The new version only knows that the base station exists if it crosses in the path of the IR beam from said station -- same way it knows to avoid the invisible walls (different modulation, I would assume, for the base station). So, it will only 'see' the station and return to it if it is in front of and within about 15 feet of the base station, or manages to cross said area during its 'seek home' routine.
Which for most people probably works great. Large rooms or multiple room Roomba users need not apply.
Not saying I'm not happy with it! Bloody great device for those living in the desert SW -- sand seems to reproduce on the floor, even with doors and windows closed.
You do not use single letter variables in libraries. Period. Ever. Read some C libraries; you prefix vars with screwy chars. Double underscore is a common choice.
If there *are* single letter vars in your library, you REPLACE them with something else. It is easy to do, and QC should ALWAYS catch crap like that.
You should not have faith in the quality of matlab code. If you ever built something expensive based on an unverified simulation that was given by MATLAB you would be fired. I did not have one professor that believed MATLAB was good -- it was simply acceptable at a broad range of things, and was available to them already. And the University wasn't about to fork over more bucks for a bunch of different software packages for each department.
Sorry. Rant mode off. MATLAB cost me far more time than it ever saved me. There are many cases where the reverse is true. The *idea* is sound. The company blows. I am very glad there are open-source alternatives that are rapidly gaining ground:~).
*ADD FEATURES* to Octave. Which already has much of the basics. Not rewrite MATLAB.
Which, really, on a lab-by-lab basis (in that one lab generally will use only 'n' features) you probably COULD rewrite all the code you needed with one or two full time developers.
In 3 years of aerospace engineering classes, I used maybe 10 'special' functions of MATLAB; 4 of which were the ODE related. The rest was 'just math'.
Do we get rewarded for showing how crappy MATLABs code is?
For instance, their use of the single letter global variable (g, I believe it was) in one (or more) of their ODE solvers?
beh. MATLAB is like crack; as soon as you start using it you know you should take the time to find a *real* solution to your problems... but really, it is far easier to continue on down the path you are on...
No offence meant to the uber geniuses who create the algorithms. But that wouldn't generally be the folks at MATLAB, and when so, they (I hope) aren't the guys making it into crap code.
yeah, but high temperatures aren't a problem on the moon. I would imagine that creating a furnace with >3000K temps would take, what, 10 meters of mirrors?
Turn that sh^t into plasma and seperate it magnetically. Or not.;~)
Extracting O2 from soil is done all the time on Earth, we just tend to treat the oxygen as an unnecessary byproduct while we keep the useful things (e.g. most metals);
And on this contest it sounds like the byproducts will be aluminium and silicon... and those will be discarded. Which is why I think the contest is poorly worded, and will lead to an inferior 'winning entry'.
Why throw away ultra pure silicon and aluminium just to get oxygen? With a slight increase in complexity you get a sweet refinery that can produce O2, Si and Al, as well as iron and titanium in much smaller quantities.
Sample rock break down, I figure this is *fairly* representative, but I just picked a random rock from the below link (by weight %):
SiO2 - 44.94 Al2O3 - 35.71 CaO - 20.57 Na2O - 0.384 MgO - 0.53 Fe - 0.2 Ti - 0.018
I was going to say something similar; however I did know that the engine does pivot. It does so to provide additional lift and vector control (otherwise the plane woudl be 'balancing on a point' so to speak).
The vast majority of the lift comes from the lifting fan; nice, cold gas. The engine thrust-gas is routed through ductwork and the main nozzle pivots to provide stability and direction control; each wing has a small nozzle for this purpose.
If I recall correctly, the HOT gasses are not used, or are mixed well enough with cold air that fire is not a concern. (this and the lifting fan are points for the grandparent;~) )
But then, Boeing said that THEIR version wouldn't choke to death on its own exhaust.... WHUPS! Guess they were wrong!
So what's your opinion on the collision avoidance system that was tested a few years back on (IIRC) an F/A 18?
The one that the test pilot went into a hands free vertical dive at over 400mph? To see if the computer would indeed pull away at the very last possible moment (e.g. too late for said pilot to save his own ass)?
