No, the purpose of "current limiting" is to get more control over the system peak loads, since the utilites (for a variety of good reasons, including environmental and regulatory concerns, and a variety of poor reasons, notably NIMBY problems) have been unable to increase generating and transmission capacity as fast as peak loads have been increasing.
Actually power companies are actually banking on Electric Vehicles with their massive battery packs of storage as being integral portions of the electrical grid so that they will finally be able to store large amounts of electricity.
Very true. This is not a panacea, however, as utilities' peak load is typically around 5 PM (1700) local time, when most cars are not attached to the grid, and most drivers typically would plug in their vehicles in the evening, a high-load time. Solutions to the latter problem, including simply standardizing communication and control protocols of vehicle's chargers so that utilities can control when they turn on and off, have already been proposed.
I'm not arguing that distributed generation is a bad idea -- on the contrary, I think it's a good idea, and the way of the future. However, my point is that it will require a different, and more sophisticated, command and control system than currently exists. Having millions of generators capable of going on- and off-line uncontrollably is not a way to present clean, reliable power to those who need it. One (relatively well-studied) problem is that the generation of power from these sources would not be independent -- on sunny days, for example, people generating via solar power would typically generate more power than they need, and offer their surplus to the utility. However, since they are all generating all the power they need themselves, the utility has less need for this power -- its value exists only in its lower cost (to the utility) relative to other generation methods, to be supplied to non-solar users (typically concentrated loads like industrial plants). This correlation in offered power from ostensibly independent sources would need to be characterized and compensated for in the design of the utility grid. Similarly, if the solar generators are all in the suburb or rural areas, and the loads were in concentrated urban industrial areas, transmission facilities would need to be present between the rural and urban locations -- which is not, typically, where they are now.
I think you'll find the control problem, whether centralized or distributed, is orders of magnitude more complex than you envision. The hard part isn't the economic part, it's the electrical part: Maintaining a constant amplitude (i.e., voltage), frequency, and phase over a large (both in geographic area and node order) network, with limited ability to transfer power from one point to another, is a very difficult problem -- especially when one has limited control over the applied load, and limited generating capacity. Not to mention all the problems with reactive power due to the uncontrolled nature of the loads (frequently inductive) and the phase delays that occur over distance. Much more information is needed besides "quantity produced vs. consumed."
The "can not get what is not there" option is amusing to utilities. The more common name for this option is a "brownout" or "blackout" and, even if only local, they typically result in nastygrams sent to relevant regulatory bodies, political officials, and the press. They are therefore to be avoided. From an engineering standpoint this is typically achieved by finding someplace where power is available, and making it available where it is not. This requires a network of transmission lines. The second major headache of utilities today (and related to their first headache, lack of generating capacity to meet their growing loads) is that the transmission system frequently is operating near peak capacity and, during the peak times (usually July afternoons in the US), it is getting more and more difficult to get sufficient electricity to the right places to avoid the "can not get what is not there" option.
I think the difference is that in your example the cost to the utility of the attack is that the attacker, and only the attacker, gets free power. That's obviously not what anyone at the utility wants, but until the number of people attacking in this way steal enough power that it costs the utility more in power than it does to equip everybody with more secure cards, it's actually the correct business decision to let the few steal.
In the Smart Grid example, the entire grid could (conceivably) get pwned; it's hard to think of a level of security that would not be justified to save your entire network. There's a psychological difference, too: Most "security" efforts are really just a posteriori face-saving methods or CYA activities. Big PHBs think in big terms, and would view a loss of "their" system very personally.
I can't speak to the P2030 effort, but be advised that after the WEP debacle, no standard gets through 802 without a thorough security vetting. It's not a formal process, but no one wants to repeat that error. (Making new errors is conceivably acceptable, but remaking old, very famous, errors, not so much.)
A final point: One of the features of Smart Grid technology of most interest to utilities in the second and third world isn't decentralized generation or load shedding but the detailed metering capabilities it provides, enabling the location of "power leaks" to be determined with high precision. (There are utilities from which 50% of power generated is stolen. Theft leads to higher rates for everybody, which leads to still more theft, which...)
Decentralized power generation is a major part of the Smart Grid initiative. See, e.g., the Galvin Electricity Initiative.
Since power generated in a grid cannot be effectively stored, it must be used when generated. This forces today's utilities into a large control problem, in which consumers' needs (in the form of measurements of line voltage and frequency, sampled throughout the network) are fed back to centralized control points and used to control the output of a relatively small number of generating plants (and current sent along individual transmission lines). Control of this system is moderately well understood, if one accepts that certain heuristics have to be used -- along with occasional human judgement. Considering its complexity, this is one of the great engineering achievements of the 20th Century.
Decentralized power generation, however, is a completely different type of control problem. With millions of potential generators, the existing control algorithms fail completely; further, as part of the decentralized control algorithm the utility needs to communicate with each power meter (a.k.a. potential generator) in essentially real time, to control any power it may generate.
Having a meter that bills the customer only for the net of power used and generated is termed "net metering." This exists today, but cannot achieve wide-spread use without better communication with the meters. Utilities like net metering, because they get additional generating capacity without paying for new power plants.
