Graphical Stability Criteria for Large-Scale Nonlinear Multiloop Systems

1975 ◽  
Vol 8 (1) ◽  
pp. 600-605 ◽  
Author(s):  
J.D. Blight ◽  
N.H. McClamroch
Keyword(s):  
Large Scale ◽  
Stability Criteria

Survival Criteria for Passenger Roll-On/Roll-Off Vessels and Survival Time

2007 ◽  
Vol 44 (01) ◽  
pp. 27-34
Author(s):  
Maciej Pawtowski
Keyword(s):  
Survival Time ◽  
No Value ◽  
Large Scale ◽  
Direct Link ◽  
Stability Criteria ◽  
Damage Stability ◽  
Passenger Ships ◽  
S Factor ◽  
Control Decision ◽  
Time To Capsize

The paper addresses the problem of damage stability criteria with reference to survival time, that is, the time available for evacuation of passengers on a damaged passenger roll-on/roll-off (RO/RO) vessel undergoing large-scale flooding on the car deck. The current various proposals at the International Maritime Organization (IMO) for the s factor (probability of surviving a given flooding) make no reference to survival time. The paper shows a direct link of the "prime" s factor with the time to capsize. This link has unprecedented value for a flooding control decision support system used during a crisis on board passenger ships but is of no value for the designer for whom the s factor means simply probability of surviving with adequate survival time. The paper shows how to utilize experimental data from 30-minute test runs for survival criteria based on longer duration of tests.

scholarly journals Absolute Stability Criteria for Large-Scale Lurie Direct Control Systems with Time-Varying Coefficients

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Fucheng Liao ◽  
Di Wang
Keyword(s):  
Control Systems ◽  
Absolute Stability ◽  
Large Scale ◽  
Time Derivative ◽  
Time Varying ◽  
Stability Criteria ◽  
Direct Control ◽  
Constant Matrix ◽  
Varying Coefficients ◽  
Time Varying Coefficients

The absolute stability of large-scale Lurie direct control systems with time-varying coefficients is investigated. Based on the decomposition method for large-scale systems and technique of the nonsingularM-matrix, a suitable scalar Lyapunov function as a weighted sum is constructed. By estimating its total time derivative, some absolute stability criteria and practical corollaries are derived. Furthermore, the results are extended to multiple nonlinearities. The salient feature of this paper is that the criteria which we propose allow for the situation that the norms of time-varying coefficients are unbounded. The main idea of the methodology is that even if the coefficients are norm-unbounded, by restricting their relative magnitude, the problem of negative definiteness for the derivative can also be changed into the problem of stability for a constant matrix. Finally, some numerical examples are included to illustrate the effectiveness of the proposed criteria.

Stability of stationary barotropic modons by Lyapunov's direct method

1990 ◽  
Vol 211 ◽  
pp. 393-416 ◽  
Author(s):  
H. Sakuma ◽  
M. Ghil
Keyword(s):  
Coherent Structures ◽  
Shallow Water Equations ◽  
Arbitrary Shape ◽  
Total Mass ◽  
Large Scale ◽  
Direct Method ◽  
Sufficient Condition ◽  
Stability Criteria ◽  
Small Perturbations ◽  
Formal Stability

A new Lyapunov stability condition is formulated for the shallow-water equations, using a gauge-variable formalism. This sufficient condition is derived for the class of perturbations that conserve the total mass. It is weaker than existing stability criteria, i.e. it applies to a wider class of flows. Formal stability to infinitesimally small perturbations of arbitrary shape is obtained for two classes of large-scale geophysical flows: pseudo-eastward flow with constant shear, and localized coherent structures of modon type.

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

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