scholarly journals Numerical comparison between the ‘‘channel model’’ and the ‘‘effective-electron model’’ descriptions of linear superexchange interactions in ionic solids

1986 ◽  
Vol 33 (6) ◽  
pp. 3672-3677 ◽  
Author(s):  
E. L. Bominaar ◽  
R. Block
Keyword(s):  
Channel Model ◽  
Numerical Comparison ◽  
Electron Model ◽  
Effective Electron ◽  
Ionic Solids

THE EFFECT OF THE ELECTRON CORRELATION ON THE ELECTRICAL RESISTIVITY OF LIQUID METALS

1963 ◽  
Vol 41 (9) ◽  
pp. 1397-1404
Author(s):  
Hirohisa Endo ◽  
Shota Suekane
Keyword(s):  
Electrical Resistivity ◽  
Liquid Metals ◽  
Elementary Theory ◽  
Mean Free Path ◽  
Liquid Sodium ◽  
Electron Model ◽  
Plasma Oscillations ◽  
Effective Electron ◽  
Conduction Electrons ◽  
Ion Interactions

An elementary theory of the electrical resistivity of monovalent liquid metals is given. On using the theory of the plasma oscillations of conduction electrons, the electron–ion interactions are separated into two parts: one gives the effective electron–ion interactions which are screened as the result of the effects of the plasma oscillations of the conduction electrons and contributes directly to the electrical resistivity; the other describes the interactions between the ions and the plasma oscillations. The screened electron–ion interaction is defined as the pseudo-potential of the ion.The theory constructed on the basis of the free-electron model is applied in the first instance to estimate the electrical resistivity of liquid sodium near the melting point. Callaway's potential and the correlation function of ions determined from neutron diffraction experiments are used and the mean free path of a conduction electron is calculated numerically. Therefore, in our theory, the "plasma term" and the "structure term" of Ziman's theory are not treated separately.

Exploring the Boundaries of the Number–Temporal Order Association

2015 ◽  
Vol 62 (3) ◽  
pp. 198-205 ◽  
Author(s):  
Dana Ganor-Stern
Keyword(s):  
Embodied Cognition ◽  
Mental Representation ◽  
Temporal Order ◽  
Past Research ◽  
Numerical Comparison ◽  
Negative Number ◽  
Comparison Task ◽  
Negative Numbers ◽  
The Past

Past research has shown that numbers are associated with order in time such that performance in a numerical comparison task is enhanced when number pairs appear in ascending order, when the larger number follows the smaller one. This was found in the past for the integers 1–9 ( Ben-Meir, Ganor-Stern, & Tzelgov, 2013 ; Müller & Schwarz, 2008 ). In the present study we explored whether the advantage for processing numbers in ascending order exists also for fractions and negative numbers. The results demonstrate this advantage for fraction pairs and for integer-fraction pairs. However, the opposite advantage for descending order was found for negative numbers and for positive-negative number pairs. These findings are interpreted in the context of embodied cognition approaches and current theories on the mental representation of fractions and negative numbers.

Comparison of Nonlinear Spatial Correlation Models by the Influence of the Data Augmentation to the Classification Risk

2002 ◽  
Vol 7 (1) ◽  
pp. 31-42
Author(s):  
J. Šaltytė ◽  
K. Dučinskas
Keyword(s):  
Spatial Correlation ◽  
Random Fields ◽  
Data Augmentation ◽  
Gaussian Random Fields ◽  
Classification Rule ◽  
Numerical Comparison ◽  
First Order ◽  
Bayesian Risk ◽  
Correlation Models

The Bayesian classification rule used for the classification of the observations of the (second-order) stationary Gaussian random fields with different means and common factorised covariance matrices is investigated. The influence of the observed data augmentation to the Bayesian risk is examined for three different nonlinear widely applicable spatial correlation models. The explicit expression of the Bayesian risk for the classification of augmented data is derived. Numerical comparison of these models by the variability of Bayesian risk in case of the first-order neighbourhood scheme is performed.

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