Slashdot Mirror

I mentioned that primates are very good at problem solving; please read better. However, primates are distinctly not good at passing down information; they perform much worse in tasks that require communication and cooperation than human children. They seem to have rather limited "theory of mind", and have difficulty discerning intents and thoughts of others.

Humans children are good at learning from others almost to a fault; if you have an instructor teach young children to accomplish a task, but insert a bunch of pointless steps in the middle that clearly contribute nothing to the task, the children will use and continue to use the pointless steps. A chimpanzee, by contrast, will generally proceed straight to the actual solution. It's picking up from the instructor that the task is possible, but ignoring what the instructor teaches as the procedure - great on contrived tasks with pointless tasks inserted, but not great in real world communication tasks involving complexity. We reached the state we are as a species by standing on the shoulders of those who came before us. If we had to solve everything on our own from looking at the world around us, if the only way we learned to do things was by looking at what others around us were accomplishing and reasoning out on our own how to do it, we would still be foraging in the wilderness like them.

No, this is not true. You need to bluff to play optimally. See for instance, http://cs.au.dk/~bromille/Pape...

Which is great news since Telegram encryption is utterly compromised:

http://cs.au.dk/~jakjak/master...

Good point.

Via http://humaniora.au.dk/en/events/tychobrahetomb/photosfromtheopeningofthetomb/

"These photos may be used by the press when credited. Photographer is Jacob C. Ravn, Aarhus University unless otherwise stated."

...is big in the demoscene.

Check out this 4KB realtime demo called 'Receptor'. (Download / Video)

You could use coloured petri-nets, a tool created by some phd student at daimi in aarhus (the Computer Science faculty of Aarhus University). Here is a link: http://wiki.daimi.au.dk/cpntools/cpntools.wiki I am not sure if it is useful, but surely a test worthy.

Heim's theory (not mine) also predicts very accurately masses and lifetimes of many elementary particles. The predicted masses were claimed to have been derived by Heim using only 4 parameters:
h (Planck's Constant), G (Gravitational constant), vacuum permittivity and permeability.

Calculations are so simple that you can perform them using Java interpreter of your web browser: Heim Calculator
There is no other theory which is capable of doing such thing.

Do you think it could be possible to achieve such accuracy by playing with only number of dimensions 6, 8 or 12?
Don't think it is possible.

/Joss

Java the language isn't so bad anymore ... Give Java a fresh look, it's come a long way.

The problem is that other languages came a long way too. Today, not having support for closures for a language is a shame (consider that VB has it already for more than a year now, and even C++ is adding it) - yet we are not going to see that in Java 7, that's still more than a year in the future, and God knows when Java 8 will be released, if it ever happens. Some other stuff in Java is rather messed up - generics are a prime example of that. It really is becoming a language that is too burdened by backwards compatibility.

It's also somewhat ironic that quite a few of the present C# team were prominent people in Java language design in the past. Mads Torgersen, currently C# program manager at MS, is the guy who originally designed generic wildcards for Java, and provided the reference implementation for them - both ending up in Java 5. Neal Gafter, a more recent Microsoft acquisition, and also now on the .NET languages team, worked on Java 1.4 and 5 compilers, but is probably most famous for his detailed proposal to add closures to Java - something that many people originally expected to see in Java 7, but that will most likely not happen anymore (Neal did his job - the reference implementation is available - but Sun apparently doesn't care enough to actually use it).

Java truly is becoming the COBOL of today: a stagnant, no longer actively developed language in which tons of existing code are written and needs to be maintained. This isn't meant to be disparaging, and there's certainly a place for such languages; but if you want reasonably modern language design, Java isn't going to offer that to you, while C# still can.

Use Heim Mass Calculator to easily compute masses of proton, neutron, electron and a lot of other particles as well, with a great precision (relative errors less then 0.00001) when comparing with most precise laboratory measurements available. The only hardware you need is Java in your browser.

