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YouTube / Gates Foundation

Meet PoopGuy, India's Toilet Hero

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YouTube / Gates Foundation

Swapnil Chaturvedi cleans toilets for a living, and goes by the nickname "PoopGuy." He works in the slums of Pune, India, bringing a much-needed resource to the locals: clean toilets. In a place where one toilet can serve 1,000 people every day, keeping things clean is a serious challenge.

Here's a video telling, in Chaturvedi's own words, what it's like to be PoopGuy. Below the video, some more on the man and his mission. A sample quote: "We can live without Facebook, we can live without smartphones. But we cannot live without relieving ourselves."

Chaturvedi moved from India to the US in 2001, for college. After graduation, he worked as a software engineer in the US. He married, had a baby, and was living the American Dream. But after a visit to his family in India, he realized that his true calling was in helping the poor in his home country. Here's his story, in his own words:

In June 2007, I became the father of a beautiful girl child. When she was 3 months old, we were visiting India after a gap of over 4 years. I was so excited to meet my family and to see the “progress” my parents had been talking about. But what I saw completely changed my life.

On the one hand there were big shopping malls and on the other there were these slums all over the city (with kids defecating in [the] open). Maybe it was because I had lived in US long enough to gain an outsider’s perspective, but it was as if my blindfolds had been removed and I was seeing things for the first time. That night, for the first time in my life, I asked questions that guided me towards my purpose:

• What does GDP mean for a woman who has to spend over an hour to find a place to defecate?

• What does it mean to live in a slum right beside high rise buildings?

• What does it cost to live in such deplorable conditions?

• Who is responsible for providing the most basic services to the urban poor?

We went back to the US in a month, but the work that excited me earlier, did not appeal to me anymore.

Chaturvedi then founded Samagra Sanitation in 2011, and has been working ever since to provide "awesome sanitation services for the urban poor." Samagra recently started an Indiegogo campaign, raising money to provide community toilets for 50,000 people. That's awesome sanitation in action!

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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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