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Lemmatisation
Lemmatization (or less commonly lemmatisation) in linguistics is the process of grouping together the inflected forms of a word so they can be analysed as a single item, identified by the word's lemma, or dictionary form. In computational linguistics, lemmatization is the algorithmic process of determining the lemma of a word based on its intended meaning. Unlike stemming, lemmatization depends on correctly identifying the intended part of speech and meaning of a word in a sentence, as well as within the larger context surrounding that sentence, such as neighbouring sentences or even an entire document. As a result, developing efficient lemmatization algorithms is an open area of research. Description In many languages, words appear in several ''inflected'' forms. For example, in English, the verb 'to walk' may appear as 'walk', 'walked', 'walks' or 'walking'. The base form, 'walk', that one might look up in a dictionary, is called the ''lemma'' for the word. The association o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stemming
In linguistic morphology and information retrieval, stemming is the process of reducing inflected (or sometimes derived) words to their word stem, base or root form—generally a written word form. The stem need not be identical to the morphological root of the word; it is usually sufficient that related words map to the same stem, even if this stem is not in itself a valid root. Algorithms for stemming have been studied in computer science since the 1960s. Many search engines treat words with the same stem as synonyms as a kind of query expansion, a process called conflation. A computer program or subroutine that stems word may be called a ''stemming program'', ''stemming algorithm'', or ''stemmer''. Examples A stemmer for English operating on the stem ''cat'' should identify such strings as ''cats'', ''catlike'', and ''catty''. A stemming algorithm might also reduce the words ''fishing'', ''fished'', and ''fisher'' to the stem ''fish''. The stem need not be a word, for example ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linguistics
Linguistics is the scientific study of language. The areas of linguistic analysis are syntax (rules governing the structure of sentences), semantics (meaning), Morphology (linguistics), morphology (structure of words), phonetics (speech sounds and equivalent gestures in sign languages), phonology (the abstract sound system of a particular language, and analogous systems of sign languages), and pragmatics (how the context of use contributes to meaning). Subdisciplines such as biolinguistics (the study of the biological variables and evolution of language) and psycholinguistics (the study of psychological factors in human language) bridge many of these divisions. Linguistics encompasses Outline of linguistics, many branches and subfields that span both theoretical and practical applications. Theoretical linguistics is concerned with understanding the universal grammar, universal and Philosophy of language#Nature of language, fundamental nature of language and developing a general ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rule-based System
In computer science, a rule-based system is a computer system in which domain-specific knowledge is represented in the form of rules and general-purpose reasoning is used to solve problems in the domain. Two different kinds of rule-based systems emerged within the field of artificial intelligence in the 1970s: * Production systems, which use ''if-then rules'' to derive ''actions'' from ''conditions''. * Logic programming systems, which use ''conclusion if conditions rules'' to derive ''conclusions'' from ''conditions''. The differences and relationships between these two kinds of rule-based system has been a major source of misunderstanding and confusion. Both kinds of rule-based systems use either forward or backward chaining, in contrast with imperative programs, which execute commands listed sequentially. However, logic programming systems have a logical interpretation, whereas production systems do not. Production system rules A classic example of a production rule-b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computational Linguistics
Computational linguistics is an interdisciplinary field concerned with the computational modelling of natural language, as well as the study of appropriate computational approaches to linguistic questions. In general, computational linguistics draws upon linguistics, computer science, artificial intelligence, mathematics, logic, philosophy, cognitive science, cognitive psychology, psycholinguistics, anthropology and neuroscience, among others. Computational linguistics is closely related to mathematical linguistics. Origins The field overlapped with artificial intelligence since the efforts in the United States in the 1950s to use computers to automatically translate texts from foreign languages, particularly Russian scientific journals, into English. Since rule-based approaches were able to make arithmetic (systematic) calculations much faster and more accurately than humans, it was expected that lexicon, morphology, syntax and semantics can be learned using explicit rules, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Biomedical Semantics
The ''Journal of Biomedical Semantics'' is a peer-reviewed open-access scientific journal that covers biomedical semantics. History It was established in 2010 and is published by BioMed Central. The editors-in-chief are Dietrich Rebholz-Schuhmann (University of Zurich) and Goran Nenadic (University of Manchester). The journal is abstracted and indexed in Scopus, Science Citation Index Expanded, and BIOSIS Previews BIOSIS Previews is an English-language, bibliographic database service, with abstracts and citation indexing. It is part of ''Clarivate Analytics Web of Science'' suite. BIOSIS Previews indexes data from 1926 to the present. BIOSIS Previews i .... References External links * Biomedical informatics journals Creative Commons Attribution-licensed journals BioMed Central academic journals Academic journals established in 2010 English-language journals {{compu-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Text Corpus
