In short, technically, there is no such thing as an "active antenna".
I think the general text book answer is that phased-array antennas with an LNA in each element is considered `active', as opposed to a `passive' system which couples, phase corrects, and combines before amplification.
Please don't yell at me if I'm wrong...:-)
By reading this post you have accepted the terms of my license agreement. Please send check or money order to...
You're right. I used to work on the AEGIS weapon system's SPY radar. Once a projectile is completely ballistic it's trajectory is easily predictable. It's more difficult to determine the trajectory of a missile that is still burning fuel. In this case the radar must determine the type of missile.
In AEGIS we would fire an interceptor missile at a threat. The interceptor has mid-course guidance capability with a window of opportunity, so you can't fire the thing in the wrong direction and expect it to still hit the target. Therefore, your predictions must be highly accurate, accounting for wind, earth coriolis (the earth is moving underneath the projectiles), non-constant heterogenous gravity (weaker as the projectiles move further away from the earth, not in a straight line, and different for different parts of the earth).
The equation for filtering in this case is quite a mess. I'd imagine predicting for a laser is much easier because your interceptor is much faster, more stearable, etc.
If you're really interested in how it works, get a book on the Kalman filter. By the way, this technique is also useful in enemy AI development for games!
1280x1024x1024 in true color is 5 gigabytes! Double that with z-page swapping (doing the work in a second section of memory, then, when the raster scan is resetting, move the contents into video memory). Finally AGP 4x has a peak transfer rate of 1 GB/s. Well, I guess by the time this tech comes to market, the rest of the hardware will be up to speed.
Under pressure from their citizens, governments around the world are increasingly abandoning the hands-off attitude they initially had toward the Internet.
I mean the part about the citizens pressuring the government for a hands-on policy.
I guess if you spend 20 years studying one topic, it inevitably becomes the answer to the universe. From the ANKOS web site
And in fact what I've discovered is that some of the very simplest imaginable computer programs can do things as complex as anything in our whole universe.
I think Feynman and Hawking would disagree. Quantum mechanics is proving classical computers can't exactly simulate even the tiniest building block, the atom.
things in our universe somehow follow rules that can be represented by traditional mathematical equations. The basic idea that underlies A New Kind of Science is that that's much too restrictive, and that in fact one should consider the vastly more general kinds of rules that can be embodied, for example, in computer programs.
Anything that can be done in a computer program can be expressed mathematically.
Point being, it is not the answer to everything Wolfram seems to tout it to be. And I have not even seen the book. But I'm sure it's an exhaustive study of a fascinating subject.
Phone number on CC bill
on
Disconnecting
·
· Score: 1
> So at the least I propose that ISPs be required to send monthly bills, listing numbers to call or websites to visit...
I like it when monthly charges on your credit card bill come with a phone number to call for customer service. My old ISP did this, although I don't remember the name (some Mom and Pop ISP). I thought, "What a great idea! The phone number is exactly where I need it, right next to the charge." I'd like to see more of this.
I read this book by Hawking some time ago; I make no claims about understanding it. He mentioned several logical possibilities, which should summarize what everyone else has been saying in spurious posts...
1. A beginning with no end. Our universe began from the big bang and, if the gravitational pull of the center is not large enough to overcome the momentum of the explosion, will continue to expand though infinity. 2. A beginning with an end. The gravitational pull of the center can overcome the momentum of the explosion, resulting in a big crunch.
These two only describe our observable universe. Time begins with each explosion and ends with each contraction. If the gravitational pull, which grows as the universal spheroid becomes more massive, can pull the mass smaller than infinitesimal (mathematically speaking, I guess) then a bounce occurs, resulting in another explosion.
3. If the ratio of energy/mass remains constant with each explosion, then THE universe (not OUR universe) continues from -infinity to +infinity, as the article states. 4. If the ratio increases every time, the explosion will eventually provide enough momentum to overcome the pull of gravity (case 2). We may be in this state now, or we may not. 5. If the ratio decreases every time, then eventually the universe will be pulled into a point, with just enough energy to keep it there. Our universe may have this finite end, or it may not.
Ad-Aware is a free program designed to scan a PC for ad-supported software components or "spyware" and to remove them.
It seems as though Ad-Aware is doing the same thing (i.e. removing software). Can it be legal for them because they are removing something we don't want?
I have a really great.sig, but I'm not going to give it to you.
That's the earth's equatorial radius (6378137 m) The equatorial radius of the moon is 1738.1 km.
