{"id":"https://openalex.org/W1945946994","doi":"https://doi.org/10.1007/3-540-54009-1_3","title":"A relational algebra for complex objects based on partial information","display_name":"A relational algebra for complex objects based on partial information","publication_year":1991,"publication_date":"1991-01-01","ids":{"openalex":"https://openalex.org/W1945946994","doi":"https://doi.org/10.1007/3-540-54009-1_3","mag":"1945946994"},"language":"en","primary_location":{"id":"doi:10.1007/3-540-54009-1_3","is_oa":false,"landing_page_url":"https://doi.org/10.1007/3-540-54009-1_3","pdf_url":null,"source":{"id":"https://openalex.org/S106296714","display_name":"Lecture notes in computer science","issn_l":"0302-9743","issn":["0302-9743","1611-3349"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319900","host_organization_name":"Springer Science+Business Media","host_organization_lineage":["https://openalex.org/P4310319900","https://openalex.org/P4310319965"],"host_organization_lineage_names":["Springer Science+Business Media","Springer Nature"],"type":"book series"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Lecture Notes in Computer Science","raw_type":"book-chapter"},"type":"book-chapter","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/A5069883356","display_name":"Leonid Libkin","orcid":"https://orcid.org/0000-0002-6698-2735"},"institutions":[{"id":"https://openalex.org/I79576946","display_name":"University of Pennsylvania","ror":"https://ror.org/00b30xv10","country_code":"US","type":"education","lineage":["https://openalex.org/I79576946"]}],"countries":["US"],"is_corresponding":true,"raw_author_name":"Leonid Libkin","raw_affiliation_strings":["Department of Computer and Information Science, University of Pennsylvania, 19104, Philadelphia, PA, USA","Department of Computer and Information Science, University of Pennsylvania, Philadelphia, USA"],"affiliations":[{"raw_affiliation_string":"Department of Computer and Information Science, University of Pennsylvania, 19104, Philadelphia, PA, USA","institution_ids":["https://openalex.org/I79576946"]},{"raw_affiliation_string":"Department of Computer and Information Science, University of Pennsylvania, Philadelphia, USA","institution_ids":["https://openalex.org/I79576946"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":["https://openalex.org/A5069883356"],"corresponding_institution_ids":["https://openalex.org/I79576946"],"apc_list":{"value":5000,"currency":"EUR","value_usd":5392},"apc_paid":null,"fwci":6.1047,"has_fulltext":false,"cited_by_count":29,"citation_normalized_percentile":{"value":0.96664443,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":null,"biblio":{"volume":null,"issue":null,"first_page":"29","last_page":"43"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10317","display_name":"Advanced Database Systems and Queries","score":0.9994999766349792,"subfield":{"id":"https://openalex.org/subfields/1705","display_name":"Computer Networks and Communications"},"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/T10317","display_name":"Advanced Database Systems and Queries","score":0.9994999766349792,"subfield":{"id":"https://openalex.org/subfields/1705","display_name":"Computer Networks and Communications"},"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/T10215","display_name":"Semantic Web and Ontologies","score":0.9976000189781189,"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/T11106","display_name":"Data Management and Algorithms","score":0.9954000115394592,"subfield":{"id":"https://openalex.org/subfields/1711","display_name":"Signal Processing"},"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/relational-algebra","display_name":"Relational algebra","score":0.7887516617774963},{"id":"https://openalex.org/keywords/cartesian-product","display_name":"Cartesian product","score":0.7318640947341919},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.682077169418335},{"id":"https://openalex.org/keywords/extension","display_name":"Extension (predicate logic)","score":0.6555703282356262},{"id":"https://openalex.org/keywords/relational-calculus","display_name":"Relational calculus","score":0.6435916423797607},{"id":"https://openalex.org/keywords/projection","display_name":"Projection (relational algebra)","score":0.6111553311347961},{"id":"https://openalex.org/keywords/relational-database","display_name":"Relational