This algorithm is based on 50-year old equations of Burkhard Heim thanks to his beautiful theory. Notice that it include computation of neutrino mass which was found in recent years. When Heim was working on his theory almost all scientist were sure that neutrino is massless. The only input which this algorithm needs is a bunch of well known constants: h (Planck's Constant), G (Gravitational constant), vacuum permittivity and vacuum permeability.

Our current "mainstream" (hate this word) theory known as Standard Model is full of inconsistencies which are forcing scientists to constantly mumble about "dark mass" and "dark energy" stuff.
It remembers me about Enrico Fermi's comment "Beautiful theory, wrong universe". Does it apply here?

/Z

You are talking about the SIMAP project which I am part of. SIMAP is short for Secure Information Management and Processing, see http://simap.dk/ (Danish only). An English article will soon be up on Eprint.

The Danish government that was not involved in the auction -- it was an auction where sugar beet farmers traded their production quotas for producing beets for Danisco, the only company producing sugar in Denmark.

The auction finished last month and was a great success for all involved parties. It was possible to run the auction because of modern protocols that require only a logarithmic number of rounds (by "round" I mean a network round-trip). The logarithm is in the bit-length of the input numbers, so for 32-bit inputs you will need ~5 rounds. The auction used the comparison by Tomas Toft, available in his PhD Progres Report: http://www.daimi.au.dk/~tomas/publications/progress.pdf

The SIMAP code is not (yet) online -- instead I can point you to a library for multi-party computation made by myself: http://viff.dk/. VIFF implements the same comparison protocol that was used in the SIMAP auction, as well as other primitives allowing you to do general MPC. VIFF is written in Python and is available under the GPL.

1. EHT (Extended Heim Theory) allows to easily calculate particle masses using only some physical constants. You can check this Heim Mass Calculator: http://www.daimi.au.dk/~spony/HeimMassFormula/HeimCalculator
2. Succesful prediction of masses of neutrinos.
3. Prediction of Heim-Lorentz force which most likely is being observed in ESA experiments performed by Dr. Martin Tajmar. During these experiments artificial gravity is being created.
   • ESA news about Tajmar experiments http://www.esa.int/SPECIALS/GSP/SEM0L6OVGJE_0.html and some other news.
   • M.Tajmar recent papper which references EHT (Droscher&Hausner): http://arxiv.org/pdf/0707.3806
   • Theoretical explanation of Tajmar Gravito-Magnetic experiments by Droscher&Hausner: http://www.hpcc-space.de/publications/documents/LauncherSymPaper2007-0-42JHCorrected22April.pdf
     This paper also contains proposal of modified experiment which will allow to verify if EHT is true and also allow to build very effective propulsion engine for spaceships. See this article: http://www.newscientistspace.com/article/mg18925331.200
4. Reasonable explanation why CMB Cold Spot appears to be cold without mumbling about Dark Matter/Dark Energy, thanks to Heim's corrected gravitional law.
5. EHT explains why it appears that there is not enough mass observable in the Universe without using Dark Matter concept.
6. EHT most likely explains weird effects measured during Gravity Probe B experiment, see: http://www.hpcc-space.de/publications/documents/FieldPropulsion.pdf.
   These effects are in agreement with Martin Tajmar findings, see: http://arxiv.org/pdf/0707.3806
7. Droscher&Hausner paper about space propulsion based on Heim theory http://www.hpcc-space.de/publications/documents/aiaa2004-3700-a4.pdf was awarded by AIAA in 2004.

Orly?

• Ele-Neutrino mass: 0.381 × 10^-8 MeV/c^2
• Mu-Neutrino mass: 0.00537 MeV/c^2
• Tau-Neutrino mass: 0.010752 MeV/c^2

Why, the ability to say, "Nope, we don't confine our employee's choice of languages." Well that and a morass of code based as much on individual whim as any logical need.

At least it means permanent work for the rest of us. I spent most of 2003 cleaning up a project where every tool had been used in the worst of all possible ways. CVS for local copies of source code at every workstation. Java for procedural programming and plain c for processing... plain text files. Of course.

