New Cognitive Robotics Lab Tests Theories of Human Thought

"The real world has a lot of inconsistency that humans handle almost without noticing -- for example, we walk on uneven terrain, we see in shifting light," said Professor Vladislav Daniel Veksler, who is currently teaching Cognitive Robotics."With robots, we can see the problems humans face when navigating their environment."

Cognitive Robotics marries the study of cognitive science -- how the brain represents and transforms information -- with the challenges of a physical environment. Advances in cognitive robotics transfer to artificial intelligence, which seeks to develop more efficient computer systems patterned on the versatility of human thought.

Professor Bram Van Heuveln, who organized the lab, said cognitive scientists have developed a suite of elements -- perception/action, planning, reasoning, memory, decision-making -- that are believed to constitute human thought. When properly modeled and connected, those elements are capable of solving complex problems without the raw power required by precise mathematical computations.

"Suppose we wanted to build a robot to catch fly balls in an outfield. There are two approaches: one uses a lot of calculations -- Newton's law, mechanics, trigonometry, calculus -- to get the robot to be in the right spot at the right time," said Van Heuveln."But that's not the way humans do it. We just keep moving toward the ball. It's a very simple solution that doesn't involve a lot of computation but it gets the job done."

Robotics are an ideal testing ground for that principle because robots act in the real world, and a correct cognitive solution will withstand the unexpected variables presented by the real world.

"The physical world can help us to drive science because it's different from any simulated world we could come up with -- the camera shakes, the motors slip, there's friction, the light changes," Veksler said."This platform -- robotics -- allows us to see that you can't rely on calculations. You have to be adaptive."

The lab is open to all students at Rensselaer. In its first semester, the lab has largely attracted computer science and cognitive science students enrolled in a Cognitive Robotics course taught by Veksler, but Veksler and Van Heuveln hope it will attract more engineering and art students as word of the facility spreads.

"We want different students together in one space -- a place where we can bring the different disciplines and perspectives together," said Van Heuveln."I would like students to use this space for independent research: they come up with the research project, they say 'let's look at this.'"

The lab is equipped with five"Create" robots -- essentially a Roomba robotic vacuum cleaner paired with a laptop; three hand-eye systems; one Chiara (which looks like a large metal crab); and 10 LEGO robots paired with the Sony Handy Board robotic controller.

On a recent day, Jacqui Brunelli and Benno Lee were working on their robot"cat" and"mouse" pair, which try to chase and evade each other respectively; Shane Reilly was improving the computer"vision" of his robotic arm; and Ben Ball was programming his robot to maintain a fixed distance from a pink object waved in front of its"eye."

"The thing that I've learned is that the sensor data isn't exact -- what it 'sees' constantly changes by a few pixels -- and to try to go by that isn't going to work," said Ball, a junior and student of computer science and physics.

Ball said he is trying to pattern his robot on a more human approach.

"We don't just look at an object and walk toward it. We check our position, adjusting our course," Ball said."I need to devise an iterative approach where the robot looks at something, then moves, then looks again to check its results."

The work of the students, who program their robots with the Tekkotsu open-source software, could be applied in future projects, said Van Heuveln.

"As a cognitive scientist, I want this to be built on elements that are cognitively plausible and that are recyclable -- parts of cognition that I can apply to other solutions as well," said Van Heuveln."To me, that's a heck of a lot more interesting than the computational solution."

In a generic domain, their early investigations clearly show how a more cognitive approach employing limited resources can easily outpace more powerful computers using a brute force approach, said Veksler.

"We look to humans not just because we want to simulate what we do, which is an interesting problem in itself, but also because we're smart," said Veksler."Some of the things we have, like limited working memory -- which may seem like a bad thing -- are actually optimal for solving problems in our environment. If you remembered everything, how would you know what's important?"

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New Psychology Theory Enables Computers to Mimic Human Creativity

Solving this"insight problem" requires creativity, a skill at which humans excel (the coin is a fake --"B.C." and Arabic numerals did not exist at the time) and computers do not. Now, a new explanation of how humans solve problems creatively -- including the mathematical formulations for facilitating the incorporation of the theory in artificial intelligence programs -- provides a roadmap to building systems that perform like humans at the task.

Ron Sun, Rensselaer Polytechnic Institute professor of cognitive science, said the new"Explicit-Implicit Interaction Theory," recently introduced in an article inPsychological Review, could be used for future artificial intelligence.

