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Many Facets of Computation: An Insight in Current Trends

15 december 2017
Kamerlingh Onnes Building
Steenschuur 25
2311 ES Leiden
Lorentz-zaal (room A144)

Symposium 'FACETS' in honour of Prof. Rozenberg

A symposium celebrating the lifetime achievements of Grzegorz Rozenberg on the occasion of his 75th birthday.

The symposium 'Many Facets of Computation: An Insight in Current Trends' is organised by the Leiden Institute of Advanced Computer Science (LIACS), in collaboration with the Institute of Biology Leiden (IBL), the Faculty of Science, and Leiden University.

It takes place in the beautiful Lorentz-zaal of the Kamerlingh Onnes Building in the old city centre of Leiden. The program consists of scientific contributions discussing some current trends in Informatics and Natural Computing. The talks are followed by a reception which provides an opportunity to meet Grzegorz Rozenberg and prominent researchers from LIACS and IBL in an informal setting.


Please send an email to Marloes van der Nat if you plan to attend this meeting and/or the reception.

Organisation and information

For more information you may contact one of the organisers, Jetty Kleijn and Marloes van der Nat.


Starting time Activity
13:00 Lorentz-zaal open for walk-in
13:15 Opening Symposium by Jetty Kleijn (LIACS)
Session 1 Chair: Aske Plaat (Scientific Director LIACS)
13:30 Thomas Bäck (Natural Computing, LIACS)
'The Magic of Evolutionary Computation'

In a search space of a size beyond our imagination, organic evolution has created life as we know it today. What seems like magic, is a search process of amazing efficiency. Over the past 60 years, we have gained a remarkable understanding of the underlying principles and how they can be used to solve nonlinear search and optimization problems in a variety of different fields. In this presentation, I will discuss some examples from different areas, illustrating how evolutionary computation can be used to create innovations - ranging from turbine blades to drug design. In addition to those practical examples, I will also present a few fundamental principles of evolutionary computation, such as the tradeoff between success probability and step size. The talk will be concluded with a tiny piece of magic, created by evolutionary computation.
13:55 Christiaan V. Henkel (IBL)
'Computing nature'

Computational approaches offer excellent prospects for understanding and explaining biological complexity. Traditionally, algorithmic perspectives on biology are hindered by a lack of rigorous problem definitions (e.g. how to formalize the question 'what is life?'), as well as by a serious lack of 'input data'. The latter issue, at least, is quickly disappearing with the advent of omics technologies. In my talk, I will explore a few facets of biological complexity emerging from recent developments in genome sequencing technology and bioinformatics.
14:20  Robert Brijder (Hasselt University, B; formerly LIACS)
'From the functioning of the living cell to a model of computation'

Reaction systems, introduced by Andrzej Ehrenfeucht and Grzegorz Rozenberg, provide a formal framework to study the behavior of biochemical processes in living cells. In a reaction system, biochemical reactions are formalized in terms of facilitation and inhibition. A reaction system is an open system that evolves by interacting with its environment. We introduce reaction systems, highlight some research themes, and compare them with some models of computation.
14:45 Coffee break
Session 2 Chair: Herman Spaink (Scientific Director IBL)
15:15 Holger H. Hoos (Machine Learning, LIACS)
'The art and science of advanced computation'

In the barely 60 years of its existence as a discipline and profession, computing science has transformed the way we work, live and interact. While amazing and sustained progress in computing devices has played a key role in ushering in this age of computation, an even larger role can be ascribed to the algorithms running on these machines and the computational thinking giving rise to both. In this talk, I will contrast a commonly held narrow view of computation with a richer, more comprehensive notion - a view that is better suited to position computing science as a discipline that inspires, connects and unifies. I will explain how the machine learning revolution - a transformational change currently underway within computing science and its many applications - can be understood in the context of a broader phenomenon of advanced computation that has the potential to radically change our industries, societies and culture. Finally, I will argue that much of advanced computation is based on practices that resemble a craft or art rather than a science, and that a more scientific approach will not only unlock the true potential of advanced computation, but also enable its safe and responsible use.
15:40 Fons J. Verbeek (LIACS, IBL)
'Stealth in the Self - modelling the immune response to infection with a Petri net'

