Continuous Embedding Output Layer for Neural Network Decoding

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Solution Overview

Problem

Conventional neural machine translation models are computationally expensive and parameter-heavy due to their reliance on one-hot representations and softmax functions for word outputs, leading to inefficient decoding processes.

Innovation Solution

A machine learning system with a continuous embedding output layer that generates continuous vectors, utilizing a cosine similarity-based loss function to train the model, replacing the softmax layer with a continuous valued embedding table to output word IDs as nearest neighbors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If softmax function with one-hot representations is used for word output, then language generation accuracy is maintained, but computational complexity and parameter count increase significantly

Engineering Contradiction:
Improvelanguage generation accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the output parameter representation from discrete one-hot vectors to continuous vectors. The continuous embedding layer outputs a continuous vector that is then converted to discrete word IDs through nearest neighbor search in the embedding table, replacing the traditional softmax computation over the entire vocabulary.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts only the necessary directional information from the full softmax computation. By using continuous vectors and cosine similarity measurement, the system extracts the essential directional relationship between output and target embeddings without computing probabilities for all vocabulary items.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If softmax layer is used for decoding, then probability distribution over vocabulary is obtained, but decoding speed decreases due to large matrix multiplication

Engineering Contradiction:
Improveprobability distribution accuracyVSAvoiddecoding speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent introduces continuous vectors as an intermediary representation between the neural network output and the discrete word vocabulary. The continuous embedding layer produces continuous vectors that serve as intermediaries, which are then efficiently mapped to word IDs through nearest neighbor search, avoiding direct softmax computation over the vocabulary.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical softmax computation (large matrix multiplication) with a different mechanism: continuous vector generation followed by nearest neighbor search in embedding space. This substitution uses cosine similarity measurement and continuous embedding lookup instead of probabilistic softmax computation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If one-hot representations are used for each word, then precise word identification is achieved, but parameter count and memory usage increase

Engineering Contradiction:
Improveword identification precisionVSAvoidparameter count
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent changes the parameter representation from high-dimensional one-hot vectors to low-dimensional continuous vectors. The continuous embedding layer outputs continuous vectors with fewer dimensions than the vocabulary size, and the embedding table stores dense continuous representations instead of one-hot encodings.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent transitions from the discrete high-dimensional one-hot space to a continuous lower-dimensional embedding space. By representing words as continuous vectors in a compressed dimensional space, the system maintains semantic relationships while reducing the number of parameters required.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS10691901B2Sequence generation using neural networks with continuous outputs
Publication Date: 2020.06.23 CARNEGIE MELLON UNIV
  • US10691901B2 patent drawing
  • US10691901B2 patent drawing
  • US10691901B2 patent drawing

AI summary

A machine learning system including a continuous embedding output layer is provided. Whereas traditional machine language translation or generation models utilize an output layer that include an single output for each word in the output vocabulary V, the present machine learning system includes a continuous embedding output layer that stores continuous vectors mapped to an m-dimensional vector space, where m is less than V. Accordingly, the present machine learning system processes an input string to produce an output vector and then searches for the continuous vector within the vector space that most closely corresponding to the output vector via, for example, a k-nearest neighbor algorithm. The system then outputs the output string corresponding to the determined continuous vector. The present system can be trained utilizing a cosine-based loss function.