{"id":"https://openalex.org/W1995937139","doi":"https://doi.org/10.1109/tip.2015.2405346","title":"Human Facial Expression Recognition Using Stepwise Linear Discriminant Analysis and Hidden Conditional Random Fields","display_name":"Human Facial Expression Recognition Using Stepwise Linear Discriminant Analysis and Hidden Conditional Random Fields","publication_year":2015,"publication_date":"2015-02-24","ids":{"openalex":"https://openalex.org/W1995937139","doi":"https://doi.org/10.1109/tip.2015.2405346","mag":"1995937139","pmid":"https://pubmed.ncbi.nlm.nih.gov/25856814"},"language":"en","primary_location":{"id":"doi:10.1109/tip.2015.2405346","is_oa":false,"landing_page_url":"https://doi.org/10.1109/tip.2015.2405346","pdf_url":null,"source":{"id":"https://openalex.org/S4210173141","display_name":"IEEE Transactions on Image Processing","issn_l":"1057-7149","issn":["1057-7149","1941-0042"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Transactions on Image Processing","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","pubmed"],"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/A5041711498","display_name":"Muhammad Hameed Siddiqi","orcid":"https://orcid.org/0000-0002-4370-8012"},"institutions":[{"id":"https://openalex.org/I35928602","display_name":"Kyung Hee University","ror":"https://ror.org/01zqcg218","country_code":"KR","type":"education","lineage":["https://openalex.org/I35928602"]}],"countries":["KR"],"is_corresponding":true,"raw_author_name":"Muhammad Hameed Siddiqi","raw_affiliation_strings":["Department of Computer Engineering, Kyung Hee University, Suwon, Korea","Dept. of Computer Engineering, Kyung Hee University, Suwon, Korea"],"affiliations":[{"raw_affiliation_string":"Department of Computer Engineering, Kyung Hee University, Suwon, Korea","institution_ids":["https://openalex.org/I35928602"]},{"raw_affiliation_string":"Dept. of Computer Engineering, Kyung Hee University, Suwon, Korea","institution_ids":["https://openalex.org/I35928602"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5063257512","display_name":"Rahman Ali","orcid":"https://orcid.org/0000-0002-9171-8573"},"institutions":[{"id":"https://openalex.org/I35928602","display_name":"Kyung Hee University","ror":"https://ror.org/01zqcg218","country_code":"KR","type":"education","lineage":["https://openalex.org/I35928602"]}],"countries":["KR"],"is_corresponding":false,"raw_author_name":"Rahman Ali","raw_affiliation_strings":["Department of Computer Engineering, Kyung Hee University, Suwon, Korea","Dept. of Computer Engineering, Kyung Hee University, Suwon, Korea"],"affiliations":[{"raw_affiliation_string":"Department of Computer Engineering, Kyung Hee University, Suwon, Korea","institution_ids":["https://openalex.org/I35928602"]},{"raw_affiliation_string":"Dept. of Computer Engineering, Kyung Hee University, Suwon, Korea","institution_ids":["https://openalex.org/I35928602"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5070522496","display_name":"Adil Khan","orcid":"https://orcid.org/0000-0003-2220-8518"},"institutions":[{"id":"https://openalex.org/I4210116741","display_name":"Innopolis University","ror":"https://ror.org/02b7jh107","country_code":"RU","type":"education","lineage":["https://openalex.org/I4210116741"]}],"countries":["RU"],"is_corresponding":false,"raw_author_name":"Adil Mehmood Khan","raw_affiliation_strings":["Department of Computer Science, Innopolis University, Kazan, Russia"],"affiliations":[{"raw_affiliation_string":"Department of Computer Science, Innopolis University, Kazan, Russia","institution_ids":["https://openalex.org/I4210116741"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5016740388","display_name":"Young-Tack Park","orcid":null},"institutions":[{"id":"https://openalex.org/I141371507","display_name":"Soongsil University","ror":"https://ror.org/017xnm587","country_code":"KR","type":"education","lineage":["https://openalex.org/I141371507"]}],"countries":["KR"],"is_corresponding":false,"raw_author_name":"Young-Tack Park","raw_affiliation_strings":["School of Information Technology, Soongsil University, Seoul, Korea"],"affiliations":[{"raw_affiliation_string":"School of Information Technology, Soongsil University, Seoul, Korea","institution_ids":["https://openalex.org/I141371507"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5101882040","display_name":"Sungyoung Lee","orcid":"https://orcid.org/0000-0002-5962-1587"},"institutions":[{"id":"https://openalex.org/I35928602","display_name":"Kyung Hee University","ror":"https://ror.org/01zqcg218","country_code":"KR","type":"education","lineage":["https://openalex.org/I35928602"]}],"countries":["KR"],"is_corresponding":false,"raw_author_name":"Sungyoung Lee","raw_affiliation_strings":["Department