Clever DSP can make a wideband radio into (effectively) a narrowband one, but not vice versa.
This is somewhat true however there are severe limitations outside of the scope of the DSP itself. In digital radio design, if the IF bandwidth is wider then necessary, then no amount of DSP can recover the performance of the narrow IF because no current sampling technology yields enough dynamic range to allow rejection of worst case adjacent signals. This is doubly true if you want the necessary high sampling rate needed for q wide IF bandwidth. Presumably the goal would be sampling dynamic range sufficient to yield comparable performance in conditions where a narrowband receiver would suffer from blocking.
At a minimum, you would need some form of variable width IF filtering to extract the same performance of a simpler fixed bandwidth dedicated receiver. Variable width IF filter designs do exist although I have only seen them used to reject adjacent channel interference in designs that are already narrowband.
Crypto: 0 As received by: Transceiver Relay03 at Relay Language path: Cloudmark -> Twiskweline, SjK units [Cloudmark is a High Beyond trade language. Despite colloquial rendering, only core meaning is guaranteed.] From: Transcendent Bafflements Trading Union at Cloud Center Subject: Matter of life and death Summary: Arbitration Arts has fallen to Straumli Perversion via a Net attack. Use Middle Beyond relays till emergency passes! Key phrases: Net attack, scale interstellar warfare, Straumli Perversion Distribution: War Trackers Interest Group, Threats Interest Group, Homo Sapiens Interest Group Date: 61.12 days since the fall of Straumli Realm Text of message:
WARNING! The site identifying itself as Arbitration Arts is now controlled by the Staumli Perversion. The Arts' recent advertisement of communications services is a deadly trick. In fact we have good evidence that the Perversion used sapient Net packets to invade and disable the Arts' defenses. Large portions of the Arts now appear to be under direct control of the Straumli Power. Parts of the Arts that were not infected in the initial invasion have been destroyed by the converted portions: Fly-throughs show several stellifications.
What can be done: If during the last thousand seconds you have received any High-Beyond-protocol packets from "Arbitration Arts," discard them at once. If they have been processed, then the processing site and all locally netted sites must be physically destroyed at once. We realize that this means the destruction of solar systems, but consider the alternative. You are under Transcendent attack.
If you survive the initial peril (the next thirty hours or so), then there are obvious procedures that can give relative safety: Do not accept High Beyond protocol packets. At the very least, route all communications through Middle Beyond sites, with translation down to, and then up from, local trade languages.
For the longer term: It's obvious that an extraordinarily powerful Class Two Perversion has bloomed in our region of the galaxy. For the next thirteen years or so, all advanced civilizations near us will be in great danger.
If we can identify the background of the current perversion, we may discover its weakness and a feasible defense. Class Two Perversions all involve a deformed Power that creates symbiotic structures in the High Beyond - but there is an enormous variety of origins. Some are poorly-formed jokes told by Powers no longer on the scene. Others are weapons built by the newly transcendent, and never properly disarmed.
The immediate source of this danger is well-documented: a species recently up from the Middle Beyond, Homo sapiens, founded Straumli Realm. We are inclined to believe the theory proposed in messages [ . . . ], namely that Straumli researchers experimented with something in Shortcuts, and that the recipe was a self-booting evil from an earlier time. One possibility: Some loser from long ago planted how-to's on the Net (or in some lost archive) for the use of its own descendants. Thus, we are interested in any information related to Homo sapiens.
Niven's Known Space series only permitted hyperdrive at a constant 3 days per light year outside of the singularity generated by any large mass. With a more advanced hyperdrive, you could be anywhere in known space in 13 hours but not 12 hours because of the time spent in normal space around stars and planets. The singularity rule was later shown to be false and related to the missing dark matter. Ships that use hyperdrive within a singularity literally get eaten if they do not take precautions.
Pournelle's Empire of Man series only permitted FTL travel within stringent rules that had the effect of making interstellar travel resemble intercontinental travel by ocean going ship with the wartime possibilities including blockade, fleet in being, and mining. Any given star only had a finite and predictable number of points where ships could enter or leave hyperspace for neighboring stars. Some stars had no such points and were essentially isolated. Travel could take weeks or even months.
