] and applied [[mathematician]].

==Life==
Papoulis was born in modern day [[Turkey]] in 1921, and his family was moved to [[Athens]], [[Greece]] in 1922 as a consequence of the [[Population exchange between Greece and Turkey]]. He earned his undergraduate degree from [[National Technical University of Athens]]. In 1945, he stowed away on a boat to escape the impending [[Greek Civil War]] and settled in the United States. He studied  under the supervision of [[John Robert Kline]] at the [[University of Pennsylvania]] and earned his Ph.D. in Mathematics in 1950. His dissertation was titled ''On the Strong Differentiation of the Indefinite Integral.''<ref>{{MathGenealogy|id=36180}}</ref>

He married Caryl Engwall in New York, New York in 1953, and had five children: Irene, Helen, James, Ann, and Mary. In 1952, after teaching briefly at [[Union College]], he became a faculty member at the Polytechnic Institute of Brooklyn (now [[Polytechnic Institute of New York University]]), where he earned the distinction of University Professor.<ref>[http://www.poly.edu/news/archives/news2/?id=771 Announcement of Death].</ref>

===Studies===
Papoulis contributed in the areas of [[signal processing]], [[information theory|communications]], and [[signal theory|signal]] and [[system theory]]. His classic book ''Probability, Random Variables, and Stochastic Processes''<ref name="Pap">{{cite book |first1=Athanasios |last1=Papoulis |first2=S. Unnikrishna |last2=Pillai |title=Probability, Random Variables and Stochastic Processes |edition=4th |location=Boston |publisher=McGraw Hill |year=2002 |isbn=0-07-366011-6 }}</ref> is used as a textbook in many graduate-level probability courses in [[electrical engineering]] departments all over the world.

{{quotation|Two classic texts aimed at [engineering] practitioners were [first] published in 1965... [One was] Athanasios Papoulis' ''Probability, Random Variables, and Stochastic Processes''... These books popularized a pedagogy that balanced rigor and intuition.<ref>{{cite book |first=R. J. II |last=Marks |title=Handbook of Fourier Analysis and Its Applications |publisher=Oxford University Press |year=2009 |page=vi }}</ref>}}
By staying away from complete mathematical rigor while emphasizing the physical and engineering interpretations of [[probability]], Papoulis's book gained wide popularity.

===Theory===
Athanasios Papoulis specialized in engineering mathematics, his work covers probability, statistics, and estimation in the application of these fields to modern engineering problems. Papoulis also taught and developed subjects such as [[stochastic simulation]], [[Standard deviation|mean square estimation]], likelihood tests, [[Principle of maximum entropy|maximum entropy methods]], [[Monte Carlo method]], [[Diffraction|spectral representations]] and estimation, [[Statistical sampling|sampling theory]], [[bispectrum]] and system identification, [[cyclostationary process]]es, deterministic signals in noise (part of [[Deterministic system (mathematics)|deterministic systems]] and [[dynamical system]] studies), [[wave optics]] and the [[Wiener filter|Wiener]] and [[Kalman filter]]s.

