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Sami Erol Gelenbe (born 22 August 1945) is a Turkish-French computer scientist, electronic engineer and applied mathematician who is professor in Computer-Communications at Imperial College. Known for pioneering the field of modelling and performance evaluation of computer systems and networks throughout Europe, he invented the random neural network and the eponymous G-networks. His many awards include the ACM SIGMETRICS[3] Life-Time Achievement Award, and the in Memoriam Dennis Gabor Award[4] of the Hungarian Academy of Sciences.

Erol Gelenbe
Erol Gelenbe Imperial College 2010 graduations.jpg
Born (1945-08-22) 22 August 1945 (age 73)[1]
Alma materMiddle East Technical University
Polytechnic Institute of New York University
Sorbonne Université (UPMC)
Known forG-networks
Random neural network
AwardsMustafa Prize
Scientific career
FieldsComputer science
Electrical engineering
Applied mathematics
InstitutionsUniversity of Liège
Paris-Sud 11 University
New Jersey Institute of Technology
Duke University
University of Central Florida
Imperial College
ThesisStochastic automata with structural restrictions (1970)
Doctoral advisorEdward J. Smith
Jacques-Louis Lions
InfluencesJacques-Louis Lions
Michael O. Rabin
Peter Whittle



Gelenbe was born in Istanbul in 1945, to Yusuf Ali Gelenbe, a descendant of the 18th-century Ottoman mathematician Gelenbevi Ismail Efendi, and Maria Sacchet Gelenbe from Cesiomaggiore, Belluno, Italy. After a childhood spent in Istanbul and Alexandria (Egypt), he graduated from Ankara Koleji in 1962 and the Middle East Technical University, Ankara in 1966, where he won the K.K. Clarke Research Award for an undergraduate thesis on "partial flux switching magnetic memory systems".[5] Awarded a Fulbright Fellowship, he continued his studies at Polytechnic University, where he completed a master's degree and a PhD thesis on "Stochastic automata with structural restrictions", under the supervision of Edward J. Smith.[6]

After graduation he joined the University of Michigan as an assistant professor. In 1972, on leave from Michigan, he founded the Modeling and Performance Evaluation of Computer Systems research group at INRIA (France), and was a visiting associate professor at the University of Paris 13 University. In 1971 he was elected to a Chair in Computer Science at the University of Liège in Belgium, where he joined Professor Danny Ribbens in 1973, while remaining a research director at INRIA. In 1973, he was awarded a Doctorat d'État ès Sciences Mathématiques from the Paris VI University with a thesis on "Modèlisation des systèmes informatiques", under Jacques-Louis Lions. He remained a close friend of Professor Ribbens and of the University of Liège, and in 1979, he moved to the Paris-Sud 11 University, where he co-founded the Laboratoire de Recherche en Informatique and its PhD Program, before joining Paris Descartes University in 1986 to found the Ecole des Hautes Etudes en Informatique.

Gelenbe was appointed New Jersey State Endowed Chair Professor at the New Jersey Institute of Technology from 1991 to 1993, and then in 1993 he was appointed to Duke University where he was the Nello L. Teer Chair Professor and Head of the Electrical and Computer Engineering Department until 1998 when he moved to the University of Central Florida, and founded the School of Electrical Engineering and Computer Science[7] and created the Harris Corporation Engineering Centre [8]

In 2003, Gelenbe was offered a Chair at Imperial College London as the Dennis Gabor Professor in Computer and Communication Networks[9][10] and Head of Intelligent Systems and Networks, from which he retired in 2019. He is now a Professor in the Institute of Theoretical and Applied Informatics (IITIS)[11] of the Polish Academy of Sciences.[12]

