<s>
In	O
artificial	B-Application
intelligence	I-Application
,	O
especially	O
computer	B-Application
vision	I-Application
and	O
artificial	B-Architecture
neural	I-Architecture
networks	I-Architecture
,	O
a	O
hard	B-Algorithm
sigmoid	I-Algorithm
is	O
non-smooth	O
function	O
used	O
in	O
place	O
of	O
a	O
sigmoid	B-Algorithm
function	I-Algorithm
.	O
</s>
<s>
Other	O
examples	O
include	O
the	O
Theano	B-Algorithm
library	O
,	O
which	O
provides	O
two	O
approximations	O
:	O
ultra_fast_sigmoid	O
,	O
which	O
is	O
a	O
multi-part	O
piecewise	O
approximation	O
and	O
hard_sigmoid	O
,	O
which	O
is	O
a	O
3-part	O
piecewise	O
linear	O
approximation	O
(	O
output	O
0	O
,	O
line	O
with	O
slope	O
0.2	O
,	O
output	O
1	O
)	O
.	O
</s>
