> Yes, but if it repeats that sequence every 6000 years, it really doesn't matter.
True, but...
> Modern pseudorandom alorithms are very good.
Not in this context. Pseudorandom algorithms approximate *mathematical* randomness.
> This completely ignores the issue at hand, which is that randomness is not > what people want anyway.
Exactly. People think they want "random", but they don't want mathematical random. They want things carefully and thoroughly mixed up in an approximately _even_ distribution with no proximate repeats and no naturally-ordered subsequences of any significant length, among other things.
> I think the lesson here is that you should never use a mathematically > random algorithm for [a]esthetic purposes.
You can use a standard rand() function as a starting point, but you have to fudge the results considerably. Also, using rand() is not the only way to achieve random. I have a program that generates twenty-question quizzes from a large bank of questions. For some things (e.g., selecting which questions to use) it uses rand() as a starting point and then fudges in various ways (e.g., tossing out questions whose answer references the same place in the source text as a question that has already been selected), but once it has selected which twenty questions it's going to use, it goes into decidedly-not-mathematically random mode to determine how to order them. Basically, it extracts the four special questions (two finish questions and two reference questions) and places one of them in each of four five-question quarter-quizzes, then it *sorts* the normal questions according to the order of their references and puts the first one in the first quarter, the second in the second quarter, and so on (wrapping around to the first quarter after the fourth). It does then randomorder each quarter and subsequently does a little more fudging (e.g., to make sure that the first and last questions of the quiz are not special questions)...
> For my "scramble_case" I weighted the probability against getting a > capitalized first letter, because that looks Too Normal.
Yes, that's exactly the sort of thing I'm talking about. If half or more of the words started with a capital letter, the scrambling wouldn't look "random" enough. It's a real paradigm shift from the meaning of random in computer science 101. It's the same reason my quiz generator must guarantee that the first question and the last question of the quiz are neither one ever a finish nor a reference question, even though with a mathematically random arrangement they (each) would be about a fifth of the time, over the long term. But if it happens even once, people complain that the quizzes aren't random and we should get a computer to do them. Most of the quizzers assume they're arranged by hand, but that would be a lot of work. However, even with all of the fudging I have built into the program, I still have to look over the quizzes before each rally and check that nothing went wrong and the quizzes are "random" enough. It just wouldn't do to have e.g. five "Why" questions in a row or some such oddity.
> However, we, in the US, have this little thing called the first amendment. The right to > free speech. What Spamhaus (or rather, the email server admin) does is interfere with > end users ability to receive free speech.
No. The stuff Spamhaus publishes does happen to be information that users or mail admins can use to decide which "speech" (in the form of email) they wish to listen to, but Spamhaus does not itself prevent anyone from receiving anything.
> This, in theory, should be up to the end user to OK.
No, it's up to the owner or administrator of the receiving mail server. They get to decide what information ("speech") may be published via their server, just as a newspaper publisher gets to decide which letters to the editor they want to publish, and if you write one and send it to them and they file it permanently, or for that matter shred and burn it, you have no valid complaint.
If the reader of the newspaper doesn't like this, he can buy a different paper, or, on the other side of the analogy, get email service from a different provider. (I do think ISPs should be up-front with their users about what services and techniques they use to limit spam, although frankly most end users are not deeply concerned with the technical details.)
If the writer of the letter, or the spammer, is unhappy with this arrangement, he can jolly well start his own newspaper (or mail service) and try to convince people to subscribe to it.
Personally, I'm not a large fan of blacklist-based approaches to limiting spam, but fundamentally it's up to the owner or administrator of the mail server, and Spamhaus is just offering advice.
The real problem in the legal case, according to one of the linked articles, appears to be one of jurisdiction or, more particularly, that Spamhaus apparently agreed to go to trial in the US and then backed out on it later. If that's true, it sounds like a pretty big mistake that will probably cost them.
Re:How vulnerable Windows XP really is?
on
The BBC's Honeypot PC
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· Score: 2, Informative
Yes, I think the reported who wrote up the article didn't fully understand the research that was being done. The point of the research is to look at what kinds of attacks are out there and, especially, which ones are common, as it helps security people to know better how to protect against them. The most important take-home message from this article, as near as I can tell, is don't connect a Windows XP system to the network without SP2. I knew that already (actually, I have a strong preference for an external firewall), but that doesn't make it less valid. If I were Microsoft my response would be to say, "See, this is why you need to turn on your Windows Firewall, like we recommend, and stay up-to-date with patches, like we recommend. This is why we put the Security Center in SP2."
The biggest problem here is that home users with OEM versions of XP that predate SP2 can run into trouble when they have to reinstall (not as frequent with XP as it was with Win9x but it does still happen from time to time). The most obvious solution is an external firewall.
I don't know what's available on the iPod hardware, but in a desktop scenario, I generally multiply the pseudorandom number from whatever standard rand function is available by the hundredth-of-a-second value off the system clock and then use modular arithmetic to get the result in the range I need. This is almost certainly not cryptographically sound, but it is good enough to seem unpredictable to most humans, so it's a good start for things like shuffling a playlist or pulling questions from a test bank.
You generally still want to fudge the results in various ways to make them appear more "random" to the user, though. It's easy to seem unpredictable, but you have to work a bit more to achieve "random". (Note here that I am using "random" here in the sense end users generally understand it, *not* in the math/programmer jargon sense. Even when I do various fudgings to make the results seem more "random", I still avoid using the _word_ "random", because that word sets the users' expectations pretty high, and I'm usually not that confident in my fudging algorithms.
> And in any event, the benefit of making the book searchable is dubious given > that the DRM could be used to limit your ability to search it, that searching > isn't really important for some books (e.g. most works of fiction)
Actually, I *frequently* find myself flipping back through earlier pages of a work of fiction, looking for an earlier reference to something, trying to remind myself of certain details. I would be very pleased to have all books be searchable.
I am not, however, entirely sure what this has to do with Windows Vista. Hopefully nothing, because although I'd like to have my books be searchable, I don't think I want to switch operating systems on my computer to get there.
