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YouTube / Gates Foundation

6 People Who Make a Difference

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YouTube / Gates Foundation

Not everyone's job is glamorous. But even toilet cleaners make a tremendous difference in their communities—keeping a public toilet clean can mean the difference between life and death. Here are six people who take pride in their work helping others.

1. Hanna Konadu - Child Vaccinator

In Ghana, Hanna Konadu provides community health services to mothers and children. Last year she vaccinated 10,000 children (!). Because of workers like Konadu, Ghana has improved its immunization coverage rate to more than 90 percent, protecting kids against measles, pneumonia, polio, and other diseases.

2. Jean Pierre Kandety - Contraceptive Delivery Man

In Dakar, Senegal, Jean Pierre Kandety delivers contraceptive supplies to clinics throughout the city. This is crucial, because just 13% of women aged 15-49 are using protection, and Senegal is in the world's top 50 countries when it comes to under-5 child mortality. Here's how he thinks about his job:

3. Rose George - Journalist

Based in the UK, Rose George reports on issues we don't often think about. In 2013, she gave a TED Talk discussing her work covering sanitation and the diarrhea crisis—a phrase that might make some giggle, but not when you realize how deadly diarrhea can be: it's the second-biggest killer of children worldwide.

In a world where an estimated 2.5 billion people don't have a safe place to relieve themselves, George highlights a crucial issue. Have a look:

George also wrote the book The Big Necessity: The Unmentionable World of Human Waste and Why It Matters.

4. Dr. Mathew Varghese - Orthopedic Surgeon

In Delhi, India, Dr. Mathew Varghese runs India's last polio ward. Just five years ago, India accounted for about half of the world's wild polio cases. Today, India has been certified as polio-free. In this short video, Varghese shows us what polio looks like for those who already contracted the disease.

5. Swapnil Chaturvedi - Toilet Cleaner

In Pune, India, Swapnil Chaturvedi cleans toilets, providing "awesome sanitation services for the urban poor." He is on the ground addressing sanitation issues—and he does it because of his daughter. Have a look at his inspiring story:

For more on PoopGuy, see our profile from last month.

6. Moushumi - Parent Educator

In India, a woman named Moushumi works to help parents use everyday tools to make childbirth safer. She travels from village to village, working with PATH Sure Start to help mothers and fathers care for their children before, during, and after birth. Here's how she thinks about her work—and her own child:

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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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