Monday, September 29, 2008

Teaching Robots New Tricks

Robotic helicopters learn complex tricks by analyzing demos.

By Rachel Kremen

Programming instructions for robots can be a time-consuming, labor-intensive task. Many roboticists believe that training robots by demonstrating new skills could speed up the process and enable the machines to perform more difficult tasks. Now researchers have created such a system for robotic helicopters. With their approach, the team can train a robotic helicopter to perform a complicated aerial maneuver in less than 30 minutes simply by analyzing video footage of the trick. The work could one day be applied to a wide variety of robots on land and sea, as well as in the air.

For very basic aerial maneuvers, researchers can program specific commands based on the way a human operator would use the controls. But aerial acrobatics, such as flying upside down, require a more robust and adaptive approach. A gust of wind or a small variation in the helicopter's starting position can send the vehicle completely off course if adjustments aren't made immediately to the flight plan. "It's not sufficient to just replay the same sequence of controls as a human pilot," says Pieter Abbeel, who worked as a researcher on the project while completing his PhD at Stanford University. With the apprenticeship approach, the robot can make changes mid-flight because it's not tied to a specific series of commands. This could help autonomous helicopters deal with real-world challenges, such as landing on slanted terrain or coping with sudden changes in weather conditions, ultimately resulting in more stable flight.

Training begins with a human expert demonstrating a new trick on a remote-controlled helicopter. As the expert repeats the maneuver, one of the researchers presses a button to indicate the start and end time of each attempt. The expert needs to perform each trick approximately 10 times, so that subtle deviations can be eliminated and the software can calculate the ideal path. The software carefully warps the timing of each video clip so that it can compare the attempts. Small blips in the data, known as noise, are also eliminated. Ultimately, the software creates a highly accurate aerodynamic model of the trick that the autonomous helicopter uses as a flight guide.

Once in the air, the robotic helicopter wirelessly relays information from its onboard sensors to a computer on the ground. "We place a number of instruments on the helicopters--gyroscopes, accelerometers, and a magnetic compass--to figure out the position and orientation," saysAndrew Ng, an assistant professor of computer science at Stanford University, who also worked on the project. "We wirelessly send the instrument readings down to a desktop computer on the ground, which computes the appropriate control commands." These commands are sent back to the helicopter 20 times per second. Video cameras on the ground also help to keep track of the helicopter.

With each attempt, the robot learns how to perfect the trick. "The first time, it might take a turn a bit too wide. It will then use its knowledge of its own dynamics to learn to adjust the way it takes a turn," Ng says.

Watch and learn: Researchers at Stanford University taught autonomous helicopters, such as the one shown above, how to perform tricks using an approach called ‘apprenticeship learning’. An ideal flight path was created for each trick using software that automatically analyzed video clips of the maneuver. Credit: Ben Tse

MULTIMEDIA   Watch an autonomous helicopter perform several complicated stunts.

At a recent demonstration at Stanford, an autonomous helicopter used this approach to perform several complicated tricks, including loops with pirouettes and a backward funnel maneuver known as the hurricane. The team was even able to demonstrate a particularly difficult stunt called the tic toc, in which the helicopter hovers with its tail down while its nose swings back and forth like an inverted pendulum. Such a trick had been impossible to perform using hard coding, and it represented an impressive achievement for the team. "We can now trust our helicopter controls a lot more [and achieve] higher-performance flight," says Abbeel, who now works as an assistant professor in the Department of Electrical Engineering and Computer Science at the University of California, Berkeley.

Eric Feron, a professor of aerospace engineering at the Georgia Institute of Technology, was not involved in the Stanford project but is impressed by the performance of the autonomous helicopters trained using the approach. He also appreciates the underlying methodology. "When I was involved in similar research back in early 2000," he says, "there was definitely what I would call human intervention in figuring out what the online control systems should be doing in order to repeat the maneuvers. We had to program the computers ourselves." Feron says the Stanford work represents a significant gain in efficiency, by cutting down the learning time to half an hour. "At the end of our research, we were able to maybe do a new maneuver in one day," he says.

