In conventional terms, when a one is written to disk the media records a one, and when a zero is written the media records a zero. However the actual effect is closer
to obtaining a 0.95 when a zero is overwritten with a one, and a 1.05 when a one is overwritten with a one. Normal disk circuitry is set up so that both these values are
read as ones, but using specialised circuitry it is possible to work out what previous "layers" contained. The recovery of at least one or two layers of overwritten data
isn't too hard to perform by reading the signal from the analog head electronics with a high-quality digital sampling oscilloscope, downloading the sampled waveform to
a PC, and analysing it in software to recover the previously recorded signal. What the software does is generate an "ideal" read signal and subtract it from what was
actually read, leaving as the difference the remnant of the previous signal. Since the analog circuitry in a commercial hard drive is nowhere near the quality of the
circuitry in the oscilloscope used to sample the signal, the ability exists to recover a lot of extra information which isn't exploited by the hard drive electronics (although
with newer channel coding techniques such as PRML (explained further on) which require extensive amounts of signal processing, the use of simple tools such as an
oscilloscope to directly recover the data is no longer possible).
So, in conclusion - Sorry, can't be done without modifying the electronics in the drive. That might be a challenge to the drive manufacturers though... how to get your density doubled by purposefully use the overwrite and read both the previous and current data! Kind of the same idea as the two bits per cell technology used by flash memory manufacturers...
In Canada, if you send a letter to your MP, its free! I imagine in the states the same goes for your elected officials. So, if you really want things to change, bundle up all your junk mail and put a sticker:
To Such and Such, Member of Parliament
Parliament Hill, Ottawa
And away it goes!
There was an organized campaign a couple of years ago where Thousands of people did this and it ended up clogging up the mail room over at Canada's headquarters for a while. I don't remember if anything came out of this or not.
How much processing power do you need to process a few sensors and drive a couple wheels? $200 bucks worth of palm? Uhh... how about $4 bucks worth of microcontroller like a nice 16C64 from PIC Microship microcontroller? Enough to make a hardware guy cry! Onboard RAM, ROM, EEPROM.... mmmmm..... timers and interrupt vectors.... 20mA drive current.... whoo-hooo! Just need a few H-Bridges and a couple infrared leds and detectors. You wanted to know what to do with those old 5 1/4" drives... its time to get out those irons and solder suckers!
I suppose this kit is nice for those software types that don't like to touch hardware, but what fun is that?
If you REAALY dont want to challenge yourself, and don't want to touch hardware, I would think a nice Lego mindstorms kit would be better suited and more flexable. Reconfigurable, and you can always buy more motors and sensors.
A freaking GUI for a robot? And thats a selling feature? Who needs a GUI anyways;-)
How bout we have a new slashdot interview with Hemos to find out what is up with all the double postings lately;-) (And other assorted questions... that tend to be repeated over and over...)
I'd like to see a interview for the Slashdot team ! Post your questions below....
Question 1. What's going on with the moderation scheme here at Slashdot? Anybody working on changes/improvements?
I found it refreshing to see some decent software testing going on. Why does it take two yahoos to find out that there are serious rendering differences in browsers? I guess this is another result of the 'browser wars'. Freaking guys, get together and come up with a standard!
If only people TESTED their software. Jeeze, you think somebody at Micro$oft would have at least found that silly rendering bug.
I guess that's the problem when you aren't working from a spec (just make it up as you go....) Is there a spec stating how colours are to be rendered mathematically? Ie round up or round down in these cases?
It seems logical to me that in order to solve some of these ambiguious choices there has to be a spec.
I guess the only chance is that we get a couple of motivated geeks that see the problem, and start chomping off bits and pieces of it.
I've actually got some great news - because of this forum I've recieved a couple emails which have lead to the formation of a project on SourceForge - called Open Schoolhouse.
We're going to attempt to do what you call tough - the open source development of a School administration project.
We're going to start by developing a core database - then add on modules that can provide the different functions that various schools need! We're going to start with the report card generation stuff and go from there.
Check us out on SourceForge and if you feel you can contribute -anyone can help us- than please do! I look forward to talking to you all there!
