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Category: Modeling and Simulation

Brain Networks and the Cluster Variation Method: Testing a Scale-Free Model

Brain Networks and the Cluster Variation Method: Testing a Scale-Free Model

Surprising Result Modeling a Simple Scale-Free Brain Network Using the Cluster Variation Method One of the primary research thrusts that I suggested in my recent paper, The Cluster Variation Method: A Primer for Neuroscientists, was that we could use the 2-D Cluster Variation Method (CVM) to model distribution of configuration variables in different brain network topologies. Specifically, I was expecting that the h-value (which measures the interaction enthalpy strength between nodes in a 2-D CVM grid) would change in a…

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Ground-Truthing – The First Step in Predictive Analytics

Ground-Truthing – The First Step in Predictive Analytics

Ground Truthing – Your First Day in Class You may be joining me for the Summer 2015 class in Text Analytics (PREDICT 453) that I’ll be teaching through Northwestern University’s Master of Science in Predictive Analytics (MSPA) program, starting June 22, 2015. Or you may not. Either way, you can follow this class virtually – here through this blog. I’ll be posting lots of information about the upcoming class – and referencing my permanent pages that I’m setting up prior…

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Modeling the Future: Tools from Complex Systems

Modeling the Future: Tools from Complex Systems

2012 and Beyond: Tools for Predicting the Next Sixty Years Is the world coming to an end on Dec. 21st, 2012, or not? Very likely, not. We’ll still wake up in the morning, in the same beds in which we went to sleep in the night before. We’ll still walk out to our cars, or get to our Metro stations, on time. And we’ll likely stop for the same “cup of joe” on the way to work. But will our…

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Good Read on Modeling Social Emergent Phenomena – But Still Not There Yet!

Good Read on Modeling Social Emergent Phenomena – But Still Not There Yet!

Philip Ball – Critical Mass The most important thing we can do right now – given the huge changes ahead of us – both in society, the world, and technology – is to get some sort of “handle” on what’s coming up. By that, I mean a good set of models. And as a result, I’m on a search for good models. Those that I know, those that are new. Those that make sense, and those that don’t. (We need…

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Gibbs Free Energy, Belief Propagation, and Markov Random Fields

Gibbs Free Energy, Belief Propagation, and Markov Random Fields

Correspondence Between Free Energy, Belief Propagation, and Markov Random Field Models As a slight digression from previous posts – re-reading the paper by Yedidia et al. on this morning on Understanding Belief Propagation and its Generalizations – which explains the close connection between Belief Propagation (BP) methods and the Bethe approximation (a more generalized version of the simple bistate Ising model that I’ve been using) in statistical thermodynamics. The important point that Yedidia et al. make is that their work…

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What Makes a Metastable State Happen?

What Makes a Metastable State Happen?

Metastable States – the Meltdown Precursors I’ve just read a recent column by JL, one of the editors from Taipan Daily. He states, in his column “There Will Be Blood in Europe”: Stepping back a bit: What is so frightening right now, not just in Europe but China and America and Japan too, is the presence of fraud-fueled “Lehman 2.0” catalysts threatening to explode. One could say that the 2008 financial crisis was the mother of all wake-up calls. But…

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"What is X?" – Modeling the Meltdown

"What is X?" – Modeling the Meltdown

“What is X?” – Modeling the 2008-2009 Financial Systems Meltdown We’re about to start a detailed walkthrough of applying a “simple” statistical thermodynamic model to the Wall Street players in the 2007-2009 timeframe. The two kinds of information that I’ll be joining together for this will be a description of Wall Street dynamics, based largely on Chasing Goldman Sachs (see previous blogposts for link), and the two-state Ising thermodynamic model that I’ve been presenting over the past several posts. The…

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Modeling Nonlinear Phenomena

Modeling Nonlinear Phenomena

Modeling Nonlinear Phenomena – What is “X”? Many of us grew up hating word problems in algebra. (Some of us found them interesting, sometimes easy, and sometimes fun. We were the minority.) For most of us, even if we understood the mathematical formulas, there was a big “gap” in our understanding and intuition when it came to applying the formulas to some real-world situation. In the problem, we’d be given a set of statements, and then told to find “something.”…

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"Origins of Wealth" – A (Multi-Part) Critical Review

"Origins of Wealth" – A (Multi-Part) Critical Review

Over the last few months, questions of not only wealth and finances, but the underpinnings of our entire financial structure, have become paramount in many of our minds. We — that usually means you and me — and right now means the world collectively — have largely misunderstood the world’s financial structure over recent years. (Those who HAVE accurately understood are not only more secure, but substantially richer by now.) Most of us are current on “what went wrong.” Most…

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