Except for mathematicians and programmers, most think of "random" in a *very* different way from its technical definition. To most humans, saying that a particular sequence is "random" means *guaranteeing* certain things about it. Among them: the same element does not occur back-to-back, EVER, even if there are only a few elements total to choose from. Even more, if there are more than about half a dozen elements, the same element never occurs twice within about five positions. (So if you've got songs 1 through 7 on your iPod, and the first seven played are 5, 3, 7, 2, 4, 1, 6, then the next one has to be 5 or 3, or _maybe_ 7, or it doesn't seem "random" to most people. Yet, the order can't be the same every time through, either.) No element occurs substantially more often than any other element, even over the short term. If the elements have a natural order (e.g., alphabetical), then no three elements that are adjascent in that order can ever occur together in that order, nor should they occur together in the reverse order. (This gets particularly difficult to guarantee when the elements have more than one natural order, e.g., if the elements are people, you can't have three of them in a row by either name or age, or people notice and decide that the order is not random.) Even worse, if the elements can all be categorized into a small number of categories (e.g., by gender), you can't have "too many" from one category in a row. (How many is too many depends on the ratio, but if half of the elements are male and half female, having four of either in a row will make people cry foul, the order is not "random".) If certain elements stand out from the others in some significant way, they can neither occur first nor last. (For instance, if test questions are being drawn from a question bank, neither the easiest nor the hardest question should be first or last; if it is, people will say the order was not random.)
I could go on and on, but what it really amounts to is that when most people say "random" they mean "carefully arranged in a thoroughly mixed-up order". This is almost the *opposite* of what a mathematician or computer programmer thinks the word "random" means.
For this reason, when describing a mathematically-random sequence to an end user, I never EVER use the word "random". I generally call it something like "arbitrary" or "unpredictable". This greatly reduces complaints.
Now, as far as song frequency, I like to rate my tracks on a scale of 1-10, and rig my playlist so that anything under a 6 never plays unless I specifically select it, tracks rated 7 play twice as often as those rated 6, and the frequency keeps going up the higher my rating is. (I only have eight tracks rated as a 10, and they're all things I don't mind hearing back-to-back.) Then if I find a track is playing more often than I like, I figure I rated it too high and cut back its rating.
> See, from my POV (I'm an engineer), an analytic solution to Navier-Stokes > would be far more important.
I don't deny that applied math can be _important_. I only said that I find pure math more _interesting_. Plenty of things in this world are more interesting than important, or vice versa.
One thing you can do is to "seed" the system by giving certain trustworthy persons a larger number of (or possibly unlimited) mod points, and then make the number of mod points that any other person receives in a given timeframe contingent on their reputation or karma or whatever you call it, so that those who are frequently modded up get more mod points.
However, you really should look at the system Perlmonks uses, which is very effective. First, new posts appear only in "Newest Nodes" (i.e., not on the front page nor in their respective section) until they are approved; those who have reached a certain level of experience is permitted to do the approval. Beyond that, nodes which have major problems can be Considered for editing or even reaping -- sufficiently experienced persons can Consider a node and can vote on what should be done with it. Finally, there's the Experience system, which is somewhat analogous to slashdot's moderation, but the number of votes you get every day is contingent upon how much experience you have. It's a fairly complicated system, but it works very well.
I do think also that, depending on the nature of the forum, it can be useful to allow moderators to apply objective labels and then let the users determine how to interpret those labels. The slashdot system does this fairly well overall. I particularly like that I can go into my preferences and assign a different numeric value to certain labels (e.g., "Funny") to make posts that receive them more or less likely to be shown to me.
The set of specific labels it uses could use an overhaul, but in any case you're going to want to tailor that depending on the subject matter of the forum. For a political forum, for instance, I think I'd want posts to be able to be categorized as "Radical", "Liberal", "Moderate", "Progressive", "Conservative", or "Reactionary". For a religious discussion forum, I might want labels like "traditional" versus "progressive" or "creative" versus "orthodox", but these labels would not be appropriate on a forum dedicated to, say, linguistics.
OTOH, some labels might be useful irrespective of subject matter, e.g., , "clear" or "unclear" (referring to how well the ideas in the message are explained) and "on-topic" or "off-topic".
I tend also to think that if the subject matter is expected to be at all contentious, there should be an explicit "agree"/"disagree" mechanism, so that users can freely express that they agree or disagree. It won't completely eliminate abuse of the moderation system, but it might help, and in any case some people just love to be able to express that they agree or disagree with something, so it's good to accomodate that. Along with a post you might see a line like "16 people have agreed and 13 disagreed with this comment".
But you would use the moderation, not the agreement, to inform site functionality such as which comments are automatically expanded and how many votes any given user receives in a day.
Indeed. When it became evident that the Poincaire conjecture is not going to be considered an open problem much longer, my thoughts too were of the Reimann Hypothesis. Throughout most of the twentieth century those were widely considered to be the two biggest open problems in pure math, and it'd be really cool to see them both solved in our generation.
This Navier-Stokes thing seems to be more of an applied-math problem, and although I'm sure it's important, it's just not as exciting to me as the more abstract theoretical stuff of pure math.
We don't use those kinds of buzzers. We use the light pad sets from Quiz Time Systems, mostly. You don't hold anything in your hands. You sit on your pad, which has little switches in it, and when you get _off_ your pad, your light comes on if you're first. (If you're not first, the way the thing's wired keeps your light off until the other person sits on his pad again, so there's no question about who won the jump.) So the standard posture involves leaning forward, with all of your weight on your feet and calf muscles and just enough of your rear on the pad to keep the light off, watching the quizmaster's lips.
> Non-nerds usually consider The Voyage Home the best one (Non-Nerd: Is that the > one with the whales in it??). But I agree, The Undiscovered Country was great. > Kirk rules, Picard drools!
Insurrection is also sometimes liked by non-nerds.
I do like ST6:TUU, although the alusive quotes get a bit old after about the eightieth one. I disagree with the traditional odd/even rule, though: I actually rather liked ST3:TSFS, perhaps better than STIV:TVH. The worst, beyond any question, is STV:TFF, which is so terrible it frankly does not deserve even to be considered canon. I generally consider ST2:TWOK the best of the ones with Kirk, and either First Contact or Insurrection (I cannot decide which) the best of the ones with Picard. The trouble with ST:TMP is that the special effects were too large a part of the movie, and of course they have not aged well. The plot, as far as it goes, is not bad, there just needed to be more of it and fewer flashes of light.
