Research

by Xavier Llorà, Noriko Imafuji Yasui, Michael Welge, David E. Goldberg (in press, 2007). To apper in the Proceedings of the Digital Humanities 2007 Conference.Also as IlliGAL TR No. 2006023. Link to the PDF. Abstract Blogging has become a new and disruptive communication medium. Blogs have changed the way people and organizations express, interact, and—quite unforeseen—exercise influence. The digital nature of the blog media provides access to an always-expanding corpus of information. It would take more than a lifetime to read all the available blogs necessary to answer questions such as what were the more relevant plots suggested or what key concepts were managed by bloggers in their ideas. However, human-centered analysis and visualization techniques may help users navigate such enormous corpus. This paper presents human-centered analysis and visualization techniques for supporting innovation and creativity can help to identify relevant post portions and to visualize concept relations in the blogosphere. ...

September 21 I was invited to give a talk at the Computer Science Department at UIUC. During the talk “Combating User Fatigue and Contradictions in Subjective-based Optimization Schemes” I reviewed some of the research I have been involved about active interactive genetic algorithms. The PDF of the presentation can be downloaded here. I also gave the same presentation to some of the members of the ASAP research group at the University of Nottingham. Natalio Krasnogor invited me for a visit. The main topic was latest advances on Pittsburgh LCS (Jaume Bacardit is working there on protein folding problems using Pitt-style LCS). I really enjoyed interact with people there—lots of challenges and interesting discussions. Oh, I almost forgot, the three days I was in Nottingham I saw the sun most of the day :). ...

Recently I have been working on a data-mining problem that requires supervised learning. The problem is not supposed to be big, just a few hundreds of features. The interesting issue is the number of records, around half a million or more. Most of the implementations of supervised learning algorithms available on the web are not designed with such a volume of data. Scalability of the algorithms becomes a clear issue when dealing such a volume of data. For instance, algorithms that scale as n^3 with respect to the data may become prohibitively costly for any feasible approach. Also, algorithms that require global processing, defeating efficient parallelization may not be an option either. For such reasons, I started working last fall on efficient implementations of GBML algorithms focusing on (1) efficient implementations hacking the available hardware, (2) minimizing memory food prints required, and (3) massively exploiting the inherent parallelism of such methods. A few initial steps can be found here and here. ...

by Cecilia Ovesdotter Alm and Xavier Llorà (2006). Proceedings of the Ninth International Conference on Spoken Language Processing (INTERSPEECH 2006), paper 1741. Also as IlliGAL TR No 2006018. Link to the PDF. Abstract Emotion is expressed by prosodic cues, and this study uses the active interactive Genetic Algorithm to search a wide space for sad and angry parameters of intensity, F0, and duration in perceptual resynthesis experiments with users. This method avoids large recorded databases and is flexible for exploring prosodic emotion parameters. Solutions from multiple runs are analyzed graphically and statistically. Average results indicate parameter evolution by emotion, and appear best forsad speech. Solutions are quite successfully classified by CART, with duration as main predictor. ...

Vacations were over quite a while ago, but things kept piling on my desk. Finally I succeeded clearing some big chunks of matters out of it. Enough that I could go to the Design Theory and Methodology (DTM 2006) conference in Philadelphia last Tuesday. The conference is held as part of the ASME International Design Engineering Technical Conferences (IDETC 2006) . Yan Jin invited me to join the panel he organized on Intelligent Systems and Innovation. I had a great time joining the DTM people, very interesting work—if you are interested on innovation and creativity. ...