(Press-News.org) HOUSTON -- (June 7, 2012) -- Researchers from Rice University and UCLA unveiled a new data-encoding scheme this week that slashes more than 30 percent of the energy needed to write data onto new memory cards that use "phase-change memory" (PCM) -- a competitor to flash memory that has big backing from industry heavyweights.
The breakthrough was presented at the IEEE/ACM Design Automation Conference (DAC) in San Francisco by researchers from Rice University's Adaptive Computing and Embedded Systems (ACES) Laboratory.
PCM uses the same type of materials as those used in rewritable CDs and DVDs, and it does the same job as flash memory -- the mainstay technology in USB thumb drives and memory cards for cameras and other devices. IBM and Samsung have each demonstrated PCM breakthroughs in recent months, and PCM is ultimately expected to be faster, cheaper and more energy-efficient than flash.
"We developed an optimization framework that exploits asymmetries in PCM read/write to minimize the number of bit transitions, which in turns yields energy and endurance efficiency," said researcher Azalia Mirhoseini, a Rice graduate student in electrical and computer engineering, who presented the research results at DAC.
In PCM technology, heat-sensitive materials are used to store data as ones and zeros by changing the material resistance. The electronic properties of the material change from low resistance to high resistance when heat is applied to alter the arrangement of atoms from a conducting, crystalline structure to a nonconducting, glassy structure. Writing data on PCM takes a fraction of the time required to write on flash memory, and the process is reversible but asymmetric; creating one state requires a short burst of intense heat, and reversing that state requires more time and less heat.
The new encoding method is the first to take advantage of these asymmetric physical properties. One key to the encoding scheme is reading the existing data before new data is written. Using a combination of programming approaches, the researchers created an encoder that can scan the "words" -- short sections of bits on the card -- and overwrite only the parts of the words that need to be overwritten.
"One part of the method is based on dynamic programming, which starts from small codes that we show to be optimal, and then builds upon these small codes to rapidly search for improved, longer codes that minimize the bit transitions," said lead researcher Farinaz Koushanfar, director of Rice's ACES Laboratory and assistant professor of electrical and computer engineering and of computer science at Rice.
The second part of the new method is based on integer-linear programming (ILP), a technique that can find optimal solutions. The more complex the solution, the longer ILP takes to find the optimal solution, so the team found a shortcut by using dynamic programming to create a cheat sheet of small codes that could be quickly combined for more complex solutions.
Research collaborator Miodrag Potkonjak, professor of computer science at UCLA, said the team's solution to PCM optimization is pragmatic.
"The overhead for ILP is practical because the codes are found only once, during the design phase," Potkonjak said. "The codes are stored for later use during PCM operation."
The researchers also found the new encoding scheme cut more than 40 percent of "memory wear," the exhaustion of memory due to rewrites. Each memory cell can handle a limited number of rewrite cycles before it becomes unusable.
The researchers said the applicability, low overhead and efficiency of the proposed optimization methods were demonstrated with extensive evaluations on benchmark data sets. In addition to PCM, they said, the encoding method is also applicable for other types of bit-accessible memories, including STT-RAM, or spin-transfer torque random-access memory.
###
The research was funded by the Office of Naval Research, the Army Research Office and the National Science Foundation.
A copy of the DAC paper is available at:
http://dl.acm.org/citation.cfm?id=2228374
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is known for its "unconventional wisdom." With 3,708 undergraduates and 2,374 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 4 for "best value" among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to www.rice.edu/nationalmedia/Rice.pdf.
END
HOUSTON -- (June 7, 2012) -- Thanks to a little serendipity, researchers at Rice University have created a tiny coaxial cable that is about a thousand times smaller than a human hair and has higher capacitance than previously reported microcapacitors.
The nanocable, which is described this week in Nature Communications, was produced with techniques pioneered in the nascent graphene research field and could be used to build next-generation energy-storage systems. It could also find use in wiring up components of lab-on-a-chip processors, but its discovery is owed partly ...
Alex Membrillo, the co-founder of Cardinal Web Solutions, an Atlanta Internet Marketing firm, was recently featured in an article for Entrepreneur.com. Written by Lambeth Hochwald, the piece, "5 Ways to Make Sweet Music for Your Business," was published on May 29, 2012. It discusses how music can be used to positively influence sales and motivate staff.
