21/12/2011

 athira

Brave the mall maze with indoor positioning systems

DO YOU ever find yourself in a vast shopping centre or airport wishing you could use something like GPS to help you find your way? That could soon happen with the development of indoor versions of the system.

"Thank the furniture gods," was one tweeted response to news that IKEA's cavernous couch emporia are getting a smartphone-based indoor positioning system (IPS) developed by Google.

The search giant is not alone: Nokia, Sensewhere, based in Edinburgh, UK, and Cambridge Silicon Radio, also in the UK, are all getting in on the IPS act. Each announced offerings last week that use slightly different technological approaches to stop people getting lost indoors.

The new systems are needed as GPS signals can't reliably be received in a building. Google's IPS offering is an extension of its Maps software, which uses GPS, cellphone and Wi-Fi signals to calculate where a user is outdoors.

To ensure a person walking from the street into a large indoor space gets a seamless experience, the latest version of Maps drops the GPS once inside and measures the signal strength from Wi-Fi routers and cellphone towers to triangulate their location. Users of Android-equipped phones can now use the service in number of major airports, branches of Macy's, Bloomingdale's, Home Depot and Ikea - plus the giant Mall of America in Minneapolis, Minnesota. Wi-Fi signals emanating from businesses throughout a building lets the system work out where you are to within 5 metresNokia's version of IPS, not yet available to consumers, aims for even greater precision. The firm litters buildings of interest with Bluetooth-based radio beacons that switch phones running mapping apps based on GPS to using Bluetooth 4.0 signals once they walk indoors. Because the beacons are at fixed sites and have a short range, they can work out your position to within 30 centimetres - enough to "bookmark" a jacket in a shop window and browse back to it later.

Another approach to accuracy is being taken by Sensewhere, whose smartphone-based IPS is being tested in Edinburgh's Gyle shopping mall. The company says that the main problem with relying on maps of Wi-Fi networks to find your position is that routers get disconnected, thrown out or switched off. To get round this, Sensewhere's app frequently files reports to its database on how the radio environment has changed, meaning its IPS maps "automatically self-improve" says a spokesperson.

A further way to boost IPS accuracy is to use data from phone accelerometers to calculate how far someone has moved since the last radio fix. On 2 November, Cambridge Silicon Radio launched a line of microchipsthat do just that, adding inertial data to that gleaned from Wi-Fi and cellphones. The firm hopes the chips will make IPS adoption by phone makers more likely.

The challenges for all these IPS vendors, says Bob Cockshott, a GPS expert with the UK's National Physical Laboratory in Teddington, is to ensure that physical changes to the environment don't ruin position fixes. "The big issue for indoor positioning is that once you have mapped the radio [signals] in a space, just doing something as simple as moving a metal filing cabinet could change the paths the radio waves take - and that will lower accuracy."

AJAY PAUL

Software glitch in Lumia will have minimal impact in India: Nokia

The discovery of software-related glitch in some units of Lumia 800, the Windows-based phone recently launched by Nokia, will not have any major impact in India, asserts the company.

“India impact will be minimal since we just started shipping. Therefore, if a consumer buys a Nokia Lumia 800 today, there is absolutely no impact. Nokia will go the extra mile to delight their consumers, especially with a flagship product like Lumia 800,” Nokia asserted in a release on Tuesday.

The release comes in the wake of reported instances where the pre-loaded diagnostics tool in the Nokia Lumia 800 was showing lower than expected levels of full battery charge capacity.

http://www.thehindu.com/business/companies/article2732674.ece

reeshma ramesan

Sony has unveiled a paper-powered battery prototype in Japan.

The technology generates electricity by turning shredded paper into sugar which in turn is used as fuel.If brought to market, the innovation could allow the public to top up the power of their mobile devices using waste material.The team behind the project said such bio-batteries are environmentally friendly as they did not use harmful chemicals or metals.The Japanese electronics giant showed off its invention at the Eco-Products exhibition in Tokyo last week.Employees invited children to drop piece of paper and cardboard into a liquid made up of water and enzymes, and then to shake it. The equipment was connected to a small fan which began spinning a few minutes later.

Learning from nature

The process works by using the enzyme cellulase to decompose the materials into glucose sugar. These were then combined with oxygen and further enzymes which turned the material into electrons and hydrogen ions.The electrons were used by the battery to generate electricity. Water and the acid gluconolactone, which is commonly used in cosmetics, were created as by-products.Researchers involved in the project likened the mechanism to the one used by white ants and termites to digest wood and turn it into energy.Their work builds on a previous project in which they used fruit juice to power a Walkman music player."Using a 'fuel' as simple as old greetings cards - the sort of cards that millions of us will be receiving this Christmas - the bio battery can deliver enough energy to power a small fan," said Yuichi Tokita, senior researcher at Sony's Advanced Material Research Lab."Of course, this is still at the very early stages of its development, but when you imagine the possibilities that this technology could deliver, it becomes very exciting indeed."