The Smart Grid, with its communication to individual power meters, effectively enables net metering: Homeowners can generate their own power, use what they need locally, then sell any surplus to the utility for use by others. The meter can inform the utility how much power it is supplying at any time, a number used by the utility to maintain network stability. If the utility has no use for the power at that moment, it can refuse the offer, again by communicating with the meter.
There is no single "Smart Grid" device technology. At present there are many proprietary solutions from many different vendors, each using different communication protocols, computer hardware and firmware, and security methods. Each one of these vendors has its products in a very, very small fraction of the utility meters in the nation, most of which, of course, have no Smart technology at all. So the fact that these guys found one architecture vulnerable to a particular stack-overflow attack is bad for the vendor(s) that use it, but not indicative of an approacing nationwide catastrophe.
Smart Grid system standards are under development, however, and those doing the development are exceedingly aware of the need for high security. The IEEE, for example, recently started a Smart Grid standardization effort, P2030, and the IEEE 802.15.4g Smart Utility Neighborhood Task Group effort is already underway. Since the utilities lose revenue -- potentially all revenue, plus destruction of capital assets -- if their equipment is cracked, they are very much a part of these standard development activities, and security is of constant concern. (There will undoubtedly be an industry consortium tasked with reviewing implementations of these standards.)
It's the most unique math book I've ever read. There is no prose in the book per se; rather, the book is a series of small tasks and questions (usually starting by identifying patterns in tables of numbers) that, as the title suggests, gently lead the reader into Number Theory. All the major topics of a first course (the fundamental theorem of arithmetic, quadratic residues and forms, etc.) are there; the beauty of the book is that each task is such a small step from the previous one that the reader is led painlessly to a mastery of each concept. (Just don't skip steps!) This feature makes is suitable for advanced high school students looking for "stimulating mathematical ideas."
It's a wonderful book, on a wonderful subject. I have often wished for books written in this format on other mathematics subjects.
The IEEE 802 Working Group for TV white space is the 802.22 group. Early on in the work of this group it was recognized that it was important to detect the presence of wireless microphones, for just the reasons you describe. Their solution was the development of a beacon protocol, to be transmitted in the same TV channel as that used by the microphone. (The microphone uses much less than the full TV channel bandwidth, so there is room to do this.) The beacon is carefully crafted to be quickly detectable by the secondary user at long range, even in the presence of severe multipath distortion, and is intended to be placed at the wireless microphone receiver. In this way, scanning secondary users are much more likely to detect that the channel is occupied, and move elsewhere.
With luck, Google & Co. will adapt this or a similar scheme.
...but if your wireless mics really are in the TV bands, and really aren't Part 15 devices, then they're Part 74, Subpart H devices, which do require a license. There are no other options. You're one of many who've been sold a bill of goods by unscrupulous manufacturers of these microphones which, by law, can only be licensed to television stations, broadcast networks, cable television systems, motion picture producers, television program producers, and Multipoint Multichannel Distribution System (MMDS) licensees (Title 47 USC, 74.832). See this for a pretty good, if slightly dated, FAQ on what's required to license a wireless microphone in the US.
These microphones typically will be offered no protection against interference from whitespace protocols like the IEEE 802.22 standard. Note that the IEEE 802.22 group is also in the final stages of standardizing a beacon protocol, IEEE 802.22.1 [pdf]. This beacon is to be present whenever the (licensed) wireless microphone is in operation, and produces a signal easier to detect (at a greater range) than the microphone itself, so that cognitive white space secondary users can more reliably determine that that television channel is occupied and move elsewhere. This system avoids interference to the wireless microphone by the secondary user.
The structure could not be solved from experimental data alone, and required a new theoretical method that was developed by Dr. Oganov at the time [2004].
"The method is a purely theoretical, requires no experimental information, and is based on ideas of natural evolution applied to the search for the most stable crystal structure," said Dr. Oganov. "The computer generates dozens of trial crystal structures, whose energies are evaluated using quantum-mechanical calculations, and the most favorable of the sampled structures mate and mutate to produce child structures until the most stable structure is found."
This part of TFA puzzled me. What he's describing is a genetic optimization algorithm, which has been known for decades. I looked up the full text of the Nature article, which doesn't claim novelty in its theoretical method, but does name the software used -- USPEX.
USPEX is a specific software package co-developed by Dr. Oganov, the lead author of the paper. I think his comments on how it works -- which are generic and quite correct -- were misinterpreted by the ScienceDaily reporter, who has done Dr. Oganov a disservice. USPEX was new in 2004; the concept of genetic optimization was not.
I was... the first American that many Chinese seen (sic) since the Chiang Kai-shek stuff from the 50's and 60's.
Chiang left the mainland in 1949. During the 1950s and 1960s he was President of the ROC, of course, but I wasn't aware of any significant numbers of Americans on the mainland during this period, the height of the Cold War. Did you mean "the 1940s," or is there a facet of Sino-American relations of which I am not aware?
If an interface concept is used in a movie and it is eventually turned into a real product and patented, does the implementation in the movie count as prior art?
Yes, it does, at least in the US.
