Thursday, December 19, 2013

Agent-based Modeling and Theme Parks

Many of us have been to theme parks and waited in long lines to get on a particular attraction (ride), which to some extent reduces the overall experience of going to a theme park (i.e. no-one really likes waiting). The question is what causes these lines to build up and at what times of the day. Moreover, what can be done to reduce such lines thus increasing the visitors experience? These are perfect questions for an agent-based model to explore.  So while at the Winter Simulation Conference, in Washington DC the other week I happened to listen to a paper entitled "An Agent-Based Simulation Approach to Experience Management in Theme Parks" by a group of researchers from the Living Analytics Research Center (LARC) of the Singapore Management University.

GUI of the Smartphone App
In the paper, the authors explore how an agent-based model can be used to increase peoples experience within a theme park. What was particularly interesting about the paper is how the authors used a smartphone app to collect visitors behaviors while at a particular theme park over the course of a day. They then used this data in an agent-based model to understand how the crowds build up at specific attractions and explore various control polices which could potentially increase the visitors experience (i.e. reduce wait times). More information about the project can be found here and other work (publications) from LARC here.

Full reference to the paper:
Cheng, S.-F., Lin, L., Du, J., Lau, H.C. and Varakantham, P. (2013), 'An Agent-Based Simulation Approach to Experience Management in Theme Parks', in Pasupathy, R., Kim, S.-H., Tolk, A., Hill, R. and Kuhl, M.E. (eds.), Proceedings of the 2013 Winter Simulation Conference, Washington, DC, pp. 1527-1538.


Wednesday, December 11, 2013

Book review: A Framework for Geodesign:

Recently I had the pleasure of reading and reviewing the book entitled "A Framework for Geodesign: Changing Geography by Design" by Carl Steinitz. The full review can be found in Environment and Planning B. However, I thought I would share the review to readers of the blog (with some added images).

"People have designed and changed the geography of their landscapes for thousands of years, for the better or for the worse. But with more pressure being placed on the world’s resources, with increasing numbers of people, the question that we are now faced with is, what are the best sustainable design solutions to mitigate these challenges? For example, urban growth is inevitable given the increasing concentration of people living within in cities, and as a trend is expected to continue into the foreseeable future. The question that designers and planners are therefore faced with is what scenarios would lead to say the least amount of loss in biodiversity. But this is a multi-faceted problem ranging in scale from how do people build there homes, to where should new industry be located, or how should land be conserved etc? These are all questions involving spatial decision-making, and where geographic information systems can play an important role. Over the last forty years, geographic information systems (GIS) have increasingly been used to assist in such complex decisions, from modelling urban growth projections through to assessing the spread of pollution (see Longley et al., 2010 for a extensive list of applications). However, one of the original visions for GIS, which is often overlooked, is that of a tool for design (Goodchild, 2010).

In his book “A Framework for Geodesign: Changing Geography by Design” Karl Steinitz brings his vast experience as a landscape architect and planner to such an issue. For those not familiar to the term geodesign, Steinitz (2012) writes in his preference to the book that it “is an invented word, and a very useful term to describe an activity that is not the territory of any single design profession, geographic science or information technology” (p ix). More generally Steinitz (2012) frames geodesign as “the development and application of design-related processes intended to change the geographical study areas in which they are applied and realised” (p1). Or another way of putting it, the merging of geography and design through computers. This is reiterated later on by a quote from Michael Flaxman were he states “Geodesign is a design and planning method which tightly couples the creation of design proposals with impact simulations informed by geographic contexts, systems thinking, and digital technology” (Flaxman quoted in Steinitz, 2012 p 12).

Moreover, geodesign can be considered both as a verb and as a noun which Steinitz relates to design more generally (see Steinitz, 1995). In the sense as a verb, geodesign is about asking questions and as a noun, geodesign is the content of the answers. In this book Steinitz not only clears up the meaning of geodesign but more importantly provides a comprehensive framework (based on his past work) for thinking about strategies of geodesign, and for organising and operationalizing these meanings.

The book is made up of twelve chapters and split into four parts. The first part is spent on framing geodesign and to set the scene for the remainder of book. For example, chapter 1 notes that for geodesign to be successful, one requires collaboration between the design professions (e.g. architects, planners, urban designers, etc.), geographical sciences (e.g. geographers, ecologists, etc), information technologies and those people living within the communities where geodesign is being applied. This is reiterated throughout the book. Chapter 1 also traces the history of geodesign, and how the advent of computer methods for the acquisition, management and display of digital data can be used to link many participants, thus making design not a solitary activity. Chapter 2 introduces the reader to the context for geodesign in the sense that 1) geography matters and that different societies think differently about their geography, 2) scale maters in the sense of what scale should a geodesign project be applied at (e.g., local, regional or global), and what are the appropriate considerations that need to incorporated at each scale, and finally 3) size matters, if the size of the geographic study area increases, there is a high risk of a harmful impact if one makes a mistake.

Part 2 of the book lays out a framework for geodesign. It is important to note that Steinitz does not call this a methodology for geodesign, as he argues one cannot have a singular methodology as the approaches, principles and methods are applied to projects across a range of geographies, scales and sizes. He therefore introduces a framework as a verb, specifically for asking questions, choosing among many methods and seeking possible answers. In order to develop this framework Steinitz walks the reader through six different questions and types of models common in geodesign projects.

