题 目（TITLE）：Learning of positive and negative patterns for relation extraction
讲 座 人（SPEAKER）: Professor Hans Uszkoreit；Saarland University, Germany
主 持 人 (CHAIR)：Prof. Chengqing Zong
时 间 (TIME)：10:00am, November 2nd, 2009
地 点 (VENUE)： 1115, 11th floor
Minimally supervised machine learning methods based on bootstrapping are an attractive approach to advanced information extraction. Complex patterns sigalling relevant semantic relations in free texts can be detected in this way. However, the potential and limitations of such methods are not yet sufficiently understood. We have systematically analyzed a bootstrapping approach. The starting point of the analysis is a pattern-learning graph, which is a subgraph of the bipartite graph representing all connections between linguistic patterns and relation instances exhibited by the data. It is shown that the performance of such general learning framework for actual tasks is dependent on certain properties of the data and on the seed construction. However, the greatest improvements can be obtained through the systematic learning of negative patterns.
Hans Uszkoreit is Professor of Computational Linguistics at Saarland University. At the same time he serves as Scientific Director at the German Research Center for Artificial Intelligence (DFKI) where he heads the DFKI Language Technology Lab. By cooptation he is also Professor of the Computer Science Department.
Uszkoreit is Permanent Member of the International Committee of Computational Linguistics (ICCL), Member of the European Academy of Sciences, Past President of the European Association for Logic, Language and Information, Member of the Executive Board of the European Network of Language and Speech, Member of the Board of the European Language Resources Association (ELRA), and serves on several international editorial and advisory boards. He is co-founder and Board Member of XtraMind Technologies GmbH, Saarbruecken, acrolinx gmbh, Berlin and Yocoy Technologies GmbH, Berlin. Since 2006, he serves as Chairman of the Board of Directors of the international initiative dropping knowledge.
His current research interests are computer models of natural language understanding and production, advanced applications of language and knowledge technologies such as semantic information systems, translingual technologies, cognitive foundations of language and knowledge, deep linguistic processing of natural language, syntax and semantics of natural language and the grammar of German.