In the article Mr. Membrillo explains how Cardinal Web Solutions (CWS) uses music to energize employees, encourage innovative ideas, and recognize achievements. "In the ever changing world of Internet ...
SAN FRANCISCO – June 7, 2012 – A simple eye test may someday offer an effective way to identify patients who are at high risk for stroke, say researchers at the University of Zurich. They showed that a test called ocular pulse amplitude (OPA) can reliably detect carotid artery stenosis (CAS), a condition that clogs or blocks the arteries that feed the front part of the brain. It's a known risk factor for stroke. The OPA test could be performed by ophthalmologists – physicians who treat eye diseases – during routine exams. The study, which is published in the June issue ...
NEWPORT, Ore. – When debris from the 2011 earthquake and tsunami in Japan began making its way toward the West Coast of the United States, there were fears of possible radiation and chemical contamination as well as costly cleanup.
But a floating dock that unexpectedly washed ashore in Newport this week and has been traced back to the Japanese disaster has brought with it a completely different threat – invasive species.
Scientists at Oregon State University's Hatfield Marine Science Center said the cement float contains about 13 pounds of organisms per square foot, ...
Do rebelliousness, emotional control, toughness and thrill-seeking still make up the essence of coolness?
Can performers James Dean and Miles Davis still be considered the models of cool?
Research led by a University of Rochester Medical Center psychologist and published by the Journal of Individual Differences has found the characteristics associated with coolness today are markedly different than those that generated the concept of cool.
"When I set out to find what people mean by coolness, I wanted to find corroboration of what I thought coolness was," said Ilan ...
7 June 2012: Element Six, the world leader in synthetic diamond supermaterials, working in partnership with academics in Harvard University, California Institute of Technology and Max-Planck-Institut für Quantenoptik, has used its Element Six single crystal synthetic diamond grown by chemical vapour deposition (CVD) to demonstrate the capability of quantum bit memory to exceed one second at room temperature.
This study demonstrated the ability of synthetic diamond to provide the read-out of a quantum bit which had preserved its spin polarisation for several minutes and ...
Find Me Gluten Free, the most downloaded gluten-free restaurant and business finder app for iPhone and Android announces partnership with Brandy Wendler, Mrs. Alaska International 2012 to create awareness for the Celiac Disease and Gluten Free Community.
Find Me Gluten Free rates businesses on how gluten-free friendly they are, making it easier to find a restaurant which users can be confident will take preparing a gluten-free meal seriously, along with serving as a brand-finder at stores nationwide.
Brandy Wendler was diagnosed with Celiac Disease in 2008. It was ...
The NationaLease Spring Maintenance Managers Meeting in Greenville, SC, in May provided attendees with a stimulating mix of technology, product, and professional education, as well as a strong measure of motivation and inspiration provided by its keynote speaker, Jay Blake, racing's only blind race crew chief.
The four-day event also included a ceremony announcing NationaLease's Exceptional Service Award winners, which are NationaLease member companies that provided particularly outstanding reciprocal road service to fellow members throughout the year. "This year's ...
University of Notre Dame network physicists Mária Ercsey-Ravasz and Zoltán Toroczkai of the Interdisciplinary Center for Network Science and Applications, in collaboration with food science experts, have recently published a rigorous analysis of the international food-trade network that shows the network's vulnerability to the fast spread of contaminants as well as the correlation between known food poisoning outbreaks and the centrality of countries on the network.
Together with food science experts József Baranyi, from the Institute of Food Research in the U.K., and ...
RICHMOND, Va. (June 7, 2012) – A new study from the Virginia Commonwealth University School of Medicine has identified molecular changes responsible for abnormal cholesterol production and metabolism in the livers of patients with a common liver condition, and these changes may explain the severity of a patient's liver disease and risks to their heart health.
It is estimated that a third of Americans have a fatty liver. Nonalcoholic fatty liver disease is a very common liver condition. Nonalcoholic steatohepatitis, or NASH, the more aggressive form of nonalcoholic fatty ...
