Questions tagged [oc.optimization-and-control]
Operations research, linear programming, control theory, systems theory, optimal control, game theory
1,214 questions
0
votes
0
answers
18
views
Solving decoupleable families of FBSDEs
Let $d_1,d_2\in \mathbb{N}_+$, a stopping time $\tau$, and consider a system of BSDEs
\begin{align}
Y_{\tau}^1 & = \xi^1+\int_{t\wedge \tau}^{\tau}\, f_1(t,Y_t^1,Z_t^1,Y_t^2,Z_t^2)dt - \int_{t\...
0
votes
0
answers
102
views
Monotonicity of the convex sum of two binary entropy functions
Let $T$ be some random variable on $[0,1]$, and define
\begin{equation}
\alpha(t) \triangleq \mathbb{E}[T \vert T\le t],\\
\beta(t) \triangleq \mathbb{E}[T \vert T>t], ~t\in[0,1].
\end{equation}
...
0
votes
1
answer
83
views
Donsker-Varadhan duality in conditional sense?
A coherent risk measure named Entropic Value-at-Risk was introduced as follows: Let $(\Omega,\mathcal{F},\mathbf{P})$ be a probability space, $X$ be a random variable and $\beta$ be a positive ...
0
votes
0
answers
51
views
Seeking Efficient Methods for Non-Convex Optimization Problem with Bilinear Term and Sparsity
I am working on a bilinear inverse problem arising in multi-channel signal processing. My problem background is to reconstruct a certain one-dimensional information $\mathbf{w} $ of an object from ...
14
votes
2
answers
783
views
A binomial optimisation problem
Consider a coin that comes up heads with probability $0 < p < \frac{1}{2}$. Fix some integer $N > 0$. We choose in advance a number of flips to run.
Write $H, T$ for the total number of heads ...
1
vote
0
answers
57
views
Comparision theorem for nonlinear integral Volterra equations with parameters
I am looking for comparision results for nonlinear integral Volterra equations with parameters. This was partially motivated by this paper. There, the author establishes, under mild hypothesis, the ...
1
vote
0
answers
140
views
Solving equations on a high dimensional torus
I want to establish some useful criteria for uniqueness of solutions to the following:
$$Mx=b,\\ \text{subject to}\ ||x(2k-1:2k)||=1, k=1,2,\cdots,5,$$ where $M\in\mathbb{R}^{10\times10},\ x\in\mathbb{...
7
votes
1
answer
814
views
Softest transition from 0 to 1 on the real axis in minimum time
We want to get from 0 to 1 on the real axis with a moving point $P(x(t))$, that moves only in the right direction, as soft as possible in a minimum time. We introduce the class $\mathcal{S}$ ...
0
votes
0
answers
118
views
How is the derivative formula in equation (8) of the OptNet paper derived?
I'm studying the OptNet paper (Amos & Kolter, 2017), which integrates quadratic programs (QPs) into neural network layers and enables end-to-end learning through differentiable optimization.
In ...
0
votes
1
answer
208
views
How to design encoders with the minimum number of rows?
Assume that matrices $\mathbf{A}$, $\mathbf{B}$, and $\mathbf{C}=\mathbf{A}\mathbf{B}$ are given. I aim to find matrices $\mathbf{E}_1$, $\mathbf{E}_2$, and $\mathbf{E}_3$ such that
\begin{align}
\...
2
votes
0
answers
145
views
Conjecture regarding the limit optimal transport under cost $\|x-y\|^p$ as $p\to 1^-$
Consider measures $\mu$ and $\nu$ in $\mathbb{R}^d$ with equal mass and no atoms, supported on a compact set, and make additional reasonable assumptions as necessary. Consider the optimal transport ...
0
votes
0
answers
103
views
How much can bounded volatility bias a martingale's moving-average exit?
Let $(W_t)_{t\ge 0}$ be a one-dimensional standard Brownian motion on its natural filtration $(\mathcal{F}_t)$.
For fixed constants
$$0 < \underline{\sigma} < \overline{\sigma} < \infty,$$
...
1
vote
0
answers
62
views
Details on the usage of projective transformations in Karmakar's algorithms
The question is related to this algorithm in linear optimization. In the algorithm, projective transformations are used as said by wikipedia:
Since the actual algorithm is rather complicated, ...
