{"id":"https://openalex.org/W2978755170","doi":"https://doi.org/10.3390/e21100963","title":"Texture Classification Using Spectral Entropy of Acoustic Signal Generated by a Human Echolocator","display_name":"Texture Classification Using Spectral Entropy of Acoustic Signal Generated by a Human Echolocator","publication_year":2019,"publication_date":"2019-10-02","ids":{"openalex":"https://openalex.org/W2978755170","doi":"https://doi.org/10.3390/e21100963","mag":"2978755170"},"language":"en","primary_location":{"id":"doi:10.3390/e21100963","is_oa":true,"landing_page_url":"https://doi.org/10.3390/e21100963","pdf_url":"https://www.mdpi.com/1099-4300/21/10/963/pdf?version=1571105512","source":{"id":"https://openalex.org/S195231649","display_name":"Entropy","issn_l":"1099-4300","issn":["1099-4300"],"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":"Entropy","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","doaj"],"open_access":{"is_oa":true,"oa_status":"gold","oa_url":"https://www.mdpi.com/1099-4300/21/10/963/pdf?version=1571105512","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5039097633","display_name":"Raja Syamsul Azmir Raja Abdullah","orcid":"https://orcid.org/0000-0002-9375-2038"},"institutions":[{"id":"https://openalex.org/I130343225","display_name":"Universiti Putra Malaysia","ror":"https://ror.org/02e91jd64","country_code":"MY","type":"education","lineage":["https://openalex.org/I130343225"]}],"countries":["MY"],"is_corresponding":true,"raw_author_name":"Raja Syamsul Azmir Raja Abdullah","raw_affiliation_strings":["Wireless and Photonic Network Research Centre (WiPNET), Faculty of Engineering, University Putra Malaysia (UPM), Serdang 43400, Malaysia"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Wireless and Photonic Network Research Centre (WiPNET), Faculty of Engineering, University Putra Malaysia (UPM), Serdang 43400, Malaysia","institution_ids":["https://openalex.org/I130343225"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5088098057","display_name":"Nur Luqman Saleh","orcid":"https://orcid.org/0000-0002-6067-3421"},"institutions":[{"id":"https://openalex.org/I130343225","display_name":"Universiti Putra Malaysia","ror":"https://ror.org/02e91jd64","country_code":"MY","type":"education","lineage":["https://openalex.org/I130343225"]}],"countries":["MY"],"is_corresponding":false,"raw_author_name":"Nur Luqman Saleh","raw_affiliation_strings":["Wireless and Photonic Network Research Centre (WiPNET), Faculty of Engineering, University Putra Malaysia (UPM), Serdang 43400, Malaysia"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Wireless and Photonic Network Research Centre (WiPNET), Faculty of Engineering, University Putra Malaysia (UPM), Serdang 43400, Malaysia","institution_ids":["https://openalex.org/I130343225"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5112473223","display_name":"Sharifah Mumtazah Syed Abdul Rahman","orcid":null},"institutions":[{"id":"https://openalex.org/I130343225","display_name":"Universiti Putra Malaysia","ror":"https://ror.org/02e91jd64","country_code":"MY","type":"education","lineage":["https://openalex.org/I130343225"]}],"countries":["MY"],"is_corresponding":false,"raw_author_name":"Sharifah Mumtazah Syed Abdul Rahman","raw_affiliation_strings":["Wireless and Photonic Network Research Centre (WiPNET), Faculty of Engineering, University Putra Malaysia (UPM), Serdang 43400, Malaysia"],"raw_orcid":"https://orcid.org/0000-0002-5498-8451","affiliations":[{"raw_affiliation_string":"Wireless and Photonic Network Research Centre (WiPNET), Faculty of Engineering, University Putra Malaysia (UPM), Serdang 43400, Malaysia","institution_ids":["https://openalex.org/I130343225"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5076814052","display_name":"Nur Syazmira Zamri","orcid":null},"institutions":[{"id":"https://openalex.org/I130343225","display_name":"Universiti Putra Malaysia","ror":"https://ror.org/02e91jd64","country_code":"MY","type":"education","lineage":["https://openalex.org/I130343225"]}],"countries":["MY"],"is_corresponding":false,"raw_author_name":"Nur Syazmira Zamri","raw_affiliation_strings":["Wireless and Photonic Network Research Centre (WiPNET), Faculty of Engineering, University Putra Malaysia (UPM), Serdang 