Please create an account to participate in the Slashdot moderation system


Forgot your password?
What's the story with these ads on Slashdot? Check out our new blog post to find out. ×

Comment ICBMs are how fast? (Score 1) 93

We've got a pretty bad record so far at attempting to intercept objects moving at delta Vs approaching orbital velocities (which 10km/s is definitely that). That's using a guided projectile to attempt the intercept, and counting intercept as close enough to damage via explosive charge. Based on that I can't see us firing a tethered harpoon containing no guidance or propulsion engines, and having any expectation at all of hitting something moving that fast. And that's not even considering the question of actually attaching to the object.

Comment Re:Says Google (Score 1) 437

While I agree that there's bias in the reporting here, in all cases the driver of the "autonomous" car has not been cited as at fault. Thus they are certainly within the definition to say the software wasn't at fault. I am with you in one respect: All of the data should be made public on every incident, and on any close calls where actions of any outside agent (the driver of the "autonomous car" or one in a nearby car) prevented an incident. Unfortunately it's not in Google's interest to do so, and there are no laws mandating it, so it probably won't happen.

Comment Re: What about speeding / useing the center of the (Score 2) 437

So is Google going to pay my speeding ticket when a cop pulls over my autonomous automobile for speeding?

Almost certainly. Though they will bring in several well-respected highway safety engineers to testify that following the flow of traffic is significantly safer than following the posted speed limit. Enough jurisdictions will lose money arguing these cases that there won't be money to be made by writing the tickets. Absent both the financial and safety benefits the police will stop issuing the citations.

Comment Re:Software error ... (Score 1) 234

Mostly I'd agree, but there are a few exceptions:

1) no recursion. Except perhaps forms of tail recursion known to exit in bounded time. But you definitely have to ask yourself why you are doing something that could either be unrolled into a loop or has some kind of exponential growth potential.

2) Local variables are fine so long as the analysis is done to guarantee the maximum stack requirement is pre-committed. I mean, realistically the return pointer is a stack variable, so just calling a function that returns would violate the "no local variables" rule. I wouldn't allow dynamically sized items, because then bugs might cause stack overflows...

3) I agree that malloc and free are forbidden *during real-time operation*. However, in some situations you use dynamic allocation if you can pre-allocate all necessary elements prior to entering operational states. This really depends on whether your system *has* a pre-operational state,

Comment Re:Software error ... (Score 4, Informative) 234

Professionals make mistakes. Garbage collection is a useful tool to make it more difficult to screw up.

I get this. And as a software engineer I fully agree. However, in practical terms, there shouldn't be any dynamic memory management happening at all.

It's a real-time system. It *must* interact, on time, with all the planes that are in it's domain. That should be a bounded, predictable load, or there's no way to guarantee responsiveness. Given that, an analysis should have been done on the maximum number of elements the system supported. Those elements should have been preallocated (into a pool if you want to treat them "dynamically") before actual operation began. If/When the pool allocator ran out of items it should do two things: allocate (dynamically) more, and scream bloody murder to everyone who would listen regarding the unexpected allocation.

This is (one of) the reason(s) I generally haven't liked garbage collected languages for real time systems. There's rarely ever a way to guard against unexpected allocations, because *every* allocation is blind.

Comment Re:Yes, it's not new (Score 1) 268

I'm a software engineer who focuses on automating manufacturing equipment. I've been hearing bad stories about Amazon for at least ten years now. About a year ago I got a call from a head-hunter about a job opening dealing with autonomous warehousing and order fulfillment that sounded like a dream job. Five minutes on the phone got me the name of the company (Kiva Systems) and two minutes of google told me they were being purchased by Amazon.

Nope. Hard stop. I don't even need to know how much they are offering. I love what I do, and I won't willing work for someone who risks making me hate it. Go ruin someone else's psyche. I'd be *really* interested to know how many people there are just like me.

Comment Re: Meet the new guy (Score 1) 393

There are continuous claims that voting is ineffective because "my vote doesn't count" when it is because someone is voting for a losing candidate...

