Slashdot Mirror

(the subject is flamebait and overstated, but it did get you to read this, didn't it?)

According to Peter Norvig and Greg Sullivan, most of the patterns in the Gang of Four book are there to show users of common OO languages the canonical ways of getting around design flaws in those languages.

Norvig says 16 of 24 patterns either vanish completely or are significantly easier to implement in a dynamic OO language like CLOS or Dylan; Sullivan implements a tiny OO language in Scheme and uses it to implement all 24 patterns, with similar results.

Go read the papers before modding me down, huh?

Why was this story linked to Science Blog and not the actual MIT press release? Science Blog adds absolutely no content whatsoever to this story, they simply cut and pasted the first two paragraphs as a summary and then included the rest of the press release. If you want to mention that you saw this at Science Blog that would be one thing but saying that "there's a story on SB about X" is really pushing it.

Next up on the gripe list, slashdot story submissions that consist of a cut and paste of the first few sentences of the linked content. If you can't write a concise summary of the article in your own words, then you probably didn't read it, you're lazy, or you lack the language skills of a ninth-grader.

The term "propaganda," incidentally, did not have negative connotations in those days. It was during the second World War that the term became taboo because it was connected with Germany, and all those bad things. But in this period, the term propaganda just meant information or something like that. So he wrote a book called Propaganda around 1925, and it starts off by saying he is applying the lessons of the first World War.

This is one of the best articles that I have ever read about the trust relationship of and the double edged sword that is the current state of email. Dertouzos (God bless his soul) did a great job of sounding the alarm and offering practical advice. Well worth the read.

This is because they use AOLserver which is a massively scaleable and powerful web application server. Some of its features are:

• Multi-threaded - It's been multi-threaded since its original development in 94 or 95.
  
• Native DB API and DB connection pooling
  
• Embedded scripting language, which is Tcl, which allows for extremely fast development. It also allows for .ADP pages, like .ASP, .JSP or .PSP pages.
  

The reason Tcl is the embedded language is that AOLserver was developed in the early nineties, when Tcl was the hot new language. If the system were to be developed today, I'm sure that the developers would have chosen Python, Perl or some other more buzzword compliant language that has a strong following.

That being said, Tcl in AOLserver still rocks for developing DB backed websites. In fact, the Open Architecture Community System (OpenACS) is a complete web toolkit for building just these kinds of sites. The Sloan School of Management at MIT recently funded the development of an open source course management system called dotLRN that is build using the OpenACS as its foundation.

So Tcl isn't just a GUI tool or a glue language. It's also a great language for web scripting!

talli

Well, if someone was serious about it. The Crystal/Cirrus CS8900A has an 8-bit interface mode. There are a number of projects on the web interfacing it to several 8-bit processors. Someone could conceivably make a cartridge containing an ethernet interface and the Contiki Desktop in ROM (I'm not holding my breath though).

The French extended considerable financial support to the Congressional forces. France also supplied vital military arms and supplies, and loaned money to pay for their purchase.

French military aid was also a decisive factor in the American victory. French land and sea forces fought on the side of the American colonists against the British.

One of the components of an Oxygen network is the anyonymous handheld device, which is essentially a generic device that can turn into any device one wants. When one picks up a handheld, it recognizes one's face and turns into 'their' handheld by downloading their contacts, their schedule and so on. The handhelds also use voice recognition technology to do various useful things, e.g. "Call home..." Upon getting this voice command, the handheld morphs into a cellphone and begins to dial the line to the entitiy called "Home" in your address book. Clearly - lots of interesting issues here, including all the nifty recognition technology as well as general enough hardware to support devices simulating each other. All this and more info and videos at Project Oxygen

I agree that no one is forcing the whiners to use all the extra functionality in a cellphone. We are moving more towards an age where people carry one device to do everything and not a cellphone, PDA and a pager.

Now I'm tired of this....

Please Read This to see what YOU Americans owe France for their help in YOUR war of independence

That's right, if it wasn't for the glorious French, you'd still all be UK subjects over the pond.