Yeah, I recal something like a snap-roll and a better than 9.5G pull out.
Autopilots get the hell tested out of them. Not because it saves human lives (hahahahhaa.... sorry), but because planes are really expensive -- and in this case, so is whatever it is landing on.
If an M16 jams and a solder dies... well, you get get another of each, purty quick.
carat (ct or c) [1] a unit of mass used for diamonds and other precious stones. Originally spelled karat, the word comes from the Greek keration, a carob bean; carob beans were used as standards of weight and length in ancient Greece in much the same way barleycorns were used in old England. Traditionally the carat was equal to 4 grains. The definition of the grain differed from one country to another, but typically it was about 50 milligrams and thus the carat was about 200 milligrams. In the U. S. and Britian, the diamond carat was formerly defined by law to be 3.2 troy grains, which is about 207 milligrams. Jewelers everywhere now use a metric carat defined in 1907 to be exactly 200 milligrams.
It is Tritium. It is not a significant source of power. I would be surprised if this thing produces even a watt. The article is *very* thin on details, but I am going to wager that this is for *incredibly* lower power draw long term applications... such as smoke alarms and other 'standby' sensors.
However, yes; I know quite a bit about nuclear power, and if the sucker produced that much power then it *could* melt itself down and it WOULDN'T be the safe power source they are claiming it is. Err.. well, it would melt -- the escaped tritium wouldn't be a real hazard, but the heat and potential for fire would be a hazard! Don't want to imply a runaway nuclear catastrophe here -- but melt-down is the correct (if loaded) term: you would be left with a pile of slag;~)
Anyway... Yeah. I concede the point to you: If this device produces more than a few watts, no, it couldn't be easily shut off. However, I'm voting for 1 to 3 watts max. Probably more like a tenth of a watt. I think if the battery is not *in* a device then the battery itself would warm up a few degrees and disipate the excess energy that way.
Even if they do create the potential to have more than a few watts, I would wager that the design would require that the battery could disipate its own waste heat via passive methods. Active methods can fail, and given large numbers of something that can fail, at least one will. And Dell already knows all about recalling batteries and power-supplies that melt stuff;~)
The survivability would be related to the fact that the explosions tend to happen on the way up or down; as opposed to while at cruising altitude.
You don't live if you have explosive decomp at 40K feet. If there is a slow drop to ambient, maybe -- like a cargo door cracking open but not flying off. You will, however, pass out VERY quickly, so it isn't like you will care for long;~)
But hey! If you manage to get your ox mask and stay concious, the pure O2 will help pacify you anyway! Good to go either way;~)
When the Comets [square window planes] blew up they usually didn't find much in the way of large pieces... of anything. True, that was the entire airplane unzipping... but being near a door that goes missing in a modern airliner would be similar.
When you are PLANNING your code, no. There is little difference between calling a function in a huge ass linear execution procedural language and calling a function in another object from the perspective of how you think
You can write code in C that 'executes' in a fairly object-oriented way, if you choose. You can write non-object oriented code in C++, if you choose.
My point is NOT that the languages are anything CLOSE to one another in the area of what you type to get 'x' to happen; my point is that the conceptualization is very similar. However, having worked with all three, I would say they are so close to each other as to be irrelevant. However, this is with comparisons to Visual Basic, FORTRAN (77,2000), MatLab and LISP, as well as scripting languages.
Anyway, I'm not violent about any of it:~) Just saying: it is easy to learn new languages. And if you can code in Java, you would have to be a fairly poor code monkey to not be able to pick up C++ in a few weeks. You'd probably still suck at some rather basic stuff, but you would be able to get what needed to be done, done. Just not nearly as efficiently or as fast as a coder that has been working in C++ for a year. Or 5.
Yes you can. Also, yes it does -- if the company is looking for long term employees (caveat, they have to KNOW you don't actually know the language upon hiring you! No lying;~) ).
If you are a GOOD programmer in any language, you will be an okay programmer in any other language you choose to learn within 'a few' (3-6) weeks.