Chapter 3 focuses on components of the framework and the questions one needs to address for a successful geodesign project. These questions broadly range from: 1) How should the study area be described? 2) How does the study area operate? 3) Is the current study area working well? 4) How might the study area be altered? 5) What differences might the changes cause?, and finally, 6) How should the study area be changed? As posed by Steinitz, these questions are not a linear progression, but have several iterative loops and feedbacks both with the geodesign team and the application stakeholders. Moreover, Steinitz argues that such questions should be asked three times during the geodesign study, the first to treat them as why questions (e.g. to understand the geographic study area and the scope of the study). Secondly, the questions are asked in reverse order to identify the how questions (e.g. to define the methods of the study, therefore geodesign becomes a decision rather than data driven process) and finally, the questions are asked in sequential order to address the what, where and when questions as the geodesign study is being implemented. Once these three iterations are complete, there can be three possible decisions, yes, no and maybe. If maybe or no, more feedback is needed between the geodesign team and the stakeholders. These iterations highlight how geodesign is an on-going process of changing geography by design.


Using this framework, Chapter 4 discusses the first iteration of questions, that of scoping the geodesign study. The emphasis of this iteration is ensuring that it is being decision-driven as opposed to data-driven. Moreover, it goes over the six questions in an attempt to identity the intended scope for the study before looking at a feasible methodological plan. Chapter 5, moves onto the second iteration, that of designing the study methodology. Having identified the scope of the study (the why) from the first iteration, the geodesign team must then explore how it will be carried out and what are the evaluation criteria. Chapter 6 discusses the third iteration, that of carrying out the geodesign study. That of the what, where and when questions. Throughout these chapters, Steinitz reiterates the need for stakeholder input and feedback from the geodesign team. Moreover, at the end of chapter 6, Steinitz reiterates that the choices mater. The why questions provide a sense of the scope and objectives of the design application: the problem, the study area and those scales required for operationalizing a successful project.

Part 3 of the book looks at nine case studies in geodesign from around the world. Ranging in temporal scale from days to years, from no financial budget to a large budget, and from a small to large numbers of participants. These case studies helped solidify many of the concepts identified in the preceding chapters. They range from urban growth, to urban change to that of fire management. The case studies focus on specific places and utilize GIS with a variety of different techniques, from anticipatory modelling to that of participatory modelling and rule based models (e.g. cellular automata). They also show the importance of visualisation, as Steinitz (2012) notes “spatial visualisation can significantly influence decision making” (p 168). These examples have details but not depth (however, references are given to the full case study report), but this reiterates the purpose of the book, in the sense it is not a “how to” textbook or listing technologies that enable geodesign. It is a discussion with examples of geodesign. Or to quote from the last page of the book “you cannot copy an example but you can gain experience by joining the collaborative activities of geodesign and changing geography by design” (Steinitz, 2012, p 201). The same goes for the applications, they give a valuable insight into what is possible with geodesign. The book concludes by discussing the future applications for geodesign which range from looking at the implications for research in geodesign, and sketching out a geodesign support system (see Ervin, 2011); and in a sense, one could relate this to other planning support systems (see Brail, 2008), but with a greater emphasis on design.

Overall the book is extremely well written and Steinitz provides a critical and personal account of geodesign, which shows his expertise in the area from his years of teaching and carrying out geodesign work. The use of figures and real world examples really helps support the discussion. But if you are looking for a textbook for “how to” do geodesign, or a list of technologies that enable geodesign, you need to look elsewhere. This is a book the principles and practice of geodesign in a general sense, and which provides a valuable resource for those interested in this topic."

References:
Brail, R.K. (ed.) (2008), Planning Support Systems for Cities and Regions, Lincoln Institute of Land Policy, Cambridge, MA.
Ervin, S. (2011), 'A System for GeoDesign', Proceedings of Digital Landscape Architecture, Anhalt University of Applied Science, Dessau, Germany, pp. 145-154.
Goodchild, M.F. (2010), 'Towards Geodesign: Repurposing Cartography and GIS?.' Cartographic Perspectives, 66(7-22).
Longley, P.A., Goodchild, M.F., Maguire, D.J. and Rhind, D.W. (2010), Geographical Information Systems and Science (3rd Edition), John Wiley & Sons, New York, NY.
Steinitz, C. (1995), 'Design is a Verb; Design is a Noun', Landscape Journal, 14(2): 188-200.
Steinitz, C. (2012), A Framework for Geodesign: Changing Geography by Design, ESRI Press, Redlands. CA.
Full reference to the book:
Review of Steinitz, C. (2012), A Framework for Geodesign: Changing Geography by Design, ESRI Press, Redlands. CA.
Full reference to the review:

Crooks, A.T. (2013), Crooks on Steinitz: A Framework for Geodesign: Changing Geography by Design, Environment and Planning B, 40 (6): 1122-1124.


Tuesday, November 19, 2013

Geosimulation Models - AAG 2014: Call for Papers



GEOSIMULATION MODELS

DESCRIPTION OF THE SESSION(S)
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.

Papers will discuss issues relating to:
  • Validation, verification and calibration of Agent-based and CA models
  • Hybrid modeling approaches (e.g. utilizing Spatial Interaction, Microsimulation, etc.)
  • Handling scale and space issues
  • Visualization of agent-based models (along with their outputs)
  • Ways of representing behavior within models of geographical systems
  • Participatory modeling and simulation
  • Applications: Ranging from the micro to macro scale
Please e-mail the abstract and key words with your expression of intent to Andrew Crooks by November 28th, 2013. Please make sure that your abstract conforms to the AAG guidelines in relation to title, word limit and key words and as specified at http://www.aag.org/cs/annualmeeting/call_for_papers;. An abstract should be no more than 250 words that describes the presentation's purpose, methods, and conclusions as well as to include keywords. Full submissions will be given priority over submissions with just a paper title.

ORGANIZERS:
Andrew Crooks, Computational Social Science, George Mason University.
Suzana Dragicevic, Department of Geography, Simon Fraser University.
Paul Torrens, Department of Geographical Sciences and Institute for Advanced Computer Studies, University of Maryland.

