If you do not see this message displayed properly, please click here


The Faculty of Informatics is pleased to announce a seminar given by Karine Even Mendoza.



Finding Rare Numerical Stability Errors in Concurrent Computations
Speaker: Karine Even Mendoza
King's College London, UK
Date: Wednesday, May 11, 2016
Place: USI Lugano Campus, room SI-013, Informatics building (Via G. Buffi 13)
Time: 14:30



Stability of a numerical algorithm is an important factor in its analysis, since an error exceeding the bound can lead to disastrous results: for example, the Patriot missile failure in 1991 occurred due to rounding errors and explosion of the Ariane 5 rocket in 1996 was a result of an overflow error. Introduction of concurrency to numerical algorithms results in a significant increase in the number of possible computations of the same result and can lead to instability of previously stable algorithms, since rounding combined with the possibility of different interleaving of threads can result in a larger error than expected for some interleaving. Such errors can be very rare, since the particular combination of rounding can occur in only a very small percentage of interleaving, making the detection of such errors an especially challenging task.

In this talk, I will present a framework for cross-entropy based testing of concurrent numerical programs. The framework combines ideas from cross-entropy based testing, together with abstractions that make these techniques effective for programs with large number of threads. We developed a new tool ACE that implemented our approach.




Karine Even Mendoza: currently a PhD student at King's College London, in the Software Modelling and Applied Logic group under the supervision of Dr Hana Chockler, worked in research at eBay, Netanya, Israel and at IBM Research Labs, Haifa, Israel for several years and obtained her M.Sc. in Computer Science from the Technion(2013) in the field of software verification and testing, software engineering and learning; the results of the M.Sc. thesis were presented at ISSTA 2013.


Host: Prof. Natasha Sharygina


Faculty of Informatics

Faculty of Informatics
Università della Svizzera italiana
Via Giuseppe Buffi 13
CH-6904 Lugano
Tel.: +41 (0)58 666 46 90
Fax: +41 (0)58 666 45 36
Email: decanato.inf@usi.ch
Web: www.inf.usi.ch
Twitter: @USI_INF


Segui USI@EXPO2015 su Twitter Segui USI@EXPO2015 su Facebook Segui USI@EXPO2015 su Linkedin Segui USI@EXPO2015 su YouTube