Dependency Network Analysis via Multitask Graphical Lasso

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Solution Overview

Problem

Traditional methods for differential dependency network analysis produce a large number of spurious differences, limiting their usefulness in identifying reliable conclusions between various classes of data, such as brain regions involved in learning and cancer diagnostics.

Innovation Solution

Employing transfer learning techniques to control the precision-recall tradeoff by biasing learned dependency networks to be similar, thereby reducing spurious differences and highlighting true differences supported by the data, using graphical models and parameters like λ1 and λ2 to adjust sparsity and difference detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional independent network learning methods are used, then each dependency network can be learned separately, but a large number of spurious differences are produced

Engineering Contradiction:
Improveease of learning individual networksVSAvoidreliability of detected differences
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent combines multiple independent network learning tasks into a single joint learning framework using the graphical lasso objective function. By sharing the sparsity-inducing L1 penalty across all tasks simultaneously, the method learns multiple dependency networks in an integrated manner that reduces spurious differences while maintaining the ability to capture task-specific variations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a tuning parameter that controls the degree of sparsity sharing across tasks. By adjusting this parameter, users can balance between capturing task-specific differences and reducing spurious differences, allowing flexible control over the trade-off between detecting true differences and maintaining reliability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If sparsity is increased to reduce false positives, then the number of detected differences decreases, but true differences may be missed

Engineering Contradiction:
Improvereliability of detected differencesVSAvoiddetection precision of true differences
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent employs a tunable sparsity parameter within the graphical lasso framework that allows users to control the degree of sparsity applied across all tasks simultaneously. By adjusting this parameter, one can balance between reducing false positives and maintaining detection precision for true differences, avoiding the need to choose extreme sparsity levels.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The joint learning framework provides feedback across tasks through the shared optimization process. The sparsity pattern learned from one task informs the learning of other tasks, allowing the system to adaptively identify which differences are consistent across tasks (likely spurious) and which are task-specific (likely true differences).

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS9449284B2Methods and systems for dependency network analysis using a multitask learning graphical lasso objective function
Publication Date: 2016.09.20 NEC CORP
  • US9449284B2 patent drawing
  • US9449284B2 patent drawing
  • US9449284B2 patent drawing

AI summary

Methods and systems for displaying dependencies within data and illustrating differences between a plurality of data sets are disclosed. In accordance with one such method, a plurality of data sets are received for the generation of a plurality of dependency networks in accordance with a graphical modeling scheme. The method further includes receiving a selection of a value of a parameter that adjusts a number of differences between the dependency networks in accordance with the graphical modeling scheme. In addition, at least one version of the dependency networks is generated based on the selected value of the parameter. Further, the one or more versions of the dependency networks is output to permit a user to analyze distinctions between the dependency networks.