"As a psychological theory, this theory pushes forward the field of research on creative problem solving and offers an explanation of the human mind and how we solve problems creatively," Sun said."But this model can also be used as the basis for creating future artificial intelligence programs that are good at solving problems creatively."

The paper, titled"Incubation, Insight, and Creative Problem Solving: A Unified Theory and a Connectionist Model," by Sun and Sèbastien Hèlie of University of California, Santa Barbara, appeared in the July edition ofPsychological Review. Discussion of the theory is accompanied by mathematical specifications for the"CLARION" cognitive architecture -- a computer program developed by Sun's research group to act like a cognitive system -- as well as successful computer simulations of the theory.

In the paper, Sun and Hèlie compare the performance of the CLARION model using"Explicit-Implicit Interaction" theory with results from previous human trials -- including tests involving the coin question -- and found results to be nearly identical in several aspects of problem solving.

In the tests involving the coin question, human subjects were given a chance to respond after being interrupted either to discuss their thought process or to work on an unrelated task. In that experiment, 35.6 percent of participants answered correctly after discussing their thinking, while 45.8 percent of participants answered correctly after working on another task.

In 5,000 runs of the CLARION program set for similar interruptions, CLARION answered correctly 35.3 percent of the time in the first instance, and 45.3 percent of the time in the second instance.

"The simulation data matches the human data very well," said Sun.

Explicit-Implicit Interaction theory is the most recent advance on a well-regarded outline of creative problem solving known as"Stage Decomposition," developed by Graham Wallas in his seminal 1926 book"The Art of Thought." According to stage decomposition, humans go through four stages -- preparation, incubation, insight (illumination), and verification -- in solving problems creatively.

Building on Wallas' work, several disparate theories have since been advanced to explain the specific processes used by the human mind during the stages of incubation and insight. Competing theories propose that incubation -- a period away from deliberative work -- is a time of recovery from fatigue of deliberative work, an opportunity for the mind to work unconsciously on the problem, a time during which the mind discards false assumptions, or a time in which solutions to similar problems are retrieved from memory, among other ideas.

Each theory can be represented mathematically in artificial intelligence models. However, most models choose between theories rather than seeking to incorporate multiple theories and therefore they are fragmentary at best.

Sun and Hèlie's Explicit-Implicit Interaction (EII) theory integrates several of the competing theories into a larger equation.

"EII unifies a lot of fragmentary pre-existing theories," Sun said."These pre-existing theories only account for some aspects of creative problem solving, but not in a unified way. EII unifies those fragments and provides a more coherent, more complete theory."

The basic principles of EII propose the coexistence of two different types of knowledge and processing: explicit and implicit. Explicit knowledge is easier to access and verbalize, can be rendered symbolically, and requires more attention to process. Implicit knowledge is relatively inaccessible, harder to verbalize, and is more vague and requires less attention to process.

In solving a problem, explicit knowledge could be the knowledge used in reasoning, deliberately thinking through different options, while implicit knowledge is the intuition that gives rise to a solution suddenly. Both types of knowledge are involved simultaneously to solve a problem and reinforce each other in the process. By including this principle in each step, Sun was able to achieve a successful system.

"This tells us how creative problem solving may emerge from the interaction of explicit and implicit cognitive processes; why both types of processes are necessary for creative problem solving, as well as in many other psychological domains and functionalities," said Sun.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

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Breakthrough Chip Technology Lights Path to Exascale Computing: Optical Signals Connect Chips Together Faster and With Lower Power

The new technology, called CMOS Integrated Silicon Nanophotonics, is the result of a decade of development at IBM's global research laboratories. The patented technology will change and improve the way computer chips communicate -- by integrating optical devices and functions directly onto a silicon chip, enabling over 10X improvement in integration density than is feasible with current manufacturing techniques.

IBM anticipates that Silicon Nanophotonics will dramatically increase the speed and performance between chips, and further the company's ambitious exascale computing program, which is aimed at developing a supercomputer that can perform one million trillion calculations -- or an exaflop -- in a single second. An exascale supercomputer will be approximately one thousand times faster than the fastest machine today.

"The development of the Silicon Nanophotonics technology brings the vision of on-chip optical interconnections much closer to reality," said Dr. T.C. Chen, vice president, Science and Technology, IBM Research."With optical communications embedded into the processor chips, the prospect of building power-efficient computer systems with performance at the exaflop level is one step closer to reality."

In addition to combining electrical and optical devices on a single chip, the new IBM technology can be produced on the front-end of a standard CMOS manufacturing line and requires no new or special tooling. With this approach, silicon transistors can share the same silicon layer with silicon nanophotonics devices. To make this approach possible, IBM researchers have developed a suite of integrated ultra-compact active and passive silicon nanophotonics devices that are all scaled down to the diffraction limit -- the smallest size that dielectric optics can afford.

