Figure 3: Comparison of relations that can be used in
queries prior to applying an ontology reasoner (left) and
after having applied an ontology reasoner (right). Oval
elements indicate concepts, the rectangular element is an
instance of the entity “CompactCar”, all directed arrows
indicate “is-a” subsumption relations, fully drawn lines
indicate explicit relations and dotted lines indicate
relations that have been made explicit through an ontology
reasoner.
The reasoning functionality described above is
essential for making the full power of the ontology
model available to users of the data store (see Ulicny
et al., 2008 for benefits and problems to be
addressed in this context). However the production
rule system implemented as part of the MOSAIC
system allows users to automatically analyse data in
the data store as these become available and to
perform specific actions within the system when the
left-hand-side “if” conditions of a production rule
are satisfied.
To achieve this, the well-known JBoss Drools
(JBoss, 2014) production rule engine has been
integrated with the MOSAIC data store via a
connector that allows it to access the data of the
MOSAIC ontology data model and a custom data
model representation of the MOSAIC data model for
use with JBoss Drools has been implemented.
Drools is an efficient production rule processing
engine for which the powerful Drools Rule
Language has been developed. This language
facilitates complex event processing such as rules
with temporal order or other complex event
conditions, which sets the functionalities of the rule
engine apart from simpler custom production rule
engines and from query languages such as SPARQL.
The Drools Rule Language divides rules into
left-hand-side “if” and right-hand-side “then” parts;
actions for the right-hand-side of a rule can be
defined in the Java programming language and can
include calls of custom methods, so that in principle
any functionality that can be implemented in Java
can be triggered via a Drools rule once implemented.
In MOSAIC, different notification functions that
alert analysts or operators to interact with CCTV
cameras (e.g. to turn a camera to a new position) and
functionalities that add new information derived
from reasoner output to the MOSAIC data store
have been implemented. The code snippet given in
Figure 4 shows the formulation for a simple example
Drools rule that would fire and send an email once a
specific vehicle has been spotted at a specific
location.
Rules can be evaluated every time additional
data is made available in the data store or be
configured with cool down periods or number of
times to fire in order to avoid excessive numbers of
rule activations.
In combination with MOSAIC user interface
components and map-based visualisation systems,
the decision support system allows the combination
of various complex situations that may be of interest
to intelligence analysts or CCTV operators. In
particular in combination with geospatial
visualisation as described in another contribution
submitted to this event (Badii et al., 2014), the
decision support system can be a powerful aid when
dealing with large amounts of simultaneously
incoming data as is the case for instance for CCTV
operators.
5 CONCLUSION
The work described in this paper describes the
components of the MOSAIC system that are
concerned with integrating data from heterogeneous
data sources so that they can be accessed in a unified
manner and with empowering users to define rules
that reflect complex information needs as they may
arise when protecting critical assets from a wide
range of possible threats.
The solution described in this contribution
furthermore shows how the currently prevalent
problems of segregation of data in data silos and the
subsequent need for large amounts of manual labour
in navigating, collating and evaluating the gathered
data can be supported and made more efficient for
intelligence analysts and how personnel such as
CCTV operators can be supported by intelligent
integrated systems.
The work presented here is a foundation that is
used in the MOSAIC system and it is anticipated
that it may be used for future research on new
Th ing
Car
CompactCar
CompactCarABC
Th ing
Car
CompactCar
CompactCarABC
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