Associative storage and associative storing method

• US 5,937,432 A
• Filed: 02/26/1997
• Issued: 08/10/1999
• Est. Priority Date: 02/26/1996
• Status: Expired due to Term

• Current Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Original Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Inventors: Okamoto, Hiroshi, Yamaguchi, Isao, Ichikawa, Kazuhisa
• Primary Examiner(s): Cabeca, John W.
• Assistant Examiner(s): BATAILLE, PIERRE MICHE
• Application Number:
  US08/806,937
• Time in Patent Office: 895 Days
• Field of Search: 711/128, 711/154, 711/100, 706/25, 706/23, 706/27, 706/18, 365/49
• US Class Current: 711/154
• CPC Class Codes: G06N 3/044 Recurrent networks, e.g. Hopfield networks

Abstract

An associative storage includes: a plurality of storage elements having at least one internal signal outputting element for outputting an internal outputting signal toward another storage element and at least one internal signal inputting element for receiving an internal inputting signal outputted form another storage element, a learning signal inputting element for each respective storage element for inputting a learning signal thereto, a recalling signal inputting element for each respective storage element for inputting a recalling signal thereto, an internal state switching element for each respective storage element for turning an internal state of the respective storage element to an ON state when either the learning signal or the recalling signal is inputted thereto and/or the sum of the internal inputting signals exceeds a threshold value while the internal state is kept in an OFF state, wherein the internal state switching element outputs the internal signal towards another storage element when the internal state is turned ON, and an enhancing element for each respective internal signal inputting element for enhancing a signal transmitting efficiency thereof when the internal state of the storage element is turned ON and the internal signal inputting element receives the inputting signal from another storage element.

Claims

1. An associative storage comprising:

a plurality of storage elements, each of said plurality of storage elements having at least one internal signal outputting element for outputting an internal outputting signal toward another of said plurality of storage elements and at least one internal signal inputting element for receiving at least one internal inputting signal outputted from another of said plurality of storage elements;

a learning signal inputting element for each respective storage element for inputting a learning signal thereto;

a recalling signal inputting element for each respective storage element for inputting a recalling signal thereto;

an internal state switching element for each respective storage element for turning an internal state of said respective storage element to an ON state when either the learning signal or the recalling signal is inputted thereto and/or a sum of the at least one internal inputting signal exceeds a threshold value while the internal state is kept in an OFF state, wherein the associative storage element outputs an internal outputting signal toward another of said plurality of storage elements when the internal state is turned ON; and

an enhancing element for the at least one internal signal inputting element for enhancing a signal transmitting efficiency thereof when the internal state of the storage element is turned ON and the at least one internal signal inputting element receives the at least one internal inputting signal from another storage element.

2. The associative storage of claim 1, wherein the enhancing element enhances the signal transmitting efficiency by a constant amount with the inputting of the learning signal.

3. The associative storage of claim 1, wherein the enhancing element enhances the signal transmitting efficiency using the equation:

space="preserve" listing-type="equation">ω

(t)=ω

(t-1)+Δ

ω

wherein ω

(t) is the signal transmitting efficiency at time t, ω

(t-1) is the signal transmitting efficiency at time t-1, and Δ

ω

is a change in the signal transmitting efficiency.

4. The associative storage of claim 3, wherein Δ

ω

is set in proportion to ω

(t-1).

5. The associative storage of claim 3, wherein when ω

(t-1) is large, Δ

ω

is small and when ω

(t-1) is small, Δ

ω

is large.

6. The associative storage of claim 1, wherein the internal state switching element comprises an OR circuit, the learning signal inputting element comprises a first terminal of the OR circuit and the recalling signal inputting element comprises a second terminal of the OR circuit.

7. The associative storage of claim 6, wherein the internal state switching element further comprises a multiplier, an adder and a level detector, and

wherein the at least one internal inputting signal received from the at least one internal signal inputting element is input to the multiplier which multiplies the at least one internal inputting signal by the signal transmitting efficiency, the multiplied at least one internal inputting signal being input to the adder which adds the multiplied at least one internal inputting signal to generate an output signal, and the level detector classifies the output signal into one of a plurality of levels.

8. The associative storage of claim 7, wherein the output from the OR circuit is provided to another of the plurality of storage elements and also to the enhancing element to update the signal transmitting efficiency used by the multiplier.

9. An associative storage comprising:

a learning signal inputting element for inputting a learning signal;

a recalling signal inputting element for inputting a recalling signal;

a plurality of storage elements, each storage element having at least one internal signal outputting element for outputting an internal outputting signal toward another of said plurality of storage elements and at least one internal signal inputting element for receiving at least one internal inputting signal outputted from another of said plurality of storage elements;

an internal state switching element for each respective storage element for turning an internal state of the respective storage element to an ON state when either the learning signal from the learning signal inputting element or the recalling signal from the recalling signal inputting element is inputted thereto and/or a sum of the at least one internal inputting signal exceeds a threshold value while the internal state is kept in an OFF state, wherein the associative storage element outputs the internal outputting signal toward another of said plurality of storage elements when the internal state is turned ON; and

an enhancing element for the at least one internal signal inputting element for enhancing a signal transmitting efficiency thereof when the internal state of the storage element is turned ON and the at least one internal signal inputting element receives the at least one inputting signal from another storage element.