"Our CMOS Integrated Nanophotonics breakthrough promises unprecedented increases in silicon chip function and performance via ubiquitous low-power optical communications between racks, modules, chips or even within a single chip itself," said Dr. Yurii A. Vlasov, Manager of the Silicon Nanophotonics Department at IBM Research."The next step in this advancement is to establishing manufacturability of this process in a commercial foundry using IBM deeply scaled CMOS processes."

By adding just a few more processing modules to a standard CMOS fabrication flow, the technology enables a variety of silicon nanophotonics components, such as: modulators, germanium photodetectors and ultra-compact wavelength-division multiplexers to be integrated with high-performance analog and digital CMOS circuitry. As a result, single-chip optical communications transceivers can now be manufactured in a standard CMOS foundry, rather than assembled from multiple parts made with expensive compound semiconductor technology.

The density of optical and electrical integration demonstrated by IBM's new technology is unprecedented -- a single transceiver channel with all accompanying optical and electrical circuitry occupies only 0.5mm²-- 10 times smaller than previously announced by others. The technology is amenable for building single-chip transceivers with area as small as 4x4mm²that can receive and transmit over Terabits per second that is over a trillion bits per second.

The development of CMOS Integrated Silicon Nanophotonics is the culmination of a series of related advancements by IBM Research that resulted in the development of deeply scaled front-end integrated Nanophotonics components for optical communications. These milestones include:

• March 2010, IBM announced a Germanium Avalanche Photodetector working at unprecedented 40Gb/s with CMOS compatible voltages as low as 1.5V. This was the last piece of the puzzle that completes the prior development of the"nanophotonics toolbox" of devices necessary to build the on-chip interconnects.
• March 2008, IBM scientists announced the world's tiniest nanophotonic switch for"directing traffic" in on-chip optical communications, ensuring that optical messages can be efficiently routed.
• December 2007, IBM scientists announced the development of an ultra-compact silicon electro-optic modulator, which converts electrical signals into the light pulses, a prerequisite for enabling on-chip optical communications.
• December 2006, IBM scientists demonstrated silicon nanophotonic delay line that was used to buffer over a byte of information encoded in optical pulses -- a requirement for building optical buffers for on-chip optical communications.

The details and results of this research effort was reported in a presentation delivered by Dr. Yurii Vlasov at the major international semiconductor industry conference SEMICON held in Tokyo on Dec. 1, 2010. The talk is entitled"CMOS Integrated Silicon Nanophotonics: Enabling Technology for Exascale Computational Systems," co-authored by William Green, Solomon Assefa, Alexander Rylyakov, Clint Schow, Folkert Horst, and Yurii Vlasov of IBM's T.J. Watson Research Center in Yorktown Heights, N.Y. and IBM Zurich Research Lab in Rueschlikon, Switzerland.

Additional information on the project can be found athttp://www.research.ibm.com/photonics.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

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Genomic Fault Zones Come and Go: Fragile Regions in Mammalian Genomes Go Through 'Birth and Death' Process

"The genomic architecture of every species on Earth changes on the evolutionary time scale and humans are not an exception. What will be the next big change in the human genome remains unknown, but our approach could be useful in determining where in the human genome those changes may occur," said Pavel Pevzner, a UC San Diego computer science professor and an author on the new study. Pevzner studies genomes and genome evolution from a computational perspective in the Department of Computer Science and Engineering at the UC San Diego Jacobs School of Engineering.

The fragile regions of genomes are prone to"genomic earthquakes" that can trigger chromosome rearrangements, disrupt genes, alter gene regulation and otherwise play an important role in genome evolution and the emergence of new species. For example, humans have 23 chromosomes while some other apes have 24 chromosomes, a consequence of a genome rearrangement that fused two chromosomes in our ape ancestor into human chromosome 2.

This work was performed by Pevzner and Max Alekseyev -- a computer scientist who recently finished his Ph.D. in the Department of Computer Science and Engineering at the UC San Diego Jacobs School of Engineering. Alekseyev is now a computer science professor at the University of South Carolina.

Turnover Fragile Breakage Model

"The main conclusion of the new paper is that these fragile regions are moving," said Pevzner.

