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A new algorithm designed at the University of Toronto could change the way we find photos among the billions on social media sites such as Facebook and Flickr.
Developed by Parham Aarabi, a professor in The Edward S. Rogers Sr. Department of Electrical & Computer Engineering, and his former Master’s student Ron Appel, the search tool uses the locations of tagged persons to quantify relationships between them, even those not tagged in any given photo.
Imagine you and your mother are pictured together, building a sandcastle at the beach. You’re both tagged in the photo quite close together. In the next photo, you and your father are eating watermelon. You’re both tagged. Because of your close ‘tagging’ relationship with both your mother in the first picture and your father in the second, the algorithm can determine that a relationship exists between those two and quantify how strong it may be.
In a third photo, you fly a kite with both parents, but only your mother is tagged. Given the strength of your “tagging” relationship with your parents, when you search for photos of your father the algorithm can return the untagged photo because of the very high likelihood he’s pictured.
“Two things are happening: we understand relationships, and we can search images better,” says Professor Aarabi.
The nimble algorithm, called relational social image search, achieves high reliability without using computationally intensive object- or facial-recognition software.
“If you want to search a trillion photos, normally that takes at least a trillion operations. It’s based on the number of photos you have,” says Aarabi. “Facebook has almost half a trillion photos, but a billion users. Our algorithm is simply based on the number of tags, not on the number of photos, which makes it more efficient to search than standard approaches.”
Currently the algorithm’s interface is primarily for research, but Aarabi aims to see it incorporated on the backend of large image databases or social networks. “I envision the interface would be exactly like you use Facebook search — for users, nothing would change. They would just get better results,” says Aarabi.
While testing the algorithm, Aarabi and Appel discovered an unforeseen application: a new way to generate maps. They tagged a few photographs of buildings around the University of Toronto and ran them through the system with a bunch of untagged campus photos. “The result we got was of almost a pseudo-map of the campus from all these photos we had taken, which was very interesting,” says Aarabi.
This work received support from the National Science and Engineering Research Council of Canada. It will be presented at the IEEE International Symposium on Multimedia Dec. 10, 2013.
Miniaturized robots that could one day function medically inside the human body are being designed by researchers in Trieste and Catalonia.
The robots of the future will be increasingly like biological organisms, with the same “softness” and flexibility as biological tissues, according to Antonio De Simone from SISSA (the International School for Advanced Studies of Trieste) and Marino Arroyo from the Polytechnic University of Catalonia, who have just published a paper in the Journal of the Mechanics and Physics of Solids, inspired by unicellular water microorganisms.
“If I think of the robots of tomorrow, what comes to mind are the tentacles of an octopus or the trunk of an elephant rather than the mechanical arm of a crane or the inner workings of a watch, said De Simone. “And if I think of microrobots, I think of unicellular organisms moving in water.
One of the aims of De Simone’s research — which has recently been awarded a European Research Council Advanced Grant of 1,300,000 euro — is to transfer the knowledge acquired in euglenids (unicellular microorganisms) to microrobotics. Microrobots may in fact carry out a number of important functions, for example for human health, by delivering drugs directly to where they are needed, re-opening occluded blood vessels, or helping to close wounds, he suggests.
To do this, these tiny robots will have to be able to move around efficiently. “Imagine trying to miniaturize a device made up of levers and cogwheels: you can’t go below a certain minimal size. Instead, by mimicking biological systems we can go all the way down to cell size, and this is exactly the direction research is taking. We, in particular, are working on movement and studying how certain unicellular organisms with highly efficient locomotion move.”
In their study, De Simone and Arroyo simulated euglenid species with different shapes and locomotion methods, based chiefly on cell body deformation and swelling, to describe in detail the mechanics and characteristics of the movements.
These devices may possibly incorporate some of the features of the nanorobots (“nanobots”) conceptually designed by Robert A. Freitas, Jr.
Abstract of Journal of the Mechanics and Physics of Solids paper
We examine a novel mechanism for active surface morphing inspired by the cell body deformations of euglenids. Actuation is accomplished through in-plane simple shear along prescribed slip lines decorating the surface. Under general non-uniform actuation, such local deformation produces Gaussian curvature, and therefore leads to shape changes. Geometrically, a deformation that realizes the prescribed local shear is an isometric embedding. We explore the possibilities and limitations of this bio-inspired shape morphing mechanism, by first characterizing isometric embeddings under axisymmetry, understanding the limits of embeddability, and studying in detail the accessibility of surfaces of zero and constant curvature. Modeling mechanically the active surface as a non-Euclidean plate (NEP), we further examine the mechanism beyond the geometric singularities arising from embeddability, where mechanics and buckling play a decisive role. We also propose a non-axisymmetric actuation strategy to accomplish large amplitude bending and twisting motions of elongated cylindrical surfaces. Besides helping understand how euglenids delicately control their shape, our results may provide the background to engineer soft machines.
Per Lindstrand, the engineer who broke numerous ballooning records with Richard Branson, is hoping to develop a 1km-tall inflatable chimney that can capture energy from the sun, The Engineer reports.
The tower uses rising air heated by the sun to drive turbines. It could provide an alternative to photovoltaic generation in remote areas of seismic activity where maintenance of power lines or solar panels would be difficult.
Lindstrand is consulting with ALMA Observatory in Chile’s Atacama desert, which is looking for a greener alternative to its gas and diesel generators and that was more robust than solar panels.Lindstrand believes inflatable structures have advantages over concrete, metal or glass models, particularly in desert locations, where the fine sand would clog solar panels, and over metal, which is more complex to fabricate.
To generate enough power for the ALMA observatory, the chimney will need to be 1km high with a 7km-radius canopy at its base to heat the air to drives the turbines.
Lindstrand said that a similar-sized concrete chimney would cost around $750 million but that an inflatable one could be made for as little as $20 million.
This should create a 130MW power station with a capacity factor of 24.7 per cent (much higher than solar PV and on a par with wind turbines), producing 281GWh of electricity a year, according to Patrick Cottam, the Lindstrand Technologies engineer who is designing a 3.5m prototype chimney.
The challenge in constructing a 1km-tall chimney will be in finding a material strong enough to support the high tension forces at the base, with the right flexibility to withstand movement in the wind and the chemical properties to survive many years of exposure to the sun’s ultraviolet light, said Cottam.
H/T Max Gigawatt