2,607 research outputs found
On the control of a linear functional- differential equation with quadratic cost
Linear functional differential equations control with quadratic cos
Monolithically integrated active optical devices
Considerations relevant to the monolithic integration of optical detectors, lasers, and modulators with high speed amplifiers are discussed. Some design considerations for representative subsystems in the GaAs-AlGaAs and GaInAs-InP materials systems are described. Results of a detailed numerical design of an electro-optical birefringent filter for monolithic integration with a laser diode is described, and early experimental results on monolithic integration of broadband MESFET amplifiers with photoconductive detectors are reported
CONVERGENCE OF AMERICAN OPTION VALUES FROM DISCRETE- TO CONTINUOUS-TIME FINANCIAL MODELS 1
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75553/1/j.1467-9965.1994.tb00059.x.pd
The filtering equations revisited
The problem of nonlinear filtering has engendered a surprising number of
mathematical techniques for its treatment. A notable example is the
change-of--probability-measure method originally introduced by Kallianpur and
Striebel to derive the filtering equations and the Bayes-like formula that
bears their names. More recent work, however, has generally preferred other
methods. In this paper, we reconsider the change-of-measure approach to the
derivation of the filtering equations and show that many of the technical
conditions present in previous work can be relaxed. The filtering equations are
established for general Markov signal processes that can be described by a
martingale-problem formulation. Two specific applications are treated
Theodicy and End-of-Life Care
Acknowledgments The section on Islamic perspective is contributed by information provided by Imranali Panjwani, Tutor in Theology & Religious Studies, King's College London.Peer reviewedPublisher PD
A fully-discrete scheme for systems of nonlinear Fokker-Planck-Kolmogorov equations
We consider a system of Fokker-Planck-Kolmogorov (FPK) equations, where the
dependence of the coefficients is nonlinear and nonlocal in time with respect
to the unknowns. We extend the numerical scheme proposed and studied recently
by the authors for a single FPK equation of this type. We analyse the
convergence of the scheme and we study its applicability in two examples. The
first one concerns a population model involving two interacting species and the
second one concerns two populations Mean Field Games
Optimal waveform estimation for classical and quantum systems via time-symmetric smoothing
Classical and quantum theories of time-symmetric smoothing, which can be used
to optimally estimate waveforms in classical and quantum systems, are derived
using a discrete-time approach, and the similarities between the two theories
are emphasized. Application of the quantum theory to homodyne phase-locked loop
design for phase estimation with narrowband squeezed optical beams is studied.
The relation between the proposed theory and Aharonov et al.'s weak value
theory is also explored.Comment: 13 pages, 5 figures, v2: changed the title to a more descriptive one,
corrected a minor mistake in Sec. IV, accepted by Physical Review
Ion energy distributions in inductively coupled plasmas having a biased boundary electrode
In many plasma materials processing applications requiring energetic ion bombardment such as plasma etching, control of the time-averaged ion energy distributions (IEDs) to surfaces is becoming increasingly important to discriminate between surface processes having different threshold energies. Inductively coupled plasmas (ICPs) are attractive in this regard since the plasma potential is low and so the energy of ion fluxes can be more finely tuned with externally applied biases. In these situations, pulsed plasmas provide another level of control as the IEDs from different times during the pulse power period can be combined to create the desired time-averaged IED. A recent development in controlling of IEDs in ICPs is the use of a boundary electrode (BE) in which a continuous or pulsed dc bias is applied to shift the plasma potential and modify the IEDs to surfaces without significant changes in the bulk plasma properties. Combinations of pulsing the ICP power and the BE bias provide additional flexibility to craft IEDs. In this paper we discuss results from a computational investigation of IEDs to a grounded substrate in low-pressure (a few to 50 mTorr) ICPs sustained in argon. Results are compared with experimental measurements of plasma properties and IEDs. We demonstrate the ability to customize IEDs consisting of three energy peaks corresponding to the plasma potential during the plasma active glow, plasma afterglow and the plasma potential with the applied boundary voltage.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98615/1/0963-0252_21_6_065009.pd
Bayesian optimization for materials design
We introduce Bayesian optimization, a technique developed for optimizing
time-consuming engineering simulations and for fitting machine learning models
on large datasets. Bayesian optimization guides the choice of experiments
during materials design and discovery to find good material designs in as few
experiments as possible. We focus on the case when materials designs are
parameterized by a low-dimensional vector. Bayesian optimization is built on a
statistical technique called Gaussian process regression, which allows
predicting the performance of a new design based on previously tested designs.
After providing a detailed introduction to Gaussian process regression, we
introduce two Bayesian optimization methods: expected improvement, for design
problems with noise-free evaluations; and the knowledge-gradient method, which
generalizes expected improvement and may be used in design problems with noisy
evaluations. Both methods are derived using a value-of-information analysis,
and enjoy one-step Bayes-optimality
Climate‐related variations in mixing dynamics in an Alaskan arctic lake
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109805/1/lno2009546part22401.pd
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