<s>
The	O
SHIWA	B-Operating_System
project	I-Operating_System
(	O
Sharing	O
Interoperable	O
Workflows	O
for	O
large-scale	O
scientific	O
simulations	O
on	O
Available	O
DCIs	O
)	O
within	O
grid	B-Architecture
computing	I-Architecture
was	O
a	O
project	O
led	O
by	O
the	O
LPDS	B-Operating_System
(	O
Laboratory	O
of	O
Parallel	O
and	O
Distributed	O
Systems	O
)	O
of	O
MTA	O
Computer	O
and	O
Automation	O
Research	O
Institute	O
.	O
</s>
<s>
The	O
SHIWA	B-Operating_System
project	I-Operating_System
developed	O
and	O
deployed	O
the	O
SHIWA	O
Simulation	O
Platform	O
(	O
SSP	O
)	O
to	O
enable	O
infrastructure	O
and	O
workflow	O
interoperability	O
at	O
two	O
levels	O
:	O
</s>
<s>
They	O
are	O
based	O
on	O
different	O
middleware	B-General_Concept
stacks	O
that	O
provide	O
an	O
abstraction	O
layer	O
between	O
computer	O
resources	O
and	O
applications	O
.	O
</s>
<s>
For	O
example	O
,	O
NGS	O
and	O
TeraGrid	O
are	O
built	O
on	O
the	O
Globus	O
Toolkit	O
[	O
Foster	O
2006 ]	O
,	O
EGEE	O
on	O
gLite	O
[	O
gLite	O
n.d.	O
]	O
,	O
DEISA	O
relies	O
on	O
both	O
the	O
Globus	O
Toolkit	O
and	O
Unicore	B-General_Concept
[	O
Erwin	O
and	O
Snelling	O
2002 ]	O
,	O
while	O
D-Grid	O
is	O
executed	O
under	O
gLite	O
,	O
the	O
Globus	O
Toolkit	O
and	O
Unicore	B-General_Concept
.	O
</s>
<s>
In	O
its	O
effort	O
to	O
create	O
the	O
next	O
generation	O
of	O
pan-Europe	O
DCI	O
,	O
EGI	O
will	O
face	O
unprecedented	O
challenges	O
related	O
to	O
the	O
heterogeneity	O
of	O
national	O
grid	O
infrastructures	O
,	O
resources	O
and	O
operating	O
middleware	B-General_Concept
.	O
</s>
<s>
Interoperability	O
among	O
DCIs	O
is	O
hardly	O
achieved	O
at	O
the	O
middleware	B-General_Concept
level	O
though	O
.	O
</s>
<s>
It	O
directly	O
addresses	O
the	O
challenges	O
related	O
to	O
(	O
i	O
)	O
scientific	O
experiments	O
design	O
through	O
simulation	O
workflows	O
description	O
and	O
(	O
ii	O
)	O
middleware	B-General_Concept
heterogeneities	O
encountered	O
among	O
the	O
many	O
existing	O
DCIs	O
through	O
workflow	O
interoperability	O
techniques	O
.	O
</s>
<s>
In	O
so	O
doing	O
,	O
it	O
will	O
provide	O
access	O
to	O
Grids	O
built	O
on	O
gLite	O
and	O
Globus	O
middleware	B-General_Concept
to	O
create	O
production-level	O
services	O
to	O
run	O
workflow-based	O
large-scale	O
simulations	O
.	O
</s>
<s>
The	O
targeted	O
middleware	B-General_Concept
and	O
workflow	O
systems	O
are	O
depicted	O
by	O
components	O
with	O
bold	O
borders	O
in	O
Figure	O
1.1.1	O
.	O
</s>
<s>
The	O
project	O
will	O
use	O
existing	O
Grid	O
middleware	B-General_Concept
interoperability	O
solutions	O
enabling	O
access	O
to	O
gLite	O
and	O
Globus	O
based	O
Grids	O
such	O
as	O
the	O
Austrian	O
Grid	O
,	O
D-Grid	O
,	O
EGEE	O
and	O
NGS	O
.	O
</s>
