Standard operational semantics of the majority of concurrency models is defined
in terms of either sequences or step sequences, while standard concurrent history
semantics is usually defined in terms of partial orders, stratified order structures (or
structures equivalent to them as net processes).
It is commonly assumed (first argued by N. Wiener in 1914) that any system run
(execution) that can be observed by a single observer must be an interval order of
event occurrences.
However, generating interval orders directly is problematic for most models of
concurrency, as the only feasible sequence representation of interval order is by using
Fishburn Theorem (1970) and appropriate sequences of beginnings and endings of
events involved. It was shown by Janicki and Koutny in 1997 that concurrent histories
involving interval orders can be represented by interval order structures, but how these
interval order structures could be derived for particular concurrent systems was not
clear.
My original contribution to knowledge is defining an interval order semantics for
Petri Nets with Inhibitor Arcs. We start with introducing operational interval order
semantics, and then we generalize the concept of net process to represent the set of
equivalent executions modelled by interval orders.
Next we will show that our interval processes correspond to appropriate interval
order structures. Finally, we will prove that our model is equivalent to that of Janicki
and Yin (2015) where novel interval traces are used to represent equivalent executions.
We will also demonstrate that our model covers simpler cases where sequences or
step sequences were used to represent system runs. / Thesis / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/19007 |
| Date | 17 June 2016 |
| Creators | Alqarni, Mohammad |
| Contributors | Janicki, Ryszard, Computing and Software |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
Page generated in 0.0068 seconds