Seems to me, they have not yet tuned the control system. This thing may be inherently very unstable...
Of course this kind of propulsion, as in helicopters, benefits from the proximity of the ground, but I guess this one can get higher than what is shown at the video. But, heh, power without control is almost nothing....
The value a professor should transmit to their students is much more than following certain program for certain subject. Think integral!.
Students are sometimes busy and don't like working aside the established program. I understand that. But let me state that ignoring these extra works you lose opportunities to gather knowledge which can be good for your personal formation and which can feed your resume as well.
Workarrounding your teacher requirements is a good point also, because you react an adapt instead of crying and complaining. Just hope you don't always do that way...
I was pissed off enough that she required us to use a program of her choice to generate a PDF that I simply didn't bother to learn.
Seems you completely misunderstood what she was pretending: my guess is that she wanted you to learn another point of view in the field of documents creation.
I just OO.o, same as always, and exported to PDF. The marker didn't know the difference.
Just because she didn't say anything does not mean she didn't know. She knew most of you would not use LaTeX.
This course I've driven a final career project, and convinced the boy to use LyX (I helped him installing it on windows, which is pretty easy by the way). At the beginning it was tricky for him, but after a couple of days he was comfortable. At the end he recognizes how much work he has avoided respect writing his work on MsOffice.
The point is that his mates were puzzled about how elegant his work looked like. I've been reviewing some of the works and none come close to LaTeX look -further, there are some horrible looking ones-. Ensuring style consistency is pretty hard at tools so elastic as office packages are.
There are plenty of benchmarks that show even GTK apps run faster on the KDE desktop.
Show me.
Seriously, I fail to get the point of such statement. The desktop you are running has little effect on the graphical apps you are running unless
a) You are swapping (because the desktop has loaded so much things and you run out of memory).
b) You are compositing (in such case performance would depend on compositing manager which can be part or not of the desktop).
GTK+, however, is typically slower than other toolkits. GTK+1.x had severe flickering problems (do you people remember?), was very very fast but ugly because of the flickering. The problem could have been addressed by double-buffering the more flickering widgets (labels and buttons) as everyone else does (QT3, windows, QT4?) or disabling hovering (as Motif does, but still flickers at exposures). However, in GTK+2 someone decided to solve the flickering problem from the most fundamental level. As a result, GTK+2 never ever flickers under any condition (*) since everything is double-buffered; but it has of course a penalty on both performance and memory sides. Nevertheless, on modern hardware you almost do not notice these penalties nowadays.
QT4 is an impressive piece of work. Nevertheless, the style used at KDE-4 seems to apply some kind of animations which slow down the list scrolls and so on making it painful at certain circumstances. I've not tested KDE4.1, so perhaps these issues have been solved, but it reminds me the beginning with Gnome-2 and the GTK-2 apps which were very slow at the time because hardware could not cope with the feature of not flickering at the most aggressive circumstances.
(*) It can lag, which certainly does at low network latencies (X11) or when heavy CPU loads or at old machines and/or with poor video drivers.
X is the worst way imaginable to do graphics (a giant frame buffer). Stop trolling about what you don't know about!.
X is not a giant frame buffer. It has vector operations, combined with raster operations.
X11 is a wrong option over high latency links because it is designed to provide a very high performance at low latency ones.
For high latency links, use NX which is much faster than VNC + compression (being VNC a giant frame buffer, is faster than X11 because the latency issues).
NX does compression, but most importantly solves the latency issues by cumulating requests avoiding roundtrips.
As someone has already pointed out, NX does that as well.
Plain X11 + extensions is probably more responsible at low-latency links (LAN). Providing hardware accelerated graphics (OpenGL). IMHO X11 was designed in order to achieve very high performance of apps run at remote expensive servers and displayed at many graphical terminals conected to those. For normal apps you don't realize you are running remotely.
NX is the almost ultimate answer to the needs of remote displaying. If only supported GLX with hardware acceleration it would be just perfect. I expect to see it soon:). The performance of NX over internet links is incredibly fast: not only compresses the X11 protocol (including vector drawing), it also compresses the raster parts (for instance the wallpaper, icons,...) using a JPG-like algorithm whose quality depends on the selected link capabilities. The raster images are cached also.
Installing NX server (the commercial product, free of charge) is very easy at common distros (debs and rpms provided for i386 and amd64 archs).