I would go so far as to consider this the definition of a good programmer.
It would take me at least half an hour to list all the languages I've learned and discarded; not that the list is THAT long, but simply to dredge through my memory! Logic is common to all languages. The reason people hate LISP (and love it) is because you have to change your thought patterns to use it well. C++ and C are 95% similar in terms of how you think when spewing code out your fingertips.
I do live in SoCal. Looks fine here to me. I am certain the area I am in has significantly higher (per capita) illegal immegrant population than does San Diego.
Why don't you read a few economic texts that deal with, oh, say, labor costs and the economy? In particular, why don't you pay attention to what percent of farming costs are related to labor?
15 billion dollars is not even a percent of what illegal immigrants have contributed to the American economy by taking jobs that would have either not been taken, or would have required unreasonable wages to convince an american to take (10-12 dollars/hr is not reasonable for zero skill labor). Does it create local problems? Sure. So does urban poverty. Grow up. San Diego bitching about... jesus. Go live in Gary IN and get back to us in a year.
Slashdot Mirror
A lot of replies say that #2 has been fixed.
They have small rooms.
The new version only knows that the base station exists if it crosses in the path of the IR beam from said station -- same way it knows to avoid the invisible walls (different modulation, I would assume, for the base station). So, it will only 'see' the station and return to it if it is in front of and within about 15 feet of the base station, or manages to cross said area during its 'seek home' routine.
Which for most people probably works great. Large rooms or multiple room Roomba users need not apply.
Not saying I'm not happy with it! Bloody great device for those living in the desert SW -- sand seems to reproduce on the floor, even with doors and windows closed.
Cheers,
... where's Rosie when you need her?
You do not use single letter variables in libraries. Period. Ever. Read some C libraries; you prefix vars with screwy chars. Double underscore is a common choice.
:~).
If there *are* single letter vars in your library, you REPLACE them with something else. It is easy to do, and QC should ALWAYS catch crap like that.
You should not have faith in the quality of matlab code. If you ever built something expensive based on an unverified simulation that was given by MATLAB you would be fired. I did not have one professor that believed MATLAB was good -- it was simply acceptable at a broad range of things, and was available to them already. And the University wasn't about to fork over more bucks for a bunch of different software packages for each department.
Sorry. Rant mode off. MATLAB cost me far more time than it ever saved me. There are many cases where the reverse is true. The *idea* is sound. The company blows. I am very glad there are open-source alternatives that are rapidly gaining ground
Your sig suddenly makes *so* much more sense... ;~)
*Kidding! Joke! No offense! I do hate MATLAB with a passion, but you are also right.
read. then reply.
*ADD FEATURES* to Octave. Which already has much of the basics. Not rewrite MATLAB.
Which, really, on a lab-by-lab basis (in that one lab generally will use only 'n' features) you probably COULD rewrite all the code you needed with one or two full time developers.
In 3 years of aerospace engineering classes, I used maybe 10 'special' functions of MATLAB; 4 of which were the ODE related. The rest was 'just math'.
Do we get rewarded for showing how crappy MATLABs code is?
For instance, their use of the single letter global variable (g, I believe it was) in one (or more) of their ODE solvers?
beh. MATLAB is like crack; as soon as you start using it you know you should take the time to find a *real* solution to your problems... but really, it is far easier to continue on down the path you are on...
No offence meant to the uber geniuses who create the algorithms. But that wouldn't generally be the folks at MATLAB, and when so, they (I hope) aren't the guys making it into crap code.
Coolness. I thought about it but ADD sent me on to other things :~)
;~)
As to yield: I'm guessing it doesn't matter much... there is rather a lot of moon rock available
yeah, but high temperatures aren't a problem on the moon. I would imagine that creating a furnace with >3000K temps would take, what, 10 meters of mirrors?
;~)
Turn that sh^t into plasma and seperate it magnetically. Or not.
