{"id":"https://openalex.org/W4224303268","doi":"https://doi.org/10.3390/s22082833","title":"An Extended Kalman Filter for Magnetic Field SLAM Using Gaussian Process Regression","display_name":"An Extended Kalman Filter for Magnetic Field SLAM Using Gaussian Process Regression","publication_year":2022,"publication_date":"2022-04-07","ids":{"openalex":"https://openalex.org/W4224303268","doi":"https://doi.org/10.3390/s22082833","pmid":"https://pubmed.ncbi.nlm.nih.gov/35458817"},"language":"en","primary_location":{"id":"doi:10.3390/s22082833","is_oa":true,"landing_page_url":"https://doi.org/10.3390/s22082833","pdf_url":"https://www.mdpi.com/1424-8220/22/8/2833/pdf?version=1649411707","source":{"id":"https://openalex.org/S101949793","display_name":"Sensors","issn_l":"1424-8220","issn":["1424-8220"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310310987","host_organization_name":"Multidisciplinary Digital Publishing Institute","host_organization_lineage":["https://openalex.org/P4310310987"],"host_organization_lineage_names":["Multidisciplinary Digital Publishing Institute"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Sensors","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","doaj","pubmed"],"open_access":{"is_oa":true,"oa_status":"gold","oa_url":"https://www.mdpi.com/1424-8220/22/8/2833/pdf?version=1649411707","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5015489130","display_name":"Frida Viset","orcid":null},"institutions":[{"id":"https://openalex.org/I98358874","display_name":"Delft University of Technology","ror":"https://ror.org/02e2c7k09","country_code":"NL","type":"education","lineage":["https://openalex.org/I98358874"]}],"countries":["NL"],"is_corresponding":true,"raw_author_name":"Frida Viset","raw_affiliation_strings":["Delft Center for Systems and Control, Delft University of Technology, 2628 CD Delft, The Netherlands"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Delft Center for Systems and Control, Delft University of Technology, 2628 CD Delft, The Netherlands","institution_ids":["https://openalex.org/I98358874"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5038544106","display_name":"Rudy Helmons","orcid":"https://orcid.org/0000-0003-4929-5359"},"institutions":[{"id":"https://openalex.org/I98358874","display_name":"Delft University of Technology","ror":"https://ror.org/02e2c7k09","country_code":"NL","type":"education","lineage":["https://openalex.org/I98358874"]}],"countries":["NL"],"is_corresponding":false,"raw_author_name":"Rudy Helmons","raw_affiliation_strings":["Maritime and Transport Technology, Delft University of Technology, 2628 CD Delft, The Netherlands"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Maritime and Transport Technology, Delft University of Technology, 2628 CD Delft, The Netherlands","institution_ids":["https://openalex.org/I98358874"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5017416513","display_name":"Manon Kok","orcid":"https://orcid.org/0000-0002-2441-2240"},"institutions":[{"id":"https://openalex.org/I98358874","display_name":"Delft University of Technology","ror":"https://ror.org/02e2c7k09","country_code":"NL","type":"education","lineage":["https://openalex.org/I98358874"]}],"countries":["NL"],"is_corresponding":false,"raw_author_name":"Manon Kok","raw_affiliation_strings":["Delft Center for Systems and Control, Delft University of Technology, 2628 CD Delft, The Netherlands"],"raw_orcid":"https://orcid.org/0000-0002-2441-2240","affiliations":[{"raw_affiliation_string":"Delft Center for Systems and Control, Delft University of Technology, 2628 CD Delft, The