Questions tagged [terminology]
For questions about the definition or meaning of terms used within Operations Research. Do not use this tag for questions about notation.
33
questions
0
votes
0
answers
16
views
What is the official terminology concerning different types of racks?
Thanks to a previous question, I know about this PDF file, containing a lot of terms concerning supply chain management.
This list is quite elaborated, but I'm now more specifically looking for ...
- 121
2
votes
1
answer
60
views
Does this kind of "partition" have a name?
Consider a convex polyhedron $A$. Assume we have subsets $A_1,\ldots,A_n$ of $A$ that are themselves covex polyhedra and are mutually disjoint except maybe sharing an edge, and that their union gives $...
- 123
2
votes
2
answers
136
views
How do you pronounce MILP? [closed]
Apologies for the english question, but I believe this forum will be better suited for answering my question.
I am trying to decide whether I should use A MILP or An MILP, as I have seen both cases in ...
- 516
2
votes
2
answers
91
views
Is there a name for this type of integer programming?
Let $x_i$ be a decision variable, and let $c_i$ be the coefficient for the decision variable $x_i$.
An integer programming problem is where the goal is to:
$\text{maximize} \quad \sum_i c_ix_i$
$\text{...
- 133
4
votes
1
answer
292
views
Endowment of an agent
I was going through the Shapley-Folkman-Starr Lemma (https://simons.berkeley.edu/sites/default/files/docs/3605/simons2.pdf) and I came across the term "endowment" of an agent.
My assumption ...
- 111
2
votes
1
answer
74
views
What is a transport order in supply chain management?
I arrived at this site as a result of this question.
Last week, two colleagues were having a discussion about the term "Transport Order" in supply chain management. (Is it a recursive ...
- 121
3
votes
2
answers
251
views
Related to Lagrangian dual
In my research class our professor discuss a paper wherein the solution is obtained via a Lagrangian duality. The original problem is given below:
minimize $t$
subject to $\sum_{j \in \mathcal{M_i}}\...
- 33
2
votes
2
answers
65
views
Is there a concept of shrinking the consideration set?
I don't know the terminology, so the title can be confusing.
Let me explain here.
We would like to find the optimal solution in $S$. Suppose some external theory suggests that there must be an ...
- 163
3
votes
0
answers
88
views
What is the general name (e.g. facility location problem) for this problem (if any)?
I would like to know if there is a general name for the following problem:
We will open several facilities. Each facility has an associated facility type. There exists a given number of facility ...
- 135
9
votes
2
answers
772
views
"Partial" Lagrangian Dual in LP
Consider the optimization problem
\begin{align}\label{opt-lp}\tag{Primal}
\begin{array}{cl}
\underset{x \in \mathbb{R}^n}{\text{minimize}} & c^\top x \\
\text{subject to} & Ax = a \\
& Bx =...
- 3,796
3
votes
2
answers
134
views
Defining multiple constraints compactly where some index combinations are not defined
My question is about how usual/strange defining constraints compactly can be (in a scientific document). Formally, I define constraints
$$f_{i,j,k}(x) \leq 0, \quad \forall i \in [I], \ \forall j \in [...
- 3,796
8
votes
1
answer
179
views
Name for this ILP problem type
I am considering automating testing of down-stream testing of packages that depend on other packages. There are test sets $T_1,\ ..., T_n$ which can be tested or not tested, which each have a time ...
- 3,928
2
votes
2
answers
230
views
Best way to solve a optimization problem with no objective function?
I have a MILP but fixed the objective function, so at each iteration is constant.Therefore, I solve a constraint satisfaction problem.
Is there an algorithm to solve this kind of problem fast? I have ...
- 423
3
votes
2
answers
143
views
Scheduling of planned orders while respecting certain stock levels
I am searching for the academic name of the problem of computing a valid schedule for planned order. More precisely, The problem consists of: list of orders O, available vehicle per day K, and the ...
- 119
6
votes
3
answers
2k
views
Is a mathematical programming problem with no objective function an optimization problem?
I have a "mathematical programming" (MP) problem that does not have an objective function. Namely, I want to find a vector that satisfies all constraints (no optimization involved, right?). ...
- 91
7
votes
4
answers
1k
views
What's the name of a finite-capacity bin packing problem trying to minimize the weight of the heaviest bin?
I have a fixed number of bins which are themselves weightless. Each bin can hold only a fixed amount of weight. Not all bins have the same capacity.
