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The Weird Week in Review

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Robber Writes Note on Personal Check

33-year-old Patrick Johnson was arrested on bank robbery charges after he demanded and received money from two Bank of America locations in Ocala, Florida. In both instances, he passed a note to the teller that said he had a gun. Police were able to find Johnson with the help of witnesses on the scene. Officers then noticed that both notes were written on the backs of printed checks from Johnson's personal checking account!

Vet Pulls Hook out of Shark's Mouth

A female nurse shark was struggling with a large gaff in her mouth in the Cape Byron Marine Park in New South Wales last week. Three divers set out to reach her, and were surprised to find the shark on their first dive. The 9.8-foot shark was lassoed and brought to the surface. Four men straddled the shark to restrain her while Sea World veterinarian David Blyde reached down inside to remove the hook. The operation took about two hours. See more pictures here.

World Santa Claus Congress Held in Copenhagen

136 Santas from around the globe met this week in Denmark for the annual World Santa Claus Congress. The event has been held annually for since 1957, and includes a bicycle parade, singing, and a "yula-hoop" event. See a gallery of photographs from this year's event here.

Hailstones Blast Man Off Toilet

125toilet.jpgMartin Bierbauer was on the toilet at his apartment in Eisenstadt, Austria when hundreds of thousands of hailstones exploded out of the fixture. The hailstones were from an earlier storm that blocked municipal drains. Several toilets in the building were affected in the same way.
Martin Bierbauer said: "I heard the pipes rumbling a bit, and suddenly hailstones the size of golf balls started exploding out of the toilet like it was a popcorn machine.
"There was an avalanche of ice that quickly filled the toilet, then the entire flat, and eventually the entire building."

"Lesbian" Can Legally Mean What You Think

Three residents of the Greek island Lesbos filed an injunction with a Greek court to define "Lesbians" as those who live on the island. They argued that using the word to refer to gay women was "insulting" to local residents. Lats week, a court in Athens rejected the notion, saying that gay groups in Greece and elsewhere could use the term. The plaintiffs were fined court costs, but can appeal the decision. Lesbos is the birthplace of the ancient poetess Sappho, whose poetry inspired the popular use of the term lesbian.

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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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