Wednesday, 27 February 2013
Memristors may lead to Artificial Brains
Bielefeld physicist Andy Thomas takes nature as his model
Scientists have long been dreaming about building a computer that would work like a brain. This is because a brain is far more energy-saving than a computer, it can learn by itself, and it doesn’t need any programming. Privatdozent [senior lecturer] Dr. Andy Thomas from Bielefeld University’s Faculty of Physics is experimenting with memristors – electronic microcomponents that imitate natural nerves. Thomas and his colleagues proved that they could do this a year ago. They constructed a memristor that is capable of learning. Andy Thomas is now using his memristors as key components in a blueprint for an artificial brain. He will be presenting his results at the beginning of March in the print edition of the prestigious Journal of Physics published by the Institute of Physics in London.
Scientists have long been dreaming about building a computer that would work like a brain. This is because a brain is far more energy-saving than a computer, it can learn by itself, and it doesn’t need any programming. Privatdozent [senior lecturer] Dr. Andy Thomas from Bielefeld University’s Faculty of Physics is experimenting with memristors – electronic microcomponents that imitate natural nerves. Thomas and his colleagues proved that they could do this a year ago. They constructed a memristor that is capable of learning. Andy Thomas is now using his memristors as key components in a blueprint for an artificial brain. He will be presenting his results at the beginning of March in the print edition of the prestigious Journal of Physics published by the Institute of Physics in London.
A nanocomponent that is capable of learning: The Bielefeld memristor built into a chip here is 600 times thinner than a human hair.
Like synapses, memristors learn from earlier impulses. In their case, these are electrical impulses that (as yet) do not come from nerve cells but from the electric circuits to which they are connected. The amount of current a memristor allows to pass depends on how strong the current was that flowed through it in the past and how long it was exposed to it.
Andy Thomas explains that because of their similarity to synapses, memristors are particularly suitable for building an artificial brain – a new generation of computers. ‘They allow us to construct extremely energy-efficient and robust processors that are able to learn by themselves.’ Based on his own experiments and research findings from biology and physics, his article is the first to summarize which principles taken from nature need to be transferred to technological systems if such a neuromorphic (nerve like) computer is to function. Such principles are that memristors, just like synapses, have to ‘note’ earlier impulses, and that neurons react to an impulse only when it passes a certain threshold.
Dr. Andy Thomas has summarized the technological principles that need to be met when constructing a processor based on the brain.
If the neutral bell-ringing stimulus is introduced at the same time as the food stimulus, the dog will learn. The control mechanism in the brain now assumes that the nerve cells transporting the neutral stimulus (bell ringing) are also responsible for the reaction – the link between the actually ‘neutral’ nerve cell and the ‘salivation’ nerve cell also becomes stronger. This link can be trained by repeatedly bringing together the stimulus eliciting a reflex response and the neutral stimulus. ‘You can also construct such a circuit with memristors – this is a first step towards a neuromorphic processor,’ says Andy Thomas.
‘This is all possible because a memristor can store information more precisely than the bits on which previous computer processors have been based,’ says Thomas. Both a memristor and a bit work with electrical impulses. However, a bit does not allow any fine adjustment – it can only work with ‘on’ and ‘off’. In contrast, a memristor can raise or lower its resistance continuously. ‘This is how memristors deliver a basis for the gradual learning and forgetting of an artificial brain,’ explains Thomas.
Original publication:
Andy Thomas, ‘Memristor-based neural networks’, Journal of Physics D: Applied Physics, http://dx.doi.org/10.1088/0022-3727/46/9/093001, released online on 5 February 2013, published in print on 6 March 2013.
For further information in the Internet, go to:
www.spinelectronics.de
Contact:
Dr. Andy Thomas, Bielefeld University
Faculty of Physics
Telephone: 0049 521 106-2540
Email: andy.thomas@uni-bielefeld.de
link for this article
Sunday, 24 February 2013
NASA Rover Confirms First Drilled Mars Rock Sample
On 20 February 2013 NASA's Mars rover Curiosity relayed new images that confirm it has successfully obtained the first sample ever collected from the interior of a rock on another planet. No rover has ever drilled into a rock beyond Earth and collected a sample from its interior.