I'm the guy that posed the question. Ok, here's the deal. I'm running various linux based services which basically run the school. Internet, file access, printing, backups - all the goodies are powered by open source software.
Our poor admin who runs the office though is being run ragged during the school year trying to keep various lists up to date, and producing dumb documents - like membership lists, student health records for when students go on class trips, transcripts - stuff like that. This is all being done semi-manually (spreadsheets and wordprocessing).
A database powered suite which provided admin type functions for a school - something that is flexable, extendable, and most importantly OPEN - so we can fix that reportcard when the format needs to change. That's the tool I'm looking for.
Maplewood offers a nice product - but it's closed source and its price would break our budget.
I've done the grunt work searching on freshmeat to no avail. I'll check out a few of the links posted above to see if anybody is working on anything now, otherwise I just might have to get working on my own tool - perhaps based on interbase???;-)
Its interesting to look at the results of GM foods to see how bad things could get if we decided to start tampering with people. (and/or continue with plants). One interesting point in GM foods is how if you modify one plant, and that plant is grown outside the lab that you've now lost control - those genes can propogate to any plant that a bee decides to carry that pollen to! Oops! Lets make up an example (not too far from reality). Lets say a monster tomato plant, with genes that give it the ability to resist frost - given to it by an Artic Char Salmon is grown. Lots of tests are done, it works great! The tomatoes are sampled by a large test group - no problems. Looks like everything worked according to plan! So, its time to grow the tomatoes out in the real world, out of the lab now. One day, a bee decides to pollenate the tomatoes. But on a whim, the bee decides to fly waaay down the road to an apple orchard. That bee decides to sit on an apple tree, and now the fish allergy I have gets triggered when I eat an apple! How's that for a wonky effect - the scientists never saw that one coming! I mean, how could they? The tomato didn't seem to cause people with fish allergies any problems! Thats the problem with not understanding something fully - you can't percieve all of the secondary effects! UNTIL ITS TOO LATE! THOSE GENES ARE NOW 'out there' IN THE WILD! You can't get that bee back, that pollen is spread wild in the wind!
How about recessive genes? How can you possibly understand all of the interrelationships in something as complex as a human being if you can't figure out a tomato?? Cancers, growths, deformaties, defects that might not be present right away, but what about the next generation?
Until we can understand ALL of the effects, primary, secondary and all the interactions, why can't we keep it in the lab?
MONEY! I can grow bigger tomatoes if you just gimme some of those seeds from the lab!
So. What to do. Seems easy to me. Just don't go there.
But that flies right in the face of our societies need to explore, to experiment. Who can we trust to do it right? To experiment, but to keep it in the lab? And making sure that people arn't screwing with human genes - keeping it to plants and animals?
I would argue that we can't trust anyone. I think we should ban the whole mess.
Please show me how my logic is flawed. I'd love to know how we can reap the benefits of genetic modification without screwing up the world we have today.
I have no problem with technology. I love it, I embrace it... when I feel it performs it's function in a positive way (feel free to define positive yourself... I'll define it below to my terms).
Let's not innovate ONLY because we can. Let us take one step back for a moment and evaluate those technologies that may have the effect of changing our future forever - our ecosystem, planet, our 3rd world neighbours, etc.
How bout being a little forward thinking for once and getting a committee of the best and brightest (ahem.. us on Slashdot;-) ), to discuss some of the IMPLICATIONS of new technology before we blindly leap forward.
Just because we can, doesn't mean we should.
Genetically modified foods follows very quickly to genetically modified people.... and we all know from Sci-fi where that leads us. But does it have to end in unfair unjust class structures, the haves vs. the have-nots? Why even go there? What is the purpose of most of these technologies? You know it.... CASH baby! Big buisness has made its mind up... now its up to us, the people to say we can't live with the possible concequences!
What things are important to you? Really... be honest. Do you think that living forever is a fair goal? What about your children's children who will live on a planet unable to sustain them and their grandparents who are now 190?
So, I may be opening a can of worms here, but I think it's important to define goals for our society, as well as limits to certain technologies that MAY cause problems in the future.
