Feasibility Pump Algorithm for Mixed-Integer Programming

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Solution Overview

Problem

Mixed-integer programming algorithms, such as the feasibility pump, often suffer from cycling issues that lead to fast convergence to local optima, necessitating the need for improved methods to escape local minima and find global optima efficiently.

Innovation Solution

Embedding feasibility pump techniques within a Monte Carlo simulation framework, specifically using simulated annealing, to proactively randomize the search space and guide the solution towards the global optimum, utilizing FPGA or ASIC hardware for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the feasibility pump algorithm is used to solve mixed-integer programming problems, then the algorithm converges quickly to a solution, but it gets trapped in local optima due to cycling issues

Engineering Contradiction:
Improveconvergence speedVSAvoidsolution quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies dynamics by making the perturbation mechanism adaptive rather than static. The algorithm dynamically adjusts the perturbation strategy based on detected cycling patterns, switching between different perturbation techniques (random perturbation, targeted perturbation, and hybrid perturbation) to maintain effectiveness as the search progresses and to escape from local optima.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes parameters by introducing a suite of perturbation parameters that control the search behavior. These include the perturbation probability parameter that controls how often perturbation is applied, and the perturbation magnitude parameter that controls the size of changes made to escape cycling patterns and local optima.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If perturbation techniques are used to escape local minima, then the algorithm can diversify the search space, but the convergence speed decreases due to reactive approach

Engineering Contradiction:
Improveability to escape local optimaVSAvoidconvergence speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by proactively implementing perturbation techniques before the algorithm gets trapped in cycling patterns or local optima. Rather than waiting for cycling to be detected and then reacting, the algorithm preemptively applies perturbation strategies to maintain diversity in the search and prevent stagnation, thereby preserving convergence speed while ensuring reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies periodic action by implementing perturbation at regular intervals during the search process. The algorithm periodically applies perturbation to the current solution to maintain exploration capability, ensuring that the search does not become too greedy and miss potentially better regions of the solution space.

Inventive Principle:
Principle #19Periodic action

3Ease of manufacture

If conventional CMOS hardware is used for solving MIP problems, then the implementation is straightforward, but the solving speed is insufficient for complex problems

Engineering Contradiction:
Improveimplementation simplicityVSAvoidsolving speed
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent applies mechanics substitution by replacing conventional CMOS hardware with alternative computing paradigms. Specifically, the invention implements the feasibility pump algorithm on FPGAs (Field-Programmable Gate Arrays) and ASICs (Application-Specific Integrated Circuits), which provide parallel processing capabilities and customizability that dramatically accelerate the solving of mixed-integer programming problems compared to general-purpose CMOS processors.

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

Data Source

PatentUS11556687B2Method and system for solving mixed-integer programming problems using a feasibility pump technique embedded in a Monte Carlo simulation framework
Publication Date: 2023.01.17 1QB INFORMATION TECHNOLOGIES INC
  • US11556687B2 patent drawing
  • US11556687B2 patent drawing
  • US11556687B2 patent drawing

AI summary

A method and a system are disclosed for solving a mixed-integer programming problem, the method comprising obtaining an indication of a mixed-integer programming optimization problem; until a performance criterion is met: providing the mixed-integer programming optimization problem to an optimization oracle adapted for solving the mixed-integer programming optimization problem using a feasibility pump technique and comprising an optimization solver, initializing parameters of an optimization oracle and an initial solution pair, the parameters comprising Monte-Carlo simulation parameters, a list of neighborhood functions and a measure of fractionality, and performing iterative calls to the optimization solver until a stopping condition is met; and providing at least one corresponding solution obtained from the optimization solver.