Mass transfer in droplets determined by analog computationWellek, R.M.; Kuo, J.T.; Waggoner, R.C.
doi: 10.1177/003754977001500601pmid: N/A
A mechanism describing the rate of mass transfer to single droplets with a special type of internal circulation is described by a model consisting of a partial differential equation with two independent variables. A Sturm-Liouville system is obtained when the partial differential equation is transformed into a set of ordinary differential equations by the separation-of-variables technique. The eigenvalues and eigenfunctions which determine the solution to this system are obtained by a two variable search procedure on an iterative-analog computer.
The simulation of shot processesDaly, K.C.; Thomas, J.B.
doi: 10.1177/003754977001500602pmid: N/A
Shot processes may be used as models for a wide class of naturally occurring random processes ranging from non-Gaussian impulse processes to nearly Gaussian processes. This paper shows how shot processes with desired spectral properties may be simulated easily. Sev eral models are proposed for using shot processes as locally generated noise sources with statistical charac teristics which conform to many naturally occurring noise processes.More general models could be considered and the range of applicability can be extended beyond that men tioned in this paper. However, even the basic models treated can provide a much wider range of noise envi ronment than that usually considered in simulation tech niques.
Distributed system simulation using infinite product expansionsGoodson, R.E.
doi: 10.1177/003754977001500603pmid: N/A
Infinite product expansions for the transcendental terms in the transfer functions for linear distributed systems are developed. Simulation of the dynamic re sponse of such systems is indicated, using the product expansion. Comparisons are made between the classi cal eigenvalue and product expansion approximations. It is concluded that the product expansion is an ex tremum transient-amplitude-preserving approximation based on the correct characteristic roots.
The inverse modeling problemPatten, Bernard C.
doi: 10.1177/003754977001500604pmid: N/A
In simulation modeling of very large-scale systems, such as social and natural systems, reductions in scale must be so severe that state variables of the abstraction (model) often cannot be translated back to variables that have real-world significance. Model behavior may not much resemble anything that occurs naturally.If y is a real system and x a model of it, the two can be viewed as related by a set of homomorphic corres pondences M. Then, xMy means x "is a model of" y. Behavior of x pertains to that of y only as M is a valid model, and the relationship is implicit in an inverse model M-1, defined from the fact that xMy implies yM-1x (y "is modeled by" x). To make it explicit, that is to interpret model behavior in terms of real-world variables, means in some sense to be able to identify M-1. One approach to estimating it is suggested, but a definite solution is not reached.