<s>
Direct	B-Algorithm
simulation	I-Algorithm
Monte	I-Algorithm
Carlo	I-Algorithm
(	O
DSMC	O
)	O
method	O
uses	O
probabilistic	O
Monte	B-Algorithm
Carlo	I-Algorithm
simulation	I-Algorithm
to	O
solve	O
the	O
Boltzmann	O
equation	O
for	O
finite	O
Knudsen	O
number	O
fluid	O
flows	O
.	O
</s>
<s>
DSMC	O
is	O
a	O
numerical	O
method	O
for	O
modeling	O
rarefied	O
gas	O
flows	O
,	O
in	O
which	O
the	O
mean	B-Algorithm
free	I-Algorithm
path	I-Algorithm
of	O
a	O
molecule	O
is	O
of	O
the	O
same	O
order	O
(	O
or	O
greater	O
)	O
than	O
a	O
representative	O
physical	O
length	O
scale	O
(	O
i.e.	O
</s>
<s>
Currently	O
,	O
the	O
DSMC	O
method	O
has	O
been	O
applied	O
to	O
the	O
solution	O
of	O
flows	O
ranging	O
from	O
estimation	O
of	O
the	O
Space	O
Shuttle	O
re-entry	O
aerodynamics	O
to	O
the	O
modeling	O
of	O
microelectromechanical	B-Architecture
systems	I-Architecture
(	O
MEMS	B-Architecture
)	O
.	O
</s>
<s>
(	O
e.g.	O
,	O
periodic	B-Algorithm
boundary	I-Algorithm
conditions	I-Algorithm
)	O
.	O
</s>
<s>
Typically	O
the	O
dimension	O
of	O
a	O
cell	O
is	O
no	O
larger	O
than	O
a	O
mean	B-Algorithm
free	I-Algorithm
path	I-Algorithm
.	O
</s>
<s>
Instead	O
,	O
the	O
following	O
rejection	B-Algorithm
sampling	I-Algorithm
scheme	O
can	O
be	O
used	O
to	O
select	O
collision	O
pairs	O
:	O
</s>
<s>
these	O
angles	O
are	O
selected	O
by	O
a	O
Monte	B-Algorithm
Carlo	I-Algorithm
process	O
with	O
distributions	O
given	O
by	O
the	O
collision	O
model	O
.	O
</s>