Many of the motherboard makers including Gigibyte and Asus have switched to using OSCON style solid electrolytic capacitors which do not suffer from the same problems that normal aluminum electrolytic capacitors do. While they like to brag about how noble this makes them, I suspect the real reason is that it just became more economical because of the increasingly stringent requirements for the processor's voltage regulator. In designs where the capacitors' equivalent series inductance and resistance have become fundamental limitations, the higher cost for OSCON style parts can cross over with the cost of using many more aluminum electrolytics.
Larry Niven's "Theory and Practice of Teleportation" goes into some of the fun ways such a system can cause some really large problems culminating with building a thruster capable of changing the earth's orbit. A more likely result though would be a short war until we get back to pre-portal technology.
Zoning screw-ups like you mention are not always caused by lack of diligence in verifying that the zoning is correct. The mistake can be deliberately caused by whoever ultimately controls zoning where there is an interest by either them or a third party to buy the now established successful business at a deep discount after which the zoning problem magically "fixes" itself.
Naw. The issue here is that George Bush cannot legally run for a third term and the machine's exploit configuration is no longer supported by the manufacturer so they need all new machines.
Car engines are already in the 1/4 ton range so add in a heavy transmission and the added battery weight is not that large an increase if any. The biggest worry as I see it is the possibility with some designs of a self destruct mode potentially worse then burning gasoline. Vehicles built on light truck frames have a nice large flat area which could be used to single stack an array of cells within a safety container with a minimum sacrifice in height.
For practical use, you must have an energy storage mechanism. Batteries currently can store electrical energy directly, but only in miniscule amounts. Not enough to be practical for a car... the energy density of batteries is too small, and the weight of batteries is too high.
I have to disagree here. I did the math a couple weeks ago and came up with about 7 pounds per mile for lithium based batteries currently used in cars and total battery weights between 1/2 ton and a ton. That is just feasible given that most of the weight of the internal combustion engine and transmission can be replaced however the current cost of the batteries is just too high to be economical. The large weight would also seem to make filling station battery replacement impractical short of using a fork lift.
Those patent encumbered NiMH cells might be viable but I have no idea how much they would cost. The best bet so far seems to be the development of a new manufacturing method for lithium-iron-phosphate or similar cells.
Just to add to this, the track eccentricity is larger then the track spacing and is not consistent between platters so using an embedded servo per head is a necessity. I remember reading about research into using a second stage of servo positioning by mounting a piezoelectric actuator closer to the head but no manufacturer has done this to the best of my knowledge. I would guess that adaptive DSP driven servo positioning algorithms were able to make up for the mechanical limitations of the voice coil and long arm.
I don't know about the Charlie card system, but the issue with many transit cards is that it's difficult or impossible for moving vehicles to always be able to check in with the network database to determine the value of an account.
It's just as well that people typically only get on and off buses which are stopped:) With trains there are often ticket operated barriers which never move.
It is a good thing nobody would think of using an RF jammer to temporarily disable the network link.
Not to mention, its what, 9600 baud? Better off with dial-up.
It is whatever the modulation and radio channel will support as long as the stations ID periodically and do not interfere with other stations. There are FCC restrictions which apply for the bands below 1.2 GHz but except for the 900 MHz and 440 MHz bands there is not really enough space to support anything really fast anyway. Common standards are usually implemented because of the availability of equipment that can be converted over (modem chips, etc.) but some commercially produced radios now implement a fully digital 128kbit/s mode in the 1.2 GHz band (along with digital voice) and faster custom systems exist. The 2.4 GHz band used for WiFi also overlaps the 2.4 GHz amateur band so equipment could be converted over and run under Part 97 rules but current manufacturers discourage this kind of use.
The FCC restrictions on commercial content and encryption are a larger impediment then data transmission speed limits and make this sort of application impractical anyway.
That is nothing. The place I was working at in Covina was doing a full scale dead load creep tests when the Whittier Narrows earthquake occured. The three story tall deal load machine failed the test . . .
What is interesting about this is that narrow band FM radios use the received signal strength (but not the AGC level because FM receivers do not use AGC) to drive the signal meter which may or may not be calibrated while the squelch is actually a function of the signal to noise ratio after demodulation is performed. For weak signal work quieting (signal to noise after FM demodulation) can be measured instead of received signal strength for greater sensitivity. The advantage other then being easier to do on an FM radio without tapping the IF signal before the demodulator is that only coherent signals are detected.