Eco-friendly

While the battery is already powerful enough to run basic music players, it is still falls far short of commercially sold batteries.The environmental campaign group Greenpeace welcomed the development."The issue that we always have with battery technology is the toxic chemicals that go into making them and recycling batteries is also complicated," John Sauven, executive director of Greenpeace UK."Any way to provide a greener technology could be a potential magic bullet. So from that point of view this is interesting, and I think it's fantastic that companies like Sony are looking to make the generation of energy more environmentally friendly."Sony's engineers are not the only ones exploring the concept of paper-based batteries.In 2009 a team of Stanford University scientists revealed they were working on a battery created by coating sheets of p http://www.technologyreview.in/blog/arxiv/27420/?p1=Aaper with ink made of carbon nanotubes and silver nanowires. They said their work might ultimately lead to a device capable of lasting through 40,000 charge-discharge cycles.

Mithun Mathew

IBM Watson

Watson is an artificial intelligence computer system capable of

answering questions posed in natural language, developed in IBM's

DeepQA project by a research team led by principal investigator David

Ferrucci. Watson was named after IBM's first president, Thomas J.

Watson.

In 2011, as a test of its abilities, Watson competed on the quiz show

Jeopardy!, in the show's only human-versus-machine match-up to date.

In a two-game, combined-point match, broadcast in three Jeopardy!

episodes February 14–16, Watson beat Brad Rutter, the biggest all-time

money winner on Jeopardy!, and Ken Jennings, the record holder for the

longest championship streak (75 days). Watson received the first prize

of $1 million.

Watson consistently outperformed its human opponents on the game's

signaling device, but had trouble responding to a few categories,

notably those having short clues containing only a few words. For each

clue, Watson's three most probable responses were displayed by the

television screen. Watson had access to 200 million pages of

structured and unstructured content consuming four terabytes of disk

storage, including the full text of Wikipedia. Watson was not

connected to the Internet during the game.

Johny James

Starting in January 2012, Facebook will be featuring ads or sponsored stories in the main news feed in the web version of the social networking site. Facebook had stopped displaying ads in the main news feed long back in 2008, thus the new move is likely to be a big boost for the advertisers.

"Starting early next year, we will gradually begin showing Sponsored Stories in News Feed," a spokesperson for Facebook said in a statement. "Our goal is to do this thoughtfully and slowly. We hope to show people no more than one Sponsored Story in their News Feeds per day and the story will be clearly labeled.”

The sponsored stories that would appear in the News Feed would be based on stories or Pages that you and your friends have already liked. The new move is aimed at engaging more users with the ads and sponsored items on the social networking. Users may not opt out of seeing sponsored items in the news feed, though they can unsubscribe certain ads. However, users may not remove ads of the Page they have already liked.

Facebook's new move is likely to trigger backlash from many users, who wish not to see the ads or have their news feed. Facebook was recently slammed by the US' FTC for its privacy policies. This is why the company is looking to integrate the ads slowly. Moreover, Facebook is likely to ensure the sponsored stories look similar to the regular news feed content, which will not disturb several users.
Arun Jose

How 3-D Photovoltaics Could Revolutionize Solar Power

Replacing flat panels with three dimensional structures can significantly change the economics of solar power generation, say engineers

Read full news at

 http://www.technologyreview.in/blog/arxiv/27420/?p1=A
ANTO VARGHESE

Stall...

In fluid dynamics a stall is a reduction in the lift coefficient generated by a foil as angle of attack(AOA) increases. This occurs when the criticalAOA of the foil is exceeded. The critical angle of attack is typically about 15 degrees, but it may vary significantly depending on the fluid, foil, and Reynolds number.

Stalls in fixed-wing flight are often experienced as a sudden reduction in lift as the pilot increases angle of attack and exceeds the critical angle of attack (which may be due to slowing down below stall speed in level flight). A stall does not mean that the engine(s) have stopped working, or that the aircraft has stopped moving — the effect is the same even in an unpowered glider aircrsft. Vectored thrust in manned and unmanned aircraft is used to surpass the stall limit, thereby giving rise to post stalltechnology.

Because stalls are most commonly discussed in connection with aviation, this article discusses stalls as they relate mainly to aircraft, in particular fixed wing aircraft. The principles of stall discussed here translate to foils in other fluids as well.

Stall warning and safety devices...

   A stall strip is a small sharp-edged device that, when attached to the leading edge of a wing, encourages the stall to start there in preference to any other location on the wing. If attached close to the wing root, it makes the stall gentle and progressive; if attached near the wing tip, it encourages the aircraft to drop a wing when stalling.

  A stall fence is a flat plate in the direction of the chord to stop separated flow progressing out along the wing.

  An Angle-Of-Attack (AOA) Indicator, also called a Lift Reserve Indicator, is a pressure differential instrument that integrates airspeed and angle of attack into one instantaneous, continuous readout. An AOA indicator provides a visual display of the amount of available lift throughout its slow speed envelope regardless of the many variables that act upon an aircraft. This indicator is immediately responsive to changes in speed, angle of attack, and wind conditions, and automatically compensates for aircraft weight, altitude, and temperature.An angle of attack limiter or an "alpha" limiter is a flight computer that automatically prevents pilot input from causing the plane to rise over the stall angle. Some alpha limiters can be disabled by the pilot.