2
votes
1answer
94 views
Optimization problem - maximizing number of satisfied linear inequalities subject to a quadratic constraint
I am wondering what is known about optimization problems of the following type.
Our control x is a unit vector in $\mathbb{R}^n$. We are given a finite number of linear inequalit …
0
votes
1answer
39 views
Finding a sub-matrix from a fat matrix with the best condition number.
Given a m-by-n matrix with $n>>m$ and with a known rank of $k\leq m$, what would be a computationally effective way of finding out $k$ columns, such that the matrix formed using th …
6
votes
1answer
163 views
Inverse of a totally unimodular matrix
A unimodular matrix $M$ is a square integer matrix having determinant $+1$ or $−1$.
A totally unimodular matrix (TU matrix) is a matrix for which every square non-singular submatr …
2
votes
1answer
70 views
Maximizing supermodular functions
I have a real supermodular objective function which I want to maximize with constraint. The constraint is on the size, like |A|=k .
I am wondering if anyone can give me more inf …
0
votes
0answers
33 views
Approximation for accumulative set cover
Let $S_1,\ldots,S_m\subseteq U$ be subsets of a set $U$ of size $\lvert U\rvert=n$. Over all permutations $\pi$ of the set $\{1,\ldots,m\}$, I want to maximize the quantity
\begin …
4
votes
3answers
294 views
Selecting $k$ integers from an interval $[0, N]$ to maximize the minimum difference between pairwise sums
I have an optimization problem where I need to select $k$ integers over the interval $[0, N]$ s.t. I maximize the minimum difference between any pairwise sum of the $k$ integers (w …
1
vote
2answers
132 views
sorting two paired lists of real numbers to minimize consecutive absolute differences
Consider a set of $n$ real-valued number pairs: $(x_1,y_1), (x_2,y_2), \dots, (x_n,y_n)$. I want to find a permutation $p$ of the indices which minimizes the sum of consecutive a …
0
votes
0answers
104 views
Chinese Postman problem in bidirected graph
I need to find a Chinese postman circuit in a bidirected graph.
Bidirected graph here is not the symmetric directed graph, but the graph introduced by Edmonds & Johnson in 19 …
0
votes
0answers
50 views
Laplacian using SDP
Is there any suggestion about how could one construct a model that uses semidefinite programming that minimizes sum of k smallest eigenvalues of Laplacian matrix?
I found two paper …
10
votes
1answer
488 views
Lotteries, Turan’s problem, and minimization of risk
Suppose I am a high-volume broker aiming to make some money on a state lottery. In this lottery, six balls are drawn from a population of (let's say) 50, without replacement. A t …
0
votes
1answer
305 views
Finding the lowest cost set of disjoint paths using all nodes in a directed graph?
I have a directed graph with edges connecting nodes representing costs.
I wish to find the set of paths which
-go from node 'start' to node 'end'
-are node-disjoint (except for t …
6
votes
1answer
337 views
How does this algorithmic proof of Edmonds-Gallai work?
Sorry, this is going to be technical and dirty. I am not looking for a proof of the Edmonds-Gallai structure theorem (I understand two of them, even if they are rather similar); I …
0
votes
0answers
88 views
What is known about this constrained maximum s-t-cut problem?
What is known about the following problem?
Problem: Given an undirected, connected, planar graph $(V,E)$ with positive edge weights $q: E \to \mathbb{R}_0^+$, and given two distin …
1
vote
1answer
129 views
set and subset series combinatorics
let $A=\{1,2,3...,N\}$ and $B_1,B_2,B_3\dots,B_n$ be a series of subsets of $A$ which satisfied that $|B_i|=m$,
$|B_i\cap B_j|\le k$. what is the maximum of $n$? ($k< m< N$) …
1
vote
0answers
67 views
Maximum magnitude subset sum
Let $z_1,z_2,\dots,z_N$ be vectors from $\mathbb Z^m$ for some $m$. The problem is:
Given a positive integer $p$, find the subset $A_p \subset \{ 1,2,\dots,N \}$ of size $|A_p| = …

