{"id":"https://openalex.org/W3000294563","doi":"https://doi.org/10.37236/114","title":"Restrictions and Generalizations on Comma-Free Codes","display_name":"Restrictions and Generalizations on Comma-Free Codes","publication_year":2009,"publication_date":"2009-02-20","ids":{"openalex":"https://openalex.org/W3000294563","doi":"https://doi.org/10.37236/114","mag":"3000294563"},"language":"en","primary_location":{"id":"doi:10.37236/114","is_oa":true,"landing_page_url":"https://doi.org/10.37236/114","pdf_url":"https://www.combinatorics.org/ojs/index.php/eljc/article/download/v16i1r25/pdf","source":{"id":"https://openalex.org/S38448739","display_name":"The Electronic Journal of Combinatorics","issn_l":"1077-8926","issn":["1077-8926","1097-1440"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310317970","host_organization_name":"Electronic Journal of Combinatorics","host_organization_lineage":["https://openalex.org/P4310317970"],"host_organization_lineage_names":["Electronic Journal of Combinatorics"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"The Electronic Journal of Combinatorics","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","doaj"],"open_access":{"is_oa":true,"oa_status":"diamond","oa_url":"https://www.combinatorics.org/ojs/index.php/eljc/article/download/v16i1r25/pdf","any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5074643979","display_name":"Alexander L. Churchill","orcid":null},"institutions":[{"id":"https://openalex.org/I97018004","display_name":"Stanford University","ror":"https://ror.org/00f54p054","country_code":"US","type":"education","lineage":["https://openalex.org/I97018004"]}],"countries":["US"],"is_corresponding":true,"raw_author_name":"Alexander L. Churchill","raw_affiliation_strings":["Student Stanford University, California, USA"],"affiliations":[{"raw_affiliation_string":"Student Stanford University, California, USA","institution_ids":["https://openalex.org/I97018004"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":["https://openalex.org/A5074643979"],"corresponding_institution_ids":["https://openalex.org/I97018004"],"apc_list":null,"apc_paid":null,"fwci":0.3535,"has_fulltext":true,"cited_by_count":5,"citation_normalized_percentile":{"value":0.67805009,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":90,"max":96},"biblio":{"volume":"16","issue":"1","first_page":null,"last_page":null},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11567","display_name":"semigroups and automata theory","score":0.9994999766349792,"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":0.9994999766349792,"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/T11130","display_name":"Coding theory and cryptography","score":0.9994000196456909,"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/T11797","display_name":"graph theory and CDMA systems","score":0.9988999962806702,"subfield":{"id":"https://openalex.org/subfields/2208","display_name":"Electrical and Electronic Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/alphabet","display_name":"Alphabet","score":0.8142685294151306},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.6685684323310852},{"id":"https://openalex.org/keywords/combinatorics","display_name":"Combinatorics","score":0.5633078217506409},{"id":"https://openalex.org/keywords/class","display_name":"Class (philosophy)","score":0.5550470948219299},{"id":"https://openalex.org/keywords/word","display_name":"Word (group theory)","score":0.5509839653968811},{"id":"https://openalex.org/keywords/coding","display_name":"Coding (social sciences)","score":0.5229609608650208},{"id":"https://openalex.org/keywords/coding-theory","display_name":"Coding theory","score":0.4724612236022949},{"id":"https://openalex.org/keywords/series","display_name":"Series (stratigraphy)","score":0.4248621463775635},{"id":"https://openalex.org/keywords/discrete-mathematics","display_name":"Discrete mathematics","score":0.4200456440448761},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.25109997391700745},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.10575872659683228},{"id":"https://openalex.org/keywords/linguistics","display_name":"Linguistics","score":0.08293101191520691},{"id":"https://openalex.org/keywords/statistics","display_name":"Statistics","score":0.05721324682235718}],"concepts":[{"id":"https://openalex.org/C112876837","wikidata":"https://www.wikidata.org/wiki/Q837518","display_name":"Alphabet","level":2,"score":0.8142685294151306},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.6685684323310852},{"id":"https://openalex.org/C114614502","wikidata":"https://www.wikidata.org/wiki/Q76592","display_name":"Combinatorics","level":1,"score":0.5633078217506409},{"id":"https://openalex.org/C2777212361","wikidata":"https://www.wikidata.org/wiki/Q5127848","display_name":"Class (philosophy)","level":2,"score":0.5550470948219299},{"id":"https://openalex.org/C90805587","wikidata":"https://www.wikidata.org/wiki/Q10944557","display_name":"Word (group theory)","level":2,"score":0.5509839653968811},{"id":"https://openalex.org/C179518139","wikidata":"https://www.wikidata.org/wiki/Q5140297","display_name":"Coding (social sciences)","level":2,"score":0.5229609608650208},{"id":"https://openalex.org/C113709454","wikidata":"https://www.wikidata.org/wiki/Q602136","display_name":"Coding theory","level":2,"score":0.4724612236022949},{"id":"https://openalex.org/C143724316","wikidata":"https://www.wikidata.org/wiki/Q312468","display_name":"Series (stratigraphy)","level":2,"score":0.4248621463775635},{"id":"https://openalex.org/C118615104","wikidata":"https://www.wikidata.org/wiki/Q121416","display_name":"Discrete