Free-NX is almost as easy to install.
interesting that this guy is talking to press a lot more: I was a couple of weeks ago in a conference given by him at Barcelona (Spain). He is a nice speaker. He seems at a round of conferences around the world universities showing the CUDA technology. By the way, CUDA technology seems to be an interesting thing.
The SR-71 did fly such M 3. for hours!. X-15 flew only a couple of minutes.
I'm talking about ambient temperature, SR-71 was painted in nearly black color in order to emit as much thermal radiation thus reducing its equilibrium temperature. X-15 did not reach the equilibrium temperature of a M 7.5 flight; which could not withstand.
I had not think the problem this way:P
I was told this when studying fuels, about dropping a match inside a car deposit. There, at a hot day the atmosphere would *potentially* be too rich in gasoline to produce any kind of ignition.
In an open environment, you are right, there is always a zone with the right mixture to produce a combustion
nevertheless, again, do not play with gasoline:-P !!! gasoline is far more flammable than other fuels like alcohol, so the results usually over exceed your experiences. Kids stop playing whit it:P
The SR-71 is one of my all time favorite planes. You are not alone. Seriously, SR-71 was an amazing plane in several aspects. If one has to chose only one plane to be the favourite, there is only one candidate...
You are both right and wrong. I'll try to clarify. The heat transfer between a fluid and a solid wall happens a the viscous zone so called boundary layer, where friction happens. On the other hand, the temperature which modulates this heat transfer is the external flow total temperature which is where viscous effects are negligible.
The total temperature is given by the compressible isentropic flow behaviour:
Tt/Tamb = 1+ (k-1)/k*M^2, where
Tt is the total temperature in K or Rankine,
Tamb is the ambient temperature in same units above,
k is the heat coefficient ratio, for the air is 1.4 and
M is the mach number.
Thus, for a 3.5 Mach number, the maximum for SR-71, the total temperature is:
Tt = Tamb*(1+0.29*3.5^2)=Tamb*4.5,
and for a Tamb of -50 degrees celsius (-58 deg Fahrenheit), becomes,
Tt = 223*4.5=1003K = 730 deg C = 1346 deg F
At that speed, the ambient is sooooo hot! even when the atmosferic temperature may be soo freezing!!!!.
At the leading edge of the SR-71 wings and the fuselage nose, you reach such temperature without any kind of viscous effects; just because you stagnate the flow isentropically there: you are more right than wrong at the end:P
Please don't try it!
Of course, at a very hot day *perhaps* you can do it because there is so much amount of gasoline evaporated that the fuel/oxygen ratio is bigger than the required for a combustion; but do not play ever with gasoline!!!.
But, when you address more than 1gb+something of memory at one executable, the access to that memory becomes much more expensive. Whereas, in 64bit you get full speed addressing!
My experience with numeric code, compiled in 32bit and 64bit is that the same code tends to be about a 15% slower in the 32bit case.
When the code uses more than 1Gb of RAM, the differences are much higher.
The tests where done in a 64bit install with a 32bit chroot (so the kernel was 64bit). The 32bit executable performed exactly under the 32bit chroot or directly on the normal 64bit usage. (the 32bit chroot was used to compile the binary, since it is quite easy to setup)
I'm not sure if at that time I did dual-boot to check the 32bit executable in a 32bit kernel, but I guess I would get the same results: poorer performance of about a 15% when memory usage is directly addressable with 32bit...
Now, 64-bit Ubuntu, OTOH, is completely 64-bit if you don't install any 32-bit libs or applications. And, if you install the 32-bit libs you can run 32-bit software as well which can be handy specially for custom binaries around (old games such quake,...). Older version of Ubuntu (Hardy if I recall correctly) were 64bit unless for OpenOffice which had not yet jumped to the 64bit wagon.
I'm a 64bit Ubuntu user for last two years and a half, and time ago it was trickier to use a 64bit OS, but nowadays is pretty the same to install a 32bit or a 64bit version. And with a 64bit version you can address more RAM, so IMHO it does not make sense to use a 32bit version unless your hardware is too old or you are in a certain production environment.
I don't really know Objective-C, but if you know C, you can get incrementally improving in your knowledge of C++.
C++ is massive, but one can use a subset that full fills her needs.
