Friday, June 28, 2019
Title: Multivariate Spatiotemporal Hawkes Processes and Network Reconstruction
Authors: Baichuan Yuan, Hao Li, Andrea L. Bertozzi, P. Jeffrey Brantingham, and Mason A. Porter
Abstract: There is often latent network structure in spatial and temporal data, and the tools of network analysis can yield fascinating insights into such data. In this paper, we develop a nonparametric method for network reconstruction from spatiotemporal data sets using multivariate Hawkes processes. In contrast to prior work on network reconstruction with point-process models, which has often focused on exclusively temporal information, our approach uses both temporal and spatial information and does not assume a specific parametric form of network dynamics. This leads to an effective way of recovering an underlying network. We illustrate our approach using both synthetic networks and networks that we construct from real-world data sets (a location-based social-media network, a narrative of crime events, and violent gang crimes). Our results demonstrate that, in comparison to using only temporal data, our spatiotemporal approach yields improved network reconstruction, providing a basis for meaningful subsequent analysis—such as examinations of community structure and motifs—of the reconstructed networks.
Wednesday, June 26, 2019
Want to play every possible game configuration in (Settlers of) Catan? It will take a while. According to Austin, Kronenthal, and Miller's "Settlers of 'Catanbinatorics,'" that's 20,369,419,560 games. https://t.co/LMF8P9Gpfi pic.twitter.com/nzqiPUshVn— Dave Richeson (@divbyzero) June 25, 2019
Tuesday, June 25, 2019
Title: Nonlinear Excitations in Magnetic Lattices with Long-Range Interactions
Authors: Miguel Molerón, Chris Chong, Alejandro J. Martínez, Mason A. Porter, Panayotis G. Kevrekidis, and
Abstract: We study—experimentally, theoretically, and numerically—nonlinear excitations in lattices of magnets with long-range interactions. We examine breather solutions, which are spatially localized and periodic in time, in a chain with algebraically-decaying interactions. It was established two decades ago (Flach 1998 Phys. Rev. E 58 R4116) that lattices with long-range interactions can have breather solutions in which the spatial decay of the tails has a crossover from exponential to algebraic decay. In this article, we revisit this problem in the setting of a chain of repelling magnets with a mass defect and verify, both numerically and experimentally, the existence of breathers with such a crossover.
Monday, June 24, 2019
If you know me personally and you write to me by e-mail, and I do not respond in some form within a couple of days, I am probably dead. https://t.co/iCcuXGgGca— Mason Porter (@masonporter) June 25, 2019
Thursday, June 20, 2019
Here is the arXiv paper that led to the above popular piece.
Tuesday, June 18, 2019
Monday, June 17, 2019
Monk-dude with cool glasses gazing at the world around him while his fellow monks sing songs - manuscript datable to 1325-1350, which makes this an early depiction of spectacles (Besançon, BM, 140). pic.twitter.com/o43bnHHxn5— Erik Kwakkel (@erik_kwakkel) May 14, 2019
(Tip of the cap to Nicholas Christakis.)
Sunday, June 16, 2019
As quoted in the above entry in the Online Encyclopedia of Integer Sequences:
First few digits reproduce the digits of the phone number in the song "867-5309/Jenny" performed by Tommy Tutone.
The next digit is a 0, and the following 4 digits (1, 9, 8, 1) are the year the song was recorded (1981). (Noticed by Rob Johnson of the explainxkcd.com forums)
(Tip of the cap to Nalini Joshi. Nalini's tweet included a link to this old xkcd (which I had forgotten about, and I don't think I had ever followed the rabbit hole about Jenny's constant.)
(I am the one in bright red. It's because of my Cornell doctoral degree, but these are almost almost Somerville colors. You can tell the birds from the colors of their feathers.)
Many undergrads from my courses, as well as ones who are doing research projects with me, participated in the ceremony.
Before the ceremony, in the mathematics department lounge, our commencement speaker asked me if I was graduating. He said that I look very young, but I am more than a decade older than he is!
Friday, June 14, 2019
In 2011, I was honored and flattered when some of my @SomervilleOx students made a D & D character sheet for me: https://t.co/JOlvWpRI2b— Mason Porter (@masonporter) June 14, 2019
They were wrong about my alignment and my diety, but that's ok.
Also, I have a +5 Vorpal Red Pen and a Decanter of Infinite Ice Latte. pic.twitter.com/hMd9jzHHWt
P.S. In case you are interested, here is my 2011 blog entry and the discussion therein.
Mouseover text: "Somewhere, there's a scientist reading this, wonder[ing] why I made a comic with no hyperbole."
Some scientists get all the breaks pic.twitter.com/l327NT5vFd— Adam J Calhoun (@neuroecology) June 14, 2019
Wednesday, June 12, 2019
Wow, this intro to type theory book doesn’t mess around. pic.twitter.com/ESiSvmMPV9— Fogus’ Wake (@fogus) June 13, 2019
(Tip of the cap to David Bindel.)
Tuesday, June 11, 2019
Monday, June 10, 2019
Awesome talks by my students & postdocs at #SIAMDS19!— Mason Porter (@masonporter) June 10, 2019
Heather Brooks (@HZinnbrooks): https://t.co/SDWGU4tTeR
Michelle Feng (@michellehfeng): https://t.co/EpOQTqrsom
Yacoub Kureh (@Yacoub_Kureh): https://t.co/Y31nfpCjm7
Alice Schwarze (@aliceschwarze): https://t.co/k9Ete7BkEv pic.twitter.com/MGojbXkqdH
Sunday, June 09, 2019
It was awesome when Ichiro Suzuki paid homage to this incident last year.
Saturday, June 08, 2019
A typogram is a word or a series of words written and disposed in such a manner that they illustrates what they mean. Artist Aaron Kuehn brings the typograms at a new level by dwaring complex systems depicted using only the names of their parts https://t.co/xDlvbZ1YWO pic.twitter.com/jvMgWbeld4— Massimo (@Rainmaker1973) June 8, 2019
Friday, June 07, 2019
Japanese Artist Tightly Rolls Newspaper To Create Incredibly Realistic Animal Sculptures https://t.co/wgxGL3848A— Archpng (@archpng) June 8, 2019
Thursday, June 06, 2019
Tuesday, June 04, 2019
The heart of a man may be compared to a sausage; no one can tell exactly what's inside. — Jewish proverb— Yiddish Proverbs (@YiddishProverbs) June 4, 2019
(Tip of the cap to Benjamin E. Hardisty.)
Sunday, June 02, 2019
How can this not be a joke? https://t.co/2ZoAPBE4Pz— Carl T. Bergstrom (@CT_Bergstrom) June 3, 2019
Update: One of my friends was suggesting that this is a joke from the 'company', and that may be true. There are so many real ridiculous things nowadays that I find it hard to tell.
There are many cool things about this picture.
Based on my quick googling, however, this appears to be apocryphal.
I also like the idea of evoking apocalypses in related comments and puns.
Example usage: "I rewrote the sentence to avoid apostryphal grammar."