The term "safety critical" literally refers to the safety of human lives and property. But it is commonly used in a figurative sense to mean the very special case of software that is subject to certification such as DO-178B etc. The state of the art in certifiably correct software is that it is possible only for extremely constrained, static, small scale systems. Military combat management systems are obviously safety critical in the literal sense, and many if not most of them pose greater risks to human lives and property than do safety critical systems in the figurative sense, such as digital avionics flight control systems. But military combat platform, combat management, and battle management software systems are intrinsically dynamic and large scale -- e.g., O(10^6) or more lines of code. I don't know of any such system that could be constructed using synchronous techniques -- in the sense I assume you intend, meaning Kopetz's time-triggered or the French school (Esterel et al.) of thinking. Those make presumptions that cannot be satisfied in the real world of highly dynamic and uncertain systems.
I was observing that the description at globalsecurity.org stated that the use of a laser here was for metrology of the optics, not for shooting down enemy satellites etc. as some posters have suggested or alleged.
"The Large Millimeter Wave Telescope (LMT) program is the U.S.-complement to a coordinated U.S.-Mexico project. The DARPA program is providing technology assessments for design, systems integration and technology-leading metrology for a 50-meter aperture, fully steerable millimeter wave radio telescope. The fully developed telescope features a sophisticated laser metrology system to maintain precise alignment of the optics, and real-time closed loop adaptive control to maintain a near-perfect parabolic surface at all pointing angles and under most environmental conditions."
Metrology: the science that deals with measurement.
HF RADARs [Re:This only works at night?]
on
HAARP Amping It Up
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· Score: 3, Informative
As someone whose professional application domain includes RADAR, I verify that HF RADAR is a currently deployed and advancing technology. Over the horizon RADAR's, which are on the HF band, such as the Upgraded Early Warning RADAR, are alive and well. Do a search for "UEWR" at globalsecurity.org.
A U.S. Government employee (among others) signs a legally binding document that attempts to help make it clear to the employee what his legal responsibilities are with respect to protection of information that has not been formally cleared for public release. In addition, employees are expected to have and exercise good judgment and to be trusted by their employer on that basis. Of course there is a relatively small number of special cases, some of which make the national news media and others of which are never known outside a small circle much less publicly.
I have many hundreds of professional society papers and technical reports, many hundreds of PowerPoint presentations (some with embedded videos). Yes, I carry about 64 DVD's of documents in my laptop case, but it is really useful to be able to have immediate access on my HDD to a lot of my documents, and still have room to download hundreds of megs of docs on no notice.
I put this in my Dell D800 laptop and XP Pro couldn't format it. I took it out, put it in an external box with an AC power supply, plugged it into the USB port, and it formatted fine. Then I put it back in the D800 and it works fine there too. This puzzles me, perhaps someone can help me understand it.
I DO need CD's and DVD's for data
on
Palmtop Nirvana?
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· Score: 2, Insightful
I carry around a dozen DVD-R's full of documents. I can read them anywhere. Even if there were a network connection available where I go in companies they don't let you connect your laptop to their network. And when I can connect to a network, it would take forever to download a lot od documents.
PC Card slot for Aircard 555 1XRTT modem
on
Palmtop Nirvana?
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· Score: 1
Until these CDMA modems get down to CF and maybe someday to SD format, a PC Card (ne'e PCMCIA) slot is mandatory to give me 1XRTT speed Internet access. Today, that means either the former HP iPaq's with the PC Card jacket and a plug-on thumb-type keyboard, or -- better yet -- a Handheld PC: the dearly departed HP Jornada 72X or the NEC Mobile Pro 900. I have two of both but prefer the NEC because the Jornada requires a docking station for charging and PC interface.
p.s. I use WiFi and AirCard555 CDPD 1XRTT modem PC cards in mine for email (even to Exchange) and web browsing. I also have a Hitachi 4GB CF card in it for storage. Even with these, it runs for many hours.
If all you want to do is write, a laptop is an overkill power-wise. The MobilePro 900 has a 90% size keyboard and a half-VGA screen and runs a long time on a charge; the Journada 72X is similar but smaller. You can even use the stalwart Radio Shack 100 (www.club100.com) and its descendents, which use AA batteries.
Slashdot Mirror
The 770 and Pepper Pad are cool, but lack the killer feature: an EVDO modem or at least a PC card slot for one.
