Before SCO can successfully sue end users, they have to win the Novell suit and the IBM suit and the Red Hat suit.
If they lose the Novell suit, they don't have rights to UNIX they can enforce against others. If they lose the IBM suit, their wierd legal theory under which IBM "contaminated" Linux with IBM-developed code to which SCO has contractual rights goes away. And if they lose the Red Hat suit, there's an injunction against them preventing them from sueing end users.
Ambient Corporation seems to be more about hype than products. Their main product is a "coupler" that allows passing RF around transformers. Those have been around for years, although the Ambient one is easier to install than the usual capacitors.
Their new ideas revolve around ways to transmit data through underground power cables with multiple neutral wires. Big underground power cables are surrounded by multiple neutral wires, which has some shielding effect. The idea is to differentially drive those multiple neutral wires with RF. This is claimed to emit less external RF than driving the high voltage side of the line.
In cities with underground cable vaults, it's easier to wire fibre or coax. Either provides more bandwidth. Ambient only claims 10Mb/s, and that's per cable segment, not per end user.
This looks more like a specialized technology being overhyped than a major breakthrough.
You'd think that somebody would turn on a general-purpose receiver or a spectrum analyzer and find out what's emitting high-power RF in that band. It's not like this is rocket science. Some hams, most cell phone companies and the better Wi-Fi installers have one around someplace. Yes, it's an ISM band, but if there's interference over a wide area, somebody is way over allowed power. Any ordinary analog receiver should pick it up.
Back when the FCC had District Engineers, instead of "Regional Directors" who are usually lawyers, you could probably get somebody on the phone who'd crank up a receiver and tune around until they found the source of the problem. Today, the FCC doesn't even have an office in Las Vegas. The nearest field office is in LA.
There are archival quality CD-R blanks. These supposedly will last a century. But they're about $0.90 each and hard to find. I'm not aware of anybody making archival quality DVD media.
There's a tradeoff between writing speed and lifetime. The archival blanks use a different dye and slower writing speeds. (The control information for this is on the blank, and standard CD-R drives read it before writing.)
It's worth reading the actual article. It's been peer reviewed and is being published by the National Institutes of Health. The experimental approach seems sound and should be repeatable. The experimenters set up a pair of big coils and put rat cages between them, then tried various field strengths. They then killed the rats and analyzed brain DNA for breaks.
"The experiment was run under 'blind' condition, i.e., the experimenters who
prepared the slides and did the DNA strand-break, apoptosis, and necrosis measurements
did not know the treatment conditions of the animals from which the slides were
prepared."
They found some moderately significant differences betweent rats exposed to modest fields and those not exposed at all.
This isn't some statistical study where some big group in an uncontrolled environment shows some statistical anomaly. It's a straightforward experiment.
The main criticism of the study is that they need to try different field strengths, over at least a 1:10 range. If a clear relationship appears between field strength and DNA breaks, that provides a much stronger indication of a valid result.
That sounds like the AS&E backscatter X-ray machine.
That's the one that produces a nude image through clothing. Organic objects like drugs or explosives show up very nicely. So do metal objects like guns and knives. There have been complaints that the thing shows too much detail.
AS&E is working on a new model, one that's not so tall and costs less. (The height problem comes from the need for the detector to be at right angles to the scanning beam.) I'm waiting for this to show up at nightclubs.
They're clearly trying for static stability. Look at all that dihedral and the big winglets. But big dihedral angles tend to induce Dutch roll. With no tail, that's going to be a problem. They're doing well with the model, but if you watch the videos, there's a 1Hz or so roll oscillation.
That's a half-sized model, of course. The full sized one should oscillate at a lower rate.
It's possible to build very stable aircraft, but they have high drag, because the stabilizing aerodynamic forces are fighting each other.
Engine power can overcome this, which is what they're doing. This isn't a glider.
If this thing is ever flown successfully by a human, it's going to be an experienced test pilot who flies the thing. Someone who's flown very unstable aircraft. It's not going to be steered by leaning; it will need a full set of control surfaces. And they'll have to figure out some way to attach the pilot to the craft.
Actually, I had a long post on the theory and history of polymorphic viruses, and somehow posted only the last line. But that's all that's really needed. Just look up "polymorphic viruses".