This particualar issue of using cells from eels to drive circuits on robots is interesting ot a very low level. Its cool man. But where does it lead to? Why couldn't we have some time to talk about that first?
How about using aborted fetuses from pigs to do the same thing? How about 28 week human fetuses? How about criminals we execute? Where do we draw the line? Who draws the line?
My christian background helps me sort through a lot of these issues, and my world view and my scientific background helps me evalute a lot of these issues. My fear is that the people making the important decisions with regards to policies may not have the required skills to make the decisions OR EVEN WORSE... NOBODY EVEN THINGS ABOUT IT.
Too much information. Too big a topic! But that doesn't mean we can't use those big brains of ours and just ignore it and hope it goes away.
Basically the idea of using watermarks is flawed and the watermark can be easily removed or destroyed using simple tools available today. Note - watermarking can be also done to sound files... something else to remember!
Greeting from Newbridge Networks, where wireless LMDS networks (higher microwave frequencies used = MORE bandwidth) are already available TODAY! Read about it now! Come get your OC-3 or T1 pipe... ethernet available too...
Just so you know, I write this from the background of a hardware engineer in the Wireless group at Newbridge. If you have any questions, please post them. I'll be watching. Otherwise, try emailing me at "myname"@newbridge.com
I have SOOO many comments to make, I'm going to have to make them in point form otherwise I'll be here all day. So, here we go:
1. What Cisco is proposing using multipath effects to avoid the line-of-sight problems is asking a LOT. I really doubt this is possible. I was involved in a research project over a year ago that basically ruled out this from being possible.
problem A: If you use a non directional antenna (easiest to set up, no alignment issues) you are then presented with the amount of processing needed to weed out signal from reflections - it is enormous. Your antenna also has no gain - a big problem with lossy low power MMDS or LMDS systems. No signal = lots of noise = low bandwidth or high error rate.
problem B: The other problem is cost to install a system like this. Lets say you find a nice shiny building to bounce your microwave signal off of. It's a LOT tougher to align your dish antenna to a unknown point on a building (trial and error) then to point your dish to a fixed known point. This could NOT be done by joe blow on his roof - you would need a pro installer to do this with specialized test equipment = $$$$$! You also need to do LOTS of thinking about what reflection you are going to use - too much work to make it cheap. TIME = $$$$. The numbers they are quoting sound like marketing magic.
Enough marketing hoopla. Check out what we built... and you can have today!
Here's a few more links for you. Good techie stuff.
This technology doesn't work on the move. It isn't meant for vehicle platforms. Fixed sites only.
30 MILE range? I think not. NO WAY they could get regulated. Think of the interference problems on adjacent cells, especially since they are using the multipath effects.
Typical cell sizes for LMDS MMDS systems are around 4 Km. (2.5 miles)
ISP's love this stuff because it can get them into peoples homes - last mile. Don't need cable, dont need phone lines.
If you have any questions, please post em. Man, the signal to noise ratio in this topic has been pretty bad. I hope this helps clear a few things up.
I haven't seen too many solutions to this problem stated. I think I might have one.
We all know that teachers don't have the time and/or energy after teaching a class full of 30 kids (another problem... I'll save that rant for another day) to do the proper research into the topics they are to teach. They mainly stick by the textbook, and follow through their lesson plans. The REALLY lucky students out there get a teacher that takes it a step further, and tries to connect the textbook learning to more practical real life examples and attempts to use other sources of information to supplement the textbook (such as internet info, science shows taped from public TV, and public library visits).
So - how do we get the latest info into the textbooks? How about revisiting the idea of books all together? Wouldn't it be great if the book you owned updated it's self automatically? Well, with the internet and tools such as CVS the idea becomes a little more realistic.
I'm not proposing that CVS be used for anything other than keeping code in check - but what if a tool could be developed to make web publishing and updating textbooks easy and straightforward for publishers?
This might kill the textbook market as we know it - everybody would need palmpads or small notebooks to use as their text for the year - but the great thing is the following year you could just download the newest text from the net - and you have the latest and greatest info!
Publishers would have to charge a yearly renewal fee vs. every 10 years the school would buy new books. Sounds OK to me!
