# Tag Info

### Why are integer minimax problems hard?

This is going to be a hand-waving argument: perhaps this has been formalized in the literature someplace. I think the issue is that the linear relaxation is in some sense more compatible with the p-...
Accepted

### Why are integer minimax problems hard?

I can see two reasons why branch-and-bound based solvers can have a hard time solving these problems: the linear relaxation may be bad (as stated above); these models have typically (exponentially) ...

### Why are integer minimax problems hard?

I will give you a little more insight based on my latest experience solving minimax (or maximin) integer programs. Sorry I will be a bit self-citing here. Indeed, the main reason that can explain the ...

### Linear facility location problem for large size problems (police station)

You may have a look at our recent work based on Benders decomposition, for the discrete Maximum Coverage Facility Location problem. It works very well if the number of facilities is relatively small, ...
Accepted

### Symmetric undirected $p$-median instance with fractional LP solution?

I think I've found an instance with four nodes and $p = 2$ via brute force (a lot of randomized instances). I've attached my Python script as well. I relaxed the Daskin and Maass (2015) formulation ...

### Linear facility location problem for large size problems (police station)

It sounds like you are describing either the set covering location problem (SCLP) (Wikipedia entry; canonical citation) or the maximal coverage location problem (MCLP) (Wikipedia entry; canonical ...

Accepted

### partitioning hub assignment models

Cost matrixes are discussed in the book: "Assignment Problems" by Rainer Burkard, Mauro Dell'Amico, Silvano Martello (on pages 73, and 200, etc.). Yes, some parts would be unconnected (most ...

### What is the state of the art on the Weber problem?

The Fermat-Weber problem can be formulated as a conic quadratic problem (aka. SOCP). These problems can be solved in polynomial complexity using an interior-point method. See the Mosek modelling ...

I am not a search engine, if you would search for "dynamic facility location problem" you would for example find this book for free. Chapter 15 covers multiple formulations from the ...

### Designing a multi-commodity network flow optimizer

Question 1 You could simply use the priority function as the cost function on the arcs. This way, it is for example cheaper to ship a commodity to $D_1$ from $W_2$ ($1$ unit of cost per unit of flow) ...

### Using Spatial Multi Criteria Analysis for simultaneously locating various facilities?

Although it seems to be late to answer this question (as you need to submit a project until Friday), the following papers can be helpful in determining a solution approach to the multi-facility ...
It sounds like you want to pack $N$ rectangles with given dimensions $w_i \times h_i$ in a $W \times H$ rectangle, as discussed here. To allow each rectangle to be rotated 90 degrees (with dimensions ...