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# Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning

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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There’s a new phone scam that could affect you, according to Washington’s KIRO 7 News. In addition to keeping your eyes open for calls that come from area codes like 473 or involve people claiming to be Equifax representatives, you now have to watch out for your own phone number.

Scammers are manipulating your phone’s caller ID to make it look like you’re getting a call from your own phone number, then posing as someone from a wireless carrier like AT&T or Verizon. They tell whoever answers the phone that their account has been flagged for security reasons, then ask for the last four digits of that person’s Social Security number. The FCC has been aware of these scams for at least two years, but they seem to be ramping up once again.

In general, you shouldn’t give out any part of your Social Security number over the phone on an incoming call. If you’re suspicious, you can always call your carrier back using the official customer service phone number on their website or on your bill. But it’s best not to pick up at all. If you receive a call from your own number, don’t answer or press any buttons. Instead, file a complaint with the FCC.

[h/t KIRO 7 News]

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Samsung’s Star Wars Vacuums Offer Everything You Want in a Droid
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Hate housecleaning but love Star Wars? Samsung’s got the solution. In anticipation of December’s Star Wars: The Last Jedi, the newest film in the Star Wars saga, Samsung has transformed a limited number of its VR7000 POWERbot robot vacuum cleaners into two familiar faces from George Lucas’s legendary space opera: a Stormtrooper and Darth Vader (which comes with Wi-Fi connectivity and a remote control).

In order to create a unique device that would truly thrill Star Wars aficionados, Samsung consulted with fans of the film throughout each stage of the process. The result is a pair of custom-crafted robo-vacuums that fill your home with the sounds of a galaxy far, far away as they clean (when you turn Darth Vader on, for example, you'll hear his iconic breathing).

“We are very pleased to be part of the excitement leading up to the release of The Last Jedi and to be launching our limited edition POWERbot in partnership with Star Wars fans,” B.S. Suh, Samsung’s executive vice president, said in a press statement. “From its industry-leading suction power, slim design, and smart features, to the wonderful character-themed voice feedback and sound effects, we are confident the Star Wars limited edition of the VR7000 will be a big hit.”

Be warned that this kind of power suction doesn’t come cheap: while the Stormtrooper POWERbot will set you back \$696, the Darth Vader vacuum retails for \$798. Who knew the Dark Side was so sparkling clean?

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