Reservoir Calculation Device for Time-Series Processing

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Solution Overview

Problem

Current deep learning algorithms like RNN and LSTM for time-series data processing require significant computational resources and operation amounts, leading to long training times and high power consumption, necessitating elaborate parameter tuning for high performance.

Innovation Solution

A reservoir calculation device with an input circuit, a reservoir circuit, and an output circuit, where the reservoir circuit includes intermediate circuits with neuron circuits and time constant circuits to generate intermediate signals that undergo transient changes, allowing for efficient processing and representation of feature information in input signals without extensive training.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If RNN or LSTM is used for time-series data processing, then memory representation capability is improved, but operation amount and power consumption increase significantly

Engineering Contradiction:
Improvememory representation capabilityVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The invention segments the neural network training process into two distinct parts: (1) a fixed reservoir network that processes time-series data without training, and (2) only the output layer weights that require training. This segmentation eliminates the need for backpropagation through the entire network, dramatically reducing computational operations and power consumption while maintaining memory representation capabilities.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reservoir network is pre-configured with fixed random weights and structure before processing time-series data. This preliminary setup allows the reservoir to immediately process data with temporal memory capabilities without requiring iterative training, reducing the operation amount during actual data processing.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If RNN or LSTM is used for time-series data processing, then memory representation capability is improved, but training time increases

Engineering Contradiction:
Improvememory representation capabilityVSAvoidtraining time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

By segmenting the network into a fixed reservoir and a trainable output layer, the invention eliminates the need for time-consuming backpropagation through the reservoir, reducing training time to only the output layer weight optimization while preserving temporal memory capabilities.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention extracts the computationally intensive training requirement from the reservoir network and concentrates it only in the output layer. The reservoir itself requires no training, taking out the time-consuming iterative optimization process from the majority of the network while maintaining its memory functions.

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If reservoir computing is used to reduce operation amount, then computational efficiency is improved, but accuracy of weight representation decreases

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidweight accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The invention introduces an intermediary analog multiply accumulator circuit that performs weight calculations in the analog domain, maintaining high precision while enabling efficient parallel processing. This intermediary component bridges the fixed reservoir and output layer, preserving accuracy through precise analog computation before digital conversion.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention replaces digital computation with analog circuit implementation for the reservoir and weight operations. Analog circuits naturally perform multiplication and accumulation operations with high precision and parallelism, improving computational efficiency while maintaining accuracy through physical signal processing rather than discrete digital operations.

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

4Speed

If hardware implementation of reservoir unit is used, then processing speed is improved, but data conversion errors increase

Engineering Contradiction:
Improveprocessing speedVSAvoiddata conversion errors
Core Design Contradiction:
SpeedVSLoss of information

Solution Approach 1:

The invention maintains continuous analog signal processing throughout the reservoir and weight operations, avoiding repeated analog-to-digital and digital-to-analog conversions. This continuity preserves signal integrity and minimizes conversion errors while enabling high-speed parallel processing through analog circuit operations.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The analog multiply accumulator serves as an intermediary that performs precise analog computations and only converts to digital at the final output stage. This single conversion point minimizes data loss compared to multiple conversions, preserving processing speed while reducing conversion errors through careful analog signal management.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS20240143989A1Reservoir calculation device and adjustment method
Publication Date: 2024.05.02 KK TOSHIBA
  • US20240143989A1 patent drawing
  • US20240143989A1 patent drawing
  • US20240143989A1 patent drawing

AI summary

A reservoir calculation device according to an embodiment includes a reservoir circuit and an output circuit. The reservoir circuit receives input data and outputs intermediate signals, each undergoing a transient change when the input data changes. The output circuit outputs an output signal obtained by combining the intermediate signals. The reservoir circuit includes intermediate circuits, each including a neuron circuit and an intermediate output circuit. The neuron circuit generates an intermediate voltage undergoing a transient change corresponding to weight data and the input data when the input data changes. The intermediate output circuit outputs an intermediate signal representing a level of the intermediate voltage from the neuron circuit. The neuron circuit includes a time constant circuit capable of changing a time constant. The time constant circuit is connected between a reference potential and an intermediate terminal outputting the intermediate voltage.