cresco spiii.5 project status 06-07-07
DESCRIPTION
CRESCO SPIII.5 Project status 06-07-07. Dip. Di Informatica Sistemi e Produzione Università di Roma Tor Vergata E. Casalicchio , E.Galli , S.Tucci. It's a software process able to work asynchrounsly and autonously in an particular environment - PowerPoint PPT PresentationTRANSCRIPT
Dip. Di Informatica Sistemi e Produzione Università di Roma Tor Vergata
E. Casalicchio, E.Galli, S.Tucci
CRESCO SPIII.5Project status 06-07-07
Università di Roma "Tor Vergata" - CRESCO-SPIII
What's an Agent
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It's a software process able to work asynchrounsly and autonously in an particular environment
An agent is identifiable, a discrete individual with a set of characteristics and rules governing its behaviors and decision-making capability.
It can perceive and interact with the world (environment and other agents)Agents have protocols for interaction with other
agents Every agent is identified by an own location,
capabilities and memory.Can adapt its behaviours according to its
experience Every agent has its own goal.
Intelligent agent can evaluate different plans and choose the best one
Università di Roma "Tor Vergata" - CRESCO-SPIII
What is ABM&S
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ABMS has its direct historical roots in complex adaptive systems (CAS)Systems are built from the ground-up
Important results can emerge in systems that are completely described by simple rules that are based on only local information
Results that may develop can be extremely sensitive to the initial conditions.
Simple rules can be used to understand much of the complexity observed in the real world
Università di Roma "Tor Vergata" - CRESCO-SPIII
Why ABM&S
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I. Allow to simulate a complex system composed by many subsystem
organize system hierarchicallydecomposition of an agent in multi-agentssimplify interactions between entities when it's to hard to represent them with equations
II. Customize the target system as required by the case under studyIII. Allow to study of unexpected pertubations on the interconnected infrastructuresIV. Study the behaviour of an infrastructure for a certain input more than a equationsV. Allow to give a whole picture of the system behaviourVI. Allow to use external specific simulators, wrapping them with a agent
Università di Roma "Tor Vergata" - CRESCO-SPIII
Independent or sequential simulation
E.g.:• Simulation of the effect of
fault in the power grid in [t1, t2].
• From the output i know that Roma-Est city’s area will experiment a blackout [t1’,t2’]
• I use such result to build a scenario for the simulation of the communication network behavior in [t1,t2] introducing a blackout starting at t1’ and ending at t2’
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Sim i
Output processing
and analysis
Sim j
Output processing
and analysis
Sim k
Output processing
and analysis
IN_i OUT_i
OUT’_i
IN_j
IN_i,j
OUT_j
OUT_k
OUT’_j
IN_k
IN_i,k
IN’_k
OUT’_k
Università di Roma "Tor Vergata" - CRESCO-SPIII
Interdependent or distributed simulation
E.g.: simulation of the transportation net., the power grid and the comm. net. in Roma in [t1,t2]
• At time t’>t1 the power grid experiment a failure.• Such failure propagates and have a direct effect at time t’+dt on a
node of the comm. net.• The failure of a comm. net. node has an impact on a not well known
simulated system that directly or indirectly use the CommNet, e.g. the transp. net.6
Local Ouputs e_i(t)
SIM a
RMI
SIM b
RMI
SIM d
RMI
SIM c
RMI
GRID and/or SOA communication
infrastructure relying on the internet
e_i(t)
e_i(t)
e_i(t)
Local input parameters
Collector
RMI
Database
Output processing
and visualization
o_c(t)
o_a(t) o_b(t)
o_d(t)
o_a(t), o_b(t) o_c(t) o_d(t)
Università di Roma "Tor Vergata" - CRESCO-SPIII
Advantages & Disadvantages
Università di Roma "Tor Vergata" - CRESCO-SPIII7
Sequential:-/+ macroscopic
int. analysis- Do not emerge
unknown interdependencies
+ Does not require simulators re-engineering
Distributed:+ microscopic int.
analysis+ could emerge
unknown interdependency
- Requires simulators re-engineering or adaptation
Introduction to a custom approach with Repast and Omnet
Università di Roma "Tor Vergata" - CRESCO-SPIII8
We have used Repast as Toolkit for ABM&SWe have modeled both some Infrastructure
and simple users which use themWe have used OMNeT++ as framework
DES (discrete event simulation) to simulate Communication Network
We have developed a distributed approach with Repast and OMNeT to study an our defined simple scenario
Introduction to a custom approach with Repast and Omnet (cont.)
Università di Roma "Tor Vergata" - CRESCO-SPIII9
In Repast has been simulated interaction between different infrastructures.Every Infrastructure is an agent with its behaviour, memory and so on.The communication network is modelled using a specialized simulator:
OmnetThe agents which communicate using the Communication networks
use specific calls of the: CommunicationNetworkAgent V.Cardellini, E. Casalicchio, E. Galli. Agent-based Modelling of
Interdependencies in Critical Infrastructures through UML. In Proc. of Spring Simulation Multiconference 2007 (SpringSim07)
REPAST OMNET
InternetR1
R2
R3
R4R5IS4CEM
Wounded
CMN
HCC1Soccurer
Wounded
Soccurer
IS4CEM
HCC1
Implementation of model: Network
Università di Roma "Tor Vergata" - CRESCO-SPIII10
Based on two level:Interactions between infrastructures are controlled by
agents of RepastSimulation of communication network developped with
OMNet++ Developped an interface between Repast and
OMNet++The communication network is built in OMNet++
Setting of capacity of lynks between agentsSimulation of workload
The CommunicationNetwork Class of Repast control failure and can set new capacity for a link
Agents use CommunicationsNetwork’s method to send message to other agents on network
Implementation of model:Network (cont)
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Example of sending of a message:Every agent that wants to send a message on network
comunicates its necessity to Communication Network Class
Communication Network prepares messages to send and uses the interface with OMNet++. Simulation is paused.
OMNet++ calculates routing and time for every new message and informs Communication Network, if any message is arrived at destination. The Communication Network Class determine if there is a failure in the communication (e.g. with a timeout).
Communication Network schedules reception of messages for every receiver-agents and the simulation restarts
Some screenshots: Repast & Omnet
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Some screenshots: Graphs with Omnet
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Some screenshots: GUI of Omnet
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Conclusions
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Study of the common scenarioCreate an interface for every Infrastructure
Simulator Study of interdependency between
different infrastructuresMapping every infrastructure to a
geographic locationUse of GIS or Google's API
Introduce a more complex fuzzy-set rules for every actors that we want to model