last updated on 09 November 2018

Björn Rüffer/News Archive

News archive

Earlier this year, I have joined the editorial board of the IFAC journal Automatica (published by Elsevier) as an associate editor. IFAC - International Federation of Automatic Control

Already since 2010, I am serving as associate editor for Systems & Control Letters (SCL), another journal published by Elsevier. Since the commencement of my role, I have handled more than 120 submissions for this journal.

Both journals are flagship outlets in the systems and control theory community and serve mathematicians and engineers alike. They have the highest (A* and, respectively, A) ranks in the former ERA ranking system, which is to say they are among the best journals in their field, and that is, of course, owed to their rigorous referee processes and quality submissions by authors.

It makes me very proud to continue to be part of this important quality control process for science, which would never be possible without the countless hours invested by the expert referees who assess novelty, significance, and correctness of every manuscript, and who always remain anonymous, rarely get public acknowledgement, and, like associate editors, do not get paid for their indispensable contribution. To them I say: Thank you, thank you, thank you!

As part of the CARMA special semester on Mathematical Thinking, James Juniper, Heath Jones, our friends from CARMA, and I are organising a workshop on the teaching of mathematical concepts using diagrammatic reasoning in higher education, to be held

University of Newcastle NeW Space Building

November 9-11, 2018

in the scenic NeW Space building, Newcastle. With the help of several high profile speakers, we want to investigate the potential for diagrammatic reasoning to be used to enhance the teaching of mathematics and abstract concepts across a range of disciplines (of business and economics, physics, engineering, and computer science) at the University of Newcastle, especially with a view to enhance the learning of diverse student cohorts.

For further information and registration, please visit the workshop website.

To create presentations or lectures with mathematical content on an iPad Pro the app Notability is my personal favourite. I have created some templates that have the right page format so that one page fills the entire visible screen/writing area in the app.

These include templates with

The templates have been generated with LaTeX/tikz and the source code is available on GitHub.

It took two rounds of close votes before Australia’s bid to host IFAC’s Symposium on Nonlinear Control Systems (NOLCOS) 2022 in Newcastle was successful against three strong bids from China, Korea, and the UK during the meeting of the technical committee on nonlinear systems at the 2017 IEEE Conference on Decision and Control. IFAC, that is the International Federation of Automatic Control, was founded in September 1957. With the first NOLCOS held in Capri, Italy in 1988, this is the first time the triennial conference is hosted in Oceania.

Chris presenting the Newcastle proposal

The Australian bid was a concerted effort by colleagues of several leading Australian universities including Australian National University (Ian Petersen, Robert Mahony, Jochen Trumpf), Macquarie University (Vladimir Gaitsgory), Queensland University of Technology (Tristan Perez, Alejandro Donaire) Royal Melbourne Institute of Technology (Vera Roshchina), University of Melbourne (Iven Mareels, Dragan Nešić, Peter Dower), University of New South Wales (Valery Ugrinovskii), University of Newcastle (Chris Kellett, Björn Rüffer, Steve Weller, Adrian Wills), University of South Australia (Regina Burachik), and University of Sydney (Ian Manchester).

The conference organising committee consists of:

  • Chris Kellett (General Chair)
  • Rob Mahony (National Program Chair)
  • Lorenzo Marconi (International Program Chair)
  • Tristan Perez (Industrial Chair)
  • Jochen Trumpf (Web and Publications Chair)
  • Björn Rüffer (Local Arrangements Chair)

We look forward to welcome many colleagues from the nonlinear systems and control community to Newcastle, Australia, in 2022!

With the help of CARMA, Chris Kellett and I are hosting a workshop on Mathematical Systems Theory and Applications in early December. A detailed program can be found here.


The 6th International Conference on Positive Systems (POSTA2018) will take place at Hangzhou Dianzi University, Hangzhou, China from August 25th to 27th, 2018. As with previous conference, the scope of POSTA2018 will cover a wide range of topics from theory to applications of positive systems. Talks presenting new results as well as surveying recent work are welcome. The POSTA proceedings will be published in the Springer LNCIS Series after the conference. Previous editions of the conference were held in Rome, Italy (2003), Grenoble, France (2006), Valencia, Spain (2009), Maynooth, Ireland (2012) and Rome, Italy (2016).

