Simulate coupled model in real time mode- centralized wayRTCentralCoord CoupledSimulator1 Atoimc1CoupledSimulator3 Atoimc3CoupledSimulator2 Atoimc2simulators.tellAll(initialize“)simulators.AskAll(“nextTN)myThread.sleep( nextTN currentTime)simulators.tellAll(computeInputOutput“)simulators.tellAll(sendMessages)simulators.tellAll(DeltFunc“)putMessageputMessageputMessageSequence Diagram of InitializationRTcoordinatorTime synchronizationAtomicModelAtoimc3RTSimulatorsideMessagesideMessage RTSimulatorRTSimulatorAtomicModelAtomicModelsideMessageFlat Decentralized Distributed Real-Time Simulation with ActivitiesReal WorldDEVS ActivityoutputFromActivitySimulate hierarchical coupled model in fast modeCoordinator CoupledCoordinator CoupledSimulator4 Atomic4CoupledSimulator3 Atomic3simulators.tellAll(initialize“)simulators.AskAll(“nextTN)simulators.tellAll(computeInputOutput“)simulators.tellAll(sendMessages)simulators.tellAll(DeltFunc“)putMessageputMessageputMessageCoupledSimulator1 CoupledSimulator2 Atomic1Atomic2putMessageputMyMessageCoupled1sendDownMessageSimulate hierarchical coupled model in real time mode- Centralized wayRTCentraCoord CoupledCoordinator CoupledSimulator4 Atomic4CoupledSimulator3 Atomic3putMessageputMessageputMessagesimulators.tellAll(initialize“)simulators.AskAll(“nextTN)myThread.sleep( nextTN currentTime)simulators.tellAll(computeInputOutput“)simulators.tellAll(sendMessages)simulators.tellAll(DeltFunc“)CoupledSimulator1 CoupledSimulator2 Atomic1Atomic2putMessageputMyMessageCoupled1sendDownMessageSimulate hierarchical coupled model in real time mode- decentralized wayRTCoordinatorRTCoupledCoordinator CoupledRTSimulator4 Atomic4CoupledRTSimulator3 Atomic3putMessageputMessageputMessageCoupledRTSimulator1 CoupledRTSimulator2 Atomic1Atomic2putMessageputMyMessageCoupled1sendDownMessagesimulators.tellAll(initialize“)simulators.tellAll(simulate“)simulators.tellAll(stopSimulate)Relationship between models and simulatorscoordinator coupledCoordinator1 coupledSimulator4 Atomic4coupledSimulator3 Atomic3coupledSimulator1 coupledSimulator2 Atomic1Atomic2Coupled1CoupledDistributed SimulationRTCoordinatorServerSimulatorProxy1SimulatorProxy3SimulatorProxy2coupledRTSimulator1coupledRTSimulator2RTCoordinatorClient1RTCoupledSimulatorClient2RTCoupledSimulatorClient3Atomic4Atomic3Coupled1Atomic1Atomic2CoupledDistributed SimulationCoordinatorServerSimulatorProxy1SimulatorProxy3SimulatorProxy2coupledSimulator1coupledSimulator2CoordinatorClient1CoupledSimulatorClient2CoupledSimulatorClient3Atomic4Atomic3Coupled1Atomic1Atomic2Coupled