My guess is that most of those new users from developing nations hardly have the potential to generate profit remotely in proportion to their consumed bandwidth.
I think this is bad economic thinking. First, the deployment of bandwidth in developing countries for equivalent technologies will be cheaper because of the lower costs of living.
Secondly, there are a wide range of last-mile options available now that were not widely available as the web ramped-up in the US (such as wireless). Technology has also advanced to make the price of very hefty routers much less than the sunk costs in the US.
Third, I don't expect that the "average" Internet user in India will spend all day downloading MP3s. They will probably be on a lower-bandwidth connection, and sharing a computer among an entire village. These computers will be used much more for business and learning operations, and much less for bandwidth-hogging entertainment.
The world's poor represent an incredible market. The concept of having another two billion people plugged into (an equivalent of) eBay is immense. Market information about farmining commodity prices, and increased access to information about advanced farming technology will make farmers more profitable.
The Spaceway satellites have 48 spot beams of 125 MHz, to deliver at least 100 Mbps per spot beam, possibly more dependign on modulation scheme and FEC. The spot beams are created from a 1500 element phased array.
I can assure you there is still rain that Ka won't go through, even with spot beams and power ramps, but I don't think it will be any worse than existing Ku-band DBS reception.
70% of people watch on cable anyway - will your LP station get an HD slot with your MSO?
While ATSC standards seems like something written in stone, keep in mind that ATSC just approved Enhanced VSB which is a variant bitstream than can be added to your existing DTV signal to provide a channel that is easier to receive.
No doubt if H.264/WMT comes along in a serious way, ATSC will buy into it, and the CEA will lobby the FCC to make the change so they can sell lots of new set-top-boxes.
I've done native MPEG-2 editing from the JVC HDV camera using Edius. It is better to use an MPEG-2 aware editor on HDV footage to avoid uneeded recompression.
Half of broadcasters went one way, half went the other. Keep in mind the existing business relationships at networks and stations.
But 1080i really does seem to provide a higher-resolution experience (when watched on a real 1080 monitor...) HDNET went 1080i, and most PBS content is 1080i. But I will admit it is really a religious issue.
I've never heard about the duopoly issue with DTV channel assignments. It is my impression that every analog broadcast channel is entitled to a DTV channel as well during the transition. Do you have a reference on this?
I can assure you that MPEG-2 is the ONLY codec that is broadcast-ready. Certainly when ATSC specs were defined, they weren't even thoughts.
I've seen the best H.264 and Windows Media live encoders on the planet, and they can barely get the same quality at the same bitrate as the best mid-level MPEG-2 live encoders.
Keep in mind that MPEG-2 encoders have had years to get better. People keep coming up with ways to cut bits, you now have live 2-pass encoders, pre-filtering, etc. MPEG-2 live encoding quality has improved 100% in the last five years in terms of equivalent bitrate quality.
I expect 2-3 years before the live H.264/WMT encoders can catch up with live MPEG-2 encoders.
I've shot with the JVC HDV camera, and my impression of it is that the resolution is excellent (as is to be expected), but the real quality differentiator between it and a "real HD" camera is the quality of color and image delivered by the whole system, not just a high resolution imaging chip.
This is not suprising - I have always found the image and color quality of DV cameras to be much lower than even medium-end pro cameras (such as the elderly SVHS Panasonic Supercam). The prosumer cameras do not have $3,000 lenses. They do not have the amazing amount of color DSP going on as the pro cameras.
But at the same time, HDV cameras are better than nothing, and certainly good for "riskier" shots where a $100,000 HDCAM camera being lost would be a problem. You just can't skydive with a full-size camera, for instance...
One other issue is that 25 Mbps is really limiting for MPEG-2 HD (heh, so is 19.4 Mbps, but that is another topic).
If you are into a lot of action with lots of uncorrelated motion vectors, you might be better off with upconverted DV, as 25 Mbps is fine for inraframe coded DV.
During the development of the Space Shuttle, the choice was between building a new facility on the Gulf coast which could launch into any orbit (including polar), or to retrofit existing operations at KSC and Vandenburg AFB in California.