The US statute reads, in relevant part, "A person shall be entitled to a patent unless-- (a) the invention was known or used by others in this country, or patented or described in a printed publication in this or a foreign country, before the invention thereof by the applicant for patent..." (35 USC 102)
Since finding printed art is a much stronger argument than, say, having sworn depositions from individuals in this country stating that they "knew" of the invention before the applicant claims to have invented it -- it's hard to cross-examine a scientific journal article -- that's usually the way these things go. The courts have a very broad interpretation of "printed," so don't worry, it doesn't have to be on paper. The emphasis is on "publication," i.e., available to the public.
[IANAL, but I've been down this road a few times.]
I hate to break this to you, but neither one of those initiatives is unique to Cisco. Both of those were corporate initiatives at Motorola while she was there, and they weren't even novel then -- most companies had them, the green initiative due to EU regulations and public relations in general, and the breaking down of silos because it was the latest wave in management self-help books. (Motorola, in particular, had a severe silo problem, known as the "warring tribes.")
After watching her career for the last ten years, this is par for the course. She is absolutely not a "forward thinking technologist" -- her career over this time has been a series of steps in which she took her "vision" from her superiors, trashed her own organization, then moved on before the mess became apparent to those above her. Just look at the organizations she's left: Motorola's Semiconductor Products Sector (now spun out as Freescale Semiconductor) and Motorola itself (in which Motorola labs, the corporate research arm of the company she once led, is now down to less than 300 individuals, less than ten percent of which are engaged in wireless research). Not to mention the company's centralized software group (over 3000 individuals) which she also led, that was disbanded upon her departure.
Does that sound like the work of a forward thinking technologist?
In the first part of my comment, I said, "...the cochannel APs are physically separated as much as possible."
This, of course, is true only both APs are part of your LAN, and isn't really appropriate here. (*sigh* You can take a horse to "Preview," but you can't make him think.) In your case, one might consider the opposite strategy: Place your cochannel AP as close to your neighbor's as possible (e.g., on the other side of the wall from his), and use a directional antenna (pointed into your place, of course). This would tend to produce a constant signal-to-interference ratio throughout your place, hopefully high enough to be useful, while not producing interference in your neighbor's place high enough to corrupt his network. I guess while you were buying directional antennas you could buy one for your neighbor, too, which could only help matters.
Of course, the contrarian view is to place your AP against the wall with its present antenna, and force your neighbor to worry about interference, buy antennas, etc.:-/
The answers are generalities, since each situation is unique. As others have already said, the real solution to your problem is spelled "5 GHz." However, if we add the condition that you must remain at 2.4, here we go:
With nine access points, for example, is it better to have three APs each on 1, 6 and 11, so that each completely overlaps with only two others. Or is it best to distribute those APs across nine channels such that they only partially overlap others (but potentially overlap more APs in total)?
In general, the former is best. Most site planning is done this way, with the (I hope obvious) additional condition that the cochannel APs are physically separated as much as possible.
Do use patterns affect interference? For example, is it best to overlap a channel with multiple APs that rarely transfers data, or to share a channel with one person who downloads torrents 24/7?
Yes, use patterns affect interference. In general, the former is best, since the channel has more idle time available for "your" data.
Does maximum data rate affect interference or robustness to interference? I found out by accident that setting my access point to '802.11b only' mode appeared to give me a vastly more reliable connection that leaving it in 'mixed 802.11b/g.' Is this a fluke? Or does transmitting at 10 Mbps when everyone else is using 54 Mbps (for their 3 Mbps DSL pipes!) give you a true advantage?"
Maximum data rate has a major effect on interference robustness. As you've found, in general lower rates can tolerate higher levels of interference than can higher rates. More explicitly, there's a range of interference levels (low) at which both will work. Above this is a range of interference levels (medium) at which the low rate will work and the high rate won't. Above this is a range of interference levels (high) at which both will not work. What you've found is that you're in the medium category, in which your system will work at 10 Mbps in the presence of interference from your neighbor's 54 Mbps system, but your system will not work at 54 Mbps in the presence of the same interference.
A second phenomenon may also be present, one specific to the 802.11g standard. To make it backwards compatible (i.e., so that an 11g AP would work in a network having one or more 11b devices) the 802.11g folk mandated a behavior in which an AP checks first to see what's around it. If it hears an 11b device, it downshifts into 11b. This, of course, slows the entire 54 Mbps network down to 10 Mbps. You may be experiencing a side effect of this -- all the checking and upshifting and downshifting takes time, so if 11b devices come and go frequently (as they might in your scenario) the net throughput can be less than if one stayed at 11b speeds in the first place.
Yeah, it's a little different in the USA, because politically research institutions (being the "intellectual elite") are frequently threatened with funding cuts (their lump sum public financing), or complete elimination. Remember, this is the place that cancelled funding for the Superconducting Super Collider, ceding dominance of basic physics research to Europe. (An example of the political winds faced by the SSC, and typical of those facing US publicly-funded research in general, is here. Note the emphasis on short-term economic return from the research investment.) There are a lot of people in powerful political places in the US (at least in the recent past) who would be quite happy if there were "less places for research."
It is also true that, as you say, IP royalties are a good defense against claims of "academic elitism," since royalties are received only when a product is sold commercially (and is, therefore, assumed to be adjudged useful by the market). However, it has been my experience that in the US this defense is typically used by research institutions to avoid budget cuts, rather than to apply for funding for more research facilities. The latter is typically done based on the expected value of the proposed research itself.
