<s>
Modelica	B-Application
is	O
an	O
object-oriented	B-Language
,	O
declarative	B-Language
,	O
multi-domain	O
modeling	B-Language
language	I-Language
for	O
component-oriented	B-Architecture
modeling	O
of	O
complex	O
systems	O
,	O
e.g.	O
,	O
systems	O
containing	O
mechanical	O
,	O
electrical	O
,	O
electronic	O
,	O
hydraulic	O
,	O
thermal	O
,	O
control	O
,	O
electric	O
power	O
or	O
process-oriented	O
subcomponents	O
.	O
</s>
<s>
is	O
developed	O
by	O
the	O
non-profit	O
Modelica	B-Application
Association	O
.	O
</s>
<s>
The	O
Modelica	B-Application
Association	O
also	O
develops	O
the	O
free	O
Modelica	B-Application
Standard	O
Library	O
that	O
contains	O
about	O
1400	O
generic	O
model	O
components	O
and	O
1200	O
functions	O
in	O
various	O
domains	O
,	O
as	O
of	O
version	O
4.0.0	O
.	O
</s>
<s>
While	O
Modelica	B-Application
resembles	O
object-oriented	B-Language
programming	I-Language
languages	I-Language
,	O
such	O
as	O
C++	B-Language
or	O
Java	B-Language
,	O
it	O
differs	O
in	O
two	O
important	O
respects	O
.	O
</s>
<s>
First	O
,	O
Modelica	B-Application
is	O
a	O
modeling	B-Language
language	I-Language
rather	O
than	O
a	O
conventional	O
programming	O
language	O
.	O
</s>
<s>
Modelica	B-Application
classes	O
are	O
not	O
compiled	O
in	O
the	O
usual	O
sense	O
,	O
but	O
they	O
are	O
translated	O
into	O
objects	O
which	O
are	O
then	O
exercised	O
by	O
a	O
simulation	O
engine	O
.	O
</s>
<s>
In	O
Modelica	B-Application
terms	O
,	O
equations	O
have	O
no	O
pre-defined	O
causality	O
.	O
</s>
<s>
The	O
Modelica	B-Application
design	O
effort	O
was	O
initiated	O
in	O
September	O
1996	O
by	O
Hilding	O
Elmqvist	O
.	O
</s>
<s>
PhD	O
thesis	O
of	O
Hilding	O
Elmqvist	O
and	O
on	O
the	O
experience	O
with	O
the	O
modeling	B-Language
languages	I-Language
Allan	O
,	O
</s>
<s>
Hilding	O
Elmqvist	O
is	O
the	O
key	O
architect	O
of	O
Modelica	B-Application
,	O
but	O
many	O
other	O
people	O
have	O
contributed	O
as	O
well	O
(	O
see	O
appendix	O
E	O
in	O
the	O
Modelica	B-Application
specification	O
)	O
.	O
</s>
<s>
In	O
September	O
1997	O
,	O
version	O
1.0	O
of	O
the	O
Modelica	B-Application
specification	O
was	O
released	O
which	O
was	O
the	O
basis	O
for	O
a	O
prototype	O
implementation	O
within	O
the	O
commercial	O
Dymola	B-Application
software	O
system	O
.	O
</s>
<s>
In	O
year	O
2000	O
,	O
the	O
non-profit	O
Modelica	B-Application
Association	O
was	O
formed	O
to	O
manage	O
the	O
continually	O
evolving	O
Modelica	B-Application
language	O
and	O
the	O
development	O
of	O
the	O
free	O
Modelica	B-Application
Standard	O
Library	O
.	O
</s>
<s>
In	O
the	O
same	O
year	O
,	O
the	O
usage	O
of	O
Modelica	B-Application
in	O
industrial	O
applications	O
started	O
.	O
</s>
<s>
This	O
table	O
presents	O
the	O
timeline	O
of	O
the	O
