Well California "saved" money by buying bridge components (cables, towers, deck, etc) for the new San Francisco-Oakland Bay Bridge from foreign sources. That "frees" up money for other pet projects.
I doubt it's a problem. An Asteroid is not a Meteorite.
"A meteorite is a natural object originating in outer space that survives impact with the Earth's surface" - Wikipedia - Meteorite
So unless someone plans on mining an asteroid by slamming it into the planet, they probably don't have to deal with laws pertaining to meteorites. There is also the fact that US law does not extend to the Asteroid Belt.
Unless you plan to use the mined material on the Moon, you are eventually going to take it down on Earth, and maybe inside the US. Then the federal laws would apply and your rocks/metals would fit the definition of "surviving impact with the Earth's surface", wouldn't they?
A controlled landing is not an impact. Back to the dictionary for a second round:
"impact - the striking of one thing against another; forceful contact; collision"
Probably because some chip inside the iPod says its maximum operating altitude is 10,0000 ft. If a supplier says that is all the chip is rated for that is what Apple has to put on the box.
Interestingly chip suppliers sometimes have chips that are mil-spec (military grade) that are rated for higher altitudes. What is the difference, aside from price, sometimes it is merely a matter of testing. Chips rated as mil-spec may actually get tested at low pressure (simulating high altitude). Regular chips get no such testing and may actually be capable of working at higher altitudes.
Fully agreed. I'd like to see a statistician pop in here and talk about confidence levels too. Just because the average is 1 in 300M for a fatal crash, that doesn't mean that by driving 300M miles with no crash means that we're safer. That's like flipping a coin where tails = fatality. If you flip it twice and both come up heads, that just means you got lucky.
I am not a statistician but I've had enough stats classes to know that there should be a "all other things equal" somewhere in your statement.:-)
OK, maybe I'm paranoid, but I usually get the download file and the MD5 from separate sources. Ideally the MD5 is from the home site of the project rather than one of its mirrors.
I hope by "representative" they mean diverse traffic and road conditions that represents the various things that a driver will experience over their driving career.
While on this thought I don't expect self-driving vehicles to be universally permitted. There will probably be limitations on the conditions under which an automated driving mode may be used.
As a side note, I believe the FAA adopted a statistical approach to safety regarding civilian space flight. That space flight should be no more hazardous than early commercial airline travel, I think the 1920s was used a baseline. Well at least that was the tentative plan at some point according to a presentation from some folks up at Mohave Spaceport.
... does what its programming tells it to do, avoid hitting other vehicles...
Its a bit of an assumption to believe that the driving software has that single goal. Staying on the road seems to be something the software is already considering. I wouldn't be surprised if existing software already has "prepare for crash" code that tightens seat belts, unlocks doors,... maybe even sends an "oh shit" text message to the road side assistance service.
... for once, we all should be thankful for our lawmakers' inability to act...
Only once? While gov't does occasionally get things right, getting it wrong is hardly a rare instance.
Think about how often gov't gets it wrong with respect to tech issues. The truth is they get it wrong just as often in other domains as well. We merely don't understand those other domains so we don't see the problems, we read some news article and all we see is legislation with good intentions. I'm sure some non-techie is reading an article about gov't going to increase cybersecurity and is thinking "sounds like a good idea".
IMHO we in the U.S. are judging our politicians too often by their good intentions rather than their actual performance, and politicians have adapted to this environment accordingly. All they really care about is that they hold the "correct" stand on an issue, not actually accomplishing anything. Until we start voting out people because they supported well intended but poorly thought out legislation little will change.
What is the point of all this? Have you jumped to the erroneous conclusion that I don't think any of these three implementation details have their time and place?
My original point has nothing to do with how one implement's the needed assembly code. My point is that there are situations where the programmer has knowledge that can not be communicated to the compiler, knowledge that allows the assembly language programmer to generated better code than the compiler could.
Using stand-alone assembly means that the compiler has to create an entire call frame and ensure that all caller-safe registers are preserved, even if your asm code doesn't touch any of them.
No. The responsibility to preserve registers is the assembly language programmer's and is done in the stand alone assembly. The compiler does not know a function is implemented in assembly. All the compiler ever sees is a prototype of a function in a header, it has no idea if that function is implemented in a separate C file or a separate assembly file.
Using inline assembly is a bit better, but the compiler still often has to treat your asm as a full barrier and so can't reorder operations around it to make most efficient use of the pipeline.
No inline is not necessarily better. The preamble/postamble code may be too aggressive.