Why patents suck: http://lpf.ai.mit.edu/Images/chess-flyer-crop-thum bnail.jpg

You can get sued for writing a program like the one above. It's 3 lines of code. No, really guys. It's 3 friggin' lines of code.

Look at it! It's a patent on the fucking EXCLUSIVE OR operation that's standard in every microchip ever made since the 1950s.

THAT, my friends, is why I don't trust patents. You never know how they can be extended.

PLUS they're a large gov't organization that's slow and stagnant. Let the people innovate!

....that programmers are not web designers :-)

-$|{

Think Kerberos cross realm authentication. If school x enters into a agreement with school y that students from each school will be able to use network resources on the other campus, the easiest way to manage that is to set the KDC to allow cross realm authen (using a shared secret) and then set up ACLs to allow any UID from the other school access to those resources that are to be shared.

Apparently this guy isn't the only one interested in pancake flipping. Take a look at this paper entitled "Bounds for sorting by prefix reversal" (AKA Pancake flipping problem) co-published by one William H. Gates...

Certain language features lend themselves to abuse (C++ operator overloading has been held up as example of this in the past). In my view, a well designed language should provide powerful features that also lend themselves well to "modular-reasoning". By this I mean that in an arbitrarily large software project, I can look at one tiny bit of it and work out something of what it's doing.

Given that most large software projects are, in their totality beyond one person's conception, I'd say this was a highly desirable feature in a modern computer language. Features like AOP undermine this kind of modular reasoning by changing the semantics of code that was originally written (and tested) without the knowledge that it would be changed like that.

There are all kinds of invariants that programmers maintain when writing their code, and this kind of feature seems like a very good way of breaking them in all kinds of subtle ways. Welcome to Bug City.

Random comment: If you're interested, this is an OO language which seems to be genuinely well done.

For example, with one of these, you could implement a truly distributed DNS system that doesn't use hierarchy or centralization, and thus would be much more immune to DoS attacks than the current system.

Here's a little hint, buddy. Anything in the US governement with a launch date further than 2 years from now is entirely speculative.

Thanks for the hint. Here's one for you. Weapons systems usually take at least a decade to go from from first funding to first deployment. Some programs do get canceled along the way, but not that many. A prmoise of tax cuts ten years from now is not worth the paper that it is printed on. A promise to deploy a weapons system is an entirely different thing - just consider how much trouble Rumsfeld has had trying to cancel one new artilery system.

A methodology hasn't made really made it until somebody has published a Proper Book.

What, like The Art of the Meta-Object Protocol by the very same Gregor Kiczales et al, pub. MIT Press, 1991?

Like most things, AOP is only new if you don't know LISP. :-)

This MIT article has a photo of McLurkin and the robots

Looking at the tuition rates (pdf) it would actually cover 2 terms :(

Well, once I become a billionaire...

Are there any decent introductions to BGP and how it operates at the Core?

let me help you control your anger.

The point is not who and how, but merely that obscurity is a useless principle in security. I could mention certain modern software companies here, but since names makes you tick....

We are disagreeing on terminology. Here is a reference to what I mean by serialization:

Serialization creates distinguished sets of procedures such that one execution of a procedure in each serialized set is permitted to happen at a time.

i went to the the mit website when they showcase the robots, link

i downloaded a few of the videos and was not that impressed. i am sure there is a lot of time and effort put into this, but i worked a summer camp where we taught kids a half of the things they were show casing... this company sells little robots and we can even buy little ifrared recievers imiters, light sensors, etc. we program it with BASIC to follow the light/dark, take commands from a remote control, pick things up. all this for just a 200bucks.

now, many of the "crown control" things were odviously a bit more complicated. but is it THAT special? sending signals that push away or get closer to other bots.. not that new.

one thing that i must say is that programming for these premanunfactured bots is easy, but if you ever try to linux-fy, and tweak, or play with the goodies inside, goodluck. Me and friend tried to make a linux compiler for it, and got no support from the company, no techdoc, nothing. (we were not surprised)

Robotic ants inventor James McLurkin wins $30K Lemelson student prize

not an avi, but it is a pic of the inventor with some of his toys

Human rights groups in countries with authoritarian governments are often persecuted, their computers confiscated to get the names of their informants. Generally encryption (PGP/GPG) is sufficient in these cases to protect their data - unless the government is evil enough to torture them to reveal their private key/passphrase. In cases such as this, steganography allows plausible deniability.

