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Heavy Rain Heads for California—and the Oroville Dam

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The Oroville Dam spillway releases 100,000 cubic feet of water per second down the main spillway in Oroville, California on February 13, 2017. Image Credit: Josh Edelson/AFP/Getty Images

California is bracing for a life-threatening and potentially historic storm today, February 17, with the arrival of some of the nastiest weather to hit the state in many years. Conditions will go downhill in a hurry through the day as the dreary slog of driving rains, gusty winds, and intense mountain snows blankets the Golden State to begin the weekend.

The latest forecasts from the National Weather Service paint a bleak picture for California and its sprawling countryside. A sustained thump of heavy rain will cover the state during the day on Friday, but the system will begin to pick up steam as it approaches shore closer to nightfall. Heavy rain and strong winds don't seem like too big of a deal to most of us around the country, but California, with its population of around 39 million, is home to more people than 22 other states combined. Any major weather event that affects such a large segment of the population will create huge problems, especially in such a disaster-prone region of the country.

The Weather Prediction Center's forecast rainfall between February 17 and February 24, 2017. Image Credit: Dennis Mersereau

Several inches of rain are possible just about everywhere in California save for the mountains, where the precipitation will fall as many feet of snow, and the southern half of the Central Valley, where the Coast Ranges will block rain from reaching the low-lying center of the state in a phenomenon known as a rain shadow. The heaviest rain will fall in southern California near Los Angeles, where up to six inches of rain are possible in the more intense showers and thunderstorms that develop.

Rainfall totals could reach record territory in L.A., where this storm could make today one of the 10 wettest days ever recorded at Los Angeles International Airport, and it could come close to the top of the list in downtown L.A. The storm system causing all of the trouble could rank among some of the strongest low-pressure systems ever recorded off the coast of California; some weather models are predicting a minimum central pressure lower than 990 millibars—a pressure you'd expect to find in a weak hurricane.

Flash flooding will be a major concern in areas that experience sustained heavy rainfall. The National Weather Service's latest assessment of the flash flood risk in California shows that rainfall rates of only around one inch of rain per hour could lead to flash flooding. The threat for flooding from this storm is compounded by multiple factors that many other parts of the United States don't have to worry about, including rough terrain, burned ground from wildfires, and the fact that the soil is still recovering from the years-long drought that's just now starting to wane. These natural factors, in addition to urban sprawl, limit how quickly rainwater can run off into sewage systems and natural waterways.

Areas that suffered under an immense drought for most of the past decade wished for rain every winter, but this winter's steady rains have been too much of a good thing. Not only do residents now have to worry about flash flooding and mudslides, but folks who live downstream of the Oroville Dam have some extra concerns. Recent rains pushed Lake Oroville, situated north of Sacramento, California, beyond its capacity, sending water cascading down its two spillways. Tens of thousands of people had to evacuate last week when the dam's emergency spillway came perilously close to failing due to water eroding the soil and rock near the structure. The lake's water level has slowly receded in the days since, but this rainstorm could push water back to the same dangerous level we saw just a couple of days ago.

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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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Opening Ceremony
These $425 Jeans Can Turn Into Jorts
May 19, 2017
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Opening Ceremony

Modular clothing used to consist of something simple, like a reversible jacket. Today, it’s a $425 pair of detachable jeans.

Apparel retailer Opening Ceremony recently debuted a pair of “2 in 1 Y/Project” trousers that look fairly peculiar. The legs are held to the crotch by a pair of loops, creating a disjointed C-3PO effect. Undo the loops and you can now remove the legs entirely, leaving a pair of jean shorts in their wake. The result goes from this:


Opening Ceremony

To this:


Opening Ceremony

The company also offers a slightly different cut with button tabs in black for $460. If these aren’t audacious enough for you, the Y/Project line includes jumpsuits with removable legs and garter-equipped jeans.

[h/t Mashable]