of Computer Engineering, Kyung Hee University, Suwon, Korea","Dept. of Computer Engineering, Kyung Hee University, Suwon, Korea"],"affiliations":[{"raw_affiliation_string":"Department of Computer Engineering, Kyung Hee University, Suwon, Korea","institution_ids":["https://openalex.org/I35928602"]},{"raw_affiliation_string":"Dept. of Computer Engineering, Kyung Hee University, Suwon, Korea","institution_ids":["https://openalex.org/I35928602"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":5,"corresponding_author_ids":["https://openalex.org/A5041711498"],"corresponding_institution_ids":["https://openalex.org/I35928602"],"apc_list":null,"apc_paid":null,"fwci":11.598,"has_fulltext":false,"cited_by_count":179,"citation_normalized_percentile":{"value":0.98986634,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":96,"max":100},"biblio":{"volume":"24","issue":"4","first_page":"1386","last_page":"1398"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10057","display_name":"Face and Expression Recognition","score":0.9988999962806702,"subfield":{"id":"https://openalex.org/subfields/1707","display_name":"Computer Vision and Pattern Recognition"},"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/T10057","display_name":"Face and Expression Recognition","score":0.9988999962806702,"subfield":{"id":"https://openalex.org/subfields/1707","display_name":"Computer Vision and Pattern Recognition"},"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/T10667","display_name":"Emotion and Mood Recognition","score":0.9919999837875366,"subfield":{"id":"https://openalex.org/subfields/3205","display_name":"Experimental and Cognitive Psychology"},"field":{"id":"https://openalex.org/fields/32","display_name":"Psychology"},"domain":{"id":"https://openalex.org/domains/2","display_name":"Social Sciences"}},{"id":"https://openalex.org/T13731","display_name":"Advanced Computing and Algorithms","score":0.9804999828338623,"subfield":{"id":"https://openalex.org/subfields/3322","display_name":"Urban Studies"},"field":{"id":"https://openalex.org/fields/33","display_name":"Social Sciences"},"domain":{"id":"https://openalex.org/domains/2","display_name":"Social Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/pattern-recognition","display_name":"Pattern recognition (psychology)","score":0.7915675640106201},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.7266349792480469},{"id":"https://openalex.org/keywords/linear-discriminant-analysis","display_name":"Linear discriminant analysis","score":0.6592264771461487},{"id":"https://openalex.org/keywords/feature-extraction","display_name":"Feature extraction","score":0.5606687068939209},{"id":"https://openalex.org/keywords/conditional-random-field","display_name":"Conditional random field","score":0.5332773327827454},{"id":"https://openalex.org/keywords/expression","display_name":"Expression (computer science)","score":0.5074824690818787},{"id":"https://openalex.org/keywords/facial-expression","display_name":"Facial expression","score":0.5070040225982666},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.47806575894355774},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.47049570083618164},{"id":"https://openalex.org/keywords/gaussian","display_name":"Gaussian","score":0.4186203181743622},{"id":"https://openalex.org/keywords/feature","display_name":"Feature (linguistics)","score":0.41061896085739136}],"concepts":[{"id":"https://openalex.org/C153180895","wikidata":"https://www.wikidata.org/wiki/Q7148389","display_name":"Pattern recognition (psychology)","level":2,"score":0.7915675640106201},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.7266349792480469},{"id":"https://openalex.org/C69738355","wikidata":"https://www.wikidata.org/wiki/Q1228929","display_name":"Linear discriminant analysis","level":2,"score":0.6592264771461487},{"id":"https://openalex.org/C52622490","wikidata":"https://www.wikidata.org/wiki/Q1026626","display_name":"Feature extraction","level":2,"score":0.5606687068939209},{"id":"https://openalex.org/C152565575","wikidata":"https://www.wikidata.org/wiki/Q1124538","display_name":"Conditional random field","level":2,"score":0.5332773327827454},{"id":"https://openalex.org/C90559484","wikidata":"https://www.wikidata.org/wiki/Q778379","display_name":"Expression (computer science)","level":2,"score":0.5074824690818787},{"id":"https://openalex.org/C195704467","wikidata":"https://www.wikidata.org/wiki/Q327968","display_name":"Facial expression","level":2,"score":0.5070040225982666},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.47806575894355774},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.47049570083618164},{"id":"https://openalex.org/C163716315","wikidata":"https://www.wikidata.org/wiki/Q901177","display_name":"Gaussian","level":2,"score":0.4186203181743622},{"id":"https://openalex.org/C2776401178","wikidata":"https://www.wikidata.org/wiki/Q12050496","display_name":"Feature (linguistics)","level":2,"score":0.41061896085739136},{"id":"https://openalex.org/C41895202","wikidata":"https://www.wikidata.org/wiki/Q8162","display_name":"Linguistics","level":1,"score":0.0},{"id":"https://openalex.org/C121332964","wikidata":"https://www.wikidata.org/wiki/Q413","display_name":"Physics","level":0,"score":0.0},{"id":"https://openalex.org/C62520636","wikidata":"https://www.wikidata.org/wiki/Q944","display_name":"Quantum mechanics","level":1,"score":0.0},{"id":"https://openalex.org/C199360897","wikidata":"https://www.wikidata.org/wiki/Q9143","display_name":"Programming language","level":1,"score":0.0},{"id":"https://openalex.org/C138885662","wikidata":"https://www.wikidata.org/wiki/Q5891","display_name":"Philosophy","level":0,"score":0.0}],"mesh":[{"descriptor_ui":"D000293","descriptor_name":"Adolescent","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D000293","descriptor_name":"Adolescent","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D000293","descriptor_name":"Adolescent","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D000328","descriptor_name":"Adult","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D000328","descriptor_name":"Adult","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D000328","descriptor_name":"Adult","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D000465","descriptor_name":"Algorithms","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D000465","descriptor_name":"Algorithms","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D000465","descriptor_name":"Algorithms","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D005145","descriptor_name":"Face","qualifier_ui":"Q000033","qualifier_name":"anatomy & histology","is_major_topic":false},{"descriptor_ui":"D005145","descriptor_name":"Face","qualifier_ui":"Q000033","qualifier_name":"anatomy & histology","is_major_topic":false},{"descriptor_ui":"D005145","descriptor_name":"Face","qualifier_ui":"Q000033","qualifier_name":"anatomy & histology","is_major_topic":false},{"descriptor_ui":"D005149","descriptor_name":"Facial Expression","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D005149","descriptor_name":"Facial Expression","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D005149","descriptor_name":"Facial Expression","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D005260","descriptor_name":"Female","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D005260","descriptor_name":"Female","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D005260","descriptor_name":"Female","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D006801","descriptor_name":"Humans","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D006801","descriptor_name":"Humans","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D006801","descriptor_name":"Humans","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D007089","descriptor_name":"Image Enhancement","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D007089","descriptor_name":"Image Enhancement","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D007089","descriptor_name":"Image Enhancement","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D007090","descriptor_name":"Image Interpretation, Computer-Assisted","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D007090","descriptor_name":"Image Interpretation, Computer-Assisted","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D007090","descriptor_name":"Image Interpretation, Computer-Assisted","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D008297","descriptor_name":"Male","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D008297","descriptor_name":"Male","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D008297","descriptor_name":"Male","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D008390","descriptor_name":"Markov Chains","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D008390","descriptor_name":"Markov Chains","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D008390","descriptor_name":"Markov Chains","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D010363","descriptor_name":"Pattern Recognition, Automated","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D010363","descriptor_name":"Pattern Recognition, Automated","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D010363","descriptor_name":"Pattern