Domain: ntu.edu.tw
Stories and comments across the archive that link to ntu.edu.tw.
Comments · 21
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Two for one?
Can we measure two benefits?
1) Create Biofuel
2) Clean the environment
Example 1: Cattails remove toxins & pollution from wetlands, stormwater. http://www.scer.rpi.edu/bwe/?p=369
Example 2: Sunflowers decontaminate radioactive soil. http://www.ecaa.ntu.edu.tw/weifang/cea/sunflowers.htm
Example 3: Algae blooms http://www.npr.org/2013/08/11/211130501/the-algae-is-coming-but-its-impact-is-felt-far-from-water
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Re:What about plants
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Re:This was a "psychic" trick in the 70s.
Back then it was called "demo-optical perception."
Citation needed. Oh wait.
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Re:Porting to Cell DSPs
Is there an open source Java OpenGL implementation? That would be a great package to see running on the Cell.
I presume you're looking for a software implementation? If so, then you might try this:
http://www.cmlab.csie.ntu.edu.tw/~robin/JavaGL/
I've never used it, so I can't vouch for it, but it's supposedly a software implementation of the OpenGL API and renderer in Java. -
Re:Question on how PRAM works and is manufactured
Read the paper
http://www.st.com/stonline/products/literature/an/ 10122.pdf
and this one
http://newslab.csie.ntu.edu.tw/~johnson/public_fil es/R-FLO436_Chang.pdf
Because I wouldn't mind getting a flash drive. I'm just a bit skeptical.
Well it wouldn't surprise me if some flash disks get this disasterously wrong to be honest. Some of the lifetimes on page 6 of the Chang paper look a bit low for comfort - around 4 years for NFTL. -
Poincaré and Hilbert
Einstein's work was already in very simple laymen's terms. I don't know what the point is in trying to make it into braindead powerpoint.
Einstein's work on STR is "Poincaré for dummies", Einstein's work on GTR is "Hilbert for dummies".
STR
Einstein's paper "On the electrodymanics of moving bodies" contains nothing new. It was actually Poincaré who was the first to correctly state the special theory of relativity (the transformation formulas were found by Woldemar Voigt in 1887, H.A. Lorentz in 1892, Sir Joseph Larmor and others)
In 1898, Poincaré attacks the distinction Lorentz and Larmor make between "local time" and "universal time": "Nous n'avons pas l'intuition directe de l'égalité de deux intervalles de temps. Les personnes qui croient posséder cette intuition sont dupes d'une illusion... Le temps doit être défini de telle facon que les équations de la méquanique soient aussi simples que possible. En d'autres termes, il n'y a pas une manière de mesurer le temps qui soit plus vrai qu'une autre; celle qui est généralement adoptée est seulement plus commode. ...Il a commencé par admettre que la lumière a une vitesse constante, et en particulier que sa vitesse est la même dans toutes les directions. C'est là un postulat sans lequel aucune mesure de cette vitesse ne pourrait être tentée. Ce postulat ne pourra jamais être vérifié directment par l'expérience; il pourrait être contredit par elle, si les résultats des diverses mesures n'étaient pas concordants. Nous devons nous estimer hereux que cette contradiction n'ait pas lieu et que les petites discordances qui peuvent se produire puissent s'expliquer facilement. ...c'est que je veux retenir, c'est qu'il nous fournit une règle nouvelle pour la recherche de la simultanéité... Il est difficile de séparer le problème qualitatif de la simultanéité du problème quantitatif de la mesure du temps; soit qu'on se serve d'un chronomètre, soit qu'on ait à tenir compte d'une vitesse de transmission, comme celle de la lumière, car on ne saurait mesurer une pareille vitesse sans mesurer un temps. ...La simultanéité de deux événements, ou l'ordre de leur succession, l'égalité de deux durées, doivent être définies de telle sorte que l'énoncé des lois naturelles soit aussi simple que possible. En d'autres termes, toutes ces règles, toutes ces définitions ne sont que le fruit d'un opportunisme incoscient." (H. Poincaré, La mesure du temps, in Revue de métaphysique et de morale 6 (1898), pp. 1-13)
