You need to install nautilus image converter:
sudo aptitude install nautilus-image-converter
You’ll need to restart nautilus. One option is logout and back in.
You’ll be able to right-click on any image on your machine and you’ll see two new menu items:
resize images
rotate images
By STEVE LOHR from nytime.com
Any conversation with Tim Berners-Lee, the creator of the Web’s bedrock software standards, tends to be fast-paced and nonlinear. When he worked at the CERN physics laboratory in Geneva, colleagues tried to get him to speak French instead of English, in hopes of slowing him down.
No surprise, then, that a half-hour dialogue with Mr. Berners-Lee, director of the World Wide Web Consortium and these days a professor at M.I.T., at a symposium on the future of technology last Thursday, fit that mold. I started, just for fun, with a historical question. If he were do it over again today, would he do anything differently? Any regrets?
Mr. Berners-Lee smiled and admitted he might make one change — a small one. He would get rid of the double slash “//” after the “http:” in Web addresses.
The double slash, though a programming convention at the time, turned out to not be really necessary, Mr. Berners-Lee explained. Look at all the paper and trees, he said, that could have been saved if people had not had to write or type out those slashes on paper over the years — not to mention the human labor and time spent typing those two keystrokes countless millions of times in browser address boxes. (Today’s browsers, of course, automatically fill in the “http://” preamble when a user types a Web address.)
With history dispatched, Mr. Berners-Lee focused on his current enthusiasm — getting more government data on the Web, in the interest of openness, transparency and efficiency. Mr. Berners-Lee is working with the British government in its efforts to do so, and at the symposium he cited some favorite examples of benefits of simple mash-ups like combining roadway maps with bicycle accident reports. The result, he said, helps bikers know which roads to avoid to reduce their chances of being hit by a car.
In a separate interview at the symposium in Washington, sponsored by the Finnish government and the Technology Academy Foundation, Mr. Berners-Lee said this was the year when governments around the world, led by Britain and the United States,are beginning to put vast amounts of information they collect on the Web. It is often seemingly mundane data in raw form, he said, including traffic, local weather, public safety and health data.
But the lesson of the Web, Mr. Berners-Lee said, is that making information and simple online tools freely available inevitably fuels innovation. If you liberate the data, he asked, who knows what applications people will create?
“Innovation is serendipity, so you don’t know what people will make,” he said. “But the openness, transparency and new uses of the data will make government run better, and that will make business run better as well.”
A new MIT programming tool would automatically plug holes that hackers exploit.
Larry Hardesty, MIT News Office
More and more, malicious hackers are exploiting web site security holes to attack their victims’ computers. Programmers try to identify those holes in advance and plug them with code that performs security checks; but if they find a hundred holes and miss one, their programs are still insecure. At next week’s ACM Symposium on Operating Systems Principles, however, MIT researchers will present a new system called Resin, which automatically calls up security checks whenever they’re required, even in unforeseen circumstances.
Typically, web programmers will associate security checks with particular application functions. If you belonged to a social-networking site, for instance, you might be able to e-mail your friends, or post remarks on their pages, or comment on their own posts, or tag their pictures, and so on. Each of these operations executes its own chunk of code, and the developer will usually attach a security check to each chunk, to ensure that the user is authorized to invoke it. (These types of security checks operate in the background: they don’t require you, for instance, to reenter your user name and password.) Many web applications also “sanitize” data posted by their subscribers: if a friend posts something to your social-network page, the application probably won’t show you the post without inspecting it for malicious code.
“We’ve looked at a lot of these web applications, and there’s literally hundreds of places where these checks happen,” says Nickolai Zeldovich, an assistant professor in MIT’s Computer Science and Artificial Intelligence Lab. Indeed, Zeldovich and his colleagues identified one popular web application that sanitized data in more than 1,400 places (but still had about 60 security holes).
They also, however, identified a feature that web application security checks usually had in common: “Namely,” Zeldovich says, “it’s that the same data is being handled in all these hundreds of places.”
So Zeldovich, grad students Alexander Yip and Xi Wang, and Professor Frans Kaashoek developed a system that associates security checks with particular chunks of data rather than with particular chunks of code. Any attempt to access the data, by any imaginable route, invokes the check.
The researchers modified 12 existing applications written in the popular web programming languages Python and PHP so that they used the Resin system. In experiments, the modified applications repelled attacks that exploited known security holes. But the researchers also developed their own attacks, which Resin thwarted as well.
For programmers, the new system should be easy to adopt. They’re already writing code for security checks and sanitization anyway; now, they’d have to write it only once, instead of pasting it into their programs in hundreds of different places.
But the MIT system relies on additional software that tracks data as they flow through an application, to make sure that security rules remain associated with the information wherever it’s being stored and however it’s being used. And the data tracker presents the biggest obstacle to commercial adoption.