In linguistics and natural language processing, a corpus (: corpora) or text corpus is a dataset, consisting of natively digital and older, digitalized, language resources, either annotated or unannotated. Annotated, they have been used in corpus linguistics for statistical statistical hypothesis testing, hypothesis testing, checking occurrences or validating linguistic rules within a specific language territory. Overview A corpus may contain texts in a single language (''monolingual corpus'') or text data in multiple languages (''multilingual corpus''). In order to make the corpora more useful for doing linguistic research, they are often subjected to a process known as annotation. An example of annotating a corpus is part-of-speech tagging, or ''POS-tagging'', in which information about each word's part of speech (verb, noun, adjective, etc.) is added to the corpus in the form of ''tags''. Another example is indicating the Lemma (morphology), lemma (base) form of each word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Text Annotation
Text annotation is the practice and the result of adding a note or gloss to a text, which may include highlights or underlining, comments, footnotes, tags, and links. Text annotations can include notes written for a reader's private purposes, as well as shared annotations written for the purposes of collaborative writing and editing, commentary, or social reading and sharing. In some fields, text annotation is comparable to metadata insofar as it is added post hoc and provides information about a text without fundamentally altering that original text. Text annotations are sometimes referred to as marginalia, though some reserve this term specifically for hand-written notes made in the margins of books or manuscripts. Annotations have been found to be useful and help to develop knowledge of English literature. Annotations can be both private and socially shared, including hand-written and information technology-based annotation. Annotations are different than notetaking because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compound (linguistics)
In linguistics, a compound is a lexeme (less precisely, a word or Sign language, sign) that consists of more than one Word stem, stem. Compounding, composition or nominal composition is the process of word formation that creates compound lexemes. Compounding occurs when two or more words or signs are joined to make a longer word or sign. Consequently, a compound is a unit composed of more than one stem, forming words or signs. If the joining of the words or signs is orthographically represented with a hyphen, the result is a hyphenated compound (e.g., ''must-have'', ''hunter-gatherer)''. If they are joined without an intervening space, it is a closed compound (e.g., ''footpath'', ''blackbird''). If they are joined with a space (e.g. ''school bus, high school, lowest common denominator''), then the result – at least in English – may be an open compound. The meaning of the compound may be similar to or different from the meaning of its components in isolation. The component stem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precision And Recall
In pattern recognition, information retrieval, object detection and classification (machine learning), precision and recall are performance metrics that apply to data retrieved from a collection, corpus or sample space. Precision (also called positive predictive value) is the fraction of relevant instances among the retrieved instances. Written as a formula: \text = \frac Recall (also known as sensitivity) is the fraction of relevant instances that were retrieved. Written as a formula: \text = \frac Both precision and recall are therefore based on relevance. Consider a computer program for recognizing dogs (the relevant element) in a digital photograph. Upon processing a picture which contains ten cats and twelve dogs, the program identifies eight dogs. Of the eight elements identified as dogs, only five actually are dogs ( true positives), while the other three are cats ( false positives). Seven dogs were missed ( false negatives), and seven cats were correctly ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apache Lucene
Apache Lucene is a free and open-source search engine software library, originally written in Java by Doug Cutting. It is supported by the Apache Software Foundation and is released under the Apache Software License. Lucene is widely used as a standard foundation for production search applications. Lucene has been ported to other programming languages including Object Pascal, Perl, C#, C++, Python, Ruby and PHP. History Doug Cutting originally wrote Lucene in 1999. Lucene was his fifth search engine. He had previously written two while at Xerox PARC, one at Apple, and a fourth at Excite. It was initially available for download from its home at the SourceForge web site. It joined the Apache Software Foundation's Jakarta family of open-source Java products in September 2001 and became its own top-level Apache project in February 2005. The name Lucene is Doug Cutting's wife's middle name and her maternal grandmother's first name. Lucene formerly included a number of sub-p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflection
In linguistic Morphology (linguistics), morphology, inflection (less commonly, inflexion) is a process of word formation in which a word is modified to express different grammatical category, grammatical categories such as grammatical tense, tense, grammatical case, case, grammatical voice, voice, grammatical aspect, aspect, grammatical person, person, grammatical number, number, grammatical gender, gender, grammatical mood, mood, animacy, and definiteness. The inflection of verbs is called ''grammatical conjugation, conjugation'', while the inflection of nouns, adjectives, adverbs, etc. can be called ''declension''. An inflection expresses grammatical categories with affixation (such as prefix, suffix, infix, circumfix, and transfix), apophony (as Indo-European ablaut), or other modifications. For example, the Latin verb ', meaning "I will lead", includes the suffix ', expressing person (first), number (singular), and tense-mood (future indicative or present subjunctive). Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
