Types of Models in the DeMO Ontology

Discrete-event Modeling Ontology

 

Model Acronym

Model Name

Model Description

Citation

 

 

 

 

GSMP+SE

Generalized Semi-Markov Process (with Simultaneous Events)

A model of a stochastic process with countably many states in which state transitions are probabilistically triggered by event (or multiple events) occurrence and the time of event occurrence is specified by a stochastic clock structure associated with an event set.

 

(Hass and Shedler, 1987)

GSMP-SE

Generalized Semi-Markov Process (without Simultaneous Events)

Generalized Semi-Markov Process models (GSMP) without simultaneously occuring events.

 

(Glynn, 1983)

SMP

Semi-Markov Process

A  GSMP-SE with only one type of event. Events do not compete for each other and a single stochastic clock measures interevent time.

 

(Levy, 1954)

QN

Queuing Network

The state of a queuing network counts the occupancy of each place/node (service station) in the network.

 

(Jackson, 1963)

CTMC

Continuous Time Markov Chain

A continuous-time model of sequences of random variables with "memoryless" property. Represented by states with probabilistic transition rates. Can be viewed as SMP with Poisson distribution imposed on event clock.

 

(Kolmogorov, 1938)

DTMC

Discrete Time Markov Chain

A discrete-time model of sequences of random variables with "memoryless" property. Represented by states with probabilistic transitions occurring at discrete time. Can be viewed as SMP with geometric distribution imposed on event clock.

 

(Markov, 1913)

 

 

 

 

STA

Stochastic Timed Automata

State automata consisting of states and events (together with probabilistic transition function) and equipped with a stochastic clock structure associated with an event set (i.e. there’s a stochastic distribution function for each event that produces the time of event occurrence).

 

(D'Argenio et al., 1997)

PTA

Probabilistic Timed Automata

STA with deterministic transition function.

 

(Jensen, 1996)

TA

Timed Automata

STA with deterministic transition function and deterministic clock structure. Clock structure determines the time at which events occur.

 

(Alur, 1990)

SA

State Automata

An abstract model consisting of discrete states and rules defining transitions from state to state. (Think of a directed graph, where nodes represent states and arcs represent transition rules). Transitions are triggered by events that occur in some order, but no time of the event occurrence is specified (no clock structure).

 

(Moller, 1998) [survey]

DFA

Deterministic Finite Automata

State Automata with finitely many states.

 

(Huffman, 1954)

 

 

 

 

GSPN

Generalized Stochastic Petri Net

Marked Petri Nets with timed and immediate transitions. Timed transitions are probabilistic and determined by a stochastic clock structure.

 

(Marsan et al., 1984)

SPN

Stochastic Petri Net

.

 

(Molloy, 1982)

TPN

Timed Petri Net

GSPN with deterministic clock structure and transition function.

 

(Ramchandani, 1974)

PN

Petri Net

An abstract model that can be illustrated by a bipartite directed graph, with one set of nodes representing places and another set of nodes representing transitions. Each place may have a number of tokens which can move to another place when the corresponding transition is fired. Each arrangement of tokens (called marking) determines a state. Thus the states are not explicitly defined in the model.

 

(Petri, 1962)
(Peterson, 1977) [survey]

BPN

Bounded Petri Net

Petri Nets in which the number of tokens in each place is bounded from above.

 

FCN

Free Choice Net

Petri Nets in which transitions w/ input from multi-output place have no other input arcs.

 

(Hack, 1972)

 

 

 

 

EG

Event Graph

An event graph is a directed graph in which each node specifies an event and each directed edge indicates an event casuality relationship.

 

(Schruben, 1983)