The term "safety critical" literally refers to the safety of human lives and property. But it is commonly used in a figurative sense to mean the very special case of software that is subject to certification such as DO-178B etc. The state of the art in certifiably correct software is that it is possible only for extremely constrained, static, small scale systems. Military combat management systems are obviously safety critical in the literal sense, and many if not most of them pose greater risks to human lives and property than do safety critical systems in the figurative sense, such as digital avionics flight control systems. But military combat platform, combat management, and battle management software systems are intrinsically dynamic and large scale -- e.g., O(10^6) or more lines of code. I don't know of any such system that could be constructed using synchronous techniques -- in the sense I assume you intend, meaning Kopetz's time-triggered or the French school (Esterel et al.) of thinking. Those make presumptions that cannot be satisfied in the real world of highly dynamic and uncertain systems.
I was observing that the description at globalsecurity.org stated that the use of a laser here was for metrology of the optics, not for shooting down enemy satellites etc. as some posters have suggested or alleged.
"The Large Millimeter Wave Telescope (LMT) program is the U.S.-complement to a coordinated U.S.-Mexico project. The DARPA program is providing technology assessments for design, systems integration and technology-leading metrology for a 50-meter aperture, fully steerable millimeter wave radio telescope. The fully developed telescope features a sophisticated laser metrology system to maintain precise alignment of the optics, and real-time closed loop adaptive control to maintain a near-perfect parabolic surface at all pointing angles and under most environmental conditions."
Metrology: the science that deals with measurement.
As someone whose professional application domain includes RADAR, I verify that HF RADAR is a currently deployed and advancing technology. Over the horizon RADAR's, which are on the HF band, such as the Upgraded Early Warning RADAR, are alive and well. Do a search for "UEWR" at globalsecurity.org.
A U.S. Government employee (among others) signs a legally binding document that attempts to help make it clear to the employee what his legal responsibilities are with respect to protection of information that has not been formally cleared for public release. In addition, employees are expected to have and exercise good judgment and to be trusted by their employer on that basis. Of course there is a relatively small number of special cases, some of which make the national news media and others of which are never known outside a small circle much less publicly.
That "review" was vacuuous. In the portable HDD class, I have three favorites: 1) the I/O Magic Gigabank Elite 40 40GB 1.8" HDD, which is completely single-USB port powered, cool looking, has a built-in short USB cable, and is smaller than portable 2.5" HDD's -- see http://www.iomagic.com/gigabank/IUSB40HD18.asp. 2) The Memorex 4GB Mega Travel Drive, which looks like that Hitachi 4GB CF HDD packaged in a little box with a built-in USB connector, and includes a cool little leather case -- see http://www.memorex.com/html/products_detail.php?se ction=3&CID=12&SID=16&PID=1000&FID=151&opento=12#. 3) The Freecom FHD-XS 60GB 1.8" HDD, only about 3" square, bus powered with built-in USB connector -- see http://www.freecom.com/US-Product.asp?ID=999310&pa ge=USHARDDRIVES&SCatID=999314. I own all three of these -- each has a use, and I love them.
Interesting, thank you. But since it is only 120GB, I can't reach 128GB so I should be OK.
I have many hundreds of professional society papers and technical reports, many hundreds of PowerPoint presentations (some with embedded videos). Yes, I carry about 64 DVD's of documents in my laptop case, but it is really useful to be able to have immediate access on my HDD to a lot of my documents, and still have room to download hundreds of megs of docs on no notice.
I put this in my Dell D800 laptop and XP Pro couldn't format it. I took it out, put it in an external box with an AC power supply, plugged it into the USB port, and it formatted fine. Then I put it back in the D800 and it works fine there too. This puzzles me, perhaps someone can help me understand it.
I carry around a dozen DVD-R's full of documents. I can read them anywhere. Even if there were a network connection available where I go in companies they don't let you connect your laptop to their network. And when I can connect to a network, it would take forever to download a lot od documents.
Until these CDMA modems get down to CF and maybe someday to SD format, a PC Card (ne'e PCMCIA) slot is mandatory to give me 1XRTT speed Internet access. Today, that means either the former HP iPaq's with the PC Card jacket and a plug-on thumb-type keyboard, or -- better yet -- a Handheld PC: the dearly departed HP Jornada 72X or the NEC Mobile Pro 900. I have two of both but prefer the NEC because the Jornada requires a docking station for charging and PC interface.
p.s. I use WiFi and AirCard555 CDPD 1XRTT modem PC cards in mine for email (even to Exchange) and web browsing. I also have a Hitachi 4GB CF card in it for storage. Even with these, it runs for many hours.
If all you want to do is write, a laptop is an overkill power-wise. The MobilePro 900 has a 90% size keyboard and a half-VGA screen and runs a long time on a charge; the Journada 72X is similar but smaller. You can even use the stalwart Radio Shack 100 (www.club100.com) and its descendents, which use AA batteries.