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Showing 1 to 12 of 12 for “"Imaginary axis"”.
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H[infinity] static feedback control with and without imaginary axis zeros for missle autopilot design
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1992.
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Solution of Nonsymmetric Systems of Equations on a Multiprocessor
… whose eigenvalues lie on both sides of the imaginary axis, or whose symmetric part is not positive definite. This system of equations is solved using the projection methods with conjugate gradient acceleration. The algorithm has been designed with special emphasis on its suitability for …
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Nonlinear, conditionally stable, singularly perturbed boundary-relation problems
… is bounded away and to the left of the imaginary axis and the spectrum of A$\sb2$(t,x) is bounded away and to the right of the imaginary axis. Suppose also that p$\sb0$(t) is a solution of the reduced differential equation p$\sb0\sp\prime$(t) = f(t,p$\sb0$(t),$\phi$(t,p$\sb0$(t)),0) and …
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Hamiltonian bifurcations in Schrodinger trimers
… Hopf bifurcation occurs when eigenvalues on the imaginary axis collide and split and has two types: elliptic and hyperbolic. These two types arise in the DNLS problem, and the families of periodic orbits are discussed as a conserved quantity N is changed. The stability of each standing wave …
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Investigations of Black-Hole Spectra: Purely-Imaginary Modes and Kerr Ringdown Radiation
… the real part represents oscillation and the imaginary part represents damping. We have developed a new code for calculating QNM with high precision and accuracy, which we applied to the Schwarzschild and Kerr geometries. The high accuracy of our calculations was a significant improvement over …
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Stability of planar fronts for a class of reaction diffusion systems
… in the direction of the front touches the imaginary axis. This setting is a generalization of the relevant multidimensional stability results known in the literature. Passing to the exponential weights, we obtain appropriate estimates for the nonlinear terms of the equation govering the …
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New Results on Time-Delay Systems Towards Model-Based Design
… in a complex plane. If the roots cross the imaginary axis of the system, it is said to be Delay-Dependent Stable System (DDSS). A controller design procedure for Commensurate Multiple Time-Delay Systems (CMTDSs) is developed, able to transform the system into a Delay Independent Stable …
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A Spatial Dynamic Approach to Three-Dimensional Gravity-Capillary Water Waves
… algebraic multiplicity and the number of purely imaginary eigenvalues are finite. The distribution of eigenvalues is described by b and λ. Assume that C₁ is the curve in (b,λ)-plane on which the first two eigenvalues for three-dimensional waves collide at the imaginary axis, and that the …
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A study of stochastic processes in Banach spaces
… the resolvent of Λ is uniformly bounded on the imaginary axis. Both Zt and Bt are stochastic integrals with respect to a spectral Q-Wiener process. The convolution of two arcsine probability densities is shown to be an elliptic integral. Ensembles (Xn)n≥1 of random Hermitian matrices are …
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Effective development of cylindrical finite-difference time-domain for electromagnetics applications
… of the PML is low especially near to the z-axis and for low frequency applications. Complex frequency shifted convolutional PML (CFS-PML) is a technique that is capable (when fully implemented) of absorbing evanescent waves by shifting the frequency poles in the imaginary axis. Such …
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Random perturbations of delay differential equations at the verge of instability and periodically driven nonlinear oscillators
… equation (critical eigenvalues) lie on the imaginary axis of the complex plane, and all other roots have negative real parts (stable eigenvalues). The effect of deterministic perturbations on such DDE is analytically well-studied in the literature. For noise perturbations with noise as a …