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
Discrete vs. Continuous Simulation: When Does It Matter? 1
number of customers in the system increases. The system is modeled using discrete event and continuous simulation. The results of two simulations are compared with each other and with their analytical solutions. In the second part, the number of customers in the system affects the arrival rate first with a continuous information delay, then with a discrete delay. Discrete and continuous simulations give very similar results in terms of dynamic behaviors of system variables. There are some minor differences in terms of the steady-state values of the variables, particularly the average time spent in system. Finally, increasing proportionately all parameters of the system (arrival rate and number of servers), reduces the discreteness of the system, bringing the discrete and continuous simulation results much closer.
Phase formation during mechanical alloying in the Ti–Si system
Abstract Mechanical alloying of Ti–Si powder mixture or TiH 1.924 –Si powder mixture was performed by high-energy ball milling, in which the Ti to Si mole ratio was 1:2. The phase formations in both mixtures during milling were investigated by X-ray diffraction. Mechanical alloying a mixture of elemental powders led to the formation of TiSi 2 equilibrium compound, while when starting from Si + TiH 1.924 , a metastable phase was formed. The metastable phase completely transforms to TiSi 2 when the mechanically alloyed powder is annealed at temperatures above 800 °C. Two different pathways of phase transitions during mechanical alloying are attributed to the existence of hydrogen atoms, i.e., when starting from Si + TiH 1.924 compared to Si + Ti, the kinetics for the formation of the TiSi 2 intermetallic compound slows down. The kinetics related to the different phase transitions depending on the starting powder mixture are discussed.