Prof. Michalis Vazirgiannis
(DASCIM), LIX, Ecole Polytechnique, Palaiseau, France
Title: "Graph-of-word: boosting text mining with graphs"
Abstract: The Bag-of-words model has been the dominant approach for IR and Text mining for many years assuming the word independence and the frequencies as the main elements for feature selection and query to document similarity computation. Although the long and successful usage, bag-of-words ignores words' order and distance within the document – weakening thus the expressive power of the distance metrics. We propose graph-of-word, an alternative approach that capitalizes on a graph representation of documents and challenges the word independence assumption by taking into account words' order and distance. We applied graph-of-word in various tasks such as ad-hoc Information Retrieval, Single-Document Keyword Extraction, Text Categorization and Sub-event Detection in Textual Streams. In all cases the graph of word approach, assisted by graph degeneracy at times, outperforms the state of the art base lines.
Short Biography: Dr. Vazirgiannis is a Professor at LIX, Ecole Polytechnique in France.
He holds a degree in Physics and a PhD in Informatics from Athens University(Greece) and a Master degree in AI from HerioWatt Univ Edinburgh. He has conducted research in GMD-IPSI, Max Planck MPI (Germany), in INRIA/FUTURS (Paris). He has been a teaching in AUEB (Greece), Ecole Polytechnique, Telecom-Paristech, ENS (France), Tsinghua, Jiaotong Shanghai (China) and in Deusto University (Spain).
His current research interests are on machine learning and combinatorial methods for Graph analysis (including community detection, graph clustering and embeddings, influence maximization), Text mining including Graph of Words, word embeddings with applications to web advertising and marketing, event detection and summarization. He has active cooperation with industrial partners in the area of data analytics and machine learning for large scale data repositories in different application domains. He has supervised fifteen completed PhD theses. He has published three books and more than a 150 papers in international refereed journals and conferences.
He has organized large scale conferences in the area of Data Mining and Machine Learning (such as ECML/PKDD) while he participates in the senior PC of AI and ML conferences – such as AAAI and IJCAI, He has received the ERCIM and the Marie Curie EU fellowships and since 2015 he leads the AXA Data Science chair.
Dr Yiannis Kompatsiaris
Multimedia, Knowledge and Social Media Analytics Lab, Information Technologies Institute, Greece
Short Biography: Tbc