I doubt 60 GHz multipath is much different from 2.4GHz multipath conceptually. If they can build a 60 GHz front-end (and they can) they can build whatever processing they need.
Actually there is still neutrino production at Fermilab. The Tevatron main ring was shut down but the Main Injector is still operating for the NOvA project, a long-baseline neutrino experiment.
Space-age materials are pretty amazing, but Fusion-age materials are at a whole different level. I think the community hasn't expressed to the public just how daunting the challenges are. Controlling the plasma is one thing, but engineering the plasma-facing components (PFCs) is a whole 'nother kettle of fish.
The so-called "first wall" is the interior layer of the fusion reactor. It has to stand up to neutron bombardment, but it also has to avoid shedding particles into the plasma. For example high-Z materials such as tungsten, molybdenum, and vanadium are interesting for their neutron tolerance, but if atoms scrape off into the fusion plasma they will radiate like crazy (proportional to Z^2) and drain a lot of energy out of the plasma. That's why they are testing a Be coating (Z=4).
On the other hand, you have divertors, which sit in direct contact with the plasma and basically hold it in place so it doesn't randomly hit the wall. These have to withstand a high heat load. I admittedly don't know much about divertors so I will stop there.
There's also the superconducting material in the coils of the tokamak to consider. Of course there's a whole bunch of neutrons flying around. But also but it turns out that a lot of the issues with superconducting magnets are mechanical in nature. The HEP community has figured out how to build SC magnets consistently, but I think the magnets needed for a tokamak are quite different.
There is supposed to be a International Fusion Material Irradiation Facility, part of the ITER project (and basically a consolation prize to Japan), that will provide intense neutron beams for materials studies. But I am not really sure what the situation/timeline is for that given the funding problems ITER has faced.
Define practical; it doesn't get much simpler than a weight on a servo. In contrast, how much torque can you get from a small compact flywheel and how much is it going to cost? How quickly can you regeneratively brake it with decent energy recovery?
(You might be interested in this control-moment gyro controlled ballbot.)
I don't think usage is as consistent as WP would imply. In pieces with key signatures with lots of flats or sharps, you tend to get naturals without parentheses because it would be too cluttered to put them in.
I am a Berkeley EECS graduate, and I don't think you understand how it works. The department is a single entity, the EECS Department. However the University offers two different _majors_ that lead to a CS degree, in different Colleges. I don't know why they do this, but for example, you generally cannot double major if you're in the College of Engineering, but you can if you're in L&S. So it only has a bearing on your advising and degree requirements.
I took single class in fusion from a cheerfully cynical professor some years back, so please bear with me. It's my understanding that we don't have a good understanding of particle transport in tokamaks, i.e. "anomalous transport". Is this still true? What are the difficulties, and what approaches are people working on right now?
Relatedly, do we really understand H-mode and other enhanced confinement modes? What are the challenges in achieving the "advanced modes"?
Papers/citations would be great, if that's not too much trouble. Thanks for your time.
Andre Norton, the pen name of Alice Norton, wrote a whole bunch of sci-fi and fantasy books. I've only read the ones that are available for free on the Kindle store (so they're probably on Gutenberg) but I've been very impressed by the quality of the writing, considering the pulp-ish themes.
For example, there's a sequence of books, beginning with The Stars Are Ours!, that treats human colonization of space and contact with alien races. Another sequence, beginning with The Time Traders, considers time travel and advanced alien technology in a Cold War setting.
Broadcom keeps their datasheets so locked down that you have to sign an NDA to get anything, generally. This release comes as a bit of a surprise.
This is good news, but in retrospect, this seems backwards. If you want to grow an ecosystem, you need spec sheets. Did they choose Broadcom for the RPi design without any assurances that the datasheet would get opened up? Was this agreed upon from the beginning, and it's taken Broadcom this long to redact the datasheet? Or did Broadcom have a change of heart when they saw how popular the project became?
Uh, the magnetic fusion research budget has been falling from its peak in the 70s, at the height of the oil crisis. Take a look.
So why don't we have fusion? Because it's damned hard. We don't have the understanding and we don't have the materials. Every single fusion concept through history has turned out to have weaknesses, and most of them turn out to be fatal flaws from a power generation standpoint. The tokamak is our best bet, and that's after decades of research have turned up unstable regions of operation that have to be avoided.
