Understanding cities with agents

Dear Jim,

Thanks for inviting me to write a guest entry on your blog about my research interests and background. It is actually quite strange writing on someone else’s blog rather than my own. Since starting at the Department of Computational Social Science in August, I have been overwhelmed with how friendly and supportive everyone has been.

Prior to arriving at GMU, I spent several years at the Centre for Advanced Spatial Analysis (CASA) at University College London, both as a PhD student and as a research fellow. My PhD was carried out under the supervision of Professors Mike Batty and Paul Longley and sponsored by the Greater London Authority (GLA) Economics unit. It focused on integrating geographical information systems (GIS) and agent-based models thus providing the ability to link agents to actual ‘real’ world places and explored general questions about residential location and spatial interaction. Specifically how agents locate and interact with their surrounding environment, along with how competition for land results in distinct spatial patterns emerging. This has subsequently led me to develop my research interests in agent-based modeling (ABM) of cities.

Cities are extremely important as they provide habitats for over half of the world’s population and this percentage is expected to increase further in future decades. This increase will cause many problems such as sprawl, congestion and segregation; along with environmental effects associated with land use and land cover change. However, understanding such systems is extremely complex because of the many different factors and activities that are seen within cities all of which operate at different temporal and spatial scales. As Professor Sir Alan Wilson writes, understanding cities represents “one of the major scientific challenges of our time.”

I believe that a greater understanding of cities can be gained through the use of agent-based models: from the split second decisions involving local movements such as people walking, to the development of land over months and years, the migration of peoples over decades, to the rise and fall of cultures and civilizations over eons. These processes all that have at their core people (in some shape or form), thus understanding the reasoning on which individual decisions are made may therefore help us better understand the effects of such growth. However, there are several challenges which need to be addressed ranging from validation of such models to the communication of models. More recently I have been exploring how one can take advantage of advances in digital data, 3D modeling environments and virtual worlds such as Second Life for the creation and outreach of agent-based models.

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These broad research interests have been the foundation of the graduate course that I am currently teaching this semester entitled “Agent-based Modeling of Urban Systems” which explores many aspects of urban systems from the micro-movement of pedestrians to residential dynamics. Next semester I will be teaching two classes. The first is “Spatial Agent-Based Models of Human-Environment Interactions” which explores how one can link socio economic and environmental models, along with GIS to study topics in areas such as agriculture, forestry, human/non human populations. The second course “Land-Use Modeling Techniques and Applications” focuses on a variety of land-use change models including cellular automata and agent-based models, along with exploring the drivers of change.

I am finding it great to be among a group of faculty, staff and students who are interested and extremely knowledgeable about ABM from a variety of backgrounds and I am looking forward to developing further links with people at GMU in the future.

Sincerely,

Andrew Crooks

Geo-engineering response to Climate Change: the opposition

Over at Science Progress, a very well written skeptical response by Joronen and Oksanen to those who are advocating large-scale geo-engineering as a response to climate change. Even if it’s a Plan B. My problem with the skeptics is this: given the high stakes, it seems better to have a Plan B than not. I have yet to hear of an alternative Plan B for run-away global warming.

Perhaps loyal readers can better inform me?

Jim

Francis Collins: somewhere between Varmus and Zerhouni

From today’s New York Times profile of new NIH director Francis Collins:

Dr. Collins’s predecessor, Dr. Elias A. Zerhouni, drove a silver Mercedes sports car to work and wore expensive suits, and those choices — along with a natural reserve and the unpopularity of President George W. Bush, who appointed him — meant he was never entirely embraced by the thousands of rumpled scientists who make up the core of the health institutes’ staff.

That he was a brilliant scientist and had highly developed organizational skills never won him plaudits outside of the agency’s top leaders, many of whom praised Dr. Zerhouni effusively.

By contrast, Dr. Zerhouni’s predecessor, Dr. Harold Varmus, rode a bicycle to work, wore khakis and was beloved.

