It sounds close to the FHSS technique but applied to the Internet. FHSS is often used in military applications to avoid jamming and interceptions. Here, instead of switching carriers, one has to switch ports.
The real interest of column-based storage is that each column only carries a given data type. This means that allocation can be optimal (up to the bit level). Moreover, memory-mapping a column gives a contiguous array of uniform data, which is randomly accessible. Scanning a column consumes much less memory than for row-based tables, since only the relevant data has to be present in memory. Here is a great intro to its view model.
Another big advantage of Metakit (and probably other column-based DBMSs) is that it supports hierarchical tables (dubbed subviews). A column type can thus be a table itself. This means that rows can contain variable data, which eliminates most of the needs for table joins and relational algebra. Moreover the table definitions can be self-referential: one can easily represent tree data in a single table, such as an XML document or a file hierarchy. For example, the following table definition is sufficient to store a whole tree of ints: tree[value:I,children[^]] where ^ references the table itself.
I've used Metakit with success in several commercial projects. The learning curve is a bit steep, mostly because of the sometimes obscure documentation, the radical choices, and terminology which often depart from that used in traditional RDBMS. I had to experiment a bit to make the right choices. However, once in hand, it is lightning fast. I was able to design an object-based system where all data were stored in memory-mapped storage, and were accessed in a fully transactional manner. This means that in-memory objects were only wrappers around memory-mapped Metakit storage: setting an object property actually altered the data in the right column inside the storage.
Given the current state of science, one cannot tell in the case of a GM organism whether deleted generic code had a function even though it appears as "junk", or whether the newly added code hasn't unpredictable side effects because it interferes with other "junk" or "active" code. I think everybody can see the analogy with computers, ie data versus code. In many architectures both can be deeply intertwined and are sometimes indistinguishable from each other (e.g LISP, Tcl). It's like blindly hand-patching running executables, or buffer overflow exploits.
We all know Microsoft's tacticts to go after anyone that dare to use "Windows" in its title. With that in mind, Philippe Gildas (who is BTW a very highly regarded presenter in France and not some Joe Shmo who wants to make a quick buck) might have decided to strike first. You can be sure that Microsoft would have sued him, had he launched his TV station. Oh, and Gildas DID register Vista for software use.
Agreed, but while Reed Solomon is well suited for small scratches on a CD or small losses of streamed data, it is rather inefficient in case of massive losses that can destroy a whole (contiguous) block of the data, as it operates on small blocks, and so its range of effect is limited. Fortunately there exist very robust FEC codes that can protect larger blocks. With Raptor or LDPC codes, one can protect very large blocks of data with redundant codes that yield a high probability of recovery given an overall loss rate.
In the case of critical data storage, I'd advocate in favor of large block codes such as Raptor or LDPC with a redundancy of at least 100% (meaning that one can recover the whole data is half of it is destroyed). Note that this need not be done on the physical layer, rather one could FEC-encode files with varying levels of redundancy.
Note that data recovery on damaged physical storage is no different than on unreliable transmission channels such as Wifi, 3G or IP multicast. For information, Raptor codes have been chosen for the DVB-H standard as the preferred FEC scheme for IP datacasting (based on the FLUTE protocol), and LDPC is used in DVB-S2.
For those interested by LDPC, there exists an excellent LGPL'd library by the french INRIA here (info) and here (download), and best of all it's a patent-free technology. As for Raptor, it is unfortunately proprietary and patented by Digital Fountain, but you can however find a lot of enlightening info on their Web site (worth a read if you're interested in FEC technologies).
Ulf Bossel, the author of the study, is a fuel cell expert. The study specifically discards pure hydrogen versus electricity as an energy carrier. However he advocates the use of biomass-based fuel cells like methanol:
Ulf Bossel: So, who wants to buy a hydrogen vehicle? Today, the plug-in hybrid is the proper development goal. We will have plug-in hybrids in the sustainable energy world because 80% of the driving is done for rides of less than 50 kilometers, or 50 miles. 80% of the miles are driven in short-range commuting traffic. Such short rides can all be handled with electric cars. So, a plug-in hybrid means you fill up the batteries at home, you fill them up again at work and you commute between work and home with electricity. When you take your car on longer rides or go on vacation you may fill up the tank with gasoline as long as it lasts, but with methanol or some fuel derived from biomass in the sustainable future. This is the most likely picture of the future.
Ben Kenney: I totally agree that hydrogen is much less efficient than batteries. Just from quick back of the envelope calculations, if somebody drove a hydrogen-fuelled cell car, say 35 kilometers everyday, then the amount of extra electricity that you have to use to make that hydrogen is pretty much the same amount of electricity as the per capita electricity consumption in Germany.
So it seems that these guys know what they are talking about: the global efficiency of pure hydrogen is lower that alternatives, such as the electric grid.
FYI he uses a Hilbert curve to map the IPv4 space on a square. This is simply brilliant, elegant and beautiful, clearly the best map of the Net I've seen in years. I love how the range of Multicast IPs renders as a square.
"Scientists introduce a predator that eats lizards with long legs, and find the average leg length of the surviving lizards to be shorter!"
