<s>
Piranha	B-Operating_System
is	O
a	O
text	B-Algorithm
mining	I-Algorithm
system	O
developed	O
for	O
the	O
United	O
States	O
Department	O
of	O
Energy	O
(	O
DOE	O
)	O
by	O
Oak	O
Ridge	O
National	O
Laboratory	O
(	O
ORNL	O
)	O
.	O
</s>
<s>
Piranha	B-Operating_System
uses	O
the	O
term	O
frequency/inverse	O
corpus	O
frequency	O
term	O
weighting	O
method	O
which	O
provides	O
strong	O
parallel	O
processing	O
of	O
textual	O
information	O
,	O
thus	O
the	O
ability	O
to	O
analyze	O
very	O
large	O
document	O
sets	O
.	O
</s>
<s>
Piranha	B-Operating_System
has	O
six	O
main	O
strengths	O
:	O
</s>
