{"id":"https://openalex.org/W2067407057","doi":"https://doi.org/10.1016/s0019-9958(81)90170-4","title":"Left universal context-free grammars and homomorphic characterizations of languages","display_name":"Left universal context-free grammars and homomorphic characterizations of languages","publication_year":1981,"publication_date":"1981-08-01","ids":{"openalex":"https://openalex.org/W2067407057","doi":"https://doi.org/10.1016/s0019-9958(81)90170-4","mag":"2067407057"},"language":"en","primary_location":{"id":"doi:10.1016/s0019-9958(81)90170-4","is_oa":false,"landing_page_url":"https://doi.org/10.1016/s0019-9958(81)90170-4","pdf_url":null,"source":{"id":"https://openalex.org/S4210192454","display_name":"Information and Control","issn_l":"0019-9958","issn":["0019-9958","1878-2981"],"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/P4310319955","host_organization_name":"Academic Press","host_organization_lineage":["https://openalex.org/P4310319955","https://openalex.org/P4310320990"],"host_organization_lineage_names":["Academic Press","Elsevier BV"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Information and Control","raw_type":"journal-article"},"type":"article","indexed_in":["crossref"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5102120352","display_name":"Sadaki Hirose","orcid":null},"institutions":[{"id":"https://openalex.org/I201537933","display_name":"Tohoku University","ror":"https://ror.org/01dq60k83","country_code":"JP","type":"education","lineage":["https://openalex.org/I201537933"]}],"countries":["JP"],"is_corresponding":false,"raw_author_name":"Sadaki Hirose","raw_affiliation_strings":["Research Institute of Electrical Communication, Tohoku University, Sendai, Japan;"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Research Institute of Electrical Communication, Tohoku University, Sendai, Japan;","institution_ids":["https://openalex.org/I201537933"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5004909783","display_name":"Masakazu Nasu","orcid":null},"institutions":[{"id":"https://openalex.org/I201537933","display_name":"Tohoku University","ror":"https://ror.org/01dq60k83","country_code":"JP","type":"education","lineage":["https://openalex.org/I201537933"]}],"countries":["JP"],"is_corresponding":false,"raw_author_name":"Masakazu Nasu","raw_affiliation_strings":["Research Institute of Electrical Communication, Tohoku University, Sendai, Japan;"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Research Institute of Electrical Communication, Tohoku University, Sendai, Japan;","institution_ids":["https://openalex.org/I201537933"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":[],"corresponding_institution_ids":["https://openalex.org/I201537933"],"apc_list":null,"apc_paid":null,"fwci":0.0,"has_fulltext":false,"cited_by_count":10,"citation_normalized_percentile":{"value":0.22748414,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":90,"max":94},"biblio":{"volume":"50","issue":"2","first_page":"110","last_page":"118"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11567","display_name":"semigroups and automata theory","score":0.9998999834060669,"subfield":{"id":"https://openalex.org/subfields/1703","display_name":"Computational Theory and Mathematics"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T11567","display_name":"semigroups and automata theory","score":0.9998999834060669,"subfield":{"id":"https://openalex.org/subfields/1703","display_name":"Computational Theory and Mathematics"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10181","display_name":"Natural Language Processing Techniques","score":0.9854000210762024,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10126","display_name":"Logic, programming, and type systems","score":0.9850999712944031,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/rule-based-machine-translation","display_name":"Rule-based machine translation","score":0.7646389007568359},{"id":"https://openalex.org/keywords/context-free-grammar","display_name":"Context-free grammar","score":0.7575355768203735},{"id":"https://openalex.org/keywords/homomorphic-encryption","display_name":"Homomorphic encryption","score":0.728610634803772},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.6032182574272156},{"id":"https://openalex.org/keywords/tree-adjoining-grammar","display_name":"Tree-adjoining grammar","score":0.5472126603126526},{"id":"https://openalex.org/keywords/programming-language","display_name":"Programming language","score":0.5284744501113892},{"id":"https://openalex.org/keywords/context","display_name":"Context (archaeology)","score":0.46064168214797974},{"id":"https://openalex.org/keywords/indexed-grammar","display_name":"Indexed grammar","score":0.44633492827415466},{"id":"https://openalex.org/keywords/context-sensitive-grammar","display_name":"Context-sensitive grammar","score":0.4138606786727905},{"id":"https://openalex.org/keywords/natural-language-processing","display_name":"Natural language processing","score":0.34909963607788086},{"id":"https://openalex.org/keywords/biology","display_name":"Biology","score":0.12656238675117493}],"concepts":[{"id":"https://openalex.org/C53893814","wikidata":"https://www.wikidata.org/wiki/Q7378909","display_name":"Rule-based machine translation","level":2,"score":0.7646389007568359},{"id":"https://openalex.org/C97212296","wikidata":"https://www.wikidata.org/wiki/Q338047","display_name":"Context-free grammar","level":3,"score":0.7575355768203735},{"id":"https://openalex.org/C158338273","wikidata":"https://www.wikidata.org/wiki/Q2154943","display_name":"Homomorphic encryption","level":3,"score":0.728610634803772},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.6032182574272156},{"id":"https://openalex.org/C134083981","wikidata":"https://www.wikidata.org/wiki/Q1754022","display_name":"Tree-adjoining grammar","level":4,"score":0.5472126603126526},{"id":"https://openalex.org/C199360897","wikidata":"https://www.wikidata.org/wiki/Q9143","display_name":"Programming language","level":1,"score":0.5284744501113892},{"id":"https://openalex.org/C2779343474","wikidata":"https://www.wikidata.org/wiki/Q3109175","display_name":"Context (archaeology)","level":2,"score":0.46064168214797974},{"id":"https://openalex.org/C79243999","wikidata":"https://www.wikidata.org/wiki/Q6590011","display_name":"Indexed grammar","level":5,"score":0.44633492827415466},{"id":"https://openalex.org/C125950753","wikidata":"https://www.wikidata.org/wiki/Q908674","display_name":"Context-sensitive grammar","level":4,"score":0.4138606786727905},{"id":"https://openalex.org/C204321447","wikidata":"https://www.wikidata.org/wiki/Q30642","display_name":"Natural language processing","level":1,"score":0.34909963607788086},{"id":"https://openalex.org/C86803240","wikidata":"https://www.wikidata.org/wiki/Q420","display_name":"Biology","level":0,"score":0.12656238675117493},{"id":"https://openalex.org/C148730421","wikidata":"https://www.wikidata.org/wiki/Q141090","display_name":"Encryption","level":2,"score":0.0},{"id":"https://openalex.org/C151730666","wikidata":"https://www.wikidata.org/wiki/Q7205","display_name":"Paleontology","level":1,"score":0.0},{"id":"https://openalex.org/C111919701","wikidata":"https://www.wikidata.org/wiki/Q9135","display_name":"Operating system","level":1,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1016/s0019-9958(81)90170-4","is_oa":false,"landing_page_url":"https://doi.org/10.1016/s0019-9958(81)90170-4","pdf_url":null,"source":{"id":"https://openalex.org/S4210192454","display_name":"Information and Control","issn_l":"0019-9958","issn":["0019-9958","1878-2981"],"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/P4310319955","host_organization_name":"Academic Press","host_organization_lineage":["https://openalex.org/P4310319955","https://openalex.org/P4310320990"],"host_organization_lineage_names":["Academic Press","Elsevier BV"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Information and Control","raw_type":"journal-article"}],"best_oa_location":null,"sustainable_development_goals":[{"id":"https://metadata.un.org/sdg/4","score":0.7900000214576721,"display_name":"Quality Education"}],"awards":[],"funders":[],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":10,"referenced_works":["https://openalex.org/W299519334","https://openalex.org/W1535681052","https://openalex.org/W1989491812","https://openalex.org/W2002089154","https://openalex.org/W2060894864","https://openalex.org/W2077948235","https://openalex.org/W2148224873","https://openalex.org/W2188913344","https://openalex.org/W2914032487","https://openalex.org/W4302339081"],"related_works":["https://openalex.org/W2403874525","https://openalex.org/W2153803459","https://openalex.org/W1608157979","https://openalex.org/W37677999","https://openalex.org/W2792956200","https://openalex.org/W2041988689","https://openalex.org/W3008122807","https://openalex.org/W1998938240","https://openalex.org/W1255264663","https://openalex.org/W2067980891"],"abstract_inverted_index":null,"counts_by_year":[{"year":2019,"cited_by_count":1},{"year":2016,"cited_by_count":1}],"updated_date":"2025-11-06T03:46:38.306776","created_date":"2025-10-10T00:00:00"}