Automatic eye testing has been around for a while. The first units appeared in the 1970s. Today, the technology is quite good. The Canon RK-F10 ("just press start") does a fully automatic "refraction" eye exam. Price is about $7000. This unit is overkill for just fitting glasses; the identical-seeming next model up in the same family ($12,000) collects the data needed for laser eye surgery and contact lens fitting, with all the liability issues that involves. So there's an opportunity for something more compact and at a lower price point.
It's too bad the original article doesn't say anything about how he makes lenses.
The current trick in low-cost eyeglass distribution for the third world is simply to use a kit of low-cost preformed round plastic lenses. Basic eyeglasses have a spherical component, a cylindrical component, and an axis for the cylindrical component.
The lenses are round, and can snap into the frames at different rotations, the number of different lenses needed goes down to a hundred or so.
And the whole kit fits in a briefcase.
Re:Why such a fat book?
on
Practical C++
·
· Score: 1
Complex and powerful tools require a certain level of detail to explain them,
It's not complexity or power. It's C++'s unusual combination of hiding and lack of safety.
This particular problem is unique to C++. C has neither hiding nor safety. Smalltalk, Java, Perl, and Python have both hiding and safety. C++ is the most complex programming language without memory safety.
(Incidentally, this is not due to the "power" of C++. It's due to some legacy design mistakes. C++ could be much safer, although retrofitting such safety without breaking existing code is very hard. I've tried; see my notes in "comp.std.c++.")
Stopping spam is easy. Make banks who issue merchant accounts liable for spam by their customers.
This would work. First, you can always find the bank handling the transaction. Just put in a credit card number and watch where the transaction comes from in the credit card system.
Second, banks have strong merchant agreements with companies that accept credit cards, agreements that allow the bank to charge back transactions. So banks can enforce anti-spam terms of service on their customers. Once this gets into the regulations of Visa International and MasterCard, it's enforceable worldwide through the credit card infrastructure.
Third, the seller/spammer always knows, when the transaction goes through, where the customer is.
So they are liable in the customer's jurisdiction, not the spammer's. If spam laws differ in different jurisdictions, the seller can block transactions from areas with strong anti-spam laws. Of course, if they have to block most of the developed world, they won't make any money, which makes spamming go away.
What is this mania for 900-page books on programming languages?
The original ALGOL-60 report was 19 pages. The original Scheme report was about 25 pages. Both were far more readable than the bloated trade paperbacks we have today.
We need short books that read like this:
Collection classes
The standard template library (STL) provides useful collection classes. These make it easier to build common data structures. Arrays of variable size "vector"), lists ("list"), and key/value pairs ("map") are provided.
Collection classes are provided as templates, so a collection of any desired type can be created. The type must be copyable ("operator=" must work), as objects are copied into the collection.
Some basic operations are provided for all collection types. [TABLE]. Each collection type also has its own operations.
Collections are not entirely safe. "vector" is not protected against subscripting out of range, and "list" is not protected against modification while iterating over the list. Checked versions of the STL exist, but are rare.
vector
"vector" creates a resizable array with elements of "typename". Elements can be added to the vector, which causes the vector to grow. This involves memory allocation and copying, so there's a performance penalty, but growth is managed reasonably efficiently by allocating some extra space at each growth.
"vector" offers the expected operations for a resizable array: [TABLE]...
All that verbiage just confuses people.
Copy of a stupid article
on
Practical C++
·
· Score: 2, Informative
So when are any of the 1,500 companies that received letters from SCO inviting them to purchase Linux licenses going to step up and complain to the US Postal Inspectors?
SCO is already in trouble in Germany and New Zealand for such things. In Germany, they're under an injunction not to send demand letters to Linux users, and in New Zealand, the Commerce Commission is looking into SCO's activities. "A person or a company falsely claiming to have ownership of a product or service or the rights to payment could breach the Fair Trading Act", says the spokesperson for the New Zealand Commerce Commission. There are also unconfirmed reports of investigations by the authorities in Australia and by the US Federal Trade Commission.
SCO's "sue and threaten everybody" strategy is backfiring.