I felt like one of those guys cleaning sewers, but I also got paid well, so I guess I am in debt to my predecessor who wrote the code.

In other words: keep up the good work and consider using a handful of esoteric languages! (Including Flip.)

Much of this is not correct.

Firstly, the Anglosphere has a long tradition of research into the study of signs and symbols. See, for example, Peirce (pronounced "purse").

Secondly, the term "semiotics" is wide-spread in English-speaking communities, while the term "semiology" (or varaints) tends to crop up in European discussion.

Thirdly, the fields mentioned may make use of semiotics, but semiotics is a discipline in its own right, with its own journals and authors. Just because a particular Slashdotter has only encountered these concepts in a cognitive science course does not mean that they enjoy no independent existence. (Calculus exists independently of engineering!)

Fourthly, semiotics is often broken down - very loosely - into three areas: syntactics (the form of signs), semantics (meaning of signs) and pragmatics (use of signs). Hence, semantics is one area of semiotic study.

To find out more about how the study of signs and symbols intersects with computers and information systems, try this bibliography. In particular, the work of Ron Stamper is quite influential.

I strongly recommend this highly-readable introduction to semiotics.

10 bits, 'twas 10 bits sir! Insecurity in GSM networks

Shamelessly stolen and slightly rewritten with added emphasis from jya.com (via Google Cache).

For non-technical reasons, which GSM MOU and its members refuse to disclose, the upper bounds of GSM voice privacy features was reduced by a factor of 1024. Curiously enough, this reduction of voice privacy solely benefits mobile call interceptors lacking a court authorized wire tap, since wiretaps conduced under court order can be performed at the base station or further upstream the telephony network.

Although it doesn't approach the problem from a spider "thought process" viewpoint NetSpinner is an interesting experiment in using evolutionary algorithms to build spider webs.

Perhaps the goofiest version of these is Flip in which you program by making a sort of pinball table. Similar in some ways to the Funges, but its own brand of weird.

Maxima (formerly macsyma) is a nifty tool I use. Command-line and GUI versions are available at the site, but the Emacs mode is much better looking.

If you can give someone a good bright flash before the one with which the picture is taken, that will contract their pupils and you won't see "red-eye".

Try that on me, and you will not be able to see what color the eyes have.

The appropriate Calvin and Hobbes reference

ai and dk should work.

I just create a list with all the short ones I could find that actually resolve.

This is why we use salted, iterated hashing.

I never really looked into exactly how crypt works, so I can't say for sure if it use iterated hashing. But in the case of MD5 passwords, it does indeed use a 48 bit salt (8 chars base 64 encoded). So mentioning /etc/shadow doesn't really make any sense. I still find it a bit worrying that they can crack a password with about 42 bits of entropy. A good 8 character password will have about 48 bits of entropy, which means it would take only 64 times as long to crack as what they can do now (a litle more if the hashing is in fact iterated). But the salt does mean they couldn't be cracking more than one password at a time. (I'm glad my root password is 16 chars long).

Yeah, I read about that as well - and reading between the lines of the media take, they were forced to drop the issue by the government. Apparently the Prime Minister who don't like "so called" experts telling people what to think, don't really like it, when people take issues with his own handpicked experts.

Since I have not read the (now withdrawn) findings by the Committee, I choose not to base my judgements on their findings.

By the way - I wasn't even thinking of that Committee, but was thinking of a smallish 5 page (I think) dissection (page 12 to 17 of that pdf) of a just a small part of his book - by Inge Henningsen, who is an associate professor at the Statistic Department of the Institute for Mathematical Sciences at Copenhagen University.

She also notes in her piece, that he's not actually a statistician like they know them at her department, as he has a M.A in Political Science from Århus Universitet and teaches "Methods" there as well. He is (as is noted) "an associate professor of statistics in the Department of Politital Science".