For more information on the uses of encryption in human rights organizations, read these letters to Philip Zimmermann (the creator of PGP).

Human rights groups in countries with authoritarian governments are often persecuted, their computers confiscated to get the names of their informants. Generally encryption (PGP/GPG) is sufficient in these cases to protect their data - unless the government is evil enough to torture them to reveal their private key/passphrase. In cases such as this, steganography allows plausible deniability.

For more information on the uses of encryption in human rights organizations, read these letters to Philip Zimmermann (the creator of PGP).

Having watched him operate for several years, it seems that Rob Poor thinks that simply by 1) talking about mesh networks for several years, 2) building a half-assed mesh simulator for his M.S. thesis that didn't even work, 3) blustering his way through a Ph.D. on the strength of that old simulator, 4) raising VC for an ill-posed attack on a very difficult problem, and 5) sitting on topic committees that have many fine lunches and dinners at consortium expense, he will somehow gain insight into a problem that he still doesn't even understand.

But if you really want to believe the hype, then perhaps you'll be impressed by the advanced level of technical sophistication evidenced by this presentation on his website. Don't forget your free sample of PIC code that shows us all how gosh-dang simple it is to be a radio engineer! Want to build a mesh? Just sprinkle a few thousand PICs in the environment and they'll self-organize into a network through the emergent properties of entrainment!

It seems so obvious; why didn't we think of that?

Is there any possibility of putting all this...errr...rocket science into a free web site? Something like MIT's OpenCourseWare

I find it interesting that because it's google, some /.-ers are saying essentially "good for them!" But at the heart of it, it makes no difference who it is or what their intention is.

Kids, software patents are bad, mm-kay...

Voyager, not Pioneer, took a "Golden Record" with encoded images, spoken greetings in dozens of languages, a variety of natural and human sounds, and an anthology of music from around the world, including both classical (e.g. Bach) and popular (e.g. Chuck Berry) selections.

The record is 12 inches in diameter and plays at 16 2/3 r.p.m. The long-playing record of the day played at 33 1/3 r.p.m., but Carl Sagan's committee had the foresight to predict that advanced extraterrestrials would get double the music by playing their LPs at half the speed.

Just kidding. Sagan's committee included instructions for playing the record, and even a phonograph needle cartridge. I hope the species that finds it has ears.

Rodney Brooks proposed something similar for space exploration in 1989. Did anyone else see the Errol Morris documentary that features him? His paper is here: Fast, Cheap and Out of Control: A Robot Invasion of the Solar System

There was a programming class at MIT that used the swarm concept on AI for a game. The game was an RTS where each unit had it's own AI and could communicate to other units but not easily (short range, takes time). Each unit generally had a simple program, but your team had a fairly complex overall strategy. My team (Master Control Program) did pretty well in last years contest.

There was a programming class at MIT that used the swarm concept on AI for a game. The game was an RTS where each unit had it's own AI and could communicate to other units but not easily (short range, takes time). Each unit generally had a simple program, but your team had a fairly complex overall strategy. My team (Master Control Program) did pretty well in last years contest.

This does not look much different from genetic algorithms, that have been used for years to solve optimization problems: Intro to GA
Note the words: "computationally expensive".

A.

It looks like this is exactly the question that the person doing the work is trying to ask. The Community Connections Project outlines the nature of the research that they are doing. It's part of the Center for Refecltive Community Practice which seems to be doing a number of interesting projects combining community and technology. Oh and USA Today also ran a story on this and other community networks last November.

It looks like this is exactly the question that the person doing the work is trying to ask. The Community Connections Project outlines the nature of the research that they are doing. It's part of the Center for Refecltive Community Practice which seems to be doing a number of interesting projects combining community and technology. Oh and USA Today also ran a story on this and other community networks last November.

There are some apparent curiosities with current interconnection arrangements. If I am connected to a smaller ISP and I send an email to my friend at one of the four larger ISPs, the larger ISP will generally charge my smaller ISP for sending the email. However, when my friend at the larger ISP sends me a return email, my smaller ISP will have to pay the larger ISP once again.

