The ACL Cabin Case in Negotiation Process

Approvedforpublicrelease;distributionisunlimitedACLNegotiationScenarioandProtocolbyJonahTsaiZeynoAygenUlrichFlemmingJamesSnyder3ABSTRACTThisreportpresentsanegotiationprotocol,representation,andtwonegotiationcasesfortheACLproject.Inorderforthereaderstohaveabetterunderstandingoftheproposednegotiationmecha-nism,westartwithabriefintroductionofportionsoftheACLarchitecturethatarerelatedtonegotiation,conflictmanagementintheACLproject,andlaythefoundationoftheproposednegotiationscenario.4FOREWORD5FOREWORD41ACLARCHITECTURERELATEDTONEGOTIATION............................6ACLAgentsandAgentCommunicationScopeConceptandObjectMappingOML-BasedDesignRepresentationMapping2CONFLICTMANAGEMENTINTHEACLPROJECT............................12ConflictDetectionRationalization&ConflictResolution3NEGOTIATIONPROTOCOL..................................................15ScopeDefinitionsProtocolSpecificationOMLRepresentationoftheConflictObject4NEGOTIATIONCASES.......................................................20TheACLCabinCaseinNegotiationProcessNegotiationCaseINegotiationCaseIIREFERENCES..............................................................2561ACLARCHITECTURERELATEDTONEGOTIATIONThissectionpresents1).thedefinitionofanagentintheACLproject,2).anagentcommunicationmechanismusingconceptmapping,3).theprominentissuesinvolvedinconceptmappingandanOML-basedconceptmappingmechanism.1ACLAgentsandAgentCommunicationScopeAnagentisasoftwareconfigurationataspecificsitethat1.supportsaspecificdesigntask,whichmayinvolvehumaninteractionandintervention,2.generatesdesigninformationinitsowninternalrepresentation,and3.isabletocommunicateitsdesigndecisionstootheragentsatdifferentsites.Basedonagroupdecision,theACLprojecttakesade-centralizedapproachtoagentcouplingbecausesoftwareusedintheACLprojectbytheparticipatingagentsaresodiversethatforpragmaticreasons,acommondesignrepresentationsharedbyallagentscannotbefound.Thereisalsonocentralagentcontrol-lingtheschedulingofagentactivities.Thetop-levelagentconnectionsintheACLprojectareillustratedinFigure1;theyaremanagedbyafacilitator.2.Figure1.Top-LevelACLAgentConnectionThelackofacommondesignrepresentationthatwouldbesharedbyallagentsintheACLprojectimpliesthefollowing:1.Thesystemneedsamappingmechanism.Conceptsandobjectsindifferentlocalrepresentationsmustbemapped,orevenre-synthesized,whentheyarecommunicatedamongagents.1.Snyder,J.andFlemming,U.(1994)ACLObjectModelSpecificationLanguage,reportaccessiblefrom(1995).“DevelopmentofaMulti-InstitutionalTestbedforCollaborativeFacilityEngineeringInfrastructure”.InJ.P.Moshen(Ed.)ProceedingsoftheSecondCongressonComputinginCivilEngineering.pp1308-1315.StructureAgentArchitectureAgentFacilitator*AgentCollaborationEnvironment(ACE)isanagentarchitectureintheACLproject.Itintergratesanenergyanalysisagent,anowneragent,andaprojectmanagementagent.ACE*72.Notallagentshaveaccesstothewholedesign;infact,anagentonlyseesthoseportionsofadesignthatitunderstands.Theagentshavethefreedomtochooseanappropriatedatastorageandsessionmanage-mentscheme.However,thisdoesnotruleouttheneedsforacentralizedpersistentstorage.3.Itislikelythatanagentmaycreateadditionalversionsofanobjectotherthantheversionthatisbroad-casttootheragents.Therefore,synchronizationofobjectsbecomesanimportantissue,whichisnotpursuedinanydepthintheACLproject.4.Directnegotiationbetweenagentsneedsamappingmechanism.5.Sincethereisnocentralagentcontrollingtheschedulingofagentactivities,negotiationbetweenagentswillhavetofollowastrictprotocol.6.Conflictdetectionwillbetriggeredbydataupdates.7.Aconflictschemewillbesharedbyallagentsandtherewillbeacentralizedconflictmanagementmechanism.Agentsmaybestructuredinternallyinahierarchicalfashion.Buthowother“peer”agentsaresubdi-videdisnoconcernforanagent.Whenweusetheterm“otheragents”,werefertotheagentsinthesameagentcommunicationscope.Anagentcommunicationscopeiscomposedofaparentagentandallitsdirectchild-agents,seeFigure2.Notethataparentagentmayonlybeaconceptualagentthatdoesnotexistphys-ically.Asaresult,anagentitselfisviewedasablack-boxfromtheoutsidenomatterhowmanysub-agentsitiscomposedof.Figure2.AgentCommunicationScopeConceptandObjectMappingTheloosecouplingofagentsintheACLprojectraisestheneedsformappingbetweenthedifferentconceptsusedbydifferentagents.Whenagentscommunicatewitheachother,theseconceptsneedtobemappedcorrectlyforconveyingdesigndecisionsamongagents.Conceptmappingmayrequireattributetransformationsandobjectre-synthesis.Thesetransformationsandre-synthesesmayrequireattributeextractionfromrelatedconceptsotherthantheconceptbeingmapped.Forexample,Figure3andFigure4showtwodifferentwallconcepts,whereonemaybeusedbyanarchitectureagent,andtheotherbyastruc-turedesignagent.3BADCEFGAgentCommunicationScopeHI8Figure3.ArchitecturalWallandStructuralWallFigure4.OMTModelofArchitecturalWallandStructuralWall3.Rumbaugh,J.,Blaha,M.,Premerlani,W.,Eddy,F.,&Lorensen,W.(1991).Object-Orient