*sigh* Let me put it this way: If Bayh-Dole were recinded, the university research institutions would be suddenly short $45 billion. Who do you think they would ask to make up for the shortfall?
...because it's worth more to taxpayers if royalties go back to the inventive institiutions. In that way, the institutions can become partially self-funding, and the direct load on the taxpayer can be reduced. Said another way, royalties received from the private sector displace public funds that then may be used elsewhere. (This was the thought behind the Bayh-Dole act.)
Besides, seniors are already going to get cheap iShoes -- the company is seeking federal funds to bring the product to market. If it had to go to investors to get its $3-4 million, they would want to be paid back with interest, out of funds ultimately coming from the price of the iShoes. With public funding, that's not a problem. (And whatever the royalty agreement is -- neither one of us knows -- it's very unlikely that the royalties are anywhere near the amortized startup costs. At least for many years to come.)
3. While an intern, Lieberman was also a federally-funded (i.e., taxpayer-supported) graduate student, receiving money from both the National Science Foundation and Department of Defense, through his university, for his research. Like many (perhaps substantially all) graduate researchers in US universities, he was being paid by his university to do research. The fact that the research was being conducted at NASA doesn't change the fact that Lieberman was on the university payroll at the time the invention was made. Welcome to internships.
4. His company has also filed for federal funding to develop the idea for market and, "[o]nce funding is obtained, the iShoe could be for sale in 18 months, Lieberman said." So he's still using taxpayer money to develop the invention for market.
5. We don't know what the "hefty royalty" is (unless I missed it, it's not in any of the linked articles), but $75,000 is peanuts. "The iShoe has a way to go to reach the market [...] Lieberman estimates $1 million is needed for a broad clinical trial, and $3 million to $4 million to bring the insole to market." As a startup, his monthly burn rate will be much more than $75,000.
Frankly, I'm fine with institutions receiving a financial return on the work of their paid employees -- especially if taxpayers are ultimately footing the bill. In fact, I would argue that Mr. Lieberman is getting a sweetheart deal; I think once he gets into industry himself he'll find that the commercial sector typically requires employees to assign all rights to any future inventions (at least, in the company's field of interest) to their employer starting on Day 1, usually with trivial or no compensation.
It will be interesting to see what intellectual property policy the new iShoe company establishes for its own employees. As CEO, will Lieberman let his iShoe researchers invent and patent without expecting that those inventions will belong to iShoe?
Volcanic "ash" is not burning wood "ash". Volcanic ash is actually pulverized, powdered rock that only superficially resembles wood ash as it falls and collects on the ground. It's not the result of any burning process.
How can someone spend so much time so close to computers and not becoming almost an expert on them? In fact, how can an intelligent and curious mind, which professors are supposed to possess, even just use computers daily and still not figure them out much?
I'll tell you how. I have a Ph.D. in Computer Engineering and a Masters of Science in Electrical Engineering. (I could be your professor, in fact.) The study of computing is much deeper than familiarity with the latest (or even the not-so-latest) programming or OS features. I, at least, figure that that stuff comes and goes, and don't really pay that much attention to it. A computer, to me, is a very abstract programming engine, limited by specific features of its architecture and programming structure; what one actually does with that engine is of little or no interest. Any time I spend (with my "intelligent and curious mind") reading up on the latest OS or programming fad (even if I were so inclined) would be time away from my work.
So I ignore it.
This thread reminds me of the debate some time back about why one never sends an electrical engineer to repair a TV set. The engineer may even have been a member of the ATSC, and know the details of the video communications protocol, but would be totally unfamiliar with, say, Sony's TV product line, and know nothing at all of what's in the box. He might be interested in listening to someone describe Sony's implementation of some feature, but he's not going to be knowledgeable on every (or perhaps any) television feature on the market. His interests are elsewhere.
I tried to do this just last week. I pasted the second screenshot in the email, then went to do something else. When I returned a few minutes later, the second screenshot was gone, and had been replaced with a duplicate of the first! After some investigation, it turned out that (at least on my company's version of Outlook) the problem is in the save routine, and the second screenshot was being replaced by a duplicate of the first during an autosave. You could demo the bug on demand just by saving the email you were trying to compose.
I ended up sending the guy two emails, each with one screenshot.
In addition to the list of controls for each country, most people are really, really surprised to read the list of controlled items -- the Commerce Control List. The list itself is Part 774, Catetegories 0 through 9, plus Supplements 2 and 3, linked at the bottom of the page.
One concept not well-known is that merely discussing a controlled technology in the presence of a foreign national from the "wrong" country (think China and Iran, among others) is considered an "export" of technology, and has federal penalties (fines and prison time) just as severe as the actual physical transfer of an object. This tripped up J. Reese Roth, a retired professor now facing a maximum of 150 years in prison. Sentencing is scheduled for 7 January 2009.
In case some are from warmer climes and don't know what the fuss with ice storms is all about, here are a couple of damage scenes for your perusal. Basically, ice builds up on all external surfaces of a structure until either (a) the weight of the ice causes the structure to collapse, or (b) the surface area of the structure is increased to the point that the wind in the storm blows the structure over.