If you look at what's actually happening with DSL and cable, the trend on bandwidth delivered to the end user is downward, not uppward. When DSL first launched, a typical product was SDSL with 1.5Mb/s in each direction. Now, entry level is 384/128Kb/sec, and you can't get more than 384Kb/s upstream DSL at any price. Even though the technology is symmetrical.
Cable modems show a similar trend, as cable companies hang more people on without adding more cable segments, routers, and fibre uplinks.
This is a marketing decision, not a technical one.
I've seen images of currency that contains the key pattern of five 1mm circles, but does anyone have a pure image of the trigger pattern, for general use in protecting documents?
In this Slashdot article back in 2000, I reported that vulnerability:
So this has been publicly known for years.
The...
decompressor for RLE-compressed.BMP files is in the kernel, and contains a buffer overflow.
You didn't need the source code to find that problem. I found it because I was creating compressed.BMP files and accidentally created one that crashed Win2K every time.
If Microsoft doesn't read Slashdot, that's their problem.
Owning a PDR indicates hypochondria
on
Cyberchondria
·
· Score: 1
It used to be said that owning a PDR (Physicians' Desk Reference, which is basically a set of data sheets for prescription drugs) if you're not in the medical field indicates hypochondria.
Actually, that's not quite right. Silly Window Syndrome occurs when the TCP window is almost full. The tinygram problem, which the Nagle algorithm addresses, occurs when the window is almost empty.
If I'd paid more attention to what Berkeley was doing with ACK delays, TCP would work better in that area today. Both algorithms went in around the same time, and they don't play well together.
I'm the head of Team Overbot, the guy whose picture is on the front page of the SF Chronicle today.
Sadly, we (Team Overbot) aren't going to be ready in time. We lost five members in January. Two got better jobs, and two were Stanford students who needed to get their grades back up. This left us with too few people to finish in time. We have all the hardware, and most of the software, Most of it is working, but it hasn't been integrated and tested. We'll finish the vehicle, and we'll have some public demos at some point, even if we're not at the Grand Challenge.
It's up to DARPA whether anyone wins this year.
They're going to provide 5000 GPS waypoints, and if you can drive the route described by connecting the dots, somebody will probably win. If the vehicle has to find its own gully crossing, it's unlikely that anyone will win, unless somebody figured out, by hand, in advance, where the crossing is. It's all up to DARPA. As one of the DARPA people put it, "This is turning into a breadcrumb following exercise". If somebody wins by connecting the dots, this whole thing was a waste of time.
Several teams are using aerial photographs and manual planning. The general route leaked weeks ago, and it's since been oveflown by Airborne 1 in San Diego. High-resolution photos and depth maps from LIDAR scans have been obtained. Still, you won't see a fence in those depth maps. The emphasis on preplanning surprised us. The whole point of the Grand Challenge was originally that preplanning was made impossible by the large area to be covered and the release of the waypoints only two hours before the race. That all changed when the route leaked.
Nobody seems to be deploying anything new in the sensor area. Everybody with a laser rangefinder that we know of is using an off-the-shelf line scanner. Nobody has a true 3D scanner, although several teams have line scanners on tilt heads.
It's quite possible to build a true 3D LIDAR depth measurement system. But it's hard to make money doing it, as the five companies that exited the field learned the hard way.
We hear talk of new vision algorithms, but no details yet. Stereo vision doesn't work well on dirt or sand; there aren't enough edges for the stereo algorithms to register the images properly.
Optical flow doesn't work well for the same reason.
If somebody can do good stereo from motion in this demanding environment, that will be an achievement.
Still, the Grand Challenge has done quite a bit to get autonomous vehicle work moving again. Just getting CMU off the dime (DARPA's real intent, we hear) was worth the whole effort.
If DARPA does this every year for the next decade, with a tougher course every time somebody wins, we will have battlefield robotics that works within ten years.
Slashdot Mirror
If they lose the Novell suit, they don't have rights to UNIX they can enforce against others. If they lose the IBM suit, their wierd legal theory under which IBM "contaminated" Linux with IBM-developed code to which SCO has contractual rights goes away. And if they lose the Red Hat suit, there's an injunction against them preventing them from sueing end users.
So quit worrying.
