Saturday, April 12, 2014

AAG and Twitter

After spending a rather enjoyable few days at the Association of American Geographers (AAG) annual meeting in Tampa where there were some great talks on agent-based modeling, GIS and many other topics which I find interesting, along with catching up with some old friends and meeting new ones, its now time to head back up North. 

However, before jumping on the plane, I thought it would be intersing to look at the twitter traffic of the event (especially how there so many talks on using social media for geographical research). That being said, before showing the Twitter networks associated with the conference, one issue that was common among the conversion outside of the sessions was the lack of wifi access at the conference which accounts for small numbers of tweets durring the events but also one could argue people were more interested in the talks than that of tweeting. With that being said, within this analysis we show below we collected data using the #aag2014 and the @theAAG to explore the Twitter conversation.

The image below shows the # hashtag network from the conference with the biggest cluster being #aag2014 and associated words (click here to see a high solution image)


In the next image we removed the #aag2014 to only show the details of the network within this cluster. After removing the #aag2014 we re-ran the clustering on this network. The graph below shows the biggest clusters (with 3 or more nodes) within the #aag2014 group. Nicely outlined are the discussion topics (e.g. gender, sexuality, intimacy, climate, geoweb). Click here to see a higher resolution image.


Moving away from the hashtags and looking at the retweet network we were surprised to see that the AAG's account wasn't more active (click here to see a higher resolution image).


Also we are currently working on a spatial-temporal slider to look at the conversion over time. Below is a sneak peak from one moment in time. This will be soon coming to the Geosocial Gauge website. 



Wednesday, April 09, 2014

An Agent-based Model for the Spread and Containment of Tuberculosis

Over the last few months we have been working on developing a agent-based model which explores the spread and containment of tuberculosis. Today is the first time that we show the model to a academic audience at the AAG Annual meeting. To give a sense of our research, below is the abstract:
Tuberculosis (TB) is a global problem and especially in developing countries. After human immunodeficiency virus (HIV) it is the most common form of death from an infectious disease. However, it is still unknown exactly how it spreads within a population. A geographic explicit agent-based model, with humans as agents, was created and applied to study the TB problem. Specifically the model was developed to see what epidemiological dynamics may occur, and what could be learned about the spreading of the disease. The model was developed in MASON and utilizes the GeoMason GIS extension. A Susceptible-Exposed-Infectious-Recovered (SEIR) submodel was created to model TB progression and linked to daily human activities. The slum of Kibera, Kenya (the largest urban slum in Africa, and an area where TB and HIV is particularly rampant) was chosen as a test-case. Detailed geospatial and demographic information from Kibera was used for the instantiation of the models spatial environment and demographic properties of the agents. Preliminary results obtained from standard model runs show that TB epidemics progress in staircase patterns of emergence and stabilization. Furthermore, it was found that TB was creating hotspots, or pockets of dense disease concentration, from where it was spreading. The results and lessons gleaned from the model can be easily incorporated into current health policies to mitigate TB's negative impact. Furthermore, the research shows the potential of ABMs in investigating infectious diseases.
Susceptible-Exposed-Infectious-Recovered (SEIR) submodel


To give a sense of what the model looks like below we show the full model running with 250,000 agents on the slum of Kibera, Kenya.


In the next movie we show the model running with only 50,000 agents but with a zoomed in section of the Kibera Slum. In this movie, you can see the agents going about their daily activities and how some become infected with TB.


This work would not of been possible without the work of my co-author Parth Chopra and the Thomas Jefferson High School for Science and Technology Mentorship Program.

Thursday, April 03, 2014

Social Media and the Emergence of Open-Source Geospatial Intelligence

Recently the USGIF published a book entitled "Human Geography: Socio-Cultural Dynamics and Global Security" in which we have a chapter called "Social Media and the Emergence of Open-Source Geospatial Intelligence". This book has been some  time in the making. We blogged about our contribution in  2012. But its finally its out! Below is the abstract for our chapter:

The emergence of social media has provided the public with an effective and irrepressible real-time mechanism to broadcast information. The great popularity of platforms such as twitter and YouTube, and the substantial amount of content that is communicated through them are making social media an essential component of open-source intelligence. The information communicated through such feeds conveys the interests and opinions of individuals, and reveals links and the complex structure of social networks. However, this information is only partially exploited if one does not consider its geographical aspect. Indeed, social media feeds more often than not have some sort of geographic content, as they may communicate the location from where a particular report is contributed, the geolocation of an image, or they may refer to a specific sociocultural hotspot. By harvesting this geographic content from social media feeds we can transfer the extracted knowledge from the amorphous cyberspace to the geographic space, and gain a unique understanding of the human lansdscape, its structure and organization, and its evolution over time. This newfound opportunity signals the emergence of open-source geospatial intelligence, whereby social media contributions can be analyzed and mined to gain unparalleled situational awareness. In this paper we showcase a number of sample applications that highlight the capabilities of harvesting geospatial intelligence from social media feeds, focusing particularly on twitter as a representative data source. 