Scroll down to December 12 and 14 in the maintenance and upgrade blog to see pictures of the ice storm damage at the K1TTT station in Peru, Massachusetts. His December 15 entry lists the damage, and subsequent entries begin the long process of rebuilding.
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No, the purpose of "current limiting" is to get more control over the system peak loads, since the utilites (for a variety of good reasons, including environmental and regulatory concerns, and a variety of poor reasons, notably NIMBY problems) have been unable to increase generating and transmission capacity as fast as peak loads have been increasing.
Very true. This is not a panacea, however, as utilities' peak load is typically around 5 PM (1700) local time, when most cars are not attached to the grid, and most drivers typically would plug in their vehicles in the evening, a high-load time. Solutions to the latter problem, including simply standardizing communication and control protocols of vehicle's chargers so that utilities can control when they turn on and off, have already been proposed.
I'm not arguing that distributed generation is a bad idea -- on the contrary, I think it's a good idea, and the way of the future. However, my point is that it will require a different, and more sophisticated, command and control system than currently exists. Having millions of generators capable of going on- and off-line uncontrollably is not a way to present clean, reliable power to those who need it. One (relatively well-studied) problem is that the generation of power from these sources would not be independent -- on sunny days, for example, people generating via solar power would typically generate more power than they need, and offer their surplus to the utility. However, since they are all generating all the power they need themselves, the utility has less need for this power -- its value exists only in its lower cost (to the utility) relative to other generation methods, to be supplied to non-solar users (typically concentrated loads like industrial plants). This correlation in offered power from ostensibly independent sources would need to be characterized and compensated for in the design of the utility grid. Similarly, if the solar generators are all in the suburb or rural areas, and the loads were in concentrated urban industrial areas, transmission facilities would need to be present between the rural and urban locations -- which is not, typically, where they are now.
I think you'll find the control problem, whether centralized or distributed, is orders of magnitude more complex than you envision. The hard part isn't the economic part, it's the electrical part: Maintaining a constant amplitude (i.e., voltage), frequency, and phase over a large (both in geographic area and node order) network, with limited ability to transfer power from one point to another, is a very difficult problem -- especially when one has limited control over the applied load, and limited generating capacity. Not to mention all the problems with reactive power due to the uncontrolled nature of the loads (frequently inductive) and the phase delays that occur over distance. Much more information is needed besides "quantity produced vs. consumed."
The "can not get what is not there" option is amusing to utilities. The more common name for this option is a "brownout" or "blackout" and, even if only local, they typically result in nastygrams sent to relevant regulatory bodies, political officials, and the press. They are therefore to be avoided. From an engineering standpoint this is typically achieved by finding someplace where power is available, and making it available where it is not. This requires a network of transmission lines. The second major headache of utilities today (and related to their first headache, lack of generating capacity to meet their growing loads) is that the transmission system frequently is operating near peak capacity and, during the peak times (usually July afternoons in the US), it is getting more and more difficult to get sufficient electricity to the right places to avoid the "can not get what is not there" option.
I think the difference is that in your example the cost to the utility of the attack is that the attacker, and only the attacker, gets free power. That's obviously not what anyone at the utility wants, but until the number of people attacking in this way steal enough power that it costs the utility more in power than it does to equip everybody with more secure cards, it's actually the correct business decision to let the few steal.
In the Smart Grid example, the entire grid could (conceivably) get pwned; it's hard to think of a level of security that would not be justified to save your entire network. There's a psychological difference, too: Most "security" efforts are really just a posteriori face-saving methods or CYA activities. Big PHBs think in big terms, and would view a loss of "their" system very personally.
I can't speak to the P2030 effort, but be advised that after the WEP debacle, no standard gets through 802 without a thorough security vetting. It's not a formal process, but no one wants to repeat that error. (Making new errors is conceivably acceptable, but remaking old, very famous, errors, not so much.)
A final point: One of the features of Smart Grid technology of most interest to utilities in the second and third world isn't decentralized generation or load shedding but the detailed metering capabilities it provides, enabling the location of "power leaks" to be determined with high precision. (There are utilities from which 50% of power generated is stolen. Theft leads to higher rates for everybody, which leads to still more theft, which...)
Decentralized power generation is a major part of the Smart Grid initiative. See, e.g., the Galvin Electricity Initiative.
Since power generated in a grid cannot be effectively stored, it must be used when generated. This forces today's utilities into a large control problem, in which consumers' needs (in the form of measurements of line voltage and frequency, sampled throughout the network) are fed back to centralized control points and used to control the output of a relatively small number of generating plants (and current sent along individual transmission lines). Control of this system is moderately well understood, if one accepts that certain heuristics have to be used -- along with occasional human judgement. Considering its complexity, this is one of the great engineering achievements of the 20th Century.
Decentralized power generation, however, is a completely different type of control problem. With millions of potential generators, the existing control algorithms fail completely; further, as part of the decentralized control algorithm the utility needs to communicate with each power meter (a.k.a. potential generator) in essentially real time, to control any power it may generate.
