Operations Research Stack Exchange
Operations Research Stack Exchange

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1500 questions
62
votes
11 answers

Counter-intuitive results in OR

When teaching introductory OR courses I have often found that presenting counter-intuitive or paradox-like results is a great eye-opener for the students. I use these examples and results as a motivation for why we need to learn OR techniques. One…
Sune
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15 answers

Are Python and Julia used for optimization in industry?

I am giving a small computer exercise that aims at teaching students the basics of a modelling language to model small optimization problems. So far I have been using the modelling language GAMS as this is used in many companies in industry. To be…
PeterBe
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51
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8 answers

Great Unsolved Problems in O.R

More than 10 years ago, there was during an INFORMS annual meeting a session dedicated to “Great Unsolved Problems in O.R.” (you can find a small report of that session on this webpage). Which are nowadays the most important open problems in O.R.…
Stefano Gualandi
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50
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8 answers

Optimization Problem Libraries

Can someone please make a list of optimization problem libraries so that the community can add to and refine it? I know a few off the top of my head.
Mark L. Stone
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45
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12 answers

Are there any OR challenges that are similar to Kaggle's competitions?

I am looking for previous OR challenges. My goal is : Applying my knowledge while solving problems suggested in those competitions; and/or If possible, reading solutions posted by participants. I learned a lot about machine learning (ML) by…
Antarctica
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41
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11 answers

Machine learning and operations research projects

Can someone give me some suggestions for projects that use both machine learning/deep learning and operations research to solve business problems? Background: I am a student in OR and I am learning ML/DL on my own, I will graduate next year. My…
Antarctica
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41
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3 answers

How to select a Constraint Programming Solver

I would like to clarify that I am absolutely not an expert when it comes to constraint programming (I happen to use it when it seems to be the right tool for the right job). It is my understanding that the possibility to use global constraints can…
Renaud M.
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41
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10 answers

Are there any COVID-19 (coronavirus) related optimization problems with input datasets that we can "crowd solve"?

Is anyone aware of a medicine/vaccine related challenges with a good problem definition and some available input datasets, ideally related to COVID-19? What kind of constraint solving challenges would that be? Protein folding? If there are any such…
Geoffrey De Smet
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40
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1 answer

What are common and not so common abbreviations in Operations Research?

Many abbreviations are used in Operations Research. For example, we have abbreviations for problem classes (LP, MIP), solution methods (IPM), and specific problems (TSP, VRP). Which abbreviations are commonly used by the Operations Research…
Kevin Dalmeijer
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39
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9 answers

What are the reasons OR industry projects fail?

You probably have done some OR projects within the industry or - if you are in academia - for the industry. I'm wondering if you've seen some patterns of why such projects fail (or at least do not meet the clients requirements). Surely, there might…
JakobS
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38
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8 answers

Why is the programming code of many algorithms not public in the OR community?

In recent years, a huge number of scholars in AI and ML community are using Python to develop their algorithms and then publishing their papers and codes in GitHub. This provides an opportunity for others to work on that paper and develop more…
Amin
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37
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3 answers

How to linearize the product of two binary variables?

Suppose we have two binary variables $x$ and $y$. How can we linearize the product $xy$?
Michiel uit het Broek
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36
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2 answers

How to linearize the product of a binary and a non-negative continuous variable?

Suppose we have a binary variable $x$ and a non-negative continuous variable $y$. How can we linearize the product $x y$?
Michiel uit het Broek
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34
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6 answers

Where can I find open source LP solvers?

I'm familiar with COIN-OR and have also used a couple packages in R to solve LPs. Today I found out Google has their own open source optimization software, and it got me wondering what other open source LP solvers are out there?
Zohar Strinka
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33
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6 answers

How to determine the correct level of detail when modelling?

"All models are wrong, but some are useful" - George E. P. Box I usually work on what one could call operational problems. There I usually do not have too much trouble figuring out the level of detail needed for a model to provide value. However,…
Renaud M.
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