From 5c5052df885a1e678c9624e2a3952e93e166cc3b Mon Sep 17 00:00:00 2001 From: Pedro Maciel Xavier <31925649+pedromxavier@users.noreply.github.com> Date: Mon, 11 Sep 2023 21:38:58 -0300 Subject: [PATCH] Update README.md --- README.md | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/README.md b/README.md index a0310b5..843a4f9 100644 --- a/README.md +++ b/README.md @@ -27,23 +27,27 @@ Recently, significant advances in computing systems and algorithms specialized f These novel tools include Quantum Annealing, Quantum Gate-Circuit Optimization Algorithms (Quantum Optimization Alternating Ansatz, Variational Quantum Eigensolver), other hardware-accelerated platforms, such as Coherent Ising Machines and Simulated Bifurcation Machines, not to mention traditional methods such as Simulated Annealing and Parallel Tempering. -
- Show Math +### Mathematical Model -Mathematically speaking, this kind of optimization problem is defined by models of the form +Conceptually speaking, it is an optimization model with a **quadratic objective function** on **binary variables** and **no constraints**. +Despite being very simple, these models are capable of representing other nonconvex global optimization problems. -$$ +```math \begin{array}{rl} - \min & \alpha \left[\mathbf{x}' Q\,\mathbf{x} + \mathbf{\ell}' \mathbf{x} + \beta \right] \\ - \textrm{s.t.} & \mathbf{x} \in \lbrace{0, 1}\rbrace^{n} + \min & \alpha \left[\mathbf{x}' \mathbf{Q}\,\mathbf{x} + \mathbf{\ell}' \mathbf{x} + \beta \right] \\ + \textrm{s.t.} & \mathbf{x} \in \lbrace{0, 1}\rbrace^{n} \end{array} -$$ +``` -where $\min$ and $\max$ are interchangeable under sign inversion and spin variables $\mathbf{s} \in \lbrace{\pm1}\rbrace^{n}$ may be employed by taking $s = 2x - 1$ as convention. +
+ Show Description -In other words, it is an optimization model with a **quadratic objective function** on **binary variables** and **no constraints**. +Analizing the model attentively, let $\mathbf{x}$ be a **vector of boolean (zero-one) variables**. +Take also the **vector of linear terms** $\mathbf{\ell} \in \mathbb{R}^{n}$ and the **strictly upper triangular matrix of quadratic terms** $\mathbf{Q} \in \mathbb{R}^{n \times n}$. +Last but not least, consider $\alpha, \beta \in \mathbb{R}$ as the **scaling** and **offset** parameters, respectively. -Despite being very simple, these models are capable of representing other nonconvex global optimization problems. +Note that in this kind of problem, $\min$ and $\max$ are interchangeable under sign inversion. +Also, spin variables $\mathbf{s} \in \lbrace{\pm 1}\rbrace^{n}$ may be employed instead, assuming that $s = 2x - 1$ by convention.
@@ -72,7 +76,7 @@ Given the following binary Knapsack Problem one could write a simple [JuMP](https://jump.dev) model and have its constraint automatically encoded by [ToQUBO.jl](https://github.com/psrenergy/ToQUBO.jl).
- Show Code + Show Code ```julia using JuMP