VOA慢速英語:超級電腦更快，更給力
Hello there, and welcome to As It Is. I’m Faith Lapidusin Washington.
Computer technology has revolutionized the world. It has changed the way people interact and how quicklythey are able to connect with each other. Today wehear how super computers are getting smarter andfaster.
We begin with a look the most powerful supercomputer in the world. China’s Tianhe-2 supercomputer has again been rated the world's mostpowerful computer. It is the second time in 12 monthsthat the Tianhe-2 has taken the number one spot on the Top500’s list of the most powerful super computers. Caty Weaver reports.
Super Computers Faster, More Powerful
Experts measured the super computer’s performance at 33.86 petaflops, orquadrillions of operations per second. China's National University of DefenseTechnology developed the super computer, which runs twice as fast as thenumber two-rated Titan super computer. It belongs to the United Statesgovernment’s Oakridge National Laboratory in Tennessee. Both Tianhe-2 andTitan are part of an ongoing race to make super computers faster and morepowerful.
So what is a super computer?
A basic personal computer has one microchip at the center of its operations. This Central Processing Unit, or CPU, executes a set of commandscontained in a predesigned program.
The first super computers had a few more CPUs. That number grew asmicroprocessors became cheaper and faster. Andrew Grimshaw, acomputer science professor at the University of Virginia, explains.
"Today, super computers are all what we call parallel machines. Instead ofone CPU - central processing unit - they have thousands and thousands. And in the case of the Chinese machine, depending on how you count, millions ofthese central processing units."
These parallel machines are made up of many individual computers callednodes. They are all positioned in one block. They use a lot of power, create alot of heat and require huge cooling systems. They also use programsdifferent from those used by ordinary computers.
Professor Grimshaw says anyone with enough resources can build a supercomputer to solve problems that require millions of mathematicalcalculations.
But that is not always necessary. A virtual super computer can be created bynetworking individual computers within a university campus or company. These machines then process data during down time, when no one is usingthem.
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a Corvette and truck flooded by the storm surgeof Superstorm Sandy stand in a driveway inLindenhurst, New York. (Reuters) |
"Those are very easy to run on virtual super computers because eachproblem is independent of all the others and I can scatter these jobs outaround the place. We run these all the time at UVA."
Professor Grimshaw says that until ten years ago, engineers worked onmaking computers faster. Since then, he says, they have worked to createmore powerful parallel machines.
"It’s transforming science and engineering, and it’s going to continue totransform it in ways that I think most people don’t fully grasp how well we canmodel and simulate the world now."
Professor Grimshaw says the increasing computing ability of supercomputers makes the future of research very bright.
I'm Caty Weaver.
And I’m Faith Lapidus. You are listening to As It Is from VOA LearningEnglish.
Severe weather events affect communities in all parts of the world. Earthquakes, typhoons, tsunamis, and tornados have caused billions ofdollars in damage and killed hundreds of thousands of people. WhenHurricane Sandy struck the United States in 2012, many people complainedthat weather reports leading up to the storm had not been correct. Now,scientists are looking to super computers to help improve weatherpredictions. June Simms has more.
NOAA Hopes They Will Improve Weather Predictions
Predicting the strength and movement of these huge storm systems is ofcrucial importance. Thanks to new super computers, meteorologists for theNational Oceanic and Atmospheric Administration (NOAA) are getting better atpredicting the weather as far as six days out.
Hurricane Sandy was one of the costliest storms inUnited States history. At the time, some people blamedmeteorologists for not correctly predicting the path of the storm.
But weather forecasting is extremely difficult, says BenKyger. He is the director of central operations atNOAA’s National Centers for Environmental Predictionin College Park, Maryland.
“You’ve got major patterns in the atmosphere, like the jet stream, but you’ve also got little eddies, little currents, little things happening all over the place. All these little changes are interacting with each other, continuously, all day long. So if you look at it from above, from a satellite, you see the atmosphere moving and churning in big ways and little ways.”
Ben Kyger says oceans are another issue because they closely interact with the atmosphere and have a huge effect on storms.
NOAA has spent about $20 million on two new super computers in an effort to improve the dependability of its forecasts.
“These computers generate the initial model guidance that the whole forecast process depends on, for all the weather information that you see, with snowstorms, tornadoes, hurricanes, how hot it’s going to be today -- all of your weather forecasts start with what comes off of these super computers.”
It takes a huge amount of computational power to examine data from weather satellites, ground stations and other sources. It then takes a lot of power to predict temperature, air pressure, humidity and wind speed.
But human brains and experience are still very important to the process.
Meteorologists at the National Centers for Environmental Prediction scan the same data that the super computers get before issuing a weather report.
“They’re looking at lots of different models, that run off different computers and then they’re creating that five-day forecast. They use lots of scientific and subjective knowledge from doing it year after year. They know where the models are strong. They know where they’re weak, and they give us significantly better forecasts than the models would all by themselves.”
NOAA issues worldwide forecasts every six hours, every day of the year. The reports are free and are helpful for many countries that cannot afford their own weather service. NOAA continues working to improve its weather forecasting abilities. Another upgrade of its weather-predicting super computers is planned for as early as 2015.
I’m June Simms.
That’s our show for today. I’m Faith Lapidus. VOA world news is coming up at the top of the hour, Universal Time.
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