Netherlands","institution_ids":["https://openalex.org/I98358874"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":3,"corresponding_author_ids":["https://openalex.org/A5015489130"],"corresponding_institution_ids":["https://openalex.org/I98358874"],"apc_list":{"value":2400,"currency":"CHF","value_usd":2598},"apc_paid":{"value":2400,"currency":"CHF","value_usd":2598},"fwci":33.0871,"has_fulltext":true,"cited_by_count":54,"citation_normalized_percentile":{"value":0.99623441,"is_in_top_1_percent":true,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":97,"max":100},"biblio":{"volume":"22","issue":"8","first_page":"2833","last_page":"2833"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10191","display_name":"Robotics and Sensor-Based Localization","score":0.9995999932289124,"subfield":{"id":"https://openalex.org/subfields/2202","display_name":"Aerospace Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10191","display_name":"Robotics and Sensor-Based Localization","score":0.9995999932289124,"subfield":{"id":"https://openalex.org/subfields/2202","display_name":"Aerospace Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10326","display_name":"Indoor and Outdoor Localization Technologies","score":0.9995999932289124,"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"}},{"id":"https://openalex.org/T10711","display_name":"Target Tracking and Data Fusion in Sensor Networks","score":0.9986000061035156,"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/kalman-filter","display_name":"Kalman filter","score":0.6881693005561829},{"id":"https://openalex.org/keywords/simultaneous-localization-and-mapping","display_name":"Simultaneous localization and mapping","score":0.6433870792388916},{"id":"https://openalex.org/keywords/odometry","display_name":"Odometry","score":0.624725341796875},{"id":"https://openalex.org/keywords/particle-filter","display_name":"Particle filter","score":0.556296706199646},{"id":"https://openalex.org/keywords/algorithm","display_name":"Algorithm","score":0.5514213442802429},{"id":"https://openalex.org/keywords/ensemble-kalman-filter","display_name":"Ensemble Kalman filter","score":0.540611743927002},{"id":"https://openalex.org/keywords/extended-kalman-filter","display_name":"Extended Kalman filter","score":0.5121464729309082},{"id":"https://openalex.org/keywords/magnetic-field","display_name":"Magnetic field","score":0.47875088453292847},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.45771896839141846},{"id":"https://openalex.org/keywords/field","display_name":"Field (mathematics)","score":0.4488641023635864},{"id":"https://openalex.org/keywords/computational-complexity-theory","display_name":"Computational complexity theory","score":0.44265368580818176},{"id":"https://openalex.org/keywords/gaussian-process","display_name":"Gaussian process","score":0.4373442530632019},{"id":"https://openalex.org/keywords/filter","display_name":"Filter (signal processing)","score":0.42261889576911926},{"id":"https://openalex.org/keywords/gaussian","display_name":"Gaussian","score":0.41997480392456055},{"id":"https://openalex.org/keywords/computer-vision","display_name":"Computer vision","score":0.39698418974876404},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.3808545470237732},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.3168003261089325},{"id":"https://openalex.org/keywords/physics","display_name":"Physics","score":0.2018434703350067},{"id":"https://openalex.org/keywords/mobile-robot","display_name":"Mobile robot","score":0.15422210097312927},{"id":"https://openalex.org/keywords/robot","display_name":"Robot","score":0.1149282455444336}],"concepts":[{"id":"https://openalex.org/C157286648","wikidata":"https://www.wikidata.org/wiki/Q846780","display_name":"Kalman filter","level":2,"score":0.6881693005561829},{"id":"https://openalex.org/C86369673","wikidata":"https://www.wikidata.org/wiki/Q1203659","display_name":"Simultaneous localization and mapping","level":4,"score":0.6433870792388916},{"id":"https://openalex.org/C49441653","wikidata":"https://www.wikidata.org/wiki/Q2014717","display_name":"Odometry","level":4,"score":0.624725341796875},{"id":"https://openalex.org/C52421305","wikidata":"https://www.wikidata.org/wiki/Q1151499","display_name":"Particle