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movement) or lead to the creation of appropriate events (e. g., if
an agent sends a radio transmission, the simulation engine has to
generate transmission events for the receiving agents).
Endogenous effectors
of an agent do not affect the surrounding
environment but only an agent itself. These effectors are used to
represent an agents' internal reasoner and affect an agents' internal
attributes (e. g., due to a reasoning or planning process).
The actual behavior of an agent is therefore described by
sensor-
effector-chains
which couple sensor and effector actions depending on
the events received by an agent.
Definition 21 (Sensor-effector-chain)
A
sensor-effector-chain
is
a combination of sensors and effectors of an agent for the purpose of
specifying its behavior.
The combination of sensors and effectors in a sensor-effector-chain is
defined implicitly. Each sensor and effector may trigger endogenous
events which in turn trigger another sensor or effector of an agent.
Thus, a sensor-effector-chain is determined by the events triggered by
the sensors and effectors of an agent.
As an example, Figure 6.6 illustrates event processing. From time
t
0
to
t
1
agent 2 activates one of his effectors (in this case, the send-
effector) to send a radio transmission. At the end of the effector
action, propagation of the radio signal begins. The communication
range of agent 2 is indicated by the dashed circle; accordingly only
agent 1 is within communication range. At time
t
2
the radio signal
has reached agent 1 and a receive-event is generated which agent 1
perceives with one of its sensors.
Example: Firespread
Figure 6.7 illustrates the sensor-effector-
chains of fireman-agent and firebug-agent. A fireman-agent pos-
sesses the following sensors and effectors:
Perceive: Perception of the environment, duration: 1 time step
