Fall Days @ ICT.OPEN 2012

World Trace Center, Rotterdam,
October 22-23, 2012

The traditional IPA Fall Days are this year part of the ICT.OPEN event. This event aims to bring together researchers coming from diverse fields of ICT. The event is organised by NWO, STW and the three Dutch Research Schools ASCI, IPA and SIKS.


Detailed information regarding the programme can be obtained through the ICT.OPEN website in the coming days. Within the larger programme, IPA has a track on Programming and Algorithmics. The tentative programme for this track is as follows (titles and abstracts will be provided soon):


10:00-10:15 Plenary opening
10:15-11:00 Plenary Keynote: Wendy Hall
11:05-11:35 Coffee break
11:45-12:35 Johan Jeuring, OU and UU,
Generic programming: flexible and safe software
12:35-13:00 José Pedro Magalhães, University of Oxford, 
Functional Modelling of Musical Harmony
Music theory has been essential in composing and performing music for centuries. Within Western tonal music, from the early Baroque on to modern-day jazz and pop music, the function of chords within a chord sequence can be explained by harmony theory. Although Western tonal harmony theory is a thoroughly studied area, formalising this theory is a hard problem. We present a formalisation of the rules of tonal harmony as a Haskell (generalized) algebraic datatype. Given a sequence of chord labels, the harmonic function of a chord in its tonal context is automatically derived. For this, we use several advanced functional programming techniques, such as type-level computations, datatype-generic programming, and error-correcting parsers. As a detailed example, we show how our model can be used to improve content-based retrieval of jazz songs.
13:00-14:00 Lunch
14:00-15:00 Poster Session
15:00-15:50 Jan Friso Groote, TU/e,
Model driven software design: up to 10 fold quality improvement
Philips Healthcare has introduced model driven software design for their embedded apparatuses. They use ASD developed by the Verum company (located in Waalre) to design models of the software to be constructed, to verify the correctness, and to generate code. This provided an unique opportunity to compare product development in a traditional way with a formal approach. The results show a definitive improvement of quality (there is a factor up to three less time required and up to a factor 10 less problem reports).
15:50-16:15 Mark Timmer, UT,
Efficient Modelling and Generation of Markov Automata
This presentation introduces a framework for the efficient modelling and generation of Markov automata. It consists of (1) the data-rich process-algebraic language MAPA, allowing concise modelling of systems with nondeterminism, probability and Markovian timing; (2) a restricted form of the language, the MLPPE, enabling easy state space generation and parallel composition; and (3) several syntactic reduction techniques on the MLPPE format, for generating equivalent but smaller models.

Technically, the framework relies on an encoding of MAPA into the existing prCRL language for probabilistic automata. First, we identify a class of transformations on prCRL that can be lifted to the Markovian realm using our encoding. Then, we employ this result to reuse prCRL’s linearisation procedure to transform any MAPA specification to an equivalent MLPPE, and to lift three prCRL reduction techniques to MAPA. Additionally, we define two novel reduction techniques for MLPPEs. All our techniques treat data as well as Markovian and interactive behaviour in a fully symbolic manner, working on specifications instead of models and thus reducing state spaces prior to their construction. The framework has been implemented in our tool SCOOP, and a case study on polling systems and mutual exclusion protocols shows its practical applicability.

16:15-16:45 Coffee break
16:45-17:35 Han la Poutré, CWI and UU,
ICT for Smart Energy Systems
Our future energy system will include an increasing amount of durable energy generators, like solar cells and wind turbines. In addition, new devices with heavy energy demands will further emerge, like e-vehicles and heat pumps. These developments call for new types and approaches for our energy systems, towards the so-called Smart Energy Systems (SES). In SES, ICT will play an important role. We will present developments, results, and challenges for computer science in the field of SES.
17:35-18:00 Nicolas Hëning, CWI,
Market mechanisms for flexible scheduling of electricity
Balancing supply and demand is a crucial function of electricity markets of tomorrow. We need to enable actors to offer reserves and encourage them to be flexible. I study this problem by agent-based simulation. In particular, I propose a novel two-sided auction to bundle bids to the ahead market and the balancing market and I study how retail contracts using a dynamic pricing regime affect flexible and non-flexible energy consumers.
18:05-18:50 Plenary Keynote: Kees Schouhamer Immink
19:00-22:00 Dinner + Social Programme


10:00-10:50 Walter Kosters, UL, Data Mining
Data mining aims at the discovery of interesting patterns. It is in some sense complementary to statistics. Data files are usually very large, and range from seemingly random to extremely ordered. Current research deals with graphs instead of just sequences, uses summaries, and tries to incorporate time aspects. We will discuss general approaches (often originating within artificial intelligence, or rather machine learning), some case studies, and touch upon privacy issues.
10:50-11:15 Frank Takes, UL, Computing the Diameter of Large Graphs
Within the field of graph mining, a typical graph can have millions of nodes and possibly billions of edges, which makes computing certain properties, such as the graph’s diameter, very complex. However, many real-world graphs have a somewhat identical structure. For example, social networks, web graphs, routing networks and biological networks all adhere to the small world property. We present an exact algorithm for computing the diameter (longest shortest path length) of large small world graphs, which significantly improves upon the computation time of the traditional algorithm.
11:15-11:45 Coffee break
11:45-12:35 Jan Rutten, CWI and RU,
The method of coalgebra - an overview
Since the early nineties, coalgebra has become an active area of research in which one tries to understand all kinds of infinite data types, automata, transition systems and dynamical systems from a unifying perspective. The focus of coalgebra is on observable behaviour and one uses coinduction as a central methodology, both for behavioural specifications and to prove behavioural equivalences. These days, one uses coalgebraic techniques in a wide variety of areas, ranging from automata theory to software engineering to ecology. In this talk, we shall illustrate the coalgebraic approach by discussing a number examples, including streams, automata and circuits.
12:35-13:00 Joost Winter, CWI,
Coalgebra and behavioural differential equations
The framework of behavioural differential equations is a further development of Janusz Brzozowski’s insight that we can conveniently perform computations on regular expressions using a calculus of derivatives. We present a coalgebraic framework for systems of such equations.

Using these systems of behavioural differential equations, we are able to give an easy and elegant characterization of regular and context-free languages; furthermore we will use systems of b.d.e.’s to characterize streams, and note that here it is possible to generalize the notions of regularity and context-freeness.

13:00-14:00 Lunch
14:00-15:15 Soft Skills sessions
14:50-15:20 Coffee break
15:20-16:05 Plenary Keynote: Nico Baken
16:05-16:50 Plenary Keynote: Hugo de Man
16:50- Drinks


Registration proceeds via the ICT.OPEN website. The registration procedure is taken care of by NWO and STW, and bypasses IPA’s office. Because of this, upon registering for the event, an invoice will be sent to you, which you (or your research group) will have to pay. There are several hotels from which you can choose.

If you are an IPA PhD student, IPA will reimburse the registration costs for the event, and at most 62,50 euro of your hotel costs, regardless of the hotel. The following conditions apply:

  • You are an IPA student at the time of the event.
  • Students will not be reimbursed for no-show. In case of timely cancellation, IPA will reimburse the costs (if any) of cancellation.

Note that reimbursement will take place after the event. For this, we need a digital or hard-copy proof of payment of the invoice, together with the bank account details (and the appropriate details for the research group in case the research group paid the invoice). These details must be sent to the IPA office, or via email, to ipa ‘at’ tue.nl before the end of November 2012.