filter","level":3,"score":0.556296706199646},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.5514213442802429},{"id":"https://openalex.org/C79334102","wikidata":"https://www.wikidata.org/wiki/Q3072268","display_name":"Ensemble Kalman filter","level":4,"score":0.540611743927002},{"id":"https://openalex.org/C206833254","wikidata":"https://www.wikidata.org/wiki/Q5421817","display_name":"Extended Kalman filter","level":3,"score":0.5121464729309082},{"id":"https://openalex.org/C115260700","wikidata":"https://www.wikidata.org/wiki/Q11408","display_name":"Magnetic field","level":2,"score":0.47875088453292847},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.45771896839141846},{"id":"https://openalex.org/C9652623","wikidata":"https://www.wikidata.org/wiki/Q190109","display_name":"Field (mathematics)","level":2,"score":0.4488641023635864},{"id":"https://openalex.org/C179799912","wikidata":"https://www.wikidata.org/wiki/Q205084","display_name":"Computational complexity theory","level":2,"score":0.44265368580818176},{"id":"https://openalex.org/C61326573","wikidata":"https://www.wikidata.org/wiki/Q1496376","display_name":"Gaussian process","level":3,"score":0.4373442530632019},{"id":"https://openalex.org/C106131492","wikidata":"https://www.wikidata.org/wiki/Q3072260","display_name":"Filter (signal processing)","level":2,"score":0.42261889576911926},{"id":"https://openalex.org/C163716315","wikidata":"https://www.wikidata.org/wiki/Q901177","display_name":"Gaussian","level":2,"score":0.41997480392456055},{"id":"https://openalex.org/C31972630","wikidata":"https://www.wikidata.org/wiki/Q844240","display_name":"Computer vision","level":1,"score":0.39698418974876404},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.3808545470237732},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.3168003261089325},{"id":"https://openalex.org/C121332964","wikidata":"https://www.wikidata.org/wiki/Q413","display_name":"Physics","level":0,"score":0.2018434703350067},{"id":"https://openalex.org/C19966478","wikidata":"https://www.wikidata.org/wiki/Q4810574","display_name":"Mobile robot","level":3,"score":0.15422210097312927},{"id":"https://openalex.org/C90509273","wikidata":"https://www.wikidata.org/wiki/Q11012","display_name":"Robot","level":2,"score":0.1149282455444336},{"id":"https://openalex.org/C202444582","wikidata":"https://www.wikidata.org/wiki/Q837863","display_name":"Pure mathematics","level":1,"score":0.0},{"id":"https://openalex.org/C62520636","wikidata":"https://www.wikidata.org/wiki/Q944","display_name":"Quantum mechanics","level":1,"score":0.0}],"mesh":[],"locations_count":6,"locations":[{"id":"doi:10.3390/s22082833","is_oa":true,"landing_page_url":"https://doi.org/10.3390/s22082833","pdf_url":"https://www.mdpi.com/1424-8220/22/8/2833/pdf?version=1649411707","source":{"id":"https://openalex.org/S101949793","display_name":"Sensors","issn_l":"1424-8220","issn":["1424-8220"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310310987","host_organization_name":"Multidisciplinary Digital Publishing Institute","host_organization_lineage":["https://openalex.org/P4310310987"],"host_organization_lineage_names":["Multidisciplinary Digital Publishing Institute"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Sensors","raw_type":"journal-article"},{"id":"pmid:35458817","is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/35458817","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":"Sensors (Basel, Switzerland)","raw_type":null},{"id":"pmh:oai:doaj.org/article:c3d3013576c84e2d89e3589d935d9c34","is_oa":true,"landing_page_url":"https://doaj.org/article/c3d3013576c84e2d89e3589d935d9c34","pdf_url":null,"source":{"id":"https://openalex.org/S4306401280","display_name":"DOAJ (DOAJ: Directory of Open Access Journals)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by-sa","license_id":"https://openalex.org/licenses/cc-by-sa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"Sensors, Vol 