Recognition, Automated","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D010781","descriptor_name":"Photography","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D010781","descriptor_name":"Photography","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D010781","descriptor_name":"Photography","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D012680","descriptor_name":"Sensitivity and Specificity","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D012680","descriptor_name":"Sensitivity and Specificity","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D012680","descriptor_name":"Sensitivity and Specificity","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D015203","descriptor_name":"Reproducibility of Results","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D015203","descriptor_name":"Reproducibility of Results","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D015203","descriptor_name":"Reproducibility of Results","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D016002","descriptor_name":"Discriminant Analysis","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D016002","descriptor_name":"Discriminant Analysis","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D016002","descriptor_name":"Discriminant Analysis","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D055815","descriptor_name":"Young Adult","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D055815","descriptor_name":"Young Adult","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D055815","descriptor_name":"Young Adult","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D056667","descriptor_name":"Biometric Identification","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D056667","descriptor_name":"Biometric Identification","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D056667","descriptor_name":"Biometric Identification","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false}],"locations_count":2,"locations":[{"id":"doi:10.1109/tip.2015.2405346","is_oa":false,"landing_page_url":"https://doi.org/10.1109/tip.2015.2405346","pdf_url":null,"source":{"id":"https://openalex.org/S4210173141","display_name":"IEEE Transactions on Image Processing","issn_l":"1057-7149","issn":["1057-7149","1941-0042"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Transactions on Image Processing","raw_type":"journal-article"},{"id":"pmid:25856814","is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/25856814","pdf_url":null,"source":{"id":"https://openalex.org/S4306525036","display_name":"PubMed","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I1299303238","host_organization_name":"National Institutes of Health","host_organization_lineage":["https://openalex.org/I1299303238"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE transactions on image processing : a publication of the IEEE Signal Processing Society","raw_type":null}],"best_oa_location":null,"sustainable_development_goals":[{"display_name":"Reduced inequalities","id":"https://metadata.un.org/sdg/10","score":0.7300000190734863}],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":91,"referenced_works":["https://openalex.org/W94763889","https://openalex.org/W1483662103","https://openalex.org/W1522488816","https://openalex.org/W1556905813","https://openalex.org/W1560641285","https://openalex.org/W1575540224","https://openalex.org/W1640878532","https://openalex.org/W1964762821","https://openalex.org/W1969030392","https://openalex.org/W1970809932","https://openalex.org/W1975226595","https://openalex.org/W1985641745","https://openalex.org/W1996958556","https://openalex.org/W2002822271","https://openalex.org/W2007431552","https://openalex.org/W2009659028","https://openalex.org/W2022214793","https://openalex.org/W2041657594","https://openalex.org/W2052024152","https://openalex.org/W2053437444","https://openalex.org/W2058098602","https://openalex.org/W2060844334","https://openalex.org/W2064828821","https://openalex.org/W2067893425","https://openalex.org/W2071653495","https://openalex.org/W2074867602","https://openalex.org/W2088575594","https://openalex.org/W2091550557","https://openalex.org/W2096071754","https://openalex.org/W2097844709","https://openalex.org/W2101534792","https://openalex.org/W2101811166","https://openalex.org/W2102570318","https://openalex.org/W2103943262","https://openalex.org/W2104773058","https://openalex.org/W2106115875","https://openalex.org/W2107488200","https://openalex.org/W2108403479","https://openalex.org/W2117704033","https://openalex.org/W2121394390","https://openalex.org/W2121647436","https://openalex.org/W2125874614","https://openalex.org/W2127196145","https://openalex.org/W2127483610","https://openalex.org/W2130179707","https://openalex.org/W2133651588","https://openalex.org/W2136171036","https://openalex.org/W2137338002","https://openalex.org