Combinatorial Optimization Using Evolutionary Algorithm and QUBO Conversion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for expressing combinatorial optimization problems, including array searches, in the QUBO format lead to increased calculation costs due to the need to search all possible combinations and formulate constraints, which reduces flexibility and increases problem scale.

Innovation Solution

The proposed solution involves using an evolutionary algorithm to optimize order information for a combinatorial optimization process that includes an array search, converting this information into a QUBO format, and performing combinatorial optimization using an Ising machine, thereby separating the optimization problem into order optimization and combinatorial optimization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If combinatorial optimization problems including array searches are expressed in QUBO format, then the problem can be solved using standard optimization methods, but the calculation cost increases and the problem scale expands

Engineering Contradiction:
Improveease of formulationVSAvoidproblem scale
Core Design Contradiction:
Ease of manufactureVSQuantity of substance

Solution Approach 1:

The patent segments the combinatorial optimization problem into two distinct parts: array search (handled by evolutionary algorithms) and combination search (handled by QUBO formulation). This segmentation allows each part to be optimized independently, reducing the overall problem scale that needs to be expressed in QUBO format while maintaining solution quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the array search component from the combinatorial optimization problem and handles it separately using evolutionary algorithms. This extraction removes the array search portion from the QUBO formulation, thereby reducing the problem scale and calculation cost associated with expressing the entire problem in QUBO format.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If all possible combinations are searched in QUBO format, then complete optimization is achieved, but the calculation cost increases

Engineering Contradiction:
Improveoptimization completenessVSAvoidcalculation cost
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent divides the search space into two segments: array configurations (explored via evolutionary algorithms with evaluation at each generation) and combinations (explored via QUBO optimization). This segmentation allows the system to achieve complete optimization by searching both segments, while reducing calculation cost by handling each segment with appropriately optimized methods rather than exhaustively searching all possible combinations in QUBO format.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary action by using evolutionary algorithms to evaluate individuals and update evaluation values as generations progress. This preliminary evaluation identifies promising solutions before the final QUBO optimization, reducing the need to exhaustively search all combinations while maintaining optimization completeness.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If array search is included in QUBO formulation, then the problem is fully captured, but the time and effort for formulation increases

Engineering Contradiction:
Improveproblem coverageVSAvoidformulation time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent extracts the array search component from the QUBO formulation and handles it separately using evolutionary algorithms. This extraction significantly reduces the formulation time and effort required for QUBO while maintaining full problem coverage, as the evolutionary algorithms naturally handle array search without requiring explicit QUBO constraints.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the problem into array search (handled by evolutionary algorithms) and combination search (handled by QUBO). This segmentation allows each segment to be formulated with appropriate methods, reducing the overall formulation time while maintaining adaptability and versatility of the approach.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS12282770B2Storage medium, arithmetic operation method, and information processing apparatus
Publication Date: 2025.04.22 FUJITSU LTD
  • US12282770B2 patent drawing
  • US12282770B2 patent drawing
  • US12282770B2 patent drawing

AI summary

A non-transitory computer-readable storage medium storing an arithmetic operation program that causes at least one computer to execute a process, the process includes searching for first order information such that an evaluation value is updated as a generation progresses by using an evolutionary algorithm for a first individual that is a target of a combinatorial optimization process which includes an array search, the individual including the first order information; generating a first array by using the first order information; converting the first array into a QUBO format; and searching for a combination by using the converted first array.