Page 252 - DCAP601_SIMULATION_AND_MODELING

Simulation and Modelling

Notes ‘Entities’ (machines, parts etc.) from a library onto a frame. The entities could then be connected
in the desired order. Many of the advanced VIM simulation tools allow program code to be
attached to the entities and events, therefore making the model potentially more sophisticated
and flexible.

Did u know? Uses of Visualization and Simulation
Visualization and simulation are extensively used in the training of operational staff,
especially where the training cannot be carried out in real life e.g. shutting down the
reactor of a nuclear power station after an earthquake.

Object Oriented Simulation

Object Oriented techniques have been developed since the early 1960’s as a result of simulation
development (SIMULA). Until recently, the two were not coupled despite their original tandem
development. There are currently only a handful of Object Oriented simulation applications
available on a commercial basis; one of the most prominent of these is iBright Ltd’s ‘baseSim’.
The main difference between traditional program development and Object Oriented techniques
is the way in which the data and the program code are stored and manipulated. In traditional
software, the data and the program code are intermingled throughout the program, making
data security and integrity difficult to achieve (it is sometimes possible for one procedure to
cause knock-on effects as global data is changed). However, in Object Oriented simulation
software all data and procedures relating to a single entity (object) are encapsulated within an
object, with the object controlling its own interaction and data integrity permissions with other
objects. Clearly, the methods inside the object could cause similar knock-on effects, if poorly
implemented.
Object Oriented simulation tools, in particular iBright Ltd’s ‘baseSim’, are very powerful as they
make use of Object Oriented techniques such as modularity, class structure, inheritance, hierarchy
and polymorphism.

Statement from a Company about Discrete-system Simulation
Our Discrete-system Simulator (DSS) is used by INTRACOM, the largest Greek telecom
company. We shall expand DSS (in connection with the DSP library) to allow for the
specification, simulation and performance testing of distributed protocols for almost any
form of environment, including networks that allow hierarchical description, very fast
networks and heterogeneous networks with mobile units. The visualisation facility of DSS
will be enhanced so the user can see the protocol execution in very large networks in a
meaningful way through, e.g., a hierarchical description and graph-drawing techniques.
INTRACOM, and also INTRASOFT (the largest Greek software company), are interested in
the new DSS and DSP library for (1) simulating and testing distributed banking applications,
and (2) designing hardware for fast networks (routers and switches).
During the first year of ALCOM - IT, we established strong interactions with the industrial link
INTRAKOM/INTRASOFT a major Telecom and Systems House conglomerate of Companies.
After analysing the users’ needs, we identified a large algorithmic area which is a subset of the
area of on-line algorithms, namely the area of Call Admission Control (CAC) algorithms. Our
group and, in general, the ALCOM team has had already shown significant research on the issue.
Since the problem of Admission Control is currently addressing ATM network technology, we

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