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Books & Articles I wrote.

Monday, May 01, 2006


Canonicalize v Normalize

Canonicalize usually means "Transform to canonical form,"
while normalize usually means "Transform to normal form."

Canonical form is a unique form of whatever it is you're looking at allowing
comparing for equality of two items from the space by comparing their
canonical forms for identity. It must be true that every element of the
domain has a canonical form and that the canonicalization function is
idempotent (it doesn't change something already in canonical form).

So when you have a*(b+c), somebody has to decide whether the canonical form
is a*(b+c) or a*b + a*c. The transformation to canonical form of all
expressions involving multiplication and addition is then straightforward
(you have to remember to sort the terms of a sum or product in some
canonical order). Sometimes transforming to canonical form requires a lot
of knowledge; for example, the canonical form of exp(i*pi)+1 is probably
going to be 0 given any reasonable definition of canonical form. In certain
domains, reduction to canonical form is undecidable (would correspond to
being able solve certain hard equations).

Normal form is similar to canonical form, except that it is sometimes not
unique. (For example, in databases, people talk about 1st, 2nd, 3rd and 4th
normal forms for a table structure.)
Probably, when there is just one normal form in the domain, conflating
canonical with normal is relatively harmless.

source : http://lists.xml.org/archives/xml-dev/200307/msg00883.html

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Monday Clicks

btw - why doesn't blogger save your IP address for a period of time (mine hardly changes) and associate it with your account so you don't have this captcha every time?

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Where for Google?

Google has done some amazing things in the last few years and increasingly have tried to diversify its technology portfolio away from pure search into, i guess extended search - that is applying their technology in new areas (maps, books, blogs and so on).

The problem is that the more they diversify, the more they start to overlap with many of the companies using their technology. The latest (btw - see the cool LivePlasma navigation technology there - reminds me of thebrain.com) is Amazon who have now switched to Microsoft getting results from Microsoft Live and not Google.

This has nothing to do with the search engine. It is to do with Google looking to broker online book sales. Microsoft have stuck fairly closely to technology, perhaps portals being the fartherst they have ventured from that. Sure they have a book portal and an intention to launch MSN Book Search, but they've been careful not to stand on anyones toes.

The point is not that Google will rise or die on any one deal, but we're now starting to see their lead in search start to waver a little and a deal like this may have a small, motonically increasing ripple that one day may just tip. It really depends on where Google go next, how they are viewed by the companies using their technology and whether anyone sees them as a threat - they have stayed under the radar in this respect - until now.

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Small World - An Edge Case

This sounds absolutely bloddy ridiculus, but I've lost the Small World book i have been reading. I am about 20 pages from the end of it, but it has disappeared - for over a week now.

I've asked a friend (my wife) and a friend of a friend (my wife's son, who is well, my son too, but go with it) - no joy.

I don't know that i've ever got near to the end of a book and had such a counter lesson in what i have read.

I'll keep looking as it MUST be somwhere - which brings me to the Quantum Physics book i have...

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Eye Spy

This is a good test to determine whether you can tell Spyware when you see it.

I got 7 out of 8 and the one that got me was bearshare.com - no idea why as i was 50/50 on it.

It's not easy to tell sometimes - give it a try and see how you do.

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