I am not a big fan of Generations and am withholding judgement on Nemesis until I can put it in proper perspective. It may turn out to be a mixed bag. I *think* I agree with the decision to kill off Data, although of course it was heartbreaking, but it depends somewhat on what (if anything) they do subsequently with B4. If they handle that wrong (e.g., have B4 almost immediately become just like Data always was), it could end up being the lamest thing of all time. If they handle it *well*, however, B4 could be a good enough character to be worth the sacrifice of Data, and in some ways more, both because he's a new character, and also because he'd presumably be mostly emotionless, and the previous three movies had explored the emotion chip pretty fully already. The backstory behind Praetor Chinzon left something to be desired, and the theileron[1] radiation weapon was a terrible plot device, but OTOH I really liked the way the movie developed the Reman race and culture, and the major Romulan characters, notably the female captain, were also well portrayed and interesting IMO.
[1] I'm not sure how to spell that, having never seen it in print.
> I am struggling. I believe that I have a flaw in the basic way I think about > numbers. [...] Has there been any research or books on the difference between > how a mathematician, or a Richard Feynman, thinks about math and the way that > the average person thinks about math?
The difference is that an average person thinks math is all about performing various calculations with numbers, and a mathematician thinks math is about understanding the world.
I was lucky. I don't know if the teacher just explained it right, or if it just hit me, or what, but I got it in seventh grade: math isn't about numbers, at least, not mostly. Numbers are just a handy source of concrete examples. Most folks don't realize this until they get further along, at least to multi-variable algebra and more often after getting through Calculus. But it's an important realization, and it makes math much easier once you've grasped it. (In less than one year math went from being my worst subject, which I hated, to being my best subject, which I loved.) Math is about seeing the similarities between one situation and another -- isomorphisms -- and then determining whether what you know about one particular case is in fact a generality that applies in other cases as well. Math is about developing useful ways of understanding the world in which we live. Math is very cool, once you understand it.
Math is abstract. Concentrate on understanding the underlying theoretical concepts. Once you see the conceptual patterns and understand what is going on, the numbers will fall into place. Don't just memorize the rote method (at least, not most of the time): concentrate on figuring out *why* it is that way, and then you won't have any trouble remembering it (or improvising slight variations for special situations, or combining it with the stuff from other chapters).
> Memorizing large amounts of random information has more to do with effective > mnemonic techniques and capacity for intense concentration than base retentive
Innate ability does help, but mostly memorization is a learned skill.
I should know. I'm heavily involved with a quizzing program -- not the random-trivia type of quizzing, but the sort where they give you a particular text to study for a few weeks and all the questions come from that text. Naturally the best quizzers memorize the whole material. At the national level, practically all of the quizzers memorize the entire material, and the best ones know things like how many times certain words are used. (I know several of these best quizzers personally. I happen to live in the North Central Ohio district, which takes first place in the nation more often than any other district in the program.)
So as I said, innate ability helps, and especially it helps inherently somewhat brighter people to get "into" the program more quickly and get started more easily, but the quizzers who take home the trophies are not the ones who started out smartest; they're the ones who studied most and/or the ones who have been quizzing seriously for the most years. With *rare* exceptions, new quizzers don't start out memorizing. At first they read over the material every day and try to learn enough of it to answer some of the questions. Because certain sections of the material are designated for especial memorization, most quizzers eventually reach the point where they start memorizing at least those sections. After they've done a few, it gets easier. Nobody memorizes *all* of the memory sections the first time he memorizes everything. They start out with a few, and work their way up, until they're learning all of them. Like I said, it gets easier after you've done more of it. Once they reach the point of having memorized all of the memory sections, it's about a quarter of the whole material, so they start to realize then that they could just flat memorize all of it. In NCO we try not to put anybody on the district team (i.e., the team we send to nationals) unless they've reached the point where they're willing to seriously attempt that.
The quizzing program doesn't just teach memorization (although the learning of the text is an important goal for pretty much everyone involved). Because the quizzers have to answer questions, not just recite, and because they have to *finish* the question before they can answer it (assuming the quizmaster didn't already finish it, which at the higher levels of quizzing he almost never does, because invariably the level of competition is such that the quizzers are off their lights before the question is half done), there are other kinds of mental activity as well.
Incidentally, the quizzers in this program are kids and teens. I'm far too old to quiz these days, but I coach and I serve as quizmaster (i.e., ask the questions) and sometimes judge. I did quiz when I was younger, and I was on the district team in 1992.
Just because there's a correlation doesn't imply there's necessarily a direct cause/effect relationship. There are significant cultural differences between income brackets, and (assuming they did the study in North America) one of them is that the lower middle class income brackets do less moderate social drinking, possibly because they are closer to and more aware of the lower-class bracket, wherein drinking is mostly the province of boorish drunkards, whose habits and behavior are distasteful. Alcohol in the lower income brackets is therefore associated with a lot of unpleasantness. This is not absolute, but it's *mostly* true, at least in the Midwestern US.
The upper income brackets are another matter, and I'm not just talking about the CEO class. Once you get up into yuppee territory (more or less) you start finding people whose experience with alcohol is more moderate; they may order a glass of this or that with their dinner, for instance. In that culture, social drinking is less strongly associated with drunkenness and *much* less strongly associated with retching on oneself, being arrested, domestic violence, and the various other forms of yuckiness that seem to go hand-in-hand with alcohol in the lower income brackets. Additionally, there are higher-quality beverages available at pricepoints they can afford, so the alcohol can actually taste good, and consequently there are reasons to drink it other than getting drunk. In the lower income brackets you're pretty much looking at cheap American beer, which is pretty much only good for getting drunk. (Indeed, the way some of that stuff smells, I think I'd have to *be* drunk to *want* to put it in my mouth.)