Abbeel notes that while the autonomous helicopters have achieved a new level of reliability, there is room for improvement, and safety will be a key concern if such robots are ever flown over populated areas. The machines have to be able to fly at least as well as an expert human pilot, even while doing complicated maneuvers, he says, and simple back-and-forth flight won't be good enough for search-and-rescue missions. "I like to imagine a future in which someday, if there is an accident out on the ocean, a fleet of a dozen autonomous helicopters can be instantaneously deployed to search for survivors," he says. This could help offset the lack of human pilots qualified to perform such a task and increase the chance of locating survivors.

The learning system could be used on other kinds of robots as well, Ng says, such as those that do housework or work in factories. "It could also allow for the very precise control of cars, motorcycles, fixed-wing aircraft, and even sea-based vehicles," he says.

In the future, the team hopes to make their system more flexible. "When we as humans learn, there are many things that speed up the process besides demonstrations. An expert pilot might give advice in other forms," says Abbeel, such as verbal or written tips. Ideally, the team hopes to design a system that can incorporate such advice.

Oiling the system

Sep 28th 2008
From Economist.com

It may seem unfair, but a bailout is essential

SUSPICION of banks is a recurrent historical theme, from President Andrew Jackson’s opposition to “money power” in the early 19th century, to the British Labour party’s suspicion of the “bankers’ ramp” that forced it from office in 1931.

So there is a natural temptation to think that the current crisis may be entirely artificial, a device dreamed up by bankers to help them out of a hole. But if there is a conspiracy, it is extremely well organised and extraordinarily risky.

The money markets are a bit like the sewers of the financial system: in normal times, nobody notices them but when they get blocked up, the stench is abominable. And they are severely congested at the moment. The good news is that, unlike last week, it is possible for banks to borrow overnight at a reasonable rate. The bad news is that borrowing at longer rates is either impossible or prohibitively expensive.

Why is this? The problem seems to relate to the money-market fund sector, which suffered an outflow of assets when one of them “broke the buck” (failed to repay clients at face value) last week. Other funds are desperate not to repeat the trick, so are desperately opting for safe assets, which means those offered by the American government.

Consequently, three-month Treasury bills were yielding just 0.43% last week (something like 2% would be more normal). According to Barclays Capital, the cost of long-term financial debt was some 450 basis points (4.5 percentage points) above that of government debt, compared with a normal spread of less than 50 basis points. Shorter term, the gap between three month Libor (the rate at which banks borrow) and that paid by the government is getting wider and wider (see chart).

At that level, it is simply uneconomic for banks to lend money to customers. So they won’t. Banks are getting by on borrowing overnight, but the markets for one and three-month loans have dried up. That explains why central banks have been forced to offer billions of dollars at those maturities.

This cannot last long without causing immense damage. Companies will be unable to raise new money and, more importantly, refinance old loans. Corporate bankruptcies will soar. Consumers will also find it difficult, or expensive, to borrow. The result will be a sharp downturn in demand that will push the economy into a deep recession.

So some kind of bailout deal is necessary. Whether all the details were right is, at the moment, secondary to whether it does the trick. And the trick will be the restoration of confidence in the banking system.

It is, indeed, unfair that banks tend to be rescued when they go wrong whereas coal mines and shoe retailers do not. But banks play a key role in oiling the system; they provide the credit that lets the rest of us do business. They also have innate risk, because they lend more money then they have cash in hand. To put it another way, they borrow short and lend long. This has made them the subject of panics throughout history, and those panics have always led to economic turbulence. The authorities can let them go bust, but the risk is depression. Or they can hold their noses and bail them out.

They have, after all, not got away entirely scot-free. A lot of bonuses in recent years have been paid in the form of restricted stock, and that has fallen sharply in value. Jobs have been lost at Bear Stearns and Lehman Brothers, and more will follow. In future, banks will have to accept a lot more regulation; in particular, higher capital ratios that will restrict the potential for profitability.

And there will be more crises in future. Now that investment banks are part of commercial banks, we have returned to the risks that characterised the system before the Glass-Steagall Act of 1933—specifically, that reckless investment banks can fritter away retail depositors’ money. And what will we have to do if that happens? Bail them out again.