With his high-end motorcycle, Dr. Collins seems to be splitting the difference between his predecessors. But he is distinctly in Dr. Varmus’s camp on clothing, and he has promised to be far more open than either. He has held town-hall-style meetings with staff members, reporters and outsiders. And neither of his predecessors was given to meeting reporters at the nearby greasy spoon

Cox Lab Moves to Krasnow Institute

Dear Jim,



Many thanks for the opportunity to contribute to your blog. My research group and I are very excited to be moving our laboratory from the Prince William Campus to the beautiful new facilities at the Krasnow Institute for Advanced Study this Fall. Prior to joining the Department of Molecular and Microbiology at George Mason in Fall 2004, I completed my PhD in the laboratory of Dr. Haifan Lin at Duke University where my research focused on the molecular mechanisms governing stem cell regulation. I next went on to complete postdoctoral training as a Jane Coffin Childs Fellow in the laboratory of Dr. Yuh-Nung Jan at UCSF where my research focused on investigating the molecular and regulatory mechanisms governing class-specific dendrite morphogenesis.



Presently, my research laboratory is focused on a number of key areas of inquiry including the mechanisms by which the size, shape and complexity of dendritic arbors is achieved and subsequently regulated, how the boundaries of neuronal receptive fields are specified and refined, how dendrites function in mediating recognition between synaptic partners, and how dendritic fields are established, maintained and remodeled during development.



To investigate these questions, we use Drosophila genetics to dissect the molecular mechanisms mediating class specific dendrite morphogenesis. The Drosophila peripheral nervous system (PNS) serves as a molecular, genetic, morphological and physiological model system in which to investigate these processes. Specifically, our group is focused on the roles of transcriptional, cytoskeletal, cell surface receptor, and RNAi (siRNA/miRNA) regulatory mechanisms governing class-specific dendrite morphogenesis as they relate to dendritic field specification and dendritic tiling. We have also recently published a paper describing novel methods for the isolation and transcriptional expression profiling of class-specific neurons as a tool to investigate these processes.



Apart from my research program, I am currently the Graduate Program Director for the Biosciences PhD and M.S. Biology degree programs at Mason and am delighted to take on the role as Director for the new Confocal Imaging Core of the Krasnow Institute (C.I.C.K.I.).



I am particularly anxious to establish new collaborations with other Krasnow Investigators in the areas of high-resolution cellular imaging and neuroinformatics and look forward to interacting with all the faculty, students, and staff in the Neuroscience program.



Sincerely,



Dan Cox

Hard times for California

These are very hard times for my native state, but this Guardian piece (hat tip Slate) sees better times ahead. I hope so.

I do think that the troubles can be traced back to when the (in)famous Proposition 13 was passed. The first of several financially consequential initiatives (a result of California’s constitutional affection for direct democratic decision making), it lead to the State becoming overly dependent upon economic growth for the delivery of basic services.

Curating

So I wasn’t aware that as an institute director (and according the the NY Times), I’m a curator of scientists–but apparently I am. Here’s hoping that I have good taste in science.

Money quote:

The word “curate,” lofty and once rarely spoken outside exhibition corridors or British parishes, has become a fashionable code word among the aesthetically minded, who seem to paste it onto any activity that involves culling and selecting.

High anxiety at the Sunday Times Magazine

Robin Henig has an extensive piece in today’s Sunday New York Times Magazine focused on anxiety and the work of Harvard developmental psychologist Jerome Kagan (along with many of his students who are now independent investigators).

I found the piece to be curiously anecdotal in terms of its presentation of very extensive longitudinal data–perhaps satisfying for non-scientists, but quite frustrating for those of us who want to look at actual data to prove or disprove hypotheses.
Nevertheless, the piece raises the excellent question of the extent to which the phenomenon we call anxiety is deeply linked the the limbic brain structure called the amygdala. The latest fMRI studies are at least able to provide something beyond classic psychometric tests.

Timo Hannay’s notes on Joi Ito’s talk at Nature

Friend and colleague Timo Hannay at Nature took notes on Creative Common’s guru Joi Ito’s presentation there. Money quote:

CC licensing increases demand but cannibalises sales. So there’s a trade-off depending on the demand and sales of any given piece of work at any given time. The questions about CC licensing are therefore practical ones about what, who and when – not a religious decision. (Though for scientific and certain other types of content, CC believes in free access.)

In these situations, the communities often police themselves, enforcing social norms such as attribution and non-commercial restrictions. [Joi gave a Star Wars fan fiction example.] In some cases, fans create derivative versions (e.g., subtitled films) to encourage the publisher to release an official (paid) version, removing the amateur version when they succeed.