Sam A. Hill

A measure for characterizing heavy-tailed networks

Sam A. Hill. Physical Review Research 3: 023257 (2021).

In this paper I adapted a measure from statistics as a classification tool for different types of networks. I analyzed large datasets of network structures using Python with the NetworkX module.

Dynamic Model of Time-Dependent Complex Networks

S.A. Hill and D. Braha. Physical Review E 82: 046105 (2010).

In this paper, I collaborated with Dr. Dan Braha to study and model the concept of “dynamic centrality” discovered by himself and Dr. Yaneer Bar-Yam. I used C++ to construct preferentially weighted subnetworks of networks and measure their properties.

• Holding Strategies in a Bus-Route Model
  Sam A. Hill. arXiv:0709.0078 [physics.soc-ph] (2007). (not peer-reviewed)
• Numerical analysis of a time-headway bus route model
  S.A. Hill. Physica A 328: 261 (2003).

In these two papers, I studied a simple model of the phenomenon of bunching that occurs when one bus (or train) falls behind schedule, picks up more passengers, and becomes even later, while the bus behind has fewer passengers to pick up and so runs faster. The work was a combination of modelling, analytical calculations, and simulations written in C.

• Locomotive network modeling based on identified neurons in zebrafish
  D.K. Knudsen, J.T. Arsenault, S.A. Hill, D.M. O’Malley, and J.V. José. Neurocomputing 69: 1169-1174 (2006).
• Neurokinematic Modeling of Complex Swimming Patterns of the Larval Zebrafish
  S.A. Hill, Melissa A. Borla, Jorge V. José, and Donald M. O’Malley. Neurocomputing 65-66: 61-68 (2005).

As a post-doc at Northeastern University, I collaborated with a Biology group on the motions of larval zebrafish. I played a largely supporting role, constructing a visual simulation of a simple model of the fish’s motion in Tcl/Tk, and contributing several figures to the 2005 paper.

• Granular clustering in a hydrodynamic simulation
  S.A. Hill and G.F. Mazenko. Physical Review E 67: 061302 (2003).
• Nonlinear hydrodynamical approach to granular materials
  S.A. Hill & G.F. Mazenko. Physical Review E 63: 031303 (2001).

My doctoral research at the University of Chicago involved the study of a hydrodynamic model of granular materials such as sand, which can behave as both a solid or a liquid at various times. The research involved running multi-day calculations in C, analysis of large data files, and generation of the figures shown in the papers, some (e.g. Fig.5–6 in the 2003 paper) generated directly in Postscript.

• Entanglement of a pair of quantum bits
  Sam A. Hill and William K. Wootters. Physical Review Letters 78: 5022 (1997).

As an undergraduate, my advisor and I derived a formula for the entanglement of formation of a pair of bits. My part of the task was running gradient descent calculations in Mathematica on multiple computers in the physics lab at night.