Gaussian Ranking via Smooth Activation Mapping

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Solution Overview

Problem

Conventional ranking engines face inefficiencies in optimizing rank loss functions due to non-smooth mappings between scores and ranks, leading to long training times and decreased accuracy when using computationally efficient optimization techniques or time-consuming smooth approximations.

Innovation Solution

Implementing a computer-implemented method that uses a matrix factorization model with an activation function providing a smooth mapping between scores and ranks, enabling direct optimization via efficient techniques like stochastic gradient descent without the need for time-consuming smooth approximations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional optimization techniques like stochastic gradient descent are used to optimize rank loss functions, then computational efficiency is improved, but the non-smooth mapping between scores and ranks causes optimization to fail or require unacceptable time

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidoptimization convergence
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces a smooth approximation function as an intermediary between the non-smooth rank loss function and the optimization algorithm. This smooth approximation acts as a mediator that preserves the essential properties of the original rank loss function while providing the smoothness required for efficient gradient-based optimization techniques to converge reliably.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the parameters of the optimization process by using a smooth approximation of the rank loss function instead of the original non-smooth function. This parameter change enables the use of stochastic gradient descent and other efficient optimization techniques that require smooth, differentiable objective functions.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If smooth approximations are used to enable efficient optimization, then computational efficiency is improved, but the mapping accuracy decreases and training time increases

Engineering Contradiction:
Improveoptimization speedVSAvoidranking accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies a smooth approximation that is sufficiently accurate for optimization purposes but not overly complex. This partial approximation provides just enough smoothness to enable efficient optimization while maintaining sufficient accuracy to preserve ranking quality, avoiding the excessive complexity that would degrade accuracy.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent creates a smoothed copy of the rank loss function that preserves the essential characteristics and behavior of the original function. This copied approximation enables efficient optimization while maintaining fidelity to the original ranking objectives, allowing the optimized model to generalize well to unseen data.

Inventive Principle:
Principle #26Copying

3Productivity

If manual development of smooth approximations is performed, then optimization efficiency is improved, but the process becomes time-consuming and complex

Engineering Contradiction:
Improvetraining efficiencyVSAvoidmodel development complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent enables the system to automatically select and apply appropriate smooth approximation techniques without requiring manual intervention. The framework provides built-in mechanisms for choosing smoothing parameters and approximation functions, allowing the training process to self-configure for optimal performance across different scenarios.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent develops a universal smooth approximation framework that can be applied to various ranking scenarios and loss functions. This multi-functional approach provides a general-purpose solution that works across different contexts, eliminating the need for custom manual approximation development for each specific case.

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

Data Source

PatentUS10180968B2Gaussian ranking using matrix factorization
Publication Date: 2019.01.15 NETFLIX INC
  • US10180968B2 patent drawing
  • US10180968B2 patent drawing
  • US10180968B2 patent drawing

AI summary

In one embodiment of the present invention, a training engine teaches a matrix factorization model to rank items for users based on implicit feedback data and a rank loss function. In operation, the training engine approximates a distribution of scores to corresponding ranks as an approximately Gaussian distribution. Based on this distribution, the training engine selects an activation function that smoothly maps between scores and ranks. To train the matrix factorization model, the training engine directly optimizes the rank loss function based on the activation function and implicit feedback data. By contrast, conventional training engines that optimize approximations of the rank loss function are typically less efficient and produce less accurate ranking models.