The closest Linux equivalent would be to say that all software on Linux must use Motif, and that if you want to port to Windows or Mac you must emulate Motif. Close, but not exact. One can use Motif in windows if you install a proper X-server (e.g. cygwin) and compile there either Lesstif or OpenMotif (the last one is illegal -since Windows is not an open operating system but it is OK at Mac-OSX- but I guess you can get a license from the OpenGroup; the first one is already available under cygwin but its no 100% replacement for Motif yet).
Whereas your comment is insightful and your comparison to the eldest Motif is appropriate, it is funny that even in such case there exist a way to make a Motif program run inside a windows box (besides the obvious vmware way).
Slashdot Mirror
Seems to me, they have not yet tuned the control system. This thing may be inherently very unstable...
Of course this kind of propulsion, as in helicopters, benefits from the proximity of the ground, but I guess this one can get higher than what is shown at the video. But, heh, power without control is almost nothing....
This was a database class. Not a business class.
The value a professor should transmit to their students is much more than following certain program for certain subject. Think integral!.
Students are sometimes busy and don't like working aside the established program. I understand that. But let me state that ignoring these extra works you lose opportunities to gather knowledge which can be good for your personal formation and which can feed your resume as well.
Workarrounding your teacher requirements is a good point also, because you react an adapt instead of crying and complaining. Just hope you don't always do that way...
I was pissed off enough that she required us to use a program of her choice to generate a PDF that I simply didn't bother to learn.
Seems you completely misunderstood what she was pretending: my guess is that she wanted you to learn another point of view in the field of documents creation.
I just OO.o, same as always, and exported to PDF. The marker didn't know the difference.
Just because she didn't say anything does not mean she didn't know. She knew most of you would not use LaTeX.
This course I've driven a final career project, and convinced the boy to use LyX (I helped him installing it on windows, which is pretty easy by the way). At the beginning it was tricky for him, but after a couple of days he was comfortable. At the end he recognizes how much work he has avoided respect writing his work on MsOffice.
The point is that his mates were puzzled about how elegant his work looked like. I've been reviewing some of the works and none come close to LaTeX look -further, there are some horrible looking ones-. Ensuring style consistency is pretty hard at tools so elastic as office packages are.
Gentlemen, We are reading a post from Chuck Norris. Of course he is a "niceone", anyone willing to disagree?
There are plenty of benchmarks that show even GTK apps run faster on the KDE desktop.
Show me.
Seriously, I fail to get the point of such statement. The desktop you are running has little effect on the graphical apps you are running unless
a) You are swapping (because the desktop has loaded so much things and you run out of memory).
b) You are compositing (in such case performance would depend on compositing manager which can be part or not of the desktop).
GTK+, however, is typically slower than other toolkits. GTK+1.x had severe flickering problems (do you people remember?), was very very fast but ugly because of the flickering. The problem could have been addressed by double-buffering the more flickering widgets (labels and buttons) as everyone else does (QT3, windows, QT4?) or disabling hovering (as Motif does, but still flickers at exposures). However, in GTK+2 someone decided to solve the flickering problem from the most fundamental level. As a result, GTK+2 never ever flickers under any condition (*) since everything is double-buffered; but it has of course a penalty on both performance and memory sides. Nevertheless, on modern hardware you almost do not notice these penalties nowadays.
QT4 is an impressive piece of work. Nevertheless, the style used at KDE-4 seems to apply some kind of animations which slow down the list scrolls and so on making it painful at certain circumstances. I've not tested KDE4.1, so perhaps these issues have been solved, but it reminds me the beginning with Gnome-2 and the GTK-2 apps which were very slow at the time because hardware could not cope with the feature of not flickering at the most aggressive circumstances.
(*) It can lag, which certainly does at low network latencies (X11) or when heavy CPU loads or at old machines and/or with poor video drivers.
X is not a giant frame buffer. It has vector operations, combined with raster operations.
X11 is a wrong option over high latency links because it is designed to provide a very high performance at low latency ones.
For high latency links, use NX which is much faster than VNC + compression (being VNC a giant frame buffer, is faster than X11 because the latency issues).
NX does compression, but most importantly solves the latency issues by cumulating requests avoiding roundtrips.
As someone has already pointed out, NX does that as well. :). The performance of NX over internet links is incredibly fast: not only compresses the X11 protocol (including vector drawing), it also compresses the raster parts (for instance the wallpaper, icons, ...) using a JPG-like algorithm whose quality depends on the selected link capabilities. The raster images are cached also.
