Lacs
Flickr Africa: Examining Geo-Diversity in Large-Scale, Human-Centric Visual Data
Naggita, Keziah, LaChance, Julienne, Xiang, Alice
Biases in large-scale image datasets are known to influence the performance of computer vision models as a function of geographic context. To investigate the limitations of standard Internet data collection methods in low- and middle-income countries, we analyze human-centric image geo-diversity on a massive scale using geotagged Flickr images associated with each nation in Africa. We report the quantity and content of available data with comparisons to population-matched nations in Europe as well as the distribution of data according to fine-grained intra-national wealth estimates. Temporal analyses are performed at two-year intervals to expose emerging data trends. Furthermore, we present findings for an ``othering'' phenomenon as evidenced by a substantial number of images from Africa being taken by non-local photographers. The results of our study suggest that further work is required to capture image data representative of African people and their environments and, ultimately, to improve the applicability of computer vision models in a global context.
- Asia > Brunei (0.14)
- North America > Canada > Quebec > Montreal (0.06)
- Africa > Sierra Leone (0.06)
- (142 more...)
- Health & Medicine (0.92)
- Information Technology > Services (0.75)
- Government > Regional Government (0.46)
- Information Technology > Communications > Social Media (1.00)
- Information Technology > Artificial Intelligence > Vision (1.00)
Satellite-based high-resolution maps of cocoa planted area for C\^ote d'Ivoire and Ghana
Kalischek, Nikolai, Lang, Nico, Renier, Cécile, Daudt, Rodrigo Caye, Addoah, Thomas, Thompson, William, Blaser-Hart, Wilma J., Garrett, Rachael, Schindler, Konrad, Wegner, Jan D.
In both countries, cocoa is the primary perennial crop, providing income to almost two million farmers. Yet precise maps of cocoa planted area are missing, hindering accurate quantification of expansion in protected areas, production and yields, and limiting information available for improved sustainability governance. Here, we combine cocoa plantation data with publicly available satellite imagery in a deep learning framework and create high-resolution maps of cocoa plantations for both countries, validated in situ. Our results suggest that cocoa cultivation is an underlying driver of over 37 % and 13 % of forest loss in protected areas in Côte d'Ivoire and Ghana, respectively, and that official reports substantially underestimate the planted area, up to 40 % in Ghana. These maps serve as a crucial building block to advance understanding of conservation and economic development in cocoa producing regions.
- Africa > Ghana (0.86)
- Europe > Switzerland > Zürich > Zürich (0.14)
- Africa > West Africa (0.04)
- (13 more...)
- Law (0.93)
- Food & Agriculture > Agriculture (0.68)
- Energy > Renewable > Geothermal > Geothermal Energy Exploration and Development > Geophysical Analysis & Survey (0.35)
Country-scale Exploratory Analysis of Call Detail Records through the Lens of Data Grid Models
Guigourès, Romain, Gay, Dominique, Boullé, Marc, Clérot, Fabrice, Rossi, Fabrice
Call Detail Records (CDRs) are data recorded by telecommunications companies, consisting of basic informations related to several dimensions of the calls made through the network: the source, destination, date and time of calls. CDRs data analysis has received much attention in the recent years since it might reveal valuable information about human behavior. It has shown high added value in many application domains like e.g., communities analysis or network planning. In this paper, we suggest a generic methodology for summarizing information contained in CDRs data. The method is based on a parameter-free estimation of the joint distribution of the variables that describe the calls. We also suggest several well-founded criteria that allows one to browse the summary at various granularities and to explore the summary by means of insightful visualizations. The method handles network graph data, temporal sequence data as well as user mobility data stemming from original CDRs data. We show the relevance of our methodology for various case studies on real-world CDRs data from Ivory Coast.
- North America > Haiti (0.14)
- Africa > Côte d'Ivoire > Abidjan > Abidjan (0.06)
- Africa > Côte d'Ivoire > Vallee du Bandama > Bouake (0.05)
- (5 more...)
- Health & Medicine > Therapeutic Area > Infections and Infectious Diseases (0.68)
- Health & Medicine > Therapeutic Area > Immunology (0.68)
- Information Technology > Networks (0.48)
- Telecommunications > Networks (0.48)