Results 171 to 180 of about 649 (213)

Modulational instabilities in discrete lattices

Physical Review A, 1992
We study analytically and numerically modulational instabilities in discrete nonlinear chains, taking the discrete Klein-Gordon model as an example. We show that discreteness can drastically change the conditions for modulational instability; e.g., at small wave numbers a nonlinear carrier wave is unstable to all possible modulations of its amplitude ...
, Kivshar, , Peyrard
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ON THE RELATIVE (QUASI-)DISCRETENESS OF MODULES

Ring Theory 2007, 2008
In this paper we investigate the relative (quasi-) discreteness of any module M with respect to any module N. Let 0 -> N' -> N -> N '' -> 0 be an exact sequence and let M be an N-amply supplemented module. Assume that B(M/T, N) is closed under supplement submodules for every factor module M/T of M.
KESKİN TÜTÜNCÜ, DERYA, ORHAN ERTAS, NIL   +1 more
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Discrete and Profinite Modules

2000
A profinite ringΛ is an inverse limit of an inverse system {Λ i ,φ ij } of finite rings. We always assume that rings have an identity element, denoted usually by 1, and that homomorphisms of rings send identity elements to identity elements. A profinite ring Λ is plainly a compact, Hausdorff and totally disconnected topological ring; the converse is ...
Luis Ribes, Pavel Zalesskii
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Experimental Observation of Discrete Modulational Instability

Physical Review Letters, 2004
We report the first experimental observation of modulation instability in a discrete optical nonlinear array.
J, Meier, G I, Stegeman, D N, Christodoulides, Y, Silberberg, R, Morandotti, H, Yang, G, Salamo, M, Sorel, J S, Aitchison   +8 more
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Performance of Discretization Modules

1985
The goal of the performance evaluations in this chapter is to show how the discretization error decreases as the grid is refined and more computer time is used. Standard error analyses estimate the discretization error as a function of the grid sizeN (i.e., for anN byN grid), or, respectively, the grid steph = 1 /N.
John R. Rice, Ronald F. Boisvert
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A Discretely Adaptive Delta Modulation Codec

IEEE Transactions on Communications, 1981
A discretely variable slope delta modulation (DVSD) codec is described, which is suitable for integrated circuit realization. The step size is varied by a pulse number modulation method that does not require a precision digital-to-analog conversion circuit.
Kunihiko Niwa, Akira Yukawa, Atsushi Tomozawa   +2 more
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A novel translation and modulation invariant discrete-discrete uncertainty measure

IEEE International Conference on Acoustics Speech and Signal Processing, 2002
The quantification of signal localization simultaneously in time and in frequency is fundamental to a variety of signal processing applications where time-frequency analysis is to be performed on nonstationary signals. In this paper, we develop novel joint localization measures defined on equivalence classes of finitely supported discrete-time signals.
Peter C. Tay, Joseph P. Havlicek, Victor E. DeBrunner   +2 more
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Continuous and Discrete Modules

1990
Continuous and discrete modules are, essentially, generalizations of infective and projective modules respectively. Continuous modules provide an appropriate setting for decomposition theory of von Neumann algebras and have important applications to C*-algebras.
Saad H. Mohamed, Bruno J. Müller
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Discrete electroabsorption modulators with enhanced modulation depth

Journal of Lightwave Technology, 1996
In this paper, we present an investigation into factors that limited the median modulation depth of a batch of packaged discrete waveguide EA modulators to 23 dB at a wavelength of 1.55 /spl mu/m. Results from detailed measurements of the DC absorption and photocurrent spectra are used to show how stray parasitic light can perturb the absorption ...
D.G. Moodie, M.J. Harlow, M.J. Guy, S.D. Perrin, C.W. Ford, M.J. Robertson   +5 more
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On tau-discrete modules

Erzincan Üniversitesi Fen Bilimleri Enstitüsü Dergisi
An R-module M is said to be (quasi) τ-discrete if M is τ-lifting and has the property (D_2) (respectively, has the property (D_3)), where τ is a preradical in R-mod. It is shown that: (1) direct summands of a (quasi) τ-discrete module are (quasi) τ-discrete; (2) a projective module M is τ-discrete iff M/(τ(M)) is semisimple and τ(M) is QSL; (3) if a ...
Burcu Nişancı Türkmen, Ergül Türkmen   +1 more
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