SIMULATIONS-OVERVIEW OF HYBRID SIMULATION MODELS
MSc Bojan Jovanovski * Ss. Cyril and Methodi University, Faculty of Mecahical Engineering, Skopje, Macedonia Dr Robert Minovski Ss. Cyril and Methodi University, Faculty of Mecahical Engineering, Skopje, Macedonia Dr Siegfried Voessner Institute of Engineering and Business Informatics, TU Graz, Austria Dr Gerald Lichtenegger Institute of Engineering and Business Informatics, TU Graz, Austria doi:10.5937/jaes10-2512
A methodology for Integrating and Synchronizing the System Dynamics and Discrete Event Simulation Paradigms
With the adoption of integration and system perspectives in managing the manufacturing systems and the pressure imposed by the increased competition and rapidly changing business environment, the need has arisen for new approaches for simulating the manufacturing enterprise. We have proposed SDDES; a hybrid System Dynamics Discrete Event Simulation approach to simulating the integrated manufacturing enterprise. SDDES offers comprehensive simulation models that encompass all management levels and recognize the differences between them in terms of scope and frequency of decision making as well as the levels of details preferred and used at each level. SDDES maintains the integrity of the two simulation paradigms and can use existing/legacy simulation models without requiring learning new simulation skills. In this paper we describe the modular structure of SDDES, our method to synchronize and coordinate SD and DES, and the functional model of the SDDES controller, which manages the integration of the two simulation methodologies.
Coated-wire electrodes containing polymer immobilized ionophores blended with poly(vinyl chloride).
Polymers containing covalently attached 18-crown-6 or 2.2.2 cryptand units were incorporated into plasticized PVC membranes and the composite membranes were examined as potassium ion sensor elements. Ionophores were linked to carboxy-PVC and to poly(acrylic acid) via amide linkages to an alkyl spacer unit. Coated-wire electrodes (CWEs) from the immobilized ionophores gave acceptable responses, but conventional ion-selective membrane electrodes (ISEs) prepared by solvent casting were inactive. Dip-cast membranes did give active ISEs. Potassium electrode performance was independent of the loading of the ionophore within the acrylate support polymer, but depended upon the spacer length. Ion selectivity varied with the ionophore loading within the support polymer. Selectivity is a composite of the ionophore selectivity and ion-exchange interactions with the acrylate backbone, giving selectivities akin to carboxylate substituted crown ethers, notably enhanced monovalent/divalent ion discrimination relative to the ionophore in solution. Polymer immobilization extended the lifetime of active electrodes.