The surface area of that sphere(oid) is 3.796e7 km^2, and one percent is 3.796e5 km^2.
Now if we place our cells in a cluster, they will only receive 1% of the radiation, 50% of the time (probably less, because the cells will not be orthogonal to the sun's wave front), so let's multiply by 2 = 7.593e5 km^2. For reference, that's about 2% of the surface area of the moon.
...perhaps Gateway is counting on increased sales as the lone (or at least the loudest/richest) defender of on-line 'justice'. I assume general public opinion is, 'free Internet is good, gov't intervention is bad'. Say that to most lamen and their response will probably be 'hell yea!'. Gateway can increase it's public image (read sales) by jumping on the bandwagon.
But how bad can it be? By rallying behind Gateway (and all their money) are we going to put them into a position to corner the market? Do we really think they have a hidden agenda? I don't think any of their history has shown that they desire to 'control' the sharing of information.
The premise is that, once Hollings' bill gets stopped, presumably because of Gateway's influence, the community turns to Gateway and says, "Well, you wanted to stop this, now what?" Then Gateway, having been given the authority, begins to place its own restrictions and controls on Internet sharing. I don't think that's going to happen.
They do want to support free Internet because that's good for sales, and also good for us. Everybody wins! So I say...
A toilet greets Homer in a typical Japanese accent, "I am happy to receive your waste." After he's done it plays a happy tune and squirts colored streams of water like a fountain.
I have used Express PCB twice and have been happy with their quality and response time. They have a free CAD PCB design tool available for download. This is great for small, do-it-yourself projects requiring better manufacturing than Radio Shack kits can provide. They create two-sided boards complete with vias.
What other services are available?
I have a really great quote, but I'm not going to tell you. -- me
Slashdot Mirror
Check out the statistics page for the site. What's that big spike around the 8th of November? (insert maniacal laugh)
By reading this post you have agreed to my EULA. Please send check or money order to...
In short, technically, there is no such thing as an "active antenna".
:-)
I think the general text book answer is that phased-array antennas with an LNA in each element is considered `active', as opposed to a `passive' system which couples, phase corrects, and combines before amplification.
Please don't yell at me if I'm wrong...
By reading this post you have accepted the terms of my license agreement. Please send check or money order to...
You're right. I used to work on the AEGIS weapon system's SPY radar. Once a projectile is completely ballistic it's trajectory is easily predictable. It's more difficult to determine the trajectory of a missile that is still burning fuel. In this case the radar must determine the type of missile.
In AEGIS we would fire an interceptor missile at a threat. The interceptor has mid-course guidance capability with a window of opportunity, so you can't fire the thing in the wrong direction and expect it to still hit the target. Therefore, your predictions must be highly accurate, accounting for wind, earth coriolis (the earth is moving underneath the projectiles), non-constant heterogenous gravity (weaker as the projectiles move further away from the earth, not in a straight line, and different for different parts of the earth).
The equation for filtering in this case is quite a mess. I'd imagine predicting for a laser is much easier because your interceptor is much faster, more stearable, etc.
If you're really interested in how it works, get a book on the Kalman filter. By the way, this technique is also useful in enemy AI development for games!
1280x1024x1024 in true color is 5 gigabytes! Double that with z-page swapping (doing the work in a second section of memory, then, when the raster scan is resetting, move the contents into video memory). Finally AGP 4x has a peak transfer rate of 1 GB/s. Well, I guess by the time this tech comes to market, the rest of the hardware will be up to speed.
.sig
Fun!
This is a
From the article, the results should be available in two months, not two weeks as supposed by /.
.sig, but I'm not going to give it to you.
I have a really great
Is this true?
Under pressure from their citizens, governments around the world are increasingly abandoning the hands-off attitude they initially had toward the Internet.
I mean the part about the citizens pressuring the government for a hands-on policy.
Who are all those beautiful people in the SourceForge ad? Who are they trying to fool?
I guess if you spend 20 years studying one topic, it inevitably becomes the answer to the universe. From the ANKOS web site
And in fact what I've discovered is that some of the very simplest imaginable computer programs can do things as complex as anything in our whole universe.
I think Feynman and Hawking would disagree. Quantum mechanics is proving classical computers can't exactly simulate even the tiniest building block, the atom.
things in our universe somehow follow rules that can be represented by traditional mathematical equations. The basic idea that underlies A New Kind of Science is that that's much too restrictive, and that in fact one should consider the vastly more general kinds of rules that can be embodied, for example, in computer programs.