2
votes
1
answer
219
views
Optimization over loop spaces
I posted this question a few days ago to https://or.stackexchange.com/questions/13173/optimization-over-loop-spaces but didn't receive any replies, so I thought I would try here (if this is improper ...
3
votes
0
answers
81
views
Variational problem of minimizing sum of Frobenius norms
I'm stumped by the following variational problem which came up in the course of my research. Let $X_1, X_2 \in \mathbb{R}^{m \times d}$ and $Y_1, Y_2 \in \mathbb{R}^{n \times d}$ be fixed matrices of ...
2
votes
0
answers
96
views
Designing a loss function in the form of a linear combination
I have functions $f : \Bbb{R}^n \to \Bbb{R}_{\geq 0}$ and $g : \Bbb{R}^n \to \Bbb{R}_{\leq 0}$ and would like to find a $\mathbf{x}_* \in \Bbb{R}^n$ where $g(\mathbf{x}_*)=0$ and $f \left( {\bf x}_* \...
4
votes
0
answers
97
views
Use of left-continuous with right-limits processes in singular stochastic control
I am trying to wrap my head around some features of singular stochastic control, and one of the things that has been bothering me is that authors sometimes take the singular control to be left-...
0
votes
1
answer
91
views
Can a total order extend the 1D sort-and-match approach to multidimensional optimal transport?
I’ve been studying the optimal transport problem and I understand that in one dimension it can be solved quite easily: because $\mathbb{R}$ is totally ordered, the cumulative distribution function ...
1
vote
0
answers
168
views
Matching matrix columns under scaling, translation and orthogonal transformation
Given vectors ${\bf p}_1, {\bf p}_2, \dots, {\bf p}_n \in {\Bbb R}^d$ and ${\bf q}_1, {\bf q}_2, \dots, {\bf q}_n \in {\Bbb R}^d$, define the $d \times n$ matrices
$$ {\bf P} := \begin{bmatrix}
...
2
votes
1
answer
272
views
Absolute integrability and Fourier transform
In engineering we are mainly interested in linear time-invariant (LTI) systems which are bounded input, bounded output (BIBO). It's easy to prove that BIBO condition is equivalent to $$\int_{-\infty}^{...
0
votes
0
answers
68
views
Is the norm of the gradient of the Moreau-envelope non-decreasing in $\lambda$?
Let $f$ be an $\rho$-weakly convex function, $f:\mathbb{R}^d\to \mathbb{R}$. The Moreau envelope of $f$, $f_\lambda$ for a parameter $0<\lambda<1/\rho$ is defined as
$$ f_{\lambda}(x) := \min_{y}...
1
vote
0
answers
175
views
Optimal permutation for maximizing sum of minimum absolute differences
Problem Statement
Given a positive integer $n \geq 3$, consider a permutation $\pi = (a_1, a_2, \ldots, a_n)$ of $\{1, 2, \dots, n\}$. For each $i$ ($1 \leq i \leq n-1$), define $d_i$ as the minimum ...
0
votes
0
answers
75
views
Lower bound of the condition number of scaled positive definite matrix
whether we can find postive definite $\{A_k\}$ such that $\frac{\kappa(\lambda_{\max}((I+\alpha D_k)^{-1}(I-\alpha(A_k-D_k))))}{\kappa(A_k)}=\Theta(n)$. Here $A_k\in\mathbb{R}^{n\times n}$ is positive ...
16
votes
1
answer
800
views
Best strategy to reach a half-plane without a compass
I thought of the following problem. Due to its simple and natural formulation, I guess that it must had been already studied, but I could not find any reference. I'm interested in knowing what is the ...
1
vote
1
answer
183
views
Is the tangent cone to the epigraph of a Lipschitz function with existing directional derivatives the epigraph of its directional derivative function?
Let $f : \mathbb{R}^n \to \mathbb{R}$ be a locally Lipschitz function, and let $\bar{x} \in \mathbb{R}^n$. Assume the directional derivative
$$
f'(\bar{x}; v) := \lim_{t \downarrow 0} \frac{f(\bar{x} +...