So there's a cultural difference between the income brackets when it comes to alcohol, and I'd chalk up the correlation they found to that. Going out and drinking isn't necessarily going to get you that raise.
> It's true that not a lot of people write COBOL today, but the > submiter was talking about legacy code. No wonder they're not > on the Internet: not only they are from a pre-Internet era, > but the vast majority of it is from corporations that keep > their code very closed.
The amount of COBOL code out there has also been greatly exaggerated.
Almost all COBOL code in existence is 25+ years old, but at this point there is more new code written *every year* than the TOTAL amount of 25-year-old code still in use. (There's a lot of ten-year-old code still in use, of course, but these days most of that is not COBOL.) Sure, a lot of the outfits that were using computers 25 years ago still have some of their old code kicking around, but in terms of computer usage "a lot" back then did not mean the same thing as "a lot" now.
And anyway, the main reason there was so much COBOL code out there in the first place is because it *takes* so much code to *do* anything in COBOL. (I actually had a COBOL class in college. My first program, which was basically Hello World, was most of two pages when printed. Part of that is the fifty lines or so of up-front overhead attached to every program, but a lot of it was due to the inherent verbosity of the language. You can't print anything out without storing it in a variable. You can't store anything in a variable without declaring it, not once but twice, and its "picture" format. And so on.) A thousand lines of COBOL is roughly equivalent to a hundred lines or so of C, ten lines of decent maintainable Perl, or one line of Perl golfed down beyond all recognition.
Anyway, what I was going to say is that Perl has had search.cpan.org for a while, but it'd be nice to have comparable functionality for other languages, so one hopes they'll keep working on this.
> And if you have any chemical habits (e.g., caffein), kick them at least > two weeks before the test.
Exception: If you take Ritalin or caffein for ADHD, and you have difficulty sitting still without it, make sure you time your doses so that it does NOT wear off during the test.
> Does anyone have a link to a list of exactly what I am expected to know > and in what detail I need to know it
No.
The SATs are not intended to test what you know. They're intended to test how you think. A certain amount of knowledge _is_ necessary, mostly of math and English vocabulary, but it's your ability to figure stuff out that is being tested. It's not the sort of test you can cram for very effectively, if that's what you're asking. You'll see what I mean when you take the test.
Now, my experience is not with the SAT Reasoning test, but with the regular garden-variety college-entrance SATs that I took when I was applying to college, the ones people mean when they say "the SAT" without qualification. The analogies sections, for instance, aren't something you can directly study for, other than by learning enough vocabulary to know what the words mean. (I guess if you've got time to read through a big fat dictionary...) I suppose you could study better for the math sections, by boning up on your algebra and stuff, but even there it's pretty general. It's not like there's some grocery list of math techniques you're supposed to know; they just throw a lot of problems at you and see if you can solve some of them.
Nonetheless, I can't imagine that the Reasoning test would do less in terms of testing your reasoning ability and more in terms of testing knowledge, as compared with the regular SATs I took. I suspect rather the reverse.
If you want to take a college entrance test that goes after what you _know_, take the ACT. It tests your knowledge of four major academic subject areas, and there are study guides for it everywhere, and some of them are actually pretty decent, OSIAT. The SATs aren't geared that way. This doesn't stop every publisher on the planet from putting out study guides, of course, but I'm not convinced they'll improve your score much.
My recommendation is to get a good night's sleep the night before, get up at least an hour before you have to leave to go take the test, wake up thoroughly, and eat a good breakfast. Seriously.
And if you have any chemical habits (e.g., caffein), kick them at least two weeks before the test.
Re:Am I just being overly simplistic...
on
IPv6 Essentials
·
· Score: 1
> Or could the problem of supposedly running out of addresses be 'addressed' > (sorry) simply by adding another octet to IPv4?
Theoretically, but the result wouldn't be IPv4 and wouldn't be compatible with IPv4, so from a technical standpoint (in terms of hardware and software support and stuff) it's just as easy to move to IPv6.
From a user-retraining angle it would have been easier in the short term to keep things more similar to IPv4 (although I'd have said go with four sixteen-bit values, rather than five eight-bit values, partly because it means lots more addresses and partly because it keeps the x.x.x.x format, only x is allowed to be larger numbers). But if you've ever calculated the subnet mask for a network with a nonstandard number of host bits, you'd understand why they wanted to go with a system that expresses the addresses in hex rather than decimal. Five minutes of retraining there will save you much pain later. I imagine some of the other changes seemed similarly sensible, though I haven't studied the details.
> The game illustrates a warning by Iran's supreme leader Ayatollah Ali Khamenei, > who said in June that oil exports in the Gulf region could be seriously endangered > if the United States made a wrong move on Iran
Eh. Maybe he intended that as a threat, maybe not. Either way, the best way to deal with it is to give him the benefit of the doubt and assume it's not a threat. Such an action would only *harm* Iran (as well as some other nations that also ship oil and stuff through there) and would gain them nothing, and it would harm Iran far more than it would harm the US. If I were developing the official US position on his statement, my interpretation would be that he apparently believes the US might itself do something to endanger oil exports (e.g., by using more domestic oil and importing less), and that the Iranian government would interpret such an action as a "wrong move". That would be a much more sensible and coherent position than the one the article seems to imply he is taking.
As a terrorist threat, disrupting the Strait of Hormuz wouldn't even be scary, except to a handful of Arab nations. If a threat of terrorism was what he intended, wouldn't he at least have threatened the Suez? That would at least worry Europe, economically speaking, and would be more worrisome to the US than threatening Persian Gulf shipping.
Not that there wouldn't be an impact at all. I mean sure, the price of oil would go up a bit, for a few months. But it would be no worse than they could accomplish by just reducing their oil production and selling less (or none), if they were willing to do so. Gas would probably go up again, but we'd live through it. Iran's economy would be in much more dire straits (no pun intended).
Slashdot Mirror
> Yes, but if it repeats that sequence every 6000 years, it really doesn't matter.
True, but...
> Modern pseudorandom alorithms are very good.
Not in this context. Pseudorandom algorithms approximate *mathematical* randomness.
> This completely ignores the issue at hand, which is that randomness is not
> what people want anyway.
