I'm Rich Harang, a researcher for ICF International, currently working with the Army Research Labs on a variety of 6.1 research projects. Current areas of interest to me include Bayesian nonparametric models (particularly for time series), fast algorithms for large-scale machine learning (hash kernels, cover trees), and graphical models for both discovering latent structure in sequential data and investigating data that is itself samples from networks. I also have a hobby interest in cryptography as well as security applications of computational complexity.

Prior to working for ICF, I spent a year as a postdoctoral scholar in the Computational Science and Engineering Research Group at the University of California, Santa Barbara, under the direction of Dr. Linda Petzold, studying and modeling circadian oscillators and networked stochastic processes, in particular investigating the role that stochasticity plays in the behavior of networked systems. I spent some time looking into ways that we can infer topology from observations on the nodes of a network, and exploring how this network structure can allow systems to exploit stochastic behavior to their advantage rather than simply manage it away.

My dissertation, "Wavelet Analysis of Stochastic Circadian Oscillators" focused on using continuous wavelets to infer properties of oscillators driven by solutions to stochastic differential equations. I used the results to analyze bioluminescence data collected from the suprachiasmatic nucleus of rodents, including topological connectivity, classification of neurons, and using stochastic differential equations as a model of the neurons.

For fun, I do a bit of tinkering with computational statistics -- particularly Bayesian methods -- and try to apply them to whatever interests me at the time, very often political science. If you're interested, you can read about it at my personal blog (linked over on the left). It's a bit neglected these days, now that I'm gainfully employed, but I do manage to get something posted every once in a while.

I love talking about my work, and I'm always interested in exploring potential collaborations, so if you've got questions, feel free to contact me.