Modelica	B-Application
specification	O
history	O
:	O
</s>
<s>
mechanical	O
systems	O
,	O
enhanced	O
redeclaration	O
of	O
submodels	O
,	O
array	O
and	O
array	O
indices	O
of	O
enumerations2.22005	O
,	O
FebruaryExpandable	O
connector	O
to	O
model	O
signal	O
buses	O
,	O
conditional	O
component	O
declarations	O
,	O
arrays	O
with	O
dynamic	O
size	O
changes	O
in	O
functions3.02007	O
,	O
SeptemberClean-up	O
version	O
:	O
specification	O
newly	O
written	O
,	O
type	O
system	O
and	O
graphical	O
appearance	O
refined	O
,	O
language	O
flaws	O
fixed	O
,	O
balanced	O
model	O
concept	O
to	O
detect	O
model	O
errors	O
in	O
a	O
much	O
better	O
way3.12009	O
,	O
MayStream	O
connector	O
to	O
handle	O
bi-directional	O
flow	O
of	O
fluid	O
,	O
operator	O
overloading	O
,	O
mapping	O
model	O
parts	O
to	O
execution	O
environments	O
(	O
for	O
use	O
in	O
embedded	B-Architecture
systems	I-Architecture
)	O
3.22010	O
,	O
MarchImproved	O
initialization	O
with	O
homotopy	O
method	O
,	O
functions	O
as	O
formal	O
inputs	O
to	O
functions	O
,	O
Unicode	O
support	O
,	O
access	O
control	O
to	O
protect	O
IP	O
,	O
improved	O
support	O
of	O
object	O
libraries3.32012	O
,	O
MayAdded	O
language	O
elements	O
to	O
describe	O
periodic	O
and	O
non-periodic	O
synchronous	O
controllers	O
based	O
on	O
clocked	O
equations	O
,	O
as	O
well	O
as	O
synchronous	O
state	O
machines.3.42017	O
,	O
AprilAutomatic	O
conversion	O
of	O
models	O
.	O
</s>
<s>
Commercial	O
front-ends	B-Architecture
for	O
Modelica	B-Application
include	O
AMESim	B-Application
from	O
the	O
French	O
company	O
Imagine	O
SA	O
(	O
now	O
part	O
of	O
Siemens	O
Digital	O
Industries	O
Software	O
)	O
,	O
Dymola	B-Application
from	O
the	O
Swedish	O
company	O
Dynasim	B-Application
AB	O
(	O
now	O
part	O
of	O
Dassault	O
Systemes	O
)	O
,	O
Wolfram	B-Application
SystemModeler	I-Application
(	O
formerly	O
MathModelica	B-Application
)	O
from	O
the	O
Swedish	O
company	O
Wolfram	O
MathCore	O
AB	O
(	O
now	O
part	O
of	O
Wolfram	B-Application
Research	I-Application
)	O
,	O
SimulationX	B-Application
from	O
the	O
German	O
company	O
ESI	B-Application
ITI	I-Application
GmbH	I-Application
,	O
MapleSim	B-Application
from	O
the	O
Canadian	O
company	O
Maplesoft	O
,	O
</s>
<s>
from	O
Dassault	O
Systemes	O
(	O
CATIA	B-Algorithm
is	O
one	O
of	O
the	O
major	O
CAD	B-Application
systems	O
)	O
.	O
</s>
<s>
Openmodelica	B-Application
is	O
an	O
open-source	O
Modelica-based	O
modeling	O
and	O
simulation	O
environment	O
intended	O
for	O
industrial	O
and	O
academic	O
usage	O
.	O
</s>
<s>
Its	O
long-term	O
development	O
is	O
supported	O
by	O
a	O
non-profit	O
organization	O
–	O
the	O
Open	O
Source	O
Modelica	B-Application
Consortium	O
(	O
OSMC	O
)	O
.	O
</s>
<s>
The	O
goal	O
with	O
the	O
OpenModelica	B-Application
