full-disclosure - Re: Does this exist ?

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Date: Thu, 12 Jul 2007 21:04:50 +0200
From: Harry Behrens <harry@...rens.com>
To: Dan Becker <list@...nixsolutions.com>
Cc: full-disclosure <full-disclosure@...ts.grok.org.uk>,
	Valdis.Kletnieks@...edu
Subject: Re: Does this exist ?

> Thank you for the reply. This is not helping my headache.
>
> There simply has to be a way to represent a larger value than you  
> transmit when you transmit.
>
>   
by consulting Shannon you will find:
only if you can index the value against a relatively small set of 
possible values.
The possible values need to exist as reference sets, i.e. you are 
trading storage space for transmission bandwidth.
This is important: the reference sets need to be shared (as data or - 
probably impossible - as a generative function) and pre-existing to the 
moment of "encoding"
In that case using the index is entropically more efficient than 
transmitting the actual data.

The most drastic example is sending an index to one of ten possible 
videos, you have truly represented a much larger value (a number several 
100 Million digits long: the video data) with < 4 bits.
Or how our professor in networking told us 1980 (still valid today I 
believe):
If you pack a Being 747 full of CDs (now DVDs) and send it over to NY, 
that yields a higher "bandwidth" than any network connectivity.

All of this is merely academic anyway, i.e. no immediate practical use.

Regards,

    Harry

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