TIMELINE:
November 19th, 2013: Second call for papers


November 28th, 2013: Abstract submission and expression of intent to session organizers. E-mail Andrew Crooks by this date if you are interested in being in this session. Please submit an abstract and key words with your expression of intent. Full submissions will be given priority over submissions with just a paper title.

November 29th, 2013: Session finalization. Session organizers determine session order and content and notify authors.

December 2st, 2013: Final abstract submission to AAG, via www.aag.org. All participants must register individually via this site. Upon registration you will be given a participant number (PIN). Send the PIN and a copy of your final abstract to Andrew Crooks. Neither the organizers nor the AAG will edit the abstracts.

December 3rd, 2013: AAG registration deadline. Sessions submitted to AAG for approval.

April 8th -12th, 2014: AAG meeting, Tampa Bay, Florida, USA.

Monday, November 04, 2013

The New Science of Cities

Readers of this blog may be interested in Michael Batty's new book "The New Science of Cities" which has just been published  by MIT Press. To quote from the publisher:
"Michael Batty suggests that to understand cities we must view them not simply as places in space but as systems of networks and flows. To understand space, he argues, we must understand flows, and to understand flows, we must understand networks—the relations between objects that comprise the system of the city. Drawing on the complexity sciences, social physics, urban economics, transportation theory, regional science, and urban geography, and building on his own previous work, Batty introduces theories and methods that reveal the deep structure of how cities function."

There is a detailed description of the books content on  Mike's web site www.complexcity.info. The website also hosts numerous papers and books that Mike has written over his many years as a leading urban modeler in all its shapes and forms.



Tuesday, October 22, 2013

New Paper: Measuring Slum Severity in Mumbai and Kolkata

In a move to understand slums, we have switch gears slightly from agent-based modeling to a more statistical study of slums.  To this end we have just received word that our paper entitled "Measuring Slum Severity in Mumbai and Kolkata: A Household-based Approach" has just been Habitat International. Specifically we propose a new household level enumeration of slums and develop a Slum Severity Index as shown Table 4 below. Morover, the paper estimates number of slum households in Mumbai and Kolkata as shown in Figure 1 (below). Furthermore, the paper demonstrates that varying slum definitions result into stark differences in slum population estimates. Paper abstract:
"Slums pose a significant challenge for urban planning and policy as they provide shelter to a third of urban residents. UN-Habitat reports that, in 2001, approximately 924 million people lived in slums or informal settlements across the world (UN-Habitat, 2003). However, varying definitions of what constitutes a slum result in different slum population estimates. Most definitions treat a slum as a community of several households, rarely recognizing that housing conditions differ for each individual household within the area. Moreover, definitions of slums usually take a dichotomous approach whereby a place is either a slum or not. Little attempt is made to go beyond this slum/non-slum dichotomy. This paper moves beyond the traditional ways of defining a slum by proposing a new household level enumeration of slums and developing Slum Severity Index (SSI), which measures the level of deprivation on a continuous scale based on the UN-Habitat's slum definition. We apply this new approach of analyzing slums to a household survey dataset to estimate the total number of slum households in Mumbai and Kolkata, two megacities in India. To contrast our approach, we compare these estimates with the Census of India's. The comparison highlights stark differences in the two estimates and the slum/non-slum household classifications. The estimates by the Census are considerably smaller than those based on the UN-Habitat definition in both cities. By applying the SSI, we also demonstrate intra-urban variability in housing conditions within our study cities. The analysis highlights differences in slum profiles measured in terms of both housing deprivation levels and housing deprivation types in both cities. The main objective of this study is to demonstrate the usefulness of the household level analysis of slums in drawing implications for designing and implementing slum policies."
Keywords: Slums, Definition, Deprivation, India, Housing.


Full Reference: 
Patel, A., Koizumi, N. and Crooks, A.T. (2014), Measuring Slum Severity in Mumbai and Kolkata: A Household-based Approach, Habitat International, 41: 300-306. (pdf)
If you would like to read the paper and don't have access to Habitat International, feel free to send us an email and we can send you an early version of the paper.

Monday, October 21, 2013

IR: State-Driven and Citizen-Driven Networks

Our work exploring how social media can be used to study events around the world has resulted in a new publication in the  Social Science Computer Review entitled "International Relations: State-Driven and Citizen-Driven Networks." In essence what we are attempting to do is compare traditional international relations (e.g. from the United Nations General Assembly voting patterns) to those arising from the bottom up interactions (i.e from people on the ground). The abstract of the paper is below along with some of the images that accompany the paper.
The international community can be viewed as a set of networks, manifested through various transnational activities. The availability of longitudinal datasets such as international arms trades and United Nations General Assembly (UNGA) allows for the study of state-driven interactions over time. In parallel to this top-down approach, the recent emergence of social media is fostering a bottom-up and citizen driven avenue for international relations (IR). The comparison of these two network types offers a new lens to study the alignment between states and their people. This paper presents a network-driven approach to analyze communities as they are established through different forms of bottom-up (e.g. Twitter) and top-down (e.g. UNGA voting records and international arms trade records) IR. By constructing and comparing different network communities we were able to evaluate the similarities between state-driven and citizen-driven networks. In order to validate our approach we identified communities in UNGA voting records during and after the Cold War. Our approach showed that the similarity between UNGA communities during and after the Cold War was 0.55 and 0.81 respectively (in a 0-1 scale). To explore the state- versus citizen-driven interactions we focused on the recent events within Syria within Twitter over a sample period of one month. The analysis of these data show a clear misalignment (0.25) between citizen-formed international networks and the ones established by the Syrian government (e.g. through its UNGA voting patterns).