In 1902, Poincare writes there is no absolute time and no absolute space: "1. There is no absolute space, and we only conceive of relative motion; and yet in most cases mechanical facts are enunciated as if there is an absolute space to which they can be referred. 2. There is no absolute time. When we say that two periods are equal, the statement has no meaning, and can only acquire a meaning by a convention. 3. Not only have we no direct intuition of the equality of two periods, but we have not even direct intuition of the simultaneity of two events occurring in two different places. I have explained this in an article entitled 'Mesure du Temps.' 4. Finally, is not our Euclidean geometry in itself only a kind of convention of language ? Mechanical facts might be enunciated with reference to a non-Euclidean space which would be less convenient but quite as legitimate as our ordinary space; the enunciation would become more complicated, but it still would be possible. Thus, absolute space, absolute time, and even geometry are not conditions which are imposed on mechanics. All these things no more existed before mechanics than the French language can be logically said -
Einstein & Poincaré
Einstein's paper "On the electrodymanics of moving bodies" contains nothing new. It was actually Poincaré who was the first to correctly state the special theory of relativity (the transformation formulas were found by Woldemar Voigt in 1887, H.A. Lorentz in 1892, Sir Joseph Larmor and others)
In 1898, Poincaré attacks the distinction Lorentz and Larmor make between "local time" and "universal time": "Nous n'avons pas l'intuition directe de l'égalité de deux intervalles de temps. Les personnes qui croient posséder cette intuition sont dupes d'une illusion... Le temps doit être défini de telle facon que les équations de la méquanique soient aussi simples que possible. En d'autres termes, il n'y a pas une manière de mesurer le temps qui soit plus vrai qu'une autre; celle qui est généralement adoptée est seulement plus commode. ...Il a commencé par admettre que la lumière a une vitesse constante, et en particulier que sa vitesse est la même dans toutes les directions. C'est là un postulat sans lequel aucune mesure de cette vitesse ne pourrait être tentée. Ce postulat ne pourra jamais être vérifié directment par l'expérience; il pourrait être contredit par elle, si les résultats des diverses mesures n'étaient pas concordants. Nous devons nous estimer hereux que cette contradiction n'ait pas lieu et que les petites discordances qui peuvent se produire puissent s'expliquer facilement. ...c'est que je veux retenir, c'est qu'il nous fournit une règle nouvelle pour la recherche de la simultanéité... Il est difficile de séparer le problème qualitatif de la simultanéité du problème quantitatif de la mesure du temps; soit qu'on se serve d'un chronomètre, soit qu'on ait à tenir compte d'une vitesse de transmission, comme celle de la lumière, car on ne saurait mesurer une pareille vitesse sans mesurer un temps. ...La simultanéité de deux événements, ou l'ordre de leur succession, l'égalité de deux durées, doivent être définies de telle sorte que l'énoncé des lois naturelles soit aussi simple que possible. En d'autres termes, toutes ces règles, toutes ces définitions ne sont que le fruit d'un opportunisme incoscient." (H. Poincaré, La mesure du temps, in Revue de métaphysique et de morale 6 (1898), pp. 1-13)
In 1902, Poincare writes there is no absolute time and no absolute space: "1 Il n'y a pas d'espace absolu et nous ne concevons que des mouvements relatifs... 2 Il n'y a pas de temps absolu; dire que deux durées sont égales, c'est une assertion qui n'a par elle-même aucun sense et qui n'en peut acquérir un que par convention... 3 Non seulement nous n'avons pas l'intuition directe de l'égalité de deux durées, mais nous n'avons même pas celle de la simultanéité de deux événements qui se produisent sur des théâtres différents; c'est ce que j'ai expliqué dans un article intitulé la Mesure du temps; 4 Enfin notre géometrie euclidienne n'est elle-même qu'un sorte de convention de langage; nous porrions énoncer les faits mécaniques en les rapportant à un espace non euclidien qui serait un repère moins commode, mais tout aussi légitime que notre espace ordinaire; l'énoncé deviendrait ainsi beaucoup plus compliqué; mais il resterait possible. Ainsi l'espace absolu, le temps absolu, la géométrie même ne sont pas des conditions qui s'imposent à la mécanique; toutes ces choses ne preéexistent pas plus à la mécanique que la langue francaise ne préexiste logiquement aux vérités que l'on exprime en francais."(H. Poincaré, La science et l'hypothèse, 1902 -
Re:Damn...
> Microsoft Air-traffic Control Software? Shudder...
It looks like you're trying to direct a pilot to land a plane. Would you like to:
- Have the pilot land at Cirque du Soleil and tell him it's Denver International Airport?