Thursday, October 02, 2008 Hijacking Satellite Navigation Sending false signals to GPS receivers could disrupt critical infrastructure. By Erica Naone The Global Positioning System (GPS) lies at the heart of an increasing number of technologies, from vehicle navigation systems to the power grid. And yet, although the military version of GPS includes security features such as encryption, civilian signals are transmitted in the clear. Now, researchers at Cornell University and Virginia Tech have demonstrated a relatively simple way to fool ordinary GPS receivers into accepting bogus signals using a briefcase-size transmitter. Paul Kintner, a professor of electrical and computer engineering at Cornell, who worked on the project, warns that society is becoming dependent on GPS for an ever-broadening list of applications, including management of the power grid and tracking criminals under house arrest. "I'm just amazed at the way people are using these GPS systems," Kintner says. "Ten years from now, there will be more ways that we just don't know about--it migrates into our technological fabric, and we become dependent on it." Kintner and his group, which recently presented details of the spoofing attack at the Institute of Navigation's Global Navigation Satellite Systems (GNSS) meeting in Savannah, GA, did not start out looking for a way to subvert GPS. They were working on a software-based GPS receiver to help them understand the effects of solar flares on GPS satellites. But as their design progressed, Todd Humphreys, one of the researchers in the group, realized that the same system could be used to spoof ordinary GPS signals. Here's how GPS works: roughly 30 satellites orbit the earth, broadcasting signals that can be picked up by a receiver virtually anywhere on the planet. By collecting signals from several satellites and measuring the time delay between each signal, GPS receivers can calculate their exact position and receive very precise time signals. The software GPS device built at Cornell can receive and transmit any GPS signal. To attack a target receiver, the device need only be placed nearby. It would start out simply retransmitting ordinary satellite signals without any modifications. After a few seconds, the target receiver should focus on the signal coming from the device, because it's the clearest source. At that point, the device could begin modifying transmissions, altering the signals little by little until the target receiver shows any time and position the attacker chooses. Kintner says that an attacker could use fake GPS signals to disrupt the power grid, potentially causing power spikes and even damaging generators. The same trick could let criminals under house arrest move around freely, he adds. Out of position: Researchers have found that a software-based GPS device (shown above) can fool GPS receivers into accepting erroneous positional information. The attack could disrupt critical infrastructure, they warn.  Credit: Paul Kintner and Steve Powell, School of Electrical and Computer Engineering, Cornell Univers The Global Positioning System (GPS) lies at the heart of an increasing number of technologies, from vehicle navigation systems to the power grid. And yet, although the military version of GPS includes security features such as encryption, civilian signals are transmitted in the clear. Now, researchers at Cornell University and Virginia Tech have demonstrated a relatively simple way to fool ordinary GPS receivers into accepting bogus signals using a briefcase-size transmitter. Paul Kintner, a professor of electrical and computer engineering at Cornell, who worked on the project, warns that society is becoming dependent on GPS for an ever-broadening list of applications, including management of the power grid and tracking criminals under house arrest. "I'm just amazed at the way people are using these GPS systems," Kintner says. "Ten years from now, there will be more ways that we just don't know about--it migrates into our technological fabric, and we become dependent on it." Kintner and his group, which recently presented details of the spoofing attack at the Institute of Navigation's Global Navigation Satellite Systems (GNSS) meeting in Savannah, GA, did not start out looking for a way to subvert GPS. They were working on a software-based GPS receiver to help them understand the effects of solar flares on GPS satellites. But as their design progressed, Todd Humphreys, one of the researchers in the group, realized that the same system could be used to spoof ordinary GPS signals. Here's how GPS works: roughly 30 satellites orbit the earth, broadcasting signals that can be picked up by a receiver virtually anywhere on the planet. By collecting signals from several satellites and measuring the time delay between each signal, GPS receivers can calculate their exact position and receive very precise time signals. The software GPS device built at Cornell can receive and transmit any GPS signal. To attack a target receiver, the device need only be placed nearby. It would start out simply retransmitting ordinary satellite signals without any modifications. After a few seconds, the target receiver should focus on the signal coming from the device, because it's the clearest source. At that point, the device could begin modifying transmissions, altering the signals little by little until the target receiver shows any time and position the attacker chooses. Kintner says that an attacker could use fake GPS signals to disrupt the power grid, potentially causing power spikes and even damaging generators. The same trick could let criminals under house arrest move around freely, he adds.

