Double-thin-shell approach to deriving total electron content from GNSS signals and implications for ionospheric dynamics near the magnetic equator

A new technique was developed to estimate the ionospheric total electron content (TEC) from Global Navigation Satellite System (GNSS) satellite signals. The vertically distributed electron density was parameterized by two thin-shell layers (double-shell approach). The spatiotemporal variation of TEC (strictly speaking, partial electron content) associated with each shell was approximated by the functional fitting of spherical surface harmonics. The major improvements over the conventional single-shell approach were as follows: (1) the precise estimation of TEC was achieved; (2) the estimated TEC was less dependent on the choice of shell heights; and (3) the equatorial anomaly was captured more correctly. Furthermore, higher and lower shells exhibited a different pattern of local time vs latitude variation, providing information on the ionosphere–thermosphere dynamics.

Ego and Self in Gestalt Theory

Summary The paper presents basic Gestalt theoretical concepts of ego and self. They differ from other concepts in the way that they do not comprehend ego and self as fixed entities or as central controlling instances of the psyche, but as one specific organized unit in a psychological field in dynamic interrelation with the other organized units—the environment units—of this field. On this theme, well-known representatives of Gestalt theory have presented some general and special theories since the early days of this approach that could partly be substantiated experimentally. They illuminate the relationship between ego and world in everyday life as well as in the case of mental disorders. Not only the spatial extension of the phenomenal ego is subject to situational changes, but also its place in the world, its functional fitting in this world, its internal differentiation, its permeability to the environment, and much more. The German Gestalt psychologist Wolfgang Metzger emphasizes the significant functional role that this dynamic plasticity of the phenomenal world and its continuously changing segregation of ego and environment have for human life by designating the phenomenal world as a “Central Steering Mechanism.” In this article, ego and self as part of this field in their interrelation with the total psychological field will be illuminated from the perspective of the thinking of the Gestalt psychologists Max Wertheimer, Kurt Koffka, Wolfgang Köhler, Kurt Lewin, Wolfgang Metzger, Mary Henle, Edwin Rausch, and Giuseppe Galli.

Double-thin-shell Approach to Deriving Total Electron Content From GNSS Signals and Implications for Ionospheric Dynamics Near the Magnetic Equator

A new technique was developed to estimate the ionospheric total electron content (TEC) from Global Navigation Satellite System (GNSS) satellite signals. The vertically distributed electron density was parameterized by two thin-shell layers (double-shell approach). The spatiotemporal variation of TEC (strictly speaking, partial electron content) associated with each shell was approximated by the functional fitting of spherical surface harmonics. The major improvements over the conventional single-shell approach were as follows: (1) the precise estimation of TEC was achieved; (2) the estimated TEC was less dependent on the choice of shell height; and (3) the equatorial anomaly was captured more correctly. Furthermore, higher and lower shells exhibited a different pattern of local time vs latitude variation, providing information on the ionosphere--thermosphere dynamics.

Evaluation of the Solar Quiet Reference Field (SQRF) Model for Space Weather Applications in the South America Magnetic Anomaly

In the present work, we evaluate the accuracy of the Solar Quiet Reference Field (SQRF) model for forecasting and predicting the geomagnetic solar quiet (Sq) daily field variation in the South America Magnetic Anomaly (SAMA) region. The model simulates the monthly average horizontal field of the geomagnetic quiet (Sq-H) daily variation solving a set of functional fitting equations for the specified geographic coordinates. We carried out two comparisons between the simulated and observational data of the Sq-H field. The first part attempts to evaluate the accuracy for predicting the Sq-H field over Medianeira (25.30°S, 54.11°W, dip angle: -33.45°) by using linear interpolation on the SQRF coefficients. The second part of the analysis attempts to evaluate the accuracy for forecasting the quiet daily field variation over Cachoeira Paulista (22.70°S, 45.01°W, dip angle: -38.48°). The results of the simulation for both locations show that this empirical model presents a good agreement with the Sq-H field obtained from the magnetic field data. The accuracy of the SQRF model (high correlation, r>0.9) provides a high potential for estimating and forecasting geomagnetic quiet daily field variation for space weather applications. Therefore, this model could be useful in the Sq-H field regions near of SAMA.

Ensemble of Regression-Type and Interpolation-Type Metamodels

Metamodels have become increasingly popular in the field of energy sources because of their significant advantages in reducing the computational cost of time-consuming tasks. Lacking the prior knowledge of actual physical systems, it may be difficult to find an appropriate metamodel in advance for a new task. A favorite way of overcoming this difficulty is to construct an ensemble metamodel by assembling two or more individual metamodels. Motivated by the existing works, a novel metamodeling approach for building the ensemble metamodels is proposed in this paper. By thoroughly exploring the characteristics of regression-type and interpolation-type metamodels, some useful information is extracted from the feedback of the regression-type metamodels to further improve the functional fitting capability of the ensemble metamodels. Four types of ensemble metamodels were constructed by choosing four individual metamodels. Common benchmark problems are chosen to compare the performance of the individual and ensemble metamodels. The results show that the proposed metamodeling approach reduces the risk of selecting the worst individual metamodel and improves the accuracy of the used individual metamodels.

Study on the Forecast Model of Water Quantity on the Basis of BP Artificial Neural Network

Back Propagation network, Widely used in automatic control, image recognition, hydrological forecasting and water quality evaluation, etc., as one of the Artificial Neural Networks, has stronger property of mapping, classification, functional fitting. This article takes the water flow of Lanzhou section of Yellow river as example by use of BP model to predict the water flow. It is well proved that BP network model can reach the purposes of early warning and forecasting.