Of course, the Gulf coast gets hit with plenty of hurricanes as well.
A launch was planned for Vandenburg AFB, but after the first Shuttle accident, all operations were consolidated to KSC. Since Shuttle would no longer be hoisting spacecraft with significant propellant, the DoD had no more interest in polar Shuttle orbits.
Re:Breed Plutonium? Steam?
on
Port-A-Nuke
·
· Score: 1
The amount of Pu-240 depends on the burnup rate.
I still want to know how it is "tamper proof" to avoid people running it in weapons-grade breeding operation.
That said, I have no problems with the US operating helium gas turbine reactors within the borders of the US...
Re:Steam? Well...
on
Port-A-Nuke
·
· Score: 2, Informative
JAERI is developing the Gas Turbine High Temperature Reactor (GTHTR) of up to 600 MW thermal per module. It uses improved HTTR fuel elements with 14% enriched uranium achieving high burn-up (112 GWd/t). Helium at 850C drives a horizontal turbine at 47% efficiency to produce up to 300 MWe. The core consists of 90 hexagonal fuel columns 8 metres high arranged in a ring, with reflectors. Each column consists of eight one-metre high elements 0.4 m across and holding 57 fuel pins made up of fuel particles with 0.55 mm diameter kernels and 0.14 mm buffer layer. In each 2-yearly refuelling, alternate layers of elements are replaced so that each remains for 4 years.
A US design, the Gas Turbine - Modular Helium Reactor (GT-MHR), will be built as modules of 285 MWe each directly driving a gas turbine at 48% thermal efficiency. The cylindrical core consists of 102 hexagonal fuel element columns of graphite blocks with channels for helium and control rods. Graphite reflector blocks are both inside and around the core. Half the core is replaced every 18 months. Burn-up is about 100 GWd/t, and coolant outlet temperature is 850C with a target of 1000C. It is being developed by General Atomics in partnership with Russia's Minatom, supported by Fuji (Japan). Initially it will be used to burn pure ex-weapons plutonium at Tomsk in Russia.
A smaller version of this, the Remote-Site Modular Helium Reactor (RS-MHR) of 10-25 MWe has been proposed by General Atomics. The fuel would be 20% enriched and refuelling interval would be 6-8 years.
A third full-size HTR design is Areva's Very High Temperature Reactor (VHTR) being put forward by Framatome ANP. It is based on the GT-MHR and has also involved Fuji. Reference design is 600 MW (thermal) with prismatic block fuel like the GT-MHR. Target core outlet temperature is 1000C and it uses and indirect cycle, possibly with a helium-nitrogen mix in the secondary system. This removes the possibility of contaminating the generation or hydrogen production plant with radionuclides from the reactor core.
HTRs can potentially use thorium-based fuels, such as HEU with Th, U-233 with Th, and Pu with Th. Most of the experience with thorium fuels has been in HTRs.
Quantum teleportation propulsion faces a problem - the energy required to provide a way to entangle the particles would be huge and increase over distance. You are just as well off using an earth-bound laser to propel a light sail.
Breed Plutonium? Steam?
on
Port-A-Nuke
·
· Score: 4, Interesting
Personally, I still think the helium-cooled pebble bed reactors would be better for long-term operation.
I can't believe that anything having to do with steam will survive 30 years without maintenance. Corrosion happens when you have water. High-pressure helium (or other unreactive noble gas) is a safer cooling solution.
Also this whole breeding plutonium thing is real proliferation risk. The article says the reactor is "tamper resistant," but I don't see why someone couldn't bore through the side of the thing and take out the fuel rods. I think a non-breeding solution would be safer.
The biggest issue with the "pebble bed" concept is the physical removal and addition of the pebbles, which is requires too many moving parts to be sealed.
Certainly you could work out some sealed solution to a long-term pebble bed only having a part of the core fissioning at any point, using some sort of neutron absorbing rods or liquid.
I doubt what is going on is nuclear fusion, but we certainly should be studying and understanding metal/hydrogen interactions, as they appear to be very complex, and could have a wide variety of chemical uses (such as dense hydrogen storage, for instance).