If you knew the history of fusion, you'd be inclined to be skeptical about every new proposal. There are things about plasmas that we don't understand. Simulation is often intractable. Analysis from a physics standpoint is difficult and prone to wishful thinking. This is why people work on stuff that's been vetted, rather than risking their time on something that likely has a fatal flaw.
Migrating algorithms from C++ to FPGAs involves doing a Fourier Transform from time domain execution to spatial domain execution in order to maximize computational throughput.
What the hell is this supposed to mean? The document seems like the standard FPGA boilerplate otherwise, great for showing to management.
I don't know a whole lot about this but I'm on the mailing list for a department that was in the process of migrating to Calmail. (My email goes through a different system so it hasn't affected me.) After a slew of messages this past week about Calmail problems, they've decided to cancel the migration for now. Apparently Calmail is going to the cloud in the future, so they're hoping the existing servers last until then.
IANALE either, but I'm willing to believe it. Even if you have the netlist, the entities in the netlist are logic gates, or composite logic elements. Unless you go through the standard cell library and count gates, you don't know exactly how many transistors there are per entity. I'm also willing to believe that standard cells don't come with transistor counts, because at the chip level you're laying out rectangles of diffusion/metal/polysilicon and nobody cares about the exact number of transistors; plus the distinction gets fuzzy when you parallel devices to increase current handling.
The last one looks a lot like the 'crazing' pattern on some famous Chinese pottery. It's a motif that shows up on some recent buildings, e.g. UC Berkeley's East Asian Library. So I would guess the Chinese Army/DoD made their pattern like that for pride purposes.
Well, sure, but I have no idea why you would want to pay for that privilege. The Zynq is in a totally different weight class: dual 800MHz ARM9, DDR2/3 interface, gigabit tranceivers, 1Msps ADCs. All this hardware to replicate the functionality of a 20MHz 8-bit AVR? Why?
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I doubt 60 GHz multipath is much different from 2.4GHz multipath conceptually. If they can build a 60 GHz front-end (and they can) they can build whatever processing they need.
Actually there is still neutrino production at Fermilab. The Tevatron main ring was shut down but the Main Injector is still operating for the NOvA project, a long-baseline neutrino experiment.
http://www-nova.fnal.gov/how-nova-works.html
Space-age materials are pretty amazing, but Fusion-age materials are at a whole different level. I think the community hasn't expressed to the public just how daunting the challenges are. Controlling the plasma is one thing, but engineering the plasma-facing components (PFCs) is a whole 'nother kettle of fish.
The so-called "first wall" is the interior layer of the fusion reactor. It has to stand up to neutron bombardment, but it also has to avoid shedding particles into the plasma. For example high-Z materials such as tungsten, molybdenum, and vanadium are interesting for their neutron tolerance, but if atoms scrape off into the fusion plasma they will radiate like crazy (proportional to Z^2) and drain a lot of energy out of the plasma. That's why they are testing a Be coating (Z=4).
On the other hand, you have divertors, which sit in direct contact with the plasma and basically hold it in place so it doesn't randomly hit the wall. These have to withstand a high heat load. I admittedly don't know much about divertors so I will stop there.
There's also the superconducting material in the coils of the tokamak to consider. Of course there's a whole bunch of neutrons flying around. But also but it turns out that a lot of the issues with superconducting magnets are mechanical in nature. The HEP community has figured out how to build SC magnets consistently, but I think the magnets needed for a tokamak are quite different.
There is supposed to be a International Fusion Material Irradiation Facility, part of the ITER project (and basically a consolation prize to Japan), that will provide intense neutron beams for materials studies. But I am not really sure what the situation/timeline is for that given the funding problems ITER has faced.
Mod parent up, op-amp hype is rife in the audiophile community.
I've had trouble sourcing TORX/TOTX parts lately. Can't find them in stock anywhere.
Define practical; it doesn't get much simpler than a weight on a servo. In contrast, how much torque can you get from a small compact flywheel and how much is it going to cost? How quickly can you regeneratively brake it with decent energy recovery?
(You might be interested in this control-moment gyro controlled ballbot.)
I guess it's American usage. We don't ever say "burgled" over here; it sounds funny.
"dirty switching power supplies"
Wow, that really takes the cake. I wonder how they get from switching power to cancer... Actually, I don't want to know.
The book definitely has no shortage of movie-worthy scenes, but it's gonna take a really good director to string it all together.
I don't think usage is as consistent as WP would imply. In pieces with key signatures with lots of flats or sharps, you tend to get naturals without parentheses because it would be too cluttered to put them in.
