We investigate reduced-space Newton-Krylov (NK) algorithms for engineering parameter optimization problems constrained by partial-differential equations. We review reduced-space and full-space optimization algorithms, and we show that the efficiency of the reduced-space strategy can be improved significantly with inexact-Hessianvector products computed using approximate second-order adjoints. R...

In this paper we propose an adaptively extrapolated proximal gradient method, which is based on the accelerated proximal gradient method (also known as FISTA), however we locally optimize the extrapolation parameter by carrying out an exact (or inexact) line search. It turns out that in some situations, the proposed algorithm is equivalent to a class of SR1 (identity minus rank 1) proximal quas...

For a one-parameter deformation of an analytic complex function germ of several variables, there is defined its monodromy zeta-function. We give a Varchenko type formula for this zeta-function if the deformation is non-degenerate with respect to its Newton diagram.

Current numerical conformal bootstrap techniques carve out islands in theory space by repeatedly checking whether points are allowed or excluded. We propose a new method for searching that replaces the binary information "allowed"/"excluded" with continuous "navigator" function is negative region and positive excluded region. Such navigator allows one to efficiently explore high-dimensional par...

A physics-based multi-cell electro-thermal equivalent circuit model is described which is applied to the large-signal microwave characterization of AlGaAs/GaAs HBTs. This highly efficient model, which incorporates a new multi-finger electro-thermal model, has been used to perform DC, small-signal and load-pull characterization and investigate parameter-spreads due to fabrication process variati...

We study statistical estimators computed using iterative optimization methods that are not run until completion. Classical results on maximum likelihood (MLEs) assert a one-step estimator (OSE), in which single Newton-Raphson iteration is performed from starting point with certain properties, asymptotically equivalent to the MLE. further develop these early-stopping by deriving properties of de...

The delta function gauge of the electromagnetic potential allows semiclassical formulas to be obtained for the probability of exciting a single electron out of the ground state in an ultrarelativistic heavy ion reaction. Exact formulas have been obtained in the limits of zero impact parameter and large, perturbative, impact parameter. The perturbative impact parameter result can be exploited to...

The multi-parameter full waveform inversion (FWI) that integrates velocity and density can make use of the kinematic dynamic information measured data to reconstruct underground model. However, it faces problems crosstalk between multiple parameters strong nonlinearity. This research proposes a multi-constrained, FWI framework based on projected quasi-Newton algorithm. introduce types prior geo...