So, who out there is going to be brave enough to offer such a service to schools? In my opinion, if textbook publishers really cared about the quality of education, this would be a no-brainer.
This is SOOOO close to becoming feasable. I saw pictures in EETimes of some of the 'internet appliances' that are coming - and they seem ideal for students! Imagine a $99 dollar keyboard/LCD combo with just enough horsepower to drive a web browser that you could easily pack into your backpack.... very cool. If only they could get the resolution of the LCD up.
Taking something and making it more than it was. Yet another definition of hacking.
Here's a sweet example of that. Color TV.
TV seems pretty mundane and simple... till you start looking into it's origins.
Here's a cool link that goes into the history of color TV.
Imagine being tasked with the job of creating color TV - and then being told... oh ya... it has to work with the thousands of black and white TV's that are out there too. Doh!
Man - today we are spoiled. Super powerful processors that crunch the heck out of digital data. Imagine if we could redesign color TV today? Oh wait a sec - isn't that what HDTV is all about? Ah, forget it. Too much red tape bs.
Slashdot Mirror
Anybody know how those work?
Sounds cool...
The 1-800 number doesn't work in Canada or I suspect overseas. Try this number instead:
1-408-678-0032 if you don't mind the long distance charges. Its cool to hear pi to 9000 digits (doh!).
Have fun.
Wouldn't this cause more permanent damage to more delicate external organs like your eyes?
As an alternative, you could use this as mass birth control too... (heat up those testies!)
Ouch.
Nothin that a soldering iron and a pullup won't fix... till they integrate it into an ASIC.
When will the nonsense end? Just gimme good prices on stuff and I won't import it. Basterds!
From Secure Deletion of Data from magnetic and solid state memory.
In conventional terms, when a one is written to disk the media records a one, and when a zero is written the media records a zero. However the actual effect is closer to obtaining a 0.95 when a zero is overwritten with a one, and a 1.05 when a one is overwritten with a one. Normal disk circuitry is set up so that both these values are read as ones, but using specialised circuitry it is possible to work out what previous "layers" contained. The recovery of at least one or two layers of overwritten data isn't too hard to perform by reading the signal from the analog head electronics with a high-quality digital sampling oscilloscope, downloading the sampled waveform to a PC, and analysing it in software to recover the previously recorded signal. What the software does is generate an "ideal" read signal and subtract it from what was actually read, leaving as the difference the remnant of the previous signal. Since the analog circuitry in a commercial hard drive is nowhere near the quality of the circuitry in the oscilloscope used to sample the signal, the ability exists to recover a lot of extra information which isn't exploited by the hard drive electronics (although with newer channel coding techniques such as PRML (explained further on) which require extensive amounts of signal processing, the use of simple tools such as an oscilloscope to directly recover the data is no longer possible).
So, in conclusion - Sorry, can't be done without modifying the electronics in the drive. That might be a challenge to the drive manufacturers though... how to get your density doubled by purposefully use the overwrite and read both the previous and current data! Kind of the same idea as the two bits per cell technology used by flash memory manufacturers...
In Canada, if you send a letter to your MP, its free! I imagine in the states the same goes for your elected officials. So, if you really want things to change, bundle up all your junk mail and put a sticker:
To Such and Such, Member of Parliament
Parliament Hill, Ottawa
And away it goes!
There was an organized campaign a couple of years ago where Thousands of people did this and it ended up clogging up the mail room over at Canada's headquarters for a while. I don't remember if anything came out of this or not.
This is stupid. Talk about overkill.
;-)
How much processing power do you need to process a few sensors and drive a couple wheels? $200 bucks worth of palm? Uhh... how about $4 bucks worth of microcontroller like a nice 16C64 from PIC Microship microcontroller? Enough to make a hardware guy cry! Onboard RAM, ROM, EEPROM.... mmmmm..... timers and interrupt vectors.... 20mA drive current.... whoo-hooo! Just need a few H-Bridges and a couple infrared leds and detectors. You wanted to know what to do with those old 5 1/4" drives... its time to get out those irons and solder suckers!
I suppose this kit is nice for those software types that don't like to touch hardware, but what fun is that?