BGP already provides some of these benefits for smaller ISPs by allowing peering relationships. Let's say there is a parent ISP A, with smaller ISPs B and C in a transit relationship to A (in other words, they pay A). If B wants to send to C, it normally has to go through A, and both B and C end up paying for it. If there is significant traffic between B and C, they may decide to set up a peering relationship, sending packets directly between one another and bypassing A. Many peering relationships are set up such that B and C don't pay each other anything, since they both end up saving money by bypassing A.

Also, if you think about it, if A charges B for anything going from B to A and B charges A for anything going from A to B, you end up cancelling much of the money they make from one another. Granted, the larger ISP will most likely come out ahead, but it still needs to pay its bills. So it raise prices anyway in order to recoup the money that was cancelled out. In effect, the amount that the larger ISP charges will be unchanged, but there is extra work involved in keeping track of all this information. To make an analogy, does it make sense for you to charge your ISP for packets that go one way and not the other? No, you're paying them for the connection that they provide.

Finally, how do we determine in what situations do charges apply? If an e-mail goes from A to B, it seems logical that A should pay. But if B makes a request for a web page and the web page is transferred from A to B, should A still pay? If we make different payment rules for different protocols, this will become a mess.

In summary, I don't see how this regulation will effect anything except to make everyones lives harder.

For some information on gene regulation (on/off, etc) see e.g. Lecture 16 here

(I know too little about biology and evolution to have any really hard opinions, so take this with a grain of salt. If you haven't heard about gene regulation, study more.)

It seems to me that if you believe in a purely physical cause for our existence (and evolution is in that direction), you should also hold the position that your experience of a consciousness is the result (by-product) of a physical process that is completely out of your control.

This apparent problem is based on a false view of who/what "you" are...that somehow a "self" apart from the rest of the universe exists...that somehow there's a "you" that's being mercilessly manipulated by a cold cruel universe. The way out of this apparent dilemma is to realize that you are not separate from the rest of the universe, that the self we usually think of is an illusion. The brain is a story-telling machine, and from sensory information it constructs plots and characters - including our "selves". Which is all fine an entertaining, so long as you realize it for what it is. Attaching to this fiction that mind creates is the cause of tremendous suffering.

I don't have time or space to explore this fully (duh!), but let me recommend Alan Watts' The Book (On the taboo against knowing who you are) , and Raymond Smullyan's The Tao is Silent, especially the chapter "Is God a Taoist?":

Mortal: Well, are my acts determined by the laws of nature or aren't they?

God: The word determined here is subtly but powerfully misleading and has contributed so much to the confusions of the free will versus determinism controversies. Your acts are certainly in accordance with the laws of nature, but to say they are determined by the laws of nature creates a totally misleading psychological image which is that your will could somehow be in conflict with the laws of nature and that the latter is somehow more powerful than you, and could "determine" your acts whether you liked it or not. But it is simply impossible for your will to ever conflict with natural law. You and natural law are really one and the same.

Mortal: What do you mean that I cannot conflict with nature? Suppose I were to become very stubborn, and I determined not to obey the laws of nature. What could stop me? If I became sufficiently stubborn even you could not stop me!

God: You are absolutely right! I certainly could not stop you. Nothing could stop you. But there is no need to stop you, because you could not even start! As Goethe very beautifully expressed it, "In trying to oppose Nature, we are, in the very process of doing so, acting according to the laws of nature!" Don't you see that the so-called "laws of nature" are nothing more than a description of how in fact you and other beings do act? They are merely a description of how you act, not a prescription of of how you should act, not a power or force which compels or determines your acts. To be valid a law of nature must take into account how in fact you do act, or, if you like, how you choose to act.

Mortal: So you really claim that I am incapable of determining to act against natural law?

