You don't GET PAID driving down a toll road one way, do you?:-)
No, but you usually don't have to pay to get off the road either. The complaint here is that each packet is charged twice -- once to the ingress network, and once to the egress network.
Stealing any one credit card doesn't deserve a huge penalty (say, 15 minutes in jail?), but if you multiply that by 5 million credit cards, I'd say that 142 years sounds about right.
UDP isn't effected; but UDP based protocols might be -- it depends upon the protocol. Most people who write code to use UDP don't have a clue what they're doing, so it wouldn't surprise me if their code would break completely in the presence of multipath effects.
Sort of. TCP/IP does indeed work in the presence of multipath effects... but it works very slowly. To be specific, any time a packet arrives more than three packets out of sequence, the network is considered to be "congested" and the data rate is reduced.
but it's a result of stupid bureaucrats nonetheless.
Graduate students in the computing lab at Oxford University have swipe card access to the building 24 hours a day. University regulations stipulate that anyone who could be working alone must take a first aid course; consequently, all graduate students in computer science are required to attend this course.
Personally, I find the idea of satellites being used for the "last mile" just a bit scary. "Last 100 miles", perhaps, but I wouldn't want to be underneath a satellite which was providing "last mile" connectivity.
What I'm more worried about is that US military radar evidently is so sensitive and fragile that even a low powered signal in the 5GHz range can knock it out - I honestly thought their stuff was designed to handle military grade ECM but it sounds like they can't even handle consumer grade wifi equipment.
It's all a question of power. In friendly territory (ie, in the middle of a US city) they probably don't want to use too much power, just for the sake of avoiding complaints; but they'll still want to have functioning radar for navigational purposes. In a hostile environment, they can increase the power without anyone complaining.
We're not that good at building implants yet. The human body is a rather hostile environment, really; bone has the advantage that it is continuously repaired.
(quoting an AC): NTP is a hierarchy - tier 1, tier 2, etc. This don't sound like one.
NTP is organized as a hierarchy because there is a "true" time which it attempts to track. Take away the atomic clocks, and NTP would collapse into a hierarchy-less system which nevertheless converges to agreement about some sort of "time".
Based on the (limited) details available, I'd say it sounds like they've just reinvented NTP -- except they've done it poorly, and without any security.
Just as people have come to expect high grades, they've come to expect degrees. The UK government has decided that they want 50% of students to attend university... the only way to accomplish this is to hand out degrees for attendance.
A few decades ago, a typical question on a university entrance exam for someone reading science (chemistry, physics, math, whatever) would involve solving a system of partial differential equations. How many students now could solve those problems before their third year?
People need to wake up and find a new method of evaluating their educational systems. High grades do not make a student intelligent. A university degree does not make a student intelligent. Telling universities that they must increase their student intake makes the overall education of the populace worse, not better.
Quote from the 4.6 (non)release story: Murray Stokely writes "We have gone over this for the past 2 releases now. I thought I had made it clear that you were not to publish information about FreeBSD being released until you saw a signed PGP message from one of the release engineers. Are you trying to help the spread of trojanned copies of FreeBSD? The release is not ready yet, and will not be until the front page of FreeBSD.org is updated and a PGP signed announcement message is posted to announce@FreeBSD.org."
Unless the rules have changed, slashdot screwed up again.
All prime factors of 2^p-1 are of the form 2kp+1 for some k. If we're looking for a factor, the obvious place to start is with k=1, which tells us that we should look at 2*239+1 = 479.
Now, 2^7 = 128, so 2^14 mod 479 = 98, 2^29 mod 479 = 2*98^2 = 48 2^59 mod 479 = 2*48^2 = 297 2^119 mod 479 = 2*297^2 = 146 2^239 mod 479 = 2*146^2 = 1
I said *about* 250 gigabits per cm^2. 8% error is close enough here, especially given that there would be layers of ECC and formatting before the user sees anything.
The 239th Mersenne number, 2^239 - 1, is known composite, but no factors are known.
Not true. It wasn't even true when it was written: It takes only about a minute with pencil and paper to discover that 2^239 - 1 is a multiple of 479.
Hard to understand?
on
Hacker's Delight
·
· Score: 5, Interesting
use of these tricks does violate the Keep It Simple, Clock Cycles Are Cheap And Someone May Have To Understand Your Code philosophy
In some cases, this may be true, but not always. If you want to increment a multiple-precision value, the textbook method is
int i, carry=1;
for(i=0;icarry+=x[i]; x[i]=carry; carr y/=radix; };
while the "cute trick" method is
int i=0;
while(++x[i]==0) i++;
The textbook method takes a while to recognize, just because it's very similar to many other loops; but the second is distinctive and can be recognized immediately. If I'm maintaining someon else's code, I'd much prefer to see the second.
Slashdot Mirror
You don't GET PAID driving down a toll road one way, do you? :-)
No, but you usually don't have to pay to get off the road either. The complaint here is that each packet is charged twice -- once to the ingress network, and once to the egress network.
Yes.
