2131 posts • joined Tuesday 24th April 2007 14:31 GMT
Re: Just found a problem with that subhead...
Or "Budget Suites in SPAAAAAAAAAAAACE!!"
Re: Dont purchase anything
You are right when talking about looking through CDs and glass blackened with soot. There are however perfectly safe solutions. My Thousand Oaks glass objective solar filter works fine on my 8" scope. I watched and photographed the solar eclipse in 1999 with that scope, and the previous transit of Venus in 2004. Baader Solar film is perfectly safe, if attached correctly in front of the objective lens. All eyepiece filters are an absolute menace. I have recently made a solar filter out of it for my kids 4.5" F/4.4 Newtonian, and my eldest son and I had a nice view of sunspots through it. All harmful UV is blocked, and the total energy levels remain quite low.
Projection is actually dangerous in most reflectors, and certainly Maksutovs, Schmidt Cassegrains, and other scopes with fast primary mirrors, as the secondary can shatter under thermal stress, and even in fast refractors I would prefer a filter as the thermal stresses might cause eyepieces to shatter. In slow refractors projection is fine, especially as multiple can watch simultaneously.
Re: Need help
"88 percent of respondents said they are willing to seek professional help to treat smut addicition, but would prefer to do it online;"
Well obviously they prefer to do it online, that was exactly the problem, wasn't it?
The technique worked here, because a body heated to 2000K emits copious amounts of IR (and even visible radiation. Move an object of the same size to an orbit with a more hospitable (at least for us) 273-300K, or roughly 7 times cooler, the same surface emits 7^4 =2,401 times less radiation (or 8.5 magnitudes lower). That would make a super Earth at room temperature much harder to spot against the glare of the star.
Darn, so I cannot use my Hercules graphics card after all
Speed limit on Autobahn? Only in some places. On most stretches they allow you to hit Mach 2. I once saw a video of a Renault Espace fitted with an F1 engine hitting 200 mph on a track. Perfectly OK for the German Autobahn.
The funny thing is most Germans support a 130 km/h speed limit, but that the car industry lobbies very successfully against it.
Re: serves him right
So the dog deserves to be shot for that?
Should have gone for
in damages, just for the sake of it.
Re: So how rare is this?
If only it were a one in a million chance, we would see them every time
A page out of Harry King's book!
Mine is the one with "The Truth" in the pocket
I can just hear a couple of surviving dinosaurs having a conversation
"When I was a lad, we proper fleas, not these miniature little things that cannot bit through a piece of paper if they wanted to!"
"Right you are! I remember fleas that could bite right through a Triceratops's scales, he could"
"That's nothing, I saw some fleas that could drill straight through an Ankylosaur's club, no less"
"Rubbish, we had fleas which could drill for oil, they could, bite so strong it would go a mile through solid rock, it could!"
"And the problem with kids these days is that when you tell them they don't believe a word you say!"
Prefer the Z-series
Came with better screens and nVidia graphics. Light machines which run CUDA stuff. Not cheap though. My even older Vaio SZ is still working, and even it can run more (older) CUDA stuff. No Ultrabook ticks that box.
Fortunately, there has been a spate of very decent 13" and 14" laptops with nVidia 520 and 540 graphics on board. Cheaper than the Ultrabooks too. So, guess what I will get to replace my crumbling SZ.
If you look carefully and from the right angle
The stars spell
So long, and thanks for all the fish
@ Some Beggar
What Wirth means is that for a given task, the current software needs vastly more resources (CPU and memory alike) than similar software years ago.
Why is this worrying? Because it suggests that we could get by on much leaner compute capacity for many mundane tasks. It means machines that still work fine have to be replaced when the software is updated, and the minimum specs are upped again. This is ultimately wasteful. It also means that bigger server parks are needed for a given workload. If you can make code more efficient, less hardware is needed, and less energy is wasted. Mobile computing (like embedded) can give an impetus to leaner programs, simply because cutting clock cycles can cut battery usage.
Re: And not a moment too soon!
As Niklaus Wirth says: Software is getting slower faster than hardware is getting faster.
Word 2.0 was a very capable word-processor, and ran happily on my 25 MHz 80386 machine with 4 MB of RAM (I really splashed out on that machine :-) ). Word 2010 would require rather more. More in fact than the processing power and memory of the good old Cray Y-MP. That is worrying.
GUIs of course do need more resources, but the above example suggests you can run a full-blown GUI-based word processor in 1,000 times less memory than we seem to need today. If you look at the memory footprint of something like FLTK, which is so small you can afford to link it statically for easier distribution, and compare that to some other tools, you cannot help but question the efficiency of some code.
Much of the best coding is going on in the embedded-systems world. You really have to conserve resources in that arena.
Re: So much for being a global company.