Geolocated pairs of tweeters and retweeters in Tokyo at the time immediately following the Sendai earthquake

Full Reference: 
Stefanidis, A., Crooks, A.T., Radzikowski, J., Croitoru, A. and Rice, M. (2014), Social Media and the Emergence of Open-Source Geospatial Intelligence, in Murdock, D.G., Tomes, R. and Tucker, C. (eds.), Human Geography: Socio-Cultural Dynamics and Global Security, US Geospatial Intelligence Foundation (USGIF), Herndon, VA, pp. 109-123. (pdf)

Multi-Agent Systems for Urban Planning

Recently we contributed a chapter to "Technologies for Urban and Spatial Planning: Virtual Cities and Territories" which aims to quote from the preference:  
"(i) to contribute to the dissemination of the recent research and development of the use of information and communication technologies (ICT) in urban and spatial planning, trying to demonstrate their usability in planning processes through the presentation of relevant case studies, framed by their underlying theory; (ii) to give additional evidence to the fact that ICT are the privileged means to produce virtual cities and territories; and (iii) to make available, from a pedagogical standpoint, a group of illustrative reviews of the scientific production made by both academics and practitioners in the field."
The book has 11 chapters which are grouped in several themes:
"first group focuses on the discussion over the use of ICT in spatial planning; the second group of contributions deals with urban modelling and simulation; the third group focuses on the use of different sensors to acquire information and model spatial processes; the fourth group focuses on the use of data to create more capable visualization tools; and the fifth group is about the use of virtual models to simulate real environments and plan and manage other aspects of the built environment such as energy."
Our chapter is entitled "Multi-agent Systems for Urban Planning" fits into the second group with respect to urban modeling and simulation. We present a detailed overview about the theory and the development of multi-agent systems (MAS) in spatial planning, focusing on how MAS can lead to insights into urban problems and aid urban planning fostering a bottom up approach to spatial planning. The abstract is as follows:
Cities provide homes for over half of the world's population, and this proportion is expected to increase throughout the next century. The growth of cities raises many questions and challenges for urban planning including which cities and regions are most likely to grow, what the pattern of urban growth will be, and how the existing infrastructure will cope with such growth. One way to explore these types of questions is through the use of multi-agent systems (MAS) that are capable of modeling how individuals interact and how structures emerge through such interactions, in terms of both the social and physical environment of cities. Within this chapter, the authors focus on how MAS can lead to insights into urban problems and aid urban planning from the bottom up. They review MAS models that explore the growth of cities and regions, models that explore land-use patterns resulting from such growth along with the rise of slums. Furthermore, the authors demonstrate how MAS models can be used to model transportation and the changing demographics of cities. Through these examples the authors also demonstrate how this style of modeling can give insights into such issues that cannot be gleamed from other modeling methodologies. The chapter concludes with challenges and future research directions of MAS models with respect to capturing the dynamics of human behavior in urban planning.

Full Reference:
Crooks, A.T., Patel, A. and Wise, S. (2014), Multi-agent Systems for Urban Planning, in Pinto, N.N., Tenedório, J. Antunes A. P. and Roca, J. (eds.), Technologies for Urban and Spatial Planning: Virtual Cities and Territories, IGI Global, Hershey, PA, pp. 29-56. (pdf)

Friday, March 21, 2014

AAG 2014: Geosimulation Models Sessions

If you going to this years AAG, you might be interested in our Geosimulation Models sessions which will take place on Wednesday the 9th of April from 10am.

Session Description: Since the publication of Geosimulation in 2004, the use of Agent-based Modeling (ABM) and Cellular Automata (CA) under the umbrella of Geosimulation models within geographical systems have started to mature as methodologies to explore a wide range of geographical and more broadly social sciences problems facing society. The aim of these sessions is to bring together researchers utilizing geosimulation techniques (and associated methodologies) to discuss topics relating to: theory, technical issues and applications domains of ABM and CA within geographical systems.



10:00 AM to 11:40,  Room 39, TCC, Fourth Floor , Chair: Suzana Dragicevic



12.40PM to 2.20PM, Room 39, TCC, Fourth Floor, Chair: Paul Torrens



2:40 PM to 4:20 PM in Room 39, TCC, Fourth Floor, Chair: Paul Torrens

Siyu Fan and Yichun Xie

We would also like to thank the following AAG specialty groups for sponsoring our sessions: Spatial Analysis and Modeling Specialty GroupCyberinfrastructure Specialty Group and the Geographic Information Science and Systems Specialty Group