Three-Dimensional Electromagnetic Approach to the Modeling of Time Reversal Technique for Communication

2007 ◽  
Author(s):  
A. Khaleghi ◽  
G. El Zein
Keyword(s):  
Time Reversal ◽  
Three Dimensional

Imaging Cracks in Bones Using Acoustic Nonlinearity: A Simulation Study

2011 ◽  
Vol 97 (5) ◽  
pp. 728-733
Author(s):  
Yang Liu ◽  
Xiasheng Guo ◽  
Zhao Da ◽  
Dong Zhang ◽  
Xiufen Gong
Keyword(s):  
Time Reversal ◽  
Three Dimensional ◽  
Harmonic Component ◽  
Ultrasonic Signal ◽  
Long Bone ◽  
Third Harmonic ◽  
Acoustic Nonlinearity ◽  
The Third ◽  
Nonlinear Approach ◽  
Radial Depth

This article proposes an acoustic nonlinear approach combined with the time reversal technique to image cracks in long bones. In this method, the scattered ultrasound generated from the crack is recorded, and the third harmonic nonlinear component of the ultrasonic signal is used to reconstruct an image of the crack by the time reversal process. Numerical simulations are performed to examine the validity of this approach. The fatigue long bone is modeled as a hollow cylinder with a crack of 1, 0.1, and 0.225 mm in axial, radial and circumferential directions respectively. A broadband 500 kHz ultrasonic signal is used as the exciting signal, and the extended three-dimensional Preisach-Mayergoyz model is used to describe the nonclassical nonlinear dynamics of the crack. Time reversal is carried out by using the filtered third harmonic component. The localization capability depends on the radial depth of the crack.

Three-Dimensional Lightning Positioning in Low-Frequency Band Using Time Reversal in Frequency Domain

2020 ◽  
Vol 62 (3) ◽  
pp. 774-784 ◽  
Author(s):  
Bo Liu ◽  
Li-Hua Shi ◽  
Shi Qiu ◽  
Heng-Yi Liu ◽  
Zheng Sun ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Frequency Band ◽  
Time Reversal ◽  
Three Dimensional ◽  
Low Frequency

Three dimensional time reversal optical tomography

2011 ◽  
Author(s):  
Binlin Wu ◽  
W. Cai ◽  
M. Alrubaiee ◽  
M. Xu ◽  
S. K. Gayen
Keyword(s):  
Time Reversal ◽  
Optical Tomography ◽  
Three Dimensional

scholarly journals Exceptional Chern-Simons-Matter dualities

2019 ◽  
Vol 7 (4) ◽  
Author(s):  
Clay Cordova ◽  
Po-Shen Hsin ◽  
Kantaro Ohmori
Keyword(s):  
Gauge Theory ◽  
Topological Field Theories ◽  
Time Reversal ◽  
Three Dimensional ◽  
Field Theories ◽  
Chiral Algebra ◽  
Gauge Groups ◽  
Topological Field ◽  
Conformal Embeddings ◽  
Chern Simons

We use conformal embeddings involving exceptional affine Kac-Moody algebras to derive new dualities of three-dimensional topological field theories. These generalize the familiar level-rank duality of Chern-Simons theories based on classical gauge groups to the setting of exceptional gauge groups. For instance, one duality sequence we discuss is (E_{N})_{1}\leftrightarrow SU(9-N)_{-1}(EN)1↔SU(9−N)−1. Others such as SO(3)_{8}\leftrightarrow PSU(3)_{-6},SO(3)8↔PSU(3)−6, are dualities among theories with classical gauge groups that arise due to their embedding into an exceptional chiral algebra. We apply these equivalences between topological field theories to conjecture new boson-boson Chern-Simons-matter dualities. We also use them to determine candidate phase diagrams of time-reversal invariant G_{2}G2 gauge theory coupled to either an adjoint fermion, or two fundamental fermions.

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