Neighbor-Aware Hyperbolic Embeddings for Hierarchical Recommendation Accuracy

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing recommendation systems struggle to effectively capture hierarchical information and distinguish between positive and negative data points, particularly in large-scale online systems with millions of users and items, leading to suboptimal prediction accuracy.

Innovation Solution

A recommendation system represents users and items in a multidimensional hyperbolic space using neighbor-aware embeddings, which are generated by converting local embeddings to tangent space for graph convolutions and then back to hyperbolic space, incorporating neighbor information through graph convolutions, and employs a margin-based training loss to enhance separation between positive and negative data points.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Euclidean space embedding is used to represent users and items, then the representation is simple and computationally efficient, but the model cannot effectively capture hierarchical information and distinguish between positive and negative data points

Engineering Contradiction:
Improveprediction accuracyVSAvoidembedding space complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transitions from Euclidean space to hyperbolic space for embedding representations. Hyperbolic space naturally captures hierarchical information through its geometric structure, allowing the model to distinguish between positive and negative data points more effectively. This dimensional change resolves the contradiction by improving prediction accuracy through hierarchical representation while maintaining computational feasibility through established hyperbolic geometry operations.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent employs curved hyperbolic geometry instead of flat Euclidean geometry. The hyperbolic space's constant negative curvature enables exponential growth of volume with radius, allowing efficient representation of hierarchical data structures. This curvature-based approach improves the model's ability to separate positive and negative samples while maintaining a manageable representation space.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Measurement precision

If neighbor-aware embedding is implemented by converting to tangent space for graph convolutions and back to hyperbolic space, then neighbor relationships and hierarchical information are captured effectively, but the computational process becomes more complex

Engineering Contradiction:
Improveprediction accuracyVSAvoidembedding generation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces tangent space as an intermediary representation between hyperbolic space and graph convolution operations. By converting hyperbolic embeddings to tangent space, performing graph convolutions, and then mapping back to hyperbolic space, the model enables neighbor-aware representations while maintaining the benefits of hyperbolic geometry. This intermediary approach resolves the contradiction by enabling complex neighbor relationships to be captured through a systematic transformation process.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The embedding generation process is segmented into distinct steps: converting hyperbolic embeddings to tangent space, performing graph convolutions to capture neighbor information, and mapping back to hyperbolic space. This segmentation allows each component to be optimized independently and facilitates the integration of multiple information sources (hierarchical structure and neighbor relationships) without overwhelming computational complexity.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If graph convolutions are applied to incorporate neighbor information, then neighbor relationships are captured effectively, but the computational cost increases

Engineering Contradiction:
Improveprediction accuracyVSAvoidcomputational cost
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

By using tangent space as an intermediary, the patent enables efficient graph convolution operations that can be performed using standard linear algebra techniques. The transformation to and from tangent space allows neighbor information to be incorporated through matrix operations rather than more expensive iterative methods, reducing computational cost while maintaining prediction accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the mathematical parameters and operations used in the embedding space. By working in tangent space during graph convolutions and then mapping to hyperbolic space, the model leverages efficient linear algebra operations to capture neighbor relationships. This parameter change enables scalable computation while maintaining the expressive power needed for accurate predictions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS20250252479A1Recommendation with neighbor-aware hyperbolic embedding
Publication Date: 2025.08.07 THE TORONTO DOMINION BANK
  • US20250252479A1 patent drawing
  • US20250252479A1 patent drawing
  • US20250252479A1 patent drawing

AI summary

A recommendation system generates recommendations for user-item pairs based on embeddings in hyperbolic space. Each user and item may be associated with a local hyperbolic embedding representing the user or item in hyperbolic space. The hyperbolic embedding may be modified by neighborhood information. Because the hyperbolic space may have no closed form for combining neighbor information, the local embedding may be converted to a tangent space for neighborhood aggregation information and converted back to hyperbolic space for a neighborhood-aware embedding to be used in the recommendation score.