<s>
In	O
signal	O
processing	O
,	O
the	O
fast	B-Algorithm
folding	I-Algorithm
algorithm	I-Algorithm
(	O
Staelin	O
,	O
1969	O
)	O
is	O
an	O
efficient	O
algorithm	O
for	O
the	O
detection	O
of	O
approximately-periodic	O
events	O
within	O
time	O
series	O
data	O
.	O
</s>
<s>
The	O
FFA	O
is	O
best	O
known	O
for	O
its	O
use	O
in	O
the	O
detection	O
of	O
pulsars	B-Application
,	O
as	O
popularised	O
by	O
SETI	B-Application
@home	I-Application
and	O
Astropulse	B-Operating_System
.	O
</s>
