Slashdot Mirror


User: friedmud

friedmud's activity in the archive.

Stories
0
Comments
825
First seen
Last seen
Profile
(view on slashdot.org)

Comments · 825

  1. Re:Benchmarks are bad metrics on Samsung Fudging Benchmarks Again On Galaxy Note 3 · · Score: 1

    As an aside - we just bought a couple of OCZ Revodrive 3 x2 (1TB each) cards and have been using them and benchmarking them over the last couple of days for scientific data analysis... DAMN they are fast! We're getting about 1.2GB/s (yes Bytes with a big B!) consecutive reads (which is was our main purpose happens to be).

    The only downside we've found is spotty Linux (which, along with OSX is all we use... no Windows here) driver support. We have to actually use the commercial drivers for the Vertex and ZDXL... which are only precompiled for specific Linux kernel versions. Other than that the cards have worked great!

    A bit back on topic - if this "turbo" mode were something any app could invoke somehow (with an API call for instance) then this wouldn't be a problem... but since they've only made it work with explicitly named executables it feels a bit underhanded....

  2. Simulation Visualization on Data Visualization: Too Easy To Be Too Slick? · · Score: 1

    I write massively parallel scientific simulation software for a living (the kind that runs on the biggest machines in the world)... and trying to come up with a way to display GBs or TBs of information from some of our largest simulations can be _tough_.

    We use several open source packages ( Mostly http://www.paraview.org/paraview/resources/software.php and https://wci.llnl.gov/codes/visit/ ), but most of our best visualizations are actual done using a commercial package ( http://www.ceisoftware.com/ )

    For some examples check out the YouTube video here: http://www.youtube.com/watch?v=V-2VfET8SNw

    (That's me talking in the video). Those aren't necessarily our best visualizations - just some that happen to be on YouTube...

    We find that the reactions to these simulations are mixed. They are certainly eye-pleasing... but sometimes if you go too far in making it look good it can actually turn scientists off. They will start to think that it looks "too good to be true" (I literally had a senior scientist in a room of 200 stand up at the end of one of my presentations and proclaim that "This is too good to be true!"). Because of this we try to do do just enough visualization that you can see all of the features of the simulation and understand what's happening without going overboard.

    You have to realize that a lot of scientists still remember the days when they created line plots _by hand_ for publications! I suspect that as young scientists come up through the ranks this feeling that "slick graphics = not real" will go away.

    At least, I hope....

  3. Re:Government Labs on Ask Slashdot: Scientific Research Positions For Programmers? · · Score: 1

    Whoops - wasn't logged in.... this was me...

  4. Re:'Simple really... on Google Glass: What's With All the Hate? · · Score: 1

    Google Glass actually _helps_ here. If you were wearing one then you can show them exactly where you were at that time....

    This is essentially "counter" surveillance that can prove all sorts of stuff about your innocence.

    Have you seen all of the videos of Russion car dashcams? Do you know why they have those? To _protect_ themselves from the police (and other drivers).

    The principle is the same here...

  5. Re:sounds like someone is following this thread on Google Acquires Kite-Power Generator · · Score: 1

    I'm with you Intrepid - I've seen this lately too. Is this the new "Hot Grits!", are we being actively trolled or is this happening by chance?

    Whatever it is, I'm pretty tired of it....

  6. Re:My theory on Windows 8 Killing PC Sales · · Score: 5, Informative

    This pretty much means you aren't in any industry that has government contracts

    Not true. I work for a government research lab and we switched to GMail last year. Check it out: https://www.google.com/enterprise/apps/government/

  7. Re:A pellet stress simulation? on First Petaflop Supercomputer To Shut Down · · Score: 1

    Pellets, as manufactured, are _very_ smooth. This is a decent overview I just found from Google: http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Conversion-Enrichment-and-Fabrication/Fuel-Fabrication/#.UVmkjas5yZc

    They start life as powder and then are packed in a way that makes them smooth.

    However, just as in any kind of manufacturing: defects happen. A working reactor will have over a million pellets in it. Somewhere in there one is going to be misshapen.

    Some of what we can do is run a ton of statistically guided calculations to understand what kind of safety and design margins need to be in place to keep problems from occurring. We can also look at modifying the design of the pellets to insure safer operation. Both of these things are very difficult (and costly) to do experimentally.

    My lab (INL) does a lot of experimental fuel work... but we use these detailed simulations to guide the experiments so we can use our money more wisely. It literally takes years to develop a new fuel form, manufacture it, cook it in an experimental reactor, let it cool down, slice it open and see what happened. Using these detailed simulations we can do a lot of that "virtually" to help them decide on experimental parameters so that at the end of that whole sequence they have a bunch of _very_ good experimental results instead of half of them just being failures...