Having a meter that bills the customer only for the net of power used and generated is termed "net metering." This exists today, but cannot achieve wide-spread use without better communication with the meters. Utilities like net metering, because they get additional generating capacity without paying for new power plants.
The Smart Grid, with its communication to individual power meters, effectively enables net metering: Homeowners can generate their own power, use what they need locally, then sell any surplus to the utility for use by others. The meter can inform the utility how much power it is supplying at any time, a number used by the utility to maintain network stability. If the utility has no use for the power at that moment, it can refuse the offer, again by communicating with the meter.
This is non-news.
There is no single "Smart Grid" device technology. At present there are many proprietary solutions from many different vendors, each using different communication protocols, computer hardware and firmware, and security methods. Each one of these vendors has its products in a very, very small fraction of the utility meters in the nation, most of which, of course, have no Smart technology at all. So the fact that these guys found one architecture vulnerable to a particular stack-overflow attack is bad for the vendor(s) that use it, but not indicative of an approacing nationwide catastrophe.
Smart Grid system standards are under development, however, and those doing the development are exceedingly aware of the need for high security. The IEEE, for example, recently started a Smart Grid standardization effort, P2030, and the IEEE 802.15.4g Smart Utility Neighborhood Task Group effort is already underway. Since the utilities lose revenue -- potentially all revenue, plus destruction of capital assets -- if their equipment is cracked, they are very much a part of these standard development activities, and security is of constant concern. (There will undoubtedly be an industry consortium tasked with reviewing implementations of these standards.)
A Pathway Into Number Theory, by R. P. Burn.
It's the most unique math book I've ever read. There is no prose in the book per se; rather, the book is a series of small tasks and questions (usually starting by identifying patterns in tables of numbers) that, as the title suggests, gently lead the reader into Number Theory. All the major topics of a first course (the fundamental theorem of arithmetic, quadratic residues and forms, etc.) are there; the beauty of the book is that each task is such a small step from the previous one that the reader is led painlessly to a mastery of each concept. (Just don't skip steps!) This feature makes is suitable for advanced high school students looking for "stimulating mathematical ideas."
It's a wonderful book, on a wonderful subject. I have often wished for books written in this format on other mathematics subjects.
The IEEE 802 Working Group for TV white space is the 802.22 group. Early on in the work of this group it was recognized that it was important to detect the presence of wireless microphones, for just the reasons you describe. Their solution was the development of a beacon protocol, to be transmitted in the same TV channel as that used by the microphone. (The microphone uses much less than the full TV channel bandwidth, so there is room to do this.) The beacon is carefully crafted to be quickly detectable by the secondary user at long range, even in the presence of severe multipath distortion, and is intended to be placed at the wireless microphone receiver. In this way, scanning secondary users are much more likely to detect that the channel is occupied, and move elsewhere.
With luck, Google & Co. will adapt this or a similar scheme.
...but if your wireless mics really are in the TV bands, and really aren't Part 15 devices, then they're Part 74, Subpart H devices, which do require a license. There are no other options. You're one of many who've been sold a bill of goods by unscrupulous manufacturers of these microphones which, by law, can only be licensed to television stations, broadcast networks, cable television systems, motion picture producers, television program producers, and Multipoint Multichannel Distribution System (MMDS) licensees (Title 47 USC, 74.832). See this for a pretty good, if slightly dated, FAQ on what's required to license a wireless microphone in the US.
These microphones typically will be offered no protection against interference from whitespace protocols like the IEEE 802.22 standard. Note that the IEEE 802.22 group is also in the final stages of standardizing a beacon protocol, IEEE 802.22.1 [pdf]. This beacon is to be present whenever the (licensed) wireless microphone is in operation, and produces a signal easier to detect (at a greater range) than the microphone itself, so that cognitive white space secondary users can more reliably determine that that television channel is occupied and move elsewhere. This system avoids interference to the wireless microphone by the secondary user.
This part of TFA puzzled me. What he's describing is a genetic optimization algorithm, which has been known for decades. I looked up the full text of the Nature article, which doesn't claim novelty in its theoretical method, but does name the software used -- USPEX.
USPEX is a specific software package co-developed by Dr. Oganov, the lead author of the paper. I think his comments on how it works -- which are generic and quite correct -- were misinterpreted by the ScienceDaily reporter, who has done Dr. Oganov a disservice. USPEX was new in 2004; the concept of genetic optimization was not.
Chiang left the mainland in 1949. During the 1950s and 1960s he was President of the ROC, of course, but I wasn't aware of any significant numbers of Americans on the mainland during this period, the height of the Cold War. Did you mean "the 1940s," or is there a facet of Sino-American relations of which I am not aware?
Yes, it does, at least in the US.
The US statute reads, in relevant part, "A person shall be entitled to a patent unless-- ..." (35 USC 102)
(a) the invention was known or used by others in this country, or patented or described in a printed publication in this or a foreign country, before the invention thereof by the applicant for patent
Since finding printed art is a much stronger argument than, say, having sworn depositions from individuals in this country stating that they "knew" of the invention before the applicant claims to have invented it -- it's hard to cross-examine a scientific journal article -- that's usually the way these things go. The courts have a very broad interpretation of "printed," so don't worry, it doesn't have to be on paper. The emphasis is on "publication," i.e., available to the public.