Notable contributionsEdit

Gelenbe has invented the Random neural network model, as well as the G-network which is used to analyze dynamic resource allocation in interconnected systems. He has pioneered research concerning the performance of multiprogramming computer systems, virtual memory management, data base reliability optimisation, distributed systems and network protocols. He formed, led, and trained the team that designed the commercial QNAP Computer and Network Performance Modeling Tool. He introduced the Flexsim Object Oriented approach for the simulation in manufacturing systems. He published the first work on adaptive control of computer systems, and published seminal papers on the performance optimisation of computer network protocols and on diffusion approximations for network performance. He invented the product form queueing networks with negative customers and triggers known as G-networks.[13] He introduced a new spiked stochastic neural network model known as the random neural network, developed its mathematical solution and learning algorithms, and applied it to both engineering and biological problems. His inventions include the first Voice-Packet Switch SYCOMORE for Thales, the random access fibre-optics local area network XANTHOS, a patented admission control technique for ATM networks, a neural network based anomaly detector for brain magnetic resonance scans, and the Cognitive Packet Network routing protocol to offer quality of service to users [14].[15]

From 1984 to 1986 he served as the Science and Technology Advisor to the French Secretary of State for Universities. He founded the ISCIS (International Symposium on Computer and Information Sciences) series of conferences that since 1986 are held annually in Turkey, the USA and Europe to bring together Turkish computer scientists with their international counterparts.[16] According to the Mathematics Genealogy project, Gelenbe is ranked 12th world-wide among PhD supervisors in the Mathematical Sciences, including Computer Science, having graduated over 86 PhD students.[17] 19 of his former PhD students are women, including a Fellow of the Royal Academy of Engineering of Canada, and the Director General of Higher Education in France. [18]

Latest research interestsEdit

Gelenbe currently [19] works on energy efficient computer systems and self-aware networks, and on network security and on networked auctions. His recent collaborations with biologists include Gene Regulatory Networks and Protein Sequence Alignment.[20]




Selected bibliographyEdit

  • E. Gelenbe "On languages defined by linear probabilistic automata", Information and Control, 16(5):487–501, July 1970.
  • E. Gelenbe "A realizable model for stochastic sequential machines", IEEE Trans. Comput. 20, 199–204 (1971).
  • E. Gelenbe "On approximate computer system models", Journal of the ACM 22(2):261–269 (April 1975).
