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14 votes
Accepted

What are the pros and cons of Hexaly (ex LocalSolver)?

Here is a quick summary of the pros and cons of Hexaly (formerly LocalSolver), a global optimization solver combining exact and heuristic techniques. Please note that this summary is written by the ...
Hexaly's user avatar
  • 2,986
13 votes

Implementation gap in logistics

The implementation gap may not be a function of the "quality of the model" (or the algorithm used to solve it, which is a separate dimension). I had an experience with a logistics problem where the ...
prubin's user avatar
  • 39.5k
11 votes

Breakthroughs in Operations Research since 2010

Machine Learning Under a Modern Optimization Lens by Dimitris Bertsimas and Jack Dunn, is a fascinating book in the space of OR & ML. The book provides an original treatment of machine learning (...
VChourasiya's user avatar
11 votes

Breakthroughs in Operations Research since 2010

Hedetniemi conjectured in 1966 that $χ(G×H)=\min\{χ(G),χ(H)\}$ for all graphs $G$ and $H$. Here $G×H$ is the graph with vertex set $V(G)×V(H)$ defined by putting $(x,y)$ and $(x',y')$ adjacent if and ...
Kuifje's user avatar
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10 votes

Implementation gap in logistics

You asked two questions at the end and I only try to answer the second "why is it [implementation gap] not always included anyway": If I understand your question correctly, I'd say there can be many ...
EhsanK's user avatar
  • 5,864
10 votes

Use of machine learning techniques to determine parameter values

You are touching three similar but different subjects in your question. Choosing the set of parameter values for an algorithm and a set of instances is a task known as offline parameter tuning, ...
Alberto Franzin's user avatar
10 votes

Bibliographic databases/search engines

For me, there is no substitute for Google Scholar. The main issue with our field is that it is pretty broad, so it is hard to tell where relevant publications might be. In many cases, the relevant ...
Michael Trick's user avatar
10 votes

Bibliographic databases/search engines

Ultimately, it depends on why you're doing the search. It also depends on what you mean by "coverage" - do you mean you want all papers that can be remotely considered OR/MS, or do you care about ...
HJohns's user avatar
  • 101
10 votes

Breakthroughs in Operations Research since 2010

In terms of the metric TSP, Karlin et al. (2020)1 developed a novel approximation algorithm that beat the infamous Christofides algorithm by a very modest difference of $10^{-36}$! This was a long ...
TheSimpliFire's user avatar
  • 5,412
9 votes

Use of machine learning techniques to determine parameter values

The problem you are referring to is hyper-parameter optimization and a simple search in google will bring up many blogs (and of course) research that has been done in this area. You haven't asked ...
EhsanK's user avatar
  • 5,864
9 votes
Accepted

Status of reinforcement learning for (mixed) integer programming?

Firstly, be ware that "traditional approaches" do not need to be exact. Heuristics are a big thing in OR for decades. Now to answer your question: Reinforcement learning is not state-of-the-...
PeterD's user avatar
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8 votes
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Scheduling problem data generation

It is not ideal, but sometimes I think the best you can do is utilize problem collections from published papers as benchmarks, even if their parameters are rather arbitrary (not necessarily based on ...
prubin's user avatar
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7 votes

Bibliographic databases/search engines

I agree with Dr. Trick that I tend to start with Google Scholar. If I'm looking to see what's been done since a paper was published, I'll often click the "cited by" option. Another option that may be ...
E. Tucker's user avatar
  • 1,317
7 votes

Tips on How to Review Operations Research Literature Effectively?

Not a question, but switching to a reference management software has helped me a lot (Mendeley, in my case, but there are alternatives). In particular, the ability to tag papers with my own keywords, ...
dxb's user avatar
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7 votes

Breakthroughs in Operations Research since 2010

INFORMS recongnizes the best contributions in OR/MS with the Frederick W. Lanchester prize, that is: "The Lanchester prize is awarded for the best contribution to operations research and the ...
Mostafa's user avatar
  • 2,104
6 votes
Accepted

Interplay of OR and Statistics Research

I'm going to interpret "in OR" as appearing in OR journals and/or written by people who identify as OR/MS/IE researchers. I'm a bit familiar with the intersection of optimization and ...
prubin's user avatar
  • 39.5k
6 votes

Is the iteration-limited Simplex dual solution of a MIP node useful?

It is common practice for MIP solvers to solve node LPs (other than at the root node) via dual simplex. I can't say with certainty that they terminate dual simplex prematurely if the objective value ...
prubin's user avatar
  • 39.5k
6 votes

Is the iteration-limited Simplex dual solution of a MIP node useful?

Yes, you can solve the dual and use that as a (weaker) bound than the optimal solution of the LP. This leads to the trade off between faster processing nodes vs processing more nodes. This approach is ...
Sune's user avatar
  • 6,562
6 votes

Tips on How to Review Operations Research Literature Effectively?

The way I discover literature is to identify the key authors & papers in the field I'm interested in. From there on it's just a matter of following the citation trail. The influential authors/...
Nikos Kazazakis's user avatar
6 votes

Breakthroughs in Operations Research since 2010

Quadratization without auxiliary variables For decades, people have been converting arbitrary optimization problems into linear ones, which makes them far easier to solve. With so much recent progress ...
Nike Dattani's user avatar
  • 1,278
6 votes

is there any recommended "rolling horizon in optimization" literature for beginners?

I typically use these images to explain rolling horizons (although I tend to call it continuous planning), for example on employee rostering (but it works just as well on other use cases): I explain ...
Geoffrey De Smet's user avatar
5 votes

How do you keep track of the latest publications in OR

Very interesting notes about different alternatives. IMHO, it is not necessary a real-time or periodic scan of updates. Related to a particular topic you're researching, it may be enough to do a full ...
Agus Montero's user avatar
5 votes

Use of machine learning techniques to determine parameter values

There was a similar question on Cross Validated and as in my comment there, I would look into the use of statistical experimental design, specifically factorial designs and fractional factorial ...
kjetil b halvorsen's user avatar
5 votes

Use of machine learning techniques to determine parameter values

To my understanding, the tuning process you just mentioned is also an learning technique where your training set is your set of representative instances. The problem is with generalization because ...
Ragheb's user avatar
  • 51
5 votes

Scheduling problem data generation

One type of data that is likely to exist in many real-world applications is the so-called "ordered" data. In an ordered setting, if the processing time of a job $j$ is larger than that of another job $...
Mostafa's user avatar
  • 2,104
5 votes

Robust optimization for IP formulation

I think this is a relatively easy but still general paper to start with: https://arxiv.org/pdf/1501.02634.pdf
Bgz6's user avatar
  • 191
4 votes
Accepted

Branch and price with two sets of exponential variables

A common case where you would see 2 or more exponentially large sets of variables, is in: VRPs with heterogeneous vehicles: some vehicles have special equipment or larger capacity and can serve ...
Joris Kinable's user avatar
4 votes
Accepted

Literature on "simcity-like" problems

Your problem looks like a quadratic assignment problem. The problem has been researched since at least the 1950s. As long as P$\neq$NP, there cannot be any constant factor approximation algorithm. I ...
PSLP's user avatar
  • 2,401
4 votes

Scheduling problem data generation

A generator of job-correlated, machine-correlated and mixed-correlated Permutation Flowshop instances is described in Watson et al. (2002)1 and can be found here. From the abstract: We introduce a ...
Alberto Franzin's user avatar
4 votes

Implementation gap in logistics

It's unlikely that you will find a generalised study on this, as the predictive power of an optimisation model depends on the accuracy of the data we use to build the model, and on the skill of the ...
Nikos Kazazakis's user avatar

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