If you REAALY dont want to challenge yourself, and don't want to touch hardware, I would think a nice Lego mindstorms kit would be better suited and more flexable. Reconfigurable, and you can always buy more motors and sensors.
A freaking GUI for a robot? And thats a selling feature? Who needs a GUI anyways
How bout we have a new slashdot interview with Hemos to find out what is up with all the double postings lately ;-) (And other assorted questions... that tend to be repeated over and over...)
I'd like to see a interview for the Slashdot team ! Post your questions below....
Question 1. What's going on with the moderation scheme here at Slashdot? Anybody working on changes/improvements?
Tastes kind of like ham - add it to Kraft Dinner for a tasty treat!
Thanks Microsoft!
I found it refreshing to see some decent software testing going on. Why does it take two yahoos to find out that there are serious rendering differences in browsers? I guess this is another result of the 'browser wars'. Freaking guys, get together and come up with a standard!
If only people TESTED their software. Jeeze, you think somebody at Micro$oft would have at least found that silly rendering bug.
I guess that's the problem when you aren't working from a spec (just make it up as you go....) Is there a spec stating how colours are to be rendered mathematically? Ie round up or round down in these cases?
It seems logical to me that in order to solve some of these ambiguious choices there has to be a spec.
Back to our Library Discussion, wouldn't one of these babies work great for keeping track of those books!
I guess the only chance is that we get a couple of motivated geeks that see the problem, and start chomping off bits and pieces of it.
I've actually got some great news - because of this forum I've recieved a couple emails which have lead to the formation of a project on SourceForge - called Open Schoolhouse.
We're going to attempt to do what you call tough - the open source development of a School administration project.
We're going to start by developing a core database - then add on modules that can provide the different functions that various schools need! We're going to start with the report card generation stuff and go from there.
Check us out on SourceForge and if you feel you can contribute -anyone can help us- than please do! I look forward to talking to you all there!
I'm the guy that posed the question. Ok, here's the deal. I'm running various linux based services which basically run the school. Internet, file access, printing, backups - all the goodies are powered by open source software.
;-)
Our poor admin who runs the office though is being run ragged during the school year trying to keep various lists up to date, and producing dumb documents - like membership lists, student health records for when students go on class trips, transcripts - stuff like that. This is all being done semi-manually (spreadsheets and wordprocessing).
A database powered suite which provided admin type functions for a school - something that is flexable, extendable, and most importantly OPEN - so we can fix that reportcard when the format needs to change. That's the tool I'm looking for.
Maplewood offers a nice product - but it's closed source and its price would break our budget.
I've done the grunt work searching on freshmeat to no avail. I'll check out a few of the links posted above to see if anybody is working on anything now, otherwise I just might have to get working on my own tool - perhaps based on interbase???
Cheers,
Aaron
Its interesting to look at the results of GM foods to see how bad things could get if we decided to start tampering with people. (and/or continue with plants).
One interesting point in GM foods is how if you modify one plant, and that plant is grown outside the lab that you've now lost control - those genes can propogate to any plant that a bee decides to carry that pollen to! Oops!
Lets make up an example (not too far from reality). Lets say a monster tomato plant, with genes that give it the ability to resist frost - given to it by an Artic Char Salmon is grown. Lots of tests are done, it works great! The tomatoes are sampled by a large test group - no problems. Looks like everything worked according to plan! So, its time to grow the tomatoes out in the real world, out of the lab now. One day, a bee decides to pollenate the tomatoes. But on a whim, the bee decides to fly waaay down the road to an apple orchard.
That bee decides to sit on an apple tree, and now the fish allergy I have gets triggered when I eat an apple! How's that for a wonky effect - the scientists never saw that one coming! I mean, how could they? The tomato didn't seem to cause people with fish allergies any problems! Thats the problem with not understanding something fully - you can't percieve all of the secondary effects! UNTIL ITS TOO LATE! THOSE GENES ARE NOW 'out there' IN THE WILD! You can't get that bee back, that pollen is spread wild in the wind!