====Contributions====
* Papoulis's generalization of the sampling theorem<ref>{{cite journal |first=A. |last=Papoulis |title=Generalized Sampling Expansion |journal=IEEE Transactions on Circuits and Systems |volume=24 |issue=11 |pages=652–654 |year=1977 |doi=10.1109/TCS.1977.1084284 }}</ref> unified many variations of the [[Nyquist–Shannon sampling theorem]] into one theorem.<ref>{{cite journal |first1=R. F. |last1=Hoskins |first2=J. De Sousa |last2=Pinto |title=Generalized Sampling Expansions in the Sense of Papoulis |journal=SIAM Journal on Applied Mathematics |volume=44 |issue=3 |year=1984 |pages=611–617 |doi=10.1137/0144043 }}</ref><ref>{{cite journal |first1=J. L. |last1=Brown |first2=S. D. |last2=Cabrera |title=On well-posedness of the Papoulis generalized sampling expansion |journal=IEEE Transactions on Circuits and Systems |year=1991 |volume=38 |issue=5 |pages=554–556 |doi=10.1109/31.76494 }}</ref>
* The [[Papoulis–Gerchberg algorithm]]<ref>{{cite journal |first=A. |last=Papoulis |title=A new method of image restoration |journal=Joint Services Technical Activity Report |volume=39 |year=1973–1974 }}</ref><ref>{{cite journal |first=R. W. |last=Gerchberg |title=Super-resolution through error energy reduction |journal=Opt. Acta |volume=21 |issue=9 |pages=709–720 |year=1974 |doi=10.1080/713818946 |bibcode=1974AcOpt..21..709G }}</ref><ref>{{cite journal |first=A. |last=Papoulis |title=A new algorithm in spectral analysis and bandlimited extrapolation |journal=IEEE Transactions on Circuits and Systems |volume=22 |issue=9 |pages=735–742 |year=1975 |doi=10.1109/TCS.1975.1084118 }}</ref> is an iterative signal restoration algorithm that has found widespread use in signal and image processing.<ref>{{cite book |first=Peter A. |last=Jansson |title=Deconvolution of Images and Spectra |edition=Second |publisher=Academic Press |year=1996 |pages=490–494 |isbn=0-12-380222-9 }}</ref><ref>R.J. Marks II, op.cit., pp. 477–482</ref>
* "Papoulis's eloquent proof"<ref>R.J. Marks II, Ibid, p. 223</ref> of the conventional [[sampling theorem]]<ref>{{cite book |first=Athanasios |last=Papoulis |title=Signal Analysis |publisher=McGraw-Hill |year=1977 |isbn=0-07-048460-0 }}</ref> requires only two equations.

==Bibliography==
* ''The Fourier Integral and its Applications'' by Papoulis, Athanasios, McGraw-Hill Companies (June 1, 1962), {{isbn|0-07-048447-3}}, {{LCCN|62-10211}}.
* ''Probability, Random Variables, and Stochastic Processes'' by Papoulis, Athanasios 1965. McGraw-Hill Kogakusha, Tokyo, 9th edition, {{isbn|0-07-119981-0}}
* ''Signal Analysis'' by Athanasios Papoulis Publisher: McGraw-Hill Companies (May 1977) {{isbn|0-07-048460-0}} {{isbn|978-0070484603}}
* ''Systems and Transforms With Applications in Optics'' by Athanasios Papoulis Publisher: Krieger Pub Co (June 1981) {{isbn|0-89874-358-3}} {{isbn|978-0898743586}}
* ''Probability and Statistics'' by Athanasios Papoulis Publisher: Prentice Hall (September 1989) {{isbn|0137116985}} {{isbn|978-0137116980}}
* ''Circuits and Systems – A modern approach'' by Athanasios Papoulis Publisher: Holt, Rinehart and Winston, Inc. (1980) {{isbn|0030560977}}

==References==
{{Reflist}}

==External links==
*[http://www.ieee.li/awards/papoulis.htm IEEE Athanasios Papoulis Award for Excellence in Engineering and Technology Education]
*[http://www.ieee.li/awards/index.htm The Athanasios Papoulis Award, one of the IEEE LI Section Awards]

{{IEEE James H. Mulligan, Jr. Education Medal}}

{{Authority control}}

{{DEFAULTSORT:Papoulis, Athanasios}}
[[Category:20th-century Greek mathematicians]]
[[Category:20th-century American mathematicians]]
[[Category:Greek engineers]]
[[Category:20th-century American engineers]]
[[Category:Greek emigrants to the United States]]
[[Category:Greeks from the Ottoman Empire]]
[[Category:1921 births]]
[[Category:2002 deaths]]
[[Category:Monte Carlo methodologists]]
[[Category:National Technical University of Athens alumni]]
[[Category:Polytechnic Institute of New York University faculty]]
[[Category:Emigrants from the Ottoman Empire to Greece]]
[[Category:Engineers from Athens]]