Outsourcing

Sep 29th 2008
From Economist.com

Outsourcing is a term used to describe almost any corporate activity that is managed by an outside vendor, from the running of the company’s cafeteria to the provision of courier services. It is most commonly used, however, to apply to the transfer of the management of an organisation’s computer facilities to an outside agent. This transfer of management responsibility is frequently accompanied by a transfer (from the buyer of the outsourcing service to the vendor) of the specialist internal staff who are already carrying out that activity.

Outsourcing has three main advantages:

• The greater economies of scale that can be gained by a third party that is able to pool the activity of a large number of firms. It is thus frequently cheaper for a firm to outsource specialist activities (where it cannot hope to gain economies of scale on its own) than it is to carry them out itself. Some firms gain the economies of scale by taking on the activity of others, becoming an outsourcer themselves.

• The ability of a specialist outsourcing firm to keep abreast of the latest developments in its field. This has been a particularly significant factor in the area of information technology, where technological change has been so rapid that companies’ in-house capabilities are hard pressed to keep up with it.

• The way that it enables small firms to do things for which they could not justify hiring full-time employees.

The most commonly cited disadvantage of outsourcing is the loss of control involved in derogating responsibility for particular processes to others.

Outsourcing is not a new phenomenon. Companies have outsourced their advertising, for instance, for almost as long as advertising has been in existence (and J. Walter Thompson has been in business since the 1880s). Financial services such as factoring and leasing, the outsourcing respectively of the accounts receivable function and of capital funding, have also been available from outside providers for many years.

But it has grown exceptionally fast in recent years. According to one estimate, in 1946 only 20% of a typical American manufacturing company’s value-added in production and operations came from outside sources; 50 years later the proportion had tripled to 60%.

Much of the increase came from the outsourcing of IT functions. This was bolstered later by the outsourcing of other functions (such as logistics) that were in areas that themselves had a high degree of it content. Banks, for instance, began to outsource the IT-intensive processing of financial instruments such as loans or mortgage-backed securities. The savings from such moves could be dramatic. By deciding to outsource the origination, packaging and servicing of all its personal loans, both old and new, one British bank cut the average cost of processing by over 75%. In the car industry in the 1990s, firms with the biggest profit per car, such as Toyota, Honda and Chrysler, were also the biggest outsourcers (sourcing around 70% to various suppliers). Those that outsourced the least (General Motors, for example, which outsourced only 30% of its value-added) were the least profitable.

The nature of outsourcing contracts has changed over time. What started off as a straightforward arm’s-length agreement between a buyer and a supplier moved on to become structured more like a partnership agreement. In this, not only is any increase in the clients’ volume of business reflected in the outsourcer’s scale of charges, but both parties in some way share the risks and rewards of the outsourced activity.

Relationships like this vary over time and require firms to learn how to work together in entirely new ways. In the early 1990s, in a groundbreaking five-year outsourcing agreement with BP, Accenture (then called Andersen Consulting) took over responsibility for running the day-to-day operation of BP’s accounting systems. BP retained control of accounting policy and the interpretation of data for business decision-making. In return, Accenture guaranteed BP that it would reduce the cost of running the service by 20%.

Some firms have been so taken with the idea of outsourcing that they have left themselves with little to do. An American company called Monorail Computers outsourced the manufacture of its computers as well as the ordering, delivery and the accounts receivable. Only the design was left to be handled in-house.

Further reading

Aalders, R., “The IT Outsourcing Guide”, John Wiley & Sons, 2001

Magretta, J., “What Management Is: How It Works and Why It’s Everyone’s Business”, Free Press, New York, 2002; Profile Books, London, 2003

Shenzhou VII spaceship lands safely

Shenzhou VII spaceship lands safely

(Agencies/chinadaily.com.cn)
Updated: 2008-09-28 17:53

BEIJING -- The Shenzhou-7 space module carrying three astronauts landed safely by parachute Sunday afternoon in China's northern grassland, after a landmark spacewalk mission that leads the country further in its space exploration.

The re-entry capsule of the China's Shenzhou VII spaceship is seen before landing on the grassland of North China's Inner Mongolia Autonomous Region, September 28, 2008. [Xinhua]

Astronauts Zhai Zhigang, Liu Boming, and Jing Haipeng came back from a 68-hour flight, which included a 20-minute spacewalk on Saturday.