    Also, we do actually have a bunch of detailed experimental results to compare our simulations to. Even with this fidelity of modeling we are still not able to perfectly capture what happens in all of those experiments. Even more detailed models (like the multiscale one in the video) need to be developed to be able to truly predict all the complex phenomena that goes on in nuclear fuel.

    There is still a LOT more work to do...

  8. Re:A pellet stress simulation? on First Petaflop Supercomputer To Shut Down · · Score: 1

    Thanks!

    Certainly the nuclear reactor industry has done "just fine" without these detailed calculations for the last 60 years. Where "just fine" is: "We've seen stuff fail over the years and learned from it and kept tweaking our design and margins to take it into account". They have use simplified models to get an idea of the behavior and it has worked for them (as far as the reactors run safely and reliably).

    However, the "margins" are the name of the game here. If you can do more detailed calculations that take into account more physics and geometry you can reduce the margins and provide a platform for creating the next reactor that is both more economical and safer. If you can increase the operating efficiency of a nuclear reactor by even 1% that is millions of dollars. If you can keep something like Fukushima from happening that is even more money (some would say "priceless").

    The approximate answers (using simplified models) are good - they are in the ballpark. But if you compare their output to experimental output (which we have a LOT of... and it is VERY detailed) the simplified models get the trends right... but miss a lot of the outlier data. That outlier data is important... that's where failure happens. With these detailed models we get _much_ closer to the experimental data.

    To get even closer to the experimental data we have to get even more detailed. The movie showed some of our early work in multi-scale simulation: where we were doing coupled microstructure simulation along with the engineering scale simulation. That work is necessary to get the material response correct to get even closer to the experimental data.

    Ultimately, if we can do numerical experiments that we have a great amount of faith in, it will allow us to better retrofit existing reactors to make them more economical and safe and design the next set of reactors.

  9. Re:A pellet stress simulation? on First Petaflop Supercomputer To Shut Down · · Score: 1

    See my response above about the fidelity of the calculation.

    Industry has been chomping at the bit for decades to get to detailed calculations like this. If you can save a nuclear reactor 1% of their operating cost... that is millions of dollars. Higher fidelity = more money in our economy.

  10. Re:And it didn't need to be on First Petaflop Supercomputer To Shut Down · · Score: 2

    I know I shouldn't respond to AC's but I'm going to anyway:

    And it didn't need to be.

    As far as geometry goes, it did need to be that detailed. Firstly, the pellets are round and to get the power and heat transfer correct you have to get the geometry correct. Also, pellets have small features on them (dishes on top and chamfers around the edges) that are put there on purpose and make a big difference in the overall response of the system (the dishes, in particular, reduce the axial expansion by a lot). So the detailed geometry is a very important part of this simulation. But that's not the only reason why it's large.

    Your simulating a simple heat transfer and simple expansion, NOTHING MORE, no different that any other chemical process simulation in any other factory. Just with a lot more nodes.

    I already explained how that is not the case. These are fully-coupled, fully-implicit multiphysics calculations. It is _not_ just heat conduction going on. Very complicated processes like fission gas creation, migration and release and fission induced and thermal creep, and fission product swelling are all involved. Plus the heat conduction and solid mechanics and thermal contact and mechanical contact and fluid flow model (on the outside of the pin) and conjugate heat transfer. All of these processes feed and are impacted by each other. These are NOT simple calculations.

    It's also an arbitrary simulation serving no purpose. You said "what is that panel is broken right there' then ran a simulation with a stupid number of nodes to soak up a computer. But the pellet was made, it exists, it didn't need your simulation to be made and the simulation make zippo difference. You can run any number of similar simulations with the damage in an infinite number of places or combination of places, and it makes zip difference to the world because you don't know where each pellet is damaged. So NONE of your simulations apply to the actual pellet.

    Actually, you are very wrong. Firstly, the Missing Pellet Surface problem is a huge problem in industry. What we can do with simulation is explore boundaries of how much tolerance there can be for such missing surfaces. We can vary the missing surface size and run thousands of calculations to determine the sizes that operators need to worry about. They can then adjust their QA practices to take this information into account. We can also run simulations of full reactors and stochastically sprinkle in defect pellets and show the overall response of the system which can help in understanding how to bring a reactor back up to full power in a safe way after refueling.

    As for "that pellet exists"... firstly that's not true... but even if it did, doing experiments with nuclear fuel is _very_ costly and takes years (that is something else we do at INL) in order to better target our experimental money we do simulation to guide the experiments.