The compiler leaving instruction ordering alone is a *good* thing. That is one of the point's of assembly, the human programmer can sometimes do a better job at pipeline management.
Using intrinsics means that the register allocator and instruction scheduler are entirely free to make any changes that they need to, as long as the end result is the same.
And as I said before intrinsics are sometimes the best way to implement a line or two of assembly.
The proper syntax for that is (using x64 types) something like:
int a,b,z;
z = (int)(((long long)a * b) >> 32);
I'm assuming int is 32bit and long long is 64. Even though a is promoted to a larger type and also b, good compilers know that the upper half of those promoted variables are not relevant. They will then use the 32bit multiply, shift the 64bit result and store the part you need.
Admittedly its been a while since I did fixed point but back in the day when I checked popular 32-bit x86 compilers (MS and gcc) they did not generate the couple of instructions that an assembly language programmer would. My example may be dated.
It's very different. Clearly you haven't done significant amount of work with the two to be able to tell.
That is a very bad guess on your part. Intel x86 and PowerPC assembly were a specialty of mine for many years. Whether I was writing a larger function in a standalone.asm file, doing a smaller function or a moderate number of lines as inline assembly in C/C++ code, or only need a line or two of assembly that could be implemented via a compiler intrinsic hardly matters. I was thinking and programming as an assembly programmer not a C/C++ programmer. Standalone.asm, inline assembly or intrinsic are just implementation details; each having their appropriate time and place.
You don't need to use assembly for this, you can just use built-ins or intrinsics. Assembly is only useful if you want to control register usage.
Which are really just alternative ways to write a line or two of assembly code. They are just conveniences, you are still leaving the C/C++ language and dropping into architecture specific assembly.
...companies thinking in the long run prefer an intelligent or well-trained workforce to automation and minimum wage.
In general your point does have some merit but it really does depend on the specific task at hand. My grandfather was a master welder. However for *some* of the tasks that he used to perform a robotic welding system would be a better idea.
The question I have is how it's less expensive (in the long run) to lay a chip out by hand once instead of improving your VLSI layout software forever. NP classification notwithstanding.
Coding in assembly still remains a superior method of squeezing extra performance out of software. It's just that few people do it because compilers are "good enough" at guessing which optimizations to apply, and where, and usually development costs are the primary concern for software development. But when you're shipping hundreds of millions of units of hardware, and you're trying to pack as much processing power in a small and efficient form factor, you don't go with VLSI for the same reason you don't go with a compiler for realtime code: You need that extra few percent.
I like to view things as a little more complicated than just applying optimizations. IMHO assembly gets some of its biggest wins when the human programmer has information that can't quite be expressed in the programming language. Specifically I recall such things in the bad old days when games and graphics code would use fixed point math. The programmer knew the goal was to multiply two 32-bit values, get a 64-bit result and right shift that result back down to 32 bits. The Intel assembly programmer knew this could be done in a single instruction. However there wasn't any real way to convey the bit twiddling details of this fixed point multiply to a C compiler so that it could do a comparable operation. C code could do the calculation but it needed to multiply two 64-bit operands to get the 64-bit result.
There's one purpose for alcohol, and Vodka tends to accomplish that faster and with less vomiting and hangovers. So I'll raise my glass, which is cheaper here than anywhere else, and toast Vodka's awesomeness.
There are at least three practical purposes. Add disinfectant to the list, also add fuel / fire starter when the proof gets above (80?). Obviously these are not the intended purposes but Vodka has been used in these ways when the circumstances warranted.
The following explanation has been attempted in many armies over many years:
"Sir, that is not a still. That is an apparatus creating field expedient disinfectant for the doctors/medics/corpsmen, sir."
Which part in the iPhone 5 or iPhone 4(S) develop, for starters?
For one, the CPU. From wiki:
"The A6 is said to use a 1.2 GHz[3][4][5] custom Apple-designed ARMv7 based dual core CPU,[1] rather than standard cores like in previous designs, and an integrated triple core SGX 543MP3[6] graphics processing unit (GPU) with the same performance as the previous Apple A5X processor found in the third-generation iPad. The SGX 543MP3 is running at 266MHz."
Software development has costs too. Even FOSS software has paid developers at times, the success of some FOSS projects has been tied to this fact.
Is that a lot of CSci depts (particularly at community colleges and other places that have associate's degrees) across the country have received grant money from Microsoft itself. That will, of course, make it much more difficult for you to convince them to stop "teaching" Microsoft Office.
That plus the fact that many students *want* to be using the tools that are used in the workplace. As long as MS Office dominates the workplace many students will want to use it in college.
