Operations Research, sometimes known as Management Science or Decision Science, is the discipline of applying appropriate analytical methods to help those who run organisations make better decisions.
Questions tagged [operations-research]
794 questions
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Travelling Salesman Variation
Is there a name for this variation and a recommended algorithm for solving this problem:
You have a large boat with many leaks on it.
As soon as you patch a leak, it resets, and slowly begins leaking again gradually over time at a higher and…
MineR
- 183
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Stochastic withdrawals from finitely-lived stock
Suppose an energy source has n quanta of energy in storage, all of which are available now (t=0) until t = T, at which time the energy source disappears (or is no longer available). Suppose there are two types of request for energy quanta: one…
Dale Stahl
- 11
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discuss convexity of the following set?
discuss convexity of the following set ?
$$M= \{(x,y)∈\Bbb R^2 : x^2+y^2≥a^2 ,x^2+y^2≤b^2 ,x>0,y>0\} $$
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confusion in forming constraints to the product manufacturaing problem of operations research
In the OR problem statement attached below I am confused about the constraints to this problem.
The constraint on manufacturing is 10 hours of production per day.
so, if x->quantity of product 1 manufactured/day
y->quantity of product 2…
Akansha Banerjee
- 31
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Reddy Mikks new objective formation problem operations research
Am I thinking of the correct solution to the problem attached in Figure below of the Introduction to Operations Research book by Taha? I describe my approach to the problem in the attachment.
x->quantity of exterior paint bought more than 2…
Akansha Banerjee
- 31
- 5
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Crossing the bridge puzzle mathematical solution
I have been trying to understand the mathematical solution to the Operation Research crossing the bridge puzzle. I was reading and trying to understand the solution given in the following…
Akansha Banerjee
- 31
- 5
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2 answers
How to find the minimum $z$?
Solve: Minimize $z = 2x_1 + 3x_2$, such that
$x_1 + x_2 ≤ 4$
$3x_1 + x_2 ≥ 4$
$x_1 + 5x_2 ≥ 4$
and such that $0 ≤ x_1 ≤ 3$, and $0 ≤ x_2 ≤ 3.$
My attempt : From $x_1 + x_2 ≤ 4$ and $3x_1 + x_2 ≥ 4$, i got $x_1=0$ and $x_2=4$ .
From $x_1 + x_2 ≤…
jasmine
- 14,457
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How are linear constraints obtained?
What is the process of writing linear constraints for the following for example?
Let stocks be partitioned by capitalization: large, medium and small.
We are looking for the portfolio to be divided evenly between large and medium cap stocks, and…
Hidaw
- 971
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The LPP below is getting min ratios to be zero or undefined, what do I do?
Z = 2X1 + 3X2 + 10X3
subject to
x1 + 2x3 = 0
x2 + x3 = 1
x1,x2,x3 >= 0
I tried using Artificial Variables and converted into standard LPP but during the 2nd iteration all the min ratios were undefined and zero.
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Objective function increases if the slope is negative
I've been reading through the book "Linear Programming" - A Concise Introduction by Thomas S.Ferguson and I've came across this idea that:
The function $x_1$ + $x_2$ is constant on lines with slope -1, for example the line $x_1$ + $x_2$ = 1, and…
Riccardo A.
- 59
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Branch and bound algorithm
Can someone helps with the following question:
Modify the branch-and-bound algorithm to use Lagrangian bounds instead of linear programming bounds. Discuss the advantages and drawbacks of such an approach.
Mathlb
- 1
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2 answers
How to formulate as an assignment problem?
How will I formulate this problem as an assignment problem?
I really don't know.
By definition of assignment problem, all the variables $x_{ij}$ are binary $(0$ or $1)$ and all the supply and demand are equal to $1.$
Will the 'cost' be represented…
user441848
- 1,658
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AMPL API cplex solution time
I have a MILP model written in AMPL and would like to do some computational experiments. I am using AMPL API for Java for controlling the experiments.
Besides others, I want to record the time that CPLEX uses for computing an LP relaxation. I know…
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Optimal choice of smart phone
Imagine that I am buying a new smartphone. My budget is \$300 and I am concerned with
memory (RAM size).
number of CPU cores.
I searched for different choices and found the maximum size RAM I can get with \$300, without considering the number of…
Mohammad Nur
- 41
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Mathematical reason beetwen two operations
I have spent many hours trying to find out by myself, the following:
Specifically I mean the relationship between dividing a number "n", between p, and getting the root of "n" with an index "p", then what is the algebraic reason between both…
ESCM
- 3,161