Exactly. People think they want "random", but they don't want mathematical random. They want things carefully and thoroughly mixed up in an approximately _even_ distribution with no proximate repeats and no naturally-ordered subsequences of any significant length, among other things.
> I think the lesson here is that you should never use a mathematically
> random algorithm for [a]esthetic purposes.
You can use a standard rand() function as a starting point, but you have to fudge the results considerably. Also, using rand() is not the only way to achieve random. I have a program that generates twenty-question quizzes from a large bank of questions. For some things (e.g., selecting which questions to use) it uses rand() as a starting point and then fudges in various ways (e.g., tossing out questions whose answer references the same place in the source text as a question that has already been selected), but once it has selected which twenty questions it's going to use, it goes into decidedly-not-mathematically random mode to determine how to order them. Basically, it extracts the four special questions (two finish questions and two reference questions) and places one of them in each of four five-question quarter-quizzes, then it *sorts* the normal questions according to the order of their references and puts the first one in the first quarter, the second in the second quarter, and so on (wrapping around to the first quarter after the fourth). It does then randomorder each quarter and subsequently does a little more fudging (e.g., to make sure that the first and last questions of the quiz are not special questions)...
> For my "scramble_case" I weighted the probability against getting a
> capitalized first letter, because that looks Too Normal.
Yes, that's exactly the sort of thing I'm talking about. If half or more of the words started with a capital letter, the scrambling wouldn't look "random" enough. It's a real paradigm shift from the meaning of random in computer science 101. It's the same reason my quiz generator must guarantee that the first question and the last question of the quiz are neither one ever a finish nor a reference question, even though with a mathematically random arrangement they (each) would be about a fifth of the time, over the long term. But if it happens even once, people complain that the quizzes aren't random and we should get a computer to do them. Most of the quizzers assume they're arranged by hand, but that would be a lot of work. However, even with all of the fudging I have built into the program, I still have to look over the quizzes before each rally and check that nothing went wrong and the quizzes are "random" enough. It just wouldn't do to have e.g. five "Why" questions in a row or some such oddity.
> However, we, in the US, have this little thing called the first amendment. The right to
> free speech. What Spamhaus (or rather, the email server admin) does is interfere with
> end users ability to receive free speech.
No. The stuff Spamhaus publishes does happen to be information that users or mail admins can use to decide which "speech" (in the form of email) they wish to listen to, but Spamhaus does not itself prevent anyone from receiving anything.
> This, in theory, should be up to the end user to OK.
No, it's up to the owner or administrator of the receiving mail server. They get to decide what information ("speech") may be published via their server, just as a newspaper publisher gets to decide which letters to the editor they want to publish, and if you write one and send it to them and they file it permanently, or for that matter shred and burn it, you have no valid complaint.
If the reader of the newspaper doesn't like this, he can buy a different paper, or, on the other side of the analogy, get email service from a different provider. (I do think ISPs should be up-front with their users about what services and techniques they use to limit spam, although frankly most end users are not deeply concerned with the technical details.)
If the writer of the letter, or the spammer, is unhappy with this arrangement, he can jolly well start his own newspaper (or mail service) and try to convince people to subscribe to it.
Personally, I'm not a large fan of blacklist-based approaches to limiting spam, but fundamentally it's up to the owner or administrator of the mail server, and Spamhaus is just offering advice.
The real problem in the legal case, according to one of the linked articles, appears to be one of jurisdiction or, more particularly, that Spamhaus apparently agreed to go to trial in the US and then backed out on it later. If that's true, it sounds like a pretty big mistake that will probably cost them.
Yes, I think the reported who wrote up the article didn't fully understand the research that was being done. The point of the research is to look at what kinds of attacks are out there and, especially, which ones are common, as it helps security people to know better how to protect against them. The most important take-home message from this article, as near as I can tell, is don't connect a Windows XP system to the network without SP2. I knew that already (actually, I have a strong preference for an external firewall), but that doesn't make it less valid. If I were Microsoft my response would be to say, "See, this is why you need to turn on your Windows Firewall, like we recommend, and stay up-to-date with patches, like we recommend. This is why we put the Security Center in SP2."
The biggest problem here is that home users with OEM versions of XP that predate SP2 can run into trouble when they have to reinstall (not as frequent with XP as it was with Win9x but it does still happen from time to time). The most obvious solution is an external firewall.
> There is no randomness in computers.
I don't know what's available on the iPod hardware, but in a desktop scenario, I generally multiply the pseudorandom number from whatever standard rand function is available by the hundredth-of-a-second value off the system clock and then use modular arithmetic to get the result in the range I need. This is almost certainly not cryptographically sound, but it is good enough to seem unpredictable to most humans, so it's a good start for things like shuffling a playlist or pulling questions from a test bank.
You generally still want to fudge the results in various ways to make them appear more "random" to the user, though. It's easy to seem unpredictable, but you have to work a bit more to achieve "random". (Note here that I am using "random" here in the sense end users generally understand it, *not* in the math/programmer jargon sense. Even when I do various fudgings to make the results seem more "random", I still avoid using the _word_ "random", because that word sets the users' expectations pretty high, and I'm usually not that confident in my fudging algorithms.
> And in any event, the benefit of making the book searchable is dubious given
> that the DRM could be used to limit your ability to search it, that searching
> isn't really important for some books (e.g. most works of fiction)
Actually, I *frequently* find myself flipping back through earlier pages of a work of fiction, looking for an earlier reference to something, trying to remind myself of certain details. I would be very pleased to have all books be searchable.
I am not, however, entirely sure what this has to do with Windows Vista. Hopefully nothing, because although I'd like to have my books be searchable, I don't think I want to switch operating systems on my computer to get there.