Full reference:
Crooks, A.T., Masad, D., Croitoru, A., Cotnoir, A., Stefanidis, A. and Radzikowski, J. (2013), International Relations: State-Driven and Citizen-Driven Networks, Social Science Computer Review. DOI:10.1177/0894439313506851 (pdf)
If you don't have access to Social Science Computer Review, send us an email and we can send you an early version of the paper. This is also only part of our work on using multiple networks to explore international relations. One can of course also explore the networks in more detail. For example in the figure below we plot the actual transfer of arms between states during the 2001 and 2011 period. One can clearly see how different states are connected with Syria however, Russia has connections to many states.

Arms transfers

Or if we explore Twitter hastags and add an edge between any pair of hashtags when they are used in the same tweet we can explore an emergent ontology of topic labels users associate with each other. For example, the #Allepo hashtag is associated with other hashtags which appear to local events, including “#civilian”, “#airstrike”, “#hunger”, “#pictures”, many of which are only connected to the #Aleppo hashtag as shown below.



Monday, October 07, 2013

Interurban Simulation Models

Following on from a previous post about the rise of civilizations. I thought it was worth blogging of another publication which I just came across in Environment and Planning A which demonstrates the utility of agent-based modeling for looking at urban systems by Denise Pumain and Lena Sanders. While I have blogged about the SimPop models before (here), which explore a systems of cities and how they evolve in space and time. In this recent paper the authors compare and contrast ABM with other styles of modeling. To quote from the paper:
"Agent-based models are increasingly used by urban specialists, supplanting the simulation models using differential equations which were more popular earlier. These models already made reference to the theories of self-organisation and to mechanisms of evolution not so far from those used today to describe the emergence of macroscopic properties or structures in a bottom-up process from interactions operating at the microlevel. Moreover there is less difference than often suggested in the literature between the two forms of modelling – differential equations and multi-agent models—in the way they integrate principles of urban theory. To test this assumption, we compare models made of systems of differential equations (Allen’s model firmly rooted in self-organisation theory and the model developed by Weidlich and Haag, affiliated to synergetic theory) with multi-agent models (SIMPOP family) designed to meet the same task: simulating the differentiated dynamics of urban entities over the medium to long term from their functional economic specialisation. We show that multi-agent systems are providing interesting solutions for the modelling method, because of their greater ability to simulate the emergence of geographical macro structures from different levels of interaction." 


Full Reference:
Pumain, D. and  Sanders, L. (2013). Theoretical principles in interurban simulation models: a comparison. Environment and Planning A, 45(9), 2243-2260.
 

The Rise of Civilizations

Have you ever wondered how today's societies have evolved the way they have? A recent paper by Peter Turchin and colleagues explores through a geographically explicit agent-based model such a question. To quote from the paper:
"How did human societies evolve from small groups, integrated by face-to-face cooperation, to huge anonymous societies of today? Why is there so much variation in the ability of different human populations to construct viable states? We developed a model that uses cultural evolution mechanisms to predict where and when the largest-scale complex societies should have arisen in human history. The model was simulated within a realistic landscape of the Afroeurasian landmass, and its predictions were tested against real data. Overall, the model did an excellent job predicting empirical patterns. Our results suggest a possible explanation as to why a long history of statehood is positively correlated with political stability, institutional quality, and income per capita."



Full Reference:
Turchin, P., Currie, T. E., Turner, E. A., and Gavrilets, S. (2013). War, space, and the evolution of Old World complex societies. Proceedings of the National Academy of Sciences, 201308825.

Monday, September 30, 2013

Geosimulation Models - AAG 2014: Call for Papers


GEOSIMULATION MODELS

DESCRIPTION OF THE SESSION(S)
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.

Papers will discuss issues relating to:
  • Validation, verification and calibration of Agent-based and CA models
  • Hybrid modeling approaches (e.g. utilizing Spatial Interaction, Microsimulation, etc.)
  • Handling scale and space issues
  • Visualization of agent-based models (along with their outputs)
  • Ways of representing behavior within models of geographical systems
  • Participatory modeling and simulation
  • Applications: Ranging from the micro to macro scale
Please e-mail the abstract and key words with your expression of intent to Andrew Crooks by November 28th, 2013. Please make sure that your abstract conforms to the AAG guidelines in relation to title, word limit and key words and as specified at http://www.aag.org/cs/annualmeeting/call_for_papers;. An abstract should be no more than 250 words that describes the presentation's purpose, methods, and conclusions as well as to include keywords. Full submissions will be given priority over submissions with just a paper title.

ORGANIZERS:
Andrew Crooks, Computational Social Science, George Mason University.
Suzana Dragicevic, Department of Geography, Simon Fraser University.
Paul Torrens, Department of Geographical Sciences and Institute for Advanced Computer Studies, University of Maryland.

TIMELINE:
September 30th, 2013: First call for papers.
November 19th, 2013: Second call for papers


November 28th, 2013: Abstract submission and expression of intent to session organizers. E-mail Andrew Crooks by this date if you are interested in being in this session. Please submit an abstract and key words with your expression of intent. Full submissions will be given priority over submissions with just a paper title.

November 29th, 2013: Session finalization. Session organizers determine session order and content and notify authors.

December 2st, 2013: Final abstract submission to AAG, via www.aag.org. All participants must register individually via this site. Upon registration you will be given a participant number (PIN). Send the PIN and a copy of your final abstract to Andrew Crooks. Neither the organizers nor the AAG will edit the abstracts.

December 3rd, 2013: AAG registration deadline. Sessions submitted to AAG for approval.

April 8th -12th, 2014: AAG meeting, Tampa Bay, Florida, USA.

Saturday, September 21, 2013

Not in Focus: Stories from Ahmedabad Slums


As some readers might know, I been doing some work with Amit Patel and Naoru Koizumi on slums. To show some of this work we have organised a photo exhibation. If you are in the DC area feel free to pass by and say hello.