The same is true for operating systems to a degree. During the 90s at a state university it was a common request that more classes allow assignments be done is a MS Windows environment. Many students wanted to do their projects using the same operating system and development tools as was commonly used in industry.
For a modern incarnation of this tendency look at the popularity of iOS programing classes at places like Stanford.
If there is no interaction with a professor and fellow students then these are not very good university courses.
There is actually little that is new here, one way presentation of information are centuries old, that is what books are.
Yes there are people that can learn from such presentations. However those individuals are exceptionally rare. That is why Universities evolved, because books alone were not enough.
You don't learn anything useful by having someone tell you the 'right answer' to a made-up problem.
And that *is not* what happens in real university level classes.
The point of the problems is to learn to think about the issues and build the skills needed to find answers.
And that *is* what happens in real university level classes. Sadly however that is not what happens in all university/college classes. Yet it happens far more often than when merely reading or engaging in some other one way presentation. By "real" I was not referring to a class that merely takes place on a university/college campus, some classes are good, some are not, it has a lot to do with the professor and/or TA.
Study groups are places where students can help each other build these skills. Even in face-to-face tutorials, a good TA doesn't just tell students the answers, but helps them find their own ways to the answers.
I'd fathom(sorry) that the strength of a hatch is proportional to the inverse cube of its linear size; two powers for the force (P = F/A hence F = PA) and another for the leverage caused by the distance from the hinge. A submersible drone carrier could well be quite feasible; bear in mind that there already has to be a hatch at least a meter in diameter for the crew to enter.
I believe the dry deck shelters mounted on submarines to launch and recover swimmers and vehicles are close to 3 meters in diameter.
Does *nobody* RTFA anymore? It is an Android vulnerability. They used NFC as one of several ways to exploit it. They could have done the whole thing without using NFC at all.
You are actually supporting my suggestion that NFC is the real subject. An Android vulnerability is found, not exactly big news. That NFC can be the exploit vector, that is new and different.
Slashdot Mirror
Nice to see California is flush with cash.
Well California "saved" money by buying bridge components (cables, towers, deck, etc) for the new San Francisco-Oakland Bay Bridge from foreign sources. That "frees" up money for other pet projects.
Unless the materials mined in space magically disappear, will they not have survived their impact with the Earth's surface when their spaceship lands?
By definition controlled landings are not impacts.
Actually, US law shouldn't extend beyond the USA borders :D
US laws apply to US flagged vessels. It will probably work for spacecraft much like it works for boats.
Unless you plan to use the mined material on the Moon, you are eventually going to take it down on Earth, and maybe inside the US. Then the federal laws would apply and your rocks/metals would fit the definition of "surviving impact with the Earth's surface", wouldn't they?
A controlled landing is not an impact. Back to the dictionary for a second round:
"impact - the striking of one thing against another; forceful contact; collision"
Maximum operating altitude: 10,000 feet (3000 m)
Really? What would cause this.
Probably because some chip inside the iPod says its maximum operating altitude is 10,0000 ft. If a supplier says that is all the chip is rated for that is what Apple has to put on the box.
Interestingly chip suppliers sometimes have chips that are mil-spec (military grade) that are rated for higher altitudes. What is the difference, aside from price, sometimes it is merely a matter of testing. Chips rated as mil-spec may actually get tested at low pressure (simulating high altitude). Regular chips get no such testing and may actually be capable of working at higher altitudes.
Fully agreed. I'd like to see a statistician pop in here and talk about confidence levels too. Just because the average is 1 in 300M for a fatal crash, that doesn't mean that by driving 300M miles with no crash means that we're safer. That's like flipping a coin where tails = fatality. If you flip it twice and both come up heads, that just means you got lucky.
I am not a statistician but I've had enough stats classes to know that there should be a "all other things equal" somewhere in your statement. :-)
No, but if any of them md5'd it they would have caught it.
Assuming they didn't get the MD5 from the same site.
How would you know which md5 hash was correct?
OK, maybe I'm paranoid, but I usually get the download file and the MD5 from separate sources. Ideally the MD5 is from the home site of the project rather than one of its mirrors.
725,000 representative miles
I hope by "representative" they mean diverse traffic and road conditions that represents the various things that a driver will experience over their driving career.
While on this thought I don't expect self-driving vehicles to be universally permitted. There will probably be limitations on the conditions under which an automated driving mode may be used.