Extracting O2 from soil is done all the time on Earth, we just tend to treat the oxygen as an unnecessary byproduct while we keep the useful things (e.g. most metals);
/ index.htm
And on this contest it sounds like the byproducts will be aluminium and silicon... and those will be discarded. Which is why I think the contest is poorly worded, and will lead to an inferior 'winning entry'.
Why throw away ultra pure silicon and aluminium just to get oxygen? With a slight increase in complexity you get a sweet refinery that can produce O2, Si and Al, as well as iron and titanium in much smaller quantities.
Sample rock break down, I figure this is *fairly* representative, but I just picked a random rock from the below link (by weight %):
SiO2 - 44.94
Al2O3 - 35.71
CaO - 20.57
Na2O - 0.384
MgO - 0.53
Fe - 0.2
Ti - 0.018
Here is a page on the moon rock samples:
http://www-curator.jsc.nasa.gov/curator/lunar/lsc
Each link is a PDF which contains, amoung other things, a breakdown of the mineral composition of the rock in question.
I was going to say something similar; however I did know that the engine does pivot. It does so to provide additional lift and vector control (otherwise the plane woudl be 'balancing on a point' so to speak).
;~) )
The vast majority of the lift comes from the lifting fan; nice, cold gas. The engine thrust-gas is routed through ductwork and the main nozzle pivots to provide stability and direction control; each wing has a small nozzle for this purpose.
If I recall correctly, the HOT gasses are not used, or are mixed well enough with cold air that fire is not a concern. (this and the lifting fan are points for the grandparent
But then, Boeing said that THEIR version wouldn't choke to death on its own exhaust.... WHUPS! Guess they were wrong!
You have been watching 'Airplane' again, haven't you?
;~) Could have been someother movie.
Least-wise, I think that is the only place Ive ever seen side mirrors mounted on a fighter
Uhm... no.
'Normal' aircraft landing systems are designed to allow you to hit the ground as if dropped (literally) from 3 meters.
Aicraft carriors its 6 meters. Or maybe it was 9m. Anyway. 10 cm is fricking nothing at all.
I am curious what you think could happen if the system screws up by less than 4".
So what's your opinion on the collision avoidance system that was tested a few years back on (IIRC) an F/A 18?
The one that the test pilot went into a hands free vertical dive at over 400mph? To see if the computer would indeed pull away at the very last possible moment (e.g. too late for said pilot to save his own ass)?
Yeah, I recal something like a snap-roll and a better than 9.5G pull out.
Autopilots get the hell tested out of them. Not because it saves human lives (hahahahhaa.... sorry), but because planes are really expensive -- and in this case, so is whatever it is landing on.
If an M16 jams and a solder dies... well, you get get another of each, purty quick.
Yes. I'm cynical.
Hmm.
:~)
Braking power, mathematically, has absolutely NOTHING to do with surface area. It is all friction and pressure. Can't remember the equation off hand.
The proportional valve thing never occured to me though. Makes sense
Cheers,
But the price has been set in part because of the wars over diamonds... and the diamond cartels death grip on the diamond markets.
t m
Diamonds were considered too worthless to give as an engagement ring until sometime in the early 1900s.
Great link with plenty of references:
http://www.fguide.org/Bulletin/conflictdiamonds.h
From
http://www.unc.edu/~rowlett/units/dictC.html
Drum brakes don't hold under power. Only disk. Hence why 'power braking' works on drum brakes and not disc.
It is Tritium. It is not a significant source of power. I would be surprised if this thing produces even a watt. The article is *very* thin on details, but I am going to wager that this is for *incredibly* lower power draw long term applications... such as smoke alarms and other 'standby' sensors.
;~)
;~)
:~)
However, yes; I know quite a bit about nuclear power, and if the sucker produced that much power then it *could* melt itself down and it WOULDN'T be the safe power source they are claiming it is. Err.. well, it would melt -- the escaped tritium wouldn't be a real hazard, but the heat and potential for fire would be a hazard! Don't want to imply a runaway nuclear catastrophe here -- but melt-down is the correct (if loaded) term: you would be left with a pile of slag
Anyway... Yeah. I concede the point to you: If this device produces more than a few watts, no, it couldn't be easily shut off. However, I'm voting for 1 to 3 watts max. Probably more like a tenth of a watt. I think if the battery is not *in* a device then the battery itself would warm up a few degrees and disipate the excess energy that way.