The predators ate lizards they caught regardless of their leg length. HOWEVER, those with shorter legs had an advantage for survival, and this physical character eventually became dominant IN ONE GENERATION: the whole species evolved. If this wasn't the case you'll find that the introduction of a new predator would have no effect on the birth occurrence of long vs short-legged individuals.
... in a slightly (and IMHO better) way. Try the following: go to https://logitelnet.socgen.com/, then enter a bogus 8-digit client number like 12345678 in the upper left entry (below "Code client"), and validate. The system then asks for your PIN using a random keypad. Not only does the position of the keys change, but also the position of the keypad on the page. Of course it doesn't defeat screen grabbing but it's enough for mouse/key loggers.
"With fossils unearthed recently showing _tropical_ weather in Northern Canada, I think it's safe to say that the Arctic ice cap is a temporary feature."
That's because what we call Canada nowadays was located a in tropical area. Ever heard of continental drift? The Arctic ice cap is quite permanent compared to humanity. This becomes more evident every day thanks to our stupidity.
how do we know whether it has moving parts in it or not?
RTFA:
LBO has developed unique laser-based projection technology, which uses computational algorithms and novel optical techniques to allow miniature lasers to display video images in real-time using the diffractive nature of laser light. This overcomes the size limitation of conventional projection techniques, allowing projectors to be smaller than ever before. Understand that there is no glass, no prisms, NO MOVING PARTS, and no need for fans to provide heat dissipation. In addition, it runs on less than 1.5W at full power and less than 350mW while displaying typical video images (50% average pixel amplitude. There is also an infinite focus, meaning that no matter how close or far away, there are no optics to adjust for a clear picture.
Remember how a laser light diffract when passing through a pinhole? Infos here and here (in french). FYI, the latter university is named after the 19h century french scientist who gave his name to the Fourier transform we all know.
I guess by superimposing many diffraction patterns they are able to generate the picture. This should imply Fourier-like transforms of the source image.
Fraunhofer's use micromirrors. LBO's use no moving parts but "computational algorithms and novel optical techniques to allow miniature lasers to display video images in real-time using the diffractive nature of laser light".
Read this very enlightening article on Project Censored. It mentions facts about paper trails and exit polls. The more I learn about the 2004 presidential election, the more I think it's been stolen even more than in 2000. Even a sincere Republican should have serious doubts about its legitimity.
Slashdot Mirror
Why Threads Are A Bad Idea (for most purposes) http://home.pacbell.net/ouster/threads.pdf
It sounds close to the FHSS technique but applied to the Internet. FHSS is often used in military applications to avoid jamming and interceptions. Here, instead of switching carriers, one has to switch ports.
Note to myself: remember to expand all comments before posting.
http://xkcd.com/323/
... and best of all, it's Open Source and free!
Official page
Wikipedia info
The real interest of column-based storage is that each column only carries a given data type. This means that allocation can be optimal (up to the bit level). Moreover, memory-mapping a column gives a contiguous array of uniform data, which is randomly accessible. Scanning a column consumes much less memory than for row-based tables, since only the relevant data has to be present in memory. Here is a great intro to its view model.
Another big advantage of Metakit (and probably other column-based DBMSs) is that it supports hierarchical tables (dubbed subviews). A column type can thus be a table itself. This means that rows can contain variable data, which eliminates most of the needs for table joins and relational algebra. Moreover the table definitions can be self-referential: one can easily represent tree data in a single table, such as an XML document or a file hierarchy. For example, the following table definition is sufficient to store a whole tree of ints: tree[value:I,children[^]] where ^ references the table itself.
I've used Metakit with success in several commercial projects. The learning curve is a bit steep, mostly because of the sometimes obscure documentation, the radical choices, and terminology which often depart from that used in traditional RDBMS. I had to experiment a bit to make the right choices. However, once in hand, it is lightning fast. I was able to design an object-based system where all data were stored in memory-mapped storage, and were accessed in a fully transactional manner. This means that in-memory objects were only wrappers around memory-mapped Metakit storage: setting an object property actually altered the data in the right column inside the storage.
Given the current state of science, one cannot tell in the case of a GM organism whether deleted generic code had a function even though it appears as "junk", or whether the newly added code hasn't unpredictable side effects because it interferes with other "junk" or "active" code. I think everybody can see the analogy with computers, ie data versus code. In many architectures both can be deeply intertwined and are sometimes indistinguishable from each other (e.g LISP, Tcl). It's like blindly hand-patching running executables, or buffer overflow exploits.
We all know Microsoft's tacticts to go after anyone that dare to use "Windows" in its title. With that in mind, Philippe Gildas (who is BTW a very highly regarded presenter in France and not some Joe Shmo who wants to make a quick buck) might have decided to strike first. You can be sure that Microsoft would have sued him, had he launched his TV station. Oh, and Gildas DID register Vista for software use.
Read this page to know why charcoal is not only better than paper, but actually a viable way to solve CO2 emission problems:
l ity-energy-independence-and.html
http://ergosphere.blogspot.com/2006/11/sustainabi
Seriously, would the UK bend over like this if the People's Republic of China or Singapore asked them to? Maybe it's really the 51th state after all.