In 2003, Pevzner and UC San Diego mathematics professor Glen Tesler published results claiming that genomes have"fault zones" or genomic regions that are more prone to rearrangements than other regions. Their"Fragile Breakage Model" countered the then largely accepted"Random Breakage Model" -- which implies that there are no rearrangement hotspots in mammalian genomes. While the Fragile Breakage Model has been supported by many studies in the last seven years, the precise locations of fragile regions in the human genome remain elusive.

The new work published inGenome Biologyoffers an update to the Fragile Breakage Model called the"Turnover Fragile Breakage Model." The findings demonstrate that the fragile regions undergo a birth and death process over evolutionary timescales and provide a clue to where the fragile regions in the human genome are located.

Do the Math: Find Fragile Regions

Finding the fragile regions within genomes is akin to looking at a mixed up deck of cards and trying to determine how many times it has been shuffled.

Looking at a genome, you may identify breaks, but to say it is a fragile region, you have to know that breaks occurred more than once at the same genomic position."We are figuring out which regions underwent multiple genome earthquakes by analyzing the present-day genomes that survived these earthquakes that happened millions of years ago. The notion of rearrangements cannot be applied to a single genome at a single point in time. It's relevant when looking at more than one genome," said Pevzner, explaining the comparative genomics approach they took.

"It was noticed that while fragile regions may be shared across different genomes, most often such shared fragile regions are found in evolutionarily close genomes. This observation led us to a conclusion that fragility of any particular genomic position may appear only for a limited amount of time. The newly proposed Turnover Fragile Breakage Model postulates that fragile regions are subject to a 'birth and death' process and thus have limited lifespan," explained Alekseyev.

The Turnover Fragile Breakage Model suggests that genome rearrangements are more likely to occur at the sites where rearrangements have recently occurred -- and that these rearrangement sites change over tens of millions of years. Thus, the best clue to the current locations of fragile regions in the human genome is offered by rearrangements that happened in our closest ancestors -- chimpanzee and other primates.

Pevzner is eagerly awaiting sequenced primate genomes from the Genome 10K Project. Sequencing the genomes of 10,000 vertebrate species -- including 100s of primates -- is bound to provide new insights on human evolutionary history and possibly even the future rearrangements in the human genome.

"The most likely future rearrangements in human genome will happen at the sites that were recently disrupted in primates," said Pevzner.

Work tied to the new Turnover Fragile Breakage Model may also be useful for understanding genome rearrangements at the level of individuals, rather than entire species. In the future, the computer scientists hope to use similar tools to look at the chromosomal rearrangements that occur within the cells of individual cancer patients over and over again in order to develop new cancer diagnostics and drugs.

Pavel Pevzner is the Ronald R. Taylor Professor of Computer Science at UC San Diego; Director of the NIH Center for Computational Mass Spectrometry; and a Howard Hughes Medical Institute (HHMI) Professor.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

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'Racetrack' Magnetic Memory Could Make Computer Memory 100,000 Times Faster

Annoyed by how long it took his computer to boot up, Kläui began to think about an alternative. Hard disks are cheap and can store enormous quantities of data, but they are slow; every time a computer boots up, 2-3 minutes are lost while information is transferred from the hard disk into RAM (random access memory). The global cost in terms of lost productivity and energy consumption runs into the hundreds of millions of dollars a day.

Like the tried and true VHS videocassette, the proposed solution involves data recorded on magnetic tape. But the similarity ends there; in this system the tape would be a nickel-iron nanowire, a million times smaller than the classic tape. And unlike a magnetic videotape, in this system nothing moves mechanically. The bits of information stored in the wire are simply pushed around inside the tape using a spin polarized current, attaining the breakneck speed of several hundred meters per second in the process. It's like reading an entire VHS cassette in less than a second.

In order for the idea to be feasible, each bit of information must be clearly separated from the next so that the data can be read reliably. This is achieved by using domain walls with magnetic vortices to delineate two adjacent bits. To estimate the maximum velocity at which the bits can be moved, Kläui and his colleagues* carried out measurements on vortices and found that the physical mechanism could allow for possible higher access speeds than expected.

Their results were published online October 25, 2010, in the journalPhysical Review Letters. Scientists at the Zurich Research Center of IBM (which is developing a racetrack memory) have confirmed the importance of the results in a Viewpoint article. Millions or even billions of nanowires would be embedded in a chip, providing enormous capacity on a shock-proof platform. A market-ready device could be available in as little as 5-7 years.