  • E. Gelenbe and I. Mitrani "Analysis and synthesis of computer systems", Academic Press (June 1980), 239 pp., ISBN 0-12-279350-1, ISBN 978-0-12-279350-9.
  • E. Gelenbe "On the optimum checkpoint interval", Journal of the ACM, 26(2):259–270, April 1979.
  • E. Gelenbe "Product-Form queueing networks with negative and positive customers", Journal of Applied Probability, Vol. 28 (3): 656–663 (Sep. 1991).
  • E. Gelenbe, Mao, Z.H., Li, Y.D. "Function approximation with spiked random networks,", IEEE Trans. on Neural Networks, 10 (1): 3–9, 1999.
  • E. Gelenbe and G. Pujolle "Introduction to Queueing Networks", John Wiley & Sons, Inc. New York City, 1987 and 2000.
  • E. Gelenbe, R. Lent and Z. Xu "Design and performance of a cognitive packet network", Performance Evaluation, 46, (2–3): 155–176, October 2001.
  • E. Gelenbe and Hussain K.F. "Learning in the multiple class random neural network, " IEEE Transactions on Neural Networks, 13(6): 1257–1267, Nov. 2002.
  • E. Gelenbe, Gellman, R. M. Lent, P. Liu and Pu Su "Autonomous smart routing for network QoS", Proc. International Conference on Autonomic Computing: 232–239, ISBN 0-7695-2114-2, 17–18 May 2004.
  • J.-M. Fourneau and E. Gelenbe "Flow equivalence and stochastic equivalence in G-networks", doi:10.1007/s10287-003-0008-z, Computational Management Science, 1 (2): 179–192, July 2004.
  • E. Gelenbe "Steady-state solution of probabilistic gene regulatory networks", Physical Review E, 76(1), 031903 (2007).
  • E. Gelenbe "A Diffusion Model for Packet Travel Time in a Random Multi-Hop Medium", ACM Trans. on Sensor Networks, 3 (2), Article 10, June 2007.
  • E. Gelenbe "Dealing with software viruses: a biological paradigm", Information Security Technical Reports 12: 242–250, Elsevier Science, 2007.
  • E. Gelenbe, G. Sakellari and M. d'Arienzo "Admission of QoS aware users in a smart network", ACM Trans. on Autonomous and Adaptive Systems, 3(1), Idaho TAAS-07-0003, 2008.
  • E. Gelenbe "Network of interacting synthetic molecules in equilibrium" Proc. Royal Society A 464:2219–2228, 2008.
  • E. Gelenbe and I. Mitrani "Analysis and Synthesis of Computer Systems" World Scientific, Imperial College Press, Singapore and London, 2009.
  • E. Gelenbe "Analysis of single and networked auctions", ACM Trans. on Internet Technology, 9 (2), 2009.
  • E. Gelenbe "Steps toward self-aware networks", Communications ACM, 52 (7):66–75, July 2009.
  • A. Berl, E. Gelenbe, M. Di Girolamo, G. Giuliani, H. De Meer, M. Quan Dang, and K. Pentikousis "Energy-efficient cloud computing", Comp. J. 53 (7): 1045–1051, 2010.
  • E. Gelenbe "Search in unknown random environments", Phys. Rev. E 82: 061112, 2010.
  • E. Gelenbe and C. Morfopoulou "A framework for energy aware routing in packet networks", Comp. J., doi:10.1093/comjnl/bxq092, 2011.
  • O. H. Abdelrahman and E. Gelenbe. Time and energy in team-based search. Phys. Rev. E, 87(3):032125, March 2013.