Anything that can be done in a computer program can be expressed mathematically.
Point being, it is not the answer to everything Wolfram seems to tout it to be. And I have not even seen the book. But I'm sure it's an exhaustive study of a fascinating subject.
> So at the least I propose that ISPs be required to send monthly bills, listing numbers to call or websites to visit...
I like it when monthly charges on your credit card bill come with a phone number to call for customer service. My old ISP did this, although I don't remember the name (some Mom and Pop ISP). I thought, "What a great idea! The phone number is exactly where I need it, right next to the charge." I'd like to see more of this.
3G needs to find a different killer app.
.sig, but I'm not going to share it with you.
They already have...it's called Gnutella
I have a really great
I read this book by Hawking some time ago; I make no claims about understanding it. He mentioned several logical possibilities, which should summarize what everyone else has been saying in spurious posts...
.sig you've ever seen.
1. A beginning with no end. Our universe began from the big bang and, if the gravitational pull of the center is not large enough to overcome the momentum of the explosion, will continue to expand though infinity.
2. A beginning with an end. The gravitational pull of the center can overcome the momentum of the explosion, resulting in a big crunch.
These two only describe our observable universe. Time begins with each explosion and ends with each contraction. If the gravitational pull, which grows as the universal spheroid becomes more massive, can pull the mass smaller than infinitesimal (mathematically speaking, I guess) then a bounce occurs, resulting in another explosion.
3. If the ratio of energy/mass remains constant with each explosion, then THE universe (not OUR universe) continues from -infinity to +infinity, as the article states.
4. If the ratio increases every time, the explosion will eventually provide enough momentum to overcome the pull of gravity (case 2). We may be in this state now, or we may not.
5. If the ratio decreases every time, then eventually the universe will be pulled into a point, with just enough energy to keep it there. Our universe may have this finite end, or it may not.
This is the greatest
From the article:
.sig, but I'm not going to give it to you.
Ad-Aware is a free program designed to scan a PC for ad-supported software components or "spyware" and to remove them.
It seems as though Ad-Aware is doing the same thing (i.e. removing software). Can it be legal for them because they are removing something we don't want?
I have a really great
Crappy geocities... Is there someplace else I can put it?
Here is a PDF version.
Boy could I use the Karma!
And if we use Bad Math logic (%20), that gives a surface area of 7.593e6, almost the size of the U.S.!
.sig you have ever seen.
This is the greatest
Radius of the moon [nasa.gov]: 6378.1 km
That's the earth's equatorial radius (6378137 m)
The equatorial radius of the moon is 1738.1 km.
The surface area of that sphere(oid) is 3.796e7 km^2, and one percent is 3.796e5 km^2.
Now if we place our cells in a cluster, they will only receive 1% of the radiation, 50% of the time (probably less, because the cells will not be orthogonal to the sun's wave front), so let's multiply by 2 = 7.593e5 km^2. For reference, that's about 2% of the surface area of the moon.
All your karma are belong to us (me).
...perhaps Gateway is counting on increased sales as the lone (or at least the loudest/richest) defender of on-line 'justice'. I assume general public opinion is, 'free Internet is good, gov't intervention is bad'. Say that to most lamen and their response will probably be 'hell yea!'. Gateway can increase it's public image (read sales) by jumping on the bandwagon.
But how bad can it be? By rallying behind Gateway (and all their money) are we going to put them into a position to corner the market? Do we really think they have a hidden agenda? I don't think any of their history has shown that they desire to 'control' the sharing of information.
The premise is that, once Hollings' bill gets stopped, presumably because of Gateway's influence, the community turns to Gateway and says, "Well, you wanted to stop this, now what?" Then Gateway, having been given the authority, begins to place its own restrictions and controls on Internet sharing. I don't think that's going to happen.
They do want to support free Internet because that's good for sales, and also good for us. Everybody wins! So I say...
Yea Gateway!
A toilet greets Homer in a typical Japanese accent, "I am happy to receive your waste." After he's done it plays a happy tune and squirts colored streams of water like a fountain.
I have used Express PCB twice and have been happy with their quality and response time. They have a free CAD PCB design tool available for download. This is great for small, do-it-yourself projects requiring better manufacturing than Radio Shack kits can provide. They create two-sided boards complete with vias.
What other services are available?
I have a really great quote, but I'm not going to tell you. -- me