Please check our Instructions to Authors and send your manuscripts to nifs.journal@gmail.com. Next issue: September/October 2024.
Deadline for submissions: 16 November 2024.
Generalized nets: Difference between revisions
start this stub |
add new sections |
||
| Line 1: | Line 1: | ||
'''Generalized nets''' (''GNs'') constitute a discrete tool for universal description of adaptable, flexible, structured and reusable models of complex systems with many different and interacting components, not necessarily of the homogeneous structure and origin, usually involved in parallel, simultaneous activities. Generalized nets represent a significant extension and generalization of the concept of [[Petri nets]], as well as of other [[Extensions of Petri nets|Petri nets extensions and modifications]]. | '''Generalized nets''' (''GNs'') constitute a discrete tool for universal description of adaptable, flexible, structured and reusable models of complex systems with many different and interacting components, not necessarily of the homogeneous structure and origin, usually involved in parallel, simultaneous activities. Generalized nets represent a significant extension and generalization of the concept of [[Petri nets]], as well as of other [[Extensions of Petri nets|Petri nets extensions and modifications]]. | ||
== Components of a generalized net == | |||
A generalized net consists of: | A generalized net consists of: | ||
* a static structure, | * a static structure, | ||
| Line 8: | Line 9: | ||
The '''''static structure''''' consists of objects called ''[[transition]]s'', which have input and output ''[[place]]s''. Two transitions can share a place, but every place can be an input of at most one transition and can be an output of at most one transition. | The '''''static structure''''' consists of objects called ''[[transition]]s'', which have input and output ''[[place]]s''. Two transitions can share a place, but every place can be an input of at most one transition and can be an output of at most one transition. | ||
The '''''dynamic structure''''' consists of ''[[token]]s'', which act as information carriers and can occupy a single place at every moment of the GN execution. The tokens pass through the transition from one input to another output place; such an ordered pair of places is called ''[[transition arc]]''. The tokens' movement is governed by conditions (''predicates''), contained in the [[predicate matrix]] of the transition. | The '''''dynamic structure''''' consists of ''[[token]]s'', which act as information carriers and can occupy a single place at every moment of the GN execution. The tokens pass through the transition from one input to another output place; such an ordered pair of places is called ''[[transition arc]]''. The tokens' movement is governed by conditions (''predicates''), contained in the [[predicate matrix]] of the transition. | ||
The information carried by a token is contained in its [[token characteristics|characteristics]], which can be viewed as an associative array of characteristic names and values. The values of the token characteristics change in time according to specific rules, called ''[[characteristic function]]s''. Every place possesses at most one characteristic function, which assigns new characteristics to the incoming tokens. | The information carried by a token is contained in its [[token characteristics|characteristics]], which can be viewed as an associative array of characteristic names and values. The values of the token characteristics change in time according to specific rules, called ''[[characteristic function]]s''. Every place possesses at most one characteristic function, which assigns new characteristics to the incoming tokens. Apart from movement in the net and change of the characteristics, tokens can also split and merge in the places. | ||
The '''''temporal components''''' describe the time scale of GN execution. ''Temporal conditions'' control the transitions' moments of activation and duration of active state. Various other tools for fine tuning of the GN functioning are provided in the form of ''priorities'' of separate transitions, places and tokens, as well as ''capacities'' of places and transitions arcs. | The '''''temporal components''''' describe the time scale of GN execution. ''Temporal conditions'' control the transitions' moments of activation and duration of active state. Various other tools for fine tuning of the GN functioning are provided in the form of ''priorities'' of separate transitions, places and tokens, as well as ''capacities'' of places and transitions arcs. | ||
=== Graphic representation === | |||
== Formal description == | == Formal description == | ||
== | === Algorithms for tokens transfer === | ||
== Reduced generalized nets == | |||
== Extended generalized nets == | |||
== Theoretical aspects of generalized nets == | |||
=== Algebraic aspect === | |||
=== Topological aspect === | |||
=== Logical aspect === | |||
=== Functional aspect === | |||
* Global operators | |||
* Local operators | |||
* Hierarchical operators | |||
* Reducing operators | |||
* Extending operators | |||
* Dynamic operators | |||
== Construction of generalized nets == | == Construction of generalized nets == | ||
== Modelling and simulation == | == Modelling and simulation == | ||
Revision as of 23:02, 2 November 2008
Generalized nets (GNs) constitute a discrete tool for universal description of adaptable, flexible, structured and reusable models of complex systems with many different and interacting components, not necessarily of the homogeneous structure and origin, usually involved in parallel, simultaneous activities. Generalized nets represent a significant extension and generalization of the concept of Petri nets, as well as of other Petri nets extensions and modifications.
Components of a generalized net
A generalized net consists of:
- a static structure,
- a dynamic structure,
- temporal components.
The static structure consists of objects called transitions, which have input and output places. Two transitions can share a place, but every place can be an input of at most one transition and can be an output of at most one transition.
The dynamic structure consists of tokens, which act as information carriers and can occupy a single place at every moment of the GN execution. The tokens pass through the transition from one input to another output place; such an ordered pair of places is called transition arc. The tokens' movement is governed by conditions (predicates), contained in the predicate matrix of the transition.
The information carried by a token is contained in its characteristics, which can be viewed as an associative array of characteristic names and values. The values of the token characteristics change in time according to specific rules, called characteristic functions. Every place possesses at most one characteristic function, which assigns new characteristics to the incoming tokens. Apart from movement in the net and change of the characteristics, tokens can also split and merge in the places.
The temporal components describe the time scale of GN execution. Temporal conditions control the transitions' moments of activation and duration of active state. Various other tools for fine tuning of the GN functioning are provided in the form of priorities of separate transitions, places and tokens, as well as capacities of places and transitions arcs.
Graphic representation
Formal description
Algorithms for tokens transfer
Reduced generalized nets
Extended generalized nets
Theoretical aspects of generalized nets
Algebraic aspect
Topological aspect
Logical aspect
Functional aspect
- Global operators
- Local operators
- Hierarchical operators
- Reducing operators
- Extending operators
- Dynamic operators
Construction of generalized nets
Modelling and simulation
Software implementation of generalized nets
See also
- Theory of generalized nets
- Applications of generalized nets
- History of generalized nets
- List of GN terms
