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6 votes
0 answers
104 views

Knotted Traveling Salesperson route

Let us consider fixed points in space, if we apply the well-known Traveling Salesperson Problem algorithm, we get the shortest route. It can give a nontrivial knot in the three-space. The question is ...
knotMJ's user avatar
  • 121
3 votes
1 answer
262 views

What is known about this TSP variant?

Euclidian (planar) TSP asks for a tour with the minimum total length. The problem is known to be NP-hard. I am interested in the variant of finding a closed tour with the minimum enclosed area (...
Mohammad Al-Turkistany's user avatar
3 votes
0 answers
87 views

Additional symmetries of the Traveling Salesman Polytope

Given the complete graph $K_n=(V,E)$, the Traveling Salesman Polytope is a convex polytope in $\Bbb R^E$ obtained as the convex hull of the indicator vectors of (edge-sets of) Hamiltonian cycles in $...
M. Winter's user avatar
  • 13.6k
3 votes
0 answers
145 views

Hamiltonian cycle polytope for the hypercube graph

Let $Q_n$ denote the $n$ dimensional hypercube graph (i.e., graph formed from the vertices and edges of an n-dimensional hypercube). Denote the set of edges and vertices of $Q_n$ by $E_n$ and $V_n$ ...
Ozzy's user avatar
  • 393
2 votes
2 answers
163 views

References for geometric properties of optimal Euclidean traveling salesman tour

Consider a finite set of points $V \subseteq \mathbb{R}^2 $ as a TSP-instance under the standard $\| \cdot \|_2$ norm. (TSP stands for traveling salesman tour.) We know that every optimal TSP tour $T$ ...
mc.math's user avatar
  • 29
2 votes
1 answer
139 views

Description of Linear Time Algorithm for TSP in Halin Graphs

I am looking for a description of the linear time algorithm for the TSP in Halin graphs, that was given in "G. Cornuejols, D. Naddef, and W.R. Pulleyblank. Halin graphs and the travelling ...
Manfred Weis's user avatar
  • 13.2k
2 votes
0 answers
119 views

Corporate salesman problem

A salesman is employed by a large corporation. He has a $n$ cities to visit, connected by roads, forming a graph. But as travel takes a lot of time, he has to pick hotels between visits. He cannot ...
kakaz's user avatar
  • 1,626
1 vote
1 answer
82 views

Do we really need degree constraints for ILP formulations of TSP problems

The Dantzig-Fulkerson ILP-formulation of the symmetric TSP is $$\min\sum\limits_{i=1}^{n-1}\sum\limits_{j=i+1}^n c_{ij}x_{\lbrace i,j\rbrace}\quad\text{s.t.}\\ \sum\limits_{j\ne i,\,j=1}^n x_{\lbrace ...
Manfred Weis's user avatar
  • 13.2k
1 vote
1 answer
115 views

$\mathrm{LP}$ formulation for $\mathrm{k}$-$\operatorname{opt}$ moves

$\mathrm{k}$-$\operatorname{opt}$ moves are an idea to improve non-optimal Hamilton cycles in weighted symmetric graphs by exchanging $\mathrm{k}$ tour-edges with $\mathrm{k}$ edges that do not belong ...
Manfred Weis's user avatar
  • 13.2k
0 votes
1 answer
117 views

Traveling salesperson problem algorithm [closed]

I was wondering something, let's say in a symmetric distance matrix of a sample of TSP, there was a sure algorithm that could remove between 30% to 80% of the values (distances) that wouldn't ...
Ehsan Javanbakht's user avatar
0 votes
0 answers
26 views

Monotony of enforced subtour merging

Is it true that for a symmetric TSP instance in the sequence of edges generated by successively: calculating the optimal 2-factor adding cardinality constraints on the edgesets of the 2-factor's ...
Manfred Weis's user avatar
  • 13.2k
0 votes
0 answers
40 views

Subtour-gluing constraints for ILP formulation of TSPs

If one doesn't want to introduce additional variables to the ILP of a TSP instance, one has to add exponentially many so-called subtour-elimination constraints; in practical calculations subtour-...
Manfred Weis's user avatar
  • 13.2k
0 votes
1 answer
54 views

Relation of 1-trees to optimal tours

Question: given a complete symmetric graph $G(V,E)$ with $n$ vertices and edges $e_{ij}$ having weight $\omega_{ij}$, does there always exists a vector of vertex potentials $(\pi_1,\,\dots,\,\pi_n)$ ...
Manfred Weis's user avatar
  • 13.2k