Even if they do create the potential to have more than a few watts, I would wager that the design would require that the battery could disipate its own waste heat via passive methods. Active methods can fail, and given large numbers of something that can fail, at least one will. And Dell already knows all about recalling batteries and power-supplies that melt stuff
Cheers
No. Excess energy would have to be expended in some form or another.
eh? How about just putting a cover over the radiation source?
This isn't uranium or plutonium; it won't melt-down if you don't use the generated particles!
Cheers,
The survivability would be related to the fact that the explosions tend to happen on the way up or down; as opposed to while at cruising altitude.
;~)
;~)
You don't live if you have explosive decomp at 40K feet. If there is a slow drop to ambient, maybe -- like a cargo door cracking open but not flying off. You will, however, pass out VERY quickly, so it isn't like you will care for long
But hey! If you manage to get your ox mask and stay concious, the pure O2 will help pacify you anyway! Good to go either way
When the Comets [square window planes] blew up they usually didn't find much in the way of large pieces... of anything. True, that was the entire airplane unzipping... but being near a door that goes missing in a modern airliner would be similar.
When you are writing code, yes.
:~) Just saying: it is easy to learn new languages. And if you can code in Java, you would have to be a fairly poor code monkey to not be able to pick up C++ in a few weeks. You'd probably still suck at some rather basic stuff, but you would be able to get what needed to be done, done. Just not nearly as efficiently or as fast as a coder that has been working in C++ for a year. Or 5.
When you are PLANNING your code, no. There is little difference between calling a function in a huge ass linear execution procedural language and calling a function in another object from the perspective of how you think
You can write code in C that 'executes' in a fairly object-oriented way, if you choose. You can write non-object oriented code in C++, if you choose.
My point is NOT that the languages are anything CLOSE to one another in the area of what you type to get 'x' to happen; my point is that the conceptualization is very similar. However, having worked with all three, I would say they are so close to each other as to be irrelevant. However, this is with comparisons to Visual Basic, FORTRAN (77,2000), MatLab and LISP, as well as scripting languages.
Anyway, I'm not violent about any of it
Yes you can. Also, yes it does -- if the company is looking for long term employees (caveat, they have to KNOW you don't actually know the language upon hiring you! No lying ;~) ).
If you are a GOOD programmer in any language, you will be an okay programmer in any other language you choose to learn within 'a few' (3-6) weeks.
I would go so far as to consider this the definition of a good programmer.
It would take me at least half an hour to list all the languages I've learned and discarded; not that the list is THAT long, but simply to dredge through my memory! Logic is common to all languages. The reason people hate LISP (and love it) is because you have to change your thought patterns to use it well. C++ and C are 95% similar in terms of how you think when spewing code out your fingertips.
It's no small feat to be able to *properly* implement software designs or infrastructures (any goober can do it wrong or insecurely)
Oh no. I know plenty of goobers that can't do it at all
I don't know why Gates isn't lining up behind Bush on this; ;~)
It's harder to apply the LART when they are so far away.
So where did your family emigrate from? When?
I am tired of short-sited, hypocritical idiots.
I do live in SoCal. Looks fine here to me. I am certain the area I am in has significantly higher (per capita) illegal immegrant population than does San Diego.
Why don't you read a few economic texts that deal with, oh, say, labor costs and the economy? In particular, why don't you pay attention to what percent of farming costs are related to labor?
15 billion dollars is not even a percent of what illegal immigrants have contributed to the American economy by taking jobs that would have either not been taken, or would have required unreasonable wages to convince an american to take (10-12 dollars/hr is not reasonable for zero skill labor). Does it create local problems? Sure. So does urban poverty. Grow up. San Diego bitching about... jesus. Go live in Gary IN and get back to us in a year.