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2001/2/9-10 [Politics/Foreign] UID:20543 Activity:moderate |
2/8 Anybody tried mailing seeds outside the country? Do most countries allow this? I'm sending some seeds to Tunisia, but I'm asking about this in general. Thanks. \_ I don't know about shipping seeds out of the country, but I have received seeds from out of the country (Chile) just fine. \_ most countries will have SERIOUS problem when they got seeds from foreign country. The proper route is to go through custom, and it WILL take forever. When you sending the seeds out, I doubt U.S. is going to have problem with that, but you better check on Tunisia. \_ Agree that the legal way is to go through customs. But, I would sooner just send them in a regular envelope, and take my chances. How are you going to contact the Tunisia plant permit people, anyway? \_ I also received seeds just fine from the Netherlands. How will anyone know there are seeds in there unless you're sending enough for them to sow a whole field? --dim |
2001/2/9-10 [Computer/SW/Languages/Java] UID:20544 Activity:high |
2/8 can someone please recommend a beginning java book for someone who's only programming experience is equivalent to 61a? thanks. \_ Just Java by Van der Linden is pretty good. \_ "Thinking In Java" is almost too verbose. like having your hand held every step of the way. available online, for free. google. type "thinking in java bruce" \_ Just Java by Peter Van der Linden \_ thank you. this is the first time i've gotten a straight answer on the motd. \_ so all the previous motd answers are gay? |
2001/2/9 [Computer/SW/OS/Solaris] UID:20545 Activity:nil |
2/8 How do I find or calculate the total number of processes a Solaris |
2001/2/9 [Computer/HW/Memory] UID:20546 Activity:kinda low |
2.8 box can run before running out? \_ Run out of what? If you mean memory, there is no simple answer - it depends on how much RAM & swap you have and how much each process uses. -alan- \_ 2.8 same as pre-2.8 (except ptys are dynamically alloc'd) Examine with: sysdef -i or # adb -k /dev/ksyms /dev/mem parameter-name/D ^D (to exit) or # /etc/crash > od -d parameter-name > var where parameter-name is: maxusers, maxnprocs, or maxnuprc 2.8 can do >30K processes by modifying several params(bet its buggy) Put set pidmax=999999 in /etc/system modify pre-2.8 formulas: max_nprocs = ( 10 + 16 * maxusers ) ==> procs system-wide maxuprc = ( max_nprocs - 5 ) ==> procs per user & 5 reserved for root but can be modified. See http://docs.sun.com for real details -- I'm just guessing. |
2001/2/9-11 [Computer/Theory] UID:20547 Activity:high |
2/8 I have 20 positive numbers and five desired totals (all floating point numbers). I need to pick five mutually exclusive sets (not necessarily exhausive) of numbers from the 20 numbers, and then sum up the numbers in the five sets to get five totals. My goal is to minimize the mean-of-squares of the differences between the five totals and the five desired totals. I wrote a C program to do the brute-force try-all- combinations method (that's (5+1)^20 combinations), and it looks like it's going to need ~120 years of CPU time on my P-II 350MHz! Is there any better algorithm for doing this kind of things? Thanks. -- yuen \_ why isn't it 20!/(20-5)! ? \_ This is known as a 'bin packing problem.' It is NP-hard (in other words it is at least as hard as any problem in NP). -- ilyas \_ exclusive means (20! / (5! * (20-5)!)) right? \_ No, that would be the # of combinations to pick one set of five numbers from the 20 numbers. But in my case I need to pick five exclusive (ie. non-overlapping) sets instead of one, and each set can contain anywhere from zero to 20 numbers. -- yuen \_ Can you use an approximate solution? I think of this problem as being more similar to integer programming. It's equivalent to min_A ||Ax-b||^2, such that 1^T A <= 1, where x is your vector of 20 positive numbers, b is the five desired sum, and A is a 5x20 matrix with the entries constrained to be either