I am not surprised however that cell phone companies fudge the signal strength indicator in such a way as to make it useless for anything except marketing which is a real shame since real and objective numbers are available to the receiver.
He is saying that water in proximity to the conductors has a significantly different dielectric constant then air which changes the capacitance per unit length and impedance of all of the transmission lines and wiring. That by itself will cause RF circuits to fail since they will now be operating outside of their design range. Even if the capacitance and impedance changes do not cause failure, water is unusually lossy as a dielectric and this will raise the dissipation and lower the Q of everything affected. High frequency digital signals will also suffer from these problems.
Large valued ceramic capacitors while nice are rather expensive and are not as volumetrically efficient as tantalum electrolytics. Even worse, Z5U and similar dielectrics have a rather large capacitance to voltage and temperature coefficient. Maybe he was thinking of the newer OSCON type electrolytic capacitors? They have been around for at least ten years and are only now starting to show up in PC motherboards but they are neither ceramic nor tantalum based.
Tantalum capacitors have an odd failure mode associated with large inrush surge currents which can cause a rather spectacular crowbar like short circuit. They either have to be characterized for that type of service or appropriately derated.
Unless something like a sail is used in which case you are harvesting external wind energy, the added drag will always more then offset any gain in such a system.
At least for current hybrids, the lithium technology battery weight is about 7 pounds per mile so unless part of the plan includes a small hoist and full service, I doubt swapping battery packs is going to be very appealing.
Inverters designed for feeding excess power back into the grid not only must maintain phase lock but usually have provisions to continuously detect if the line has lost external power. If the utility power drops for any reason then the inverter disconnects and stops feeding power back into the line.
Slashdot Mirror
Clever DSP can make a wideband radio into (effectively) a narrowband one, but not vice versa.
This is somewhat true however there are severe limitations outside of the scope of the DSP itself. In digital radio design, if the IF bandwidth is wider then necessary, then no amount of DSP can recover the performance of the narrow IF because no current sampling technology yields enough dynamic range to allow rejection of worst case adjacent signals. This is doubly true if you want the necessary high sampling rate needed for q wide IF bandwidth. Presumably the goal would be sampling dynamic range sufficient to yield comparable performance in conditions where a narrowband receiver would suffer from blocking.
At a minimum, you would need some form of variable width IF filtering to extract the same performance of a simpler fixed bandwidth dedicated receiver. Variable width IF filter designs do exist although I have only seen them used to reject adjacent channel interference in designs that are already narrowband.
Crypto: 0
As received by: Transceiver Relay03 at Relay
Language path: Cloudmark -> Twiskweline, SjK units
[Cloudmark is a High Beyond trade language. Despite colloquial rendering, only core meaning is guaranteed.]
From: Transcendent Bafflements Trading Union at Cloud Center
Subject: Matter of life and death
Summary: Arbitration Arts has fallen to Straumli Perversion via a Net attack. Use Middle Beyond relays till emergency passes!
Key phrases: Net attack, scale interstellar warfare, Straumli Perversion
Distribution: War Trackers Interest Group, Threats Interest Group, Homo Sapiens Interest Group
Date: 61.12 days since the fall of Straumli Realm
Text of message:
WARNING! The site identifying itself as Arbitration Arts is now controlled by the Staumli Perversion. The Arts' recent advertisement of communications services is a deadly trick. In fact we have good evidence that the Perversion used sapient Net packets to invade and disable the Arts' defenses. Large portions of the Arts now appear to be under direct control of the Straumli Power. Parts of the Arts that were not infected in the initial invasion have been destroyed by the converted portions: Fly-throughs show several stellifications.
What can be done: If during the last thousand seconds you have received any High-Beyond-protocol packets from "Arbitration Arts," discard them at once. If they have been processed, then the processing site and all locally netted sites must be physically destroyed at once. We realize that this means the destruction of solar systems, but consider the alternative. You are under Transcendent attack.
