Dear colleagues,

This is the second announcement of the CWI Scientific Meeting this Friday, February 3.  We'll have four presentations by postdocs, one from each cluster.  Titles and abstracts are given below.  As usual, sandwiches will be provided before the talks.  

We hope to see you at the meeting!

The organizers,
Willem Hundsdorfer and Ronald de Wolf


PROGRAM
Date: Friday, February 3
Time: 13.00 - 14.00
Room: Euler (Z009)

Speakers:
1. Vadim Zaytsev (SEN): The Life Cycle of Grammarware
2. Tobias Marschall (MAC): Efficient Exact Motif Discovery
3. Bart Scheers (INS): Where CWI touches the Sky
4. Erwin Dassen (PNA): Lattices in cryptography


ABSTRACTS

1. Vadim Zaytsev (SEN): The Life Cycle of Grammarware
Abstract: The grammar theory is well-known for being a useful and mature instrument to investigate the structure of software, with grammars being finite definitions of software languages which often turn out to be infinite themselves. It is commonly assumed that this theory has solved all its problems years ago. However, many issues arise in practice, and the domain and theory of grammarware engineering are still underdeveloped. In this talk, I will elaborate on such unresolved issues and provide examples from recent research.

2. Tobias Marschall (MAC): Efficient Exact Motif Discovery
Abstract: The motif discovery problem consists of uncovering exceptional patterns (called motifs) in sets of sequences. It arises in molecular biology
when searching for yet unknown functional sites in DNA sequences. We present a motif discovery algorithm that (1) is exact, that means it returns a motif with optimal score, (2) can use the statistical significance with respect to complex background models as a scoring function, (3) takes into account the effects of self-overlaps of motif instances, and (4) is efficient enough to be useful in large-scale applications.  An Open Source implementation of the algorithm is publicly available (http://mosdi.googlecode.com).

3. Bart Scheers (INS): Where CWI touches the Sky
Abstract: Next generation astronomical observatories are designed for high-speed all-sky surveys, searching for rapid transient and variable sources,
cataloguing repeated measurements of the millions of sources.  Consequential, these facilities will produce tens of terabytes per day. High-cadence data rates of tens of gigabits per second are not exceptional. LOFAR, the Low Frequency Array, is a radio telescope that is designed according to these principles. It is an excellent example where the fields of astronomy, engineering, computer science and informatics overlap and cross each other. In fact, the next-generation telescopes cannot succeed without one of the disciplines.
CWI, in particular INS, enters the interdisciplinary "field" with its expertise of a fast column-store that can data mine the hundreds of TBs. In this talk, I will give an overview of the telescope, its scientific goals, and what makes the sky a bit more CWI-ish.

4. Erwin Dassen (PNA): Lattices in cryptography
Abstract: The aim of the talk is to introduce, on a very high level, lattices (groups, not ordered sets) and how they are currently used in cryptography. We explain the "hard" lattice problems used as base for the security of those cryptosystems and what is meant with a fully homomorphic encryption scheme.