Two-Dimensional Terahertz-Infrared-Visible Spectroscopy Elucidates Coupling Between Low- and High-Frequency Modes

2019 ◽  
pp. 197-214
Author(s):  
Laura Vietze ◽  
Mischa Bonn ◽  
Maksim Grechko
Keyword(s):  
High Frequency ◽  
Two Dimensional ◽  
Visible Spectroscopy ◽  
High Frequency Modes

High-frequency modes in a two-dimensional rectangular room with windows

2010 ◽  
Vol 56 (4) ◽  
pp. 525-536 ◽  
Author(s):  
E. D. Shabalina ◽  
N. V. Shirgina ◽  
A. V. Shanin
Keyword(s):  
High Frequency ◽  
Two Dimensional ◽  
Rectangular Room ◽  
High Frequency Modes

Despeckling of Sar Images Using Shrinkage of Two-Dimensional Discrete Orthonormal S-Transform

2020 ◽  
pp. 2150023
Author(s):  
Priya R. Kamath ◽  
Kedarnath Senapati ◽  
P. Jidesh
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Relevant Information ◽  
Detection Algorithm ◽  
Two Dimensional ◽  
Sar Images ◽  
S Transform ◽  
Processing Step ◽  
Frequency Components ◽  
Shock Filter

Speckles are inherent to SAR. They hide and undermine several relevant information contained in the SAR images. In this paper, a despeckling algorithm using the shrinkage of two-dimensional discrete orthonormal S-transform (2D-DOST) coefficients in the transform domain along with shock filter is proposed. Also, an attempt has been made as a post-processing step to preserve the edges and other details while removing the speckle. The proposed strategy involves decomposing the SAR image into low and high-frequency components and processing them separately. A shock filter is used to smooth out the small variations in low-frequency components, and the high-frequency components are treated with a shrinkage of 2D-DOST coefficients. The edges, for enhancement, are detected using a ratio-based edge detection algorithm. The proposed method is tested, verified, and compared with some well-known models on C-band and X-band SAR images. A detailed experimental analysis is illustrated.

Discriminating intra-parasequence stratigraphic units from two-dimensional quantitative parameters

2021 ◽  
Vol 91 (8) ◽  
pp. 887-911
Author(s):  
Manuel F. Isla ◽  
Ernesto Schwarz ◽  
Gonzalo D. Veiga ◽  
Jerónimo J. Zuazo ◽  
Mariano N. Remirez
Keyword(s):  
High Frequency ◽  
Two Dimensional ◽  
Facies Associations ◽  
Different Types ◽  
Lateral Extent ◽  
Successive Wave ◽  
Shell Bed ◽  
Definition Of ◽  
High Resolution Sequence Stratigraphy ◽  
Bounding Surfaces

ABSTRACT The intra-parasequence scale is still relatively unexplored territory in high-resolution sequence stratigraphy. The analysis of internal genetic units of parasequences has commonly been simplified to the definition of bedsets. Such simplification is insufficient to cover the complexity involved in the building of individual parasequences. Different types of intra-parasequence units have been previously identified and characterized in successive wave-dominated shoreface–shelf parasequences in the Lower Cretaceous Pilmatué Member of the Agrio Formation in central Neuquén Basin. Sedimentary and stratigraphic attributes such as the number of intra-parasequence units, their thickness, the proportions of facies associations in the regressive interval, the lateral extent of bounding surfaces, the degree of deepening recorded across these boundaries, and the type and lateral extent of associated transgressive deposits are quantitatively analyzed in this paper. Based on the analysis of these quantified attributes, three different scales of genetic units in parasequences are identified. 1) Bedset complexes are 10–40 m thick, basin to upper-shoreface successions, bounded by 5 to 16 km-long surfaces with a degree of deepening of one to three facies belts. These stratigraphic units represent the highest hierarchy of intra-parasequence stratigraphic units, and the vertical stacking of two or three of them typically forms an individual parasequence. 2) Bedsets are 2–20 m thick, offshore to upper-shoreface successions, bounded by up to 10 km long surfaces with a degree of deepening of zero to one facies belt. Two or three bedsets stack vertically build a bedset complex. 3) Sub-bedsets are 0.5–5 m thick, offshore transition to upper-shoreface successions, bounded by 0.5 to 2 km long surfaces with a degree of deepening of zero to one facies belt. Two or three sub-bedsets commonly stack to form bedsets. The proposed methodology indicates that the combination of thickness with the proportion of facies associations in the regressive interval of stratigraphic units can be used to discriminate between bedsets and sub-bedsets, whereas for higher ranks (bedsets and bedset complexes) the degree of deepening, lateral extent of bounding surfaces, and the characteristics of associated shell-bed deposits become more effective. Finally, the results for the Pilmatué Member are compared with other ancient and Holocene examples to improve understanding of the high-frequency evolution of wave-dominated shoreface–shelf systems.

Shock Mitigation by Energy Reversal to the High Frequency Modes

2014 ◽  
Author(s):  
Mohammad A. AL-Shudeifat ◽  
Alexander F. Vakakis ◽  
Lawrence A. Bergman
Keyword(s):  
High Frequency ◽  
Large Scale ◽  
Computational Study ◽  
Dynamic Structure ◽  
Frequency Mode ◽  
Frame Structure ◽  
Shock Energy ◽  
Modal Damping ◽  
Shock Mitigation ◽  
High Frequency Modes

In this computational study, a light-weight dynamic device is investigated for passive energy reversal from the lowest frequency mode to the high frequency modes of a large-scale frame structure for rapid shock mitigation. The device is based on the single-sided vibro-impact mechanism. It has two functions for passive energy transfer: a nonlinear energy sink (NES) for local energy dissipation and an energy pump to high frequency modes where a significant amount of the shock energy is rapidly dissipated. As a result, a significant portion of the shock energy induced into the linear dynamic structure can be passively reversed from the lowest frequency mode to the high frequency modes and rapidly dissipated by their modal damping. The amount of the energy dissipated by the modal damping of the high frequency modes can be controlled by the amount of inherent damping in the device. Ideally, the device can passively reverse up to 80% of the input shock energy from the lowest frequency mode to the high frequency modes when its damping is assumed to be zero and its impact coefficient of restitution is equal to unity. The shock energy redistribution between this device and the high frequency modes is found to be efficient for rapid shock mitigation in the considered 9-story dynamic structure.

scholarly journals LDRD final report on Bloch Oscillations in two-dimensional nanostructure arrays for high frequency applications.

2008 ◽  
Author(s):  
Sungkwun Kenneth Lyo ◽  
Wei Pan ◽  
John Louis Reno ◽  
Joel Robert Wendt ◽  
Daniel Lee Barton
Keyword(s):  
High Frequency ◽  
Final Report ◽  
Two Dimensional ◽  
Bloch Oscillations ◽  
Nanostructure Arrays
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