zero or 1. You won't be able to reach the exact global optimum in poly time, but perhaps you can try adding an L_1 constraint to the objective? i.e. min_A ||Ax-b||^2 + lambda*sum_ij |A_ij|, s.t. 1^T A <= 1 L_1 penalty punishes any non-zero values, so A will have as many non-zero values as possible. Of course you're still left with the problem of deciding which entries of A to clamp to 1... Uh, need more optimization fu. -- alice \_ If my memory serves me right, LP relaxation isn't all that great for bin-packing. The first reference point to check would be _Approximation_Algorithms_For_NP-Hard_Problems_, edited by Dorit Hochbaum: http://www.ieor.berkeley.edu/~hochbaum/html/book-aanp.html It should be available at any university library by now. Chapter 2, written by Coffman, Garey, and Johnson (yes, THOSE Garey and Johnson), is "Approximation Algorithms for Bin Packing: A Survey" -alexf \_ I'm not up to date with NP approximation algorithms, but LP might be the easiest (and most practical) to implement than more complicated methods. BTW, one can express 0/1 constraints using (2A_ij-1)^2 = 1. The problem then is no longer LP, but you can get a lower bound using Lagrange relaxation (i.e. switching min & max), then use gradient descent or something on the lower bound function, which is usually much more tame than the original problem. This all sounds very complicated but is actually doable. I just don't know how good the approximation is. Maybe the book will say something about it. -- alice \_ Thanks for all the suggestions. Understanding what you all said is already hard enough. Gotta refresh my 170-series knowledge first before I go from here. -- yuen \_ can you think of a useful lower bound for what you're suggesting? you are talking about lower bounding |Ax-b|^2 + l*(|2A-1|^2-1) right? I'd bet that your regularization term smooths out the surface so much that you could just solve this using gradient descent. that you could just solve this using newton raphson. \_ this is one smart broad. |
2001/2/9 [Computer/SW/Security] UID:20548 Activity:very high |
2/8 Question about ssh or need confirmation. - purpose of using ssh is to avoid information that I read at my terminal not being seen by someone in between the traffic, so does that mean if my terminal is being mornitored (i.e., my employer or network admin is watching my console at a remote terminal), they will only see garbled messages? - or does ssh only ensures data send between soda and my terminal not being intercepted, but once information gets displayed on my screen, a mornitoring agent can just capture the screen and still see every key stroke I type in or every message I am reading? \_ work on your fucking english \_ hahhaha...having a hard time reading? I don't see the others have any problem. Can you just point out one flaw so that I can fix it. \_ double negative, run-on sentence, fragmentary phrase, passive voice, misspelling. And that's just the first sentence. \_ ssh encrypts data on the network between your host and wherever you ssh to ( in this case, soda). If your host has been compromised by whomever might be monitoring you, there is little ssh (or anything else for that matter) can do to stop you from being monitored. \_ here's what I do at work: swap around the keycaps on my keyboard. You should see the security people tearing their hair out! muahhaha! \_ how does that help really? \_ security through obscurity. though the right way to do this is to use a qwerty keyboard in dvorak mode. and remove the 'W'. |
2001/2/9-10 [Computer/SW/Mail] UID:20549 Activity:high |
