Forecasting of ionospheric critical frequency using neural networks

Multilayer perceptron type neural networks (NN) are employed for forecasting ionospheric critical frequency (foF2) one hour in advance. The nonlinear black-box modeling approach in system identification is used. The main contributions: 1. A flexible and easily accessible training database capable of handling extensive physical data is prepared, 2. Novel NN design and experimentation software is developed, 3. A training strategy is adopted in order to significantly enhance the generalization or extrapolation ability of NNs, 4. A method is developed for determining the relative significances (RS) of NN inputs in terms of mapping capability

A Neural Network for Spatial and Temporal Modeling of foF2 Data Based on Satellite Measurements

Part 6: Classification Pattern RecognitionInternational audienceThis paper presents the application of Neural Networks for the spatial and temporal modeling of (critical frequency) foF2 data over Europe. foF2 is the most important parameter in describing the electron density profile of the ionosphere since it represents the critical point of maximum electron density in the profile and therefore can be used to drive empirical models of electron density which incorporate foF2 as an anchor point in the profile shape. The model is based on radio occultation (RO) measurements by LEO (Low Earth Orbit) satellites which provide excellent spatial coverage of foF2 measurements

Female Autonomy, Social Norms and Intimate Partner Violence against Women in Turkey

<p>The theoretical literature asserts that intimate partner violence against women stems from inequalities within the relationship, and it strengthens both male power and control, and female subordination. Using Structural Equation Modelling, this paper addresses the two-way relationship between intimate partner violence and female autonomy in Turkey. Consistent with the theory, we find that (1) violence has a significant and negative effect on female autonomy; and (2) the incidence of violence decreases with the level of female autonomy. We also find that intimate partner violence is an increasing function of the strength of men’s commitment to social norms upholding traditional gender roles.</p