Not in Focus: Stories from Ahmedabad Slums


School of Public Policy, Krasnow Institute for Advanced Study and Arts Management Program at George Mason University are pleased to invite you to the Founders Art Gallery on:


Tuesday, October 1, 2013
5:30 - 7:30 pm
Founders Art Gallery, George Mason University, Arlington Campus
3351 Fairfax Dr, Arlington, VA 22201 (Click here for a map)

Featuring:
A photo exhibition that takes you inside the slums of Ahmedabad, India to experience challenges and indigenous solutions of citizens who are rarely in focus in the development process. (Exhibition will remain open through November 3, 2013). The photographs featured result from a research grant funded by NSF on slum formation in Ahmedabad, India, collaboratively carried out by George Mason University, CEPT University (India) and SAATH (India).

Screening of:
The Fourth World: A widely acclaimed documentary by Mark Volkers on individuals from slums around the world.
5:30 - 6:30 pm

Reception to follow
6:30 - 7:30 pm

This event is Free and Open to the Public. <<RSVP Here>>

Contact Amit Patel at apatelh@gmu.edu for queries.


Thursday, September 19, 2013

U.S. Synthetic Population Viewer


I have blogged before about a project that is creating a synthetic population for each household and person in the U.S. based on 2005-2009 ACS public use microdata and other data sources. Now one can view this information with an on-line viewer. Whats interesting about the viewer is that you can visually explore combinations of income, household size, and household age across the U.S. More information about the project can be found here, while the actual data can be downloaded from here.

Work featured in IQT Quarterly

Two of our recent papers have been  featured in IQT Quarterly. The first looks at completeness and error in VGI and the second features some of our work on social media and polycentric communities. The papers have been significantly shortened and edited and make easy reading (that's not to say the original papers were difficult to read :). For those not familiar with IQT Quarterly, it  is a publication from In-Q-Tel which: 
"was created to bridge the gap between the technology needs of the U.S. Intelligence Community (IC) and emerging commercial innovation".
Full References:
Stefanidis, A., Cotnoir, A., Croitoru, A., Crooks, A.T., Radzikowski, J. and Rice, M. (2013), Demarcating New Boundaries: Mapping Virtual Polycentric Communities through Social Media Content, IQT Quarterly, 5 (2): 12-14. (pdf)

Jackson, S. P., Mullen W., Agouris, P., Crooks, A. T., Croitoru, A. and Stefanidis, A. (2013), Assessing Completeness and Spatial Error of Features in Volunteered Geographic Information, IQT Quarterly, 5 (2): 22-26. (pdf)

Monday, September 16, 2013

Land-use, livelihood strategies, and sustainability

People interested in exploring the connections between land-use, livelihood strategies, and sustainability should check out Nicholas Magliocca from the Agent-Based Virtual Labs blog who  has a new a paper entitled " Exploring Agricultural Livelihood Transitions with an Agent-Based Virtual Laboratory: Global Forces to Local Decision-Making" Not only does the paper show the strengths of using agent-based modeling for enriching our understanding of the relationships between agricultural intensity and population density but also highlights how a growing trend in sharing model code and utilizing the ODD protocol for documenting the model which can aid in understanding the model but also for model replication. Its only a shame more modelers don't do this.


Sunday, September 15, 2013

Geosocial Gauge Paper


As regular readers of the blog know, we have been spending a lot of time recently looking at social media and the growth in locational information within such media. To this end we are very happy to see one of our papers appear in the International Journal of Geographical Information Science. The paper is entitled "GeoSocial Gauge: A System Prototype for Knowledge Discovery from Social Media" which in essence discusses the challenge of merging diverse social media datasets into a single database which can then be used to generate geosocial knowledge. Below is the abstract:
"The remarkable success of online social media sites marks a shift in the way people connect and share information. Much of this information now contains some form of geographical content because of the proliferation of location-aware devices, thus fostering the emergence of geosocial media – a new type of user-generated geospatial information. Through geosocial media we are able, for the first time, to observe human activities in scales and resolutions that were so far unavailable. Furthermore, the wide spectrum of social media data and service types provides a multitude of perspectives on real-world activities and happenings, thus opening new frontiers in geosocial knowledge discovery. However, gleaning knowledge from geosocial media is a challenging task, as they tend to be unstructured and thematically diverse. To address these challenges, this article presents a system prototype for harvesting, processing, modeling, and integrating heterogeneous social media feeds towards the generation of geosocial knowledge. Our article addresses primarily two key components of this system prototype: a novel data model for heterogeneous social media feeds and a corresponding general system architecture. We present these key components and demonstrate their implementation in our system prototype, GeoSocial Gauge."

Full reference:
Croitoru, A., Crooks, A.T., Radzikowski, J. and Stefanidis, A. (in press), GeoSocial Gauge: A System Prototype for Knowledge Discovery from Social Media, International Journal of Geographical Information Science. DOI: 10.1080/13658816.2013.825724 (pdf).
If you don't have access to IGIS, send us an email and we can send you an early version of the paper.

Tuesday, August 27, 2013

Modeling the outbreak, spread, and containment of tuberculosis

It seems my interest into disease models is growing. While the development of the cholera model is still underway, over the summer I have had been working with a very talented high school student looking at the outbreak, spread and containment of tuberculosis (TB). Why might you ask? TB is a global problem with 1.8 billion people having a TB Infection, 8.8 million people infected with the TB disease, and around 1.5 million annual deaths. It is the second most common form of death from an infectious disease with the majority of cases in developing countries.


So we have been developing a model that explores how TB might manifest itself, spread within an urban setting and the potential to contain the disease. We have chosen as our test case the Kibera slum within Nairobi, Kenya. Agents in this model represent the residents of the Kibera slum. They are mobile and goal-orientated, seeking to fulfill one goal before moving on to the next. Goals are determined based on the agent’s characteristics (age, sex, etc.) as well as their needs (water, food, health etc.). The exact location they choose to go to is also affected by the distance. When agents interact with one another, they can be infected with TB. Infection is determined upon the amount of bacilli absorbed by agents and their immune response. The transition from infection to disease for HIV positive patients is also dependent on the patient’s CD4 cell count.  What you see below is a poster we presented at Krasnow Institute Retreat.