The essence of defense against intruders in a system is to be able to distinguish the self from the non-self. Living systems have developed mechanisms to respond to the non-self and at the same time intruders have found ways to prevent being destroyed by such response. Understanding these complex hide-and-seek mechanisms requires deeper insight in strategies that are employed by a host and an intruder. Such can be very well modelled by a Petri net. With a Petri net for infection available, computer simulations can be done. This can explain some host-intruder behaviors in biology while at the same time an emergent property of such net is that it stands as model for infections of computer systems. In this manner the Petri Net is a muse to the constant reciprocal inspiration between computer science and biology.
16:05 Joost N. Kok (Leiden Centre of Data Science, LIACS)
'Winning with Data Science'

The Leiden Centre of Data Science (LCDS) started two years ago as a network of researchers. The university-wide LCDS Data Science research program has started in 2017. We will provide an overview of this program which connects Data Science to other domains. One of these domains is Sports, Vitality and Movement. We will present two showcases of Sportinnovator.nl that were carried out at LIACS: the analysis of the data of six million runners and the quest to find the golden standard in Soccer at the WEURO 2017 through Data Science.
16:30 Closing and Reception


About Grzegorz Rozenberg, the guru of Natural Computing

Grzegorz Rozenberg is a world famous researcher in the areas of Theoretical Computer Science and Natural Computing. He has played a central role in the development of theoretical computer science in Europe and defined the field of Natural Computing, giving it its name and defining its scope - he is often called the guru of Natural Computing. His research interests are broad and often of an interdisciplinary nature. He has published over 500 papers, 6 books, and is a (co-)editor of more than 100 books. He has also served the international computer science community in many different capacities, from memberships of program committees and editorial boards to being a driving force as chair of the steering committee for various  developing new research fields. He was the longest serving President of the European Association for Theoretical Computer Science (EATCS).

International recognition as scientist

The achievements of Rozenberg are well-recognised by the international scientific community. He is the holder of six Honorary Doctorates, from: the University of Turku (Finland), the Technical University of Berlin (Germany), the University of Bologna (Italy), the Swedish Åbo Akademi University in Turku (Finland), the Warsaw University of Technology (Poland), and the University of Bucharest (Romania).  A number of books and special issues of renowned journals were dedicated to him. He received numerous international scientific prizes. Also, the prestigious award granted annually by the International Society for Nanoscale Science, Computation, and Engineering, is named after him.

Founding father Computer Science in Leiden

For LIACS, Rozenberg is one of its founding fathers. With this symposium LIACS celebrates not only his outstanding scientific achievements, but also acknowledges his crucial contributions towards the establishment of computer science as an independent scientific discipline in Leiden.

Since 1979, Rozenberg has been a full professor at Leiden University. Shortly after his appointment, Leiden University was among the first universities in the Netherlands that created a Computer Science (Informatica) curriculum and a few years later also a Department of Computer Science (the predecessor of the current LIACS). Rozenberg was involved in both and also of paramount importance in their subsequent scientific development. He set up the Theoretical Computer Science research group which became internationally well-known. Furthermore, also at the national level, he played an important role in the emergence of the field of Informatica, for instance as one of the founders of the Dutch Association for Theoretical Computer Science (NVTI, Nederlandse Vereniging voor Theoretische Informatica).

Leiden Centre of Natural Computing

His interest in natural sciences led to investigations of computations as they take place in nature. This gave rise to interdisciplinary cooperations with biologists abroad and at home. Together with colleagues in Leiden, from LIACS and IBL, he founded the Leiden Centre of Natural Computing and was its first director.

After his formal retirement in 2012, he is still very active as a researcher and involved in numerous interdisciplinary and international collaborations. He frequently travels with lectures to share his knowledge and innovative insights.

Celebrating the age of 75

This year, Rozenberg has reached the age of 75.  To celebrate this occasion, the University of Turku, the Swedish Åbo Akademi in Turku, and the well-known conference 'Computability in Europe' organised the international symposium 'Magic in Science' which took place in June 2017 in Turku, Finland. The name of the symposium was inspired by the fact that Rozenberg is also a performing magician (furthermore, he is an expert in the paintings of Hieronymus Bosch). The scientific program of the symposium covered a broad range of topics, reflecting Rozenberg's research interests. Also an impressive Liber Amicorum was published on this occasion.

Like 'Magic in Science', also FACETS celebrates the 75th birthday of Rozenberg. In particular, it acknowledges the tremendous role that he has played in the development of Computer Science in Leiden and in the Netherlands. Discussing various exciting facets of computation, its program illustrates the enormous progress that Informatica has made since the pioneering years of Grzegorz Rozenberg.