Transfer of the powdered-rock sample into an open scoop was visible for the first time in images received Wednesday at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
"Seeing the powder from the drill in the scoop allows us to verify for the first time the drill collected a sample as it bore into the rock," said JPL's Scott McCloskey, drill systems engineer for Curiosity. "Many of us have been working toward this day for years. Getting final confirmation of successful drilling is incredibly gratifying. For the sampling team, this is the equivalent of the landing team going crazy after the successful touchdown."
The drill on Curiosity's robotic arm took in the powder as it bored a 2.5-inch (6.4-centimeter) hole into a target on flat Martian bedrock on Feb. 8. The rover team plans to have Curiosity sieve the sample and deliver portions of it to analytical instruments inside the rover.
The scoop now holding the precious sample is part of Curiosity's Collection and Handling for In-Situ Martian Rock Analysis (CHIMRA) device. During the next steps of processing, the powder will be enclosed inside CHIMRA and shaken once or twice over a sieve that screens out particles larger than 0.006 inch (150 microns) across.
Small portions of the sieved sample later will be delivered through inlet ports on top of the rover deck into the Chemistry and Mineralogy (CheMin) instrument and Sample Analysis at Mars (SAM) instrument.
In response to information gained during testing at JPL, the processing and delivery plan has been adjusted to reduce use of mechanical vibration. The 150-micron screen in one of the two test versions of CHIMRA became partially detached after extensive use, although it remained usable. The team has added precautions for use of Curiosity's sampling system while continuing to study the cause and ramifications of the separation.
The sample comes from a fine-grained, veiny sedimentary rock called "John Klein," named in memory of a Mars Science Laboratory deputy project manager who died in 2011. The rock was selected for the first sample drilling because it may hold evidence of wet environmental conditions long ago. The rover's laboratory analysis of the powder may provide information about those conditions.
NASA's Mars Science Laboratory Project is using the Curiosity rover with its 10 science instruments to investigate whether an area within Mars' Gale Crater ever has offered an environment favorable for microbial life. JPL, a division of the California Institute of Technology, Pasadena, manages the project for NASA's Science Mission Directorate in Washington.
Link to NASA
Photonic Space
Saturday, 23 February 2013
Iconic NASA Image of Mercury
This colorful view of Mercury was produced by using images from the color base map imaging campaign during MESSENGER's primary mission. These colors are not what Mercury would look like to the human eye, but rather the colors enhance the chemical, mineralogical, and physical differences between the rocks that make up Mercury's surface.
Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
With Robots, Humans face ‘New Society’
Humanity came one step closer in January to being able to replicate itself, thanks to the EU’s approval of funding for the Human Brain Project. Danica Kragic, a robotics researcher and computer science professor at KTH Royal Institute of Technology in Stockholm, says that while the prospect of living among humanoid robots calls to mind terrifying scenarios from science fiction, the reality of how humans cope with advances in robotics will be more complex, and subtle.
“Robots will challenge the way we feel about machines in general,” Kragic says. “A completely different kind of society is on the way.”
The Human Brain Project will involve 87 universities in a simulation of the cells, chemistry and connectivity of the brain in a supercomputer, in order to understand the brain’s architecture, organisation, functions and development. The project will include testing brain-enabled robots.
“Will we be able to – just by the fact that we can build a brain – build a human? Why not? What would stop you?” Kragic asks.
Nevertheless, consumer-grade robots are a long way from reality, says Kragic, who in addition to serving as Director of KTH’s Centre for Autonomous Systems, is also head of the Computer Vision and Active Perception Lab.
She says that in order for robots to offer some value to households, researchers and developers will have to overcome some daunting technological challenges. Robots will have to multitask and perhaps even be programmed to have emotional capacities programmed into their logical processes, she says.
