If you go to the National Academy Press web site, http://www.nap.edu/about.html, you will find that many of their books are available in PDF format, and that many of those can be downloaded for free. To find what you are interested in, use the search box in the upper left hand side of their about page. Since we taxpayers paid for most, if not all, of the work being presented, perhaps they all should be free.
An alternative is to look at the data - multiple processors should make dealing with data in the form of vectors and matrices much faster. However, you have to THINK in terms of vector and matrix data.
A language dating back to the 1960's and 1970's did just that - it was called APL (A Programming Language). Loops, while do-able (forgive the pun), were extremely wasteful of cpu time - by a factor of 80 to 100. The APL interpreter took care of that bookkeeping for you if you used vectors or matrices as whole entities rather than grinding through them element by element. The language was extremely rich in vector and matrix operators (and their combinations) which allowed a programmer to take advantage of that quirk/feature of the interpreter. The obvious step was to use parallel hardware. The word on the street was that interpreted APL ran faster on one of the few parallel cpus of the time than did compiled Fortran. Unfortunately APL did not transition well into GUI world, although at least one modern implementation is around.
APL was also the only truly interactive language I have run into, but that is another story.
The Landsat 2000 is from Landsat 7 and has a resolution of 15 meters/pixel. The Landsat 1990 data is from Landsats 4 and 5, and has a resolution of 30 meters/pixel.
The Landsat 2000 data set is the result of a planned campaign to obtain worldwide coverage; the Landsat 1990 data was collected from whatever was available and has gaps (particularly islands) which are covered in the Landsat 2000 data,
Some people like to stay on a project just long enough to include it on their resume, but don't stay around long enough to be productive. You need someone who has delivered an actual product - finished it, not toyed around with it.
2 - ask his/her co-workers on other projects (admittedly difficult to do.): Would you work for/with Mr/Ms X again?
Some people can deliver, but at a horrendous cost in morale, physical and mental health, etc. If he/she destroys or otherwise alienates your people so that they are unlikely to deliver again, you don't want him/her - he/she probably doesn't know what a "team" is.
The usual "did you meet tech requirements, cost, schedule, etc." are a given.
This brings up two points I was thinking about recently when I downloaded the new version of OO, namely
WHEN I (or someone else) UPGRADE, rather than a install on a "clean", OO-less system,
1) Do I need to keep the temp files - if so, I would stash them where I could find them or remember the (obvious) directory name,
and
2) Should I uninstall the old and then install the new, or just install over the old?
The installation instructions say NOTHING about upgrading from an earlier version. If OpenOffice has gone anywhere in the past, there are a lot of people with older versions on their machines who are probably pondering the above two questions.
I don't know the answers. CLEAR UPGRADE INSTRUCTIONS WOULD HELP.
Comeon. The Viet Nam war torpedoed the Apollo program before it was done, killing off the last missions to the moon. Why not the Iraq war torpedoing the Station? We've been there before. Guns...Butter...Guns...Butter... But not enough $$$ for both!
From the physics of the situation, at perigee (the lowest point in the orbit), kinetic enegry is at maximum, and potential energy is at its lowest. At apogee (the highest point in the orbit), the reverse is true - kinetic energy is at its lowest and potential energy is at its highest. The potential energy is directly related to the altitude - it is the energy due to gravity that is built-up as the object has farther to fall.
Atmospheric drag causes the spacecraft to shed kinetic energy, not potential energy. The atmosphere is most dense at the lowest altitude (perigee), assuming a highly eliptical orbit where at drag at apogee is much smaller than at perigee. The velocity is also highest at perigee, enhancing the drag which is proportional to velocity-squared.
Since energy is conserved (except for that lost to drag), leaving perigee there is less kinetic energy to convert to potential and the apogee drops lower - much more so than the drop in perigee. Hence, orbits circularize as they get lower due to atmospheric drag.
I was having major problems with my office H/W and had called the help(?) desk to no avail. I knew something was hosed internally. When the fix-it person showed, he/she fiddled around and generally did not believe me when I described the problem.
Finally, I left the room in disgust, only to return when I heard the loud comment: "You can't even play solitaire on this machine!!!!"
Needless to say, fixit person became a believer and replaced the hard drive + who knows what else.
One good reason to have solitaire on your machine is that EVERYONE KNOWS WHAT IT IS SUPPOSED TO DO. When it doesn't, even the skeptics have to admit something is wrong.
1) When the CPU speed has increased by at least a factor of 3 over the old box, and
2) when the price to buy such stuff descends to reasonable from stratospheric.
By then, the increased bus speed, higher/faster hard drives(?), and other up-to-date peripherals that tag along on the new motherboard (What? replace the whole box? Maybe, er... sometimes)are just icing on the cake.
p.s. Incremental upgrades, such as a USB 2 board, get added when on sale.
Re:NIMA vmap0 data
on
Open Maps?
·
· Score: 2, Informative
VMAP0 is crude compared to what is out there, and is not particularly reliable. For example, the Nile river is 1 mile or so mislocated at points. It may be the best worldwide vector map available for the price, BUT...
Try GlobalMapper (www.globalmapper.com) software, also known in a limited form as DLGV32PRO (check Google for a USGS site). Both are versions of the same thing - limited capabilities for free, everything for a relatively modest price (~$100-200 versus $1000's for heavy duty GIS S/W). GlobalMapper will also allow you to save raster and vector data in a different format. Very powerful for the price.