I also have a fixed number of objects each of which ...
- 543
3
votes
1
answer
189
views
Logical / combinatorial Benders Decomposition vs Cutting plane method
Is there a difference between logical and combinatorial Benders Decomposition and the cutting plane method?
My understanding is that for all of these techniques, there is a MIP and based on solutions ...
- 2,401
4
votes
1
answer
76
views
Does the facility layout problem with zero and one matrices have a specific name?
I have an facility layout problem where the flow between any two departments is either zero or one. Also the distance between each location pair has the same nature (zero or one). I am curious whether ...
- 425
5
votes
1
answer
135
views
Combined arc capacity constraints in network flows
Consider the network flow polyhedron for a directed graph $G = (N, A)$. Along with the standard flow-balance and single-arc capacity constraints, we are faced with additional constraints which enforce ...
- 1,779
4
votes
1
answer
62
views
What is the name of the graph where any edge is part of a cycle?
I wonder if there is a special category for this kind of graphs, I am thinking of a bidirectional graph but it would also be interesting in the cases when it is undirected.
I am thinking of something ...
- 95
6
votes
1
answer
92
views
Terminology for continuous planning, real-time planning, non-disruptive replanning, overconstrained planning, backup planning etc
In the past 14 years, when dealing with enterprise planning challenges, I've encountered multiple challenges of "repeated planning" and "planning agility" in general. At some point,...
- 4,645
2
votes
0
answers
78
views
Analysis model vs. executable implementation of model?
In my post-graduate research and subsequent career in operational analysis, the difference between following seems to have become clearer with the years: (1) a model of a problem or operations in the ...
- 193
6
votes
2
answers
185
views
What is the definition for an integer-friendly constraint?
I have seen some papers claiming that their proposed model is integer-friendly. I would like to get more information about what type of constraints we can call integer-friendly.
Probably, it can be ...
- 2,064
4
votes
1
answer
611
views
What is the meaning of monotone hazard rate (MHR) distribution?
It might be somewhat irrelevant to this forum but I think that many people here are familiar with this concept. I have seen that many papers assume that customers' valuation ($F$) is a monotone hazard ...
- 2,140
16
votes
2
answers
2k
views
Dual bounds of integer programming problems
I often read in papers when branch-and-X algorithms are used to solve mixed integer programming problems, that the lower bound (in the minimization case) obtained from solving a linear programming ...
- 1,103
8
votes
3
answers
508
views
Difference between "Optimization" and "Constrained Optimization"?
(Another OR noob question)
As I'm trying to learn about OR and Optimization methods for work, I'm having a hard time understanding the difference between "Optimization" and "Constrained Optimization"...
- 2,059
10
votes
2
answers
453
views
Geometric programming: Why are the constraints defined to be less than/equal to 1?
In a simple convex optimisation problem, the standard form is given by \begin{align}\min_{\bf x}&\qquad f({\bf x})\\\text{s.t.}&\qquad g_i({\bf x})\le 0,\quad i=1,\cdots,m\\&\qquad h_j({\...
- 5,271
15
votes
2
answers
2k
views
Polyhedra, Polyhedron, Polytopes and Polygon
About Polyhedra, Polyhedron, Polytopes and Polygon, what do they mean in the context of linear programming and what is the difference between them?
- 7,271
22
votes
4
answers
3k
views
What is a solution?
Consider a standard optimization problem: Minimize an objective function with respect to constraints. My question is:
What does the term "solution of the optimization problem" mean?
At first I ...
- 381
31
votes
5
answers
4k
views
Optimization terminology: "Exact" v. "Approximate"
In optimization literature, I frequently see solution methods termed "exact" or "approximate". (I use the term "method" here because I suspect exactness, or its lack, is a function of both algorithm ...
- 35.5k
37
votes
1
answer
1k
views
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 ...
- 5,982
15
votes
1
answer
1k
views
What is quadratization?
In the context of discrete optimization, what exactly does it mean to "quadratize" a function?
The term seems to be used mainly by operations researchers, in my experience.
- 1,264
15
votes
1
answer
238
views
Has the expressibility of 'non-integrality testing' as extension to MILP been studied before?
It turns out that extending MILP with any of the constraints $y=\lfloor x\rfloor$, $y=\lceil x\rceil$, $0 < x$, or $x\notin \mathbb{Z}$ is 'equally hard'.
(see my answer here, and below)
...
- 1,472