A particular problem of searching news archives with named entities is that they are very dynamic in appearance compared to other vocabulary terms, and synonym relationships between terms change with time. In previous work, we proposed an approach to extracting time-based synonyms of named entities from the whole history of Wikipedia. In this paper, we present QUEST (Query Expansion using Synon...

Query substitution replaces original query words with a new words that express the same meaning. In this paper, the technique of n-gram analysis is proposed to find the synonyms or quasi-synonyms of the original query word. The synonyms found are then incorporated into the original query with different methods. Experiments show that the proposed n-gram analysis techniques can obtain interesting...

Concept mapping is important in natural language processing (NLP) for bioinformatics. The UMLS Metathesaurus provides a rich synonym thesaurus and is a popular resource for concept mapping. Query expansion using synonyms for subterm substitutions is an effective technique to increase recall for UMLS concept mapping. Synonyms used to substitute subterms are called element synonyms. The completen...

Building a Linguistic Resource (LR) is a task requiring a huge quantitative of means, human resources and funds. Though finalization of the development phase and assessment of the produced resource, necessarily require human involvement, a computer aided process for building the resource’s initial structure would greatly reduce the overall effort to be undertaken. We present here a novel approa...

It is shown that basic language processes such as the production of free word associations and the generation of synonyms can be simulated using statistical models that analyze the distribution of words in large text corpora. According to the law of association by contiguity, the acquisition of word associations can be explained by Hebbian learning. The free word associations as produced by sub...

Distributional measures of semantic relatedness determine word similarity based on how frequently a pair of words appear in the same contexts. A typical method is to construct a word-context matrix, then re-weight it using some measure of association, and finally take the vector distance as a measure of similarity. This has largely been an unsupervised process, but in recent years more work has...

Turney (2001) has shown that computing the mutual information of a pair of words by using cooccurrence counts obtained via queries to the AltaVista search engine performs very effectively in a synonym detection task. Since manual synonym detection is a challenging task for terminologists, we investigate whether the AltaVista-based Mutual Information (AVMI) method can be applied to the task of f...

Chapter 4. Lissencephaly, Type I 35 DEFINITION Lissencephaly, derived from the Greek works “lissos” meaning smooth and “enkephalos” which means brain, is a descriptive term defining a class of human cerebral malformations characterized by the agyric surface of the brain. In fact, most cases of lissencephaly do not have a complete loss of gyri; often the most ventral and medial gyri are relative...