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Mitchell, E. Eugene; Olsen, Charles F.
doi: 10.1177/003754977502500501pmid: N/A
This paper describes three algorithms for the digital computation of the frequency response of linear sys tems and discusses their advantages and disadvantages.The third method presented is a novel one which applies the standard polynominal quadratic synthetic division algorithm in a unique way to the problem. The method allows the forward and feedback-path transfer functions to be inputted in any form; it computes the open-loop and closed-loop frequency responses in one pass; and, most importantly, it does not require numerical factoring at any point. The method is easy to use and appears to run effi ciently, particularly for high-order systems. The paper concludes with FORTRAN and BASIC programs which implement the algorithm of Method Three.
Kwak, N.K.; Kuzdrall, Paul J.; Schmitz, Homer H.
doi: 10.1177/003754977502500502pmid: N/A
This paper describes a simulation procedure for determining the number of patients that the recovery room must accommodate in a hospital with a given number of operating rooms. The particular case simu- Zated was that of Deaconess Hospital in Saint Louis, which has 505 beds and 5 operating rooms. The statistics on the use of the operating rooms and the recovery room were collected from hospital records and incorporated in the simulation. They take into account the types of surgery performed, the number of patients receiving each type of surgical treatment, the patients' need for the recovery room, and the length of time patients need to stay in the recovery room (a statistical function of the type of surgery).The simulation uses Monte Carlo techniques. Its results closely duplicated the hospital's experience and were accepted by management as the basis for deciding the capacity of the recovery room that would be required after the hospital expanded its facilities. It was found that with 5 operating rooms this hospital required a recovery room with a capacity for 13 patients. The simulation is a general one that can be applied to other hospitals.This paper includes the principal results of the simulation of the operation of the Deaconess Hospital's surgical suite as it affects the number of patients served by the recovery room.
doi: 10.1177/003754977502500503pmid: N/A
Ferromagnetic hysteretic behavior is a particularly complex phenomenon; it can actually be construed as the response of a large-scale system consisting of interacting magnetic domains. The problem of simula tion of systems containing one or more ferromagnetic devices is correspondingly very difficult. Classical modeling attempts have suffered on the one hand from complex mathematics unsuited for practical implemen tation and on the other from simplistic models that retain no connection with underlying physical processes. The model developed in this paper is of a phenomenological nature; yet it bears rather close correspondence on an energy-exchange level with the physics of ferromagnetism. The basic mathematical model has the nature of a mechanical analog that possesses the same qualitative features as ferro magnetic material. It is a planar representation on which a systems-theoretic state-space analysis is performed. A method for estimation of the model parameters is outlined, and simulation results are compared with experimental data for an iron-core toroid.
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