Racetrack memory promises to be a real breakthrough in data storage and retrieval. Racetrack-equipped computers would boot up instantly, and their information could be accessed 100,000 times more rapidly than with a traditional hard disk. They would also save energy. RAM needs to be powered every millionth of a second, so an idle computer consumes up to 300 mW just maintaining data in RAM. Because Racetrack memory doesn't have this constraint, energy consumption could be slashed by nearly a factor of 300, to a few mW while the memory is idle. It's an important consideration: computing and electronics currently consumes 6% of worldwide electricity, and is forecast to increase to 15% by 2025.

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Supercomputing Center Breaks the Petaflops Barrier

NERSC's newest supercomputer, a 153,408 processor-core Cray XE6 system, posted a performance of 1.05 petaflops (quadrillions of calculations per second) running the Linpack benchmark. In keeping with NERSC's tradition of naming computers for renowned scientists, the system is named Hopper in honor of Admiral Grace Hopper, a pioneer in software development and programming languages.

NERSC serves one of the largest research communities of all supercomputing centers in the United States. The center's supercomputers are used to tackle a wide range of scientific challenges, including global climate change, combustion, clean energy, new materials, astrophysics, genomics, particle physics and chemistry. The more than 400 projects being addressed by NERSC users represent the research mission areas of DOE's Office of Science.

The increasing power of supercomputers helps scientists study problems in greater detail and with greater accuracy, such as increasing the resolution of climate models and creating models of new materials with thousands of atoms. Supercomputers are increasingly used to compliment scientific experimentation by allowing researchers to test theories using computational models and analyzed large scientific data sets. NERSC is also home to Franklin, a 38,128 core Cray XT4 supercomputer with a Linpack performance of 266 teraflops (trillions of calculations per second). Franklin is ranked number 27 on the newest TOP500 list.

The system, installed d in September 2010, is funded by DOE's Office of Advanced Scientific Computing Research.

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'Space-Time Cloak' to Conceal Events

Previously, a team led by Professor Sir John Pendry at Imperial College London showed that metamaterials could be used to make an optical invisibility cloak. Now, a team led by Professor Martin McCall has mathematically extended the idea of a cloak that conceals objects to one that conceals events.

"Light normally slows down as it enters a material, but it is theoretically possible to manipulate the light rays so that some parts speed up and others slow down," says McCall, from the Department of Physics at Imperial College London. When light is 'opened up' in this way, rather than being curved in space, the leading half of the light speeds up and arrives before an event, whilst the trailing half is made to lag behind and arrives too late. The result is that for a brief period the event is not illuminated, and escapes detection. Once the concealed passage has been used, the cloak can then be 'closed' seamlessly.

Such a space-time cloak would open up a temporary corridor through which energy, information and matter could be manipulated or transported undetected."If you had someone moving along the corridor, it would appear to a distant observer as if they had relocated instantaneously, creating the illusion of a Star-Trek transporter," says McCall."So, theoretically, this person might be able to do something and you wouldn't notice!"

While using the spacetime cloak to make people move undetected is still science fiction, there are many serious applications for the new research, which was funded by the Engineering and Physical Sciences Research Council (EPSRC) and the Leverhulme Trust. Co-author Dr Paul Kinsler developed a proof of concept design using customised optical fibres, which would enable researchers to use the event cloak in signal processing and computing. A given data channel could for example be interrupted to perform a priority calculation on a parallel channel during the cloak operation. Afterwards, it would appear to external parts of the circuit as though the original channel had processed information continuously, so as to achieve 'interrupt-without-interrupt'.

Alberto Favaro, who also worked on the project, explains:"Imagine computer data moving down a channel to be like a highway full of cars. You want to have a pedestrian crossing without interrupting the traffic, so you slow down the cars that haven't reached the crossing, while the cars that are at or beyond the crossing get sped up, which creates a gap in the middle for the pedestrian to cross. Meanwhile an observer down the road would only see a steady stream of traffic." One issue that cropped up during their calculations was to speed up the transmitted data without violating the laws of relativity. Favaro solved this by devising a clever material whose properties varied in both space and time, allowing the cloak to be formed.

"We're sure that there are many other possibilities opened up by our introduction of the concept of the spacetime cloak,' says McCall,"but as it's still theoretical at this stage we still need to work out the concrete details for our proposed applications."

Metamaterials is an expanding field of science, with a vast array of potential uses, spanning defence, security, medicine, data transfer and computing. Many ordinary household devices that work using electromagnetic fields could be made more cheaply or to work at higher speeds. Metamaterials could also be used to control other types of waves as well as light, such as sound or water waves, opening up potential applications for protecting coastal or offshore installations, or even engineering buildings to withstand earthquake waves.

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