mathematics","level":1,"score":0.4200456440448761},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.25109997391700745},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.10575872659683228},{"id":"https://openalex.org/C41895202","wikidata":"https://www.wikidata.org/wiki/Q8162","display_name":"Linguistics","level":1,"score":0.08293101191520691},{"id":"https://openalex.org/C105795698","wikidata":"https://www.wikidata.org/wiki/Q12483","display_name":"Statistics","level":1,"score":0.05721324682235718},{"id":"https://openalex.org/C151730666","wikidata":"https://www.wikidata.org/wiki/Q7205","display_name":"Paleontology","level":1,"score":0.0},{"id":"https://openalex.org/C86803240","wikidata":"https://www.wikidata.org/wiki/Q420","display_name":"Biology","level":0,"score":0.0},{"id":"https://openalex.org/C138885662","wikidata":"https://www.wikidata.org/wiki/Q5891","display_name":"Philosophy","level":0,"score":0.0},{"id":"https://openalex.org/C2524010","wikidata":"https://www.wikidata.org/wiki/Q8087","display_name":"Geometry","level":1,"score":0.0}],"mesh":[],"locations_count":2,"locations":[{"id":"doi:10.37236/114","is_oa":true,"landing_page_url":"https://doi.org/10.37236/114","pdf_url":"https://www.combinatorics.org/ojs/index.php/eljc/article/download/v16i1r25/pdf","source":{"id":"https://openalex.org/S38448739","display_name":"The Electronic Journal of Combinatorics","issn_l":"1077-8926","issn":["1077-8926","1097-1440"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310317970","host_organization_name":"Electronic Journal of Combinatorics","host_organization_lineage":["https://openalex.org/P4310317970"],"host_organization_lineage_names":["Electronic Journal of Combinatorics"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"The Electronic Journal of Combinatorics","raw_type":"journal-article"},{"id":"pmh:oai:CiteSeerX.psu:10.1.1.214.548","is_oa":false,"landing_page_url":"http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.214.548","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"http://www.combinatorics.org/Volume_16/PDF/v16i1r25.pdf","raw_type":"text"}],"best_oa_location":{"id":"doi:10.37236/114","is_oa":true,"landing_page_url":"https://doi.org/10.37236/114","pdf_url":"https://www.combinatorics.org/ojs/index.php/eljc/article/download/v16i1r25/pdf","source":{"id":"https://openalex.org/S38448739","display_name":"The Electronic Journal of Combinatorics","issn_l":"1077-8926","issn":["1077-8926","1097-1440"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310317970","host_organization_name":"Electronic Journal of Combinatorics","host_organization_lineage":["https://openalex.org/P4310317970"],"host_organization_lineage_names":["Electronic Journal of Combinatorics"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"The Electronic Journal of Combinatorics","raw_type":"journal-article"},"sustainable_development_goals":[{"id":"https://metadata.un.org/sdg/4","score":0.5,"display_name":"Quality Education"}],"awards":[],"funders":[{"id":"https://openalex.org/F4320309369","display_name":"Massachusetts Institute of Technology","ror":"https://ror.org/042nb2s44"}],"has_content":{"grobid_xml":true,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W3000294563.pdf","grobid_xml":"https://content.openalex.org/works/W3000294563.grobid-xml"},"referenced_works_count":10,"referenced_works":["https://openalex.org/W1975076306","https://openalex.org/W1982078145","https://openalex.org/W2049481245","https://openalex.org/W2064609917","https://openalex.org/W2091716984","https://openalex.org/W2094071249","https://openalex.org/W2323136735","https://openalex.org/W6662815138","https://openalex.org/W6666699454","https://openalex.org/W6700543191"],"related_works":["https://openalex.org/W2074481494","https://openalex.org/W2808006995","https://openalex.org/W4250156143","https://openalex.org/W4247156967","https://openalex.org/W582626623","https://openalex.org/W4240940369","https://openalex.org/W4298850403","https://openalex.org/W2808496111","https://openalex.org/W3088566498","https://openalex.org/W2952313416"],"abstract_inverted_index":{"A":[0],"significant":[1],"sector":[2],"of":[3,8,21,39,61,66,108],"coding":[4],"theory":[5],"is":[6,31],"that":[7,11],"comma-free":[9,40,55,86,89],"coding;":[10],"is,":[12],"codes":[13,87,90],"which":[14,42],"can":[15,43],"be":[16],"received":[17],"without":[18],"the":[19,36,64,104,117],"need":[20],"a":[22,45,49,53,59,68],"letter":[23],"used":[24],"for":[25,98,116],"word":[26,72],"separation.":[27],"The":[28],"major":[29],"difficulty":[30],"in":[32,91],"finding":[33],"bounds":[34,62,97],"on":[35,63],"maximum":[37],"number":[38],"words":[41],"inhabit":[44],"dictionary.":[46],"We":[47,77],"introduce":[48,79],"new":[50,81],"class":[51],"called":[52],"self-reflective":[54],"dictionary":[56,69],"and":[57,74,88,94,106],"prove":[58,95],"series":[60],"size":[65],"such":[67,83],"based":[70],"upon":[71],"length":[73],"alphabet":[75],"size.":[76],"also":[78],"other":[80],"classes":[82],"as":[84],"self-swappable":[85],"q":[92],"dimensions":[93],"preliminary":[96],"these":[99,110],"classes.":[100],"Finally,":[101],"we":[102],"discuss":[103],"implications":[105,115],"applications":[107],"combining":[109],"original":[111],"concepts,":[112],"including":[113],"their":[114],"NP-complete":[118],"Post":[119],"Correspondence":[120],"Problem.":[121]},"counts_by_year":[{"year":2024,"cited_by_count":1},{"year":2016,"cited_by_count":1},{"year":2015,"cited_by_count":2}],"updated_date":"2026-04-05T17:49:38.594831","created_date":"2025-10-10T00:00:00"}