[IANAL, but I've been down this road a few times.]
I hate to break this to you, but neither one of those initiatives is unique to Cisco. Both of those were corporate initiatives at Motorola while she was there, and they weren't even novel then -- most companies had them, the green initiative due to EU regulations and public relations in general, and the breaking down of silos because it was the latest wave in management self-help books. (Motorola, in particular, had a severe silo problem, known as the "warring tribes.")
After watching her career for the last ten years, this is par for the course. She is absolutely not a "forward thinking technologist" -- her career over this time has been a series of steps in which she took her "vision" from her superiors, trashed her own organization, then moved on before the mess became apparent to those above her. Just look at the organizations she's left: Motorola's Semiconductor Products Sector (now spun out as Freescale Semiconductor) and Motorola itself (in which Motorola labs, the corporate research arm of the company she once led, is now down to less than 300 individuals, less than ten percent of which are engaged in wireless research). Not to mention the company's centralized software group (over 3000 individuals) which she also led, that was disbanded upon her departure.
Does that sound like the work of a forward thinking technologist?
In the first part of my comment, I said, "...the cochannel APs are physically separated as much as possible."
This, of course, is true only both APs are part of your LAN, and isn't really appropriate here. (*sigh* You can take a horse to "Preview," but you can't make him think.) In your case, one might consider the opposite strategy: Place your cochannel AP as close to your neighbor's as possible (e.g., on the other side of the wall from his), and use a directional antenna (pointed into your place, of course). This would tend to produce a constant signal-to-interference ratio throughout your place, hopefully high enough to be useful, while not producing interference in your neighbor's place high enough to corrupt his network. I guess while you were buying directional antennas you could buy one for your neighbor, too, which could only help matters.
Of course, the contrarian view is to place your AP against the wall with its present antenna, and force your neighbor to worry about interference, buy antennas, etc. :-/
The answers are generalities, since each situation is unique. As others have already said, the real solution to your problem is spelled "5 GHz." However, if we add the condition that you must remain at 2.4, here we go:
In general, the former is best. Most site planning is done this way, with the (I hope obvious) additional condition that the cochannel APs are physically separated as much as possible.
Yes, use patterns affect interference. In general, the former is best, since the channel has more idle time available for "your" data.
Maximum data rate has a major effect on interference robustness. As you've found, in general lower rates can tolerate higher levels of interference than can higher rates. More explicitly, there's a range of interference levels (low) at which both will work. Above this is a range of interference levels (medium) at which the low rate will work and the high rate won't. Above this is a range of interference levels (high) at which both will not work. What you've found is that you're in the medium category, in which your system will work at 10 Mbps in the presence of interference from your neighbor's 54 Mbps system, but your system will not work at 54 Mbps in the presence of the same interference.
A second phenomenon may also be present, one specific to the 802.11g standard. To make it backwards compatible (i.e., so that an 11g AP would work in a network having one or more 11b devices) the 802.11g folk mandated a behavior in which an AP checks first to see what's around it. If it hears an 11b device, it downshifts into 11b. This, of course, slows the entire 54 Mbps network down to 10 Mbps. You may be experiencing a side effect of this -- all the checking and upshifting and downshifting takes time, so if 11b devices come and go frequently (as they might in your scenario) the net throughput can be less than if one stayed at 11b speeds in the first place.
Yeah, it's a little different in the USA, because politically research institutions (being the "intellectual elite") are frequently threatened with funding cuts (their lump sum public financing), or complete elimination. Remember, this is the place that cancelled funding for the Superconducting Super Collider, ceding dominance of basic physics research to Europe. (An example of the political winds faced by the SSC, and typical of those facing US publicly-funded research in general, is here. Note the emphasis on short-term economic return from the research investment.) There are a lot of people in powerful political places in the US (at least in the recent past) who would be quite happy if there were "less places for research."
It is also true that, as you say, IP royalties are a good defense against claims of "academic elitism," since royalties are received only when a product is sold commercially (and is, therefore, assumed to be adjudged useful by the market). However, it has been my experience that in the US this defense is typically used by research institutions to avoid budget cuts, rather than to apply for funding for more research facilities. The latter is typically done based on the expected value of the proposed research itself.
*sigh* Let me put it this way: If Bayh-Dole were recinded, the university research institutions would be suddenly short $45 billion. Who do you think they would ask to make up for the shortfall?
"Colleges and universities obtained fewer than 250 patents a year before 1980, when the Bayh-Dole Act gave them ownership of inventions developed through federally financed research. Now they acquire about 3,000 a year, according to the Association of University Technology Managers, whose members work in tech transfer offices. In 2006, association members made $45 billion from licensing fees and equity in spinoff companies; research powerhouses like Stanford and New York University made $61 million and $157 million, respectively."
...because it's worth more to taxpayers if royalties go back to the inventive institiutions. In that way, the institutions can become partially self-funding, and the direct load on the taxpayer can be reduced. Said another way, royalties received from the private sector displace public funds that then may be used elsewhere. (This was the thought behind the Bayh-Dole act.)
