Prerequisite Relationship Extraction Using Surprise and Causality

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Solution Overview

Problem

Existing methods struggle to extract unexpected preceding relationships between time-series variables that are difficult to conceive by human sense and are not useful for future prediction.

Innovation Solution

A preceding relationship extraction device and method that calculates a degree of preceding, semantic similarity, and surprise degree, and performs causality testing to identify and present significant relationships between time-series data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional methods (CCF or VAR) are used to extract preceding relationships, then the extraction process is simple, but only easily conceivable relationships are extracted and unexpected relationships are missed

Engineering Contradiction:
Improveprecision of extracting unexpected preceding relationshipsVSAvoidcomplexity of extraction system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The extraction process is divided into distinct functional modules: a preceding degree calculation unit that quantifies temporal precedence, a similarity calculation unit that measures semantic relatedness, and a surprise degree calculation unit that identifies unexpected relationships. This segmentation allows each module to specialize in one aspect of relationship detection, improving overall precision while maintaining manageable system complexity through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system introduces new parameters (preceding degree, similarity degree, surprise degree) that transform the traditional binary presence/absence detection into a multi-dimensional continuous assessment. By calculating these parameters and using them to filter and rank relationships, the system can precisely identify unexpected preceding relationships that conventional methods miss, while the parameterized approach keeps the system structure organized and manageable.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conventional methods are used, then the system is easy to implement, but relationships useful for future prediction cannot be extracted

Engineering Contradiction:
Improveusefulness for future predictionVSAvoidcomplexity of causality testing
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The surprise degree acts as an intermediary metric that bridges the gap between simple temporal correlation and complex causality prediction. By first identifying relationships with high preceding degree and high surprise degree (indicating unexpected but strong temporal patterns), and then applying causality testing only to these candidates, the system reliably identifies prediction-useful relationships while avoiding the complexity of comprehensive causality testing across all variable pairs.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If all possible relationships are analyzed, then comprehensive coverage is achieved, but computational resources are wasted on obvious relationships

Engineering Contradiction:
Improveaccuracy of relationship identificationVSAvoidcomputational efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

Instead of performing exhaustive analysis on all variable pairs, the system applies partial action by first calculating preceding degree and similarity for all pairs, then using the surprise degree metric to selectively identify only those relationships worth further investigation. This approach achieves high accuracy in identifying unexpected relationships while significantly improving computational efficiency by avoiding wasted resources on obvious or irrelevant relationships.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS20250348507A1Prerequisite relationship extraction device, prerequisite relationship extraction method, and prerequisite relationship extraction program
Publication Date: 2025.11.13 NIPPON TELEGRAPH & TELEPHONE CORP
  • US20250348507A1 patent drawing
  • US20250348507A1 patent drawing
  • US20250348507A1 patent drawing

AI summary

The present invention includes: a preceding degree calculation unit (1) that calculates a degree of preceding of time series data xj of an item j with respect to time series data xi of an item i from a plurality of pieces of data; a similarity calculation unit (2) that calculates a semantic similarity between the time series data xi and the time series data xj; a surprise degree calculation unit (3) that calculates a degree of surprise indicating surprise of combining the item i and the item j on the basis of the degree of preceding and the semantic similarity; a causality testing unit (4) that tests causality of the item i and the item j; and a presentation unit (5) that presents the degree of surprise and presence or absence of the causality.