293,179 research outputs found
Frequency domain criteria for lp-robust stability of systems with fuzzy parameters
The paper deals with the problem of determining stability margin of linear continuous-time system with fuzzy parametric uncertainty. Non-symmetric multivariate membership functions with lp -constraints describing the uncertainty of characteristic polynomial parameters are considered. An elegant solution, graphical in nature, based on generation of Tsypkin-Polyak plot is presented
Evolutionary optimization of a fed-batch penicillin fermentation process
This paper presents a genetic algorithms
approach for the optimization of a fed-batch penicillin
fermentation process. A customized float-encoding
genetic algorithm is developed and implemented to a
benchmark fed-batch penicillin fermentation process.
Off-line optimization of the initial conditions and set
points are carried out in two stages for a single variable
and multiple variables. Further investigations with online
optimization have been carried out to demonstrate
that the yield can be significantly improved with an
optimal feed rate profile. The results have shown that the
proposed approaches can be successfully applied to
optimization problems of fed-batch fermentation to
improve the operation of such processes
Shaping of molecular weight distribution using b-spline based predictive probability density function control
Issues of modelling and control of molecular weight distributions (MWDs) of polymerization products have been studied under the recently developed framework of stochastic distribution control, where the purpose is to design the required control inputs that can effectively shape the output probability density functions (PDFs) of the dynamic stochastic systems. The B-spline Neural Network has been implemented to approximate the function of MWDs provided by the mechanism model, based on which a new predictive PDF control strategy has been developed. A simulation study of MWD control of a pilot-plant styrene polymerization process has been given to demonstrate the effectiveness of the algorithms
A Primary Study of Heavy Baryons Lambda_Q, Xi_Q, Sigma_Q and Omega_Q
We perform a preliminary study of the 1/2+ and 3/2+ ground-state baryons
containing a heavy quark in the framework of the chiral SU(3) quark model. By
using the calculus of variations, masses of Lambda_Q, Sigma_Q, Xi_Q, Omega_Q,
Sigma_Q^*, Xi_Q^* and Omega_Q^*, where Q means c or b quark, are calculated.
With taking reasonable model parameters, the numerical results of established
heavy baryons are generally in agreement with the available experimental data,
except that those of Xi_Q are somewhat heavier. For Omega_b with undetermined
experimental mass and nobserved Xi_b^*, Omega_b^*, reasonable theoretical
predictions are obtained. Interactions inside baryons are also discussed.Comment: 5 page
- …