I am a Berkeley EECS graduate, and I don't think you understand how it works. The department is a single entity, the EECS Department. However the University offers two different _majors_ that lead to a CS degree, in different Colleges. I don't know why they do this, but for example, you generally cannot double major if you're in the College of Engineering, but you can if you're in L&S. So it only has a bearing on your advising and degree requirements.
I took single class in fusion from a cheerfully cynical professor some years back, so please bear with me. It's my understanding that we don't have a good understanding of particle transport in tokamaks, i.e. "anomalous transport". Is this still true? What are the difficulties, and what approaches are people working on right now?
Relatedly, do we really understand H-mode and other enhanced confinement modes? What are the challenges in achieving the "advanced modes"?
Papers/citations would be great, if that's not too much trouble. Thanks for your time.
From my own highlight list:
How much of old material goes to make up the freshest novelty of human life.
--Nathaniel Hawthorne, House of the Seven Gables (1851)
Andre Norton, the pen name of Alice Norton, wrote a whole bunch of sci-fi and fantasy books. I've only read the ones that are available for free on the Kindle store (so they're probably on Gutenberg) but I've been very impressed by the quality of the writing, considering the pulp-ish themes.
For example, there's a sequence of books, beginning with The Stars Are Ours!, that treats human colonization of space and contact with alien races. Another sequence, beginning with The Time Traders, considers time travel and advanced alien technology in a Cold War setting.
Broadcom keeps their datasheets so locked down that you have to sign an NDA to get anything, generally. This release comes as a bit of a surprise.
This is good news, but in retrospect, this seems backwards. If you want to grow an ecosystem, you need spec sheets. Did they choose Broadcom for the RPi design without any assurances that the datasheet would get opened up? Was this agreed upon from the beginning, and it's taken Broadcom this long to redact the datasheet? Or did Broadcom have a change of heart when they saw how popular the project became?
Uh, the magnetic fusion research budget has been falling from its peak in the 70s, at the height of the oil crisis. Take a look.
So why don't we have fusion? Because it's damned hard. We don't have the understanding and we don't have the materials. Every single fusion concept through history has turned out to have weaknesses, and most of them turn out to be fatal flaws from a power generation standpoint. The tokamak is our best bet, and that's after decades of research have turned up unstable regions of operation that have to be avoided.
If you knew the history of fusion, you'd be inclined to be skeptical about every new proposal. There are things about plasmas that we don't understand. Simulation is often intractable. Analysis from a physics standpoint is difficult and prone to wishful thinking. This is why people work on stuff that's been vetted, rather than risking their time on something that likely has a fatal flaw.
Migrating algorithms from C++ to FPGAs involves doing a Fourier Transform from time domain
execution to spatial domain execution in order to maximize computational throughput.
What the hell is this supposed to mean? The document seems like the standard FPGA boilerplate otherwise, great for showing to management.
I don't know a whole lot about this but I'm on the mailing list for a department that was in the process of migrating to Calmail. (My email goes through a different system so it hasn't affected me.) After a slew of messages this past week about Calmail problems, they've decided to cancel the migration for now. Apparently Calmail is going to the cloud in the future, so they're hoping the existing servers last until then.
IANALE either, but I'm willing to believe it. Even if you have the netlist, the entities in the netlist are logic gates, or composite logic elements. Unless you go through the standard cell library and count gates, you don't know exactly how many transistors there are per entity. I'm also willing to believe that standard cells don't come with transistor counts, because at the chip level you're laying out rectangles of diffusion/metal/polysilicon and nobody cares about the exact number of transistors; plus the distinction gets fuzzy when you parallel devices to increase current handling.
Well, the things are ~$1200 for 10, so someone's making money, I bet.
The last one looks a lot like the 'crazing' pattern on some famous Chinese pottery. It's a motif that shows up on some recent buildings, e.g. UC Berkeley's East Asian Library. So I would guess the Chinese Army/DoD made their pattern like that for pride purposes.
You'll be able to pack more Aebleskiver into your mouth now.
I have weird friends.
I'd say you have great friends.
North of $10K sounds about right. Awesome but expensive.
Well, sure, but I have no idea why you would want to pay for that privilege. The Zynq is in a totally different weight class: dual 800MHz ARM9, DDR2/3 interface, gigabit tranceivers, 1Msps ADCs. All this hardware to replicate the functionality of a 20MHz 8-bit AVR? Why?
An AVR core for FPGA already exists.