Web applications need to run on any type of computer, regardless of the operating system or web browser being used, so web languages like Python and PHP require an extra layer of software called a “runtime” to translate code into the language spoken by a given machine. Generally, the organizations that develop new programming languages also maintain the runtimes, which undergo sequential releases, just like any commercial program. The MIT system’s data tracker would have to be incorporated into several different languages’ runtimes, which could be a hard sell.
“At least in PHP, the focus tends to be on performance,” says Eddie Kohler, an assistant professor of computer science at UCLA. Resin, Kohler says, “shows that you can do it without too much of a performance loss,” but “it’s not zero; it’s not a performance gain.” Kohler points out, however, that Resin could gain traction with the runtime gatekeepers if it first proves itself in some particular, real-world instances. “A place like, maybe Facebook, say, that runs other people’s code on their servers already has an environment where they’re much more worried about people stealing data out of their servers than they are necessarily about getting the last two percent of performance,” Kohler says. “I expect that as it gets deployed, it would get deployed by individual companies first.”
If you are looking for a wide range of free courses offered online, MIT is your best option. More than 1,800 free courses are offered through the school’s OpenCourseWare project. Courses are in text, audio and video formats and translated into a number of different languages. Students all over the world use OpenCourseWare and 96 percent of visitors to this site say they would recommend it to someone else.
The Open University is the UK’s largest academic institution. The school’s OpenLearn website gives everyone free access to both undergraduate and graduate-level course materials from The Open University. Courses cover a wide range of topics, such as the arts, history, business, education, IT and computing, mathematics and statistics, science, health and technology.
Carnegie Mellon University offers a number of free online courses and materials through a program called Open Learning Initiative. OLI courses are intended to allow anyone at an introductory college level to learn about a particular subject without formal instruction. Course options include such offerings as statistics, biology, chemistry, economics, French and physics.
Like MIT, Tufts has OpenCourseWare that is available free to everyone. Courses are sorted by school (i.e. School of Arts and Sciences, School of Medicine, etc.) and include assignments, lecture notes and other supplementary materials.
Stanford University, one of the world’s leading academic institutions, has joined forces with iTunes U in providing access to Stanford courses, lectures and interviews. These courses can be downloaded and played on iPods, PCs, and Macs and can also be burned to CDs. If you don’t have iTunes, you can download it here for free.
UC Berkley, one of the best public universities in the nation, has been offering live and on-demand webcasts of certain courses since 2001. Hundreds of UC Berkley courses, both current and archived, are now available as podcasts and webcasts. Courses cover a range of subjects, including astronomy, biology, chemistry, computer programming, engineering, psychology, legal studies and philosophy.
Utah State University also provides access to free online courses. Study options include everything from anthropology to physics and theatre arts. These comprehensive text-based courses can be downloaded as zip files or viewed directly on the site.
Kutztown University’s Small Business Development Center offers the largest collection of free business courses available on the web. Course topics include accounting, finance, government, business law, marketing and sales. Comprehensive text, interactive case studies, slides, graphics and streaming audio help to demonstrate the concepts presented in each course.
The University of Southern Queensland in Australia provides free online access to a number of different courses through yet another OpenCourseWare initiative. Courses from each of the five faculties are available, covering a broad range of topics, including communication, science, career planning, technology, teaching and multimedia creation.
UC Irvine, one of the nation’s top public universities, recently joined the OCW Consortium and began providing free university level courses online. Right now, there are only a handful of options to choose from, but this list is growing. Current courses cover topics like financial planning, human resources, capital markets and e-marketing. Course materials include syllabi, lecture notes, assignments and exams.
By Susan Milius from sciencenews.org
Ecologists are taking a page, and its ranking, from Google.
A new algorithm inspired by the search engine works well for predicting which species losses will trigger the fastest collapse of a food web, says theoretical ecologist Stefano Allesina of the University of Chicago.
Food webs describe the pattern of what eats what in the neighborhood. If one kind of grass or bug, for example, disappears, creatures that fed on it would need to find something else for lunch. If they couldn’t, or if the alternative entrées went extinct too, then the loss could trigger a cascade of extinctions. Losing certain species can starve so many others that the whole food web unravels.
The new algorithm works much like PageRankTM, Google’s system for ranking the importance of Web pages. The food web version did a better job of predicting collapse than simply comparing the number of connections each species has with other species in the food web. The method also beat out analyzing the network to find hub species, Allesina and Mercedes Pascual of the University of Michigan in Ann Arbor report online September 3 in PLoS Computational Biology.
“The problem of how ecosystems are likely to respond to the loss of species is quite important, particularly in light of how many different ways human activities are resulting in the local extinctions of populations,” says computational ecologist Jennifer Dunne of the Santa Fe Institute in New Mexico. Global warming, the introduction of species such as the zebra mussel, development that destroys habitat, pollution and plenty of other menaces make food web vulnerability an urgent concern, she says.
