NUMERICAL CHARACTERIZATION MODEL OF VECTOR HYSTERESIS FOR MAGNETIC MATERIALS
The paper presents a numerical method based on Preisach model for the characterization and modelling of hysteretic magnetic materials exhibiting vector hysteresis, with acceptable accuracy, based on minimal material measurement data. The identification approach based on the Everett distribution function is a way to obtain accurate numerical solutions when the experimental data of the magnetic material are scarce, for instance: there are known only the initial magnetization curve and the upward major branch for two directions (rolling and transverse ones). The comparison between the measured and simulated major loop curves for another magnetization direction shows good agreements.
A Preisach-Stoner-Wohlfarth Vector Model
In previous papers we presented a new model of vector hysteresis, called RVM. The crux of the model is the definition of a vector hysteron, described in the H-space, and limited by a closed critical surface. Generally, the critical surface may be any closed simply connected surface, such that each surface point has a unique surface normal. The magnetization computed should be a conservative function of the applied field, and constant in magnitude. This paper proposes a new model, called the PSW vector model, for the magnetization outside the critical surface. It is a generalization of the RVM based upon the merging of the vector Preisach model and the Stoner-Wohlfarth model.
Health-care practices of the rural aged.
1. One of the primary concerns of the rural aged is the maintenance of their physical health so that they may function independently and remain in their own homes. 2. The findings of this study indicate that most older rural adults do not regularly have positive health-care practices. This may be due to the unavailability of health-care providers or health promotion programs in isolated rural areas. 3. Implications of this study include the need to make health promotion programs relevant to the concerns of the rural aged rather than those of the urban elderly.