To respond to queries that relate to co-occurring entities on the Web, a compact sparse matrix representing entity co-occurrences is generated and then accessed to satisfy queries. The sparse matrix has groups of sub-rows, with each group corresponding to an entity in a document corpus. The groups are...http://www.google.com.hk/patents/US7587407?utm_source=gb-gplus-share專利 US7587407 - System and method for creation, representation, and delivery of document corpus entity co-occurrence information