To give a sense of the dynamics of the model, the movie below shows agents moving around the slum and how their health status changes as time progresses.



Wednesday, August 21, 2013

US/Mexico border

One of the models we are working on is the movement of people across national boarders. Below is a visualization of our work looking at the movement of people across the US/Mexico border which a specific focus on Arizona.

 

More specifically we are building analytical tools for border security that incorporate social, cultural, behavioral and organizational aspects of interactions among border security forces, smugglers and the population and represent integrated technology architectures made up of fixed and mobile sensor and surveillance networks. These tools provide critical capabilities that influence border security operations, planning, analysis and training.


System architecture

Click here to download the model. But read the instructions here first.


Research Outputs:

Latek, M. M., Mussavi Rizi, S. M., Crooks, A. T. and Fraser, M. (2012), A Spatial Multiagent Model of Border Security for the Arizona-Sonora Borderland. The Computational Social Science Society of America Conference, Santa Fe, NM. (pdf)

Latek, M. M., Mussavi Rizi, S. M., Crooks, A. T. and Fraser, M. (2012), Social Simulations for Border Security, Workshop on Innovation in Border Control 2012, Co-located with the European Intelligence and Security Informatics Conference (EISIC 2012), Odense, Denmark. (pdf)

Latek, M., Crooks, A. T., Rizi, S. and Fraser, M. (2012), Social Simulations For Border Security, 4th International Conference on Applied Human Factors and Ergonomics, 21st-25th July, San Francisco, CA. (pdf)

Crooks, A. T., Latek, M. M. and Mussavi Rizi, S. M. (2011) Computational Social Modeling of the Security of the Southern US Border, EADS North America Innovation Forum. 28th September, Arlington, VA.



Tuesday, July 30, 2013

ODD with human decision-making

In the Department of CSS, we often encourage our students when writing term papers (or any paper) with respect to agent-based models to use the Overview, Design concepts, and Details (ODD) Protocol (Grimm et al., 2006). This relates to the fact that is not only challenging building an agent-based model but also describing the model in enough detail to all for replication or comparison. Müller et al., (2013) have recently extended to ODD so that it is easier to have a standard way of describing decsion making within agent-based models.The paper is well worth a read.

Original Overview, Design concepts, and Details (ODD) protocol (Source: Grimm et al., 2006).



Extended ODD for describing human decisions in agent-based models – ODD + D (Source: Müller et al., 2013)
Full references to the papers:
Grimm, V., Berger, U., Bastiansen, F., Eliassen, S., Ginot, V., Giske, J., Goss-Custard, J., Grand, T., Heinz, S., Huse, G., Huth, A., Jepsen, J., Jorgensen, C., Mooij, W., Muller, B., Pe'er, G., Piou, C., Railsback, S., Robbins, A., Robbins, M., Rossmanith, E., Ruger, N., Strand, E., Souissi, S., Stillman, R., Vabo, R., Visser, U. and Deangelis, D. (2006), 'A Standard Protocol for Describing Individual-Based and Agent-Based Models', Ecological Modelling, 198(1-2): 115–126.
Müller, B., Bohn, F., Dreßler, G., Groeneveld, J., Klassert, C., Martin, R., Schlüter, M., Schulze, J., Weise, H. and Schwarz, N. (2013), 'Describing Human Decisions in Agent-based Models – ODD + D, An Extension of the ODD Protocol', Environmental Modelling and Software, 48: 37-48.

Thursday, June 20, 2013

Forest Fires

Recently I had a opportunity to catch up with Stephen Guerin who  was showing me their recent work with simtable.


With the recent spate of forest fires in the US,  Stephen and his group have also been capturing forest fire progressions such as the Thompson Ridge fire in NM, and have released a tool to embed the fires spread in your own browser as shown below.

Error: Embedded data could not be displayed.

MAIA Framework for ABM

Looking at frameworks and toolkits to easily create agent-based models, I recntly came across Modelling Agent systems based on Institutional Analysis (MAIA) framework via JASSS. The idea for MAIA is to lower the cost of implementing agent-based models. In the sense, you don't need to code the model from scratch but use a simple web interface. From first glance it appears to have the same ease of use as the Modelling4All project.

More information about MAIA can be found here.

Sunday, June 16, 2013

New Publication: GIS and Agent-Based models for Humanitarian Assistance

Inputs to the model
As the readers of the blog know, we have an interest in GIS, agent-based modeling and crowdsourcing. Now we have a paper that combines all these three elements. Its entitled "GIS and Agent-Based models for Humanitarian Assistance" and is published in Computers, Environment and Urban Systems. 
The model itself was written in MASON and uses extensively GeoMASON. Data comes from several different sources (both raster and vector) including OpenStreetMap and LandScan. Below you can read an abstract of the paper and see a movie of one of the scenarios.

"Natural disasters such as earthquakes and tsunamis occur all over the world, altering the physical landscape and often severely disrupting people’s daily lives. Recently researchers’ attention has focused on using crowds of volunteers to help map the damaged infrastructure and devastation caused by natural disasters, such as those in Haiti and Pakistan. This data is extremely useful, as it is allows us to assess damage and thus aid the distribution of relief, but it tells us little about how the people in such areas will react to the devastation. This paper demonstrates a prototype spatially explicit agent-based model, created using crowdsourced geographic information and other sources of publicly available data, which can be used to study the aftermath of a catastrophic event. The specific case modelled here is the Haiti earthquake of January 2010. Crowdsourced data is used to build the initial populations of people affected by the event, to construct their environment, and to set their needs based on the damage to buildings. We explore how people react to the distribution of aid, as well as how rumours relating to aid availability propagate through the population. Such a model could potentially provide a link between socio-cultural information about the people affected and the relevant humanitarian relief organizations."