Slashdot Mirror
If you go to the National Academy Press web site, http://www.nap.edu/about.html, you will find that many of their books are available in PDF format, and that many of those can be downloaded for free. To find what you are interested in, use the search box in the upper left hand side of their about page. Since we taxpayers paid for most, if not all, of the work being presented, perhaps they all should be free.
An alternative is to look at the data - multiple processors should make dealing with data in the form of vectors and matrices much faster. However, you have to THINK in terms of vector and matrix data.
A language dating back to the 1960's and 1970's did just that - it was called APL (A Programming Language). Loops, while do-able (forgive the pun), were extremely wasteful of cpu time - by a factor of 80 to 100. The APL interpreter took care of that bookkeeping for you if you used vectors or matrices as whole entities rather than grinding through them element by element. The language was extremely rich in vector and matrix operators (and their combinations) which allowed a programmer to take advantage of that quirk/feature of the interpreter. The obvious step was to use parallel hardware. The word on the street was that interpreted APL ran faster on one of the few parallel cpus of the time than did compiled Fortran. Unfortunately APL did not transition well into GUI world, although at least one modern implementation is around.
APL was also the only truly interactive language I have run into, but that is another story.
The Landsat 2000 is from Landsat 7 and has a resolution of 15 meters/pixel. The Landsat 1990 data is from Landsats 4 and 5, and has a resolution of 30 meters/pixel.
The Landsat 2000 data set is the result of a planned campaign to obtain worldwide coverage; the Landsat 1990 data was collected from whatever was available and has gaps (particularly islands) which are covered in the Landsat 2000 data,
I would (somehow) ask two questions:
1 - ask the candidate: What have you DELIVERED?
Some people like to stay on a project just long enough to include it on their resume, but don't stay around long enough to be productive. You need someone who has delivered an actual product - finished it, not toyed around with it.
2 - ask his/her co-workers on other projects (admittedly difficult to do.): Would you work for/with Mr/Ms X again?
Some people can deliver, but at a horrendous cost in morale, physical and mental health, etc. If he/she destroys or otherwise alienates your people so that they are unlikely to deliver again, you don't want him/her - he/she probably doesn't know what a "team" is.
The usual "did you meet tech requirements, cost, schedule, etc." are a given.
This brings up two points I was thinking about recently when I downloaded the new version of OO, namely
WHEN I (or someone else) UPGRADE, rather than a install on a "clean", OO-less system,
1) Do I need to keep the temp files - if so, I would stash them where I could find them or remember the (obvious) directory name,
and
2) Should I uninstall the old and then install the new, or just install over the old?
The installation instructions say NOTHING about upgrading from an earlier version. If OpenOffice has gone anywhere in the past, there are a lot of people with older versions on their machines who are probably pondering the above two questions.
I don't know the answers. CLEAR UPGRADE INSTRUCTIONS WOULD HELP.
Thanks.
Comeon. The Viet Nam war torpedoed the Apollo program before it was done, killing off the last missions to the moon. Why not the Iraq war torpedoing the Station? We've been there before. Guns...Butter...Guns...Butter... But not enough $$$ for both!
Your simulations are incorrect. Decaying orbits circularize. See page 10 of the reference:
2 0Weather/Space%20Weather%20Effects/SatelliteOrbita lDecayCalculations.pdf>
http://www.ips.gov.au/Category/Educational/Space%
From the physics of the situation, at perigee (the lowest point in the orbit), kinetic enegry is at maximum, and potential energy is at its lowest. At apogee (the highest point in the orbit), the reverse is true - kinetic energy is at its lowest and potential energy is at its highest. The potential energy is directly related to the altitude - it is the energy due to gravity that is built-up as the object has farther to fall.
Atmospheric drag causes the spacecraft to shed kinetic energy, not potential energy. The atmosphere is most dense at the lowest altitude (perigee), assuming a highly eliptical orbit where at drag at apogee is much smaller than at perigee. The velocity is also highest at perigee, enhancing the drag which is proportional to velocity-squared.
Since energy is conserved (except for that lost to drag), leaving perigee there is less kinetic energy to convert to potential and the apogee drops lower - much more so than the drop in perigee. Hence, orbits circularize as they get lower due to atmospheric drag.
I was having major problems with my office H/W and had called the help(?) desk to no avail. I knew something was hosed internally. When the fix-it person showed, he/she fiddled around and generally did not believe me when I described the problem.
Finally, I left the room in disgust, only to return when I heard the loud comment: "You can't even play solitaire on this machine!!!!"
Needless to say, fixit person became a believer and replaced the hard drive + who knows what else.
One good reason to have solitaire on your machine is that EVERYONE KNOWS WHAT IT IS SUPPOSED TO DO. When it doesn't, even the skeptics have to admit something is wrong.
1) When the CPU speed has increased by at least a factor of 3 over the old box, and
2) when the price to buy such stuff descends to reasonable from stratospheric.
By then, the increased bus speed, higher/faster hard drives(?), and other up-to-date peripherals that tag along on the new motherboard (What? replace the whole box? Maybe, er... sometimes)are just icing on the cake.
p.s. Incremental upgrades, such as a USB 2 board, get added when on sale.
VMAP0 is crude compared to what is out there, and is not particularly reliable. For example, the Nile river is 1 mile or so mislocated at points. It may be the best worldwide vector map available for the price, BUT ...
Try GlobalMapper (www.globalmapper.com) software, also known in a limited form as DLGV32PRO (check Google for a USGS site). Both are versions of the same thing - limited capabilities for free, everything for a relatively modest price (~$100-200 versus $1000's for heavy duty GIS S/W). GlobalMapper will also allow you to save raster and vector data in a different format. Very powerful for the price.