Except for mathematicians and programmers, most think of "random" in a *very* different way from its technical definition. To most humans, saying that a particular sequence is "random" means *guaranteeing* certain things about it. Among them: the same element does not occur back-to-back, EVER, even if there are only a few elements total to choose from. Even more, if there are more than about half a dozen elements, the same element never occurs twice within about five positions. (So if you've got songs 1 through 7 on your iPod, and the first seven played are 5, 3, 7, 2, 4, 1, 6, then the next one has to be 5 or 3, or _maybe_ 7, or it doesn't seem "random" to most people. Yet, the order can't be the same every time through, either.) No element occurs substantially more often than any other element, even over the short term. If the elements have a natural order (e.g., alphabetical), then no three elements that are adjascent in that order can ever occur together in that order, nor should they occur together in the reverse order. (This gets particularly difficult to guarantee when the elements have more than one natural order, e.g., if the elements are people, you can't have three of them in a row by either name or age, or people notice and decide that the order is not random.) Even worse, if the elements can all be categorized into a small number of categories (e.g., by gender), you can't have "too many" from one category in a row. (How many is too many depends on the ratio, but if half of the elements are male and half female, having four of either in a row will make people cry foul, the order is not "random".) If certain elements stand out from the others in some significant way, they can neither occur first nor last. (For instance, if test questions are being drawn from a question bank, neither the easiest nor the hardest question should be first or last; if it is, people will say the order was not random.)
I could go on and on, but what it really amounts to is that when most people say "random" they mean "carefully arranged in a thoroughly mixed-up order". This is almost the *opposite* of what a mathematician or computer programmer thinks the word "random" means.
For this reason, when describing a mathematically-random sequence to an end user, I never EVER use the word "random". I generally call it something like "arbitrary" or "unpredictable". This greatly reduces complaints.
Now, as far as song frequency, I like to rate my tracks on a scale of 1-10, and rig my playlist so that anything under a 6 never plays unless I specifically select it, tracks rated 7 play twice as often as those rated 6, and the frequency keeps going up the higher my rating is. (I only have eight tracks rated as a 10, and they're all things I don't mind hearing back-to-back.) Then if I find a track is playing more often than I like, I figure I rated it too high and cut back its rating.
> See, from my POV (I'm an engineer), an analytic solution to Navier-Stokes
> would be far more important.
I don't deny that applied math can be _important_. I only said that I find pure math more _interesting_. Plenty of things in this world are more interesting than important, or vice versa.
One thing you can do is to "seed" the system by giving certain trustworthy persons a larger number of (or possibly unlimited) mod points, and then make the number of mod points that any other person receives in a given timeframe contingent on their reputation or karma or whatever you call it, so that those who are frequently modded up get more mod points.
However, you really should look at the system Perlmonks uses, which is very effective. First, new posts appear only in "Newest Nodes" (i.e., not on the front page nor in their respective section) until they are approved; those who have reached a certain level of experience is permitted to do the approval. Beyond that, nodes which have major problems can be Considered for editing or even reaping -- sufficiently experienced persons can Consider a node and can vote on what should be done with it. Finally, there's the Experience system, which is somewhat analogous to slashdot's moderation, but the number of votes you get every day is contingent upon how much experience you have. It's a fairly complicated system, but it works very well.
I do think also that, depending on the nature of the forum, it can be useful to allow moderators to apply objective labels and then let the users determine how to interpret those labels. The slashdot system does this fairly well overall. I particularly like that I can go into my preferences and assign a different numeric value to certain labels (e.g., "Funny") to make posts that receive them more or less likely to be shown to me.
The set of specific labels it uses could use an overhaul, but in any case you're going to want to tailor that depending on the subject matter of the forum. For a political forum, for instance, I think I'd want posts to be able to be categorized as "Radical", "Liberal", "Moderate", "Progressive", "Conservative", or "Reactionary". For a religious discussion forum, I might want labels like "traditional" versus "progressive" or "creative" versus "orthodox", but these labels would not be appropriate on a forum dedicated to, say, linguistics.
OTOH, some labels might be useful irrespective of subject matter, e.g., , "clear" or "unclear" (referring to how well the ideas in the message are explained) and "on-topic" or "off-topic".
I tend also to think that if the subject matter is expected to be at all contentious, there should be an explicit "agree"/"disagree" mechanism, so that users can freely express that they agree or disagree. It won't completely eliminate abuse of the moderation system, but it might help, and in any case some people just love to be able to express that they agree or disagree with something, so it's good to accomodate that. Along with a post you might see a line like "16 people have agreed and 13 disagreed with this comment".
But you would use the moderation, not the agreement, to inform site functionality such as which comments are automatically expanded and how many votes any given user receives in a day.
Indeed. When it became evident that the Poincaire conjecture is not going to be considered an open problem much longer, my thoughts too were of the Reimann Hypothesis. Throughout most of the twentieth century those were widely considered to be the two biggest open problems in pure math, and it'd be really cool to see them both solved in our generation.
This Navier-Stokes thing seems to be more of an applied-math problem, and although I'm sure it's important, it's just not as exciting to me as the more abstract theoretical stuff of pure math.
We don't use those kinds of buzzers. We use the light pad sets from Quiz Time Systems, mostly. You don't hold anything in your hands. You sit on your pad, which has little switches in it, and when you get _off_ your pad, your light comes on if you're first. (If you're not first, the way the thing's wired keeps your light off until the other person sits on his pad again, so there's no question about who won the jump.) So the standard posture involves leaning forward, with all of your weight on your feet and calf muscles and just enough of your rear on the pad to keep the light off, watching the quizmaster's lips.
> Non-nerds usually consider The Voyage Home the best one (Non-Nerd: Is that the
> one with the whales in it??). But I agree, The Undiscovered Country was great.
> Kirk rules, Picard drools!
Insurrection is also sometimes liked by non-nerds.
I do like ST6:TUU, although the alusive quotes get a bit old after about the eightieth one. I disagree with the traditional odd/even rule, though: I actually rather liked ST3:TSFS, perhaps better than STIV:TVH. The worst, beyond any question, is STV:TFF, which is so terrible it frankly does not deserve even to be considered canon. I generally consider ST2:TWOK the best of the ones with Kirk, and either First Contact or Insurrection (I cannot decide which) the best of the ones with Picard. The trouble with ST:TMP is that the special effects were too large a part of the movie, and of course they have not aged well. The plot, as far as it goes, is not bad, there just needed to be more of it and fewer flashes of light.
