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is not Spanish (the input file was Cervante's Don Quijote , also with m=3 ), and

Seule sontagne trait homarcher de la t au onze le quance matices Maississait passepart penaientla ples les au cherche de je Chamain peut accide bien avaien rie se vent puis il nez pande

is not French (the source was Le Tour du Monde en Quatre Vingts Jours , a translation of Jules Verne's Around the World in Eighty Days. )

The input file to the program textsim.m is a M atlab .mat file that is preprocessed to remove excessive line breaks, spaces, and capitalization using textman.m , which is why there is no punctuation in these examples. A large assortment oftext files is available for downloading at the website of Project Gutenberg (at http://promo.net/pg/).

Text, in a variety of languages, retains some of the character of its language with correlationsof 3 to 5 letters (21–35 bits, when coded in ASCII). Thus, messages written in those languagesare not independent, except possibly at lengths greater than this. A result from probability theory suggests that ifthe letters are clustered into blocks that are longer than the correlation, then the blocksmay be (nearly) independent. This is one strategy to pursue when designing codes that seek to optimize performance. "Source Coding" will explore some practical ways to attack this problem, but the next two sections establish a measure ofperformance such that it is possible to know how close to the optimal any given code lies.


This section extends the concept of information from a single symbol to a sequence of symbols.As defined by Shannon, Actually, Hartley was the first to use this as a measure of information in his1928 paper in the Bell Systems Technical Journal called “Transmission of Information.” the information in a symbol is inversely proportional to its probability of occurring.Since messages are composed of sequences of symbols, it is important to be able to talk concretelyabout the average flow of information. This is called the entropy and is formally defined as

H ( x ) = i = 1 N p ( x i ) I ( x i ) = i = 1 N p ( x i ) log 1 p ( x i ) = - i = 1 N p ( x i ) log ( p ( x i ) ) ,

where the symbols are drawn from an alphabet x i , each with probability p ( x i ) . H ( x ) sums the information in each symbol, weighted by the probability of that symbol.Those familiar with probability and random variables will recognize this as an expectation. Entropy Warning: though the word is the same, this is not the sameas the notion of entropy that is familiar from physics since the units here are in bits per symbol whilethe units in physics are energy per degree kelvin. is measured in bits per symbol, and so gives a measure of the average amount of informationtransmitted by the symbols of the source. Sources with different symbol sets and different probabilitieshave different entropies. When the probabilities are known, the definition is easy to apply.

Consider the N = 3 symbol set defined in Example [link] . The entropy is

H ( x ) = 1 2 · 1 + 1 4 · 2 + 1 4 · 2 = 1 . 5 bits/symbol .

Reconsider the fair die of [link] . What is its entropy?

Suppose that the message { x 1 , x 3 , x 2 , x 1 } is received from a source characterized by

Questions & Answers

what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Software receiver design. OpenStax CNX. Aug 13, 2013 Download for free at http://cnx.org/content/col11510/1.3
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