“Based on the state of the environment and what it is expected of the robot, we want the outcome action to be acceptable to humans,” she says. “Many things that we do are based not just on facts, so should machines somehow have simulated emotions, or not? Either way, it is difficult to predict how that will affect their interaction with humans.”
Kragic sees robots making a largely positive contribution to society. But they will also present some novel problems for which humans have few reference points, such as what are the social norms for interacting with robots?
“There is a discussion about robot ethics and how we should treat robots,” Kragic says. “It’s difficult to say what’s right and wrong until you are actually in the situation where you need to question yourself and your own feelings about a certain machine – and the big question is how your feelings are conditioned by the fact that you know it’s a machine, or don’t know whether it’s a machine.”
Kragic predicts that one of the most popular consumer application of robots will be as housekeepers, performing the chores that free up time for their owners. They could also take over jobs that are repetitive, such as operating buses or working in restaurants. On the other hand, the robot industry will expand and create jobs, she predicts.
As for the possibility that one day robots will turn on us – Kragic is skeptical. “A robot rebellion - that’s the ultimate science fiction scenario, right? It’s worth placing some constraints on robots, such as (author Isaac) Asimov’s Three Rules of Robotics. At the same time, we have rules as humans, which we break. No one is 100 percent safe, and the same can happen with machines.”
Human rebellion against robots is far more likely, she says, pointing out that even as society’s attitudes toward automation evolve over generations, the debate over whether humans have the right to “play God” will likely continue. “There will be people for and against it,” she says. “But what is wrong with building a human? We have been raised in a society that thinks this is wrong, that this is playing God.
“Subsequent generations could have a different view.”
By David Callahan
The Human Brain Project will involve 87 universities in a simulation of the cells, chemistry and connectivity of the brain in a supercomputer, in order to understand the brain’s architecture, organisation, functions and development. The project will include testing brain-enabled robots.
“Will we be able to – just by the fact that we can build a brain – build a human? Why not? What would stop you?” Kragic asks.
Nevertheless, consumer-grade robots are a long way from reality, says Kragic, who in addition to serving as Director of KTH’s Centre for Autonomous Systems, is also head of the Computer Vision and Active Perception Lab.
She says that in order for robots to offer some value to households, researchers and developers will have to overcome some daunting technological challenges. Robots will have to multitask and perhaps even be programmed to have emotional capacities programmed into their logical processes, she says.
“Based on the state of the environment and what it is expected of the robot, we want the outcome action to be acceptable to humans,” she says. “Many things that we do are based not just on facts, so should machines somehow have simulated emotions, or not? Either way, it is difficult to predict how that will affect their interaction with humans.”
Kragic sees robots making a largely positive contribution to society. But they will also present some novel problems for which humans have few reference points, such as what are the social norms for interacting with robots?
“There is a discussion about robot ethics and how we should treat robots,” Kragic says. “It’s difficult to say what’s right and wrong until you are actually in the situation where you need to question yourself and your own feelings about a certain machine – and the big question is how your feelings are conditioned by the fact that you know it’s a machine, or don’t know whether it’s a machine.”
Kragic predicts that one of the most popular consumer application of robots will be as housekeepers, performing the chores that free up time for their owners. They could also take over jobs that are repetitive, such as operating buses or working in restaurants. On the other hand, the robot industry will expand and create jobs, she predicts.
As for the possibility that one day robots will turn on us – Kragic is skeptical. “A robot rebellion - that’s the ultimate science fiction scenario, right? It’s worth placing some constraints on robots, such as (author Isaac) Asimov’s Three Rules of Robotics. At the same time, we have rules as humans, which we break. No one is 100 percent safe, and the same can happen with machines.”
Human rebellion against robots is far more likely, she says, pointing out that even as society’s attitudes toward automation evolve over generations, the debate over whether humans have the right to “play God” will likely continue. “There will be people for and against it,” she says. “But what is wrong with building a human? We have been raised in a society that thinks this is wrong, that this is playing God.
“Subsequent generations could have a different view.”
By David Callahan
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