I am not a big fan of Generations and am withholding judgement on Nemesis until I can put it in proper perspective. It may turn out to be a mixed bag. I *think* I agree with the decision to kill off Data, although of course it was heartbreaking, but it depends somewhat on what (if anything) they do subsequently with B4. If they handle that wrong (e.g., have B4 almost immediately become just like Data always was), it could end up being the lamest thing of all time. If they handle it *well*, however, B4 could be a good enough character to be worth the sacrifice of Data, and in some ways more, both because he's a new character, and also because he'd presumably be mostly emotionless, and the previous three movies had explored the emotion chip pretty fully already. The backstory behind Praetor Chinzon left something to be desired, and the theileron[1] radiation weapon was a terrible plot device, but OTOH I really liked the way the movie developed the Reman race and culture, and the major Romulan characters, notably the female captain, were also well portrayed and interesting IMO.
[1] I'm not sure how to spell that, having never seen it in print.
Actually, quizzing is a lot of fun. We have a blast at rallies.
It does, however, also require a bit of work. Nothing worth having is easy.
> I am struggling. I believe that I have a flaw in the basic way I think about
> numbers. [...] Has there been any research or books on the difference between
> how a mathematician, or a Richard Feynman, thinks about math and the way that
> the average person thinks about math?
The difference is that an average person thinks math is all about performing various calculations with numbers, and a mathematician thinks math is about understanding the world.
I was lucky. I don't know if the teacher just explained it right, or if it just hit me, or what, but I got it in seventh grade: math isn't about numbers, at least, not mostly. Numbers are just a handy source of concrete examples. Most folks don't realize this until they get further along, at least to multi-variable algebra and more often after getting through Calculus. But it's an important realization, and it makes math much easier once you've grasped it. (In less than one year math went from being my worst subject, which I hated, to being my best subject, which I loved.) Math is about seeing the similarities between one situation and another -- isomorphisms -- and then determining whether what you know about one particular case is in fact a generality that applies in other cases as well. Math is about developing useful ways of understanding the world in which we live. Math is very cool, once you understand it.
Math is abstract. Concentrate on understanding the underlying theoretical concepts. Once you see the conceptual patterns and understand what is going on, the numbers will fall into place. Don't just memorize the rote method (at least, not most of the time): concentrate on figuring out *why* it is that way, and then you won't have any trouble remembering it (or improvising slight variations for special situations, or combining it with the stuff from other chapters).
> Memorizing large amounts of random information has more to do with effective
> mnemonic techniques and capacity for intense concentration than base retentive
Innate ability does help, but mostly memorization is a learned skill.
I should know. I'm heavily involved with a quizzing program -- not the random-trivia type of quizzing, but the sort where they give you a particular text to study for a few weeks and all the questions come from that text. Naturally the best quizzers memorize the whole material. At the national level, practically all of the quizzers memorize the entire material, and the best ones know things like how many times certain words are used. (I know several of these best quizzers personally. I happen to live in the North Central Ohio district, which takes first place in the nation more often than any other district in the program.)
So as I said, innate ability helps, and especially it helps inherently somewhat brighter people to get "into" the program more quickly and get started more easily, but the quizzers who take home the trophies are not the ones who started out smartest; they're the ones who studied most and/or the ones who have been quizzing seriously for the most years. With *rare* exceptions, new quizzers don't start out memorizing. At first they read over the material every day and try to learn enough of it to answer some of the questions. Because certain sections of the material are designated for especial memorization, most quizzers eventually reach the point where they start memorizing at least those sections. After they've done a few, it gets easier. Nobody memorizes *all* of the memory sections the first time he memorizes everything. They start out with a few, and work their way up, until they're learning all of them. Like I said, it gets easier after you've done more of it. Once they reach the point of having memorized all of the memory sections, it's about a quarter of the whole material, so they start to realize then that they could just flat memorize all of it. In NCO we try not to put anybody on the district team (i.e., the team we send to nationals) unless they've reached the point where they're willing to seriously attempt that.
The quizzing program doesn't just teach memorization (although the learning of the text is an important goal for pretty much everyone involved). Because the quizzers have to answer questions, not just recite, and because they have to *finish* the question before they can answer it (assuming the quizmaster didn't already finish it, which at the higher levels of quizzing he almost never does, because invariably the level of competition is such that the quizzers are off their lights before the question is half done), there are other kinds of mental activity as well.
Incidentally, the quizzers in this program are kids and teens. I'm far too old to quiz these days, but I coach and I serve as quizmaster (i.e., ask the questions) and sometimes judge. I did quiz when I was younger, and I was on the district team in 1992.
Just because there's a correlation doesn't imply there's necessarily a direct cause/effect relationship. There are significant cultural differences between income brackets, and (assuming they did the study in North America) one of them is that the lower middle class income brackets do less moderate social drinking, possibly because they are closer to and more aware of the lower-class bracket, wherein drinking is mostly the province of boorish drunkards, whose habits and behavior are distasteful. Alcohol in the lower income brackets is therefore associated with a lot of unpleasantness. This is not absolute, but it's *mostly* true, at least in the Midwestern US.
The upper income brackets are another matter, and I'm not just talking about the CEO class. Once you get up into yuppee territory (more or less) you start finding people whose experience with alcohol is more moderate; they may order a glass of this or that with their dinner, for instance. In that culture, social drinking is less strongly associated with drunkenness and *much* less strongly associated with retching on oneself, being arrested, domestic violence, and the various other forms of yuckiness that seem to go hand-in-hand with alcohol in the lower income brackets. Additionally, there are higher-quality beverages available at pricepoints they can afford, so the alcohol can actually taste good, and consequently there are reasons to drink it other than getting drunk. In the lower income brackets you're pretty much looking at cheap American beer, which is pretty much only good for getting drunk. (Indeed, the way some of that stuff smells, I think I'd have to *be* drunk to *want* to put it in my mouth.)
So there's a cultural difference between the income brackets when it comes to alcohol, and I'd chalk up the correlation they found to that. Going out and drinking isn't necessarily going to get you that raise.
