Logical Neural Network Guided Reinforcement Learning for Polymer Discovery

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Solution Overview

Problem

Current polymer discovery processes are inefficient due to sample inefficiency in reinforcement learning (RL) environments, lack of reasoning capabilities, and limited access to conceptual scientific knowledge, leading to numerous useless decisions and exceeding time and budget constraints.

Innovation Solution

Integration of a logical optimal action (LOA) framework within an RL environment using a logical neural network (LNN) that develops policy rules based on a large polymer training dataset constrained by subject matter expert (SME) rules, ensuring the RL agent makes decisions that advance polymer discovery goals and eliminates useless decisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If reinforcement learning is applied to polymer discovery without constraints, then the RL agent can explore a wide range of decisions, but it generates numerous useless decisions that waste time and resources

Engineering Contradiction:
Improvedecision exploration capabilityVSAvoidtraining time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The LNN is trained beforehand on polymer domain knowledge and constraints to generate policy rules that guide the RL agent. This preliminary preparation of decision-making guidelines prevents the RL agent from exploring useless decision spaces during training, thereby reducing training time while maintaining adaptability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The LNN acts as an intermediary between domain knowledge and the RL agent. It translates polymer discovery constraints and expertise into policy rules that the RL agent can follow, filtering out useless decisions before they are executed, thus reducing wasted training time.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Extent of automation

If standard reinforcement learning approaches are used, then the system can learn through rewards, but it lacks reasoning capability to distinguish useful from useless decisions

Engineering Contradiction:
Improveautonomous learning capabilityVSAvoidreasoning capability
Core Design Contradiction:
Extent of automationVSLoss of information

Solution Approach 1:

The system merges the autonomous learning capability of RL with the reasoning capability of LNN. The LNN provides logical reasoning and domain knowledge guidance, while the RL agent performs autonomous reward-based learning. Together, they enable the system to both learn autonomously and reason about decision quality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The decision-making system is composed of two complementary components: the LNN that provides reasoning-based policy rules and the RL agent that provides reward-based learning. This composite approach combines the strengths of both methods to achieve both reasoning capability and autonomous learning.

Inventive Principle:
Principle #40Composite materials

3Reliability

If enormous training data is used to overcome sample inefficiency, then the RL agent can learn better policies, but it exceeds realistic time and budget constraints

Engineering Contradiction:
Improvepolicy qualityVSAvoiddiscovery rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The LNN extracts essential polymer domain knowledge and constraints from existing data and expertise, forming policy rules that guide the RL agent. This extraction process concentrates the most important information into compact rules, reducing the need for enormous training datasets while maintaining policy quality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system changes the parameter of data efficiency by introducing LNN-generated policy rules as additional guidance signals. This allows the RL agent to learn effective policies with fewer training samples, improving productivity without sacrificing policy reliability.

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If the RL agent makes unrestricted decisions, then it can potentially discover novel polymers, but it makes decisions that do not advance the discovery goal

Engineering Contradiction:
Improvediscovery potentialVSAvoiddecision quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The LNN policy rules serve multiple functions: they constrain the RL agent's decision space to meaningful options, provide domain knowledge guidance, and maintain discovery potential. This multi-functional approach ensures decisions are both novel and scientifically sound.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system dynamically balances exploration and exploitation by allowing the RL agent to make novel decisions within the bounds of LNN policy rules. The policy rules adapt to guide the agent toward promising regions of the decision space while preserving the ability to discover new polymers.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS20240330694A1Polymer discovery via reinforcement learning with expert-defined logical actions
Publication Date: 2024.10.03 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US20240330694A1 patent drawing
  • US20240330694A1 patent drawing
  • US20240330694A1 patent drawing

AI summary

A reward-based reinforcement learning (RL) computing environment with an RL agent has a goal to discovery new polymers. The RL environment is integrated with a logical optimal action (LOA) framework that includes a logical neural network (LNN). The RL environment and the LOA framework share a user interface that switches between the LOA framework and the RL environment. At the LOA interface, polymer datasets are entered into the LOA framework along with subject matter expert (SME)-defined rules that limit the scope of the information in the datasets. The datasets and the SME-defined rules train the LNN to develop policy rules. Upon training completion, the datasets and the LNN policy rules are input into the RL environment where the RL agent makes reward-based decisions on the information in the datasets that advance the goal. At the RL interface, the SME reviews the RL agent's decisions to eliminate decisions that do not advance the goal.