Erol Gelenbe


Sami Erol Gelenbe is a Turkish-French computer scientist, electronic engineer and applied mathematician who is a Professor in the Institute of Theoretical and Applied Informatics of the Polish Academy of Sciences, Visiting Professor at Imperial College, and also affiliated with the I3S Laboratory of the University of Cote d'Azur. Previously he was a Chaired professor at University of Liege, University Paris-Sud, University Paris Descartes, Duke University, the University of Central Florida and 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 awards include the Grand Prix France Telecom of the French Aademy of Sciences, ACM SIGMETRICS Life-Time Achievement Award, the Oliver Lodge Medal of the UK's Institution of Engineering and Technology, and the "In Memoriam Dennis Gabor Award" of the Hungarian Academy of Sciences.

Biography

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, 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". 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.
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, 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 and created the Harris Corporation Engineering Centre
In 2003, Gelenbe was offered a Chair at Imperial College London as the Dennis Gabor Professor in Computer and Communication Networks and Head of Intelligent Systems and Networks, from which he retired in 2019. He is a Professor in the Institute of Theoretical and Applied Informatics of the Polish Academy of Sciences.

Notable contributions

Gelenbe invented the Random neural network model and its polynomial-time learning algorithm. He invented the eponymous G-network, a mathematical model of the performance of distributed systems and networks with complex node to node interactions, 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 leading to a widely used commercial product. He published the first work on adaptive control of computer systems to optimise time-sharing 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. 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.
From 1984 to 1986 he served as the Science and Technology Advisor to the French Secretary of State for Universities. He founded the ISCIS 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.
According to the Mathematics Genealogy project, Gelenbe is ranked 9th world-wide among PhD supervisors in the Mathematical Sciences, including Computer Science, having graduated some 90 PhD students. 24 of his former PhD students are women, including a Fellow of the Royal Academy of Engineering of Canada, and the former Director General of Higher Education in France.

Latest research interests

Gelenbe currently 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.

Honours