<s>
In	O
1936	O
,	O
Shannon	O
began	O
his	O
graduate	O
studies	O
in	O
electrical	O
engineering	O
at	O
MIT	O
,	O
where	O
he	O
worked	O
on	O
Vannevar	O
Bush	O
's	O
differential	B-Device
analyzer	I-Device
,	O
an	O
early	O
analog	O
computer	O
.	O
</s>
<s>
Shannon	O
then	O
joined	O
Bell	O
Labs	O
to	O
work	O
on	O
fire-control	B-Application
systems	I-Application
and	O
cryptography	O
during	O
World	O
War	O
II	O
,	O
under	O
a	O
contract	O
with	O
section	O
D-2	O
(	O
Control	O
Systems	O
section	O
)	O
of	O
the	O
National	O
Defense	O
Research	O
Committee	O
(	O
NDRC	O
)	O
.	O
</s>
<s>
Turing	O
had	O
been	O
posted	O
to	O
Washington	O
to	O
share	O
with	O
the	O
U.S.	O
Navy	O
's	O
cryptanalytic	O
service	O
the	O
methods	O
used	O
by	O
the	O
British	O
Government	O
Code	O
and	O
Cypher	O
School	O
at	O
Bletchley	O
Park	O
to	O
break	O
the	O
ciphers	O
used	O
by	O
the	O
Kriegsmarine	O
U-boats	B-Operating_System
in	O
the	O
north	O
Atlantic	O
Ocean	O
.	O
</s>
<s>
Inside	O
the	O
volume	O
on	O
fire	O
control	O
,	O
a	O
special	O
essay	O
titled	O
Data	B-General_Concept
Smoothing	O
and	O
Prediction	O
in	O
Fire-Control	B-Application
Systems	I-Application
,	O
coauthored	O
by	O
Shannon	O
,	O
Ralph	O
Beebe	O
Blackman	O
,	O
and	O
Hendrik	O
Wade	O
Bode	O
,	O
formally	O
treated	O
the	O
problem	O
of	O
smoothing	O
the	O
data	B-General_Concept
in	O
fire-control	B-Application
by	O
analogy	O
with	O
"	O
the	O
problem	O
of	O
separating	O
a	O
signal	O
from	O
interfering	O
noise	O
in	O
communications	O
systems.	O
"	O
</s>
<s>
In	O
other	O
words	O
,	O
it	O
modeled	O
the	O
problem	O
in	O
terms	O
of	O
data	B-General_Concept
and	O
signal	O
processing	O
and	O
thus	O
heralded	O
the	O
coming	O
of	O
the	O
Information	O
Age	O
.	O
</s>
<s>
While	O
he	O
was	O
at	O
Bell	O
Labs	O
,	O
Shannon	O
proved	O
that	O
the	O
cryptographic	O
one-time	B-Algorithm
pad	I-Algorithm
is	O
unbreakable	O
in	O
his	O
classified	O
research	O
that	O
was	O
later	O
published	O
1949	O
.	O
</s>
<s>
The	O
same	O
article	O
also	O
proved	O
that	O
any	O
unbreakable	O
system	O
must	O
have	O
essentially	O
the	O
same	O
characteristics	O
as	O
the	O
one-time	B-Algorithm
pad	I-Algorithm
:	O
the	O
key	O
must	O
be	O
truly	O
random	O
,	O
as	O
large	O
as	O
the	O
plaintext	O
,	O
never	O
reused	O
in	O
whole	O
or	O
part	O
,	O
and	O
kept	O
secret	O
.	O
</s>
<s>
Information	O
theory	O
's	O
fundamental	O
contribution	O
to	O
natural	B-Language
language	I-Language
processing	I-Language
and	O
computational	O
linguistics	O
was	O
further	O
established	O
in	O
1951	O
,	O
in	O
his	O
article	O
"	O
Prediction	O
and	O
Entropy	O
of	O
Printed	O
English	O
"	O
,	O
showing	O
upper	O
and	O
lower	O
bounds	O
of	O
entropy	O
on	O
the	O
statistics	O
of	O
English	O
–	O
giving	O
a	O
statistical	O
foundation	O
to	O
language	O
analysis	O
.	O
</s>
<s>
Another	O
notable	O
paper	O
published	O
in	O
1949	O
is	O
"	O
Communication	O
Theory	O
of	O
Secrecy	O
Systems	O
"	O
,	O
a	O
declassified	O
version	O
of	O
his	O
wartime	O
work	O
on	O
the	O
mathematical	O
theory	O
of	O
cryptography	O
,	O
in	O
which	O
he	O
proved	O
that	O
all	O
theoretically	O
unbreakable	O
ciphers	O
must	O
have	O
the	O
same	O
requirements	O
as	O
the	O
one-time	B-Algorithm
pad	I-Algorithm
.	O
</s>
<s>
He	O
is	O
also	O
credited	O
with	O
the	O
introduction	O
of	O
sampling	B-Algorithm
theory	O
,	O
which	O
is	O
concerned	O
with	O
representing	O
a	O
continuous-time	O
signal	O
from	O
a	O
(	O
uniform	O
)	O
discrete	O
set	O
of	O
samples	O
.	O
</s>
<s>
Outside	O
of	O
Shannon	O
's	O
academic	O
pursuits	O
,	O
he	O
was	O
interested	O
in	O
juggling	O
,	O
unicycling	O
,	O
and	O
chess	B-Application
.	O
</s>
<s>
He	O
also	O
invented	O
many	O
