Innovation and Technology Weekly – No. 19, 2013

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Issue 19, 2013

This week's headlines:

Light breaks up to cloak gaps in time
June 05, 2013

A device that manipulates light to open up small gaps in time has crept toward implementation outside the lab and could soon improve security over fibre-optic lines or improve data streaming rates.

Last year researchers from Cornell University developed a cloak that hides events during a fixed time interval. A specially designed lens split light beams passing through a fibre into two segments. The trailing segment of light lagged behind the leading one by up to 50 trillionths of a second, creating a gap of total darkness between them. When the team fired a laser at the fibre, the laser shot was undetectable because it had passed through the 50-picosecond interval of invisibility. Finally, the researchers set up another lens to stitch the light segments back together, ensuring that the light beam emerged from the fiber looking exactly as it did at the start.

After reading the Cornell study, Joseph Lukens at Purdue University realized he could improve the technique. He designed an apparatus using off-the-shelf equipment that forced light to interfere and create repeating gaps of darkness at fixed temporal intervals. Each 40-picosecond gap was sandwiched between about 40 picoseconds of light, meaning that the time cloak was on roughly half the time.

Lukens’ study demonstrates how a time-cloaking device could eventually allow law enforcement or the military to prevent a nefarious person from communicating without the person’s realising it. Just as the time gap in the Cornell experiment made the laser undetectable, the gaps created by Lukens’s cloak can conceal digital data. Lukens’ team tried to inject an electrical signal of 1s and 0s into the fibre, a task that would be no problem without a cloak, but the message never got encoded into the light beam. The receiver would assume that no message had been sent.

Full story: Science News / Nature Back to top

Why innovation thrives in cities
June 04, 2013

Researchers from the MIT Media Laboratory’s Human Dynamics Lab propose a new explanation for that 'superlinear scaling': Increases in urban population density give residents greater opportunity for face-to-face interaction. The new paper builds on previous work by the same group, which showed that increasing employees' opportunities for face-to-face interaction could boost corporations' productivity.

In those studies, the researchers outfitted employees of a bank, of an IT consulting firm, and of several other organizations with tiny transmitters that actively measured the time the wearers spent in each other's presence. Obviously, that approach wouldn't work in a study of the entire populations of hundreds of cities.

So now researchers looked at a host of factors that could be used to predict 'social-tie density', or the average number of people that each resident of a city will interact with in person. Those factors include things like the number of call partners with whom a cellphone user will end up sharing a cell tower, instances of colocation with other users of location-tracking social-networking services like Foursquare, and the contagion rates of diseases passed only by intimate physical contact.

The availability of different types of data varied across the hundreds of cities in the US and Europe that the researchers considered. But the team concocted a single formula that assigned each city a social-tie-density score on the basis of whatever data was available. That score turned out to be a very good predictor of each city’s productivity, as measured by both gross domestic product and patenting rates.

Full story: MIT / Nature Communications Back to top

Remembering objects lets computers learn like a child
June 05, 2013

Always seeing the world with fresh eyes can make it hard to find your way around. Giving computers the ability to recognise objects as they scan a new environment will let them navigate much more quickly and understand what they are seeing.

Scienstist from1 Imperial College London have added object recognition to a computer vision technique called simultaneous location and mapping (SLAM). A SLAM-enabled computer has a camera to orient itself in new surroundings as it maps them. SLAM builds up a picture of the world out of points and lines and contours. In an office, say, chairs and desks would emerge from the room like hills and valleys in a landscape.

But in the new system, called SLAM++, the computer constantly tries to match the points and lines it sees to objects in its database. As soon as it finds a shape it can identify – often after seeing only a part of it – that area of the map can be filled in. Currently, the database is prepared by hand, but the next version will allow the system to add new objects itself as it encounters them.

The database also lists the properties of the stored objects. So when the computer recognises a chair, it will know what they are used for, how much they typically weigh, and which way up they go. This knowledge will help digital avatars interact with the real world in augmented reality applications, for example.

Full story: New Scientist Back to top

Volvo tests electric roads
June 03, 2013

Battery conundrums continue to be a major road block for electric vehicles. They are big, heavy, limit range, and although there is less pollution coming out of an EV’s tailpipe, charging the battery still utilises fossil fuels. While many firms are focused on solving these battery problems, Volvo Group is taking a different approach: get rid of the battery all together.

The company envisions a future where electric trucks and buses harvest power from lines built directly into the surface of the road, rather than a bulky on-board battery. Although we hsve seen this concept before, Volvo has already gone beyond talk and is actively testing it at a 400-meter long track at its testing facility in Hällered outside Gothenburg.

At its test track, Volvo has built two power lines into the surface of the road. A current collector in contact with the power lines is located on the truck. Although initial results are promising, many years remain before electric roads move out of the experimental phase. The delay may actually be a blessing in disguise, however. Perhaps by the time the current collector, electric motor and control systems are perfected, most of the electricity running through the grid will come from renewable sources rather than fossil fuels.

Full story: TG Daily Back to top

UV rays in your fridge could keep strawberries perfect
June 06, 2013

Tired of fresh strawberries turning fuzzy after a few days in the refrigerator? Bathing them in dim ultraviolet light from LEDs could more than double their storage life, while preserving compounds that give the fruit their colour and health benefits.

Strawberries must be picked when nearly ripe, and the fruit is prone to fungal diseases that limit its shelf life. Previous experiments have shown that fruit lasts longer when exposed to bright flashes of germicidal ultraviolet light soon after harvest. However, the UV light used is hazardous to humans. What's more, the bulbs that produce it work poorly at refrigerator temperatures, and require careful handling as they contain mercury.

Steven Britz of the US Department of Agriculture's Food Components and Health Laboratory in Beltsville, Maryland, wondered if recently developed ultraviolet LEDs would be a better alternative. Based on materials similar to those used in Blu-ray disc players, the UV-LEDs work well in chilly conditions, and the wavelengths they put out are less hazardous than those from mercury bulbs. They are also efficient, so need little power to run.

With engineers from LED manufacturer Sensor Electronic Technology in Columbia, South Carolina, Britz built a prototype to illuminate store-bought strawberries in a cooler at 95%. After nine days – more than double the refrigerator life of untreated fruit – the strawberries showed no mould, retained most of their moisture, and had lost few of the health-promoting anthocyanin compounds that give them their colour.

Full story: New Scientist Back to top

Photo of your face is all it takes to predict your BMI
June 05, 2013

There's a lot you can tell from a face – and now there's one more thing: body mass index. Software that can predict your BMI from a snapshot of your face could turn a simple headshot into a revealing portrait of your build, and even your risk of certain diseases.

BMI is a standard health metric that's equal to a person's weight divided by the square of their height. Someone with a BMI over 30 is acknowledged as obese and below 18.5 as underweight.

How we perceive someone's weight based on images of their face is strongly correlated with actual body weight and associated health risks. Building on that knowledge, researchers at West Virginia University in Morgantown have now produced an algorithm that can analyse a mugshot and predict that person's BMI.

The software assesses seven weight-related components in a face image, including the ratios of cheekbone width to jaw width, face length to cheekbone width and the average distance between eyebrow and eye. They then ran the program across images of 14,500 faces of people with known BMIs. The predicted BMIs were mostly within two or three points of the person's actual BMI. The researchers thingk that tweaking the software to analyse more facial features should improve the results.

Full story: New Scientist Back to top