Conference topics include, but are not limited to, Positive systems with delay; Hybrid positive systems; Stochastic realization theory and positive systems; Dynamic analysis and control synthesis of positive distributed parameter systems; Monotone dynamical systems theory and applications in mathematical biology, game theory, and other fields; Recent mathematical developments for networked systems in biology, chemistry and social sciences; Linear and nonlinear positive operators and their applications; Biological systems with positive variables and positive controls; Boolean network; Smart cities and positivity; Iterated function systems; Dimensioning problems for collaborative systems; Matrix analysis and its applications in nonnegative dynamic processes and/or positive multidimensional systems.

Conferences dates
  • Submission Open: October 1, 2017
  • Submission Deadline: March 10, 2018
  • Paper Decision Notification: April 25, 2018
  • Registration Open: April 25, 2018
  • Accepted Submission Open: April 30, 2018
  • Registration Deadline: June 1, 2018
  • Accepted Submission Deadline: July 20, 2018
  • Conference: 25–27 August 2018

Please refer to the conference website for further details.

Gérard Scorletti, Paolo Massioni, and Vincent Andrieu are organising a workshop on incremental methods in control, to be held in Lyon, France in early July. I will speak about the relationships among Contraction analysis, Extreme stability, and Convergent Dynamcis.

Positive Systems: Theory and Applications (POSTA 2016) Rome, Italy, September 14-16, 2016

The proceedings of the 5th International Symposium on Positive Systems (POSTA), which was held at Università Campus Bio-Medico di Roma, Italy, in September 2016, is now available.

I am contributing a chapter on Nonlinear left and right eigenvectors for max-preserving maps, which are useful, e.g., in the stability analysis of networks of systems. There’s also an arXiv preprint of the chapter available. The entire book can be found here.


Conferences dates
  • Early-bird registration closes: 24 May, 2017
  • Abstract submission closes: 4 June, 2017
  • Registration closes: 2 July, 2017
  • Conference: 24-28 July, 2017

Please refer to the conference website for further details.

Photo of the people involved in establishing this agreement. A new student exchange program was established when Dr Arnim Heinemann, Head of International Office at the University of Bayreuth in Germany, signed a formal agreement during a visit to UON on January 27th. The program will allow UON students who have completed their Honours year to study at the University of Bayreuth for one year and receive recognition for the first year of their Master studies, and subsequently, have the chance to obtain a Master of Science in one additional year. In return, German students can study at UON during their fourth year to obtain an Honours degree, and upon returning home, their achievements during their Honours studies will be acknowledged as part of their Master studies.

The program concept was instigated by Professor Lars Grüne, Chair of Applied Mathematics at Bayreuth University, who was a visiting fellow at UON in 2015 and myself.

Mathematics honours students at UON who are interested in participating in this exchange should contact me for details.


Dr Andrew Kepert and I will showcase some of the tools we have developed and use to manage assessment items in large-enrolment courses in the CARMA Teaching and Learning seminar. More details are here.


UON and CARMA will host the 12th International Conference on Fixed Point Theory and Its Applications in July 2017.

This conference will bring together leading experts and researchers in fixed point theory. It aims to assess new developments, ideas and methods in this important and dynamic field. A special emphasis will be put on applications in related areas, as well as other sciences, such as the natural sciences, medicine, economics and engineering.

A great opportunity for visiting Newcastle! Hope to see you there!

Picture of Collosseum in Rome, Italy; supplied by POSTA2016.ORG

POSTA will be held in Rome, Italy, in September 2016. Deadlines for submissions of contributed papers and session proposals are in April 2016. More details are to be found at

Sydney skyline

The NSW/ACT chapter of ANZIAM is holding its annual meeting at the UON Sydney campus. More details at

The current issue of DCDS-B contains a special section on computational methods for Lyapunov functions. Quoting from the editorial:

Lyapunov functions, introduced by Lyapunov more than 100 years ago, are to this day one of the most important tools in the stability analysis of dynamical systems. They are functions which decrease along solution trajectories of systems, and they can be used to show stability of an invariant set, such as an equilibrium, as well as to determine its basin of attraction. Lyapunov functions have been considered for a variety of dynamical systems, such as continuous-times, discrete-time, linear, non-linear, non-smooth, switched, etc. Lyapunov functions are used and studied in different communities, such as Mathematics, Informatics and Engineering, often using different notations and methods.

