SIMULATION: Transactions of The Society for Modeling and Simulation International

doi: 10.1177/003754977502500601pmid: N/A

McLeod, John; McLeod, Suzette

doi: 10.1177/003754977502500606pmid: N/A

Halfon, Efraim

doi: 10.1177/003754977502500604pmid: N/A

Montgomery, Douglas C.; Evans, Daniel M.

doi: 10.1177/003754977502500602pmid: N/A

Computer simulation models are frequently used to determine the combination of levels for a set of independent variables at which a response variable is optimized. This process leads to problems of experi mental design, i.e., the choice of levels of the independent variables at which the simulation model is to be run and at which the model's responses are to be observed. This paper considers second-order response-surface designs and optimization procedures for use in this situation. Several classes of designs are constructed and applied to surfaces typically generated by computer simulation models. Results are obtained which should assist in the selection of de signs in general or for use on specific surfaces. An application of second-order response-surface de signs to a digital simulator of a street network is presented; the object is to find optimal settings for the traffic signals during the morning peak of traffic flow.

Højberg, K. Søe

doi: 10.1177/003754977502500603pmid: N/A

HAPS (Hybrid Analog Programming System) is an analog compiler that can be run on a minicomputer in an interactive mode. Essentially HAPS is written in FORTRAN. The equations to be programmed for an ana log computer are read in by using a FORTRAN-like notation. The input must contain maximum and minimum values for the variables. The output file includes potentiometer coefficients and static-test 'measuring values.' The file format is fitted to an automatic potentiometer-setting and static-test program. Patch instructions are printed by HAPS.The article describes the principles of HAPS and emphasizes the limitations HAPS puts on equation structure, types of computing circuit, scaling, and static testing.

Hay, John L.; Chaplin, Robert I.

doi: 10.1177/003754977502500605pmid: N/A

A model is presented which produces the locus on the B-H plane of a ferromagnetic specimen subject to dynamic operating conditions. The model accurately represents the magnetisation curve and the saturation Zoop as well as exhibiting the correct inner loop behaviour. The concept of a primitive magnetic eZe ment is introduced, and the paper illustrates how a finite number of these elements may be combined and their characteristics chosen so as to represent the hysteretic behaviour of a ferromagnetic device. Validation is achieved by comparing experimental and computed results for both symmetrical and asymmetri caZ inner Zoop behaviour. The incremental inductance of an electro-magnetic device may be readily calculat ed from the proposed model which is presented in a form suitable for either digital or analog computer simulation.