If you survive the initial peril (the next thirty hours or so), then there are obvious procedures that can give relative safety: Do not accept High Beyond protocol packets. At the very least, route all communications through Middle Beyond sites, with translation down to, and then up from, local trade languages.
For the longer term: It's obvious that an extraordinarily powerful Class Two Perversion has bloomed in our region of the galaxy. For the next thirteen years or so, all advanced civilizations near us will be in great danger.
If we can identify the background of the current perversion, we may discover its weakness and a feasible defense. Class Two Perversions all involve a deformed Power that creates symbiotic structures in the High Beyond - but there is an enormous variety of origins. Some are poorly-formed jokes told by Powers no longer on the scene. Others are weapons built by the newly transcendent, and never properly disarmed.
The immediate source of this danger is well-documented: a species recently up from the Middle Beyond, Homo sapiens, founded Straumli Realm. We are inclined to believe the theory proposed in messages [ . . . ], namely that Straumli researchers experimented with something in Shortcuts, and that the recipe was a self-booting evil from an earlier time. One possibility: Some loser from long ago planted how-to's on the Net (or in some lost archive) for the use of its own descendants. Thus, we are interested in any information related to Homo sapiens.
Only if you managed to compress the whole earth down to a 8.88 millimeter radius. The force of gravity at the center of a uniform sphere is zero.
You can't possibly be worried about something that is going to happen 20 thousand years from now.
Oh Yeah? What about Photoshop?
Niven's Known Space series only permitted hyperdrive at a constant 3 days per light year outside of the singularity generated by any large mass. With a more advanced hyperdrive, you could be anywhere in known space in 13 hours but not 12 hours because of the time spent in normal space around stars and planets. The singularity rule was later shown to be false and related to the missing dark matter. Ships that use hyperdrive within a singularity literally get eaten if they do not take precautions.
Pournelle's Empire of Man series only permitted FTL travel within stringent rules that had the effect of making interstellar travel resemble intercontinental travel by ocean going ship with the wartime possibilities including blockade, fleet in being, and mining. Any given star only had a finite and predictable number of points where ships could enter or leave hyperspace for neighboring stars. Some stars had no such points and were essentially isolated. Travel could take weeks or even months.
http://en.wikipedia.org/wiki/Alderson_drive
I miss the quiet "shook-shook-shook" of 8" and 5 1/4" floppy disk drives.
Many of the motherboard makers including Gigibyte and Asus have switched to using OSCON style solid electrolytic capacitors which do not suffer from the same problems that normal aluminum electrolytic capacitors do. While they like to brag about how noble this makes them, I suspect the real reason is that it just became more economical because of the increasingly stringent requirements for the processor's voltage regulator. In designs where the capacitors' equivalent series inductance and resistance have become fundamental limitations, the higher cost for OSCON style parts can cross over with the cost of using many more aluminum electrolytics.
Larry Niven's "Theory and Practice of Teleportation" goes into some of the fun ways such a system can cause some really large problems culminating with building a thruster capable of changing the earth's orbit. A more likely result though would be a short war until we get back to pre-portal technology.
Zoning screw-ups like you mention are not always caused by lack of diligence in verifying that the zoning is correct. The mistake can be deliberately caused by whoever ultimately controls zoning where there is an interest by either them or a third party to buy the now established successful business at a deep discount after which the zoning problem magically "fixes" itself.
Naw. The issue here is that George Bush cannot legally run for a third term and the machine's exploit configuration is no longer supported by the manufacturer so they need all new machines.
Car engines are already in the 1/4 ton range so add in a heavy transmission and the added battery weight is not that large an increase if any. The biggest worry as I see it is the possibility with some designs of a self destruct mode potentially worse then burning gasoline. Vehicles built on light truck frames have a nice large flat area which could be used to single stack an array of cells within a safety container with a minimum sacrifice in height.
I have to disagree here. I did the math a couple weeks ago and came up with about 7 pounds per mile for lithium based batteries currently used in cars and total battery weights between 1/2 ton and a ton. That is just feasible given that most of the weight of the internal combustion engine and transmission can be replaced however the current cost of the batteries is just too high to be economical. The large weight would also seem to make filling station battery replacement impractical short of using a fork lift.
