@article{Santa2019,
title = {A Statistical Approach for Studying the Spatio-Temporal Distribution of Geolocated Tweets in Urban Environments},
author = {Fernando Santa and Roberto Henriques and Joaquín Torres-Sospedra and Edzer Pebesma},
doi = {10.3390/su11030595},
year = {2019},
date = {2019-03-13},
journal = {Sustainability },
volume = {11},
number = {3},
pages = {595},
abstract = {An in-depth descriptive approach to the dynamics of the urban population is fundamental as a first step towards promoting effective planning and designing processes in cities. Understanding the behavioral aspects of human activities can contribute to their effective management and control. We present a framework, based on statistical methods, for studying the spatio-temporal distribution of geolocated tweets as a proxy for where and when people carry out their activities. We have evaluated our proposal by analyzing the distribution of collected geolocated tweets over a two-week period in the summer of 2017 in Lisbon, London, and Manhattan. Our proposal considers a negative binomial regression analysis for the time series of counts of tweets as a first step. We further estimate a functional principal component analysis of second-order summary statistics of the hourly spatial point patterns formed by the locations of the tweets. Finally, we find groups of hours with a similar spatial arrangement of places where humans develop their activities through hierarchical clustering over the principal scores. Social media events are found to show strong temporal trends such as seasonal variation due to the hour of the day and the day of the week in addition to autoregressive schemas. We have also identified spatio-temporal patterns of clustering, i.e., groups of hours of the day that present a similar spatial distribution of human activities.},
note = {IF:},
keywords = {GEO-C, Geo-social media, geolocation},
pubstate = {published},
tppubtype = {article}
}

@article{GranellCanut2016a,
title = {Beyond data collection: Objectives and methods of research using VGI and geo-social media for disaster management},
author = { Carlos Granell-Canut and Frank O. Ostermann},
url = {http://dx.doi.org/10.1016/j.compenvurbsys.2016.01.006},
doi = {10.1016/j.compenvurbsys.2016.01.006},
issn = {0198-9715},
year = {2016},
date = {2016-01-01},
journal = {Computers, Environment and Urban Systems},
pages = {in press},
publisher = {Elsevier Ltd},
abstract = {This paper investigates research using VGI and geo-social media in the disaster management context. Relying on the method of systematic mapping, it develops a classification schema that captures three levels of main category, focus, and intended use, and analyzes the relationships with the employed data sources and analysis methods. It focuses the scope to the pioneering field of disaster management, but the described approach and the developed classification schema are easily adaptable to different application domains or future developments. The results show that a hypothesized consolidation of research, characterized through the building of canonical bodies of knowledge and advanced application cases with refined methodology, has not yet happened. The majority of the studies investigate the challenges and potential solutions of data handling, with fewer studies focusing on socio-technological issues or advanced applications. This trend is currently showing no sign of change, highlighting that VGI research is still very much technology-driven as opposed to theory- or application-driven. From the results of the systematic mapping study, the authors formulate and discuss several research objectives for future work, which could lead to a stronger, more theory-driven treatment of the topic VGI in GIScience.},
note = {IF: 2.659 - 23/105 (Q1) Environmental Studies
2.659 - 13/79 (Q1) Geography
},
keywords = {crowdsourcing, data analysis methods, Disaster management, Geo-social media, RyC-Granell, Systematic mapping, VGI},
pubstate = {published},
tppubtype = {article}
}

@article{beltran_virtual_2011,
title = {A virtual globe tool for searching and visualizing geo-referenced media resources in social networks},
author = { Arturo Beltrán-Fonollosa and Carlos Abargues and Carlos Granell-Canut and Manuela Núñez-Redó and Laura Díaz-Sánchez and Joaquín Huerta-Guijarro},
url = {http://hdl.handle.net/10234/67339},
doi = {10.1007/s11042-012-1025-0},
issn = {1380-7501},
year = {2013},
date = {2013-05-01},
journal = {International Journal on Multimedia Tools and Applications},
volume = {64},
number = {1},
pages = {171--195},
abstract = {The current collaborative context and resource sharing that drives Web 2.0 is gaining importance within academia and industry, which is stimulating the development of new techniques for content retrieval, sharing and analysis over user-generated media content. This poses new challenges and research opportunities in spatial-based discovery media resources over varied sources, since location context is being increasingly supported in most of these social networks and services. In this paper, we present a virtual globe tool for searching and visualizing geo-referenced media resources. Our approach is based on the integration of search technologies, description languages for annotating collections of geo-referenced media resources and visualization techniques. The combination of these techniques is materialized in a virtual globe-based tool to facilitate searching and presentation of geo-referenced media resources available in different social networks.},
note = {IF: 1.058, Q2},
keywords = {data visualization, ESPANA-VIRTUAL, Geo-social media, georeferenced resources, virtual globes},
pubstate = {published},
tppubtype = {article}
}