Direct and Reverberant Field Amplitude Distributions in Nearly Hard Rooms

1961 ◽  
Vol 33 (12) ◽  
pp. 1699-1704 ◽  
Author(s):  
Richard H. Lyon
Keyword(s):  
Field Amplitude ◽  
Reverberant Field

On: “Effect of temporal and spatial variations of the primary signal on VLF total‐field surveys” by M. A. Vallee, M. Chouteau, and G. J. Palacky (January 1992 GEOPHYSICS, p. 97‐105)

Geophysics ◽  
1993 ◽  
Vol 58 (5) ◽  
pp. 756-756 ◽  
Author(s):  
Jean Roy
Keyword(s):  
Numerical Modeling ◽  
Field Amplitude ◽  
Primary Field ◽  
Dense Network ◽  
Total Field ◽  
Field Surveys ◽  
Attitude Stability ◽  
Amplitude Data ◽  
Primary Signal ◽  
Temporal And Spatial

Vallee et al. (1992) remark on the sensitivity of airborne ratio measuring VLF instruments to platform attitude stability. The authors also remind the users of VLF total field amplitude data, as produced by instruments such as the Herz TOTEM, of two problems associated with this type of data: spatial and temporal fluctuations of the VLF primary field. They recommend the use of a dense network of VLF monitoring stations and numerical modeling of field propagation to cope with these problems. These two recommendations are briefly discussed here and one alternative recommendation is made.

SQUEEZING AND PHOTON STATISTICS IN FIVE-WAVE MIXING PROCESS

2009 ◽  
Vol 23 (22) ◽  
pp. 2681-2693 ◽  
Author(s):  
SUNIL RANI ◽  
JAWAHAR LAL ◽  
NAFA SINGH
Keyword(s):  
Fundamental Mode ◽  
Coupling Parameter ◽  
Photon Number ◽  
Field Amplitude ◽  
Photon Statistics ◽  
Squeezed States ◽  
Wave Mixing ◽  
Quantum Field ◽  
Mixing Process ◽  
Signal Photon

We investigate theoretically the generation of squeezed states in spontaneous and stimulated five-wave mixing process. It has been found that squeezing occurs in field amplitude, amplitude-squared, amplitude-cubed and fourth-order amplitude states of the fundamental mode in the process. It is found to be dependent on coupling parameter g and phase values of the field amplitude of the fundamental mode. The process involves the absorption of two pump photons each having frequency ω1, emission of two probe photons of same frequency ω2 and a signal photon of frequency ω3. It is shown that squeezing is greater in a stimulated interaction than the corresponding squeezing in the spontaneous process. It is found that the degree of squeezing depends on the photon number in the first and higher orders. We study the statistical behaviour of quantum field in the fundamental mode. It has been found that the field shows sub-Poissonian behavior in this mode.

Determination of the space-charge field amplitude in polymeric photorefractive polymers

2005 ◽  
Vol 123 (24) ◽  
pp. 244905 ◽  
Author(s):  
Ui-Jung Hwang ◽  
Chil-Sung Choi ◽  
Nguyen Quoc Vuong ◽  
Nakjoong Kim
Keyword(s):  
Space Charge ◽  
Field Amplitude ◽  
Space Charge Field ◽  
Photorefractive Polymers ◽  
Charge Field

Scaling Behavior of Dynamic Hysteresis in Hard PZT Bulk Ceramics under Influence of Compressive Stress

2008 ◽  
Vol 55-57 ◽  
pp. 281-284 ◽  
Author(s):  
N. Wongdamnern ◽  
Athipong Ngamjarurojana ◽  
Supon Ananta ◽  
Yongyut Laosiritaworn ◽  
Rattikorn Yimnirun
Keyword(s):  
Energy Dissipation ◽  
Electric Field ◽  
Mechanical Stress ◽  
Compressive Stress ◽  
Power Law ◽  
Field Amplitude ◽  
Electric Field Amplitude ◽  
Bulk Ceramic ◽  
Compressive Stresses ◽  
The Difference

Effects of electric field-amplitude and mechanical stress on hysteresis area were investigated in partially depoled hard PZT bulk ceramic. At any compressive stress, the hysteresis area was found to depend on the field-amplitude with a same set of exponents to the power-law scaling. Consequently, inclusion of compressive stresses into the power-law was also obtained in the form of < A – Aσ=0 > α E05.1σ1.19 which indicated the difference of the energy dissipation between the under-stress and stress-free conditions.

Average Q and yield estimates from the Pahute Mesa test site

1987 ◽  
Vol 77 (4) ◽  
pp. 1274-1294
Author(s):  
R. W. Burger ◽  
T. Lay ◽  
L. J. Burdick
Keyword(s):  
Time Domain ◽  
Near Field ◽  
Energy Levels ◽  
Source Model ◽  
Spectral Shape ◽  
Field Amplitude ◽  
Far Field ◽  
Source Models ◽  
Attenuation Models ◽  
Shape Data

Abstract Attenuation models, with and without frequency dependence, have been developed through analysis of time-domain amplitude measurements and teleseismic spectral shape data from Pahute Mesa nuclear explosions. The time-domain analysis is based on a near-field to far-field amplitude comparison. The near-field amplitude information is incorporated in two parameterized explosion source models (Mueller-Murphy and Helmberger-Hadley) based on analyses of near-field data. The teleseismic amplitude observations are from a large data set of WWSSN short-period analog recordings. For the narrow-band time-domain data, the various source and attenuation models are indistinguishable. We utilize the spectral shape data in the 0.5- to 4-Hz band as a constraint on the source-attenuation models at higher frequencies, concluding that either source model, when convolved with the appropriate frequency-dependent Q model, can be consistent with both the near-field and far-field time-domain amplitudes and the spectral shape data. Given the trade-off between source and attenuation models and the similarity of the different source models in the 0.5- to 4-Hz band, it is difficult to prefer clearly one source model over the other. The Mueller-Murphy model is more consistent with surface wave amplitude measurements because of larger predicted long-period energy levels. Whether or not frequency dependence is included in the attenuation model, the value of t* near 1 Hz is about 1.0 sec (assuming the Mueller-Murphy source model) or 0.8 sec (assuming the Helmberger-Hadley source model). This 0.2 sec difference results from greater 1-Hz energy levels for the Mueller-Murphy source model. Adopting an average attenuation model, predicted amplitudes and yields are shown to be within the uncertainty of the data for all the events analyzed.

scholarly journals Sum Squeezing of the Field Amplitude in Frequency Upconversion Process

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Dilip Kumar Giri ◽  
Binod Kumar Choudhary
Keyword(s):  
Fundamental Mode ◽  
Higher Order ◽  
Sum Frequency Generation ◽  
Field Amplitude ◽  
Interaction Time ◽  
Squeezed States ◽  
Frequency Upconversion ◽  
Sum Frequency ◽  
Frequency Generation ◽  
Upconversion Process

Sum squeezing of the field amplitude is studied in the nondegenerate and degenerate frequency upconversion process under the short interaction time. It is shown that sum squeezing can be converted into normal squeezing via sum-frequency generation in the nondegenerate frequency upconversion process, while the amplitude-squared squeezing of the fundamental mode directly changed into the squeezing of the harmonic in the degenerate frequency upconversion process. All reachable conditions of uncorrelated modes for obtaining a sum squeezing in two modes and its dependence on the squeezing of individual field modes are investigated. It is found that the squeezed states are associated with large number of pump photons. It is also confirmed that the higher-order squeezing (sum squeezing) is directly associated with coupling of the field and interaction time.

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