Domain: bu.edu
Stories and comments across the archive that link to bu.edu.
Comments · 256
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Re:sqlplus--how to get good cmd history, etc.
If you want to have an improved SQL*PLUS command-line capability, with command history, file-completion, etc. try running SQL*PLUS from a shell within emacs.
No, really--it's quite simple, actually. You start up emacs, start a unix shell (by typing: M-x shell ) and from that shell run SQL*PLUS as you normally do.
[N.B. For emacs newbies: the "M" stands for "Meta" and usually maps to the ALT key, the "C" stands for the CTRL key--each of these is pressed together with a second key to do a command. So "M-x" means press the ALT and x keys together. Oh, and RET is the RETurn key]
Emacs has a bunch of commands that let will let you cycle backwards through previous commands (M-p), search backwards for a command with a given string in it(the usual backwards search, C-r and you can do regular expression searches the normal way too), edit the command, copy a command to the prompt without sending it, so you can edit it (C-c RET), etc. And you can get filename completion with the TAB key.
Read all about it here on this very helpful page put together by Bob Rogers to help people who used emacs for just about everything during the August '99 bootcamp that Ars Digita (i.e. Philip Greenspun and co.) ran:
http://bmerc-www.bu.edu/needle-doc/emacs/ .
If you know already know emacs, just click on the "running a shell mode in emacs" link in the table of contents (or click here). If you don't know emacs well, just start reading from the top of the page and then go down to the shell mode stuff. Either way, you might find his emacs cheat sheet useful too and some of the other links that he has.
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DC
P.S. For the complete text (and photos) of Philip Greenspun's database-backed web-site book, which describes the philosophy and workings of the Ars Digita ACS toolkit (open-source), among other things, click here For info on the Ars Digita bootcamps, based on this book and the ACS toolkit it describes, click here. -
Re:Hmmm.Polaroid OEM also sells the sonar rangefinder modules because they have a number of uses. See the Robotics Sonar FAQ. I also found a page which describes robotic sonar uses, and another ultrasonic robotics page.
There are also other devices which could be used for position sensing, such as wireless joysticks or electronic whiteboard devices.
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Zipf's lawPopularities of documents (based on URLs) have been known for years to follow a "Zipf-like" distribution (loosely stated, popular pages are REALLY popular, unpopular pages are REALLY unpopular; formally, the probability of retrieving a particular page is inversely proportional to its rank), and it has been generally agreed that sites (for whatever definition of "site" you want to choose - is my.yahoo.com a different site than www.yahoo.com?) follow a similar distribution.
Some recent studies (see CS-TR-98-016 at www.cs.bu.edu/techreports/) have indicated that, in general, the "slope" or "skew" for documents is actually decreasing, meaning the more popular documents seem to be (from a network perspective) "less more popular"
;-) than they used to be. This makes sense if you assume that people are using bigger browser caches (fewer repeated retrievals of the same URI are needed), and keeping in mind that sites are moving session state information that used to be embedded in the URI into cookies (thus reducing the number of "tail" documents that would have been hit once and only once).The problem with popularity profiles is that they are generally not reflective of how much content is being disseminated - if I want my site to attract twice as many "hits", I just have to embed twice as many images in each of my web pages, then tell everyone they're "necessary for proper layout" so people don't get suspicious.
In summary, I'm not at all surprised by these findings, but I doubt the study would stand up to rigorous peer review; I would be curious to see the actual charts-n-graphs, which are _FAR_ more instructive than just "top 50, top 100, top 10%" numbers. Unless one of the distribution is super-skewed (Zipf exponent is less than -1.0), this is probably just part of the normal osciallation of popularity and centralization/decentralization that we've seen since the dawn of knowledge. (How's that for putting a grandeur spin on it?)
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Re:Get the facts right, losers
The problem is, it still doesn't make much difference. Claiming that any abnormalities were the cause of Einstein's intelligence is way off the mark; we just don't know enough about brains to say that. We aren't even really sure how common "abnormal" brains (and other body parts) are, because the vast majority of people are not that closely examined after death. Furthermore, some "abnormalities" have no noticeable effects ante mortem - I recall the (apocryphal?) story of a man who was autopsied and found to have a left hemisphere only the size of a walnut, but who had shown no unusual mental characteristics one way or the other during his life. I majored in Anthropology at Boston University, and my advisor was Doctor Terrance Deacon, so I'd like to think I have some idea what I'm talking about.
;^) -
Re:Get the facts right, losers
The problem is, it still doesn't make much difference. Claiming that any abnormalities were the cause of Einstein's intelligence is way off the mark; we just don't know enough about brains to say that. We aren't even really sure how common "abnormal" brains (and other body parts) are, because the vast majority of people are not that closely examined after death. Furthermore, some "abnormalities" have no noticeable effects ante mortem - I recall the (apocryphal?) story of a man who was autopsied and found to have a left hemisphere only the size of a walnut, but who had shown no unusual mental characteristics one way or the other during his life. I majored in Anthropology at Boston University, and my advisor was Doctor Terrance Deacon, so I'd like to think I have some idea what I'm talking about.
;^) -
Re:Get the facts right, losers
The problem is, it still doesn't make much difference. Claiming that any abnormalities were the cause of Einstein's intelligence is way off the mark; we just don't know enough about brains to say that. We aren't even really sure how common "abnormal" brains (and other body parts) are, because the vast majority of people are not that closely examined after death. Furthermore, some "abnormalities" have no noticeable effects ante mortem - I recall the (apocryphal?) story of a man who was autopsied and found to have a left hemisphere only the size of a walnut, but who had shown no unusual mental characteristics one way or the other during his life. I majored in Anthropology at Boston University, and my advisor was Doctor Terrance Deacon, so I'd like to think I have some idea what I'm talking about.
;^)