22, Iss 8, p 2833 (2022)","raw_type":"article"},{"id":"pmh:oai:mdpi.com:/1424-8220/22/8/2833/","is_oa":true,"landing_page_url":"https://dx.doi.org/10.3390/s22082833","pdf_url":null,"source":{"id":"https://openalex.org/S4306400947","display_name":"MDPI (MDPI AG)","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I4210097602","host_organization_name":"Multidisciplinary Digital Publishing Institute (Switzerland)","host_organization_lineage":["https://openalex.org/I4210097602"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"Sensors; Volume 22; Issue 8; Pages: 2833","raw_type":"Text"},{"id":"pmh:oai:pubmedcentral.nih.gov:9025971","is_oa":true,"landing_page_url":"https://www.ncbi.nlm.nih.gov/pmc/articles/9025971","pdf_url":null,"source":{"id":"https://openalex.org/S2764455111","display_name":"PubMed Central","issn_l":null,"issn":null,"is_oa":true,"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":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"Sensors (Basel)","raw_type":"Text"},{"id":"pmh:oai:tudelft.nl:uuid:c61afc9a-6784-4fab-92d8-05af30bbe437","is_oa":true,"landing_page_url":"http://resolver.tudelft.nl/uuid:c61afc9a-6784-4fab-92d8-05af30bbe437","pdf_url":null,"source":{"id":"https://openalex.org/S4306400906","display_name":"Research Repository (Delft University of Technology)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I98358874","host_organization_name":"Delft University of Technology","host_organization_lineage":["https://openalex.org/I98358874"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"","raw_type":"journal article"}],"best_oa_location":{"id":"doi:10.3390/s22082833","is_oa":true,"landing_page_url":"https://doi.org/10.3390/s22082833","pdf_url":"https://www.mdpi.com/1424-8220/22/8/2833/pdf?version=1649411707","source":{"id":"https://openalex.org/S101949793","display_name":"Sensors","issn_l":"1424-8220","issn":["1424-8220"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310310987","host_organization_name":"Multidisciplinary Digital Publishing Institute","host_organization_lineage":["https://openalex.org/P4310310987"],"host_organization_lineage_names":["Multidisciplinary Digital Publishing Institute"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Sensors","raw_type":"journal-article"},"sustainable_development_goals":[{"score":0.5099999904632568,"display_name":"Life below water","id":"https://metadata.un.org/sdg/14"}],"awards":[{"id":"https://openalex.org/G297291188","display_name":null,"funder_award_id":"18213","funder_id":"https://openalex.org/F4320321800","funder_display_name":"Nederlandse Organisatie voor Wetenschappelijk Onderzoek"}],"funders":[{"id":"https://openalex.org/F4320321800","display_name":"Nederlandse Organisatie voor Wetenschappelijk Onderzoek","ror":"https://ror.org/04jsz6e67"},{"id":"https://openalex.org/F4320332054","display_name":"Researchlab Autonomous Shipping","ror":null}],"has_content":{"pdf":true,"grobid_xml":true},"content_urls":{"pdf":"https://content.openalex.org/works/W4224303268.pdf","grobid_xml":"https://content.openalex.org/works/W4224303268.grobid-xml"},"referenced_works_count":48,"referenced_works":["https://openalex.org/W157162768","https://openalex.org/W1665378886","https://openalex.org/W1948233104","https://openalex.org/W1967512722","https://openalex.org/W1967653388","https://openalex.org/W1968791640","https://openalex.org/W1969142081","https://openalex.org/W1971591628","https://openalex.org/W1978200836","https://openalex.org/W1986802839","https://openalex.org/W2018542777","https://openalex.org/W2037240009","https://openalex.org/W2043748895","https://openalex.org/W2056427752","https://openalex.org/W2067718279","https://openalex.org/W2077552673","https://openalex.org/W2082839938","https://openalex.org/W2083754578","https://openalex.org/W2085142065","https://openalex.org/W2085714719","https://openalex.org/W2090820607","https://openalex.org/W2093319033","https://openalex