{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2024,4,16]],"date-time":"2024-04-16T15:13:43Z","timestamp":1713280423216},"reference-count":0,"publisher":"Copernicus GmbH","license":[{"start":{"date-parts":[[2021,6,4]],"date-time":"2021-06-04T00:00:00Z","timestamp":1622764800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["AGILE GIScience Ser."],"abstract":"<jats:p>Abstract. Data produced by social networks may contain weak signals of possible epidemic outbreaks. In this paper, we focus on Twitter data during the waiting period before the appearance of COVID-19 first cases outside China. Among the huge flow of tweets that reflects a global growing concern in all countries, we propose to analyze such data with an adaptation of the TF-IDF measure. It allows the users to extract the discriminant vocabularies used across time and space. The results are then discussed to show how the specific spatio-temporal anchoring of the extracted terms make it possible to follow the crisis dynamics on different scales of time and space.  \n                    <\/jats:p>","DOI":"10.5194\/agile-giss-2-2-2021","type":"journal-article","created":{"date-parts":[[2021,6,4]],"date-time":"2021-06-04T12:25:45Z","timestamp":1622809545000},"page":"1-8","source":"Crossref","is-referenced-by-count":1,"title":["H-TFIDF: What makes areas specific over time in the massive flow of tweets related to the covid pandemic?"],"prefix":"10.5194","volume":"2","author":[{"given":"R\u00e9my","family":"Decoupes","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rodrique","family":"Kafando","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mathieu","family":"Roche","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maguelonne","family":"Teisseire","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"3145","published-online":{"date-parts":[[2021,6,4]]},"container-title":["AGILE: GIScience Series"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/agile-giss.copernicus.org\/articles\/2\/2\/2021\/agile-giss-2-2-2021.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,6,7]],"date-time":"2021-06-07T12:06:24Z","timestamp":1623067584000},"score":1,"resource":{"primary":{"URL":"https:\/\/agile-giss.copernicus.org\/articles\/2\/2\/2021\/"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,6,4]]},"references-count":0,"URL":"https:\/\/doi.org\/10.5194\/agile-giss-2-2-2021","relation":{},"ISSN":["2700-8150"],"issn-type":[{"value":"2700-8150","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,6,4]]}}}