"It was a glorious mission, full of challenges but the result is perfect. I'm proud of my country," said Zhai Zhigang, sitting on a chair after emerging from the module.

The space capsule was suspended down by a 1,000-square-meter parachute and landed on its flank at Siziwang Banner in central Inner Mongolia, where 300 search and rescue staff waited.

Premier Wen Jiabao, who arrived at the control center to watch the landing, clapped hands and beamed with smile when watching the spacecraft touch the ground.

The taikonauts were examined by doctors and adapted themselves to the gravitation on the Earth before exiting the module, the search headquarters told Xinhua.

They will be taken to a hospital in the Inner Mongolian capital Hohhot for medical examination and are scheduled to fly back to Beijing on Monday. The trio have to spend about two weeks in quarantine before meeting their family, said Zhai's wife Zhang Shujing.

The three men, all born in 1966, were blasted off at 9:10 p.m. on Thursday on the country's third space crusade. China put a lone Yang Liwei in space in 2003, and sent two men on a five-day journey in 2005. The successful spacewalk mission makes China the third to master the extravehicular activity (EVA) technology following the United States and Russia.

In this video grab from China Central Television, Chinese astronauts are seated in front of the re-entry capsule of the Shenzhou VII spaceship afer landing safely in North China's Inner Mongolia Autonomous Region, September 28, 2008. [Xinhua]

During the spacewalk on Saturday, Zhai wore a hulking 4-million-U.S.dollar homemade Feitian space suit and spent 20 minutes outside the spacecraft. Tethered to the craft with two safety wires and a long electric cord providing oxygen and communications, he moved slowly along a set of handrails around the orbital module.

"Shenzhou-7 is now outside the spacecraft. I feel well. I am here greeting the Chinese people and people of the whole world," Zhai said. He waved a Chinese flag handed over by his companion Liu Boming, who helped the "walk" in the orbital module.

Later Zhai retrieved a test sample of solid lubricant placed outside the orbiter, as part of an experiment to test the durability of the materials.

After the spacewalk, he was congratulated by Chinese President Hu Jintao, who watched live transmission of the spacewalk from the Beijing control center. Hu hailed the spacewalk as a breakthrough and thanked the taikonauts for their devotion and excellent performance. He inquired the taikonauts of their health and lives in space through a phone.

Other tasks of the mission included carrying out trials of satellite data relay and releasing a 40-kilogram companion satellite, which was left in the space with the orbital module and the extravehicular space suits.

The live telecast of the historic moment was watched by tens of millions of Chinese and met with applauses and cheers by crowds before downtown outdoor screens and office television sets.

hinesische Raumfahrt

Die Erde hat die Taikonauten wieder

Das chinesische Raumschiff „Shenzhou 7“ ist wieder zurück auf der Erde. Die drei Astronauten landeten in der inneren Mongolei im Norden Chinas.

Jing Haipeng, Zhai Zhigang und Liu Boming sind wohlbehalten gelandet

Das chinesische Fernsehen zeigte Live-Bilder der schwebenden Kapsel an einem großen Fallschirm, bevor sie in der Nähe des geplanten Landeplatzes aufsetzte. Das Raumschiff habe den gefährlichen Wiedereintritt in die Erdatmosphäre gut überstanden, berichtete die Nachrichtenagentur Xinhua. Auch seien die Astronauten bei guter Gesundheit. Während des Raumfluges hatte Kommandant Zhai Zhigang den ersten Weltraumspaziergang eines chinesischen Astronauten unternommen, Proben gesammelt und einen kleinen Satelliten ausgesetzt.

ZUM THEMA

Weltraumspaziergang:
Chinesischer Taikonaut sicher zurück

Raumfahrt:
Überirdische Machtdemonstration

Aufbruch ins All:
Ein Blick zurück

Die Freude über den geglückten Weltraumspaziergang am Samstag war groß. Ganz ohne Schrecksekunden lief er jedoch ab. Ein Feueralarm im Orbiter sorgte für einige Aufregung, wie die Bodenkontrolle enthüllte. Ursache sei die Fehlermeldung eines Sensors gewesen, berichtete ein Sprecher des Raumfahrtprogramms, Wang Zhaoyao. „Wir waren ziemlich nervös, als der Astronaut in der Rückkehrkapsel den Feueralarm berichtete.“ Doch hat sich die Aufregung nach seinen Angaben sofort gelegt, als klar wurde, dass der Alarm aus dem Orbiter kam, in dem gar kein Feuer ausbrechen konnte, weil er während des Ausflugs ins All keinen Sauerstoff enthielt und in einem Vakuum war.

