Pattern Determination Device for High-Dimensional Clustering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing clustering techniques face challenges in determining similarities between patterns, especially in high-dimensional spaces, due to instability caused by the 'curse of dimensionality' and the impact of missing values and outliers, which affects recognition accuracy and robustness.

Innovation Solution

A pattern determination device and method that computes internal probabilities based on a probability density distribution to assess dissimilarities between patterns, using the logarithm of product probabilities for each component, which ensures that missing values contribute minimally and outliers have reduced influence, thereby stabilizing neighbor determination and improving clustering robustness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional distance metrics (L2 norm) are used in high-dimensional space, then neighbor determination can be performed, but recognition accuracy deteriorates due to spherical surface concentration phenomenon

Engineering Contradiction:
Improveneighbor determination accuracyVSAvoidperformance in high-dimensional space
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the parameter of distance metric from conventional L2 norm to L1/k norm (where k≥2). This parameter change fundamentally alters how distances are calculated in high-dimensional space, preventing spherical surface concentration and maintaining stable neighbor determination. The L1/k norm transforms the distance calculation to be more robust in high dimensions, directly resolving the contradiction between maintaining accuracy and adapting to high-dimensional spaces.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If data pre-processing is performed to remove noises, then clustering performance can be improved, but it becomes difficult to handle cases where features are partly missed or outliers cannot be easily identified

Engineering Contradiction:
Improveclustering performanceVSAvoiddifficulty of noise removal
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent converts the harmful effect of outliers and missing values into a beneficial feature by using the L1/k norm. This metric inherently reduces the influence of large deviations (outliers) and handles missing values gracefully, eliminating the need for complex pre-processing. The harm of noisy data is transformed into a robustness advantage, resolving the contradiction between improving reliability and reducing complexity.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If L1 norm is used to enhance robustness against outliers, then robustness improves, but neighbor determination accuracy in high-dimensional space deteriorates

Engineering Contradiction:
Improverobustness against outliersVSAvoidneighbor determination accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent introduces a new parameter k (where k≥2) to modify the L1 norm, creating the L1/k norm. This parameter adjustment fine-tunes the balance between robustness and accuracy: the norm power 1/k reduces outlier influence more gently than standard L1, maintaining better neighbor determination accuracy in high-dimensional spaces while preserving robustness against outliers.

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If dimension reduction techniques are applied, then the curse of dimensionality can be avoided, but features suitable for pattern recognition may not be selected

Engineering Contradiction:
Improveability to handle high-dimensional dataVSAvoidpattern recognition accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

Instead of reducing dimensions, the patent changes the distance metric parameter to L1/k norm, allowing direct operation in the original high-dimensional space. This parameter change preserves all original features while making the distance calculation suitable for high dimensions, avoiding information loss from dimension reduction while maintaining computational feasibility.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS8560488B2Pattern determination devices, methods, and programs
Publication Date: 2013.10.15 NEC CORP
  • US8560488B2 patent drawing
  • US8560488B2 patent drawing
  • US8560488B2 patent drawing

AI summary

A pattern determination device has probability computation means and dissimilarity decision means. The probability computation means computes an internal probability that is a probability in which a value of a predetermined component of a pattern that takes place according to a probability density distribution in a domain of an input pattern falls in a range between the value of said predetermined component of a pattern X (1) and the value of said predetermined component of a pattern X(2). The dissimilarity decision means decides a dissimilarity between said pattern X (1) and said pattern X (2) based on said internal probability computed by said probability computation means.