43400, Malaysia"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Wireless and Photonic Network Research Centre (WiPNET), Faculty of Engineering, University Putra Malaysia (UPM), Serdang 43400, Malaysia","institution_ids":["https://openalex.org/I130343225"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5056088451","display_name":"Nur Emileen Abd Rashid","orcid":"https://orcid.org/0000-0002-6384-4134"},"institutions":[{"id":"https://openalex.org/I82724352","display_name":"Universiti Teknologi MARA","ror":"https://ror.org/05n8tts92","country_code":"MY","type":"education","lineage":["https://openalex.org/I82724352"]}],"countries":["MY"],"is_corresponding":false,"raw_author_name":"Nur Emileen Abdul Rashid","raw_affiliation_strings":["Microwave Research Institute, UniversitiTeknologi MARA (UiTM), Shah Alam 40450, Selangor, Malaysia"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Microwave Research Institute, UniversitiTeknologi MARA (UiTM), Shah Alam 40450, Selangor, Malaysia","institution_ids":["https://openalex.org/I82724352"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":2,"corresponding_author_ids":["https://openalex.org/A5039097633"],"corresponding_institution_ids":["https://openalex.org/I130343225"],"apc_list":{"value":2000,"currency":"CHF","value_usd":2227},"apc_paid":{"value":2000,"currency":"CHF","value_usd":2227},"fwci":0.1544,"has_fulltext":false,"cited_by_count":6,"citation_normalized_percentile":{"value":0.50852273,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":89,"max":97},"biblio":{"volume":"21","issue":"10","first_page":"963","last_page":"963"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11309","display_name":"Music and Audio Processing","score":0.9997000098228455,"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"}},"topics":[{"id":"https://openalex.org/T11309","display_name":"Music and Audio Processing","score":0.9997000098228455,"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"}},{"id":"https://openalex.org/T10860","display_name":"Speech and Audio Processing","score":0.9995999932289124,"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"}},{"id":"https://openalex.org/T10201","display_name":"Speech Recognition and Synthesis","score":0.9883999824523926,"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/pattern-recognition","display_name":"Pattern recognition (psychology)","score":0.5996366739273071},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.5878620147705078},{"id":"https://openalex.org/keywords/entropy","display_name":"Entropy (arrow of time)","score":0.5450832843780518},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.5370745658874512},{"id":"https://openalex.org/keywords/cluster-analysis","display_name":"Cluster analysis","score":0.5146263837814331},{"id":"https://openalex.org/keywords/speech-recognition","display_name":"Speech recognition","score":0.47171658277511597},{"id":"https://openalex.org/keywords/acoustics","display_name":"Acoustics","score":0.4486069679260254},{"id":"https://openalex.org/keywords/classifier","display_name":"Classifier (UML)","score":0.44733676314353943},{"id":"https://openalex.org/keywords/human-echolocation","display_name":"Human echolocation","score":0.43846794962882996},{"id":"https://openalex.org/keywords/signal-processing","display_name":"Signal processing","score":0.436227023601532},{"id":"https://openalex.org/keywords/physics","display_name":"Physics","score":0.23041662573814392},{"id":"https://openalex.org/keywords/telecommunications","display_name":"Telecommunications","score":0.09496888518333435}],"concepts":[{"id":"https://openalex.org/C153180895","wikidata":"https://www.wikidata.org/wiki/Q7148389","display_name":"Pattern recognition (psychology)","level":2,"score":0.5996366739273071},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.5878620147705078},{"id":"https://openalex.org/C106301342","wikidata":"https://www.wikidata.org/wiki/Q4117933","display_name":"Entropy (arrow of time)","level":2,"score":0.5450832843780518},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.5370745658874512},{"id":"https://openalex.org/C73555534","wikidata":"https://www.wikidata.org/wiki/Q622825","display_name":"Cluster analysis","level":2,"score":0.5146263837814331},{"id":"https://openalex.org/C28490314","wikidata":"https://www.wikidata.org/wiki/Q189436","display_name":"Speech