database","score":0.5531415939331055},{"id":"https://openalex.org/keywords/relation","display_name":"Relation (database)","score":0.5481616854667664},{"id":"https://openalex.org/keywords/algebra-over-a-field","display_name":"Algebra over a field","score":0.53480064868927},{"id":"https://openalex.org/keywords/set","display_name":"Set (abstract data type)","score":0.5170581936836243},{"id":"https://openalex.org/keywords/theoretical-computer-science","display_name":"Theoretical computer science","score":0.515489399433136},{"id":"https://openalex.org/keywords/relational-model","display_name":"Relational model","score":0.4954787492752075},{"id":"https://openalex.org/keywords/domain","display_name":"Domain (mathematical analysis)","score":0.486479252576828},{"id":"https://openalex.org/keywords/scheme","display_name":"Scheme (mathematics)","score":0.48231935501098633},{"id":"https://openalex.org/keywords/functional-dependency","display_name":"Functional dependency","score":0.48077696561813354},{"id":"https://openalex.org/keywords/space","display_name":"Space (punctuation)","score":0.4268896281719208},{"id":"https://openalex.org/keywords/dependency","display_name":"Dependency (UML)","score":0.4181116223335266},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.3202308416366577},{"id":"https://openalex.org/keywords/discrete-mathematics","display_name":"Discrete mathematics","score":0.30461007356643677},{"id":"https://openalex.org/keywords/algorithm","display_name":"Algorithm","score":0.28637754917144775},{"id":"https://openalex.org/keywords/pure-mathematics","display_name":"Pure mathematics","score":0.20326948165893555},{"id":"https://openalex.org/keywords/data-mining","display_name":"Data mining","score":0.18689733743667603},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.16855040192604065},{"id":"https://openalex.org/keywords/programming-language","display_name":"Programming language","score":0.1087668240070343}],"concepts":[{"id":"https://openalex.org/C95916125","wikidata":"https://www.wikidata.org/wiki/Q840540","display_name":"Relational algebra","level":3,"score":0.7887516617774963},{"id":"https://openalex.org/C65236422","wikidata":"https://www.wikidata.org/wiki/Q173740","display_name":"Cartesian product","level":2,"score":0.7318640947341919},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.682077169418335},{"id":"https://openalex.org/C2778029271","wikidata":"https://www.wikidata.org/wiki/Q5421931","display_name":"Extension (predicate logic)","level":2,"score":0.6555703282356262},{"id":"https://openalex.org/C99436015","wikidata":"https://www.wikidata.org/wiki/Q1722436","display_name":"Relational calculus","level":4,"score":0.6435916423797607},{"id":"https://openalex.org/C57493831","wikidata":"https://www.wikidata.org/wiki/Q3134666","display_name":"Projection (relational algebra)","level":2,"score":0.6111553311347961},{"id":"https://openalex.org/C5655090","wikidata":"https://www.wikidata.org/wiki/Q192588","display_name":"Relational database","level":2,"score":0.5531415939331055},{"id":"https://openalex.org/C25343380","wikidata":"https://www.wikidata.org/wiki/Q277521","display_name":"Relation (database)","level":2,"score":0.5481616854667664},{"id":"https://openalex.org/C136119220","wikidata":"https://www.wikidata.org/wiki/Q1000660","display_name":"Algebra over a field","level":2,"score":0.53480064868927},{"id":"https://openalex.org/C177264268","wikidata":"https://www.wikidata.org/wiki/Q1514741","display_name":"Set (abstract data type)","level":2,"score":0.5170581936836243},{"id":"https://openalex.org/C80444323","wikidata":"https://www.wikidata.org/wiki/Q2878974","display_name":"Theoretical computer science","level":1,"score":0.515489399433136},{"id":"https://openalex.org/C40207289","wikidata":"https://www.wikidata.org/wiki/Q755662","display_name":"Relational model","level":3,"score":0.4954787492752075},{"id":"https://openalex.org/C36503486","wikidata":"https://www.wikidata.org/wiki/Q11235244","display_name":"Domain (mathematical analysis)","level":2,"score":0.486479252576828},{"id":"https://openalex.org/C77618280","wikidata":"https://www.wikidata.org/wiki/Q1155772","display_name":"Scheme (mathematics)","level":2,"score":0.48231935501098633},{"id":"https://openalex.org/C26320393","wikidata":"https://www.wikidata.org/wiki/Q597053","display_name":"Functional