God: It is interesting that you have twice now used the phrase "determined to act" instead of "chosen to act." This identification is quite common. Often one uses the statement "I am determined to do this" synonymously with "I have chosen to do this." This very psychological identification should reveal that determinism and choice are much closer than they might appear. Of course, you might well say that the doctrine of free will says that it is you who are doing the determining, whereas the doctrine of determinism appears to say that your acts are determined by something apparently outside you. But the confusion is largely caused by your bifurcation of reality into the "you" and the "not you." Really now, just where do you leave off and the rest of the universe begin? Or where does the rest of the universe leave off and you begin? Once you can see the so-called "you" and the so-called "nature" as a continuous whole, then you can never again be bothered by such questions as whether it is you who are controlling nature or nature who is controlling you. Thus the muddle of free will versus determinism will vanish. If I may use a crude analogy, imagine two bodies moving toward each other by virtue of gravitational attraction. Each body, if sentient, might wonder whether it is he or the other fellow who is exerting the "force." In a way it is both, in a way it is neither. It is best to say that it is the configuration of the two which is crucial.

For more interesting and enlightening writings by Olin Shivers, go here.

Rivest has published some more micropayment scheme before this one. One of them is called Payword . Payword allows certified customers to generate electronic coins themselves. Vendor can validate this coin by using the digital signature provided by the Bank. By doing this way, the real-time network communication between customersbank to buy/sell electronic coins is minimized which is always a bottleneck to many coin based scheme.

My final year project is an implementation of the payword scheme. Anyone interested can contact me and I can send you a copy of my report. jonearth@hotmail.com

As for other points raised here: The idea behind many small transactions being lumped together into a larger one makes this a feasable system to use when the cost per transaction (to credit the merchant) matters.

Consumers will be shielded from the statistics - the idea is their bank / the micropayment provider makes up the differences, absorbing the swings themselves (but having them dampered by the large sample size).

If you have mathmatical questions as to this scheme, read the paper - it's very complete (if a bit dense)

Bray is moron. Anyone who thinks they might learn something from reading one of his articles will be sorely disappointed. Better to go the the horse's mouth for a keener explanation.

The article is very misleading. Rivest has a paper on his website on a couple micro-payment schemes (I assume one of these is the basis for Peppercoin) that clears up the confusion.

Here are two schemes in the paper:
Scheme 1

1. The Customer buys something from the Merchant.
2. The Merchant is issued a P-Coin which is payable with probablity S (if payable, the coin is worth 1/S cents).
3. If the coin is payable, when the Merchant redeams it his account is credited with 1/S Cents and the Customer is charged 1/S cents (over time the customer's payments and purchases balance).

1. The Customer buys something from the Merchant.
2. The Merchant is issued a P-Coin which is payable with probablity S (if payable, the coin is worth 1/S cents).
3. If the coin is payable, when the Merchant redeams it his account is credited with 1/S Cents and the Customer is charged an amount equal to he amount he has spent since the last transaction that was processed (so over time payments and purchases balance).

The problem with Scheme 1 is the possibility of a customer overpaying. Scheme 2 solves this by shifting the risk (not really a risk, it all balances out over many transactions) of overpayment to the bank (in this case Peppercoin Co.). You are assured that you will never be charged more than you spend.

The key point is that only a small number of transactions are processed (from both the merchant's and customer's point of view) thus cutting costs.

Why the need for randomness? If Peppercoin just kept track of every transaction and paid the merchant in aggregate, it would still need to do a bunch of small transactions to charge the individual credit cards.

Why not just do the credit card transactions in aggregate (at the end of each month, say)? I'm not sure about this one. Maybe because the math is too uncomplicated if you do it that way.

Hey buttmunch -- the article (in German) does mention pork, aka "Schweinfleisch". As an American, probably for longer than you, I'd like to see you STFU until you learn a thing or two. Something tells me that'd be a long wait. Anyone who thinks this screening program will work needs to read this

Passenger profiling helps terrorists and organized crime.

Here is the original presentation on the topic: Peppercorn Micropayments via Better Lottery Tickets by Rivest which gives some more details.

Theres another "what's popular on blogs" webpage at Blogdex. It tracks links, showing which pages are most linked to.

Coming up with a chess program to beat Kasparov mercilessly just isn't fun anymore. I say we put more research into writing a chess program that will make him cry while beating him mercilessly