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Questions tagged [operations-research]

Operations Research is the application of quantitative techniques to decision making, typically involving mathematical optimization. Problems include dynamic programming, linear programming and Integer programming & discrete optimization.

Operations Research is the application of quantitative techniques to decision making, typically involving mathematical optimization. A problem is modeled as a math formulation, and the solution obtained via a solver. Problems in OR include dynamic programming, linear programming and Integer programming and discrete optimization.

The other names for Operations Research (OR) include Decision Science, Management Science, or Operational Research.

The Wikipedia page on Operations Research. INFORMS, the society for OR practitioners has a lot of relevant information.

192 questions
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Optimal combination of linked-buckets

Let's say I have the following (always binary) options: import numpy as np a=np.array([1, 1, 0, 0, 1, 1, 1]) b=np.array([1, 1, 0, 0, 1, 0, 1]) c=np.array([1, 0, 0, 1, 0, 0, 0]) d=np.array([1, 0, 1, 1, 0, 0, 0]) And I want to find the optimal…
GooJ
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Why is this simulated annealing algorithm applied to the TSP not converging?

For an exercise I have to find the optimal solution to this Travelling Salesman Problem, only difference is that the salesman may not visit the first coordinate twice. The optimum should lie around 1200 which is given. I don't see why this wouldn't…
Max
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Setting up linear program for allocation/assignment problem

I have some troubles regarding a linear program I alreday solved and use excel but now i want to do it in r/python beacuse I already reach excels and the solvers limits. Therefore I am asking for help on this specific topic. I tried it with the…
rued
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How to solve a TSP using Concorde?

I have 12 nodes and distance between every pair of nodes (in meters). The nodes refer to different streets in a city. I need to obtain an exact solution of the TSP (not heuristic) so I'd like to solve the TSP problem with the program Concorde, but I…
ollie
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Can there be multiple parents AND multiple roots for a Directed Acyclic Graph?

Can there be multiple parents and/or multiple roots for a DAG?
f0331
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combination and simulation using java or excel

I am facing a problem in my project. I have different types of controller that provide different input and output ports. I have the number of required points. I need some code that generate the number of controllers and types depending on the…
kamil abou jaoude
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Nonnegative deviation variables in AMPL

I'm using AMPL and need to input my model that has nonnegative deviation variables (s+ - s-). An example constraint is: (x - 5) = (s+ - s-)
user1816907
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Pyomo and Gekko pricing values differs from Excel

I am trying to get the same result than Excel using 2 python solvers : Gekko and Pyomo. This is a non linear pricing model from the Practical_Management Science (Christian Albright)book, page 350. The solution provided by Excel is to sell my item…
harmonius cool
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Map to a Trans capacity request from transit(Nodal) points using pandas dataframes

Input Dataframe With TerminalID,TName,XY cordinate, PeopleID import pandas as pd data = { 'TerminalID': ['5','21','21','2','21','2','5','22','22','22','2','32','41','41','42','50','50'], 'TName':…
vinsent paramanantham
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Criteria evaluation for cluster generation in R

The code below finds the "optimal" number of clusters. In the example below, the result was 2 clusters. Quickly explaining the code: first, the Ideal Point is calculated, which has the minimum breadth of coverage and the maximum waste production…
Antonio
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Schedule non-overlapping tasks between two people

I am using Google OR-Tools to solve a maintenance scheduling problem. I have five machines which are all initially broken. I need to schedule tasks for two technicians to fix the machines to minimize the total lost output. Each technicial can fix…
EDK
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Google OR-Tools: Total Time Capacity over All Routes Combined

In Google OR-Tools Java, how do you set a dimension capacity over all routes combined? My use case is for the total duration of all routes—-there can only be X hours of travel for the entire fleet of vehicles. I see documentation online for how to…
davidjf
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MIP (ompr) model taking too much time to solve in R

I am trying to solve a capacitated facility location problem in R. The sample data for that: n<- 500 #number of customers m<- 20 #number of facility centers set.seed(1234) fixedcost <- round(runif(m, min=5000, max=10000)) warehouse_locations <-…
Shibaprasadb
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How do I make clusters based on a fixed capacity of each cluster in R?

So I have a dataset with 600 points, their latitude, longitude, and demands. I have to make clusters such that for each cluster the points will be near each other and the total capacity of that cluster will not exceed a certain limit. A sample…
Shibaprasadb
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Is there a clever way to get rid of these loops using numpy?

I'm reaching the maximum recursion depth and I've been trying to use np.tensordot() I couldn't really get an insight into how to use it in this case. def stopping_condtion(a,V,V_old,eps): return np.max(la.norm(V - V_old)) < ((1 - a) * eps) /…
Max
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