Their new ideas revolve around ways to transmit data through underground power cables with multiple neutral wires. Big underground power cables are surrounded by multiple neutral wires, which has some shielding effect. The idea is to differentially drive those multiple neutral wires with RF. This is claimed to emit less external RF than driving the high voltage side of the line.
In cities with underground cable vaults, it's easier to wire fibre or coax. Either provides more bandwidth. Ambient only claims 10Mb/s, and that's per cable segment, not per end user.
This looks more like a specialized technology being overhyped than a major breakthrough.
I wonder how many people are still waiting.
Back when the FCC had District Engineers, instead of "Regional Directors" who are usually lawyers, you could probably get somebody on the phone who'd crank up a receiver and tune around until they found the source of the problem. Today, the FCC doesn't even have an office in Las Vegas. The nearest field office is in LA.
There's a tradeoff between writing speed and lifetime. The archival blanks use a different dye and slower writing speeds. (The control information for this is on the blank, and standard CD-R drives read it before writing.)
This isn't some statistical study where some big group in an uncontrolled environment shows some statistical anomaly. It's a straightforward experiment.
The main criticism of the study is that they need to try different field strengths, over at least a 1:10 range. If a clear relationship appears between field strength and DNA breaks, that provides a much stronger indication of a valid result.
That sounds like the AS&E backscatter X-ray machine. That's the one that produces a nude image through clothing. Organic objects like drugs or explosives show up very nicely. So do metal objects like guns and knives. There have been complaints that the thing shows too much detail.
AS&E is working on a new model, one that's not so tall and costs less. (The height problem comes from the need for the detector to be at right angles to the scanning beam.) I'm waiting for this to show up at nightclubs.
It's possible to build very stable aircraft, but they have high drag, because the stabilizing aerodynamic forces are fighting each other. Engine power can overcome this, which is what they're doing. This isn't a glider.
If this thing is ever flown successfully by a human, it's going to be an experienced test pilot who flies the thing. Someone who's flown very unstable aircraft. It's not going to be steered by leaning; it will need a full set of control surfaces. And they'll have to figure out some way to attach the pilot to the craft.
Actually, I had a long post on the theory and history of polymorphic viruses, and somehow posted only the last line. But that's all that's really needed. Just look up "polymorphic viruses".
write better polymorphic viruses.
It's too bad the original article doesn't say anything about how he makes lenses.
The current trick in low-cost eyeglass distribution for the third world is simply to use a kit of low-cost preformed round plastic lenses. Basic eyeglasses have a spherical component, a cylindrical component, and an axis for the cylindrical component. The lenses are round, and can snap into the frames at different rotations, the number of different lenses needed goes down to a hundred or so. And the whole kit fits in a briefcase.
It's not complexity or power. It's C++'s unusual combination of hiding and lack of safety.
This particular problem is unique to C++. C has neither hiding nor safety. Smalltalk, Java, Perl, and Python have both hiding and safety. C++ is the most complex programming language without memory safety.
(Incidentally, this is not due to the "power" of C++. It's due to some legacy design mistakes. C++ could be much safer, although retrofitting such safety without breaking existing code is very hard. I've tried; see my notes in "comp.std.c++.")
There's a modest market in 800 numbers since number portability for them was introduced in 1993. What's the problem?
This would work. First, you can always find the bank handling the transaction. Just put in a credit card number and watch where the transaction comes from in the credit card system.
Second, banks have strong merchant agreements with companies that accept credit cards, agreements that allow the bank to charge back transactions. So banks can enforce anti-spam terms of service on their customers. Once this gets into the regulations of Visa International and MasterCard, it's enforceable worldwide through the credit card infrastructure.
Third, the seller/spammer always knows, when the transaction goes through, where the customer is. So they are liable in the customer's jurisdiction, not the spammer's. If spam laws differ in different jurisdictions, the seller can block transactions from areas with strong anti-spam laws. Of course, if they have to block most of the developed world, they won't make any money, which makes spamming go away.
We need short books that read like this:
- Collection classes
All that verbiage just confuses people.The standard template library (STL) provides useful collection classes. These make it easier to build common data structures. Arrays of variable size "vector"), lists ("list"), and key/value pairs ("map") are provided.
Collection classes are provided as templates, so a collection of any desired type can be created. The type must be copyable ("operator=" must work), as objects are copied into the collection.