  1. ^ a b Gaster, Adrian. The international authors and writers who's who. International Biographical Centre. ISBN 978-0-900332-45-6.
  2. ^ Barria, Javier A. (2006). Communication networks and computer systems: a tribute to Professor Erol Gelenbe. Imperial College Press. pp. 1–8. ISBN 978-1-86094-659-2.
  3. ^ "ACM SIGMETRICS Life-Time Achievement Award 2008".
  4. ^ "In Memoriam Dennis Gabor Award 2013".
  5. ^ Çaglayan, Professor Ufuk (26 October 2005). "Erol Gelenbe's Career and Contributions". In Yolum, pInar; Güngör, Tunga; Gürgen, Fikret; Özturan, Can (eds.). Computer and Information Sciences - ISCIS 2005. Lecture Notes in Computer Science. 3733. Springer Berlin Heidelberg. pp. 966–970. doi:10.1007/11569596_98. ISBN 978-3-540-29414-6.
  6. ^ "Biographicon: Erol Gelenbe". Archived from the original on 3 October 2011. Retrieved 29 January 2011.
  7. ^ "Departments of ECE and CS - Home".
  8. ^ "Harris Corporation Engineering Center - UCF Campus Map, Orlando FL"..
  9. ^ "Minutes of Senate Meeting" (PDF). Imperial College London. 13 December 2006. Retrieved 20 June 2009.
  10. ^ "Council: Staff Matters" (PDF). Imperial College London. 18 October 2002. Retrieved 20 June 2009.
  11. ^ Missing or empty |title= (help)
  12. ^ "Prof. Sami Erol Gelenbe". IITIS. Retrieved 16 March 2019.
  13. ^ Harrison, Peter (2009). "Turning Back Time – What Impact on Performance?". The Computer Journal. 53 (6): 860–868. CiteSeerX doi:10.1093/comjnl/bxp021.
  14. ^ Missing or empty |title= (help)
  15. ^ Çaglayan, P. U. (2005). "Erol Gelenbe's Career and Contributions". Computer and Information Sciences – ISCIS 2005. Lecture Notes in Computer Science. 3733. pp. 966–970. doi:10.1007/11569596_98. ISBN 978-3-540-29414-6.
  16. ^
  17. ^ "Erol Gelenbe - the Mathematics Genealogy Project".
  18. ^ "Most Students - the Mathematics Genealogy Project".
  19. ^ "Engineering and Technology Magazine". Archived from the original on 12 November 2013. Retrieved 30 March 2013.
  20. ^ "ACM Ubiquity – An Interview with Erol Gelenbe: Practical Theories Make the World Go". Retrieved 30 March 2013.
  21. ^ Gelenbe, Erol. "Décret du 18 avril 2014 portant promotion et nomination" (in French). Journal officiel de la République française.
  22. ^ Gelenbe, Erol. "Grande Ufficiale dell'Ordine della Stella d'Italia (già Stella della solidarietà italiana)" (in Italian). Presidenza della Repubblica. Retrieved 12 November 2013.
  23. ^ Gelenbe, Erol. "Commendatore Ordine al Merito della Repubblica Italiana" (in Italian). Presidenza della Repubblica. Retrieved 12 November 2013.
  24. ^ "Foreign Members – Division IV". Polish Academy of Sciences. Archived from the original on 11 November 2013. Retrieved 12 November 2013.
  25. ^ "HAS General Assembly Elects New Honorary Members". Hungarian Academy of Sciences. Archived from the original on 12 November 2013. Retrieved 12 November 2013.
  26. ^ "Profile: Gelenbe, S. Erol". Hungarian Academy of Sciences. Archived from the original on 20 March 2012. Retrieved 12 November 2013.
  27. ^ "Members of the Science Academy". Bilim Akademisi. Retrieved 12 November 2013.
  28. ^ "Fellows: Erol Gelenbe". Academie des Technologies. Archived from the original on 12 November 2013. Retrieved 12 November 2013.
  29. ^ "Member: Gelenbe, Erol". Academia Europaea. Retrieved 12 November 2013.
  30. ^ "ACM Fellows: Erol Gelenbe". ACM. Retrieved 12 November 2013.
  31. ^ "Fellow Class of 1986". IEEE. Archived from the original on 12 November 2013. Retrieved 12 November 2013.
  32. ^ "Mustafa Prize".
  33. ^ Missing or empty |title= (help)
  34. ^ Chris Edwards (18 January 2011). "Profile: Professor Erol Gelenbe". IET. Archived from the original on 12 November 2013. Retrieved 12 November 2013.
  35. ^ "The IET Achievement Medal Winners 2013". IET. Archived from the original on 12 November 2013. Retrieved 12 November 2013.
  36. ^ "Erol Gelenbe Wins the 2008 SIGMETRICS Achievement Award". ACM SIGMETRICS. Retrieved 12 November 2013.
  37. ^ "Séance académique de remise des insignes de Docteur Honoris Causa" (in French). Universite de Liege. 30 March 2006. Retrieved 12 November 2013.
  38. ^ "DHC2006 : Présentation de M. Erol GELENBE" (in French). Universite de Liege. Retrieved 12 November 2013.
  39. ^ "Prix France Telecom: Laureats de L'Annee 2012" (PDF) (in French). Académie des Sciences. Archived from the original (PDF) on 12 November 2013. Retrieved 12 November 2013.
  40. ^ "Bugüne Kadar Ödül Alanlar: Bilim Ödülü" (in Turkish). ODTÜ Prof.Dr.Mustafa N.PARLAR Eğitim ve Araştırma Vakfı. Retrieved 12 November 2013.
  41. ^ "Holders of the IFIP Silver Core Award (1974–2010)". IFIP. Retrieved 12 November 2013.

External linksEdit

  • Erol Gelenbe's Publications as listed in the DBLP Computer Science Bibliography and his List of Collaborators (including his doctoral students).