How about recessive genes? How can you possibly understand all of the interrelationships in something as complex as a human being if you can't figure out a tomato?? Cancers, growths, deformaties, defects that might not be present right away, but what about the next generation?
Until we can understand ALL of the effects, primary, secondary and all the interactions, why can't we keep it in the lab?
MONEY! I can grow bigger tomatoes if you just gimme some of those seeds from the lab!
So. What to do. Seems easy to me. Just don't go there.
But that flies right in the face of our societies need to explore, to experiment. Who can we trust to do it right? To experiment, but to keep it in the lab? And making sure that people arn't screwing with human genes - keeping it to plants and animals?
I would argue that we can't trust anyone. I think we should ban the whole mess.
Please show me how my logic is flawed. I'd love to know how we can reap the benefits of genetic modification without screwing up the world we have today.
I have no problem with technology. I love it, I embrace it... when I feel it performs it's function in a positive way (feel free to define positive yourself... I'll define it below to my terms).
;-) ), to discuss some of the IMPLICATIONS of new technology before we blindly leap forward.
Let's not innovate ONLY because we can. Let us take one step back for a moment and evaluate those technologies that may have the effect of changing our future forever - our ecosystem, planet, our 3rd world neighbours, etc.
How bout being a little forward thinking for once and getting a committee of the best and brightest (ahem.. us on Slashdot
Just because we can, doesn't mean we should.
Genetically modified foods follows very quickly to genetically modified people.... and we all know from Sci-fi where that leads us. But does it have to end in unfair unjust class structures, the haves vs. the have-nots? Why even go there? What is the purpose of most of these technologies? You know it.... CASH baby! Big buisness has made its mind up... now its up to us, the people to say we can't live with the possible concequences!
What things are important to you? Really... be honest. Do you think that living forever is a fair goal? What about your children's children who will live on a planet unable to sustain them and their grandparents who are now 190?
So, I may be opening a can of worms here, but I think it's important to define goals for our society, as well as limits to certain technologies that MAY cause problems in the future.
This particualar issue of using cells from eels to drive circuits on robots is interesting ot a very low level. Its cool man. But where does it lead to? Why couldn't we have some time to talk about that first?
How about using aborted fetuses from pigs to do the same thing? How about 28 week human fetuses? How about criminals we execute? Where do we draw the line? Who draws the line?
My christian background helps me sort through a lot of these issues, and my world view and my scientific background helps me evalute a lot of these issues.
My fear is that the people making the important decisions with regards to policies may not have the required skills to make the decisions OR EVEN WORSE... NOBODY EVEN THINGS ABOUT IT.
Too much information. Too big a topic! But that doesn't mean we can't use those big brains of ours and just ignore it and hope it goes away.
8 million users of AOL x $1000 damage per user = $8B.
I guess that means I can charge my buddies a grand to reinstall windows for them when a piece of crap software destroys their system?
Nah, I guess I'll just charge em my standard fee.
(They have to put up with me telling em about linux. )
Read here: Attacks on Copyright marking systems
A paper available from:
http://www.cl.cam.ac.uk/~fapp2/ papers/ih98-attacks/ Courtesy of Fabien A. P. Petitcolas, Computer Laboratory, University of Cambridge.
Basically the idea of using watermarks is flawed and the watermark can be easily removed or destroyed using simple tools available today. Note - watermarking can be also done to sound files... something else to remember!
Aaron Helleman
Greeting from Newbridge Networks, where wireless LMDS networks (higher microwave frequencies used = MORE bandwidth) are already available TODAY! Read about it now! Come get your OC-3 or T1 pipe... ethernet available too...