I must say I was a bit miffed at not being able to take part. I have several ideas of what to do on a petaflop machine, but as I am not a US or Canadian resident (excluding Quebec (mais pourqoui?)) I cannot send them in. AMD had similar rules for their "what would you do with 48 cores?" competition. There may be some law in the US requiring this, so nVidia may be obliged by law to include this rule. Pity.
Re: Right, so I will need even more RAM
"FFS - get yourself a high end graphics card! 256 cores + 1TB memory (or more) + proper parallel coding using CUDA. £300 will get you the dogs-danglies in the commercial world. If you want mil-aero specification - GE-IP have them for reasonable prices.
Image processing - visible, infra-red, microwave, radar, or all combined is exactly what CUDA on these high end graphics cards was designed for."
I assume you mean 1GB not 1TB of memory. If you can supply me a 1TB memory graphics card for £300, I am happy to give you a £300 tip :-). My images start at about 1GB, and end at 1.5 TB (for now). So they will not fit in my graphics cards (with the additional data needed during processing.
Regarding image processing and CUDA: For quite a few image processing problems you are right, in this case you are wrong. Connected filters that we use have a strictly data-driven processing order, which does not work well in CUDA. Indeed, because the outcome for every pixel depends on every other pixel (potentially), parallelization itself is hard (see the first method with can be found here (warning, pdf)). On 64 cores I am now getting about 30x speed-up. I am trying to adapt this to CUDA (or OpenCL) in collaboration with the CSIRO in Sydney, Australia, but we have not got it running yet.
Right, so I will need even more RAM
I am just testing a new compute server for processing remote sensing images (64 cores 512 GB of RAM). My first runs already use up to 480 GB of that, and chug through a detailed analysis of 3.5 Gigapixel image in just over two minutes (was nearly an hour). The new images will be 2.2x larger for the same area covered.
I WANT A TERABYTE of RAM!!!
These are not often mentioned, but they had quite a following. It was a neat machine, with Z80A and 128kB of memory expandable to 4MB, two asics controlling memory, sound and graphics. The memory worked at twice the clock frequency of the CPU, so the controller and CPU did not interfere (one had the even clock ticks, the other the ODD. Nice machine to play around with. Decent Basic, and word processor on board, very expandable. Linked it up to my Dad's daisy-wheel typewriter (what a racket that was
My guess: Windows ME
in which case you do not need to introduce a virus to have data and files going AWOL
Let the government handle it. That seems the most sure-fire way of messing things up.
Bringing back bespoke BACK FROM THE DEAD!!
Bespoke zombie processes?
Sorry couldn't resist
It suggests bucks can be passed arbitrarily.
Re: Interesting stuff.
A scan will be needed
Re: Some of these people should have done maths and not engineering
"Yes, but thats like saying "I've had a really clever idea - the sun is a large energy emitting source".
Its completely damned obvious.
The only people "making money" are those who actually aren't counting costs in the first place - ie someone writing something in their evenings or whilst sat at their desk being paid to do something else ;-)"
Agreed, it is obvious, but politicians need people to point out obvious things to them. Frequently.
And of course the pointing out the bleeding obvious must be done by qualified people like professors and engineers, or else the politicians might look silly.
Re: Some of these people should have done maths and not engineering
Was it not exactly the point of the professors and engineers that you have to sell a lot of apps just to break even?
Furthermore, what they appear to be saying is that you need a lot of investment, and that the idea of getting rich quickly from an app slapped together in a few weeks/days of coding is a pipe dream. That seems to make sense.
I do not think this will make a good mother's day gift
Tempting, very tempting
I have liked the format from the start. I will give this a serious look indeed.
So when they want to find interesting new asteroids
Do they just google for them?
Sorry, couldn't resist.
Mine is the one with "Turn Left at Orion" in the pocket
Might set these papers as study materials for our students.
Re: maybe i'm stupid
why do you think we have fast caches for chips? Imagine the entire memory working at the speed of the CPU. That would be awesome.
At the moment, I have to think hard about cache friendly processing orders. Getting it wrong can incur a 10-fold speed penalty, easily. If have a set of for-loops to traverse an image, having the x-coordinate loop outside the y-coordinate loop is tens times slower than the reverse, because of the way images are stored (row by row). A step in x moves to the next element in memory (= cache hit with standard read-ahead), whereas a step in y steps a whole row of data further, yielding a cache miss.
Such simple cases are easily sorted out, but some image processing has data-driven processing orders, very frequently requiring odd memory jumps. In these cases getting rid of latency is a godsend. Also, think of multi-core: ensuring cache coherence is a pain. Older Cray machine had no cache, and the memory worked at the speed of the CPU. This is much simpler and yields much better parallelization.
Re: and to think...
Clearly none of you have read the opening page of "Good Omens" by Pratchett and Gaiman properly!
Re: Can you imagine 70 years or so in a prison,
knowing you aren't getting out?
Good point. I sometimes wonder if even for the likes of Khadafi or Saddam Hussein, being put in prison for the long haul and being treated as if you were ordinary would not be the worst possible punishment for those types.