1
vote
0
answers
198
views
Choosing phases to minimize the $L^\infty$ norm of a trigonometric polynomial
Let $a,\varphi\in \mathbb{R}^N$. Consider the trigonometric polynomial
$$f(\phi;t):=\sum_{n=1}^Na_ne^{i \phi_n} e^{i nt}.$$
My question is: what can be said about the quantity
$$\omega(a)=\inf_{\phi\...
1
vote
0
answers
53
views
Extension of the Ioffe-Tikhomirov theorem to locally Lipschitz functions with the Clarke subdifferential?
More precisely, assume that
$f:X\times Y\to
\mathbb{R} \cup \{+\infty \}$ is a function where $Y\subset X$ is compact,
$\partial_{x}^{C}f\left( x_{0},y\right) $ is the Clarke
subdifferential of at $...
3
votes
1
answer
198
views
How many points can one pack in an $\ell^{\infty}$-box?
Let $n,N\in \mathbb{N}_+$. What is the minimal diameter $r\ge 0$, in $\ell^{\infty}$, of $[0,r]^n$ which there are $N$ points at a pairwise distance of $1$? Specifically, are there known estimates ...
4
votes
2
answers
544
views
How to make this system ergodic?
Consider the following cooperative game played on the circle $S^1$, which we identify with $[0, 1]$ with its endpoints identified.
Let $0 < \alpha < 1$ be an irrational number. A total of $N \...
2
votes
1
answer
113
views
How to control an elliptic PDE with equality integral state constraints?
I was wondering how we can solve this control problem with equality integral constraints:
$$
\min _{y \in K} J(y)=\left\|y-y_d\right\|_{0, \Omega}^2+\|u\|_{0, \Omega}^2
$$
subject to
$$
\left\{\begin{...
3
votes
0
answers
110
views
Which function does this cross section optimize?
I often notice tankers of the type illustrated in the figure below.
The cross section is neither circular nor elliptical. Is it a "notable" geometric shape?
Which function or property does ...
3
votes
1
answer
212
views
Least-squares problem with a rank constraint
Given $n < m < n^2$, fat rank-$m$ matrix ${\bf A} \in {\Bbb R}^{m \times n^2}$ (that has full row rank) and vector ${\bf y} \in {\Bbb R}^m$,
$$\begin{align}
\underset{{\bf X} \in {\Bbb R}^{n \...
5
votes
2
answers
822
views
In Euclidean space, if it's easy to generate random elements of a set, is it also easy to compute the projection to the set?
Let $A \in \mathbb{R}^m$ be some set with the property that it is easy (polynomial-time computation) to generate random elements $r \in A$. Is it then also easy to compute
$$ P_A(x) := \arg \min_{y\in ...
1
vote
0
answers
106
views
Does sequential rank-one approximation (Eckart–Young Theorem) yield a global minimum?
Problem Formulation
Given real values $ z_{i,j}^{(k)} $ for indices
$
i = 1,\ldots, n, \quad j = 1,\ldots, m, \quad k = 1,\ldots, p,
$
our goal is to estimate the parameters $\alpha_{i}^{(k)}$, $\...
1
vote
0
answers
110
views
Points on variety with tangent directions characterized by constraints
Given an (real) algebraic variety
$$ V := \left\{ x \in \mathbb{R}^{n} (\mathbb{C}^{n}) \mid h_{1}(x) = 0, \dots, h_{m}(x) = 0 \right\} $$
where $h_{1},\dots,h_{m} \in \mathbb{R}[x_{1},\dots,x_{n}]$, ...
0
votes
0
answers
74
views
Some kind of scaled convexity
I have the following discrepancy that satisfies this type of inequality. I want to know if this can be related to some kind of weak convexity. If so, what is the name of this property? Additionally, ...
3
votes
2
answers
234
views
A variant of the vertex clique cover problem
Assume that I have a graph $G(V, E)$, where each vertex $v$ is assigned a non-negative weight $w(v) \geq 0$. I aim to find a partition of the graph into cliques $C_1, C_2, \ldots, C_k$ (Here, $k$ is ...