As a side note, I believe the FAA adopted a statistical approach to safety regarding civilian space flight. That space flight should be no more hazardous than early commercial airline travel, I think the 1920s was used a baseline. Well at least that was the tentative plan at some point according to a presentation from some folks up at Mohave Spaceport.
... does what its programming tells it to do, avoid hitting other vehicles ...
Its a bit of an assumption to believe that the driving software has that single goal. Staying on the road seems to be something the software is already considering. I wouldn't be surprised if existing software already has "prepare for crash" code that tightens seat belts, unlocks doors, ... maybe even sends an "oh shit" text message to the road side assistance service.
... for once, we all should be thankful for our lawmakers' inability to act ...
Only once? While gov't does occasionally get things right, getting it wrong is hardly a rare instance.
Think about how often gov't gets it wrong with respect to tech issues. The truth is they get it wrong just as often in other domains as well. We merely don't understand those other domains so we don't see the problems, we read some news article and all we see is legislation with good intentions. I'm sure some non-techie is reading an article about gov't going to increase cybersecurity and is thinking "sounds like a good idea".
IMHO we in the U.S. are judging our politicians too often by their good intentions rather than their actual performance, and politicians have adapted to this environment accordingly. All they really care about is that they hold the "correct" stand on an issue, not actually accomplishing anything. Until we start voting out people because they supported well intended but poorly thought out legislation little will change.
My original point has nothing to do with how one implement's the needed assembly code. My point is that there are situations where the programmer has knowledge that can not be communicated to the compiler, knowledge that allows the assembly language programmer to generated better code than the compiler could.
Using stand-alone assembly means that the compiler has to create an entire call frame and ensure that all caller-safe registers are preserved, even if your asm code doesn't touch any of them.
No. The responsibility to preserve registers is the assembly language programmer's and is done in the stand alone assembly. The compiler does not know a function is implemented in assembly. All the compiler ever sees is a prototype of a function in a header, it has no idea if that function is implemented in a separate C file or a separate assembly file.
Using inline assembly is a bit better, but the compiler still often has to treat your asm as a full barrier and so can't reorder operations around it to make most efficient use of the pipeline.
No inline is not necessarily better. The preamble/postamble code may be too aggressive.
The compiler leaving instruction ordering alone is a *good* thing. That is one of the point's of assembly, the human programmer can sometimes do a better job at pipeline management.
Using intrinsics means that the register allocator and instruction scheduler are entirely free to make any changes that they need to, as long as the end result is the same.
And as I said before intrinsics are sometimes the best way to implement a line or two of assembly.
The proper syntax for that is (using x64 types) something like:
int a,b,z;
z = (int)(((long long)a * b) >> 32);
I'm assuming int is 32bit and long long is 64. Even though a is promoted to a larger type and also b, good compilers know that the upper half of those promoted variables are not relevant. They will then use the 32bit multiply, shift the 64bit result and store the part you need.
Admittedly its been a while since I did fixed point but back in the day when I checked popular 32-bit x86 compilers (MS and gcc) they did not generate the couple of instructions that an assembly language programmer would. My example may be dated.
It's very different. Clearly you haven't done significant amount of work with the two to be able to tell.
That is a very bad guess on your part. Intel x86 and PowerPC assembly were a specialty of mine for many years. Whether I was writing a larger function in a standalone .asm file, doing a smaller function or a moderate number of lines as inline assembly in C/C++ code, or only need a line or two of assembly that could be implemented via a compiler intrinsic hardly matters. I was thinking and programming as an assembly programmer not a C/C++ programmer. Standalone .asm, inline assembly or intrinsic are just implementation details; each having their appropriate time and place.
it is vastly different since you leave register allocation to the compiler, which means you can still use inlining and constant propagation.
An alternative with an advantage but still fundamentally programming at the architecture specific assembly level rather than the C/C++ level.
You don't need to use assembly for this, you can just use built-ins or intrinsics. Assembly is only useful if you want to control register usage.
Which are really just alternative ways to write a line or two of assembly code. They are just conveniences, you are still leaving the C/C++ language and dropping into architecture specific assembly.
...companies thinking in the long run prefer an intelligent or well-trained workforce to automation and minimum wage.
In general your point does have some merit but it really does depend on the specific task at hand. My grandfather was a master welder. However for *some* of the tasks that he used to perform a robotic welding system would be a better idea.
The question I have is how it's less expensive (in the long run) to lay a chip out by hand once instead of improving your VLSI layout software forever. NP classification notwithstanding.
