{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T11:22:40Z","timestamp":1784200960679,"version":"3.55.0"},"reference-count":44,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2020,8,21]],"date-time":"2020-08-21T00:00:00Z","timestamp":1597968000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004916","name":"Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado do Amazonas","doi-asserted-by":"publisher","award":["PAPAC program EDITAL N\u00b0 005\/2019"],"award-info":[{"award-number":["PAPAC program EDITAL N\u00b0 005\/2019"]}],"id":[{"id":"10.13039\/501100004916","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004916","name":"Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado do Amazonas","doi-asserted-by":"publisher","award":["POSGRAD program EDITAL N\u00b0 003\/2019"],"award-info":[{"award-number":["POSGRAD program EDITAL N\u00b0 003\/2019"]}],"id":[{"id":"10.13039\/501100004916","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002322","name":"Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior","doi-asserted-by":"publisher","award":["FAPEAM\/PPP program, (EDITAL 004\/2017)"],"award-info":[{"award-number":["FAPEAM\/PPP program, (EDITAL 004\/2017)"]}],"id":[{"id":"10.13039\/501100002322","id-type":"DOI","asserted-by":"publisher"}]},{"name":"CT-INFRA","award":["FAPEAM\/PPP program, (EDITAL 004\/2017)"],"award-info":[{"award-number":["FAPEAM\/PPP program, (EDITAL 004\/2017)"]}]},{"name":"MCT\/CNPQ","award":["PPP program, (EDITAL 004\/2017)"],"award-info":[{"award-number":["PPP program, (EDITAL 004\/2017)"]}]},{"name":"SECTI\/AM","award":["PPP program, (EDITAL 004\/2017)"],"award-info":[{"award-number":["PPP program, (EDITAL 004\/2017)"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Considering the variation of the received signal strength indicator (RSSI) in wireless networks, the objective of this study is to investigate and propose a method of indoor localization in order to improve the accuracy of localization that is compromised by RSSI variation. For this, quartile analysis is used for data pre-processing and the k-nearest neighbors (kNN) classifier is used for localization. In addition to the tests in a real environment, simulations were performed, varying many parameters related to the proposed method and the environment. In the real environment with reference points of 1.284 density per unit area (RPs\/m2), the method presents zero-mean error in the localization in test points (TPs) coinciding with the RPs. In the simulated environment with a density of 0.327 RPs\/m2, a mean error of 0.490 m for the localization of random TPs was achieved. These results are important contributions and allow us to conclude that the method is promising for locating objects in indoor environments.<\/jats:p>","DOI":"10.3390\/s20174714","type":"journal-article","created":{"date-parts":[[2020,8,21]],"date-time":"2020-08-21T09:21:51Z","timestamp":1598001711000},"page":"4714","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["QA-kNN: Indoor Localization Based on Quartile Analysis and the kNN Classifier for Wireless Networks"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5717-4018","authenticated-orcid":false,"given":"David","family":"Ferreira","sequence":"first","affiliation":[{"name":"Department of Electronics and Computing Engineering (DTEC)\u2014Electrical Engineering Graduate Program (PPGEE), Federal University of Amazonas, Manaus, AM 69067-005, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7389-6245","authenticated-orcid":false,"given":"Richard","family":"Souza","sequence":"additional","affiliation":[{"name":"Department of Electrical and Electronics Engineering, Federal University of Santa Catarina, Florian\u00f3polis, SC 88040-900, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Celso","family":"Carvalho","sequence":"additional","affiliation":[{"name":"Department of Electronics and Computing Engineering (DTEC)\u2014Electrical Engineering Graduate Program (PPGEE), Federal University of Amazonas, Manaus, AM 69067-005, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,8,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Jabraeil, M.A.J., Bahrami, B., Heidari, A., Allahverdizadeh, P., and Norouzi, F. 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