Some basic operations are provided for all collection types. [TABLE]. Each collection type also has its own operations.
Collections are not entirely safe. "vector" is not protected against subscripting out of range, and "list" is not protected against modification while iterating over the list. Checked versions of the STL exist, but are rare.
vector
"vector" creates a resizable array with elements of "typename". Elements can be added to the vector, which causes the vector to grow. This involves memory allocation and copying, so there's a performance penalty, but growth is managed reasonably efficiently by allocating some extra space at each growth.
"vector" offers the expected operations for a resizable array: [TABLE] ...
The above rant was copied from here.
SCO is already in trouble in Germany and New Zealand for such things. In Germany, they're under an injunction not to send demand letters to Linux users, and in New Zealand, the Commerce Commission is looking into SCO's activities. "A person or a company falsely claiming to have ownership of a product or service or the rights to payment could breach the Fair Trading Act", says the spokesperson for the New Zealand Commerce Commission. There are also unconfirmed reports of investigations by the authorities in Australia and by the US Federal Trade Commission.
SCO's "sue and threaten everybody" strategy is backfiring.
Cable modems show a similar trend, as cable companies hang more people on without adding more cable segments, routers, and fibre uplinks.
This is a marketing decision, not a technical one.
I've seen images of currency that contains the key pattern of five 1mm circles, but does anyone have a pure image of the trigger pattern, for general use in protecting documents?
I sent a note to "tips" at securityfocus.
Go to the link to the article and search for "BMP". You'll find it.
You didn't need the source code to find that problem. I found it because I was creating compressed .BMP files and accidentally created one that crashed Win2K every time.
If Microsoft doesn't read Slashdot, that's their problem.
It used to be said that owning a PDR (Physicians' Desk Reference, which is basically a set of data sheets for prescription drugs) if you're not in the medical field indicates hypochondria.
If I'd paid more attention to what Berkeley was doing with ACK delays, TCP would work better in that area today. Both algorithms went in around the same time, and they don't play well together.
Sadly, we (Team Overbot) aren't going to be ready in time. We lost five members in January. Two got better jobs, and two were Stanford students who needed to get their grades back up. This left us with too few people to finish in time. We have all the hardware, and most of the software, Most of it is working, but it hasn't been integrated and tested. We'll finish the vehicle, and we'll have some public demos at some point, even if we're not at the Grand Challenge.
It's up to DARPA whether anyone wins this year. They're going to provide 5000 GPS waypoints, and if you can drive the route described by connecting the dots, somebody will probably win. If the vehicle has to find its own gully crossing, it's unlikely that anyone will win, unless somebody figured out, by hand, in advance, where the crossing is. It's all up to DARPA. As one of the DARPA people put it, "This is turning into a breadcrumb following exercise". If somebody wins by connecting the dots, this whole thing was a waste of time.
Several teams are using aerial photographs and manual planning. The general route leaked weeks ago, and it's since been oveflown by Airborne 1 in San Diego. High-resolution photos and depth maps from LIDAR scans have been obtained. Still, you won't see a fence in those depth maps. The emphasis on preplanning surprised us. The whole point of the Grand Challenge was originally that preplanning was made impossible by the large area to be covered and the release of the waypoints only two hours before the race. That all changed when the route leaked.
Nobody seems to be deploying anything new in the sensor area. Everybody with a laser rangefinder that we know of is using an off-the-shelf line scanner. Nobody has a true 3D scanner, although several teams have line scanners on tilt heads. It's quite possible to build a true 3D LIDAR depth measurement system. But it's hard to make money doing it, as the five companies that exited the field learned the hard way.
We hear talk of new vision algorithms, but no details yet. Stereo vision doesn't work well on dirt or sand; there aren't enough edges for the stereo algorithms to register the images properly. Optical flow doesn't work well for the same reason. If somebody can do good stereo from motion in this demanding environment, that will be an achievement.
Still, the Grand Challenge has done quite a bit to get autonomous vehicle work moving again. Just getting CMU off the dime (DARPA's real intent, we hear) was worth the whole effort.
If DARPA does this every year for the next decade, with a tougher course every time somebody wins, we will have battlefield robotics that works within ten years.