- Redirect the plane to Chicago, but send the luggage on to Orlando?
- Adjust the ground level to send the plane and all aboard to fiery doom like that scene in Die Hard 2? -
Re:Ebola-Cold.
That actually depends which strain you're talking about.
The Reston strain is airborne, but is not fatal to humans. The problem, however, is that Reston is very similar to the Sudan and Zaire strains, so airborne mutations are not out of the question for the other strains. Additionally, at late stages when R & Z are extremely infectious, coughing will spew droplets of blood, which if care is not taken will infect others who breath them in.
Some information taken from here
See also: Wikipedia -
Re:4:1:1 vs. 4:2:0
The notation for subsamping was never defined as what you say. That is the main problem here, there is no normative standard definition for "4:4:4", "4:2:2", "4:2:0", and "4:1:1". As a result, there is a lot of misunderstanding and misinformation about subsampling...
A definition with odd/even lines doesn't make sense: First, any decent subsampler does not decimate, but uses a filter, therefore there is no different amount of chroma samples for odd and even lines. Second, in most standards the centerpoint for the chroma samples is not right on top of the luma samples, but is in between the luma samples halfway in between the lines (sometimes columns too), as can be seen for example on this slide about subsampling for MPEG).
Let's look at "4:2:0" and "4:1:1" in the history of digital video.
The MPEG people used "4:2:0" in the text of their standard (ISO/IEC 11172 & 13818) to mean chroma subsampling of a factor of two in both directions (horz/vert). However, the JPEG people used "4:1:1" in the text of their standard (ISO/IEC 10918) to mean the exact same thing (as can be seen on slide 8/13 and 9/13 of this presentation (pdf))
Both JPEG and MPEG predate DV video.
Now, for the convoluted world of the DV format. DV is not a standard of an international standards body. It is a JPEG-like format agreed upon by a bunch of consumer electronics companies for use in their digital camcorder products, which later convoluted with proprietary modifications (DVCAM/DVPRO)... that just happens to sort of work, usually... another clicky.
So, in the 'DV world', a lot of people use "4:1:1" to mean no vertical subsampling and a factor of four horizontal subsampling (for NTSC DVCAM). But that doesn't mean that that is the factual meaning of 4:1:1.
It's the same as when the mainstream press says hacker when they mean cracker. People take a convenient sounding/looking term and give their own new meaning to it. -
Re:the stupidity doesn't stop here....
:) I think it works... there are many companies which have products for this purpose. Do a google search for "digital audio watermark" to find examples (including technical papers on citeseer). What is termed "robust" watermarks (as opposed to "fragile") can survive the usual audio processes (D/A, A/D, dsp, lossy compression, etc.).
e.g.:
a press release
verance
Overview of Felten's Attack on SDMI
Template Matching -
Re:DivX SVCD?Why? Why need support to play DivX format in a DVD player?
Umm, that's easy. Why would I bother converting all my DivX movies to svcd (not a quick process) when I can just burn and play them, or even play them over the network?
DivX may have better audio than SVCD...but nothing will ever provide the DD 5.1, DTS, and 6.1(7.1???) sound quality of real DVDs.Wow, thanks for that insight. The AC3 Audio codecs are made by Dolby, and it sounds quite good in my opinion. Not to mention they are used in many of the movie rips that can be downloaded from the net.
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Just to clear a few things upThere seems to be a bit of confusion surrounding this release, so this is what I've been able to gather:
The original DivX
;-) codec (as used in all the avi movies downloaded from wherever) is simply a hacked version of Microsoft's own MPG4/MPG3 codecs, and actually adds nothing to them whatsoever apart from allowing their use in .avi files. I believe this was simply a binary hack, the original source code was not used or accessed in any way.This new, OpenDivX codec (home page) is an open source-ish implementation of parts of the MPEG4 standard. It was not written completely from scratch though, it is based on another mpeg4 implementation known as MoMuSys.
I would assume that the OpenDivX code has little in common with the original DivX
;-) code, which is Microsoft's implementation after all. That would explain the differences in en/decoding speed and quality. From the tests I've carried out, however, it could have a bright future (bizarre license aside).That's assuming, of course, that WMV8 doesn't crush all competition.
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Re:SOS
Do you have a HPT366 ide controller. It's part of the chipset on Abit BE6 etc.