> It's true that not a lot of people write COBOL today, but the
> submiter was talking about legacy code. No wonder they're not
> on the Internet: not only they are from a pre-Internet era,
> but the vast majority of it is from corporations that keep
> their code very closed.
The amount of COBOL code out there has also been greatly exaggerated.
Almost all COBOL code in existence is 25+ years old, but at this point there is more new code written *every year* than the TOTAL amount of 25-year-old code still in use. (There's a lot of ten-year-old code still in use, of course, but these days most of that is not COBOL.) Sure, a lot of the outfits that were using computers 25 years ago still have some of their old code kicking around, but in terms of computer usage "a lot" back then did not mean the same thing as "a lot" now.
And anyway, the main reason there was so much COBOL code out there in the first place is because it *takes* so much code to *do* anything in COBOL. (I actually had a COBOL class in college. My first program, which was basically Hello World, was most of two pages when printed. Part of that is the fifty lines or so of up-front overhead attached to every program, but a lot of it was due to the inherent verbosity of the language. You can't print anything out without storing it in a variable. You can't store anything in a variable without declaring it, not once but twice, and its "picture" format. And so on.) A thousand lines of COBOL is roughly equivalent to a hundred lines or so of C, ten lines of decent maintainable Perl, or one line of Perl golfed down beyond all recognition.
Anyway, what I was going to say is that Perl has had search.cpan.org for a while, but it'd be nice to have comparable functionality for other languages, so one hopes they'll keep working on this.
> And if you have any chemical habits (e.g., caffein), kick them at least
> two weeks before the test.
Exception: If you take Ritalin or caffein for ADHD, and you have difficulty sitting still without it, make sure you time your doses so that it does NOT wear off during the test.
> Does anyone have a link to a list of exactly what I am expected to know
> and in what detail I need to know it
No.
The SATs are not intended to test what you know. They're intended to test how you think. A certain amount of knowledge _is_ necessary, mostly of math and English vocabulary, but it's your ability to figure stuff out that is being tested. It's not the sort of test you can cram for very effectively, if that's what you're asking. You'll see what I mean when you take the test.
Now, my experience is not with the SAT Reasoning test, but with the regular garden-variety college-entrance SATs that I took when I was applying to college, the ones people mean when they say "the SAT" without qualification. The analogies sections, for instance, aren't something you can directly study for, other than by learning enough vocabulary to know what the words mean. (I guess if you've got time to read through a big fat dictionary...) I suppose you could study better for the math sections, by boning up on your algebra and stuff, but even there it's pretty general. It's not like there's some grocery list of math techniques you're supposed to know; they just throw a lot of problems at you and see if you can solve some of them.
Nonetheless, I can't imagine that the Reasoning test would do less in terms of testing your reasoning ability and more in terms of testing knowledge, as compared with the regular SATs I took. I suspect rather the reverse.
If you want to take a college entrance test that goes after what you _know_, take the ACT. It tests your knowledge of four major academic subject areas, and there are study guides for it everywhere, and some of them are actually pretty decent, OSIAT. The SATs aren't geared that way. This doesn't stop every publisher on the planet from putting out study guides, of course, but I'm not convinced they'll improve your score much.
My recommendation is to get a good night's sleep the night before, get up at least an hour before you have to leave to go take the test, wake up thoroughly, and eat a good breakfast. Seriously.
And if you have any chemical habits (e.g., caffein), kick them at least two weeks before the test.
> Or could the problem of supposedly running out of addresses be 'addressed'
> (sorry) simply by adding another octet to IPv4?
Theoretically, but the result wouldn't be IPv4 and wouldn't be compatible with IPv4, so from a technical standpoint (in terms of hardware and software support and stuff) it's just as easy to move to IPv6.
From a user-retraining angle it would have been easier in the short term to keep things more similar to IPv4 (although I'd have said go with four sixteen-bit values, rather than five eight-bit values, partly because it means lots more addresses and partly because it keeps the x.x.x.x format, only x is allowed to be larger numbers). But if you've ever calculated the subnet mask for a network with a nonstandard number of host bits, you'd understand why they wanted to go with a system that expresses the addresses in hex rather than decimal. Five minutes of retraining there will save you much pain later. I imagine some of the other changes seemed similarly sensible, though I haven't studied the details.
> Will it be here before or after viable fusion? What about DNF?
After Perl6, Emacs 23, room-temperature superconductors, cold fusion, and maybe even Vista, but before DNF.
HTH.HAND.
In that case, how about some authentic bona fide literal trusted QoS?
HTH.HAND.
> The game illustrates a warning by Iran's supreme leader Ayatollah Ali Khamenei,
> who said in June that oil exports in the Gulf region could be seriously endangered
> if the United States made a wrong move on Iran
Eh. Maybe he intended that as a threat, maybe not. Either way, the best way to deal with it is to give him the benefit of the doubt and assume it's not a threat. Such an action would only *harm* Iran (as well as some other nations that also ship oil and stuff through there) and would gain them nothing, and it would harm Iran far more than it would harm the US. If I were developing the official US position on his statement, my interpretation would be that he apparently believes the US might itself do something to endanger oil exports (e.g., by using more domestic oil and importing less), and that the Iranian government would interpret such an action as a "wrong move". That would be a much more sensible and coherent position than the one the article seems to imply he is taking.
As a terrorist threat, disrupting the Strait of Hormuz wouldn't even be scary, except to a handful of Arab nations. If a threat of terrorism was what he intended, wouldn't he at least have threatened the Suez? That would at least worry Europe, economically speaking, and would be more worrisome to the US than threatening Persian Gulf shipping.
Not that there wouldn't be an impact at all. I mean sure, the price of oil would go up a bit, for a few months. But it would be no worse than they could accomplish by just reducing their oil production and selling less (or none), if they were willing to do so. Gas would probably go up again, but we'd live through it. Iran's economy would be in much more dire straits (no pun intended).
> I prefer to destroy the hard disk physically myself, and sleep well at night
If your personal info is that dangerous in the wrong hands, you should maybe look into encrypted filesystems.
> If you don't use the computer very often, the hard drive will last a long time.
Is *that* why I've had such terrible luck with hard drives lately? Hmmm...