Agreed, but while Reed Solomon is well suited for small scratches on a CD or small losses of streamed data, it is rather inefficient in case of massive losses that can destroy a whole (contiguous) block of the data, as it operates on small blocks, and so its range of effect is limited. Fortunately there exist very robust FEC codes that can protect larger blocks. With Raptor or LDPC codes, one can protect very large blocks of data with redundant codes that yield a high probability of recovery given an overall loss rate.
In the case of critical data storage, I'd advocate in favor of large block codes such as Raptor or LDPC with a redundancy of at least 100% (meaning that one can recover the whole data is half of it is destroyed). Note that this need not be done on the physical layer, rather one could FEC-encode files with varying levels of redundancy.
Note that data recovery on damaged physical storage is no different than on unreliable transmission channels such as Wifi, 3G or IP multicast. For information, Raptor codes have been chosen for the DVB-H standard as the preferred FEC scheme for IP datacasting (based on the FLUTE protocol), and LDPC is used in DVB-S2.
For those interested by LDPC, there exists an excellent LGPL'd library by the french INRIA here (info) and here (download), and best of all it's a patent-free technology. As for Raptor, it is unfortunately proprietary and patented by Digital Fountain, but you can however find a lot of enlightening info on their Web site (worth a read if you're interested in FEC technologies).
http://en.wikipedia.org/wiki/The_Marching_Morons
Ben Kenney: I totally agree that hydrogen is much less efficient than batteries. Just from quick back of the envelope calculations, if somebody drove a hydrogen-fuelled cell car, say 35 kilometers everyday, then the amount of extra electricity that you have to use to make that hydrogen is pretty much the same amount of electricity as the per capita electricity consumption in Germany.
So it seems that these guys know what they are talking about: the global efficiency of pure hydrogen is lower that alternatives, such as the electric grid.
FYI he uses a Hilbert curve to map the IPv4 space on a square. This is simply brilliant, elegant and beautiful, clearly the best map of the Net I've seen in years. I love how the range of Multicast IPs renders as a square.
http://en.wikipedia.org/wiki/Hilbert_curve
"Scientists introduce a predator that eats lizards with long legs, and find the average leg length of the surviving lizards to be shorter!"
The predators ate lizards they caught regardless of their leg length. HOWEVER, those with shorter legs had an advantage for survival, and this physical character eventually became dominant IN ONE GENERATION: the whole species evolved. If this wasn't the case you'll find that the introduction of a new predator would have no effect on the birth occurrence of long vs short-legged individuals.
... in a slightly (and IMHO better) way. Try the following: go to https://logitelnet.socgen.com/, then enter a bogus 8-digit client number like 12345678 in the upper left entry (below "Code client"), and validate. The system then asks for your PIN using a random keypad. Not only does the position of the keys change, but also the position of the keypad on the page. Of course it doesn't defeat screen grabbing but it's enough for mouse/key loggers.
You mispel enstrumans.
"With fossils unearthed recently showing _tropical_ weather in Northern Canada, I think it's safe to say that the Arctic ice cap is a temporary feature."
That's because what we call Canada nowadays was located a in tropical area. Ever heard of continental drift? The Arctic ice cap is quite permanent compared to humanity. This becomes more evident every day thanks to our stupidity.
'nuff said
Kiss Technology make kick-ass DVD/DivX players and PVRs. They also were the first brand to sell a DVD player that could read MP3s.
how do we know whether it has moving parts in it or not?
RTFA:
LBO has developed unique laser-based projection technology, which uses computational algorithms and novel optical techniques to allow miniature lasers to display video images in real-time using the diffractive nature of laser light. This overcomes the size limitation of conventional projection techniques, allowing projectors to be smaller than ever before. Understand that there is no glass, no prisms, NO MOVING PARTS, and no need for fans to provide heat dissipation. In addition, it runs on less than 1.5W at full power and less than 350mW while displaying typical video images (50% average pixel amplitude. There is also an infinite focus, meaning that no matter how close or far away, there are no optics to adjust for a clear picture.Remember how a laser light diffract when passing through a pinhole? Infos here and here (in french). FYI, the latter university is named after the 19h century french scientist who gave his name to the Fourier transform we all know.
I guess by superimposing many diffraction patterns they are able to generate the picture. This should imply Fourier-like transforms of the source image.
Fraunhofer's use micromirrors. LBO's use no moving parts but "computational algorithms and novel optical techniques to allow miniature lasers to display video images in real-time using the diffractive nature of laser light".
Liquid War is another very entertaining and yet very simple multiplayer game.
Such a slaughter does not serve science, and hardly deserves being called science. No matter how 'small' the group might be.
"Science sans conscience n'est que ruine de l'âme" -- Rabelais
(Science without conscience is only ruin of the heart)
Just pass a law to restrict ET sites to certain TCP/IP ports, then all we have to do is firewall them. Problem solved, thank you Mr. Yarro!
Read this very enlightening article on Project Censored. It mentions facts about paper trails and exit polls. The more I learn about the 2004 presidential election, the more I think it's been stolen even more than in 2000. Even a sincere Republican should have serious doubts about its legitimity.