Full Reference: 
Crooks, A.T. and Wise, S. (2013), GIS and Agent-Based models for Humanitarian Assistance, Computers, Environment and Urban Systems, 41: 100-111. (pdf)

Tuesday, June 04, 2013

Completeness and Spatial Error of Features in VGI

I have had an interest in volunteered geographic information (VGI) for quite some time (see my publications or blog posts) but only recently have I had an opportunity to look at the spatial error of features within VGI. To this end, our paper entitled "Assessing Completeness and Spatial Error of Features in Volunteered Geographic Information" has just been published in ISPRS International Journal of Geo-Information. Below is the abstract of the paper along with some figures. Further details about the paper can be seen at the bottom of the page.
The assessment of the quality and accuracy of Volunteered Geographic Information (VGI) contributions, and by extension the ultimate utility of VGI data has fostered much debate within the geographic community. The limited research to date has been focused on VGI data of linear features and has shown that the error in the data is heterogeneously distributed. Some have argued that data produced by numerous contributors will produce a more accurate product than an individual and some research on crowd-sourced initiatives has shown that to be true, although research on VGI is more infrequent. This paper proposes a method for quantifying the completeness and accuracy of a select subset of infrastructure-associated point datasets of volunteered geographic data within a major metropolitan area using a national geospatial dataset as the reference benchmark with two datasets from volunteers used as test datasets. The results of this study illustrate the benefits of including quality control in the collection process for volunteered data. 

Keywords: volunteered geographic information (VGI); OpenStreetMap; quality; error; point.
Comparison of OSM, OSMCP, and ORNL data.
Various identified locations of Southwest Early College
Full reference:
Jackson, S. P., Mullen W., Agouris, P., Crooks, A., Croitoru, A. and Stefanidis, A. (2013), Assessing Completeness and Spatial Error of Features in Volunteered Geographic Information, ISPRS International Journal of Geo-Information, 2 (2): 507-530. Download from here.

Friday, May 24, 2013

SFI Talks on YouTube

Via Twitter (@SFI_News), I have just come come across some excellent talks that took place at the Santa Fe Institute and thought they were worth sharing. At this time their YouTube channel has 95 videos ranging across complexity science such as the Emergence of Complex Societies and Cities, Scaling and Sustainability.


In another video which is relevant to some of the work we are doing at the Department of Computational Social ScienceLeysia Palen talks about "How Social Media Might Help You Survive the Next Big Disaster."


The SFI YouTube channel is really worth checking out.

Friday, May 10, 2013

Tweets from President Obama's inauguration 2013-01-21

Following on from a previous post on agent-based modeling and elections. Here we show geo-located tweets during the day of President Obama's inauguration 2013-01-21.


If you want to explore what people are currently saying about President Obama check out our Geosocial Gauge Website.

Screen shot of Geo social Gauge. Clockwise from top left: Location of tweets, basic sentiment of tweets (green positive, red: negative and gray: neutral), most active countries tweeting and a word cloud of the most popular words in the tweets.


Employment Growth through Labor Flow Network

    Omar Guerrero and Robert Axtell from the Department of Computational Social Science at GMU have recently published a paper in PLoS ONE entitled "Employment Growth through Labor Flow Networks." The work uses "newly available micro-data and the ability to work with large-scale, complex networks computationally, to study labor dynamics." Below is the abstract from the paper:

    It is conventional in labor economics to treat all workers who are seeking new jobs as belonging to a labor pool, and all firms that have job vacancies as an employer pool, and then match workers to jobs. Here we develop a new approach to study labor and firm dynamics. By combining the emerging science of networks with newly available employment micro-data, comprehensive at the level of whole countries, we are able to broadly characterize the process through which workers move between firms. Specifically, for each firm in an economy as a node in a graph, we draw edges between firms if a worker has migrated between them, possibly with a spell of unemployment in between. An economy's overall graph of firm-worker interactions is an object we call the labor flow network (LFN). This is the first study that characterizes a LFN for an entire economy. We explore the properties of this network, including its topology, its community structure, and its relationship to economic variables. It is shown that LFNs can be useful in identifying firms with high growth potential. We relate LFNs to other notions of high performance firms. Specifically, it is shown that fewer than 10% of firms account for nearly 90% of all employment growth. We conclude with a model in which empirically-salient LFNs emerge from the interaction of heterogeneous adaptive agents in a decentralized labor market.

      Communities of firms.

      To find more latest news from CSS check out our Facebook page.


      Thursday, May 09, 2013

      ABM & Elections

      Ever wondered if agent-based models have been applied to look at elections? I recently came across a nice little NetLogo model by Michael Laver which is part of the book "Party competition: an agent based model" (2012).


      This simple model allows users to explore the 2012 US presidential election campaign, Just like the election itself the model has two phases. 1) the  primary contest between the  Republican challengers.  2) The winner of the Republican primary then goes head to head with the Democratic incumbent.

      Monday, April 08, 2013

      GeoSocial Gauge



      Over the last couple of months we have been working on getting our GeoSocial Gauge system up and running. The idea behind the website is to bring together social media and geographical analysis to monitor and explore people’s views, reactions, and interactions through space and time. It takes advantage of the emergence of social media to observe the human landscape as the living, breathing organism that it is: we can witness the explosion-like dissemination of information within a society, or the clusters of individuals who share common opinions or attitudes, and map the locations of these clusters. This is an unprecedented development that broadens drastically our understanding of the way that people act, react to events, and interact with each other and with their environment. We refer to this novel approach to study the integration of geography and society as GeoSocial Analysis.

