Geoscience Reference
In-Depth Information
2 The Core Platform R&D
2.1 Virtual Machine Selection
The GMO concept, as described in Kolᡠ(
2013
), has been implemented as a
software library named Geospatial Reference Interface for Internet Networks
(GRIFIN). In order for the GRIFIN implementation to be applicable and robust
few already existing technologies have been applied. The most crucial in this
regard was the selection of the VM technology. Note that the use of VM in our
approach is not a mere software engineering convenience for implementation or
porting to different operating systems. The role of the VM's byte-code relatively
to GMOs is similar to the importance of HTML relatively to Web pages. The con-
sequence of a future change to a different VM would have an analogy in changing
HTML to, let's say, PDF format—making all the previous content obsolete and
non-functional. Hence requirements on the VM technology are relatively strict and
include: non-proprietary solution, strong focus on backward compatibility, produc-
tion quality with commercial leadership, and widely established availability. Given
these priorities the HotSpot VM, which is the original VM used within the Java
ecosystem, stands out as a nearly unchallenged choice, despite its currently mar-
ginal availability on mobile platforms.
The GMO concept has been coded in form of an abstract class, which provides
access to the common representation of geographic space with time and scale to
an indexing mechanism associated with the space, and to custom functionality
needed by each individual GMO definition. Hence it is guaranteed that all imple-
menting subclasses and their GMO instances have these three properties. Concrete
examples of GMO definitions, which include references to the source code, are
available at:
http://griinor.net/examples
.
2.2 The Main Features of the Platform
In order to facilitate prototyping and the re-use of GMO models most of the exam-
ples utilize the Scala language and the GRIFIN Shell (GShell), which allows for
an interactive use. GShell can be used to create, manage and consume the geo-
spatial content on the GRIFIN platform. It has all management, server, and
remote access features available from a uniform environment and provides a way
to exchange and execute code on GRIFINs distributed network. This follows the
original vision of a space for collaboration on model development, and not just
a one-way publishing medium for static, predefined, and hard-to-change types of
geospatial information. Identical GMOs displayed in three different clients.
Figure
2
depicts the Strømsø city model and daily energy consumption per
building modelled as GMOs. While the model is relatively complex the software
