The Big Secret of User Mode Linux
on
User Mode Linux
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· Score: 4, Interesting
I wanted to use User Mode Linux to simulate a complete production environment for a recent project. The big problem was that it didn't support the latest thread libraries. This was a big impediment to get Java running. Does the newest UML support running Java server apps?
Re:Mars Exploration Rovers and the future
on
Mars Rover Upgraded
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· Score: 1
What bugs me? It's that there isn't a good incremental and cheap approach being used. Success isn't being built upon. Design tweaks could reduce weight, instruments could be upgraded, riskier landing spots could be tried.
Take, for example, the parachutes used by Spirit and Opportunity. A team had to design, test, redesign, and repeat in order to make sure that they met their weight requirements and that they would function properly. If you watched the special on PBS about the rovers, you know all about this.
This process will have to be repeated for the much larger MSL.
Mars Exploration Rovers and the future
on
Mars Rover Upgraded
·
· Score: 4, Interesting
The current generation of rovers have shown themselves to be reliable and very flexible. They've brought back a view of Mars that far surpasses anything we've seen before. It's really disappointing, therefore, that NASA is throwing away all of the knowledge used to make these missions a success. Delivery of a robot to Mars requires a successful launch, accurate navigation, and, of course, a good landing. To say nothing of the design of the rovers themselves. All of this must be carefully worked out in advance.
But NASA has decided instead to throw away all of that and spend money to develop a new, bigger probe, the Mars Science Labratory. It's a shame that the limited science money NASA gets isn't being spent in the most efficient way possible on stuff that we know to will give excellent scientific data, but instead is used for these kinds of big budget employment makers.
A couple of the top contenders, who have been working on this type of vehicle even before the prize was announced are: Masten Space Systems and John Carmack's Armadillo Aerospace.
Unfortunately, the pro version offers one critical feature that the free version doesn't:
Access to the following 3D export formats: DWG, DXF, 3DS, OBJ, XSI, VRML and FBX.
If you're going to have something manufactured from a SketchUp design, you'll need to be able to export in a format that can be read by something other than SketchUp. I'll save you the trouble of looking it up: the Pro version is $495.00 for both Windows and Mac. You can get a free trial of the pro version, though.
The legs appear to be made with 5 parallel actuators, much like the Stewart-Gough platform used in motion simulators, machine tools, and the like. This is an extremely stable design that is very fault tolerant and able to remain stable, even if any one of the actuators becomes disabled.
It doesn't seem that useful, at least if 1) your phone and laptop both support Bluetooth and 2) you're carrying your cellphone anyway. You can just run the network connection over Bluetooth. So I'm told by my Cingular sales rep, anyway.
Much of the interactivity and cross platform capability we're being promised with AJAX sounds suspiciously like the buzz surrounding Java applets 10 years or so ago. However, AJAX is currently in a pretty primitive state. You still have to worry about browser compatibility issues. Tools and libraries are pretty simplistic. You also face the fun issue of dealing with yet another programming language, in addition to whatever HTML, SQL, and XML you're using, plus your server-side language of choice.
Given all of this, is AJAX really worth it for web applications?
The movie's most redeeming feature is that it gets across the idea that computers should be used for the free distribution of information. The evil MCP is the one that blocks off all access to the I/O towers, forcing our heroes to embark on their quest.
Here in Georgia, USA, at least, you can make one phone call and have all underground gas, cable, phone, sewer, and electric lines located for you. For free. People come from the various services and stick little flags in the ground over the lines.
I had to do this when I dug up part of my front yard to put in a flower bed.
For doing software simulations of walking creatures or robots, I've used the Yobotics Simulation Construction Set. It's reasonably easy to get started, given the complexity of physics simulations. Also, they have a free trial download, so it's great if, like me, you just want to play around.
As I was struggling through an Oracle install a while back that Oracle doesn't have a great incentive to keep their products easy to use. Many common tasks, such as adding a column to a table or even just allowing clients to connect, are needlessly complex. I figure that this is actually part of their business model. Customers realize that they're in over their heads with the Oracle database, so they pay for premium support, trained Oracle consultants, and the like. Think of all the consultants who would starve if Oracle was easy to use.
Contrast this with MySQL. Installation is a breeze, and it's pretty flexible after it's installed: you can add or resize columns on the fly. Plus no TNSNAMES.ORA to worry about. I figure this is because MySQL is open source and the developers want to get you productive right away so that you continue to use their system, and eventually pay them for consulting and support, even when your application has outgrown the software.
I'm sure that this comment won't be read by many since I'm posting this late, but I'd like all the fighting robot fans to know that many of the Battlebots competitors are still out there. Check out the Robot Fighting League: http://botleague.org/
You know, I like articles from Forbes, but those slideshow things they like to use have got to go. Did some editor actually think that they make the articles better?
Maybe it has something to do with the fact that it's a lot of trouble to upgrade to SP2?
I recently had to re-install XP on a laptop that came with SP1. It took about 4 cycles of going to the Windows Update site, getting it to install the patches, and rebooting. It was over an hour before I was done. I have a hard time imagining regular users wanting to do this. MS needs to change their update process so that it can be done all at once.
It's only useless if you've never had to create any physical objects. I've used it for such varied tasks as building robot chassis and making a retaining wall for my front yard.
Polyethylene is one of the most commonly used plastics in the world, and is found in plastic grocery bags, cutting boards, milk jugs, disposable cups, and about a million other things. It's very stretchy, and thus is unlikely to break. It's tough, so that when it gets a hole or crack, the structure keeps its integrity. That's why I use it for armor on my fighting robots.
