2.1 Modeling and Simulation
23
Solutions/
understanding
Real world
problem
Modelling and general
project objectives
Model content:
scope and level of detail
Experimental
factors
provides
accepts
determine
Conceptual Model
Conceptual Model
Validation
Model
Verification
Scenario
Verification
Operational
Validation
Justification to use
hybrid approaches
Responses
Computer Model
Sub-model definition
Definition of discrete and
continuous interaction points
Identification of mode of
interaction for sub-models
Figure 2.6 Stages of a hybrid simulation study. Adapted from [Ro2008, p. 280; El+2018,
p. 1501; Ch2009, p. 48]
In combined simulation models, three basic forms for linking discretely changing and continuously changing state variables can occur [Pr1995, pp. 61 ff.]:
(1) A discrete event can cause a discrete change in the value of a continuous
state variable. (2) A discrete event can change the relationships that determine the
behavior of a continuous state variable at a particular time. (3) Reaching a defined
limit by a continuous state variable can trigger a discrete event.
The interaction of combined ABS-DES models is different. While the behavior
of entities in DES is determined by rules which may range from if-then conditions to highly complex algorithms, agents are autonomous individuals which have
the ability to act independently, to learn from the past and to adapt their behavior for the future. Their behavior is determined by learning algorithms and the
abstract presentation of the relationships between the system states and the individual agent. Agents communicate by passing signals or messages from one to
another and they can pass messages to their environment [Br2014, p. 1541]. Thus,
either messages or occurring events affect the behavior of agents and entities in a
combined model.
23
Solutions/
understanding
Real world
problem
Modelling and general
project objectives
Model content:
scope and level of detail
Experimental
factors
provides
accepts
determine
Conceptual Model
Conceptual Model
Validation
Model
Verification
Scenario
Verification
Operational
Validation
Justification to use
hybrid approaches
Responses
Computer Model
Sub-model definition
Definition of discrete and
continuous interaction points
Identification of mode of
interaction for sub-models
Figure 2.6 Stages of a hybrid simulation study. Adapted from [Ro2008, p. 280; El+2018,
p. 1501; Ch2009, p. 48]
In combined simulation models, three basic forms for linking discretely changing and continuously changing state variables can occur [Pr1995, pp. 61 ff.]:
(1) A discrete event can cause a discrete change in the value of a continuous
state variable. (2) A discrete event can change the relationships that determine the
behavior of a continuous state variable at a particular time. (3) Reaching a defined
limit by a continuous state variable can trigger a discrete event.
The interaction of combined ABS-DES models is different. While the behavior
of entities in DES is determined by rules which may range from if-then conditions to highly complex algorithms, agents are autonomous individuals which have
the ability to act independently, to learn from the past and to adapt their behavior for the future. Their behavior is determined by learning algorithms and the
abstract presentation of the relationships between the system states and the individual agent. Agents communicate by passing signals or messages from one to
another and they can pass messages to their environment [Br2014, p. 1541]. Thus,
either messages or occurring events affect the behavior of agents and entities in a
combined model.