dependency","level":3,"score":0.48077696561813354},{"id":"https://openalex.org/C2778572836","wikidata":"https://www.wikidata.org/wiki/Q380933","display_name":"Space (punctuation)","level":2,"score":0.4268896281719208},{"id":"https://openalex.org/C19768560","wikidata":"https://www.wikidata.org/wiki/Q320727","display_name":"Dependency (UML)","level":2,"score":0.4181116223335266},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.3202308416366577},{"id":"https://openalex.org/C118615104","wikidata":"https://www.wikidata.org/wiki/Q121416","display_name":"Discrete mathematics","level":1,"score":0.30461007356643677},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.28637754917144775},{"id":"https://openalex.org/C202444582","wikidata":"https://www.wikidata.org/wiki/Q837863","display_name":"Pure mathematics","level":1,"score":0.20326948165893555},{"id":"https://openalex.org/C124101348","wikidata":"https://www.wikidata.org/wiki/Q172491","display_name":"Data mining","level":1,"score":0.18689733743667603},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.16855040192604065},{"id":"https://openalex.org/C199360897","wikidata":"https://www.wikidata.org/wiki/Q9143","display_name":"Programming language","level":1,"score":0.1087668240070343},{"id":"https://openalex.org/C111919701","wikidata":"https://www.wikidata.org/wiki/Q9135","display_name":"Operating system","level":1,"score":0.0},{"id":"https://openalex.org/C134306372","wikidata":"https://www.wikidata.org/wiki/Q7754","display_name":"Mathematical analysis","level":1,"score":0.0}],"mesh":[],"locations_count":2,"locations":[{"id":"doi:10.1007/3-540-54009-1_3","is_oa":false,"landing_page_url":"https://doi.org/10.1007/3-540-54009-1_3","pdf_url":null,"source":{"id":"https://openalex.org/S106296714","display_name":"Lecture notes in computer science","issn_l":"0302-9743","issn":["0302-9743","1611-3349"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319900","host_organization_name":"Springer Science+Business Media","host_organization_lineage":["https://openalex.org/P4310319900","https://openalex.org/P4310319965"],"host_organization_lineage_names":["Springer Science+Business Media","Springer Nature"],"type":"book series"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Lecture Notes in Computer Science","raw_type":"book-chapter"},{"id":"pmh:oai:CiteSeerX.psu:10.1.1.55.3332","is_oa":false,"landing_page_url":"http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.55.3332","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"ftp://ftp.cis.upenn.edu/pub/papers/db-research/mfdbs91.ps.Z","raw_type":"text"}],"best_oa_location":null,"sustainable_development_goals":[],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":31,"referenced_works":["https://openalex.org/W26246528","https://openalex.org/W288430805","https://openalex.org/W1486310914","https://openalex.org/W1503312825","https://openalex.org/W1544564247","https://openalex.org/W1585806150","https://openalex.org/W1596560506","https://openalex.org/W1605913309","https://openalex.org/W1967969348","https://openalex.org/W1969375478","https://openalex.org/W1990391007","https://openalex.org/W2019156246","https://openalex.org/W2054969282","https://openalex.org/W2060728344","https://openalex.org/W2066837227","https://openalex.org/W2089781037","https://openalex.org/W2096744626","https://openalex.org/W2109221906","https://openalex.org/W2133277328","https://openalex.org/W2143990139","https://openalex.org/W2153320571","https://openalex.org/W2489748212","https://openalex.org/W2587041094","https://openalex.org/W2912883082","https://openalex.org/W3023519444","https://openalex.org/W4213381987","https://openalex.org/W4240624163","https://openalex.org/W4251927117","https://openalex.org/W6629123387","https://openalex.org/W6674733845","https://openalex.org/W6815558393"],"related_works":["https://openalex.org/W2089781037","https://openalex.org/W2085988990","https://openalex.org/W2056340443","https://openalex.org/W2005835473","https://openalex.org/W1516375613","https://openalex.org/W2095263945","https://openalex.org/W2243465518","https://openalex.org/W1969375478","https://openalex.org/W2378275298","https://openalex.org/W2049150522"],"abstract_inverted_index":null,"counts_by_year":[],"updated_date":"2026-04-04T16:13:02.066488","created_date":"2025-10-10T00:00:00"}