2/9 Let's say I have two UNIX accounts. Is there .forward some trick that I can do (without the infinite loop) such that the email received at both accounts can be accessed at either account? \_ "man procmailex" and look for: "Suppose you have two accounts, you use both accounts regularly, but they are in very distinct places" \_ you don't need procmail if both of the servers involved are running sendmail. If your accounts are foo@bar and baz@garply, put this in .forward on foo@bar: \foo \baz@garply and this in .forward on baz@garply: \baz \foo@bar Note that this may not work without sendmail, since other MTAs may ignore backslashed email addresses on incoming mail. -alexf \_ uh, it also will create an infinite loop. good job. \_ This also doesn't let you filter the mail. Procmail's solution is more general. \_ Thanks! It works great, though some tweaking was necessary due to some odd configuration on one of the servers (piping to sendmail didn't work). |
2001/2/9-10 [Computer/SW/Unix] UID:20550 Activity:low |
2/8 Do you use RXVT instead of xterm? You should. -ali \_ RXVT- that's almost like RSVP. you know like 10. Spatz's. \_ Why? I actually use tektronix mode and like xterm's configuration a little better (e.g. bold actually works by default) \_ i think you're cool for using tektronix mode, whoever you are. i just checked this bold thing. it works fine for me. what's the problem exactly? -ali \_ no problem. I may agree with your logic, but I simply don't like your condescending tone and I don't like you. \_ that's fine. my superior ability to love transcends your petty feelings. use rxvt. -ali |
2001/2/9-10 [Computer/SW/OS/FreeBSD] UID:20551 Activity:moderate |
2/9 I'm Trying to add sound to FreeBSD 4.2- the handbook says that I have to check /dev/sndstat after recompiling and rebooting for FreeBSD Audio Driver (newpcm) Sep 21 2000 18:29:53 Installed devices: pcm0: <Aureal Vortex 8830> at memory 0xfeb40000 irq 5 (4p/1r +channels duplex) /dev/sndstat doesn't exist, but the pcm0 ID does show up in dmesg. man pages for sndstat are nil, what do I do? \_ cd /dev && ./MAKEDEV snd0 \_ Thanks, I just skipped ahead and did that. Now how do I mount a CDROM drive full of mp3s? \_ mkdir /mnt/cd && mount /dev/acd0c /mnt/cd \ I got an incorrect superblock doing that. mount_cd9660 /dev/acd0c /mnt/cd did work though. Thx \_ mount -t cd9660 blahblahblah |
2001/2/9-11 [Computer/SW/Languages, Computer/SW/Unix] UID:20552 Activity:nil |
2/9 How do you do multilevel command substitution? For example, echo `echo `echo `echo hello``` But how do you escape the `? Also how do you print ' within ', without using "? For example, echo ' \' ' (escape doesn't work) \_ In sh (or ksh or bash), echo $(echo $(echo hello)). In any shell, echo 'here'\''s how' |
2001/2/9-10 [Recreation/Dating] UID:20553 Activity:very high |
2/9 I know a 25-year old female EE grad student from China, who wears a red ring on her left-hand ring finger. What does this mean? \_ it means she is married to a Triad leader and has a wide variety of superpowers. \_ why not ask her and find out! \_ because he's a pussy! \_ that's too obvious and makes too much sense. try again. \_ It means she's married. The red color is probably just for fashion and has no special meaning. But let us know after you ask her. Is she hot? Pics? and has no special meaning. \_ Of course, she could just be wearing it to discourage clueless, desperate geeks from hitting on her all the time. A friend of mine who worked as a waitress at a cocktail bar did that all the time. mine who worked as a waitress at a cocktail bar used that ploy. \_ Geek ward? \_ Pics? \_ No Pics for you! |
2001/2/9-10 [Computer/SW/Security] UID:20554 Activity:nil |
2/9 ssh has vunerability. Integer overflow. Openssh is safe. \_ Take that, Tom! Take that, Bowlarama! Take that, Convenience Mart! Take that, Nuclear Power Plan--oh, fiddlesticks. \_ Bowlarama! Good times! |
2001/2/9-10 [Politics/Domestic/President/Clinton] UID:20555 Activity:moderate |
2/9 I keep hearing "Bush retreats to his ranch." What is that like, a mansion or somethin'? How come Clinton never retreats to his ranch or penthouse (possibly with interns)? \_ Clinton retreated to the oral^H^H^Hval office \_ That is so incredibly stupid it's making my eyes bleed. \_ Watch a western sometime, cowboy, and then you'll understand. \_ Is this a "Silverado" or a "Josey Wales" kinda retreat? \_ It's a "daddy, what do I do now?" sort of retreat. |
3/15 |