10. The associative storage of claim 9, wherein the enhancing element enhances the signal transmitting efficiency using the equation:

space="preserve" listing-type="equation">ω

(t)=ω

(t-1)+Δ

ω

wherein ω

(t) is the signal transmitting efficiency at time t, ω

(t-1) is the signal transmitting efficiency at time t-1, and Δ

ω

is a change in the signal transmitting efficiency, and

wherein when ω

(t-1) is large, Δ

ω

is small and when ω

(t-1) is small, Δ

ω

is large.

11. The associative storage of claim 9, wherein the internal state switching element comprises an OR circuit, a multiplier, an adder and a level detector, the learning signal inputting element comprises a first terminal of the OR circuit and the recalling signal inputting element comprises a second terminal of the OR circuit, and

wherein the at least one internal inputting signal received from the at least one internal signal inputting element is input to the multiplier which multiplies the at least one internal inputting signal by the signal transmitting efficiency,

the multiplied at least one internal inputting signal being input to the adder which adds the multiplied at least one internal inputting signal to generate an output signal,

the level detector classifies the output signal into one of a plurality of levels, and

wherein the output from the OR circuit is provided to another of the plurality of storage elements and also to the enhancing element to update the signal transmitting efficiency used by the multiplier.

12. A first associative storage element coupled to a second associative storage element, said first associative storage element comprising:

at least one internal signal outputting element for outputting an internal outputting signal toward the second storage element;

at least one internal signal inputting element for receiving at least one internal inputting signal;

a learning signal inputting element for inputting a learning signal thereto;

a recalling signal inputting element for inputting a recalling signal thereto;

an internal state switching element for turning an internal state of the first associative storage element to an ON state when either the learning signal or the recalling signal is inputted thereto and/or a sum of the at least one internal inputting signals exceeds a threshold value while the internal state is kept in an OFF state, wherein the associative storage element outputs the internal outputting signal toward the second associative storage element when the internal state is turned ON; and

an enhancing element for enhancing a signal transmitting efficiency of a respective internal signal inputting element when the internal state of the first associative storage element is turned ON and the internal signal inputting element receives the at least one internal inputting signal.

13. The associative storage of claim 12, wherein the enhancing element enhances the signal transmitting efficiency using the equation:

space="preserve" listing-type="equation">ω

(t)=ω

(t-1)+Δ

ω

wherein ω

(t) is the transmitting efficiency at time t, ω

(t-1) is the transmitting efficiency at time t-1, and Δ

ω

is a change in the transmitting efficiency, and

wherein when ω

(t-1) is large, Δ

ω

is small and when ω

(t-1) is small, Δ

ω

is large.

14. The associative storage of claim 12, wherein the internal state switching element comprises an OR circuit, a multiplier, an adder and a level detector, the learning signal inputting element comprises a first terminal of the OR circuit and the recalling signal inputting element comprises a second terminal of the OR circuit, and

wherein the at least one internal inputting signal received from the at least one internal signal inputting element is input to the multiplier which multiplies the at least one internal inputting signal by the signal transmitting efficiency, the multiplied at least one internal inputting signal being input to the adder which adds the multiplied at least one internal inputting signal to generate an output signal, and the level detector classifies the output signal into one of a plurality of levels.

15. An associative storing method comprising the steps of:

inputting a learning signal to at least two of a plurality of storage elements,

turning respective storage elements to an ON-state in response to the storage elements having received the inputted learning signal, wherein said respective storage elements are always turned to the ON-state when the learning signal is received by the respective storage elements;

exchanging a plurality of internal signals among storage elements of the plurality of storage elements in response to the turning ON of respective storage elements; and

enhancing a signal transmitting efficiency of respective internal signals in response to the exchanging of the internal signals, wherein the enhancing step is only performed when the respective storage element is turned to an ON state and receives at least one internal signal of the plurality of internal signals, from another of the plurality of storage elements.

16. An associative storing method comprising the steps of:

inputting a learning signal to at least two of a plurality of storage elements,

turning respective storage elements to an ON-state in response to the storage elements having received the inputted learning signal, wherein said respective storage elements are always turned to the ON-state when the learning signal is received by the respective storage elements;

exchanging a plurality of internal signals among storage elements of the plurality of storage elements in response to the turning ON of respective storage elements;

enhancing a signal transmitting efficiency of respective internal signals in response to the exchanging of the internal signals;

inputting a recalling signal to at least one of the plurality of storage elements;

turning the at least one storage element to an ON-state in response to the inputting of the recalling signal;

outputting at least one internal signal of the plurality of internal signals, toward another storage element in response to the ON-state of the at least one storage element; and

turning ON said another storage element in response to receiving the at least one internal signal when the at least one internal signal exceeds a threshold value, wherein the step of enhancing is performed for respective storage elements only when the storage element is turned ON and receives at least one internal signal of the plurality of internal signals, from another storage element.

17. An associative recalling method comprising the steps of:

inputting a recalling signal to at least one of a plurality of storage elements storing associative memories;

turning the at least one of the plurality of storage elements to an ON-state in response to receiving the inputted recalling signal wherein the at least one of the plurality of storage elements is always turned to an ON-state when the recalling signal is received;

outputting an internal signal toward another storage element of the plurality of storage elements in response to the ON-state of the at least one storage element;

turning ON said another storage element in response to the internal signal when the internal signal exceeds a threshold value;

inputting a learning signal to at least two of the plurality of storage elements;

turning respective storage elements to an ON-state in response to the inputting of the learning signal;

exchanging a plurality of internal signals among storage elements of the plurality of storage elements in response to the turning ON of respective storage elements; and

enhancing a signal transmitting efficiency of respective storage elements when the storage elements are turned ON and receive at least one internal signal of the plurality of internal signals, from another storage element.