According to MatWeb, Ultra High Molecular Weight Polyethylene (UHMW-PE) has an ultimate tensile strength of
about 40 MPa, while 7075 alloy aluminum has an ultimate tensile strength of
524 MPa
. The article claims that this new PE-derived material has a tensile strength 3x that of aluminum. I find a 40x improvement in tensile strength a bit tough to believe.
Slashdot Mirror
You should check us out. We currently offer waterjet cutting, which is cheaper than many of the processes listed in this thread.
I just tried registering as a seller on Google Checkout. I get the following error when entering my total sales and EIN:
6 27138
Oops!
An error occurred while processing your request.
Apparently, I'm not the only one having problems with this new service:
http://slashdot.org/comments.pl?sid=189880&cid=15
I wanted to use User Mode Linux to simulate a complete production environment for a recent project. The big problem was that it didn't support the latest thread libraries. This was a big impediment to get Java running. Does the newest UML support running Java server apps?
What bugs me? It's that there isn't a good incremental and cheap approach being used. Success isn't being built upon. Design tweaks could reduce weight, instruments could be upgraded, riskier landing spots could be tried.
Take, for example, the parachutes used by Spirit and Opportunity. A team had to design, test, redesign, and repeat in order to make sure that they met their weight requirements and that they would function properly. If you watched the special on PBS about the rovers, you know all about this.
This process will have to be repeated for the much larger MSL.
But NASA has decided instead to throw away all of that and spend money to develop a new, bigger probe, the Mars Science Labratory. It's a shame that the limited science money NASA gets isn't being spent in the most efficient way possible on stuff that we know to will give excellent scientific data, but instead is used for these kinds of big budget employment makers.
er, that should be http://www.armadilloaerospace.com/
A couple of the top contenders, who have been working on this type of vehicle even before the prize was announced are: Masten Space Systems and John Carmack's Armadillo Aerospace.
would avoid giving interviews to the press.
-
Access to the following 3D export formats: DWG, DXF, 3DS, OBJ, XSI, VRML and FBX.
If you're going to have something manufactured from a SketchUp design, you'll need to be able to export in a format that can be read by something other than SketchUp. I'll save you the trouble of looking it up: the Pro version is $495.00 for both Windows and Mac. You can get a free trial of the pro version, though.The legs appear to be made with 5 parallel actuators, much like the Stewart-Gough platform used in motion simulators, machine tools, and the like. This is an extremely stable design that is very fault tolerant and able to remain stable, even if any one of the actuators becomes disabled.
It doesn't seem that useful, at least if 1) your phone and laptop both support Bluetooth and 2) you're carrying your cellphone anyway. You can just run the network connection over Bluetooth. So I'm told by my Cingular sales rep, anyway.
Much of the interactivity and cross platform capability we're being promised with AJAX sounds suspiciously like the buzz surrounding Java applets 10 years or so ago. However, AJAX is currently in a pretty primitive state. You still have to worry about browser compatibility issues. Tools and libraries are pretty simplistic. You also face the fun issue of dealing with yet another programming language, in addition to whatever HTML, SQL, and XML you're using, plus your server-side language of choice.
Given all of this, is AJAX really worth it for web applications?
The movie's most redeeming feature is that it gets across the idea that computers should be used for the free distribution of information. The evil MCP is the one that blocks off all access to the I/O towers, forcing our heroes to embark on their quest.
I'll have you know that landscaping is very manly.
Here in Georgia, USA, at least, you can make one phone call and have all underground gas, cable, phone, sewer, and electric lines located for you. For free. People come from the various services and stick little flags in the ground over the lines.
I had to do this when I dug up part of my front yard to put in a flower bed.
For doing software simulations of walking creatures or robots, I've used the Yobotics Simulation Construction Set. It's reasonably easy to get started, given the complexity of physics simulations. Also, they have a free trial download, so it's great if, like me, you just want to play around.
Yes, and there is an economy built around getting you to the point where you can understand what's going on.
As I was struggling through an Oracle install a while back that Oracle doesn't have a great incentive to keep their products easy to use. Many common tasks, such as adding a column to a table or even just allowing clients to connect, are needlessly complex. I figure that this is actually part of their business model. Customers realize that they're in over their heads with the Oracle database, so they pay for premium support, trained Oracle consultants, and the like. Think of all the consultants who would starve if Oracle was easy to use.
Contrast this with MySQL. Installation is a breeze, and it's pretty flexible after it's installed: you can add or resize columns on the fly. Plus no TNSNAMES.ORA to worry about. I figure this is because MySQL is open source and the developers want to get you productive right away so that you continue to use their system, and eventually pay them for consulting and support, even when your application has outgrown the software.
I'm sure that this comment won't be read by many since I'm posting this late, but I'd like all the fighting robot fans to know that many of the Battlebots competitors are still out there. Check out the Robot Fighting League:
http://botleague.org/
You know, I like articles from Forbes, but those slideshow things they like to use have got to go. Did some editor actually think that they make the articles better?
I recently had to re-install XP on a laptop that came with SP1. It took about 4 cycles of going to the Windows Update site, getting it to install the patches, and rebooting. It was over an hour before I was done. I have a hard time imagining regular users wanting to do this. MS needs to change their update process so that it can be done all at once.
It's only useless if you've never had to create any physical objects. I've used it for such varied tasks as building robot chassis and making a retaining wall for my front yard.
Behold: the Telecrapper.
According to MatWeb, Ultra High Molecular Weight Polyethylene (UHMW-PE) has an ultimate tensile strength of about 40 MPa, while 7075 alloy aluminum has an ultimate tensile strength of 524 MPa . The article claims that this new PE-derived material has a tensile strength 3x that of aluminum. I find a 40x improvement in tensile strength a bit tough to believe.
Space Shuttle and Saturn V's
Space Shuttle Complex