%0 Journal Article
%T Introducing the n<sup>th</sup>-Order Features Adjoint Sensitivity Analysis Methodology for Nonlinear Systems (n<sup>th</sup>-FASAM-N): I. Mathematical Framework
%A Dan Gabriel Cacuci
%J American Journal of Computational Mathematics
%P 11-42
%@ 2161-1211
%D 2024
%I Scientific Research Publishing
%R 10.4236/ajcm.2024.141002
%X This work presents the ¡°nth-Order Feature
Adjoint Sensitivity Analysis Methodology for Nonlinear Systems¡± (abbreviated as
¡°nth-FASAM-N¡±), which will be shown to be the most efficient
methodology for computing exact expressions of sensitivities, of any order, of
model responses with respect to features of model parameters and, subsequently,
with respect to the model¡¯s uncertain parameters, boundaries, and internal
interfaces. The unparalleled efficiency and accuracy of the nth-FASAM-N
methodology stems from the maximal reduction of the number of adjoint
computations (which are considered to be ¡°large-scale¡± computations) for
computing high-order sensitivities. When applying the nth-FASAM-N
methodology to
compute the second- and higher-order sensitivities, the number of large-scale
computations is proportional to the number of ¡°model features¡± as opposed to
being proportional to the number of model parameters (which are considerably
more than the number of features).When a model has no ¡°feature¡± functions of
parameters, but only comprises primary parameters, the nth-FASAM-N
methodology becomes identical to the extant nth CASAM-N (¡°nth-Order
Comprehensive Adjoint Sensitivity Analysis Methodology for Nonlinear Systems¡±)
methodology. Both the nth-FASAM-N and the nth-CASAM-N
methodologies are formulated in linearly increasing higher-dimensional Hilbert
spaces as opposed to exponentially increasing parameter-dimensional spaces thus
overcoming the curse of dimensionality in
%K Computation of High-Order Sensitivities
%K Sensitivities to Features of Model Parameters
%K Sensitivities to Domain Boundaries
%K Adjoint Sensitivity Systems
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=132058