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Non windows apps to do this?I wish there was a Lame / Ogg like effort to produce MPEG4 like video outside of just the windows world. Can't we have TMPGEnc and DVD2AVI in Linux world too? Can't we have an mpeg4 codec and good VCD / SVCD support? So far i have only seen decent attempts from Heroine Virtual but almost nobody else. Is digital video taboo in non windows machines?
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Re:Is OpenBSD still relevant?At this point its pretty moot. FreeBSD (the BSD that I use on most of my UNIX systems at home ) is getting very very similar to OpenBSD it terms of "code review". And anytime I have had problems (even if they are 'in the faq') I have gotten polite reasons from the FreeBSD and even the NetBSD camps.
Some people find Theo's development style and anti-social behavior to be abrasive, but since when have those qualities stopped anyone from being a fantastic software developer? Consider Picasso for a moment; although you may find him intensely disagreeable as a person, does that mean you will never find meaning in his paintings?
His abusive/abrasive behavior is one reason why people WON'T deal with OpenBSD/OpenSSH.. why should I have to deal with a spokesperson like that ? If thats how he acted privatly, "offline" then fine.. But thats NOT how the spokesperson for a project should be when in the public eye (on usenet, etc.)
No.. it doesn't adversely affect his being a programmer. But it DOES affect how people interpret his project (Theo = Abusive, Abrasive, if I need help, I will get abuse... Therefore I don't want to deal with the project).
I urge you to reconsider OpenBSD, if you are holding back simply because of Theo's personality. OpenBSD is a truly refined, unusual experience, and, trust me on this; you can enjoy the meal without liking the chef
I "could" enjoy OpenBSD but not with their current "chef" in charge. In this world with plenty of options, I just go to a chef (like Jordon Hubbard from FreeBSD) who is polite and curtious to the customers, not rude and demeaning.
And besides, OpenBSD has had reviews done but if you look, they still have had many of the same problems that other BSD's (and Linux have had) do exist in OpenBSD.
And behavior like this doesn't give me warm fuzzies about dealing with him:http://freebsd.ntu.edu.tw/bsd/10/2/17/ 1.html (yes its a few years old, but from what I have seen he hasn't grown up yet)..
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Re:Bah
Well, make your own decisions. The information is easy enough to find, and Theo's e-mail is damning enough.
However, this is what I was talking about before -- I finally found the reference. It's sad how information can die out, on the net.
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pb Reply or e-mail; don't vaguely moderate. -
Re:Maybe its not so bad...
Even though you guys tried to convince me it wouldn't work <g>, I tried to install RH 6.1 on my UDMA/66 drive, and everything was a breeze, following the instructions (now I have the link! here).
Only thing I'm yet to install is LILO. Meanwhile, the boot floppy is working great.
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Marcelo Vanzin -
Re:Anybody have a changelog?Also, does Red Hat support the Highpoint HPT366 ATA/66 chip?
The HPT366 patch is in the 2.3.x kernels and will thus not be available until 2.4 is released. However, there are at least two ways for you to get access to your extra HDs without being forced to run a development kernel:
- Without rebuilding the kernel: Use the backward compatibility of the IDE controller and boot up LILO with a command similar to ide2=0xd800,0xd807. That'll force the kernel to detect whatever disk you have on the first HPT366 controller and you won't have to recompile the kernel. But you'll loose UDMA/66 and will have to do with the normal 33Mb/s transfer rate.
- Get the HPT366 patch from here, patch and rebuild kernel 2.2.14 and you're set to go.
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Re:Anybody have a changelog?Also, does Red Hat support the Highpoint HPT366 ATA/66 chip?
The HPT366 patch is in the 2.3.x kernels and will thus not be available until 2.4 is released. However, there are at least two ways for you to get access to your extra HDs without being forced to run a development kernel:
- Without rebuilding the kernel: Use the backward compatibility of the IDE controller and boot up LILO with a command similar to ide2=0xd800,0xd807. That'll force the kernel to detect whatever disk you have on the first HPT366 controller and you won't have to recompile the kernel. But you'll loose UDMA/66 and will have to do with the normal 33Mb/s transfer rate.
- Get the HPT366 patch from here, patch and rebuild kernel 2.2.14 and you're set to go.
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OS/2 version is also available
You can get the OS/2 version of Enlightenment from http://r350.ee.nt u.edu.tw/~hcchu/os2/ports/xfree86/#enlightenment
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Timur Tabi
Remove "nospam_" from email address