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Mad men, vagrants and secret symbols

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I'm the type of person who doesn't like to come into a new TV series in the middle. Not that I watch much TV, but when I do, I'm pretty loyal from the pilot onward and don't like wondering what I missed. Of course, with iTunes, it's now possible to download episodes of certain shows that have deals with Apple for less than the price of a gallon of gas. So it's been with AMC's new series Mad Men.

With Baby Jack taking up so much of our lives, my wife and I missed the first half-dozen episodes. In fact, I didn't know anything about the show until I heard some colleagues discussing it at the office over lunch one day.

If you haven't checked it out yet, do! It's set in an advertising agency in NYC during the early1960s and features one of the best-looking, most authentic sets in recent memory. Danish teak in every room, ashtrays and cigarettes in every scene, and wonderful attention to detail in the costumes, musical selections, and, sadly, the characters' treatment of women and minorities. Even the pacing of the show matches that of a show made in 1960 vis-à-vis today. (Which might be a turn off to those raised on Aaron Sorkin, but not me.)

Created by a former Sopranos producer/writer named Matthew Weiner, the show uses flashbacks much the way David Chase did for Tony Soprano to help fill in the backstory regarding the childhood of its protagonist—in this case, Don Draper, the creative director for Sterling Cooper advertising agency.

Other than plugging the show with the hopes of boosting its ratings and, therefore, doing my part to help secure a re-order for next season, I wanted to write about something I learned on a recent episode (gotta love shows that work all kinds of cool, accurate trivia into their storylines). I had no idea, but apparently there's a code of symbols that vagrants once relied on (and perhaps still do) when stopping for the night. With a piece of chalk, or a knife, they'd etch a symbol like the ones you see below into a fence post or a backdoor to alert future tramps who might be passing through. The images below come from this site, which has many more for the mildly curious. For the very curious, I really do urge you to catch the reruns on AMC or head over to iTunes and download the episodes. I'd be surprised if you didn't like "˜em.

Anyone agree? Disagree?


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iStock // Ekaterina Minaeva
Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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Name the Author Based on the Character
May 23, 2017
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