Information Technology Reference
In-Depth Information
8.2.3.3 Profile-Aware packages
The availability of dependencies and community profiles allows deriving
pack-
ages
, either for archiving or for dissemination, that are
profile-aware
. For instance
OAIS [
122
] distinguishes packages to AIPs (Archival Information Packages), which
are Information Packages consisting of Content Information and the associated
Preservation Description Information (PDI) and DIPs (Dissemination Information
Packages), that are derived from one or more AIPs as a response to a request of an
OAIS.
The availability of explicitly stated dependencies and community profiles,
enables the derivation of packages that contain exactly those dependencies that
are needed so that the packages are intelligible by a particular DC profile and are
redundancy-free. For example in Fig.
8.5
if we want to preserve the file Mars.fits for
astronomers (users with DC profile
u
1
) then we do not have to record any depen-
dencies since the file is already intelligible by that community. If on the other hand
we want to preserve this module for the community of ordinary users (users with
DC profile
u
2
), then we must also record the modules that are required for this
community in order to understand the module.
Definition 4
The
(dissemination or archiving) package
of a module
t
with respect
to a user or community
u
, denoted by,
Pack( t , u)
, is defined as:
Pack( t , u)
=
(t, Gap(t, u))
Figure
8.9
shows the dependencies of a digital object
o
1
and three DC profiles.
The dependencies in the example are conjunctive. The packages for each different
DC profile are shown below:
o1
t1
DC2 = {t3,t5}
t2
DC1 = {t2}
t3
t4
t5
t6
DC3 = {t7,t8}
t7
t8
AIP of o1 wrt DC1
AIP of o1 wrt DC2
AIP of o1 wrt DC3
Object = o1
DCprofile = DC1
deps = {t1,t3}
Object = o1
DCprofile = DC2
deps = {t1,t2,t4}
Object = o1
DCprofile = DC3
deps = {t1,t2,t3,t4,t5,t6}
Fig. 8.9
Exploiting DC Profiles for defining the “right” AIPs