recognition","level":1,"score":0.47171658277511597},{"id":"https://openalex.org/C24890656","wikidata":"https://www.wikidata.org/wiki/Q82811","display_name":"Acoustics","level":1,"score":0.4486069679260254},{"id":"https://openalex.org/C95623464","wikidata":"https://www.wikidata.org/wiki/Q1096149","display_name":"Classifier (UML)","level":2,"score":0.44733676314353943},{"id":"https://openalex.org/C167954536","wikidata":"https://www.wikidata.org/wiki/Q1920844","display_name":"Human echolocation","level":2,"score":0.43846794962882996},{"id":"https://openalex.org/C104267543","wikidata":"https://www.wikidata.org/wiki/Q208163","display_name":"Signal processing","level":3,"score":0.436227023601532},{"id":"https://openalex.org/C121332964","wikidata":"https://www.wikidata.org/wiki/Q413","display_name":"Physics","level":0,"score":0.23041662573814392},{"id":"https://openalex.org/C76155785","wikidata":"https://www.wikidata.org/wiki/Q418","display_name":"Telecommunications","level":1,"score":0.09496888518333435},{"id":"https://openalex.org/C554190296","wikidata":"https://www.wikidata.org/wiki/Q47528","display_name":"Radar","level":2,"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":5,"locations":[{"id":"doi:10.3390/e21100963","is_oa":true,"landing_page_url":"https://doi.org/10.3390/e21100963","pdf_url":"https://www.mdpi.com/1099-4300/21/10/963/pdf?version=1571105512","source":{"id":"https://openalex.org/S195231649","display_name":"Entropy","issn_l":"1099-4300","issn":["1099-4300"],"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":"Entropy","raw_type":"journal-article"},{"id":"pmh:oai:psasir.upm.edu.my:82160","is_oa":false,"landing_page_url":null,"pdf_url":null,"source":{"id":"https://openalex.org/S4377196260","display_name":"Universiti Putra Malaysia Institutional Repository (Universiti Putra Malaysia)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I130343225","host_organization_name":"Universiti Putra Malaysia","host_organization_lineage":["https://openalex.org/I130343225"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"acceptedVersion","is_accepted":true,"is_published":false,"raw_source_name":null,"raw_type":"Article"},{"id":"pmh:oai:doaj.org/article:b21bf5ee8c5c4abe888884dc3d19394a","is_oa":true,"landing_page_url":"https://doaj.org/article/b21bf5ee8c5c4abe888884dc3d19394a","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":"Entropy, Vol 21, Iss 10, p 963 (2019)","raw_type":"article"},{"id":"pmh:oai:mdpi.com:/1099-4300/21/10/963/","is_oa":true,"landing_page_url":"http://dx.doi.org/10.3390/e21100963","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":"Entropy","raw_type":"Text"},{"id":"pmh:oai:pubmedcentral.nih.gov:7514294","is_oa":true,"landing_page_url":"https://www.ncbi.nlm.nih.gov/pmc/articles/7514294","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":"Entropy (Basel)","raw_type":"Text"}],"best_oa_location":{"id":"doi:10.3390/e21100963","is_oa":true,"landing_page_url":"https://doi.org/10.3390/e21100963","pdf_url":"https://www.mdpi.com/1099-4300/21/10/963/pdf?version=1571105512","source":{"id":"https://openalex.org/S195231649","display_name":"Entropy","issn_l":"1099-4300","issn":["1099-4300"],"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":"Entropy","raw_type":"journal-article"},"sustainable_development_goals":[{"display_name":"Quality Education","id":"https://metadata.un.org/sdg/4","score":0.6100000143051147}],"awards":[],"funders":[{"id":"https://openalex.org/F4320321709","display_name":"Ministry of Higher Education, Malaysia","ror":"https://ror.org/05mcs2t73"},{"id":"https://openalex.org/F4320322714","display_name":"Universiti Putra