      The GeoSocial Gauge has several live streams ranging from exploring the political issues (e.g. Sequester) to to see what people are tweeting about TV (The Walking Dead).

      Screen shot of GeoSocial Gauge of the Sequester. Showing the location of tweets, the most frequent words and whether or not the messages are positive (green) or negative (red).
      Screen shot of GeoSocial Gauge of The Walking Dead.
      Some of our initial work on this type of analyis can be found at:
      • Stefanidis, T., Crooks, A.T. and Radzikowski, J. (2013), Harvesting Ambient Geospatial Information from Social Media Feeds, GeoJournal, 78, (2): 319-338.
      • Crooks, A.T., Croitoru, A., Stefanidis, A. and Radzikowski, J. (2013), #Earthquake: Twitter as a Distributed Sensor System, Transactions in GIS, 17(1): 124-147.



      Friday, April 05, 2013

      Compuational Social Science @ GMU

      The Department of Computational Social Science (CSS) at George Mason University is the first of its kind. It has active PhD, Master and Certificate programs in CSS. If readers are wondering what CSS is hopefully the quote from our Facebook page should help:
      Computational Social Science is the interdisciplinary science of complex social systems and their investigation through computational modeling and related techniques. The field is at the intersection of social science and computer science and spans anthropology, economics, political science, sociology, and social psychology - as well as allied disciplines such as geography, history, organization theory, regional science, communication, and linguistics. We additionally utilize developments in psychology, cognitive science, neuroscience, and related branches of behavioral science for understanding social phenomena.

      Computational approaches utilized and taught within the department include agent-based social simulation models (multi-agent systems), social network analysis, mathematical analysis based on complexity theory, social geospatial modeling methods (GIS), and automated information and content analysis methods. Through such computational methods we provide our students with a unique toolset to investigate social phenomena.

      If you are interested in finding out what the Department of CSS is doing or want to view some of our models you might like to check out our Facebook page.


      Wednesday, March 13, 2013

      GAMA (Gis & Agent-based Modelling Architecture) Platform

      While I have blogged about creating geographically explicit agent-based models with Repast, MASON, NetLogo and several other toolkits before, I recently came across an open source toolkit called Gis & Agent-based Modelling Architecture or GAMA for short. GAMA is developed by UMMISCO and to quote from the site:
      "GAMA is a simulation platform, which aims at providing field experts, modelers, and computer scientists with a complete modeling and simulation development environment for building spatially explicit agent-based simulations." 
      The site offers a series of tutorials, supporting documents and publications which show the potential of GAMA. The movie below gives an excellent overview of what GAMA can do. 



      Agent-Based & Cellular Automata Models for Geographical Systems @ the AAG

      If you attending the AAG Annual Meeting this year, please feel free to come to our sessions entitled Agent-Based and Cellular Automata Models for Geographical Systems.

      LOCATION AND DATE
      Saturday, April 13th, from 8:00 AM to 6:00 PM in Angeleno, The LA Hotel, Level 2  

      DESCRIPTION OF THE SESSIONS
      The use of Agent-based Modeling (ABM) and Cellular Automata (CA) models within geographical systems are starting 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 agent-based models, CA (and associated methodologies) to discuss topics relating to: theory, technical issues and applications domains of ABM and CA within geographical systems.

      Papers will discuss issues relating to:
      • Validation, verification and calibration of Agent-based and CA models
      • Hybrid modeling approaches (e.g. utilizing Spatial Interaction, Microsimulation, etc.)
      • Handling scale and space issues
      • Visualization of agent-based models (along with their outputs)
      • Ways of representing behavior within models of geographical systems
      • Participatory modeling and simulation
      • Applications: Ranging from the micro to macro scale
      ORGANIZERS:
      Christopher Bone, Department of Geography, University of Oregon.
      Andrew Crooks, Computational Social Science, George Mason University.
      Suzana Dragicevic, Department of Geography, Simon Fraser University.
      Alison Heppenstall, School of Geography, University of Leeds.
      Michael Batty, Centre for Advanced Spatial Analysis (CASA), University College London.
      Amit Patel, School of Public Policy, George Mason University.

      SPONSORSHIPS:
      Geographic Information Science and Systems Specialty Group and the Spatial Analysis and Modeling Specialty Group

      SESSION OUTLINES:

      5150: 1: Methodological Advances (8:00 AM)
      Kirk Harland and Mark Birkin
      David O'Sullivan and George  Perry 
      James Millington, David O'Sullivan and George  Perry 
      Christopher Bone
      Anthony Jjumba and Suzana Dragicevic
      5250 Land-Use Models (10:00 AM)
      Jan Baetens and Bernard De Baets
      Haiyan Zhang and Clinton Andrews
      Moira Zellner, Daniel Milz, Leilah Lyons, Lissa Domoracki and Joshua Radinsky
      Atesmachew Hailegiorgis
      Amit PatelAndrew Crooks and Naoru Koizumi
      A Spatial ABM Approach to Explore Slum Formation Dynamics in Ahmedabad, India
      5450 Applications (2:00 PM)
      Bianica Pint and Andrew Crooks
      Ali Afshar Dodson
      Rongxu Qiu, Wei Xu and Shan Li
      Sarah Wise
      Majeed Pooyandeh and Danielle Marceau 

      5550 Applications (4:00 PM)

      Arnaud Banos, Sonia ChardonnelChristophe LangNicolas Marilleau and Thomas Thevenin 
      Ed Manley and Tao Cheng
      Yong Yang, Ana  Diez-RouxAmy Auchincloss, Daniel Rodriguez, Daniel Brown and Rick Riolo
      Andrew Crooks and Atesmachew Hailegiorgis
      Timothy Gulden and  Joseph Harrison