8
votes
0
answers
351
views
Optimal strategy in a selection game
Nate is given a chance to play a game - there are $n \geq 2$ turns. On each turn, he is given a number, uniformly drawn from $[0, 1]$ independent of other draws. On that turn, he may choose to either ...
1
vote
1
answer
148
views
Continuity of Solutions to Linear Programs
Suppose I have a linear program of the form $\max c^Tx$ such that $Ax \leq b$. I am curious as to the continuity of the solutions to such a linear program under perturbations of the entries of $A$.
...
1
vote
1
answer
244
views
Solution to a quadratically constrained quadratic program with unit ball constraint
I am working on a quadratically constrained quadratic program (QCQP) of the form:$$ \min_{x} \quad \frac{1}{2} x^T P x + q^T x + r$$
$$ \text{subject to} \qquad x^{T}x \leq 1 $$
where $P \in S^{++}_{...
5
votes
0
answers
126
views
Rational maps from the circle to the unitary group (energy-preserving convolutive mixtures)
Consider a rational map $A : S^1 \to U(n)$, i.e. a matrix of rational functions such that evaluation at any $z \in S^1 \subset \mathbf C$ is unitary. These objects show up in digital signal processing ...
3
votes
1
answer
359
views
Eigenvalues of Laplace operator and Schrödinger operator
When reading the paper Control for Schrödinger operators on tori by N.Burq and M.Zworski (Math. Res. Lett., 19(2):309–324, 2012), an inequality confused me:
Define the flat torus $\mathbb{T}^2=\mathbb{...
1
vote
0
answers
57
views
Change in active constraints when perturbing the objective of a QP
Suppose I have a quadratic program (with positive semidefinite cost matrix) with affine (polytopic) constraints. It is known that the solution to this is piecewise affine, with the ``pieces'' defined ...
1
vote
0
answers
122
views
How to optimize parametric information-theoretic bounds?
I am faced with an information-theoretic upper bound, such as
\begin{align}
\sqrt{\alpha'}2^{I_\alpha(X;Y)},
\end{align}
where $I_\alpha(X;Y)$ is the Rényi mutual information with parameter $\alpha>...
1
vote
1
answer
81
views
Lower spectral radius of matrices with an invariant subspace
Let $\mathcal{A} = \{ A_1, \ldots, A_J, : A_j \in \mathbb{R}^{s\times s}\}$, and define the lower spectral radius (LSR) (aka joint subradius) by
$LSR(\mathcal{A}) = \lim_{n\rightarrow\infty} \inf_{A_{...
0
votes
1
answer
87
views
Self-concordant barrier for the epigraph of $f(x,y) = x^p y^{1-p}$?
The problem
Assume $p > 1$. Consider the function
$$f(x,y) = x^p y^{1-p}, \qquad x,y > 0.$$
Note that
$$
f'' = p(p-1)x^{p-2}y^{-1-p}
\begin{bmatrix}
y \\ & x
\end{bmatrix}
\begin{bmatrix}
1 &...
0
votes
2
answers
211
views
Optimization algorithms for Kronecker approximation of high-dimensional covariance matrices
I'm working with a high-dimensional covariance matrix and exploring Kronecker product approximations to make it computationally manageable.
Here's the setup:
I have a graph $G$ represented by a $D\...
2
votes
1
answer
139
views
Minimum time required by a curve to reenter a closed ball with radius equal to the reciprocal of its maximum curvature
I have a continuously differentiable curve $r : \mathbb{R} \to \mathbb{R}^{n}$, $n \ge 2$, with the properties
\begin{align}
\lvert r'(t) \rvert = 1 \text{ for all } t \in \mathbb{R}, \\
\lvert r'(t) -...
1
vote
1
answer
401
views
Solving a 0-1 quadratic matrix inequality
I am working on a binary optimization problem. So far I have derived the following constraint functions.
\begin{align}
\begin{bmatrix} \left( P + \sum_{i=1}^n (\sum_{j=1}^n x_{i, j} \alpha_j) e_i e_i^...
8
votes
1
answer
859
views
One flip coin game
Nate has $n \geq 2$ coins $\{C_i\}_{0 \leq i \leq n-1}$ that each turn up heads with probability $\frac{i}{n-1}$ each, but he is not sure which ones are which.
He has \$1 with which to bet with. On ...