Reprocessing is not economic right now, compared to the cheap cost of uranium. But maybe uranium might not stay so cheap if China is ramping up nuclear reactors...
However don't worry, there are systems (partical accelerator breeding) that can breed nuclear fuel from Thorium, which is incredibly abundant, even if we ever "run out" of natural U3O8.
The Florida coast allows KSC to launch into 39 to 57 degree orbital inclinations.
The one thing Florida can't do is polar and retrograde orbits. Those are launched from Vandenburg AFB on the California coast.
Originally, a single Gulf Coast area near Matagorda, Texas, was being considered to be the Shuttle launch facility, which would provide downrange safety for all types of orbit insertions, but the decision was made to go with a dual east/west coast model with existing KSC and Vandenburg sites.
After the Challenger disaster, a decision was made to end any Shuttle operations from Vandenburg.
Given the US GDP and its expected growth, the current Federal debt load is certainly manageable. But you are correct that yearly deficits need to be reduced to keep the debt load manageable. Deficits were ended, briefly, during the last period of significant growth.
What I am really unsure about is whether these "10 Mbps connections" really provide 10 Mbps Internet connectivity. I am sittign on top of multiple OC3s, and the best actual Internet speeds I get is around 7 Mbps.
Manufacturing in the US did not start declining until 1975 or so. Service sector jobs may have been increasing too, but the bad news started in the mid 70s.
Please don't be ignorant. In 1950, manufacturing jobs were 30% of the US workforce. By 1975, it was 23%. Now it is 11%.
During that time, manufacturing has consistantly been around 15-20% of US GDP, due to increasing working productivity.
Slashdot Mirror
"I'm here to PIMP your SPACESHIP!"
My guess is that most of those new users from developing nations hardly have the potential to generate profit remotely in proportion to their consumed bandwidth.
I think this is bad economic thinking. First, the deployment of bandwidth in developing countries for equivalent technologies will be cheaper because of the lower costs of living.
Secondly, there are a wide range of last-mile options available now that were not widely available as the web ramped-up in the US (such as wireless). Technology has also advanced to make the price of very hefty routers much less than the sunk costs in the US.
Third, I don't expect that the "average" Internet user in India will spend all day downloading MP3s. They will probably be on a lower-bandwidth connection, and sharing a computer among an entire village. These computers will be used much more for business and learning operations, and much less for bandwidth-hogging entertainment.
The world's poor represent an incredible market. The concept of having another two billion people plugged into (an equivalent of) eBay is immense. Market information about farmining commodity prices, and increased access to information about advanced farming technology will make farmers more profitable.
The Spaceway satellites have 48 spot beams of 125 MHz, to deliver at least 100 Mbps per spot beam, possibly more dependign on modulation scheme and FEC. The spot beams are created from a 1500 element phased array.
Are you kidding? 19.34 Mbps ATSC HD is horrible. I prefer HD at speeds of at least 50 Mbps...but you take what you can get.
If your dish isn't pointed at their satellite, you won't get interference...
I can assure you there is still rain that Ka won't go through, even with spot beams and power ramps, but I don't think it will be any worse than existing Ku-band DBS reception.
Guido van Rossum for Python
Jim Fulton for Zope.
Wow, sorry about your DTV allocation!
70% of people watch on cable anyway - will your LP station get an HD slot with your MSO?
While ATSC standards seems like something written in stone, keep in mind that ATSC just approved Enhanced VSB which is a variant bitstream than can be added to your existing DTV signal to provide a channel that is easier to receive.
No doubt if H.264/WMT comes along in a serious way, ATSC will buy into it, and the CEA will lobby the FCC to make the change so they can sell lots of new set-top-boxes.
Yes, it is more an issue of early HDCAM not doing 720p. I believe you can get a 720p option now, plus the move is to the "HDCAM SR" format.
I've done native MPEG-2 editing from the JVC HDV camera using Edius. It is better to use an MPEG-2 aware editor on HDV footage to avoid uneeded recompression.