Just so you know, I write this from the background of a hardware engineer in the Wireless group at Newbridge. If you have any questions, please post them. I'll be watching. Otherwise, try emailing me at "myname"@newbridge.com
I have SOOO many comments to make, I'm going to have to make them in point form otherwise I'll be here all day. So, here we go:
1. What Cisco is proposing using multipath effects to avoid the line-of-sight problems is asking a LOT. I really doubt this is possible. I was involved in a research project over a year ago that basically ruled out this from being possible.
problem A: If you use a non directional antenna (easiest to set up, no alignment issues) you are then presented with the amount of processing needed to weed out signal from reflections - it is enormous. Your antenna also has no gain - a big problem with lossy low power MMDS or LMDS systems. No signal = lots of noise = low bandwidth or high error rate.
problem B: The other problem is cost to install a system like this. Lets say you find a nice shiny building to bounce your microwave signal off of. It's a LOT tougher to align your dish antenna to a unknown point on a building (trial and error) then to point your dish to a fixed known point. This could NOT be done by joe blow on his roof - you would need a pro installer to do this with specialized test equipment = $$$$$! You also need to do LOTS of thinking about what reflection you are going to use - too much work to make it cheap. TIME = $$$$.
The numbers they are quoting sound like marketing magic.
Enough marketing hoopla. Check out what we built... and you can have today!
Here's a few more links for you. Good techie stuff.
Check out: How to maximize the use of your available spectrum
and
Newbridge features, like QOS and awesome network management. Does CISCO offer this end to end networking? I think not.
More points:
This technology doesn't work on the move. It isn't meant for vehicle platforms. Fixed sites only.
30 MILE range? I think not. NO WAY they could get regulated. Think of the interference problems on adjacent cells, especially since they are using the multipath effects.
Typical cell sizes for LMDS MMDS systems are around 4 Km. (2.5 miles)
ISP's love this stuff because it can get them into peoples homes - last mile. Don't need cable, dont need phone lines.
If you have any questions, please post em. Man, the signal to noise ratio in this topic has been pretty bad. I hope this helps clear a few things up.
I haven't seen too many solutions to this problem stated. I think I might have one.
;-)
We all know that teachers don't have the time and/or energy after teaching a class full of 30 kids (another problem... I'll save that rant for another day) to do the proper research into the topics they are to teach. They mainly stick by the textbook, and follow through their lesson plans. The REALLY lucky students out there get a teacher that takes it a step further, and tries to connect the textbook learning to more practical real life examples and attempts to use other sources of information to supplement the textbook (such as internet info, science shows taped from public TV, and public library visits).
So - how do we get the latest info into the textbooks? How about revisiting the idea of books all together? Wouldn't it be great if the book you owned updated it's self automatically? Well, with the internet and tools such as CVS the idea becomes a little more realistic.
I'm not proposing that CVS be used for anything other than keeping code in check - but what if a tool could be developed to make web publishing and updating textbooks easy and straightforward for publishers?
This might kill the textbook market as we know it - everybody would need palmpads or small notebooks to use as their text for the year - but the great thing is the following year you could just download the newest text from the net - and you have the latest and greatest info!
Publishers would have to charge a yearly renewal fee vs. every 10 years the school would buy new books. Sounds OK to me!
So, who out there is going to be brave enough to offer such a service to schools? In my opinion, if textbook publishers really cared about the quality of education, this would be a no-brainer.
This is SOOOO close to becoming feasable. I saw pictures in EETimes of some of the 'internet appliances' that are coming - and they seem ideal for students! Imagine a $99 dollar keyboard/LCD combo with just enough horsepower to drive a web browser that you could easily pack into your backpack.... very cool. If only they could get the resolution of the LCD up.
Like I said.... close. Might save some trees too!
Patent Pending (tm)
Here's a funny one! Enjoy. In the spirit of the MIT hacks, here's a Waterloo Hack!
The Great Water Tower Caper
Taking something and making it more than it was. Yet another definition of hacking.
Here's a sweet example of that. Color TV.
TV seems pretty mundane and simple... till you start looking into it's origins.
Here's a cool link that goes into the history of color TV.
Imagine being tasked with the job of creating color TV - and then being told... oh ya... it has to work with the thousands of black and white TV's that are out there too. Doh!
Very cool hack.
Check it out.
History of Color TV
Man - today we are spoiled. Super powerful processors that crunch the heck out of digital data. Imagine if we could redesign color TV today? Oh wait a sec - isn't that what HDTV is all about? Ah, forget it. Too much red tape bs.
Grin
Ooops! Goto and Go. Now I see. Yep. That could be a problem.
Umm... who's the one with the trademarked Stoplight?
Who's pushing the change?