As to who has the better credentials when it comes to statistics - well, my oppinion is fairly obvious, but I've given you plenty of venues to explore yourself and leave you to draw your own conclusions.

Yeah, I read about that as well - and reading between the lines of the media take, they were forced to drop the issue by the government. Apparently the Prime Minister who don't like "so called" experts telling people what to think, don't really like it, when people take issues with his own handpicked experts.

Since I have not read the (now withdrawn) findings by the Committee, I choose not to base my judgements on their findings.

By the way - I wasn't even thinking of that Committee, but was thinking of a smallish 5 page (I think) dissection (page 12 to 17 of that pdf) of a just a small part of his book - by Inge Henningsen, who is an associate professor at the Statistic Department of the Institute for Mathematical Sciences at Copenhagen University.

She also notes in her piece, that he's not actually a statistician like they know them at her department, as he has a M.A in Political Science from Århus Universitet and teaches "Methods" there as well. He is (as is noted) "an associate professor of statistics in the Department of Politital Science".

As to who has the better credentials when it comes to statistics - well, my oppinion is fairly obvious, but I've given you plenty of venues to explore yourself and leave you to draw your own conclusions.

maybe not a firewall, but a honeypot so the app THINKS it is sending spam...

Anybody who wants to do that? Feel free to use my honeypot. (smtphoneypot.c) Put it on a Linux box acting as firewall, and use an iptables rule to redirect all outgoing SMTP connections to the honeypot. You might need to let a few test emails through to avoid them noticing. Hopefully it will work if you let their application contact their own mailserver, but no other mailserver.

Linux needs to do something *groundbreaking* that Windows doesn't
With Linux I can get a userinterface that is way more userfriendly than what Windows can offer me. Isn't that enough to make Linux a good alternative to Windows. I hear people saying Windows is more userfriendly than Linux. But I disagree.

why should I be a guinea pig?
Why should I be Microsoft's guinea pig? Or even Microsoft's <something worse>?

Actually I have written my own PC emulator, but it is far from as usable as DOSemu. I wanted to test a way to do the emulation with only 16 bytes used for ROM. As long as it was fun I kept coding. But eventually I ran into some problems. If I actually wanted to use all the available 255KB of UMB the kernel would Oops when the stack was on the same page as my ROM. I fixed the kernel bugs together with Manfred Spraul and Stas Sergeev. But I never got back to coding on my emulator.

diff -Nur linux.old/mm/mmap.c linux.new/mm/mmap.c
--- linux.old/mm/mmap.c 2003-12-03 23:20:57.000000000 +0100
+++ linux.new/mm/mmap.c 2003-12-03 23:23:22.000000000 +0100
@@ -1059,8 +1059,12 @@
if (!len)
return addr;

- if ((addr + len) > TASK_SIZE || (addr + len) < addr)
+ if ((addr + len) > TASK_SIZE || (addr + len) < addr) {
+ printk("do_brk: %d (%s): uid=%d euid=%d brk=%08lx\n",
+ current->pid,current->comm,
+ current->uid,current->euid,brk) ;
return -EINVAL;
+ }

/*
* mlock MCL_FUTURE?

But it is not likely to become widely available any time soon. The problem with quantum encryption, is that it is based on quantum states. These states are destroyed when observer (literally, you just have to look at them!), so it's not possible to read the data out and perform a "quantum dictionary attack", because how you read the data is part of the encryption

This is what makes quantum encryption perfect. If somebody has even read the signal, you will know it. If they haven't, the problem is solved.

However, in order to make use of this perfect encryption, the quantum state must not change. Therefore, any obstacle along the way (imperfections in the fiber optic cable, or any attempts to read the signal) will destroy the signal. This means that a quantum encrypted message cannot be transmitted through a switched network. Every switch (as we know them) would have to read the data, and pass them along. That is not possible.

