We present Biased LexRank, a method for semi-supervised passage retrieval in the context of question answering. We represent a text as a graph of passages linked based on their pairwise lexical similarity. We use traditional passage retrieval techniques to identify passages that are likely to be relevant to a user’s natural language question. We then perform a random walk on the lexical similar...

Current research in the field of automatic plagiarism detection for text documents focuses on the development of algorithms that compare suspicious documents against potential original documents. Although recent approaches perform well in identifying copied or even modified passages [Brin 1995, Stein 2005], they assume a closed world where a reference collection must be given [Finkel 2002]. Rec...

With uridine kinase activity used as a marker characteristic, changes were studied in the cellular composition of populations which consisted of resistant and sensitive ELD ascites cells, mixed artificially in various known proportions, and which were either treat ed or not treated with 5-fluorouracil (FU) in the course of subsequent intraperitoneal passages in mice. The resistant cells had a g...

In this paper we propose a method for unsupervised learning of relation between terms in questions and answer passages by using the Web as corpus. The method involves automatic acquisition of relevant answer passages from the Web for a set of questions and answers, as well as alignment of wh -phrases and keywords in questions with phrases in the answer passages. At run time, wh-phrases and keyw...