Liquid: RDF meandering in FluidDB

Meandre (NCSA pushed data-intensive computing infrastructure) relies on RDF to describe components, flows, locations and repositories. RDF has become the central piece that makes possible Meandre’s flexibility and reusability. However, one piece still remains largely sketchy and still has no clear optimal solution: How can we facilitate to anybody sharing, publishing and annotating flows, components, locations and repositories? More importantly, how can that be done in the cloud in an open-ended fashion and allow anybody to annotate and comment on each of the afore mentioned pieces?...

Aug 25, 2009 · 7 min · 1352 words · Xavier Llorà

Squeezing for cycles

Sometimes thinking a bit helps to rush decisions that may lead to weird places. Today I was going over a simple genetic algorithm for numeric optimization written in C. The code is nothing special, tournament selection without replacement, SBX crossover operator, and polynomial mutation. To the point, I was running a simple OneMax-like problem (in this case, minimize the value of the sum of all the genes), and I was quite surprised the guy was taking so long for....

Apr 2, 2009 · 6 min · 1137 words · Xavier Llorà

Free online survey service

Pier Luca Lanzi sent an email the other about help SigEvolution newsletter by taking an on-line survey. The survey was host at SurveyMonkey.com. I had never run into this guys before, but after digging a bit, the idea is pretty sweet. Need to run a survey? Just register to their site, create the survey, graph the link to it, and spread it around. Also, they allow you to upload surveys to their servers....

Nov 14, 2008 · 1 min · 98 words · Xavier Llorà

GALE is back!

Yes, with the new update of the website GALE was unreachable for a while. Here it is the original code again. Please, take a few minutes to read this post. Hope you find it useful. Enjoy :D GALE? GALE (Genetic and Artificial Life Environment) is fine-grained parallel genetic algorithm for data mining. Its main contributions are simplicity and its knowledge-independent model. The simplicity of GALE relies in its fine-grained parallelism based on spreading the population (feasible solutions to the classification task) over a 2D grid....

May 10, 2006 · 3 min · 445 words · Xavier Llorà

Metadata stores and D2K

Today I gave a presentation for the ALG group in NCSA about metadata stores and how they can be used in D2K. The presentation has two parts. The first one covers and introduction to metadata in general with some examples. The second one, is about how to wrap a metadata store (Kowari, see the previous post here) and make it accessible in D2K. You can find the slides here.

Apr 21, 2006 · 1 min · 69 words · Xavier Llorà