Feueralarm während Außeneinsatz

Vor der Rückkehr von „Shenzhou 7“ zur Erde hatte die Bodenkontrolle mit dem ausgesetzten Satelliten untersucht, wie sich zwei Himmelskörper kontrollieren lassen, die dicht beieinander sind. Auch Tests zur besseren Datenkommunikation über das Netzwerk von Satelliten und Beobachtungsstationen wurden abgeschlossen. Es war das erste Mal, dass China einen Satelliten von einem Raumschiff aus in eine Umlaufbahn gebracht hat. Der mit Kameras und Kommunikationsausrüstung ausgestattete Satellit soll bei künftigen Raumflügen helfen, Daten weiterzugeben und Andockmanöver zu verfolgen.

hb/dpa

Wirtschaft

Konzern weiht Werk in Tianjin ein

Airbus made in China

[Bildunterschrift:Feierlicher Startschuss: Hier fotografieren sich zwei Hostessen vor einem Plakat, auf dem die Zeremonie angekündigt wird.]
Airbus hat seine erste Produktionslinie außerhalb Europas im chinesischen Tianjin eingeweiht. In dem neuen Werk rund 100 Kilometer östlich der Hauptstadt Peking sollen die Arbeiter Bauteile für A320-Maschinen aus den europäischen Werken - vordere und hintere Rumpfsektion, Tragflügel, Seiten- und Höhenleitwerk sowie Triebwerksaufhängung - montieren. Ab 2010 sollen dann vier Maschinen im Monat gebaut werden, hauptsächlich für den chinesischen Markt. Bis 2016 sind insgesamt 300 Maschinen geplant.

Hoffen auf größere Marktanteile

[Bildunterschrift:Airbus-Chef Enders (links) und der chinesische Premier Wen bei der Werkseröffnung in Tianjin]
Der Bau des Werks war gleichzeitig mit einer Großbestellung vor zwei Jahren vereinbart worden. Damals hatte China 150 A320 bestellt, unter anderem für Sichuan Airlines, an die die erste Maschine aus Tianjin im ersten Halbjahr 2009 ausgeliefert werden soll. Airbus erhofft sich von dem Werk, an dem der Konzern 51 Prozent der Anteile hält, einen größeren Marktanteil in China. Das Land gilt bisher als traditioneller Boeing-Kunde. Der Marktanteil der Europäer liegt zurzeit bei rund einem Drittel, während Airbus weltweit bei Großflugzeugen etwa die Hälfte des Marktes bedient. Bestellungen aus China machen bisher rund 15 Prozent der Airbus-Aufträge aus. Kritiker der China-Entscheidung befürchten, China sei vor allem am technischen Know-How der Europäer interessiert, um dadurch die Pläne für ein eigenes Großflugzeug schneller verwirklichen zu können.

Airbus rechnet mit neuen Aufträgen

[Bildunterschrift:Die Montagelinie in Tianjin ist ähnlich aufgebaut wie die in Hamburg]
Bei der Eröffnungsfeier waren Chinas Regierungschef Wen Jiabao und Airbus-Chef Thomas Enders anwesend. Enders sagte, er rechne mit "umfangreichen Bestellungen" aus China noch bis Anfang 2009. Der Flugzeugbauer habe bereits entsprechende Übereinkünfte mit chinesischen Unternehmen für insgesamt 280 Maschinen unterzeichnet. Nach seiner Einschätzung wird China in den kommenden 20 Jahren bis zu 3000 neue Großflugzeuge benötigen. Frühere Airbus-Schätzungen waren von 2700 neuen Passagierflugzeugen ausgegangen.

• China will Boeing und Airbus Konkurrenz machen (22.03.07).
• China ordert 150 Jets bei Airbus (26.10.06)