Instead, a technique known as Quantum Teleportation could be used. It's developed mainly in Denmark, and uses something called Einstein-Podolsky-Rosen-beams to transport the quantum state. The catch is that they never read the state, because that would crush it. They simply transport it on a carrier wave, much like in Star Trek :)

did they implement the bluescreen feature?

Otherwise it is available for download here: bsod.c. The really great part about this version is, that you can have bluescreen exactly when you want, I for one use it when it is about time to go to bed.

What about that? Will we be finaly able to switch kernels without a reboot?

I did that back in the 2.2 days with monte. Later with 2.4 kernels I did a few changes, added a feature I was missing, fixed a bug and such stuff. In case you want to see it. But it was never completely stable and lacked SMP support.

kexec might be a better alternative. AFAIK it is being maintained and might even have made it into the 2.5 kernel.

I did a few small honeypots for the spammers to play with. SMTP and proxy.

I did a few small honeypots for the spammers to play with. SMTP and proxy.

I can't get to www.kernel.org/mirrors right now

I recognize that problem. I recall being unable to get to kernel.org for multiple days. At that time I decided to mirror the list of mirrors for my country.

The variance extension now has a homepage at http://www.daimi.au.dk/~plesner/variance.

Make that "even more so for governmental institutions". Some years ago I worked at a Danish business school where we had employment data for approx. 10% of the danish workforce (where you had been employed and for how long - it was based on social security data (primarily "ATP-indberetninger")). Data where anonymized both regarding workers and workplaces (and some other dimensions I don't remenber today) but even so available to only a very limited group of scientists.

Even so we weren't allowed to keep the data for very long. The authorities was afraid that we might be able to track information about individuals and therefore afterwards we weren't allowed to have access to anything but aggregated data.

Having access to data that were immidiately crossreferencable was a goldmine. Take for instance the publication "Danish economy May 1988, The Labour Market" from the Danish Economic Counsil: For the first time economist where able to get behind the truth of unemployment rates. They could see that 75% of the workforce (the "A-team") where fulltime employed and 25% of the workforce (the "B-team") walked in and out for employment. If the unemploymentrate was 10% it only ment that the B-team where unemployed for shorter or longer periods on average 40% of their time.

What is my point? Well, there are actually two: 1) Danish laws regarding privacy are being rigorously upheld by the relevant authorities and 2) universially crossreferencable data is a goldmine for researchers (here are a list of publications from the Danish National Center for Register based Research) and used wisely benificial for everyone.

The reviewer makes a great point (both philosophically and as a selling point for the book) - the ability to model state is absolutely invaluable when it comes to designing systems that are both effective and efficient.
My new hammer in the state modelling department is petri nets; I would recommend any developer looking to learn about state modelling investigate petri nets as a supplement and/or replacement for state charts.
The translation of state chart to petri net (and vice-versa) is fairly straight-forward; petri nets also provide more robust options for modelling concurrency (it is possible to model non-deterministic choices using petri nets). Colored petri nets add the ability to factor time into the model as well.
There are many petri net tools (of varying usefulness) available for a multitude of OSes; an impressive list can be found here.

perhaps you could "cross the streams" and safely mix them?

In fact I have recently been working on some code doing something similar to that. Unfortunately the time complexity is quadratic, and I'm afraid it cannot be done any faster. If you want to work with megabytes of random bytes, quadratic time complexity is going to be a pain.

Do you have the code for it posted anywhere.

Here are my SMTP and proxy honeypots. The programs are not yet complete, and the proxy honeypot in particular needs more features.

Do you have the code for it posted anywhere.

Here are my SMTP and proxy honeypots. The programs are not yet complete, and the proxy honeypot in particular needs more features.

When your CPU comes on and off of the HLT (halt) instruction, it creates a tiny electromagnetic field that is perceptible by your sound card.

Indeed I have had the very same problem with my computer. For a long time I simply added no-hlt to my kernel command line to remove the noise. To demonstrate that this was really the cause, I wrote a DOS program to provoke lots of noise on any computer suffering from this problem. The Turbo Pascal source is also available. (Don't try this program under Windows, It will not work).

