scholarly journals Effective impedance over ordered fields

2021 ◽  
Vol 62 (3) ◽  
pp. 033502
Author(s):  
Anna Muranova
Keyword(s):  
Ordered Fields ◽  
Effective Impedance

Effective Impedance of a Statistically Rough Surface: Numerical Analysis

1997 ◽  
Vol 51 (2-3) ◽  
pp. 119-132
Author(s):  
V. F. Naumenko ◽  
Leonid Aleksandrovich Pazynin ◽  
A. S. Bryukhovetsky
Keyword(s):  
Numerical Analysis ◽  
Rough Surface ◽  
Effective Impedance

Effective impedance model for analysis of reflection at the interfaces of photonic crystals

2007 ◽  
Vol 32 (7) ◽  
pp. 778 ◽  
Author(s):  
Babak Momeni ◽  
Ali Asghar Eftekhar ◽  
Ali Adibi
Keyword(s):  
Photonic Crystals ◽  
Impedance Model ◽  
Effective Impedance

On the validity of hilbert's nullstellensatz, artin's theorem, and related results in grothendieck toposes

1988 ◽  
Vol 53 (4) ◽  
pp. 1177-1187
Author(s):  
W. A. MacCaull
Keyword(s):  
Intuitionistic Logic ◽  
Main Idea ◽  
Rational Functions ◽  
Completeness Theorem ◽  
Point Of View ◽  
Polynomial Rings ◽  
Von Neumann ◽  
Ordered Fields ◽  
Von Neumann Regular ◽  
Theoretic Point

Using formally intuitionistic logic coupled with infinitary logic and the completeness theorem for coherent logic, we establish the validity, in Grothendieck toposes, of a number of well-known, classically valid theorems about fields and ordered fields. Classically, these theorems have proofs by contradiction and most involve higher order notions. Here, the theorems are each given a first-order formulation, and this form of the theorem is then deduced using coherent or formally intuitionistic logic. This immediately implies their validity in arbitrary Grothendieck toposes. The main idea throughout is to use coherent theories and, whenever possible, find coherent formulations of formulas which then allow us to call upon the completeness theorem of coherent logic. In one place, the positive model-completeness of the relevant theory is used to find the necessary coherent formulas.The theorems here deal with polynomials or rational functions (in s indeterminates) over fields. A polynomial over a field can, of course, be represented by a finite string of field elements, and a rational function can be represented by a pair of strings of field elements. We chose the approach whereby results on polynomial rings are reduced to results about the base field, because the theory of polynomial rings in s indeterminates over fields, although coherent, is less desirable from a model-theoretic point of view. Ultimately we are interested in the models.This research was originally motivated by the works of Saracino and Weispfenning [SW], van den Dries [Dr], and Bunge [Bu], each of whom generalized some theorems from algebraic geometry or ordered fields to (commutative, von Neumann) regular rings (with unity).

scholarly journals Ordered fields dense in their real closure and definable convex valuations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lothar Sebastian Krapp ◽  
Salma Kuhlmann ◽  
Gabriel Lehéricy
Keyword(s):  
Ordered Fields ◽  
Real Closure

Abstract In this paper, we undertake a systematic model- and valuation-theoretic study of the class of ordered fields which are dense in their real closure. We apply this study to determine definable henselian valuations on ordered fields, in the language of ordered rings. In light of our results, we re-examine the Shelah–Hasson Conjecture (specialized to ordered fields) and provide an example limiting its valuation-theoretic conclusions.

scholarly journals Effective Impedance of Magnetically Insulated Transmission Lines with Geometrical Discontinuity

2000 ◽  
Vol 120 (2) ◽  
pp. 218-224
Author(s):  
Kazuki Hiraoka ◽  
Mitsuo Nakajima ◽  
Makoto Shiho ◽  
Kazuhiko Horioka
Keyword(s):  
Transmission Lines ◽  
Effective Impedance ◽  
Geometrical Discontinuity

scholarly journals Ordered fields satisfying Rolle's theorem

1986 ◽  
Vol 30 (1) ◽  
pp. 66-78 ◽  
Author(s):  
Ron Brown ◽  
Thomas C. Craven ◽  
M.J. Pelling
Keyword(s):  
Rolle’S Theorem ◽  
Ordered Fields

scholarly journals A Broadband Ultrathin Nonlinear Switching Metamaterial

2017 ◽  
Vol 6 (2) ◽  
pp. 64
Author(s):  
E. Zarnousheh Farahani ◽  
S. Jarchi ◽  
A. Keshtkar
Keyword(s):  
Incident Wave ◽  
Optimization Method ◽  
Resonant Mode ◽  
Unit Cell ◽  
Incident Power ◽  
Full Wave ◽  
Effective Impedance ◽  
Nonlinear Simulations ◽  
Switching Property ◽  
Transmission And Reflection

In this paper, an ultrathin planar nonlinear metamaterial slab is designed and simulated. Nonlinearity is provided through placing diodes in each metamaterial unit cell. The diodes are auto-biased and activated by an incident wave. The proposed structure represents a broadband switching property between two transmission and reflection states depending on the intensity of the incident wave. High permittivity values are presented creating a near zero effective impedance at low power states, around the second resonant mode of the structure unit cell; as the result, the incident wave is reflected. Increasing the incident power to the level which can activate the loaded diodes in the structure results in elimination of the resonance and consequently a drop in the permittivity values near the permeability one as well as a switch to the transmission state. A full wave as well as a nonlinear simulations are performed. An optimization method based on weed colonization is applied to the unit cell of the metamaterial slab to achieve the maximum switching bandwidth. The structure represents a 24% switching bandwidth of a 10 dB reduction in the reflection coefficient.

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