Title Information
Title
Moderate Deviations and Subsolution-Based Importance Sampling for Recursive Stochastic Algorithms
Name: Personal
Name Part
Johnson, Dane Michael
Role
Role Term: Text
creator
Origin Information
Copyright Date
2015
Physical Description
Extent
8, 100 p.
digitalOrigin
born digital
Note
Thesis (Ph.D. -- Brown University (2015)
Name: Personal
Name Part
Dupuis, Paul
Role
Role Term: Text
Director
Name: Personal
Name Part
Ramanan, Kavita
Role
Role Term: Text
Reader
Name: Personal
Name Part
Budhiraja, Amarjit
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. Applied Mathematics
Role
Role Term: Text
sponsor
Genre (aat)
theses
Abstract
We prove a moderate deviations principle for the continuous time linear interpolation of discrete time recursive stochastic processes, and then investigate importance sampling schemes based on subsolutions to the Hamilton-Jacobi-Bellman equation associated with the moderate deviations structure. Both the proof of the moderate deviations principle itself as well as the proof of the asymptotic performance of importance sampling schemes based on moderate deviations rely on proving tightness of the empirical measures of the conditional means of the controlled noises as well as the controlled processes themselves. This is more complex than what is needed in the large deviation setting primarily because of the moderate deviations scaling which amplifies the noise and the weaker assumptions imposed on the moment generating function. The main tools used are the relative entropy representation of exponential integrals and the weak convergence of probability measures. The resulting moderate deviations structure is essentially a linear approximation of the large deviations dynamics and a quadratic approximation of the large deviations costs, both centered around the law of large numbers limit. Consequently importance sampling schemes based on moderate deviations subsolutions generally don't perform as well as their large deviations counterparts, but the subsolutions themselves are typically easier to find. For this reason we recommend using importance sampling based on moderate deviations when finding large deviation subsolutions is prohibitively difficult, which can occur even in simple situations, or when considering events that are “rare but not too rare” so that the moderate deviation approximation centered around the law of large numbers limit captures the distributional properties which are important for determining the probability.
Subject
Topic
Weak Convergence
Subject
Topic
Importance Sampling
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/992659")
Topic
Large deviations
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20150601
Language
Language Term: Code (ISO639-2B)
eng
Language Term: Text
English
Identifier: DOI
10.7301/Z0M32T5M
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In Copyright
Access Condition: restriction on access
Collection is open for research.
Type of Resource (primo)
dissertations