Stealing any one credit card doesn't deserve a huge penalty (say, 15 minutes in jail?), but if you multiply that by 5 million credit cards, I'd say that 142 years sounds about right.
echo /dev/urandom /dev/ttyS0 /dev/urandom /dev/ttyS0
How about,
}
while(reading_slashdot){++nerdiness;--social_life
Personally, I prefer
for(;reading_slashdot;++nerdiness) --social_life;
This software does NOT write to your boot sector. It writes to sector 33 on the track which contiains the boot sector.
This is certainly a Bad Thing, but not nearly as bad as writing to the boot sector would be.
UDP isn't effected; but UDP based protocols might be -- it depends upon the protocol. Most people who write code to use UDP don't have a clue what they're doing, so it wouldn't surprise me if their code would break completely in the presence of multipath effects.
TCP/IP is designed for multiple routes
Sort of. TCP/IP does indeed work in the presence of multipath effects... but it works very slowly. To be specific, any time a packet arrives more than three packets out of sequence, the network is considered to be "congested" and the data rate is reduced.
but it's a result of stupid bureaucrats nonetheless.
Graduate students in the computing lab at Oxford University have swipe card access to the building 24 hours a day. University regulations stipulate that anyone who could be working alone must take a first aid course; consequently, all graduate students in computer science are required to attend this course.
The first aid course in question is basic CPR.
What would you have gotten? Poorly written essays?
How about the network administrator's root password?
When I was in high school, I had to write a TSR to do this. You kids have things easy these days...
Personally, I find the idea of satellites being used for the "last mile" just a bit scary. "Last 100 miles", perhaps, but I wouldn't want to be underneath a satellite which was providing "last mile" connectivity.
What I'm more worried about is that US military radar evidently is so sensitive and fragile that even a low powered signal in the 5GHz range can knock it out - I honestly thought their stuff was designed to handle military grade ECM but it sounds like they can't even handle consumer grade wifi equipment.
It's all a question of power. In friendly territory (ie, in the middle of a US city) they probably don't want to use too much power, just for the sake of avoiding complaints; but they'll still want to have functioning radar for navigational purposes. In a hostile environment, they can increase the power without anyone complaining.
We're not that good at building implants yet. The human body is a rather hostile environment, really; bone has the advantage that it is continuously repaired.
(quoting an AC):
NTP is a hierarchy - tier 1, tier 2, etc.
This don't sound like one.
NTP is organized as a hierarchy because there is a "true" time which it attempts to track. Take away the atomic clocks, and NTP would collapse into a hierarchy-less system which nevertheless converges to agreement about some sort of "time".
Based on the (limited) details available, I'd say it sounds like they've just reinvented NTP -- except they've done it poorly, and without any security.
Any bright light will allow you to see the bones in your hand -- you don't need x-rays. We're really not nearly as opaque as we think we are.
You evidently didn't RTFA carefully enough -- the subject line ("max simultaneous TCP connections") should have been a giveaway.
Just as people have come to expect high grades, they've come to expect degrees. The UK government has decided that they want 50% of students to attend university... the only way to accomplish this is to hand out degrees for attendance.
A few decades ago, a typical question on a university entrance exam for someone reading science (chemistry, physics, math, whatever) would involve solving a system of partial differential equations. How many students now could solve those problems before their third year?
People need to wake up and find a new method of evaluating their educational systems. High grades do not make a student intelligent. A university degree does not make a student intelligent. Telling universities that they must increase their student intake makes the overall education of the populace worse, not better.
Remember, the music industry is loosely associated with the war industry
Indeed. Very loosely.
Most computer hardware companies have links to the US nuclear weapons programme. Should we boycott them as well?
Quote from the 4.6 (non)release story:
Murray Stokely writes "We have gone over this for the past 2 releases now. I thought I had made it clear that you were not to publish information about FreeBSD being released until you saw a signed PGP message from one of the release engineers. Are you trying to help the spread of trojanned copies of FreeBSD? The release is not ready yet, and will not be until the front page of FreeBSD.org is updated and a PGP signed announcement message is posted to announce@FreeBSD.org."
Unless the rules have changed, slashdot screwed up again.
If you have a minute, then, how does that work?
All prime factors of 2^p-1 are of the form 2kp+1 for some k. If we're looking for a factor, the obvious place to start is with k=1, which tells us that we should look at 2*239+1 = 479.
Now, 2^7 = 128, so
2^14 mod 479 = 98,
2^29 mod 479 = 2*98^2 = 48
2^59 mod 479 = 2*48^2 = 297
2^119 mod 479 = 2*297^2 = 146
2^239 mod 479 = 2*146^2 = 1
so 2^239-1 is a multiple of 479.
I said *about* 250 gigabits per cm^2. 8% error is close enough here, especially given that there would be layers of ECC and formatting before the user sees anything.
The 239th Mersenne number, 2^239 - 1, is known composite, but no factors are known.
Not true. It wasn't even true when it was written: It takes only about a minute with pencil and paper to discover that 2^239 - 1 is a multiple of 479.
In some cases, this may be true, but not always. If you want to increment a multiple-precision value, the textbook method is while the "cute trick" method is
The textbook method takes a while to recognize, just because it's very similar to many other loops; but the second is distinctive and can be recognized immediately. If I'm maintaining someon else's code, I'd much prefer to see the second.
For those of you using sane units, this is about 250 gigabits per cm^2.