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Escape Time (escape + time)

Distribution by Scientific Domains

Engineering	50%

Selected Abstracts

Stabilization of complex cascade systems using boundedness information in finite time

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 10 2009
Huawen Ye
Abstract In this paper, the stabilization problem of several classes of complex cascade systems is investigated from a new point of view. If the closed-loop system is proven to have no finite escape time, the boundedness information in finite time, which is obtained from robust stable subsystems or recursive analysis procedures, is then sufficiently employed to deal with crucial nonlinear terms. The proposed method does not rely on complicated Lyapunov functions, and in some cases it can avoid strong growth conditions and complicated small gain analysis. In addition, simple saturated control laws are explicitly constructed in an almost unified way. Copyright © 2008 John Wiley & Sons, Ltd. [source]

The role of phonons in establishing a non-equilibrium quasiparticle state in small gap multiple tunnelling superconducting tunnel junctions

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 11 2004
A. G. Kozorezov
Abstract We derive expressions for phonon escape times from a thin superconducting film. The escape time is determined by the rate of scattering conversion for phonons propagating beyond the critical cone for total internal reflection. The conversion is due to different scattering processes for the groups of Cooper pair breaking and sub-gap phonons. For pair breaking phonons the most efficient conversion mechanism is through the interaction with the condensate. For sub-gap phonons the conversion rate is much slower and for plane parallel films is due to elastic scattering at surface or interface roughness resulting in significantly slower escape times. We discuss implications of slow escape time for sub-gap phonons for the properties of the recently observed new non-equilibrium state in small gap multiple tunnelling superconducting tunnel junctions. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Stabilization for a class of complex interlaced systems using asymptotical gain,

ASIAN JOURNAL OF CONTROL, Issue 2 2010
Huawen Ye
Abstract This paper addresses the stabilization problem of a class of interlaced systems that are not in a strict-feedforward form and contain some severe nonlinear terms. Bounded control laws in a fractional form are explicitly constructed. The feature of stability analysis allows the closed-loop system, when it is proven to have no finite escape time, to employ the asymptotical gain, which is obtained from an input-to-state stable (ISS) subsystem, to calculate the severe nonlinear terms, and the related estimate in turn guides the assignment of small controls. Together with the use of the passivity theory and the ISS-based stability criterion, the proposed method requires no small gain analysis although the asymptotical gain is used, and differs from the state-dependent saturation scheme since the controls do not include saturation functions. As an application, a new stabilizing control law is presented for the well-known friction ball-and-beam system. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source]