/W2141567247","https://openalex.org/W2145310492","https://openalex.org/W2145511413","https://openalex.org/W2147667726","https://openalex.org/W2147880316","https://openalex.org/W2150796457","https://openalex.org/W2155655319","https://openalex.org/W2156615793","https://openalex.org/W2161634108","https://openalex.org/W2166732168","https://openalex.org/W2167103782","https://openalex.org/W2168854967","https://openalex.org/W2169493788","https://openalex.org/W2185938598","https://openalex.org/W2231160293","https://openalex.org/W2236025256","https://openalex.org/W2293200953","https://openalex.org/W2305348436","https://openalex.org/W2314479002","https://openalex.org/W2320389993","https://openalex.org/W2402955625","https://openalex.org/W2475432418","https://openalex.org/W2725374515","https://openalex.org/W2963695034","https://openalex.org/W3034751874","https://openalex.org/W3144058330","https://openalex.org/W4210993929","https://openalex.org/W4238539449","https://openalex.org/W4239085738","https://openalex.org/W6637022928","https://openalex.org/W6672481139","https://openalex.org/W6674626981","https://openalex.org/W6675927160","https://openalex.org/W6678906477","https://openalex.org/W6682082992","https://openalex.org/W6686523527","https://openalex.org/W6689898316","https://openalex.org/W6689971360","https://openalex.org/W6697973474","https://openalex.org/W6721461273","https://openalex.org/W6740801418","https://openalex.org/W6778907217","https://openalex.org/W6990575327"],"related_works":["https://openalex.org/W2380927352","https://openalex.org/W1968332688","https://openalex.org/W2146076056","https://openalex.org/W2811390910","https://openalex.org/W2134472250","https://openalex.org/W203536286","https://openalex.org/W3165453100","https://openalex.org/W2546942002","https://openalex.org/W2022684485","https://openalex.org/W1497005071"],"abstract_inverted_index":{"This":[0],"paper":[1],"introduces":[2],"an":[3,113],"accurate":[4],"and":[5,47,122,153,173],"robust":[6],"facial":[7],"expression":[8,34,55,129,140],"recognition":[9,92,184],"(FER)":[10],"system.":[11],"For":[12,57],"feature":[13],"extraction,":[14],"the":[15,29,33,37,43,49,59,87,107,118,128,133,136,139,142,164,187,194,207],"proposed":[16,188],"FER":[17,189,209],"system":[18,88],"employs":[19,89],"stepwise":[20],"linear":[21],"discriminant":[22],"analysis":[23],"(SWLDA).":[24],"SWLDA":[25,121,152],"focuses":[26],"on":[27,104],"selecting":[28],"localized":[30],"features":[31],"from":[32],"frames":[35],"using":[36,76,147],"partial":[38],"F-test":[39],"values,":[40],"thereby":[41],"reducing":[42],"within":[44,141],"class":[45],"variance":[46,52],"increasing":[48],"low":[50],"between":[51],"among":[53],"different":[54,196],"classes.":[56],"recognition,":[58,116],"hidden":[60],"conditional":[61],"random":[62],"fields":[63],"(HCRFs)":[64],"model":[65],"is":[66,69,145,200],"utilized.":[67],"HCRF":[68,123],"capable":[70],"of":[71,79,106,151,176],"approximating":[72],"a":[73,77,90,148,174,201],"complex":[74],"distribution":[75],"mixture":[78],"Gaussian":[80],"density":[81],"functions.":[82],"To":[83],"achieve":[84],"optimum":[85],"results,":[86],"hierarchical":[91],"strategy.":[93],"Under":[94],"these":[95],"settings,":[96],"expressions":[97],"are":[98,124],"divided":[99],"into":[100],"three":[101],"categories":[102],"based":[103],"parts":[105],"face":[108],"that":[109,158],"contribute":[110],"most":[111],"toward":[112],"expression.":[114],"During":[115],"at":[117,132],"first":[119],"level,":[120,135],"employed":[125],"to":[126,162,206],"recognize":[127],"category;":[130],"whereas,":[131],"second":[134],"label":[137],"for":[138,157,186],"recognized":[143],"category":[144],"determined":[146],"separate":[149],"set":[150],"HCRF,":[154],"trained":[155],"just":[156],"category.":[159],"In":[160],"order":[161],"validate":[163],"system,":[165],"four":[166,177,195],"publicly":[167],"available":[168],"data":[169,197],"sets":[170],"were":[171,179],"used,":[172],"total":[175],"experiments":[178],"performed.":[180],"The":[181],"weighted":[182],"average":[183],"rate":[185],"approach":[190],"was":[191],"96.37%":[192],"across":[193],"sets,":[198],"which":[199],"significant":[202],"improvement":[203],"in":[204],"contrast":[205],"existing":[208],"methods.":[210]},"counts_by_year":[{"year":2025,"cited_by_count":4},{"year":2024,"cited_by_count":3},{"year":2023,"cited_by_count":8},{"year":2022,"cited_by_count":22},{"year":2021,"cited_by_count":21},{"year":2020,"cited_by_count":22},{"year":2019,"cited_by_count":36},{"year":2018,"cited_by_count":24},{"year":2017,"cited_by_count":17},{"year":2016,"cited_by_count":19},{"year":2015,"cited_by_count":3}],"updated_date":"2025-11-06T03:46:38.306776","created_date":"2025-10-10T00:00:00"}
