Friday, February 28, 2020

An Otter's "Careless Whisper"

(Tip of the cap to Card Colm Mulcahy.)

Monday, February 24, 2020

"Automatic Generation of School Bus Routes in Los Angeles"

Our report for the UCLA Institute of Transportation Studies from our collaboration with the Los Angeles Unified School District (LAUSD) is now publicly available. Here are some details.

Title: Automatic Generation of School Bus Routes in Los Angeles

Authors: Mason A. Porter, David J. Spender, and Cu Hauw ("Willy") Hung

Abstract: The goal of our project is to automatically generate school bus routes for the Los Angeles Unified School District (LAUSD). We examined four algorithms, including two from the existing literature and two new ones that we developed. A major focus of our work was the construction of “mixed-load routes,” which transport students from multiple schools. Based on our measurements (whose imperfections we discuss), three of the four algorithms perform at least as well as the existing route plan, and one of those three performs better than the existing route plan. We also delivered a user-friendly routing program to LAUSD that uses one of these algorithms, and we have made our software publicly available. Our insights and results are also applicable to other school districts that permit mixed-load routing.

Sunday, February 23, 2020

A Comic-Book Café in Korea


I want to go and hang out in this café.

(And I want to play "Take On Me" as background music while I am there.)

Saturday, February 22, 2020

Sunday, February 16, 2020

Stay Tuned for My Mathematics Opinion Piece :)

In case you're wondering, the correct analogy (which you'll understand if you are familiar with Dragonlance) is "Tasslehoff was bored." (Nothing on Krynn is more dangerous than a bored kender.)

A sudden thought: I wonder if this counts as an Invited Tirade?

Saturday, February 15, 2020

"Contributed Tirades"

My contribution is "Contributed Tirades". I wonder if I have ever had any Invited Tirades?

Thanks to Dan Larremore for the inspiration!

Tuesday, February 04, 2020

Dodgers Acquire Mookie Betts (and David Price)!

The Dodgers have acquired Mookie Betts in a trade with the Boston Red Sox! In addition to Betts, we get David Price, who is still a good pitcher (although he is worth much less than his hefty salary these days). Alex Verdugo goes to the Red Sox and Kenta Maeda goes to the Minnesota Twins, who are sending prospect Brusdar Graterol to the Red Sox.


Update: And right after the big trade above, the Dodgers traded Joc Pederson to the Los Angeles Angels for infielder Luis Rengifo.

Update (2/09/20): After the original version of the trade hit a snag (because of a medical test on Brusdar Graterol), the Dodgers, Red Sox, and Twins have now officially agreed on a trade (so it's now a done deal). Our trades with the Red Sox and Twins are now two separate deals, and a couple of other Dodger prospects (shortstop Jeter Downs and catcher Connor Wong) are now also going to the Red Sox.

Update (2/09/20): The Dodgers also get another prospect and a draft pick from the Twins, and (according to David Schoenfield) the trade of Joc Pederson to the Angels (which apparently was contingent on the trade for Betts) appears to be a casualty of the delay in finalizing the trade for Betts.

Monday, February 03, 2020

"Online Reactions to the 2017 ‘Unite the Right’ Rally in Charlottesville: Measuring Polarization in Twitter Networks Using Media Followership"

A new paper of mine came out in final form a few days ago. Here are some details.

Title: Online Reactions to the 2017 ‘Unite the Right’ Rally in Charlottesville: Measuring Polarization in Twitter Networks Using Media Followership

Authors: Joseph H. Tien, Marisa C. Eisenberg, Sarah T. Cherng, and Mason A. Porter

Abstract: Network analysis of social media provides an important new lens on politics, communication, and their interactions. This lens is particularly prominent in fast-moving events, such as conversations and action in political rallies and the use of social media by extremist groups to spread their message. We study the Twitter conversation following the August 2017 ‘Unite the Right’ rally in Charlottesville, Virginia, USA using tools from network analysis and data science. We use media followership on Twitter and principal component analysis (PCA) to compute a ‘Left’/‘Right’ media score on a one-dimensional axis to characterize Twitter accounts. We then use these scores, in concert with retweet relationships, to examine the structure of a retweet network of approximately 300,000 accounts that communicated with the #Charlottesville hashtag. The retweet network is sharply polarized, with an assortativity coefficient of 0.8 with respect to the sign of the media PCA score. Community detection using two approaches, a Louvain method and InfoMap, yields communities that tend to be homogeneous in terms of Left/Right node composition. We also examine centrality measures and find that hyperlink-induced topic search (HITS) identifies many more hubs on the Left than on the Right. When comparing tweet content, we find that tweets about ‘Trump’ were widespread in both the Left and Right, although the accompanying language (i.e., critical on the Left, but supportive on the Right) was unsurprisingly different. Nodes with large degrees in communities on the Left include accounts that are associated with disparate areas, including activism, business, arts and entertainment, media, and politics. By contrast, support of Donald Trump was a common thread among the Right communities, connecting communities with accounts that reference white-supremacist hate symbols, communities with influential personalities in the alt-right, and the largest Right community (which includes the Twitter account FoxNews).

Note: And only now after several rounds of page proofs, right after it's too late, do I notice that the typesetters changed "Right" to "right" in the paper title, even though it is a proper noun. Well, we had plenty of chances to notice this typo that they introduced, so it's frustrating that this is another one of those that I notice immediately as soon as it's published (while not catching it in my numerous chances to see it).