Friday, December 14, 2018

But Are These Data Cookies Reproducible?

I think it's very important to check the reproducibility of these data.

(Tasty, tasty reproducibility.)


(Tip of the cap to Javier Buldú.)

Update: Now that I think of it, "Sweet, sweet reproducibility." would have been better phrasing, given its larger set of allusions.

Wednesday, December 12, 2018

"Variability in Fermi–Pasta–Ulam–Tsingou Arrays Can Prevent Recurrences"

A paper of mine came out in final form today. Here are some details.

Title: "Variability in Fermi–Pasta–Ulam–Tsingou Arrays Can Prevent Recurrences"

Authors: Heather Nelson, Mason A. Porter, and Bhaskar Choubey

Abstract: In 1955, Fermi, Pasta, Ulam, and Tsingou reported recurrence over time of energy between modes in a one-dimensional array of nonlinear oscillators. Subsequently, there have been myriad numerical experiments using homogenous FPUT arrays in the form of chains of ideal, nonlinearly coupled oscillators. However, inherent variations (e.g., due to manufacturing tolerance) introduce heterogeneity into the parameters of any physical system. We demonstrate that such tolerances degrade the observance of recurrences, often leading to complete loss in moderately-sized arrays. We numerically simulate heterogeneous FPUT systems to investigate the effects of tolerances on dynamics. Our results illustrate that tolerances in real nonlinear oscillator arrays may limit the applicability of results from numerical experiments on them to physical systems, unless appropriate heterogeneities are taken into account.

Sunday, December 09, 2018

Lee Smith and Harold Baines Elected to Baseball's Hall of Fame by the Veterans Committee

Lee Smith and Harold Baines were elected to Baseball's Hall of Fame today by "Today's Game Era Committee", an incarnation of the Veterans Committee.

These are not good picks, especially the one of Harold Baines. They belong more in the Hall of Very Good, rather than in the Hall of Fame. They had very good careers and compiled large numbers in various stats, but in my opinion they don't belong in the Hall of Fame. One of the things to think about when considering whether a player raises or lowers the standards of the Hall at their position. In my view, Lee Smith is a borderline case and I would put him just below the border, but he was the all-time saves leader for a while (and, in general, I can see the arguments in his favor), and he got many Hall of Fame votes for years. Thus, I only view this as a mildly bad pick. I understand it, but I wouldn't put him in the Hall. Part of the issue with Lee Smith has always been the overrating of saves, and I am not surprised that he got in through the Today's Game Era Committee, given the many votes he got from writers over the years in the regular voting. So I can mostly understand his case. But Harold Baines? He was a very good player, but he really lowers the bar at his position. He never got a sniff from the writers, nor did he deserve it.

I'm looking forward to the regular ballot, which will get us Mariano Rivera (who may break the record for highest voting percentage), Edgar Martínez (finally!), Roy Halladay, and maybe (and hopefully!) Mike Mussina will make it. Those four all richly deserve enshrinement in the Hall of Fame.

Maybe Lee Smith's election will help Billy Wagner's case?

Friday, December 07, 2018

"'C' is for Cookie": Academic Evaluation Edition

Comment: "'C' is for cookie. That's good enough for me!"

Comment 2: Apparently, some of my what we did in mathematics in Somerville was an even better idea than I thought. ;)


(Tip of the cap to Jacquelyn Gill.)

Tuesday, December 04, 2018

Does Particle Man Hate Tariff Man?

Does Particle Man hate Tariff Man? And what about Triangle Man?

Jewelry and Differential Equations

I'm sure that many jewel thieves started on the road to crime after failed attempts to solve a differential equation.

Tales from the ArXiv: Laundering Anti-Money

This new paper has the following title: "Scalable Graph Learning for Anti-Money Laundering: A First Look"

Wow! I wonder what happens when laundered anti-money collides with laundered money?

Tuesday, November 27, 2018

Tales from the ArXiv: Grandma Got Run Over By a Reindeer

If I had done this study, I would make a video submission to the Gallery of Nonlinear Images (may it rest in peace), and I would set it to the tune of the song Grandma Got Run Over By a Reindeer. Just saying...

Extra Special Mathematics Terminology


Monday, November 26, 2018

"Motor Primitives in Space and Time via Targeted Gain Modulation in Cortical Networks"

Our paper officially came out in Nature Neuroscience today! Here are some details.

Title: Motor Primitives in Space and Time via Targeted Gain Modulation in Cortical Networks

Authors: Jake P. Stroud, Mason A. Porter, Guillaume Hennequin, and Tim P. Vogels

Abstract: Motor cortex (M1) exhibits a rich repertoire of neuronal activities to support the generation of complex movements. Although recent neuronal-network models capture many qualitative aspects of M1 dynamics, they can generate only a few distinct movements. Additionally, it is unclear how M1 efficiently controls movements over a wide range of shapes and speeds. We demonstrate that modulation of neuronal input–output gains in recurrent neuronal-network models with a fixed architecture can dramatically reorganize neuronal activity and thus downstream muscle outputs. Consistent with the observation of diffuse neuromodulatory projections to M1, a relatively small number of modulatory control units provide sufficient flexibility to adjust high-dimensional network activity using a simple reward-based learning rule. Furthermore, it is possible to assemble novel movements from previously learned primitives, and one can separately change movement speed while preserving movement shape. Our results provide a new perspective on the role of modulatory systems in controlling recurrent cortical activity.