Environmental Engineering Reference
In-Depth Information
The end user interacts with the system by means of
SeamGUI
, a browser based
application providing a Graphical User Interface (GUI) running as client of the web
(server) application. The client-server architecture of SEAMLESS-IF allows for
future clients to be developed and linked to the existing server, in order to cater for
specific needs of different user groups. The currently available SeamGUI client
includes two task specific user interfaces:
-
PE GUI
, the policy expert GUI: through this interface an expert can evaluate
the impact of alternative agricultural policies from the different aspects of
sustainability;
-
IM GUI
, the integrative modeller GUI: the module that guides the end-user to
manage projects and request the execution of model chains, in order to produce
results to be later used by policy experts.
SeamGUI requires a user to log in to the system first, and then decides based
on the user permissions which task user interface to show. It then interacts
with the software services provided by the
SeamServer
, the web-based application
framework built on the core classes provided by
SeamFrame
. The latter is a
modelling framework purposely designed to develop integrated assessment
tools, thanks to:
-
The
Modelling Environment
, which is a programming framework that
offers a series of facilities to encapsulate and wrap existing models for
execution by the processing environment. It allows to deliver model components
wrapped by a SeamFrame specific interface, compliant with the Open Modelling
Interface (OpenMI) standard (
www.openmi.org
)
(Gijsbers and Gregersen
2005, Gijsbers et al. 2006), so that it can be executed by the Processing
Environment (see below). Future versions of the Modelling Environment could
incorporate interactive modelling facilities.
The
-
Processing Environment
is both a programming framework and a
software application that retrieves requests for the execution of chains of
model-components from a queue. This queue is represented by a table in
the database, and experiment processing requests can be entered through the
SeamGUI. The Processing Environment enables model composition and
execution. The actual exchange of data among the models in a chain is based on
the OpenMI that provides a standardized interface to define, describe and transfer
data between software components that run sequentially. This choice was made
based on technical and functional requirements and the possibility offered to
re-use legacy models. The use of the central database to store the queue allows
for multiple instances of the Processing Environment to run in parallel.
External to the layered architecture, but fundamental for SEAMLESS-IF, is the
Knowledge Manager
, that provides access to and manages persistency of data in
the databases. SeamFrame uses the domain model and classes generated for it from
the SEAMLESS ontology by the Knowledge Manager. These classes become
part of the Modelling Environment. Through a Hibernate-based object relational
mapping (
www.hibernate.org
) the domain model is stored in databases.