Here is the real reason for the 1080i/720p split:
Sony HDCAM: 1080i
Panasonic D5: 720p
Half of broadcasters went one way, half went the other. Keep in mind the existing business relationships at networks and stations.
But 1080i really does seem to provide a higher-resolution experience (when watched on a real 1080 monitor...) HDNET went 1080i, and most PBS content is 1080i. But I will admit it is really a religious issue.
I've never heard about the duopoly issue with DTV channel assignments. It is my impression that every analog broadcast channel is entitled to a DTV channel as well during the transition. Do you have a reference on this?
I can assure you that MPEG-2 is the ONLY codec that is broadcast-ready. Certainly when ATSC specs were defined, they weren't even thoughts.
I've seen the best H.264 and Windows Media live encoders on the planet, and they can barely get the same quality at the same bitrate as the best mid-level MPEG-2 live encoders.
Keep in mind that MPEG-2 encoders have had years to get better. People keep coming up with ways to cut bits, you now have live 2-pass encoders, pre-filtering, etc. MPEG-2 live encoding quality has improved 100% in the last five years in terms of equivalent bitrate quality.
I expect 2-3 years before the live H.264/WMT encoders can catch up with live MPEG-2 encoders.
I've shot with the JVC HDV camera, and my impression of it is that the resolution is excellent (as is to be expected), but the real quality differentiator between it and a "real HD" camera is the quality of color and image delivered by the whole system, not just a high resolution imaging chip.
This is not suprising - I have always found the image and color quality of DV cameras to be much lower than even medium-end pro cameras (such as the elderly SVHS Panasonic Supercam). The prosumer cameras do not have $3,000 lenses. They do not have the amazing amount of color DSP going on as the pro cameras.
But at the same time, HDV cameras are better than nothing, and certainly good for "riskier" shots where a $100,000 HDCAM camera being lost would be a problem. You just can't skydive with a full-size camera, for instance...
One other issue is that 25 Mbps is really limiting for MPEG-2 HD (heh, so is 19.4 Mbps, but that is another topic).
If you are into a lot of action with lots of uncorrelated motion vectors, you might be better off with upconverted DV, as 25 Mbps is fine for inraframe coded DV.
During the development of the Space Shuttle, the choice was between building a new facility on the Gulf coast which could launch into any orbit (including polar), or to retrofit existing operations at KSC and Vandenburg AFB in California.
Of course, the Gulf coast gets hit with plenty of hurricanes as well.
A launch was planned for Vandenburg AFB, but after the first Shuttle accident, all operations were consolidated to KSC. Since Shuttle would no longer be hoisting spacecraft with significant propellant, the DoD had no more interest in polar Shuttle orbits.
The amount of Pu-240 depends on the burnup rate.
I still want to know how it is "tamper proof" to avoid people running it in weapons-grade breeding operation.
That said, I have no problems with the US operating helium gas turbine reactors within the borders of the US...
pretty hard to generate electricity without steam
Nope, high pressure gas turbines work fine:
JAERI is developing the Gas Turbine High Temperature Reactor (GTHTR) of up to 600 MW thermal per module. It uses improved HTTR fuel elements with 14% enriched uranium achieving high burn-up (112 GWd/t). Helium at 850C drives a horizontal turbine at 47% efficiency to produce up to 300 MWe. The core consists of 90 hexagonal fuel columns 8 metres high arranged in a ring, with reflectors. Each column consists of eight one-metre high elements 0.4 m across and holding 57 fuel pins made up of fuel particles with 0.55 mm diameter kernels and 0.14 mm buffer layer. In each 2-yearly refuelling, alternate layers of elements are replaced so that each remains for 4 years.
A US design, the Gas Turbine - Modular Helium Reactor (GT-MHR), will be built as modules of 285 MWe each directly driving a gas turbine at 48% thermal efficiency. The cylindrical core consists of 102 hexagonal fuel element columns of graphite blocks with channels for helium and control rods. Graphite reflector blocks are both inside and around the core. Half the core is replaced every 18 months. Burn-up is about 100 GWd/t, and coolant outlet temperature is 850C with a target of 1000C. It is being developed by General Atomics in partnership with Russia's Minatom, supported by Fuji (Japan). Initially it will be used to burn pure ex-weapons plutonium at Tomsk in Russia.
