<s>
Ecolego	B-Application
is	O
a	O
simulation	B-Application
software	I-Application
tool	O
that	O
is	O
used	O
for	O
creating	O
dynamic	O
models	O
and	O
performing	O
deterministic	O
and	O
probabilistic	O
simulations	O
.	O
</s>
<s>
Ecolego	B-Application
can	O
be	O
applied	O
in	O
a	O
variety	O
of	O
areas	O
,	O
but	O
is	O
mainly	O
used	O
for	O
risk	O
assessment	O
in	O
radioecology	O
,	O
environmental	O
physics	O
and	O
PBPK	O
modeling	O
.	O
</s>
<s>
To	O
facilitate	O
the	O
use	O
of	O
Ecolego	B-Application
in	O
the	O
field	O
of	O
radiology	O
,	O
specialized	O
databases	O
and	O
other	O
add-ons	O
have	O
been	O
developed	O
.	O
</s>
<s>
The	O
software	O
was	O
initially	O
developed	O
as	O
a	O
complementary	O
user	O
interface	O
to	O
create	O
compartmental	O
models	O
in	O
Simulink	B-Application
.	O
</s>
<s>
Simulink	B-Application
had	O
very	O
powerful	O
and	O
fast	O
solvers	O
for	O
ordinary	O
differential	O
equations	O
,	O
but	O
lacked	O
support	O
for	O
running	O
probabilistic	O
simulations	O
and	O
handling	O
of	O
parameter	O
values	O
.	O
</s>
<s>
Also	O
,	O
Simulink	B-Application
is	O
very	O
detailed	O
–	O
every	O
equation	O
is	O
modeled	O
by	O
graphically	O
operator	O
blocks	O
–	O
making	O
modeling	O
time	O
consuming	O
and	O
prone	O
to	O
mistakes	O
.	O
</s>
<s>
By	O
relying	O
on	O
Simulink	B-Application
for	O
simulations	O
,	O
full	O
attention	O
could	O
be	O
given	O
to	O
the	O
development	O
of	O
an	O
advanced	O
user	O
interface	O
.	O
</s>
<s>
As	O
more	O
and	O
more	O
features	O
where	O
added	O
to	O
Ecolego	B-Application
,	O
the	O
need	O
for	O
an	O
integrated	O
simulation	O
engine	O
grew	O
.	O
</s>
<s>
With	O
the	O
release	O
of	O
Ecolego	B-Application
4	O
in	O
2008	O
,	O
a	O
set	O
of	O
state-of-the-art	O
solvers	O
was	O
incorporated	O
and	O
thus	O
removed	O
the	O
dependence	O
of	O
Simulink	B-Application
.	O
</s>
<s>
Today	O
,	O
SSM	O
uses	O
Ecolego	B-Application
for	O
the	O
review	O
of	O
SKB	O
's	O
(	O
the	O
Swedish	O
Nuclear	O
Waste	O
Management	O
Company	O
)	O
license	O
application	O
for	O
the	O
siting	O
and	O
construction	O
of	O
a	O
repository	O
for	O
the	O
final	O
disposal	O
of	O
spent	O
nuclear	O
fuel	O
in	O
Sweden	O
.	O
</s>
<s>
December	O
2003	O
:	O
the	O
first	O
version	O
,	O
Ecolego	B-Application
1.0	O
,	O
was	O
released	O
.	O
</s>
<s>
In	O
this	O
early	O
version	O
,	O
the	O
software	O
was	O
dependent	O
on	O
Matlab/Simulink	O
to	O
perform	O
simulations	O
.	O
</s>
<s>
February	O
2006	O
:	O
Ecolego	B-Application
2.1	O
was	O
released	O
.	O
</s>
<s>
The	O
user	O
interface	O
of	O
Ecolego	B-Application
was	O
completely	O
remade	O
,	O
and	O
now	O
used	O
a	O
tiling	O
window	O
manager	O
to	O
improve	O
model	O
transparency	O
.	O
</s>
<s>
2007	O
:	O
Ecolego	B-Application
3	O
was	O
released	O
.	O
</s>
<s>
Ecolego	B-Application
now	O
featured	O
a	O
crude	O
integrated	O
calculation	O
engine	O
,	O
reducing	O
the	O
dependence	O
on	O
Matlab/Simulink	O
.	O
</s>
<s>
The	O
support	O
for	O
probabilistic	B-General_Concept
analysis	I-General_Concept
was	O
greatly	O
improved	O
.	O
</s>
<s>
2008	O
:	O
Ecolego	B-Application
4	O
was	O
released	O
.	O
</s>
<s>
Ecolego	B-Application
4	O
now	O
incorporated	O
state-of-the-art	O
solvers	O
for	O
ordinary	O
differential	O
equations	O
,	O
making	O
Matlab/Simulink	O
redundant	O
.	O
</s>
<s>
Fall	O
of	O
2009	O
:	O
the	O
current	O
version	O
of	O
Ecolego	B-Application
,	O
Ecolego	B-Application
5	O
,	O
was	O
released	O