Since Lyapunov functions provide insight into the dynamics, it is an important question how to find them. A first answer is given by so-called converse theorems, which ensure the existence of a certain type of Lyapunov function given a certain type of stability. These theorems, however, are not constructive in nature as they usually use the solution trajectories to construct the Lyapunov function. This means, that they cannot be used directly to find an explicit Lyapunov function for most concrete examples. Therefore, computational methods have been derived to construct Lyapunov functions, using as diverse methods as optimization, Linear Matrix Inequalities, numerical solutions to Partial Differential Equations using collocation or other methods, graph theoretic methods, algebraic methods, and others.

This special issue brings together all these aspects: starting with two surveys on computational methods and converse theorems for Lyapunov functions and then continuing with six research articles which cover a wide range of current research for the construction of Lyapunov functions. The contributions also bring experts from different disciplines together in one volume

The publisher told me that this newly published issue’s full texts remain accessible to the public for a couple of weeks. Among other contributions, this special section contains some very nice review articles that could serve as a good starting point for anyone interested in the subject. More can be found here.

Update 04/10/2015 Free full text access is no longer available, unfortunately.

MTNS 2016 banner The 22nd MTNS will be held in Minneapolis at the campus of the University of Minnesota.

See for details, as they are being announced.

(Youtube video at

In this video I explain my research area in very broad terms.

My first MTNS was in Kyoto, Japan, in 2006. It was my first conference outside Europe, a great experience, and to some extent it was one of the reasons why I decided to stay in academia: Part of the job description as a researcher is that you travel to nice and interesting places. Kyoto certainly ticks all the boxes.

But the symposium itself is also special, and I’m tempted to say that it is my favorite conference. It is not small, but unlike many other bigger conferences that I have attended, MTNS is organized by an international steering committee of volunteers without the support of a major society behind it, and it takes place only every two to three years.

Now, the next turn is on Groningen, Netherlands. A lively place in the heart of Europe. The call for papers is available on the website of MTNS 2014. The submission deadline for contributed papers is November 25, 2013. Looking forward to see you there!

IEEE Senior membership plaque I have been elevated to senior membership level with the IEEE.

There is an upcoming workshop on Lyapunov functions to be held at Reykjavík University.

26 November 2012

IET Premium Award

IET Premium Award certificate The paper Belief propagation as a dynamical system: the linear case and open problems, BS Rüffer, CM Kellett, PM Dower, SR Weller, IET Control Theory & Applications, July 2010, 4 (7), 1188—1200 has been recognised as the best research paper published during the last two years in IET Control Theory & Applications.

The workshop will take place in Louvain-La-Neuve, Belgium, on October 10, 2012.

Refer to the program for details. Registration is mandatory but free, and I am happy to provide details upon request.

The MCSS special issue on Robust stability and control of large-scale nonlinear systems is available online now. See the Springer website.

MCSS special issue on Robust stability and control of large-scale nonlinear systems to appear soon

We were able to solicit a number of outstanding papers on subjects ranging from (numerical) stability analysis, necessary conditions for stability, quantized control design, over stabilization of partial differential equations and switched large-scale systems to desynchronization of coupled oszillators. This special issue will be a double issue and is going to appear rather soon.

Some of the articles are available online, already.

I am serving on the technical programme committees of the following international conferences:

  • MTNS 2012

    The 20th International Symposium on Mathematical Theory of Networks and Systems will be held at the University of Melbourne, Australia, July 9—13, 2012.

  • POSTA 2012

    The 4th International Symposium on Positive Systems, to be held at the Hamilton Institute, National University of Ireland, Maynooth from the 2nd to the 4th of September 2012.

The submission deadline for contributions to the Special issue on Robust stability and control of large-scale nonlinear systems with the journal Mathematics of Control, Signals, and Systems (MCSS) has been extended to May 9, 2011.

I have recently joined the editorial board of the Elsevier journal Systems & Control Letters as an associated editor.

Zhong-Ping Jiang, Sergey Dashkovskiy and I are soliciting papers for a special issue with the journal Mathematics of Control, Signals, and Systems (MCSS). The call for papers is available in HTML and PDF formats. The submission deadline is May 1, 2011.