In this paper, using the theory of topological degree and Liapunov functional methods, the authors study the competitive neural networks with time delays and different time scales and present some criteria of global robust stability for this neural network model. 相似文献
Using a 90mm-bore, 3.15 m long detonation tube, experimental detonation characteristics (detonability limits, detonation
velocities and peak pressures) of stoichiometric methane-oxygen-diluent mixtures at an initial pressure up to 3.5 MPa have
been experimentally investigated. A parametric study has been carried out as a function of both amount and nature of diluent,
namely carbon dioxide, nitrogen and helium. The experimental results allowed the adjustment and validation of computations
of the Chapman-Jouguet characteristics by means of a thermochemical code. These experimental data associated with validated
computations provide a valuable tool, among others, for the choice of the most appropriate mixture composition in the superdetonative
combustion mode for ram accelerator (ramac) experiments. The investigations were organized to determine the upper detonable
areas of dense ternary mixtures, and to provide detonation velocity data in order to adjust a series of intermolecular parameters
involved in the thermochemical code.
Received 8 May 1997 / Accepted 15 December 1997 相似文献
This paper deals with the class of uncertain systems with multiple time delays. The stability and stabilizability of this class of systems are considered. System robustness is also studied when the norm-bounded uncertainties are considered. LMI delay-dependent sufficient conditions for stability, stabilizability, and system robustness are established to check whether a system of this class is stable and/or stabilizable. Numerical examples are provided to show the usefulness of the proposed results. 相似文献
Two types of Equations of State (EoS), which are characterized here as “simple” and “complex” EoS, are evaluated in this study. The “simple” type involves two versions of the Peng–Robinson (PR) EoS: the traditional one that utilizes the experimental critical properties and the acentric factor and the other, referred to as PR-fitted (PR-f), where these parameters are determined by fitting pure compound vapor pressure and saturated liquid volume data. As “complex” EoS in this study are characterized the EoS derived from statistical mechanics considerations and involve the Sanchez–Lacombe (SL) EoS and two versions of the Statistical Associating Fluid Theory (SAFT) EoS, the original and the Perturbed-Chain SAFT (PC-SAFT).
The evaluation of these two types of EoS is carried out with respect to their performance in the prediction and correlation of vapor liquid equilibria in binary and multicomponent mixtures of methane or ethane with alkanes of various degree of asymmetry. It is concluded that for this kind of systems complexity offers no significant advantages over simplicity. Furthermore, the results obtained with the PR-f EoS, especially those for multicomponent systems that are encountered in practice, even with the use of zero binary interaction parameters, indicate that this EoS may become a powerful tool for reservoir fluid phase equilibria modeling. 相似文献
We study a linear discrete-time partially observed system perturbed by a white noise. The observations are transmitted to
the estimator via communication channels with irregular transmission times. Various measurement signals may incur independent
delays, arrive at the estimator out of order, and be lost or corrupted. The estimator is given a dynamic control over the
sensors by taking part in producing the signals to be sent via the channels. The minimum variance state estimate and the optimal
sensor control strategy are obtained. Ideas of model predictive control are applied to derive a nonoptimal but implementable
in real time method for sensor control
This work was supported by the Australian Research Council. 相似文献
The design of a robust mixed H2/H∞ controller for a class of uncertain neutral systems with discrete, distributed, and input time-varying delays is considered. More precisely, the proposed robust mixed H2/H∞ controller minimizes an upper bound of the H2 performance measure, while guaranteeing an H∞ norm bound constraint. Based on the Lyapunov-Krasovskii functional theory, a delay-dependent criterion is derived for the existence of a desired mixed H2/H∞ controller, which can be constructed easily via feasible linear matrix inequalities (LMIs). Furthermore, a convex optimization problem satisfying some LMI constraints is formulated to obtain a suboptimal robust mixed H2/H∞ controller achieving the minimization of an upper bound of the closed-loop H2 performance measure. Finally, a numerical example is illustrated to show the usefulness of the obtained design method.The research reported here was supported by the National Science Council of Taiwan, ROC under Grant NSC 94-2213-E-507-002. 相似文献
In this paper, the dynamics of a generalized two-neuron model with self-connections and distributed delays are investigated, together with the stability of the equilibrium. In particular, the conditions under which the Hopf bifurcation occurs at the equilibrium are obtained for the weak kernel. This means that a family of periodic solutions bifurcates from the equilibrium when the bifurcation parameter exceeds a critical value. Explicit algorithms for determining the stability of the bifurcating periodic solutions and the direction of the Hopf bifurcation are derived by using the theory of normal form and center manifold [20]. Some numerical simulations are given to illustrate the effectiveness of the results found. The obtained results are new and they complement previously known results.This work was supported by the National Natural Science Foundation of China under Grants 60574043 and 60373067, the Natural Science Foundation of Jiangsu Province, China under Grants BK2003053. 相似文献