Coding in assembly still remains a superior method of squeezing extra performance out of software. It's just that few people do it because compilers are "good enough" at guessing which optimizations to apply, and where, and usually development costs are the primary concern for software development. But when you're shipping hundreds of millions of units of hardware, and you're trying to pack as much processing power in a small and efficient form factor, you don't go with VLSI for the same reason you don't go with a compiler for realtime code: You need that extra few percent.
I like to view things as a little more complicated than just applying optimizations. IMHO assembly gets some of its biggest wins when the human programmer has information that can't quite be expressed in the programming language. Specifically I recall such things in the bad old days when games and graphics code would use fixed point math. The programmer knew the goal was to multiply two 32-bit values, get a 64-bit result and right shift that result back down to 32 bits. The Intel assembly programmer knew this could be done in a single instruction. However there wasn't any real way to convey the bit twiddling details of this fixed point multiply to a C compiler so that it could do a comparable operation. C code could do the calculation but it needed to multiply two 64-bit operands to get the 64-bit result.
Beer isn't a standard thing. Not even close.
And that is why economists prefer the McDonalds Big Mac for currency comparisons. :-)
Seriously, economists do have a Big Mac Index.
There's one purpose for alcohol, and Vodka tends to accomplish that faster and with less vomiting and hangovers. So I'll raise my glass, which is cheaper here than anywhere else, and toast Vodka's awesomeness.
There are at least three practical purposes. Add disinfectant to the list, also add fuel / fire starter when the proof gets above (80?). Obviously these are not the intended purposes but Vodka has been used in these ways when the circumstances warranted.
The following explanation has been attempted in many armies over many years:
"Sir, that is not a still. That is an apparatus creating field expedient disinfectant for the doctors/medics/corpsmen, sir."
Development, for starters.
Which part in the iPhone 5 or iPhone 4(S) develop, for starters?
For one, the CPU. From wiki:
"The A6 is said to use a 1.2 GHz[3][4][5] custom Apple-designed ARMv7 based dual core CPU,[1] rather than standard cores like in previous designs, and an integrated triple core SGX 543MP3[6] graphics processing unit (GPU) with the same performance as the previous Apple A5X processor found in the third-generation iPad. The SGX 543MP3 is running at 266MHz."
Software development has costs too. Even FOSS software has paid developers at times, the success of some FOSS projects has been tied to this fact.
Is that a lot of CSci depts (particularly at community colleges and other places that have associate's degrees) across the country have received grant money from Microsoft itself. That will, of course, make it much more difficult for you to convince them to stop "teaching" Microsoft Office.
That plus the fact that many students *want* to be using the tools that are used in the workplace. As long as MS Office dominates the workplace many students will want to use it in college.
The same is true for operating systems to a degree. During the 90s at a state university it was a common request that more classes allow assignments be done is a MS Windows environment. Many students wanted to do their projects using the same operating system and development tools as was commonly used in industry.
For a modern incarnation of this tendency look at the popularity of iOS programing classes at places like Stanford.
These are university courses.
If there is no interaction with a professor and fellow students then these are not very good university courses.
There is actually little that is new here, one way presentation of information are centuries old, that is what books are.
Yes there are people that can learn from such presentations. However those individuals are exceptionally rare. That is why Universities evolved, because books alone were not enough.
You don't learn anything useful by having someone tell you the 'right answer' to a made-up problem.
And that *is not* what happens in real university level classes.
The point of the problems is to learn to think about the issues and build the skills needed to find answers.
And that *is* what happens in real university level classes. Sadly however that is not what happens in all university/college classes. Yet it happens far more often than when merely reading or engaging in some other one way presentation. By "real" I was not referring to a class that merely takes place on a university/college campus, some classes are good, some are not, it has a lot to do with the professor and/or TA.
Study groups are places where students can help each other build these skills. Even in face-to-face tutorials, a good TA doesn't just tell students the answers, but helps them find their own ways to the answers.
Absolutely.
I'd fathom(sorry) that the strength of a hatch is proportional to the inverse cube of its linear size; two powers for the force (P = F/A hence F = PA) and another for the leverage caused by the distance from the hinge. A submersible drone carrier could well be quite feasible; bear in mind that there already has to be a hatch at least a meter in diameter for the crew to enter.
I believe the dry deck shelters mounted on submarines to launch and recover swimmers and vehicles are close to 3 meters in diameter.
Does *nobody* RTFA anymore? It is an Android vulnerability. They used NFC as one of several ways to exploit it. They could have done the whole thing without using NFC at all.
You are actually supporting my suggestion that NFC is the real subject. An Android vulnerability is found, not exactly big news. That NFC can be the exploit vector, that is new and different.