devices	O
,	O
including	O
a	O
Roman	O
numeral	O
computer	O
called	O
THROBAC	B-Device
,	O
and	O
juggling	O
machines	O
.	O
</s>
<s>
He	O
is	O
also	O
considered	O
the	O
co-inventor	O
of	O
the	O
first	O
wearable	B-Operating_System
computer	I-Operating_System
along	O
with	O
Edward	O
O	O
.	O
Thorp	O
.	O
</s>
<s>
According	O
to	O
Neil	O
Sloane	O
,	O
an	O
AT&T	O
Fellow	O
who	O
co-edited	O
Shannon	O
's	O
large	O
collection	O
of	O
papers	O
in	O
1993	O
,	O
the	O
perspective	O
introduced	O
by	O
Shannon	O
's	O
communication	O
theory	O
(	O
now	O
called	O
information	O
theory	O
)	O
is	O
the	O
foundation	O
of	O
the	O
digital	O
revolution	O
,	O
and	O
every	O
device	O
containing	O
a	O
microprocessor	B-Architecture
or	O
microcontroller	B-Architecture
is	O
a	O
conceptual	O
descendant	O
of	O
Shannon	O
's	O
publication	O
in	O
1948	O
:	O
"	O
He	O
's	O
one	O
of	O
the	O
great	O
men	O
of	O
the	O
century	O
.	O
</s>
<s>
"	O
Theseus	O
"	O
,	O
created	O
in	O
1950	O
,	O
was	O
a	O
mechanical	O
mouse	O
controlled	O
by	O
an	O
electromechanical	O
relay	O
circuit	O
that	O
enabled	O
it	O
to	O
move	O
around	O
a	O
labyrinth	B-Application
of	O
25	O
squares	O
.	O
</s>
<s>
The	O
maze	B-Application
configuration	O
was	O
flexible	O
and	O
it	O
could	O
be	O
modified	O
arbitrarily	O
by	O
rearranging	O
movable	O
partitions	O
.	O
</s>
<s>
Having	O
travelled	O
through	O
the	O
maze	B-Application
,	O
the	O
mouse	O
could	O
then	O
be	O
placed	O
anywhere	O
it	O
had	O
been	O
before	O
,	O
and	O
because	O
of	O
its	O
prior	O
experience	O
it	O
could	O
go	O
directly	O
to	O
the	O
target	O
.	O
</s>
<s>
In	O
1949	O
Shannon	O
completed	O
a	O
paper	O
(	O
published	O
in	O
March	O
1950	O
)	O
which	O
estimates	O
the	O
game-tree	O
complexity	O
of	O
chess	B-Application
,	O
which	O
is	O
approximately	O
10120	O
.	O
</s>
<s>
The	O
number	O
is	O
often	O
cited	O
as	O
one	O
of	O
the	O
barriers	O
to	O
solving	O
the	O
game	O
of	O
chess	B-Application
using	O
an	O
exhaustive	O
analysis	O
(	O
i.e.	O
</s>
<s>
brute	B-Algorithm
force	I-Algorithm
analysis	I-Algorithm
)	O
.	O
</s>
<s>
On	O
March	O
9	O
,	O
1949	O
,	O
Shannon	O
presented	O
a	O
paper	O
called	O
"	O
Programming	O
a	O
Computer	O
for	O
playing	O
Chess	B-Application
"	O
.	O
</s>
<s>
He	O
described	O
how	O
to	O
program	O
a	O
computer	O
to	O
play	O
chess	B-Application
based	O
on	O
position	O
scoring	O
and	O
move	O
selection	O
.	O
</s>
<s>
He	O
proposed	O
basic	O
strategies	O
for	O
restricting	O
the	O
number	O
of	O
possibilities	O
to	O
be	O
considered	O
in	O
a	O
game	O
of	O
chess	B-Application
.	O
</s>
<s>
In	O
March	O
1950	O
it	O
was	O
published	O
in	O
Philosophical	O
Magazine	O
,	O
and	O
is	O
considered	O
one	O
of	O
the	O
first	O
articles	O
published	O
on	O
the	O
topic	O
of	O
programming	O
a	O
computer	O
for	O
playing	O
chess	B-Application
,	O
and	O
using	O
a	O
computer	O
to	O
solve	O
the	O
game	O
.	O
</s>
<s>
His	O
process	O
for	O
having	O
the	O
computer	O
decide	O
on	O
which	O
move	O
to	O
make	O
was	O
a	O
minimax	B-Algorithm
procedure	O
,	O
based	O
on	O
an	O
evaluation	B-General_Concept
function	I-General_Concept
of	O
a	O
given	O
chess	B-Application
position	O
.	O
</s>
<s>
Shannon	O
gave	O
a	O
rough	O
example	O
of	O
an	O
evaluation	B-General_Concept
function	I-General_Concept
in	O
which	O
the	O
value	O
of	O
the	O
black	O
position	O
was	O
subtracted	O
from	O
that	O
of	O
the	O
white	O
position	O
.	O
</s>
<s>
Material	O
was	O
counted	O
according	O
to	O
the	O
usual	O
chess	B-Application
piece	O
relative	O
value	O
(	O
1	O
point	O
for	O
a	O
pawn	O
,	O
3	O
points	O
for	O
a	O
knight	O
or	O
bishop	O
,	O
5	O
points	O
for	O
a	O
rook	O
,	O
and	O
9	O
points	O
for	O
a	O
queen	O
)	O
.	O
</s>
