<s>
The	O
island	B-Algorithm
algorithm	I-Algorithm
is	O
an	O
algorithm	O
for	O
performing	O
inference	O
on	O
hidden	O
Markov	O
models	O
,	O
or	O
their	O
generalization	O
,	O
dynamic	O
Bayesian	O
networks	O
.	O
</s>
<s>
The	O
island	B-Algorithm
algorithm	I-Algorithm
is	O
a	O
modification	O
of	O
belief	O
propagation	O
.	O
</s>
<s>
It	O
trades	O
smaller	O
memory	B-General_Concept
usage	I-General_Concept
for	O
longer	O
running	O
time	O
:	O
while	O
belief	O
propagation	O
takes	O
O(n )	O
time	O
and	O
O(n )	O
memory	O
,	O
the	O
island	B-Algorithm
algorithm	I-Algorithm
takes	O
O(n log n )	O
time	O
and	O
O(log n )	O
memory	O
.	O
</s>