    Their mission statement is absolutely clear. Turn cold war spending into security theatre spending and that's your job.

    I don't work in security.... there are many national labs, all with different missions, but they _all_ do non-security work. They all work with US industry to solve some of the toughest problems on the planet. They are all full of extremely smart people and they are all working to add to the competitive advantage of the US. I'm sorry that you feel that way, but if you are interested in learning more about the national labs you should get a hold of me.

  11. Re:A pellet stress simulation? on First Petaflop Supercomputer To Shut Down · · Score: 5, Informative

    I don't get it are you looking for a Funny mod? You linked to a 2D heat transfer simulation done by Matlab. Did you even watch the video?

    The second simulation (of a full nuclear fuel rod in 3D) was nearly 300 million degrees of freedom and the output alone was nearly 400GB to postprocess. It involves around 15 fully coupled, nonlinear PDEs all being solved simultaneously and fully implicitly (to model multiple years of a complex process you have to be able to take big timesteps) on ~12,000 processors.

    Matlab isn't even close.

  12. Re:throw away mentality (actual arcticle link) on First Petaflop Supercomputer To Shut Down · · Score: 4, Interesting

    It costs a _lot_ to keep these computers running (read Millions with a really big M). The power bill alone is an enormous amount of money.

    It literally gets to the point where it is cheaper to tear it down and build a new one that is better in flops / Watt than to keep the current one running.

  13. Re:Top supercomputer is Google? on First Petaflop Supercomputer To Shut Down · · Score: 5, Informative

    I've worked for the DOE for quite a few years now writing software for these supercomputers... and I can guarantee you that we use the hell out of them. There is usually quite a wait to just run a job on them.

    They are used for national security, energy, environment, biology and a lot more.

    If you want to see some of what we do with them see this video (it's me talking):

    http://www.youtube.com/watch?v=V-2VfET8SNw

  14. Re:No shit on HBO Says Game of Thrones Piracy Is "a Compliment" · · Score: 1

    I want to watch it in hi-def. I don't own a Blu-Ray player as I've never needed one.

    You want hi-def... therefore you now need a Bluray player... simple.

    BTW - The Blurays of GOT are _awesome_. The video and audio quality are REALLY good and the commentary and special features are also completely worth it.

    I subscribe to HBO on my Dish... but I have also purchased both of the seasons of GOT on Bluray. They are epic.

    Can't wait for the new episode tonight!

  15. Re:maximum visual working set on Ask Slashdot: What Is Your Favorite Monitor For Programming? · · Score: 1

    Obviously, you want screen and not frames in your most valuable view area - the center - which means you have to go for a single screen.

    Or _three_ (so one is in the center). Three 30" monitors is ideal.

  16. Go Big on Ask Slashdot: What Is Your Favorite Monitor For Programming? · · Score: 1

    I use three 30" (2560x1600) Dell Monitors hooked up to my Mac Pro workstation (it has an ATi graphics card that can drive 3 natively so it's smooth as butter).

    In this configuration I can stretch an Emacs window across the left two and split it into 6 vertical segments (with one horizontal split along the bottom for utility functions). On the right monitor I keep a tabbed Terminal taking up half and a tabbed browser taking up half each of those generally has 6+ tabs open at any one time (make sure your Terminal tabs get named by the directory they're in!).

    I've been working with three monitors like this for about a year and half now... and I highly effective with it.

    The trick to using 6 panes of source code at once? Organization. I have set guidelines about what files get opened where (I work left to right from lowest level library to highest level application)... this lets me always know where to look.

    I don't know if I could go back to "just" two 30"ers....

  17. Re:An Apple for an Apple on Apple v. Samsung Jurors Speak, Skipped Prior Art For "Bogging Us Down" · · Score: 1

    Violence against people because of their choice of a phone?

    Wow. Just. Wow.

    It is one thing to champion a free OS... or talk about the upsides of an open ecosystem... but you are truly unbalanced to suggest open hostility towards people who don't share your views.

    Also... what exactly is it that makes you like Samsung so much? They are every bit as much of an "evil corporation" as Apple... and depending on which report you're reading at the moment could be considered much worse...

  18. Re:mo' money on Apple v. Samsung Jurors Speak, Skipped Prior Art For "Bogging Us Down" · · Score: 1

    I keep seeing this but I don't understand. How is it a "loss" that people can't just make copycat products?

    Wouldn't that be a "win" because we want each individual company to try out innovate each other instead of just giving us "low rent" knockoffs?

    I just don't get...