Malaysia","ror":"https://ror.org/02e91jd64"}],"has_content":{"grobid_xml":false,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W2978755170.pdf"},"referenced_works_count":45,"referenced_works":["https://openalex.org/W1976238604","https://openalex.org/W1979531689","https://openalex.org/W1992033104","https://openalex.org/W2002551291","https://openalex.org/W2006741511","https://openalex.org/W2024823681","https://openalex.org/W2031559519","https://openalex.org/W2038803784","https://openalex.org/W2057498692","https://openalex.org/W2059947199","https://openalex.org/W2074561068","https://openalex.org/W2088012703","https://openalex.org/W2111719469","https://openalex.org/W2130640900","https://openalex.org/W2137343183","https://openalex.org/W2146590246","https://openalex.org/W2154252319","https://openalex.org/W2156481234","https://openalex.org/W2163630896","https://openalex.org/W2327402526","https://openalex.org/W2495709992","https://openalex.org/W2526498414","https://openalex.org/W2551959666","https://openalex.org/W2560339084","https://openalex.org/W2593235593","https://openalex.org/W2752275306","https://openalex.org/W2754197908","https://openalex.org/W2768731046","https://openalex.org/W2769402512","https://openalex.org/W2782354506","https://openalex.org/W2783994778","https://openalex.org/W2796574722","https://openalex.org/W2800558590","https://openalex.org/W2805033630","https://openalex.org/W2883624990","https://openalex.org/W2905248597","https://openalex.org/W2942662356","https://openalex.org/W2942861350","https://openalex.org/W2948131761","https://openalex.org/W2953717604","https://openalex.org/W2961492042","https://openalex.org/W2980008364","https://openalex.org/W4233893061","https://openalex.org/W6750891216","https://openalex.org/W6769332530"],"related_works":["https://openalex.org/W2060524054","https://openalex.org/W2042021875","https://openalex.org/W2385428986","https://openalex.org/W2103359691","https://openalex.org/W3149153319","https://openalex.org/W4312304807","https://openalex.org/W3134982391","https://openalex.org/W2514349685","https://openalex.org/W2077239111","https://openalex.org/W2913025661"],"abstract_inverted_index":{"Human":[0],"echolocation":[1,59,137],"is":[2,30,231],"a":[3,10,46,50,56,77,108,135],"biological":[4],"process":[5,114],"wherein":[6],"the":[7,15,18,24,36,62,65,72,103,152,160,171,175,180,184,190,202,208,214,223],"human":[8,47,58,136,161,234],"emits":[9],"punctuated":[11],"acoustic":[12,28,43],"signal,":[13],"and":[14,75,121,195],"ear":[16],"analyzes":[17],"echo":[19,73,110,126],"in":[20,55,102,145,213],"order":[21],"to":[22,68,80],"perceive":[23],"surroundings.":[25],"The":[26,90,112,124,220],"peculiar":[27],"signal":[29,44,54,74,173],"normally":[31],"produced":[32],"by":[33],"clicking":[34],"inside":[35],"mouth.":[37],"This":[38],"paper":[39,66],"utilized":[40],"this":[41],"unique":[42],"from":[45,71,84,98,151,170,183],"echolocator":[48],"as":[49,179],"source":[51],"of":[52,64,107,174,204,222],"transmitted":[53],"synthetic":[57,141],"technique.":[60],"Thus,":[61],"aim":[63],"was":[67,92,155],"extract":[69],"information":[70],"develop":[76],"classification":[78,113,191,215],"scheme":[79,91],"identify":[81],"signals":[82,127],"reflected":[83,109,125],"different":[85],"textures":[86],"at":[87],"various":[88],"distance.":[89],"based":[93],"on":[94],"spectral":[95,167,210,229],"entropy":[96,150,181,211,230],"extracted":[97,149,209],"Mel-scale":[99,185],"filtering":[100,186],"output":[101],"Mel-frequency":[104],"cepstrum":[105],"coefficient":[106],"signal.":[111],"involved":[115],"data":[116,142],"mining,":[117],"features":[118,168],"extraction,":[119],"clustering,":[120],"classifier":[122,224],"validation.":[123],"were":[128,177,199,217],"obtained":[129,182],"via":[130],"an":[131],"experimental":[132],"setup":[133],"resembling":[134],"scenario,":[138],"configured":[139],"for":[140,159,233],"collection.":[143],"Unlike":[144],"typical":[146],"speech":[147],"signals,":[148],"formant":[153],"characteristics":[154],"likely":[156],"not":[157],"visible":[158],"mouth-click":[162,176],"signals.":[163],"Instead,":[164],"multiple":[165],"peak":[166],"derived":[169],"synthesis":[172],"assumed":[178],"output.":[187],"To":[188],"realize":[189],"process,":[192],"K-means":[193],"clustering":[194],"K-nearest":[196],"neighbor":[197],"processes":[198],"employed.":[200],"Moreover,":[201],"impacts":[203],"sound":[205],"propagation":[206],"toward":[207],"used":[212],"outcome":[216],"also":[218],"investigated.":[219],"outcomes":[221],"performance":[225],"herein":[226],"indicated":[227],"that":[228],"essential":[232],"echolocation.":[235]},"counts_by_year":[{"year":2026,"cited_by_count":1},{"year":2024,"cited_by_count":3},{"year":2023,"cited_by_count":1},{"year":2022,"cited_by_count":1}],"updated_date":"2026-07-30T17:31:21.811387","created_date":"2025-10-10T00:00:00"}