Finite amplitude envelope solitons

1977 ◽  
Vol 20 (8) ◽  
pp. 1286 ◽  
Author(s):  
H. Schamel ◽  
M. Y. Yu ◽  
P. K. Shukla
Keyword(s):  
Finite Amplitude ◽  
Amplitude Envelope ◽  
Envelope Solitons

Stability of two-dimensional finite-amplitude envelope solitons

1987 ◽  
Vol 35 (10) ◽  
pp. 4273-4279 ◽  
Author(s):  
R. Blaha ◽  
E. W. Laedke ◽  
K. H. Spatschek
Keyword(s):  
Finite Amplitude ◽  
Two Dimensional ◽  
Amplitude Envelope ◽  
Envelope Solitons

Finite amplitude envelope solitons in a pair-ion plasma

2007 ◽  
Vol 14 (3) ◽  
pp. 032107 ◽  
Author(s):  
W. M. Moslem ◽  
I. Kourakis ◽  
P. K. Shukla
Keyword(s):  
Finite Amplitude ◽  
Amplitude Envelope ◽  
Envelope Solitons ◽  
Ion Plasma

Capillary–gravity waves of solitary type and envelope solitons on deep water

1993 ◽  
Vol 252 ◽  
pp. 703-711 ◽  
Author(s):  
Michael S. Longuet-Higgins
Keyword(s):  
Surface Tension ◽  
Dispersion Relation ◽  
Gravity Waves ◽  
Deep Water ◽  
Small Amplitude ◽  
Finite Amplitude ◽  
Surface Slope ◽  
Carrier Wave ◽  
Envelope Solitons ◽  
Special Case

The existence of steady solitary waves on deep water was suggested on physical grounds by Longuet-Higgins (1988) and later confirmed by numerical computation (Longuet-Higgins 1989; Vanden-Broeck & Dias 1992). Their numerical methods are accurate only for waves of finite amplitude. In this paper we show that solitary capillary-gravity waves of small amplitude are in fact a special case of envelope solitons, namely those having a carrier wave of length 2π(T/ρg)1½2 (g = gravity, T = surface tension, ρ = density). The dispersion relation $c^2 = 2(1-\frac{11}{32}\alpha^2_{\max)$ between the speed c and the maximum surface slope αmax is derived from the nonlinear Schrödinger equation for deep-water solitons (Djordjevik & Redekopp 1977) and is found to provide a good asymptote for the numerical calculations.

scholarly journals Evolution of nonlinearly coupled drift wave-zonal flow system in a nonuniform magnetoplasma

2010 ◽  
Vol 76 (5) ◽  
pp. 665-671 ◽  
Author(s):  
D. JOVANOVIC ◽  
P. K. SHUKLA ◽  
B. ELIASSON
Keyword(s):  
Numerical Solutions ◽  
Modulational Instability ◽  
Zonal Flow ◽  
Finite Amplitude ◽  
Zonal Flows ◽  
Localized Solutions ◽  
Drift Wave ◽  
Envelope Solitons ◽  
Cubic Nonlinear Schrödinger Equation ◽  
Special Case

AbstractThe amplitude modulation of a finite amplitude drift wave by zonal flows in a non-uniform magnetoplasma is considered. The evolution of a nonlinearly coupled drift wave-zonal flow (DW-ZF) system is governed by a nonlinear equation for the slowly varying envelope of the drift waves, which drives (via the Reynolds stress of the drift wave envelope) the second equation for zonal flows. The nonlinear dispersion relation for the modulational instability of a drift wave pump is derived and analyzed. In a special case, the DW-ZF system of equations reduces to the cubic nonlinear Schrödinger equation, which admits localized solutions in the form of DW envelope solitons, accompanied by a shock-like ZF structure. Numerical solutions of the nonlinearly coupled DW-ZF systems reveal that an arbitrary spatial distribution of the DW rapidly decays into an array of localized drift wave structures, propagating with different speeds, that are robust and, in many respect, behave as solitons. The corresponding ZF evolves into the sequence of shocks that produces a strong shearing, i.e. multiple plasma flows in alternating directions.

Finite amplitude envelope surface solitons

2008 ◽  
Vol 15 (4) ◽  
pp. 042301 ◽  
Author(s):  
W. M. Moslem ◽  
M. Lazar ◽  
P. K. Shukla
Keyword(s):  
Finite Amplitude ◽  
Amplitude Envelope ◽  
Envelope Surface

Effect of Consonant-Vowel Ratio Modification on Amplitude Envelope Cues for Consonant Recognition

1991 ◽  
Vol 34 (2) ◽  
pp. 415-426 ◽  
Author(s):  
Richard L. Freyman ◽  
G. Patrick Nerbonne ◽  
Heather A. Cote
Keyword(s):  
White Noise ◽  
Intensity Ratio ◽  
Recognition Performance ◽  
Amplitude Envelope ◽  
Signal To Noise ◽  
Noise Masking ◽  
Spectral Cues ◽  
Consonant Recognition ◽  
Nonlinear Amplification ◽  
Speech Envelope

This investigation examined the degree to which modification of the consonant-vowel (C-V) intensity ratio affected consonant recognition under conditions in which listeners were forced to rely more heavily on waveform envelope cues than on spectral cues. The stimuli were 22 vowel-consonant-vowel utterances, which had been mixed at six different signal-to-noise ratios with white noise that had been modulated by the speech waveform envelope. The resulting waveforms preserved the gross speech envelope shape, but spectral cues were limited by the white-noise masking. In a second stimulus set, the consonant portion of each utterance was amplified by 10 dB. Sixteen subjects with normal hearing listened to the unmodified stimuli, and 16 listened to the amplified-consonant stimuli. Recognition performance was reduced in the amplified-consonant condition for some consonants, presumably because waveform envelope cues had been distorted. However, for other consonants, especially the voiced stops, consonant amplification improved recognition. Patterns of errors were altered for several consonant groups, including some that showed only small changes in recognition scores. The results indicate that when spectral cues are compromised, nonlinear amplification can alter waveform envelope cues for consonant recognition.

Sign in / Sign up

Export Citation Format

Share Document