As a person squarely in the "my vote doesn't count" category, I feel compelled to say that it isn't that the candidate I'd vote for can't win, it's that no one I'd want vote for could ever possibly win. There is no possible way for me to vote in any way that both A) represents my beliefs and B) adds support to the least bad alternative. It really has nothing to do with diluting my vote. My vote would never be in the top five parties in the USA, much less the top two. I'll never be represented any way other than badly. Mostly that's ok because I just don't care that much.

...why should we dilute the vote even further by letting everyone who walks into the polling place vote? Why SHOULDN'T voting be reserved for citizens?

If the government let them in, they should have a voice. They are subject to the penalties and restrictions but not the benefits? That is treating them as second class humans, which I'm pretty vocally opposed to. Illegals are more complex, but given how little we actually spend enforcing those rules (in 2013 we deported less than 5% of the estimated illegal population) we seem complicit in their presence here. Given that I find it hard to argue they shouldn't be afforded representation on the same grounds. In my mind representative governance is a human right, rather than a right granted by citizenship.

But I'm pretty well not in the there's that.

Comment Re:Winter? (Score 1) 231

Ain't nothing going to happen with autonomous vehicles until they solve the rain and snow problem. Maybe California doesn't have to worry about vehicles in precipitation, but the rest of the nation does.

I see this complaint every time an autonomous car story comes up. Is there actual evidence somewhere that rain and snow have any significant impact on the vehicles' ability to perceive an environment or on their ability to navigate it? The sensor fusion algorithms already deal with noise exclusion and transitory sensing failures. I can believe heavy snow which obscures the lane markings would be an issue, but even then that doesn't really prevent collision avoidance, or even safe driving ability so long as there's always to option to just go slower. The rules of traffic interactions in the absence of lane markings are pretty well defined, and are mostly just "do what boats do".

Comment Re:How do they fare in colder climates? (Score 1) 904

They lose some range in extreme cold and hot temperature ranges. In cold weather much of that difference is purely in keeping the temperature of the cabin and battery heated to optimal levels. It is suggested that you preheat your vehicle from grid electricity before driving to maximize range (implying plugging it in while you're at work I guess). It is also recommended that you use seat and steering wheel heaters because they more directly reach the passengers, allowing the cabin air to be maintained at a slightly lower temperature.

Comment Re:I sure don't want my co-workers to know my sala (Score 1) 430

You are totally missing out on an opportunity to lord your success over your peers. You should feel free to call them minions or vassals; Also, I whole-heartedly recommend using the salary information in your next meeting. "Well, George, from the look of things I make almost twice what you do. Apparently no one who matters actually cares what you think, so STFU."

Winning friends and influencing people through transparency...

Comment Re:How did it react during the accident? (Score 1) 549

Hmm. I get what you are saying, but I'm not down with your analysis. There will be a certain amount of energy transferred by the impact. The injurious portion of that impact is during the impulse strike of the two cars. Crumple zones, for instance, work by spreading the impulse experienced by the cabin across a larger time. If some of that same energy goes into accelerating the car and then being dissipated later by braking all that is doing is spreading the total energy dissipation across a larger time window. It should lower the impulse transferred to the cabin by using some of the energy to accelerate the rest of the frame as well.yes, you get slightly more acceleration due to the whole car accelerating, but less total impulse due to the partitioning of the energy transfer.

Not that I think there's any significant difference, since in any serious rear end collision the total acceleration will vastly overwhelm the strength of your legs to press the brake pedal.

Comment Re:Exchanging insurance information (Score 1) 549

Right about average. The average US driver drives 13.476 miles per year and goes an average of 10 years between accidents.

Well, the reported accidents at least. Show me the numbers on how many people get into little fender benders that never get reported so we can compare some real data.

Comment Re:Avoidable? (Score 1) 549

And it is supposed to do all of that in a split second.

You sir are an idiot.

No way. It's supposed to do that for every car within 300 feet all the time on the off chance one of them is about to cause a problem. Think of the children! Google pinkie-swears they won't do anything bad with the new datastream this represents. Also, there's a Starbuck's we think you'd like on your route to work...

panic: kernel trap (ignored)