.	O
</s>
<s>
Ecolego	B-Application
5	O
added	O
many	O
features	O
,	O
such	O
as	O
unit	O
checking	O
,	O
sub-version	O
support	O
and	O
a	O
model	O
component	O
library	O
.	O
</s>
<s>
The	O
initial	O
idea	O
of	O
Ecolego	B-Application
was	O
to	O
facilitate	O
creation	O
of	O
large	O
and	O
complex	O
models	O
and	O
to	O
be	O
able	O
to	O
solve	O
difficult	O
numerical	O
problems	O
.	O
</s>
<s>
With	O
the	O
purpose	O
to	O
make	O
complicated	O
models	O
with	O
many	O
interconnections	O
easier	O
to	O
overview	O
,	O
the	O
models	O
in	O
Ecolego	B-Application
are	O
represented	O
with	O
the	O
help	O
of	O
interaction	O
matrices	O
instead	O
of	O
the	O
traditional	O
flow	O
diagrams	O
.	O
</s>
<s>
Objects	O
can	O
be	O
assigned	O
comments	O
,	O
images	O
,	O
units	O
,	O
and	O
hyper	O
links	O
to	O
other	O
documents	O
or	O
Ecolego	B-Application
objects	O
.	O
</s>
<s>
Ecolego	B-Application
can	O
also	O
create	O
reports	O
that	O
contain	O
everything	O
from	O
interaction	O
matrices	O
,	O
to	O
parameter	O
values	O
,	O
equations	O
,	O
decay	O
chains	O
,	O
plots	O
and	O
tables	O
.	O
</s>
<s>
In	O
order	O
to	O
increase	O
the	O
flexibility	O
for	O
the	O
user	O
,	O
Ecolego	B-Application
has	O
no	O
restrictions	O
on	O
the	O
order	O
of	O
creation	O
–	O
for	O
instance	O
,	O
a	O
parameter	O
can	O
be	O
used	O
in	O
equations	O
before	O
it	O
is	O
defined	O
.	O
</s>
<s>
The	O
library	O
can	O
be	O
exported	O
,	O
so	O
that	O
users	O
with	O
Ecolego	B-Application
Player	O
can	O
use	O
it	O
to	O
create	O
models	O
without	O
the	O
need	O
of	O
an	O
Ecolego	B-Application
license	O
.	O
</s>
<s>
Several	O
other	O
features	O
in	O
Ecolego	B-Application
promote	O
quality	O
assurance	O
:	O
</s>
<s>
The	O
typical	O
Ecolego	B-Application
model	O
is	O
a	O
compartmental	O
model	O
which	O
requires	O
a	O
solver	O
of	O
differential	O
equations	O
.	O
</s>
<s>
Some	O
are	O
optimized	O
for	O
stiff	B-Algorithm
and	O
numerically	O
difficult	O
models	O
,	O
others	O
for	O
trivial	O
models	O
.	O
</s>
<s>
With	O
an	O
extensive	O
list	O
of	O
probability	O
density	O
functions	O
,	O
together	O
with	O
Monte	B-Application
Carlo	I-Application
and	O
Latin	O
hypercube	O
sampling	O
and	O
parameter	O
correlation	O
settings	O
,	O
Ecolego	B-Application
holds	O
all	O
the	O
required	O
tools	O
to	O
perform	O
advanced	O
probabilistic	B-General_Concept
analysis	I-General_Concept
.	O
</s>
<s>
Ecolego	B-Application
Player	O
is	O
a	O
free	O
software	O
tool	O
that	O
makes	O
it	O
possible	O
to	O
perform	O
calculations	O
with	O
Ecolego	B-Application
models	O
without	O
having	O
access	O
to	O
Ecolego	B-Application
.	O
</s>
<s>
The	O
software	O
features	O
the	O
same	O
functionality	O
as	O
Ecolego	B-Application
,	O
with	O
the	O
exception	O
that	O
the	O
integral	O
structure	O
of	O
the	O
model	O
cannot	O
be	O
changed	O
.	O
</s>
<s>
However	O
,	O
with	O
a	O
module	O
library	O
created	O
in	O
Ecolego	B-Application
,	O
the	O
user	O
can	O
assemble	O
models	O
by	O
combining	O
components	O
from	O
the	O
library	O
.	O
</s>
<s>
Although	O
it	O
is	O
possible	O
to	O
perform	O
sensitivity	O
analysis	O
in	O
Ecolego	B-Application
,	O
the	O
Sensitivity	O
Analysis	O
Toolbox	O
is	O
an	O
optional	O
module	O
which	O
gives	O
a	O
larger	O
set	O
of	O
tools	O
for	O
this	O
approach	O
.	O
</s>
<s>
The	O
supported	O
sampling	O
techniques	O
are	O
:	O
Monte	B-Application
carlo	I-Application
,	O
Latin	O
Hypercube	O
and	O
Quasi-random	O
LPt	O
.	O
</s>