Those patent encumbered NiMH cells might be viable but I have no idea how much they would cost. The best bet so far seems to be the development of a new manufacturing method for lithium-iron-phosphate or similar cells.
I agree completely. SPICE printouts make an excellent cover for the bottom of my bird cage.
Just to add to this, the track eccentricity is larger then the track spacing and is not consistent between platters so using an embedded servo per head is a necessity. I remember reading about research into using a second stage of servo positioning by mounting a piezoelectric actuator closer to the head but no manufacturer has done this to the best of my knowledge. I would guess that adaptive DSP driven servo positioning algorithms were able to make up for the mechanical limitations of the voice coil and long arm.
I don't know about the Charlie card system, but the issue with many transit cards is that it's difficult or impossible for moving vehicles to always be able to check in with the network database to determine the value of an account.
It's just as well that people typically only get on and off buses which are stopped :) With trains there are often ticket operated barriers which never move.
It is a good thing nobody would think of using an RF jammer to temporarily disable the network link.
Not to mention, its what, 9600 baud? Better off with dial-up.
It is whatever the modulation and radio channel will support as long as the stations ID periodically and do not interfere with other stations. There are FCC restrictions which apply for the bands below 1.2 GHz but except for the 900 MHz and 440 MHz bands there is not really enough space to support anything really fast anyway. Common standards are usually implemented because of the availability of equipment that can be converted over (modem chips, etc.) but some commercially produced radios now implement a fully digital 128kbit/s mode in the 1.2 GHz band (along with digital voice) and faster custom systems exist. The 2.4 GHz band used for WiFi also overlaps the 2.4 GHz amateur band so equipment could be converted over and run under Part 97 rules but current manufacturers discourage this kind of use.
The FCC restrictions on commercial content and encryption are a larger impediment then data transmission speed limits and make this sort of application impractical anyway.
That is nothing. The place I was working at in Covina was doing a full scale dead load creep tests when the Whittier Narrows earthquake occured. The three story tall deal load machine failed the test . . .
What is interesting about this is that narrow band FM radios use the received signal strength (but not the AGC level because FM receivers do not use AGC) to drive the signal meter which may or may not be calibrated while the squelch is actually a function of the signal to noise ratio after demodulation is performed. For weak signal work quieting (signal to noise after FM demodulation) can be measured instead of received signal strength for greater sensitivity. The advantage other then being easier to do on an FM radio without tapping the IF signal before the demodulator is that only coherent signals are detected.
I am not surprised however that cell phone companies fudge the signal strength indicator in such a way as to make it useless for anything except marketing which is a real shame since real and objective numbers are available to the receiver.
He is saying that water in proximity to the conductors has a significantly different dielectric constant then air which changes the capacitance per unit length and impedance of all of the transmission lines and wiring. That by itself will cause RF circuits to fail since they will now be operating outside of their design range. Even if the capacitance and impedance changes do not cause failure, water is unusually lossy as a dielectric and this will raise the dissipation and lower the Q of everything affected. High frequency digital signals will also suffer from these problems.
I am not sure what he was talking about either.
Large valued ceramic capacitors while nice are rather expensive and are not as volumetrically efficient as tantalum electrolytics. Even worse, Z5U and similar dielectrics have a rather large capacitance to voltage and temperature coefficient. Maybe he was thinking of the newer OSCON type electrolytic capacitors? They have been around for at least ten years and are only now starting to show up in PC motherboards but they are neither ceramic nor tantalum based.
Tantalum capacitors have an odd failure mode associated with large inrush surge currents which can cause a rather spectacular crowbar like short circuit. They either have to be characterized for that type of service or appropriately derated.
Harry Turtledove's "The Road not Taken" comes to mind:
http://en.wikipedia.org/wiki/The_Road_Not_Taken_(short_story)
Unless something like a sail is used in which case you are harvesting external wind energy, the added drag will always more then offset any gain in such a system.
At least for current hybrids, the lithium technology battery weight is about 7 pounds per mile so unless part of the plan includes a small hoist and full service, I doubt swapping battery packs is going to be very appealing.
Inverters designed for feeding excess power back into the grid not only must maintain phase lock but usually have provisions to continuously detect if the line has lost external power. If the utility power drops for any reason then the inverter disconnects and stops feeding power back into the line.