.org/W2100936798","https://openalex.org/W2105557362","https://openalex.org/W2134210795","https://openalex.org/W2149615975","https://openalex.org/W2153199180","https://openalex.org/W2160337655","https://openalex.org/W2315642557","https://openalex.org/W2461937780","https://openalex.org/W2489373752","https://openalex.org/W2568376783","https://openalex.org/W2589658453","https://openalex.org/W2602677875","https://openalex.org/W2769516531","https://openalex.org/W2781646407","https://openalex.org/W2964103707","https://openalex.org/W2964250998","https://openalex.org/W3004348324","https://openalex.org/W3103364054","https://openalex.org/W3104978629","https://openalex.org/W3109975069","https://openalex.org/W3124420883","https://openalex.org/W3215540479","https://openalex.org/W4205254640","https://openalex.org/W4251960031","https://openalex.org/W6676007211","https://openalex.org/W6677153691"],"related_works":["https://openalex.org/W2125871801","https://openalex.org/W2161240633","https://openalex.org/W4386821976","https://openalex.org/W2970345194","https://openalex.org/W4313288997","https://openalex.org/W2807473852","https://openalex.org/W1585960250","https://openalex.org/W2152464524","https://openalex.org/W2149015029","https://openalex.org/W2120540633"],"abstract_inverted_index":{"We":[0,175,210],"present":[1],"a":[2,39,50,77,96,160,166,194,203],"computationally":[3],"efficient":[4],"algorithm":[5,156,219],"for":[6,16,68,149,184,228],"using":[7,44,92],"variations":[8],"in":[9,19,49,206],"the":[10,32,56,59,88,107,114,122,127,141,177,180,213],"ambient":[11],"magnetic":[12,33,61,69,89,146,185,198,229],"field":[13,34,62,70,90,147,186,199,230],"to":[14,120,126,222],"compensate":[15],"position":[17],"drift":[18,214],"integrated":[20],"odometry":[21],"measurements":[22,200],"(dead-reckoning":[23],"estimates)":[24],"through":[25],"simultaneous":[26,150],"localization":[27,151],"and":[28,111,152,197],"mapping":[29],"(SLAM).":[30],"When":[31],"map":[35,91,148],"is":[36,106,113],"represented":[37],"with":[38,72,232],"reduced-rank":[40,73],"Gaussian":[41,123],"process":[42],"(GP)":[43],"Laplace":[45],"basis":[46,117],"functions":[47,118],"defined":[48],"cubical":[51],"domain,":[52],"analytic":[53],"expressions":[54],"of":[55,58,87,102,109,116,143,173,179,217],"gradient":[57],"learned":[60,145],"become":[63],"available.":[64],"An":[65],"existing":[66,128],"approach":[67],"SLAM":[71,187,231],"GP":[74],"regression":[75],"uses":[76],"Rao-Blackwellized":[78],"particle":[79,129],"filter":[80,138,183],"(RBPF).":[81],"For":[82],"each":[83,170],"incoming":[84],"measurement,":[85],"training":[86,159],"an":[93,135,189,207,233],"RBPF":[94],"has":[95,165,224],"computational":[97,167],"complexity":[98,168],"per":[99],"time":[100,171],"step":[101,172],"O(NpNm2),":[103],"where":[104],"Np":[105],"number":[108,115],"particles,":[110],"Nm":[112],"used":[119],"approximate":[121],"process.":[124],"Contrary":[125],"filter-based":[130],"approach,":[131],"we":[132],"propose":[133],"applying":[134],"extended":[136,181],"Kalman":[137,182],"based":[139],"on":[140,188],"gradients":[142],"our":[144,218],"mapping.":[153],"Our":[154],"proposed":[155],"only":[157],"requires":[158],"single":[161],"map.":[162],"It,":[163],"therefore,":[164],"at":[169],"O(Nm2).":[174],"demonstrate":[176],"workings":[178],"open-source":[190],"data":[191],"set":[192],"from":[193],"foot-mounted":[195],"sensor":[196],"collected":[201],"onboard":[202],"model":[204],"ship":[205],"indoor":[208],"pool.":[209],"observe":[211],"that":[212],"compensating":[215],"abilities":[216],"are":[220],"comparable":[221],"what":[223],"previously":[225],"been":[226],"demonstrated":[227],"RBPF.":[234]},"counts_by_year":[{"year":2026,"cited_by_count":2},{"year":2025,"cited_by_count":13},{"year":2024,"cited_by_count":16},{"year":2023,"cited_by_count":19},{"year":2022,"cited_by_count":4}],"updated_date":"2026-05-21T06:26:12.895304","created_date":"2025-10-10T00:00:00"}