US 12,248,865 B2
Systems and methods for modeling continuous stochastic processes with dynamic normalizing flows
Ruizhi Deng, Coquitlam (CA); Bo Chang, Toronto (CA); Marcus Anthony Brubaker, Toronto (CA); Gregory Peter Mori, Burnaby (CA); and Andreas Steffen Michael Lehrmann, Vancouver (CA)
Assigned to ROYAL BANK OF CANADA, Toronto (CA)
Filed by ROYAL BANK OF CANADA, Toronto (CA)
Filed on Feb. 8, 2021, as Appl. No. 17/170,416.
Claims priority of provisional application 62/971,143, filed on Feb. 6, 2020.
Prior Publication US 2021/0256358 A1, Aug. 19, 2021
Int. Cl. G06N 3/047 (2023.01); G06N 3/08 (2023.01)
CPC G06N 3/047 (2023.01) [G06N 3/08 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system for a machine learning architecture for time series data prediction comprising:
a processor; and
a memory coupled to the processor and storing processor-executable instructions that, when executed, configure the processor to:
obtain time series data associated with a data query;
generate a predicted value by executing a machine learning application based on a sampled realization of the time series data, the machine learning application comprising a continuous time generative model trained to define an invertible mapping to maximize a log-likelihood of a set of predicted values for a time range associated with the time series data, wherein generation of the predicted value comprises:
computing the predicted value based on a joint distribution Xτ=Fθ(Wτ;τ), ∀τ∈[0, T], where Fθ(⋅; τ):custom characterdcustom characterd is the invertible mapping parametrized by the learnable parameters θ for every τ∈[0, T], and Wτ is a d-dimensional Wiener process, such that the log-likelihood

OG Complex Work Unit Math
is maximized, where pX(x) represents a probability density function of x;
wherein the invertible mapping is based on solving an initial value problem defined by:

OG Complex Work Unit Math
where hτ(t)∈custom characterd, t∈[t0,t1], ƒθ:custom characterd×custom character×[t0,t1]→custom characterd, and gθ:custom character×[to,t1]→custom character, and the joint distribution Fθ(wτ; τ) is defined as a solution of hτ(t); and
generate a signal providing an indication of the predicted value associated with the data query for performing a downstream task.