Cross-Validation Data Subsetting for Time-Series Model Training

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Solution Overview

Problem

Current time series forecasting models require significant computational resources and retraining frequency, often resulting in inefficient use of data and potential degradation in model accuracy due to the use of entire datasets for training, especially when data exhibits little to no fluctuation or change.

Innovation Solution

Implement a system that dynamically selects an optimal subset of training data for machine learning models, utilizing a scheduler and cross-validation module to determine necessary retraining based on error thresholds, reducing unnecessary computations and focusing on data that provides value for learning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the entire dataset is used for training the model in each cross-validation fold, then the model training is comprehensive and robust, but the computational resources are significantly consumed and the training process becomes inefficient

Engineering Contradiction:
Improvemodel training robustnessVSAvoidcomputational resource consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent segments the training dataset into multiple subsets (e.g., first subset and second subset) that can be independently evaluated. Instead of training on the entire dataset for each fold, the system trains on one subset, evaluates performance, and determines whether additional subsets are needed based on performance thresholds and data characteristics like stationarity detection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies partial action by training on only a portion of the available data when the data exhibits stationarity or when performance thresholds are already met. The cross-validation process dynamically adjusts the amount of data used for training, avoiding unnecessary training on excessive data that would not improve model performance.

Inventive Principle:
Principle #16Partial or excessive action

2Reliability

If the model is retrained regularly on the entire dataset, then the model stays updated and relevant, but the resource consumption increases significantly and training time is wasted

Engineering Contradiction:
Improvemodel relevanceVSAvoidtraining time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements dynamic retraining decisions based on real-time assessment of data characteristics and model performance. The system monitors whether the time series data exhibits stationarity and whether performance improvements are achieved from additional training, dynamically adjusting the retraining frequency and data scope rather than following a fixed regular schedule.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The cross-validation process provides feedback on model performance and data characteristics to determine whether retraining is necessary. The system evaluates performance metrics after each training iteration and uses this feedback to decide whether to continue training or stop, avoiding unnecessary retraining cycles that would waste time and resources.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If cross-validation is performed on all folds of data, then the model evaluation is thorough and accurate, but the process becomes inefficient when data shows no significant structural changes

Engineering Contradiction:
Improvemodel evaluation accuracyVSAvoidevaluation efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system performs preliminary analysis of the time series data to detect stationarity and structural changes before conducting full cross-validation. By pre-assessing data characteristics, the system can determine whether comprehensive cross-validation is necessary or whether a simplified evaluation approach would suffice, improving efficiency without sacrificing necessary evaluation accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the evaluation parameters dynamically based on data characteristics. When data is detected to be stationary or when performance thresholds are met, the system adjusts the cross-validation parameters to reduce the number of folds evaluated or the complexity of evaluation, thereby improving productivity while maintaining adequate measurement precision.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS20250021866A1Optimized cross-validation for time-series model
Publication Date: 2025.01.16 SAP SE
  • US20250021866A1 patent drawing
  • US20250021866A1 patent drawing
  • US20250021866A1 patent drawing

AI summary

Provided are systems and methods which optimize a validation process performed during training of a time-series forecasting model. The optimization can remove training data that has poor attributes for training (e.g., less error, less fluctuation, less patterns, etc.) to improve the quality of the training data and reduce the amount of processing that is performed by the host system. In one example, a method may include storing a plurality of machine learning models and a data set, dividing the data set into k folds of data, training the plurality of machine learning models on a subset of folds from among the k folds of data, determining error values for the plurality of machine learning models, respectively, based on fold errors among the subset of folds, and storing the error values within the storage.