V O R T R A G ********************** Oesterreichisches Forschungsinstitut fuer Artificial Intelligence(OFAI) der OSGK Freyung 6/6, A-1010 Wien Tel: +43-1-5336112-17, Fax: +43-1-5336112-77, Email: sec@ofai.at Nenad Tomasev Artificial Intelligence Laboratory Jozef Stefan Institute Ljubljana, Slovenia "THE ROLE OF HUBS IN HIGH-DIMENSIONAL DATA ANALYSIS" Many important data types are inherently high-dimensional, as they require many features to be properly represented. This includes, but is not limited to: text, images, sensor data, music/audio files, etc. Analyzing such high-dimensional data is known to be difficult, for many reasons. Sparsity might be the most obvious problem, though there are other, more subtle issues at hand. Inherently high-dimensional data gives rise to hubs, very influential points in the k-nearest neighbor topology. Hub-points are retrieved very often during similarity search, while most other points receive little to no attention during the learning process. This skewed distribution of influence affects many data mining methods, often in very negative ways. We will show some initial steps that we have been taking towards designing hubness-aware data mining and machine learning methods. This includes classification, clustering and metric learning. ********* Time: Thursday, 28th February 2013, 6.30 p.m. sharp Location: Oesterreichisches Forschungsinstitut fuer Artificial Intelligence, OFAI Freyung 6, Stiege 6, 1010 Wien OESTERREICHISCHES FORSCHUNGSINSTITUT FUER ARTIFICIAL INTELLIGENCE Univ.-Prof. Ing. Dr. Robert Trappl, MBA *********