AI Agent Rare-Event Estimation Using Importance Sampling

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Solution Overview

Problem

Traditional verification approaches for machine learning systems struggle to accurately assess the risk of rare events, particularly in complex and autonomous systems, due to computational inefficiencies and reliance on unrealistic assumptions, leading to potential safety and security vulnerabilities.

Innovation Solution

Employing statistical methods and reinforcement learning techniques to analyze historical data, modify system dynamics, and use importance sampling to estimate the probability of rare events, allowing for proactive identification and mitigation of potential failures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional verification approaches are used to assess safety of machine learning systems, then verification coverage is improved, but computational cost increases significantly

Engineering Contradiction:
Improvesafety verificationVSAvoidcomputational efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the parameter of probability estimation by using importance sampling to focus computational resources on rare failure modes rather than uniform sampling. This transforms the verification approach from exhaustive testing to targeted sampling of critical failure scenarios, improving computational efficiency while maintaining safety verification coverage

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary analysis to identify failure modes and their probabilities before conducting full verification. By pre-characterizing the failure landscape and using this information to guide subsequent verification efforts, the system avoids unnecessary computational expenditure on already-understood safe operating conditions

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If Monte Carlo simulations are used to estimate rare event probabilities, then measurement precision is improved, but loss of time increases

Engineering Contradiction:
Improverare event probability estimationVSAvoidcomputational time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent transforms the sampling distribution parameter by introducing importance sampling with carefully chosen proposal distributions that concentrate samples in regions where rare events occur. This parameter change allows achieving the same measurement precision with dramatically fewer samples, reducing computational time from potentially millions of simulations to a manageable number of targeted samples

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies partial action by focusing computational effort only on the critical regions of the state space where rare failures occur, rather than uniformly sampling the entire space. By using importance sampling to overweight samples from failure-prone regions and underweight or ignore samples from safe regions, the system achieves accurate rare event estimation with reduced overall computational time

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If traditional verification methods are applied to complex machine learning models, then reliability assessment is improved, but device complexity increases

Engineering Contradiction:
Improvesystem safety assessmentVSAvoidverification system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the verification process into distinct modules: failure mode identification, probability estimation using importance sampling, and risk assessment. This segmentation allows each component to be developed and validated independently, reducing the overall complexity of the verification system while maintaining comprehensive safety assessment capabilities for complex machine learning models

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS20250278650A1Rare events estimation
Publication Date: 2025.09.04 SRI INTERNATIONAL
  • US20250278650A1 patent drawing
  • US20250278650A1 patent drawing
  • US20250278650A1 patent drawing

AI summary

In an example, a method for estimation of the probability of rare events includes determining a control function that guides an Artificial Intelligence (AI) agent towards a rare region of state space; modifying, using the control function, dynamics of the behavior of the AI agent to generate modified dynamics; simulating behavior of the AI agent using the modified dynamics to generate one or more samples that are more likely to enter the rare region of the state space; assigning a weight to each of the one or more generated samples; and estimating probability of one or more rare events in the behavior of the AI agent by fitting a distribution describing behavior of the one or more rare events to the one or more weighted samples.