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Jonathan Dursi
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Jonathan Dursi

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An enemy #HPC and Mars Curiosity have in common - cosmic rays, with Error Correcting Memory to the rescue. (h/t @beckersweet) http://ow.ly/cXIhT
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Jonathan Dursi

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Two vortex rings collide head-on in this video. If their vorticities and velocities are matched in magnitude and opposite in direction, their collision results in a stagnation plane—essentially a wall across which the fluid does not pass. In reality, there are slight variations that result in non-zero velocities where the vortices meet, so some mixing occurs, but the overall symmetry remains striking. The collision breaks up the vortex ring into ...
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Tough crowd! Yes, sure, but to get to vorticies to exactly cancel out like that, and then those spectacular secondary eddies appearing... Spectacular! But maybe I'm just a fluids geek.
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The US Departement of Energy Magellan project, a pilot project for using cloud computing for science, has issued its final report:

http://science.energy.gov/~/media/ascr/pdf/program-documents/docs/Magellan_Final_Report.pdf

As a cloud computing cynic (or, more generally, a Latest Big Buzzword cynic), it's hard not to feel a little vindicated. It turns out cloud computing, while having some advantages for some workflows, is not magic, and current cloud computing stacks are designed for random web-based stuff, not scientific computing. A not entirely unfair summary of the high points:

* Current big research computing centres already often have the economy-of-scale advantages of cloud computing, and in fact are generally cheaper (and come with real scientist support).

* Current public cloud offerings work fine as long as performance doesn't matter.

* Being able to roll your own image can be helpful for some scientists: but then, either
(a) you're offloading a lot of sysadmin duties off to the scientists, who now have to know enough about sysadmining their OS of choice to be able to roll a correct and complete OS image from scratch just to run the couple of programs they want to run; and/or

(b) you encourage sharing of images, which are then
i. "kitchen sink" huge images which contain tonnes of stuff unnecessary for any particular job, and
ii. prone to different types of security issues. ("Use my new compute image for quantum bogodynamics! I promise it hardly ever emails copies of all your private data to me!")
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And to you!
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The villagers of Gourdville fled in terror from the giant monster; but sadly, not all would escape in time.
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Tragically, only the hip will escape from Gourd Downey's town.
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What a great idea! The Canadian Young Scientist Journal is run by a high-school teacher here in Toronto, and is a peer-reviewed science journal for high school students who are involved in real research projects, often with University research groups. Go to the website and look at some of the abstracts - "Nuclear Steam Waste Reused"; "Design and Application of a Cell Phone-Compatible Wireless Stethoscope" - this is great stuff.

One benefit of course is that it gives students a chance to get the experience of writing up results and getting it through review (and their acceptance rate is not high; even so, they get submissions from the US and even further abroad).

But the most important benefit, I think, is that it is sent to every school in the country, so that other high school students can see what their peers are doing and be inspired to try doing similar things. That's terrific.

But all that printing and distribution is costly, and they are having a hard time continuing to get sponsorships in the present environment.
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Have him in circles
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Jonathan Dursi

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Trying to eke an extra year or two worth of useful life from my 2007 Macbook pro through upgrades; replaced hard drive with a (somewhat larger) SSD, and maxed out the ram. Starting up programs definiately much faster, and I'm obviously swapping less now (and hurt less badly when I do). Seems like a decent investment so far...
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No, battery life is pretty poor, but after 2000+ cycles, that's probably to be expected. I should get another battery, but now that I have my tablet I mainly use this laptop as a "portable desktop" and it doesn't cause me enough problems to bother...
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This is fantastic news. StatsCan is a really sharp bunch of people and they have tonnes of amazing data. While they'll lose the income from institutions, hopefully the visibility that their work receives as a result will increase support for their mission which will eventually increase their funding. Maybe one day we'll even have a government which un-breaks the census as a result...
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Cray takes over Blue Waters -- very interesting. I'm at #sc11 learning about Chapel and XE6, and I have to say I'm fairly impressed by both.
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Who's all there from SN? I think Alex is supposed to be there, but John's been giving me the silent treatment...
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Huh; I've been acknowledged ("We thank ... [more deserving names elided] ... J. Dursi ... for their advice and assistance on plant genome assembly") in that widely talked about recent paper on the transcription of the genome for cannibis sativa (yes, that cannabis). I'm not sure I did much to earn that acknowledgement -- but even so, I guess I've come a long way from doing just astrophysical fluid dynamics.
Cannabis sativa has been cultivated throughout human history as a source of fiber, oil and food, and for its medicinal and intoxicating properties. Selective breeding has produced cannabis plants for ...
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I was at a meeting this morning with researchers from four departments across two Universities. Every single computing device that was pulled out was an Apple machine; beat-up looking macbook pros which had seen the world, a few newer pros, a macbook air, and an iPad and iPad 2. This isn't unusual.

I remember when this change started happening in my field (computational Astrophysics); in the late 90s, going to conferences you'd see mostly linux laptops, with a smattering of Windows laptops (mostly amongst older PIs). Then the first macbook pro came out and suddenly, within the space of two years, the macs were the vast majority at these conferences.

These are people who take their computation very seriously; who have linux on their desktops and clusters, and often have root on them. People who worry about performance and cost effectiveness of large-scale computing solutions. But when they're on the road, giving talks or taking notes or doing a little work between (during?) talks, they really wanted the power they were used to in a package that "just worked". And when such a thing became available, the speed of uptake was amazing. An entire research community switched their hardware as soon as they could.

Steve Jobs' Apple changed how I and my colleagues worked, making us more productive and letting us have a little bit of fun while we did it. Thanks for helping us think different about our computing, Steve.
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We at SciNet will be mentoring up to 6 Toronto-area high school students in the basics of supercomputing for science and innovation - students will learn how to build a supercomputer in an office, and how to program several computers to work together on one problem. Know anyone that might be interested? Application deadline is October 21.
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Have him in circles
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Computational Science, HPC, & Parallel Programming, Advocacy and Practice
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HPC for computational science and innovation.
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halifax, ns - kingston, on - chicago, il