Having lived with the no-hlt option for a long time, it came to my mind, that always wasting power in the CPU just because I occasionally want to use the soundcard without noise was stupid. Instead I wrote a patch that allowed me to switch the HLT instruction on and off as the soundcard driver was loaded and unloaded.

When your CPU comes on and off of the HLT (halt) instruction, it creates a tiny electromagnetic field that is perceptible by your sound card.

Indeed I have had the very same problem with my computer. For a long time I simply added no-hlt to my kernel command line to remove the noise. To demonstrate that this was really the cause, I wrote a DOS program to provoke lots of noise on any computer suffering from this problem. The Turbo Pascal source is also available. (Don't try this program under Windows, It will not work).

Having lived with the no-hlt option for a long time, it came to my mind, that always wasting power in the CPU just because I occasionally want to use the soundcard without noise was stupid. Instead I wrote a patch that allowed me to switch the HLT instruction on and off as the soundcard driver was loaded and unloaded.

When your CPU comes on and off of the HLT (halt) instruction, it creates a tiny electromagnetic field that is perceptible by your sound card.

Indeed I have had the very same problem with my computer. For a long time I simply added no-hlt to my kernel command line to remove the noise. To demonstrate that this was really the cause, I wrote a DOS program to provoke lots of noise on any computer suffering from this problem. The Turbo Pascal source is also available. (Don't try this program under Windows, It will not work).

Having lived with the no-hlt option for a long time, it came to my mind, that always wasting power in the CPU just because I occasionally want to use the soundcard without noise was stupid. Instead I wrote a patch that allowed me to switch the HLT instruction on and off as the soundcard driver was loaded and unloaded.

at long last i will be able to get my BSOD

Oh, you want a BSOD? I have implemented a BSOD for Linux.

Will Linus accept the BSOD patch for the kernel?

Of course not, Linus never accepts anything for the kernel if it can be done just as good in user mode.

The important thing, is to not provide Free (as in beer) training to one OS vendor, radically unbalancing the competition in the OS market.

The danish goverment spend millions of dollars each year on "teaching the people to use IT", which basically boils down to giving users a training course on all M$-OS and Office products.

I suggest having a mix of OS'es, so that the students have different experiences and learn from comparing those.

I myself is a student at DAIMI where machines with SunOS, HPUX (well not that many anymore) IRIX, GNU/Linux and Windows (Using vmware), and yes it's a pain with the differences between computers but:

1. You can just select to use the same OS every time
2. You learn a lot by seeing different solutions to the same problem

Hmm, I think you get it more than lightspawn does, but when you said "generics are old news" I was expecting that you were about to point out that templates (as they exist in C++, Modula-3 ('generics'), and numerous other languages) are basically a kludge to work around limitations in the object model.

The Beta programming language has a much better object model than Java/C++, which completely obviates the need for templates while still providing type-safety; basically, it lets you override 'data members' as well as 'function members' of your classes when subclassing.

Of course, Beta is a bit hard to come to grips with if you first encountered the idea of an object-oriented language in the context of C++ or Java. Still, a little mind-bending can be good for one's perspective...

open proxies

How much spam would we get rid of if there were no open proxies to abuse? I don't know, but it would be a lot I guess. Unfortunately that is more than we can possibly hope for, there are too many persons out there not capable of administrating a system properly.

But I do what I can to fight against the spam. I have installed an SMTP honeypot, and when they probe me for open relays, I will relay by hand. When they finally start trying to abuse my computer as open relay, it acts as a black hole. 50 000 000 spam mails have ended their life that way. Imagine how much spam we could get rid of if every slashdot reader would just receive and delete a few million spam mails.

In case anyone is interested, the source is here with slightly humorous responses. smtphoneypot.c

As a NASA contractor, I'm often reminded of the Dr. Demento Star Trek spoof Star Drek. With a mission to sell t-shirts, toy phasers, and anything else they can think of.