7,423 research outputs found
Multivariable predictive PID control for quadruple tank
In this paper multivariable predictive PID controller has been implemented on a multi-inputs multi-outputs control problem i.e., quadruple tank system, in comparison with a simple multiloop PI controller. One of the salient feature of this system is an adjustable transmission zero which can be adjust to operate in both minimum and non-minimum phase configuration, through the flow distribution to upper and lower tanks in quadruple tank system. Stability and performance analysis has also been carried out for this highly interactive two input two output system, both in minimum and non-minimum phases. Simulations of control system revealed that better performance are obtained in predictive PID design
Population balances in case of crossing characteristic curves: Application to T-cells immune response
The progression of a cell population where each individual is characterized
by the value of an internal variable varying with time (e.g. size, weight, and
protein concentration) is typically modeled by a Population Balance Equation, a
first order linear hyperbolic partial differential equation. The
characteristics described by internal variables usually vary monotonically with
the passage of time. A particular difficulty appears when the characteristic
curves exhibit different slopes from each other and therefore cross each other
at certain times. In particular such crossing phenomenon occurs during T-cells
immune response when the concentrations of protein expressions depend upon each
other and also when some global protein (e.g. Interleukin signals) is also
involved which is shared by all T-cells. At these crossing points, the linear
advection equation is not possible by using the classical way of hyperbolic
conservation laws. Therefore, a new Transport Method is introduced in this
article which allowed us to find the population density function for such
processes. The newly developed Transport method (TM) is shown to work in the
case of crossing and to provide a smooth solution at the crossing points in
contrast to the classical PDF techniques.Comment: 18 pages, 10 figure
Bayesian Conditional Density Filtering
We propose a Conditional Density Filtering (C-DF) algorithm for efficient
online Bayesian inference. C-DF adapts MCMC sampling to the online setting,
sampling from approximations to conditional posterior distributions obtained by
propagating surrogate conditional sufficient statistics (a function of data and
parameter estimates) as new data arrive. These quantities eliminate the need to
store or process the entire dataset simultaneously and offer a number of
desirable features. Often, these include a reduction in memory requirements and
runtime and improved mixing, along with state-of-the-art parameter inference
and prediction. These improvements are demonstrated through several
illustrative examples including an application to high dimensional compressed
regression. Finally, we show that C-DF samples converge to the target posterior
distribution asymptotically as sampling proceeds and more data arrives.Comment: 41 pages, 7 figures, 12 table
Effect of phase fluctuation and dephasing on the dynamics of entanglement generation in a correlated emission laser
A detailed study of the effects of phase fluctuation and dephasing on the
dynamics of the entanglement generated from a coherently pumped correlated
emission laser is presented. It is found that the time evolution of the
entanglement is significantly reliant on the phase fluctuation and dephasing,
particularly, at early stages of the lasing process. In the absence of external
driving radiation, the degree of entanglement and intensity turns out to attain
a maximum value just before starting to exhibit oscillation which dies at
longer time scale. However, in case the driving mechanism is on, the
oscillatory nature disappears due to the additional induced coherent
superposition and the degree of entanglement would be larger at steady state.
Moreover, the degree of entanglement as predicted by the logarithmic negativity
and the Duan-Giedke-Cirac-Zoller criteria exhibits a similar nature when there
is no driving radiation, although such a trend is eroded with increasing
strength of the pumping radiation at longer time scale. The other important
aspect of the phase fluctuation and dephasing is the possibility of relaxing
the time at which the maximum entanglement is detected.Comment: 10 pages, 10 figure
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