Introspecting Agent-Introspecting Agent-Oriented Design Oriented Design PatternsPatternsManuel Kolp, T. Tung Do, Stéphane Faulkner and T. T. Hang Hoang

Presented byRachel Bock, Sam Shaw, Nicholas

Vance, Ashok Subramaniam, Nisha Mathew

OutlineOutlineIntroductionDescription of agents and

behaviorDesign Patterns

◦Pair Design Patterns◦Mediation Design Patterns

Conclusion

Agent CharacteristicsAgent CharacteristicsAutonomy – Agents have their

own internal thread of execution.Situateness – Agents perform

their actions in the context of a particular environment.

Flexibility – Agents must act to ensure goals are achieved in a dynamic and unpredictable environment.

Sociality and Sociality and CommunicationCommunication

Multi-Agent System (MAS) – environment that contains multiple agents.

Potentially huge number of agents.Each acts autonomously with its own goals.Problems arise involving coordination and

collaboration.Design patterns exist to help tackle these

issues.

Social Design PatternsSocial Design PatternsPair – direct interaction between

negotiating agentsMediation – intermediate agents

help other agents to reach agreement about an exchange of services

Pair Design PatternsPair Design PatternsBookingSubscriptionCall-For-ProposalsBidding

BookingBooking

SubscriptionSubscription

Call-For-ProposalsCall-For-ProposalsAgents Involved: Initiator, Participants

Description – The initiator requests

proposals for a specified service. To this request participants respond with their cost for the service. Of the proposals that the client receives he selects the one participator whose service he will use.

BiddingBiddingAgents Involved: Client, Service Provider Description – This pattern involves a

iterative bidding process. In each iteration the Client receives bids from Service Providers for a requested service. Once all the bids are receive the client makes one of four choices. The choices are for the client to either publish the current bid, raise the bid, cancel the bidding process, or accept the bid as the one it will be using.

Mediation Design PatternsMediation Design PatternsMonitorBrokerMatchmakerMediatorEmbassyWrapper

MonitorMonitorAgents Involved: Subscriber, MonitorDescription – The subscriber registers

to receive notification of events that the monitor watches for. When a the event occurs the monitor notifies all the subscribers that have registered for notification of the event.

BrokerBrokerThe broker agent is an arbiter It is an intermediary that requests

services from providers to satisfy the request of clients.

MatchmakerMatchmakerA matchmaker agent locates a

provider for a given service requested by a client.

It then lets the client interact directly with the provider(unlike brokers)

This provider handles all interactions between clients and providers.

Matchmaker DiagramMatchmaker Diagram

MediatorMediatorA mediator agent coordinates the

cooperation of service provider agents to satisfy the request of a client agent.

Mediator differs from matchmakers. A matchmaker simply matches providers with clients.

A mediator encapsulates interactions and maintains models of the capabilities of clients and providers over time.

Mediator DiagramMediator Diagram

EmbassyEmbassy

• Mediation Pattern• Embassy, external and local agents• Embassy agent translates messages between local and external agents

WrapperWrapper• Mediation Pattern• Incorporates a legacy system into a MAS• Wrapper, legacy and system agents• Wrapper agent interfaces system and legacy agents by acting as a translator.

Wrapper DiagramWrapper Diagram

Client Wrapper SourceClient

request Translate and send

Client request

answer

Source answer

Translate and send

ConclusionConclusionNew enterprise applications exist

in a changing environment.MAS architecture allow dynamic

structures which can change at run-time.

Patterns provides good approach to reuse architecture design knowledge.

Social patterns

ReferenceReference Introspecting Agent-Oriented

Design Patterns◦ Manuel Kolp, T. Tung Do, Stéphane

Faulkner and T. T. Hang Hoang