Discrete Event Simulation Technique

Prototyping is typically the precursor to a product pilot, while discrete event simulation (Technique 41) can be conducted before or instead oi a service pilot. 

In nonlinear chromatography, each adsorption site should be labeled and continuously monitored since the behavior of the molecule will depend on the presence of other molecules. The discrete event simulation technique which processes a list of events ordered along the time axis can be used for the simulation of this process. This technique is illustrated in Figure 14.24. 

The Clock It is essential in the simulation to keep the track of time and record the timestamp of events. The principal difference between realtime and discrete-events simulation techniques is that in continuous simulation the timestamp advances by a fixed amount at each stage of the simulation and the new state of the system is... 

Typically, a flow network as a representation of the production system and its components combined with Monte Carlo simulation utilizing the discrete event simulation technique is used to generate the results of a RAM analysis. 

If physical experiments are not feasible or cost-effective, use a computer simulation such as discrete event simulation (see Technique 41) to determine which inputs result in the optimal output. 

It may take several iterations before you get the model just right, especially if you re new to this technique. Don t give up Once you get the hang of it, you ll find that discrete event simulation can be an invaluable approach. 

Discrete-event simulation is probably the most flexible simulation technique. Flows are here discretely modelled, i.e. at a discrete number of time indices flows are controlled. Processors can represent various system elements depending on the type of flows controlled and the processors internal decision rules. Processors of material flows represent e.g. production facilities where flows are transformed and (possibly) delayed to reflect the time consumption for production. Moreover, processors may also reflect transport or storage facilities where flows are controlled depending on the available capacities. 

A number of quantitative analysis techniques have been presented in literature for FMS analysis (Matta and Semeraro 2005) and Groover (2007). FMS analysis techniques include deterministic and queuing models, discrete events simulation, and other approaches including heuristics. 

An alternative proposed in previous works (for example, Bdrard et al 2(X)0) consists in coupling a Discrete Event Simulator (DES) (in order to evaluate the feasibility of the production at medium term scheduling) with a master optimization procedure generally based on stochastic techniques such as GA (to take into account the combinatorial feature due to the large number of discrete variables in the optimization problem). These ideas... 

Particle-based simulation techniques include atomistic MD and coarse-grained molecular dynamics (CG-MD). Accelerated dynamics methods, such as hyperdynamics and replica exchange molecular dynamics (REMD), are very promising for circumventing the timescale problem characteristic of atomistic simulations. Structure and dynamics at the mesoscale level can be described within the framework of coarse-grained particle-based models using such methods as stochastic dynamics (SD), dissipative particle dynamics (DPD), smoothed-particle hydrodynamics (SPH), lattice molecular dynamics (LMD), lattice Boltzmann method (IBM), multiparticle collision dynamics (MPCD), and event-driven molecular dynamics (EDMD), also referred to as collision-driven molecular dynamics or discrete molecular dynamics (DMD). 

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