Allesina got the idea for treating food webs like the World Wide Web while he was at the National Center for Ecological Analysis and Synthesis in Santa Barbara, Calif., and chanced upon a description of Google’s page ranking system. “I said, ‘That looks familiar,’’’ he remembers. In essence, the system calculates a page’s importance, or value to searchers, depending on the importance of the pages that link to it. Through the magic of mathematics, it works. In a food web, species draw importance from the importance of the species that eat them.
The Google ranking system, though, essentially assumes that any page might lead to any other page. But that doesn’t make sense for food webs. “Energy does not go from the grass to the lion without going through the zebra,” Allesina says. He and Pascual only made links between predator and prey. And for every species the researchers added a path to a “detritus pool.” All species can thus die, decay and become nutrients for plants or the other primary producers of food in the web.
Page ranking system inspires algorithm for predicting food webs’ vulnerability
To compare their algorithm with others, the researchers used information from real-world food webs. One of the other programs, called a genetic algorithm, provided a gold standard. The new algorithm matched the genetic algorithm’s results without its heavy computational demands, Allesina and Pascual report.
Dunne calls the approach a “novel, exciting contribution.” Now, she says, it would be interesting to try to bring the algorithm closer to real life by adding factors such as the relative amounts of energy flowing through the connections.
From Cordis – ICT Results
Part of the internet’s potential lies in its ability to link hundreds, thousands, or even millions of devices.
Whether a user is downloading a video from a peer-to-peer service, performing scientific research on a grid, or using “cloud computing” to manage a business, programs that let many devices and applications work together are crucial.
The problem, says Peter Van Roy, coordinator of the EU-supported SELFMAN project, is that it’s getting harder to keep those systems working.
“The central challenge when you build big internet applications is how to keep them running without having to tweak and manage them all the time,” he says.
The SELFMAN team set out three years ago to solve that problem by finding out how to build programs that take care of themselves in the rough-and-tumble internet environment.
“We wanted to make big internet applications easy,” Van Roy says, “so that all the management problems you normally have are handled by the system itself.”
The payoff, he says, will be huge. “It will take the internet to the next level.”
The SELFMAN researchers identified four vital functions for a distributed application to manage itself – self-configuring, -tuning, -healing and -protecting.
Software is continually being patched, updated or replaced. For a distributed system to configure itself, it needs to keep track of all its components, update them as needed, and make sure that all parts of the system can still talk to each other.
“Our system can ask a component, what version are you? Who are you talking to? It can then replace an old version with a new one as needed,” says Van Roy.
Self-tuning means that the system can instantly adjust to changing loads and to components leaving or joining the network.
“Suppose one node is getting overloaded,” says Van Roy. “Our load-balancing algorithm allocates new nodes close to that hotspot. It spreads the heat to the other nodes and the hotspot cools down.”
The internet is an unpredictable environment. Routers crash, cables get cut, parts of the system overload and grind to a stop, and components come and go.
“With SELFMAN,” Van Roy says, “each node stores some of the data and each piece of data is replicated a certain number of times. If a node crashes, the other nodes detect the crash, find a new node and give it the missing data. The system heals itself.”
One of the biggest problems SELFMAN tackled was self defence.
The researchers discovered that a system’s security depends on its topology – how nodes are linked to each other. They found that “small world” networks – in which most nodes are not directly linked, but in which any node can communicate with another in a few steps – were the safest.
“With a small world network, it’s easier to detect, isolate, and eject bad nodes,” says Van Roy. “The security service observes the system’s behaviour. If it notices that certain parts of the network are acting abnormally, it takes action.”
The SELFMAN team found that building these advanced capabilities into useful applications required a highly structured approach.
The foundation of each application is a structured overlay network. That’s a program – itself replicated across the network – that keeps track of all the nodes and connections between them, and can decide when and how to fix problems.
The next level is a replicated storage system. It makes sure that each node has access to the same data, and that data are always replicated to ensure they do not disappear.
The third level houses SELFMAN’s transactional problem-solver. It relies on a sophisticated algorithm called Paxos to provide a systematic way of reaching consensus among any number of fallible components.
Van Roy uses the analogy of a transfer between two bank accounts. “If you want to reduce one bank account by 100 euros and add that 100 to another, you want both or nothing,” he says. “Each node must see the same data.”
“Getting all this fluid behaviour – where even if nodes are crashing or new nodes are coming in or the network has problems it never blocks the system – was a big technical problem,” says Van Ray. “We needed Paxos to get it to work.”
The SELFMAN architecture and components have been used to build some impressive applications. These include a prize-winning distributed Wikipedia that can handle far more queries than the current version, a commercially successful media streaming service, and a graphics program that lets multiple users collaborate on a design.
Van Roy believes that SELFMAN opens the door to a host of high-powered, flexible, and “unbreakable” internet applications. “Right now we’re just scratching the surface,” he says.
Sites: http://www.ist-selfman.org http://cordis.europa.eu/ictresults IST Project Fact Sheet
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