Besides, seniors are already going to get cheap iShoes -- the company is seeking federal funds to bring the product to market. If it had to go to investors to get its $3-4 million, they would want to be paid back with interest, out of funds ultimately coming from the price of the iShoes. With public funding, that's not a problem. (And whatever the royalty agreement is -- neither one of us knows -- it's very unlikely that the royalties are anywhere near the amortized startup costs. At least for many years to come.)
Let's keep a few things in mind:
1. This was "a technology he created as an intern at NASA in the summer of 2007." It's not like he was an undergraduate sitting in a classroom -- he was working for NASA when he made the invention.
2. "The iShoe researchers used some of their own work and previous NASA data ," the latter presumably taken with "an expensive device about the size of a phone booth" in the creation of their invention. So NASA's data (and presumably equipment) were needed to produce the invention.
3. While an intern, Lieberman was also a federally-funded (i.e., taxpayer-supported) graduate student, receiving money from both the National Science Foundation and Department of Defense, through his university, for his research. Like many (perhaps substantially all) graduate researchers in US universities, he was being paid by his university to do research. The fact that the research was being conducted at NASA doesn't change the fact that Lieberman was on the university payroll at the time the invention was made. Welcome to internships.
4. His company has also filed for federal funding to develop the idea for market and, "[o]nce funding is obtained, the iShoe could be for sale in 18 months, Lieberman said." So he's still using taxpayer money to develop the invention for market.
5. We don't know what the "hefty royalty" is (unless I missed it, it's not in any of the linked articles), but $75,000 is peanuts. "The iShoe has a way to go to reach the market [...] Lieberman estimates $1 million is needed for a broad clinical trial, and $3 million to $4 million to bring the insole to market." As a startup, his monthly burn rate will be much more than $75,000.
Frankly, I'm fine with institutions receiving a financial return on the work of their paid employees -- especially if taxpayers are ultimately footing the bill. In fact, I would argue that Mr. Lieberman is getting a sweetheart deal; I think once he gets into industry himself he'll find that the commercial sector typically requires employees to assign all rights to any future inventions (at least, in the company's field of interest) to their employer starting on Day 1, usually with trivial or no compensation.
It will be interesting to see what intellectual property policy the new iShoe company establishes for its own employees. As CEO, will Lieberman let his iShoe researchers invent and patent without expecting that those inventions will belong to iShoe?
Volcanic "ash" is not burning wood "ash". Volcanic ash is actually pulverized, powdered rock that only superficially resembles wood ash as it falls and collects on the ground. It's not the result of any burning process.
I'll tell you how. I have a Ph.D. in Computer Engineering and a Masters of Science in Electrical Engineering. (I could be your professor, in fact.) The study of computing is much deeper than familiarity with the latest (or even the not-so-latest) programming or OS features. I, at least, figure that that stuff comes and goes, and don't really pay that much attention to it. A computer, to me, is a very abstract programming engine, limited by specific features of its architecture and programming structure; what one actually does with that engine is of little or no interest. Any time I spend (with my "intelligent and curious mind") reading up on the latest OS or programming fad (even if I were so inclined) would be time away from my work.
So I ignore it.
This thread reminds me of the debate some time back about why one never sends an electrical engineer to repair a TV set. The engineer may even have been a member of the ATSC, and know the details of the video communications protocol, but would be totally unfamiliar with, say, Sony's TV product line, and know nothing at all of what's in the box. He might be interested in listening to someone describe Sony's implementation of some feature, but he's not going to be knowledgeable on every (or perhaps any) television feature on the market. His interests are elsewhere.
I tried to do this just last week. I pasted the second screenshot in the email, then went to do something else. When I returned a few minutes later, the second screenshot was gone, and had been replaced with a duplicate of the first! After some investigation, it turned out that (at least on my company's version of Outlook) the problem is in the save routine, and the second screenshot was being replaced by a duplicate of the first during an autosave. You could demo the bug on demand just by saving the email you were trying to compose.
I ended up sending the guy two emails, each with one screenshot.
Exports from US companies are controlled by the Bureau of Industry and Security, part of the Department of Commerce.
In addition to the list of controls for each country, most people are really, really surprised to read the list of controlled items -- the Commerce Control List. The list itself is Part 774, Catetegories 0 through 9, plus Supplements 2 and 3, linked at the bottom of the page.
One concept not well-known is that merely discussing a controlled technology in the presence of a foreign national from the "wrong" country (think China and Iran, among others) is considered an "export" of technology, and has federal penalties (fines and prison time) just as severe as the actual physical transfer of an object. This tripped up J. Reese Roth, a retired professor now facing a maximum of 150 years in prison. Sentencing is scheduled for 7 January 2009.
In case some are from warmer climes and don't know what the fuss with ice storms is all about, here are a couple of damage scenes for your perusal. Basically, ice builds up on all external surfaces of a structure until either (a) the weight of the ice causes the structure to collapse, or (b) the surface area of the structure is increased to the point that the wind in the storm blows the structure over.
This is the KC1XX amateur radio contest station in Mason, New Hampshire, after the storm. More than 1.5 inches of radial ice.
Scroll down to December 12 and 14 in the maintenance and upgrade blog to see pictures of the ice storm damage at the K1TTT station in Peru, Massachusetts. His December 15 entry lists the damage, and subsequent entries begin the long process of rebuilding.