  19. "the solution should be to fix the law-making process"

    If only that were possible. It's simply not. Humans and human activities are too diverse to be able to make "perfect laws". The idea of a jury is to interpret the best laws we can make for the particular circumstance in the case.

    If you think you can get 9 people to agree to "reverse vigilantism" then we have bigger problems in this country anyway...

  20. Why do you want to go to "personal comments"? I don't think I said anything too inflammatory... I merely suggested that I consent to the rule of law and the right of juries to interpret that law. I don't like the idea that Americans would automatically want to overturn the will of a capable jury. Juries are the things saving us from our own laws and lawmakers...

    I never said that they are perfection... and, in fact, that is the whole point of a trial "by your peers". Jury's are there to inject
    reality into our legal system. Laws are drawn up in a fairly closed off environment by people typically thousands of miles away... a jury is there to interpret that law _for the people_ at the most local level possible: on a case by case basis.

    We should really only question a few things about a jury. Did they properly represent "peers". Are they of sane mind. Were they tampered with?

    If the answers to these questions come back ok... then the will of the jury can be said to represent the puclic's interpretation of the law in this case. And that is what matters.

    This was, from my reading, a damn fine jury... it consisted of several people who work in the tech industry and a few who don't. It consisted of people with some knowledge in this area and some who don't. The fact that 9 people with this mix of backgrounds could agree that Samsung infringed... and did so _willfully_ speaks volumes.

    Juries are not perfect... but neither is the law. That's why we have juries to interpret the law and apply it to each case independently.

    If you have a problem with the verdict then you really have a problem with the law. Normal Americans were given facts and asked to interpret the law and this is the outcome. If you want to change the outcome in the future... then change the law.

    But for now, all procedures were followed and Samsung was found to owe Apple some cash according to the current laws.

  21. Re:we skipped that one so we could go on faster on Apple v. Samsung Jurors Speak, Skipped Prior Art For "Bogging Us Down" · · Score: 1

    Just means they moved on from that issue _for that moment_. Never does it say they never returned to it. This is pretty normal in any group debate. You fight for a while about an issue... then you move on to try to find some common ground somewhere else... the COME BACK to the first issue much later to make a decision.

    I really think these quotes are being taken out of context.

  22. Well... for a report that is a little more balanced see this CNN article:

    http://news.cnet.com/8301-13579_3-57500358-37/exclusive-apple-samsung-juror-speaks-out/

    What is this world coming to when we want to "invalidate" the findings of a jury? What is the purpose of law and trials and jury if we're just going to "overturn" any ruling that is unpopular?

    Why did it need to take _days_ for the jury to find in this case? This isn't a murder trial without a murder weapon. Nor is it some complicated manslaughter case involving cell-phone use while driving... or any other type of "grey area" type case with dire consequences of getting it wrong.

    The jurors sat there for _weeks_ listening to this stuff. Do you not think that in that time they were able to form an opinion and when it came time to make a decision there was a bit of heated debate until everyone agreed and then they ruled? What exactly were they supposed to talk about for so long? The considered all the evidence (and had been considering it for weeks... this is ALL they were doing for _weeks_) and came to a conclusion.

    Quit letting your own personal biases against patents and closed source / closed ecosystems get in the way of believing that a jury of, by all accounts very capable, people could rule in favor of Apple. The law is the law... this group of people think the law is in favor of Apple. That is all. Nothing more...

  23. Re:Advice on English Prepaid SIM on Mobile Operator Grabs 4G Lead In UK — But Will Anything Work On It? · · Score: 1

    lol - well... I have work in the area but my wife is going with me to see some parts of the UK we haven't seen yet. I don't know that Preston would have been our first choice for going back to the UK... but the decision was made for us.

    Thanks for the info on 3!

  24. Re:Advice on English Prepaid SIM on Mobile Operator Grabs 4G Lead In UK — But Will Anything Work On It? · · Score: 1

    Thanks for the pointers... it's looking like 3 is the way to go. They have a £10 pay as you go plan that comes with 500MB of data. Sounds perfect for a couple of weeks and it looks like they have decent coverage where I'll be...

    Anyone have specific experience with 3 in the Preston/Blackpool area?

  25. Advice on English Prepaid SIM on Mobile Operator Grabs 4G Lead In UK — But Will Anything Work On It? · · Score: 0

    I'm headed to England soon for vacation and need some advice on prepaid SIMs. I'm going to be mostly in the Blackpool/Preston/Manchester area... I'm going to have my first gen iPad with me which I successfully ran on a 3G prepaid SIM in Australia last year and I'd like to do that again.

    Anyone have some advice on what service to go with in that area of England? I don't need anything crazy... just a couple of gigabytes total will work.

    Thanks!