effort	O
is	O
to	O
create	O
a	O
comprehensive	O
Open	O
Source	O
Modelica	B-Application
modeling	O
,	O
compilation	O
and	O
simulation	O
environment	O
based	O
on	O
free	O
software	O
distributed	O
in	O
binary	O
and	O
source	O
code	O
form	O
for	O
research	O
,	O
teaching	O
,	O
and	O
industrial	O
usage	O
.	O
</s>
<s>
The	O
free	O
simulation	O
environment	O
Scicos	B-Language
uses	O
a	O
subset	O
of	O
Modelica	B-Application
for	O
component	O
modeling	O
.	O
</s>
<s>
Support	O
for	O
a	O
larger	O
part	O
of	O
the	O
Modelica	B-Application
language	O
is	O
currently	O
under	O
development	O
.	O
</s>
<s>
Nevertheless	O
,	O
there	O
is	O
still	O
some	O
incompatibility	O
and	O
diverging	O
interpretation	O
between	O
all	O
the	O
different	O
tools	O
concerning	O
the	O
Modelica	B-Application
language	O
.	O
</s>
<s>
The	O
main	O
application	O
area	O
of	O
Modelica	B-Application
is	O
the	O
modeling	O
of	O
physical	O
systems	O
.	O
</s>
<s>
Modelica	B-Application
has	O
the	O
four	O
built-in	O
types	O
Real	O
,	O
Integer	O
,	O
Boolean	O
,	O
String	O
.	O
</s>
<s>
A	O
basic	O
model	O
component	O
is	O
defined	O
by	O
a	O
model	O
and	O
contains	O
equations	O
that	O
describe	O
the	O
relationship	O
between	O
the	O
connector	O
variables	O
in	O
a	O
declarative	B-Language
form	O
(	O
i.e.	O
,	O
without	O
specifying	O
the	O
calculation	O
order	O
)	O
:	O
</s>
<s>
In	O
Modelica	B-Application
,	O
this	O
is	O
achieved	O
by	O
requiring	O
so	O
called	O
balanced	O
models	O
.	O
</s>
<s>
Another	O
example	O
,	O
containing	O
both	O
input	O
connectors	O
and	O
physical	O
connectors	O
is	O
the	O
following	O
component	O
from	O
Modelica	B-Application
Standard	O
Library	O
:	O
</s>
<s>
A	O
basic	O
set	O
of	O
graphical	O
annotations	O
is	O
standardized	O
to	O
ensure	O
that	O
the	O
graphical	O
appearance	O
and	O
layout	O
of	O
models	O
in	O
different	O
Modelica	B-Application
tools	O
is	O
the	O
same	O
.	O
</s>
<s>
Modelica	B-Application
is	O
designed	O
to	O
be	O
domain	O
neutral	O
and	O
,	O
as	O
a	O
result	O
,	O
is	O
used	O
in	O
a	O
wide	O
variety	O
of	O
applications	O
,	O
such	O
as	O
fluid	O
systems	O
(	O
for	O
example	O
,	O
steam	O
power	O
generation	O
,	O
hydraulics	O
,	O
etc	O
.	O
</s>
<s>
In	O
the	O
automotive	O
sector	O
,	O
many	O
of	O
the	O
major	O
automotive	O
OEMs	O
are	O
using	O
Modelica	B-Application
.	O
</s>
<s>
Modelica	B-Application
is	O
also	O
being	O
increasingly	O
used	O
for	O
the	O
simulation	O
of	O
thermo-fluid	O
and	O
energy	O
systems	O
.	O
</s>
<s>
The	O
characteristics	O
of	O
Modelica	B-Application
(	O
acausal	O
,	O
object-oriented	B-Language
,	O
domain	O
neutral	O
)	O
make	O
it	O
well	O
suited	O
to	O
system-level	O
simulation	O
,	O
a	O
domain	O
where	O
Modelica	B-Application
is	O
now	O
well	O
established	O
.	O
</s>