A smaller version of this, the Remote-Site Modular Helium Reactor (RS-MHR) of 10-25 MWe has been proposed by General Atomics. The fuel would be 20% enriched and refuelling interval would be 6-8 years.
A third full-size HTR design is Areva's Very High Temperature Reactor (VHTR) being put forward by Framatome ANP. It is based on the GT-MHR and has also involved Fuji. Reference design is 600 MW (thermal) with prismatic block fuel like the GT-MHR. Target core outlet temperature is 1000C and it uses and indirect cycle, possibly with a helium-nitrogen mix in the secondary system. This removes the possibility of contaminating the generation or hydrogen production plant with radionuclides from the reactor core.
HTRs can potentially use thorium-based fuels, such as HEU with Th, U-233 with Th, and Pu with Th. Most of the experience with thorium fuels has been in HTRs.
Quantum teleportation propulsion faces a problem - the energy required to provide a way to entangle the particles would be huge and increase over distance. You are just as well off using an earth-bound laser to propel a light sail.
Personally, I still think the helium-cooled pebble bed reactors would be better for long-term operation.
I can't believe that anything having to do with steam will survive 30 years without maintenance. Corrosion happens when you have water. High-pressure helium (or other unreactive noble gas) is a safer cooling solution.
Also this whole breeding plutonium thing is real proliferation risk. The article says the reactor is "tamper resistant," but I don't see why someone couldn't bore through the side of the thing and take out the fuel rods. I think a non-breeding solution would be safer.
The biggest issue with the "pebble bed" concept is the physical removal and addition of the pebbles, which is requires too many moving parts to be sealed.
Certainly you could work out some sealed solution to a long-term pebble bed only having a part of the core fissioning at any point, using some sort of neutron absorbing rods or liquid.
Where I work we are dumping Ingres for Microsoft SQL Server...it is really an issue of standardization and ease of development.
I doubt what is going on is nuclear fusion, but we certainly should be studying and understanding metal/hydrogen interactions, as they appear to be very complex, and could have a wide variety of chemical uses (such as dense hydrogen storage, for instance).
Reprocessing is not economic right now, compared to the cheap cost of uranium. But maybe uranium might not stay so cheap if China is ramping up nuclear reactors...
However don't worry, there are systems (partical accelerator breeding) that can breed nuclear fuel from Thorium, which is incredibly abundant, even if we ever "run out" of natural U3O8.
An inflatable re-entry craft is nothing compared to Airship-to-Orbit.
The Florida coast allows KSC to launch into 39 to 57 degree orbital inclinations.
The one thing Florida can't do is polar and retrograde orbits. Those are launched from Vandenburg AFB on the California coast.
Originally, a single Gulf Coast area near Matagorda, Texas, was being considered to be the Shuttle launch facility, which would provide downrange safety for all types of orbit insertions, but the decision was made to go with a dual east/west coast model with existing KSC and Vandenburg sites.
After the Challenger disaster, a decision was made to end any Shuttle operations from Vandenburg.
Given the US GDP and its expected growth, the current Federal debt load is certainly manageable. But you are correct that yearly deficits need to be reduced to keep the debt load manageable. Deficits were ended, briefly, during the last period of significant growth.
What I am really unsure about is whether these "10 Mbps connections" really provide 10 Mbps Internet connectivity. I am sittign on top of multiple OC3s, and the best actual Internet speeds I get is around 7 Mbps.
Manufacturing in the US did not start declining until 1975 or so. Service sector jobs may have been increasing too, but the bad news started in the mid 70s.
Please don't be ignorant. In 1950, manufacturing jobs were 30% of the US workforce. By 1975, it was 23%. Now it is 11%.
During that time, manufacturing has consistantly been around 15-20% of US GDP, due to increasing working productivity.