The Vision of a RealWorld Simulator - Programming GPS and OpenStreetMap Applications with Java - page 19

Measuring realistic behavior is what the project in this topic is all about.
(How) can you distinguish two GPS traces, when one is received live from
a moving car and the other from a car simulation? It is all a matter of
the degree of reality required and the similarity of the behavior to the real
world.
Similar to the fundamental Java Object , other more sophisticated and
specialized objects can be extended from RealObject . A RealCar might add
many attributes to specialize the RealObject on the domain car. Step by
step, the car can be enriched by an engine, a value for the current tank
reading, etc.

2.5 Real-Object Applications (ROApps)

We dened RealObject s to specify behavior and the internal coding of phys-
ical objects. The RO can be associated with a client program running on
a PC. By connecting to a server and logging on, the RO becomes part of a
real-object application or ROApp. Participating ROs can interact through
a ROApp, while the ROApp serves as the third party to propagate events
between ROs, observe the RO's behavior, and disqualify them for misbe-
havior.

A real-object application (ROApp) serves as an external environment
for RealObject s. In order to enter the environment ROs have to conform to
interfaces. The minimum requirement for all RO{ROApp combinations is
space and time. The ROApp provides universal coordinates and time for
all ROs, while ROs have to be able to report their location at any time.
The ROApp serves as a referee for all ROs and propagates information
between ROs.

Definition 2.2
Initial RoApp
vision

Technically an RO is a client application and the ROApp is a server
application.
This vision does not mention concrete implementations of authentica-
tion, authorization, etc. For example, a ROApp could provide a race track
and allow RealCar s to log on and race against one another. The ROApp
would be in control to start the race after having approved each car. During
the race, the ROApp would propagate collisions between cars and exclude
cars for violating racing rules.
ROApp laws are breakable and should therefore be referred to as rules,
as opposed to laws, such as physical laws, which a RealObject obeys. Nat-
urally each client can use any available ROApp information in its internal
implementation, for example to guide a car around a trac jam in the
ROApp scenario.