Plain X11 + extensions is probably more responsible at low-latency links (LAN). Providing hardware accelerated graphics (OpenGL). IMHO X11 was designed in order to achieve very high performance of apps run at remote expensive servers and displayed at many graphical terminals conected to those. For normal apps you don't realize you are running remotely.
NX is the almost ultimate answer to the needs of remote displaying. If only supported GLX with hardware acceleration it would be just perfect. I expect to see it soon
Installing NX server (the commercial product, free of charge) is very easy at common distros (debs and rpms provided for i386 and amd64 archs).
Free-NX is almost as easy to install.
Are you willing to get them slashdotted?
Nice if you are a F.C.Barcelona supporter :P
The SR-71 did fly such M 3. for hours!. X-15 flew only a couple of minutes.
I'm talking about ambient temperature, SR-71 was painted in nearly black color in order to emit as much thermal radiation thus reducing its equilibrium temperature. X-15 did not reach the equilibrium temperature of a M 7.5 flight; which could not withstand.
s/deposit r/tank
dammned false-friends
I had not think the problem this way :P :-P !!! gasoline is far more flammable than other fuels like alcohol, so the results usually over exceed your experiences. Kids stop playing whit it :P
I was told this when studying fuels, about dropping a match inside a car deposit. There, at a hot day the atmosphere would *potentially* be too rich in gasoline to produce any kind of ignition.
In an open environment, you are right, there is always a zone with the right mixture to produce a combustion
nevertheless, again, do not play with gasoline
You are both right and wrong. I'll try to clarify. The heat transfer between a fluid and a solid wall happens a the viscous zone so called boundary layer, where friction happens. On the other hand, the temperature which modulates this heat transfer is the external flow total temperature which is where viscous effects are negligible.
:P
The total temperature is given by the compressible isentropic flow behaviour:
Tt/Tamb = 1+ (k-1)/k*M^2, where
Tt is the total temperature in K or Rankine,
Tamb is the ambient temperature in same units above,
k is the heat coefficient ratio, for the air is 1.4 and
M is the mach number.
Thus, for a 3.5 Mach number, the maximum for SR-71, the total temperature is:
Tt = Tamb*(1+0.29*3.5^2)=Tamb*4.5,
and for a Tamb of -50 degrees celsius (-58 deg Fahrenheit), becomes,
Tt = 223*4.5=1003K = 730 deg C = 1346 deg F
At that speed, the ambient is sooooo hot! even when the atmosferic temperature may be soo freezing!!!!.
At the leading edge of the SR-71 wings and the fuselage nose, you reach such temperature without any kind of viscous effects; just because you stagnate the flow isentropically there: you are more right than wrong at the end
Please don't try it!
Of course, at a very hot day *perhaps* you can do it because there is so much amount of gasoline evaporated that the fuel/oxygen ratio is bigger than the required for a combustion; but do not play ever with gasoline!!!.
But, when you address more than 1gb+something of memory at one executable, the access to that memory becomes much more expensive. Whereas, in 64bit you get full speed addressing!
My experience with numeric code, compiled in 32bit and 64bit is that the same code tends to be about a 15% slower in the 32bit case.
When the code uses more than 1Gb of RAM, the differences are much higher.
The tests where done in a 64bit install with a 32bit chroot (so the kernel was 64bit). The 32bit executable performed exactly under the 32bit chroot or directly on the normal 64bit usage. (the 32bit chroot was used to compile the binary, since it is quite easy to setup)
I'm not sure if at that time I did dual-boot to check the 32bit executable in a 32bit kernel, but I guess I would get the same results: poorer performance of about a 15% when memory usage is directly addressable with 32bit...
I'm a 64bit Ubuntu user for last two years and a half, and time ago it was trickier to use a 64bit OS, but nowadays is pretty the same to install a 32bit or a 64bit version. And with a 64bit version you can address more RAM, so IMHO it does not make sense to use a 32bit version unless your hardware is too old or you are in a certain production environment.
I don't really know Objective-C, but if you know C, you can get incrementally improving in your knowledge of C++.
C++ is massive, but one can use a subset that full fills her needs.
Whereas your comment is insightful and your comparison to the eldest Motif is appropriate, it is funny that even in such case there exist a way to make a Motif program run inside a windows box (besides the obvious vmware way).
no, it is not the reason. However, I didn't know about them and I appreciate your pointer. Thank you very much.