Questions tagged [operations-research]
uses mathematical and statistical methods to improve efficiency
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Approach for Warehouse Delivery Optimization Problem? [closed]
I have an optimization problem for the delivery of boxes between warehouse and production lines within a small facility. I need to determine how many transport vehicles to buy and which/how many ...
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What is the approximate distribution of the distance between gas stations along a highway?
Thinking it should be exponential, but I could be wrong.
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Case study question on profit optimization
A famous restaurant selling burgers has closely studied the demand for burgers for past months including the times the customer requested a burger and it was already sold out. Further analysis
of data ...
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Estimating Joint Probability from limited data
This is probably a broad question but I am interested in getting the Joint PDF for n random variables each of which can take integer values within a finite range.
I have data in the form of time ...
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0
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Python implementation of standard Expectation maximization algorithm to estimate position bias in LTR
Is there any Python implementation that would allow to use logs data of clicks and their ranking, and return and estimate of relative position bias as discussed in section ...
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1
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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 ...
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Can I use xboost as objective function in an optimization problem?
I am working on a marketing optimization problem, where the goal is maximize profit by optimally allocating spend to different products. Constraint is getting at least 1 Million revenue.
As a first ...
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What methods exist to identify the optimal splits in some exogenous variable, such that a dependent variable is maximized?
I've come across an interesting problem recently, and I'm wondering if I'm missing some obvious approach here. The problem statement is thus:
Imagine I run an online business, and I'm interested in ...
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What are differences between industrial statistics and social science statistics/econometrics that are potential stumbling blocks?
Main question up front: what are differences between econometrics/social science statistics that and industrial statistics that people switching between the two should be are of?
I got a PhD in ...
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49
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Statistical approach for football competition
There are 10 teams in a club.
Each week, there are 3 games where each team plays another team from the same club.
All games are played in the same park. The park has 5 pitches. There are 5 teams that ...
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Where can I learn the math behind how airlines dynamically price tickets?
It's easy to think of factors that airlines take into account, and how the price will vary over time. There are no shortage of articles or medium posts about that. But how can I frame this as a ...
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Visualising Gantt chart distribution
I perform $n$ simulations of operations planning. I can plot a gantt chart for each simulation, but I am interested in visualising the variability of the whole simulation set : I want a Gantt ...
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Bayesian genetic algorithms?
I'm not sure that "Bayesian genetic algorithms" is a real term or even a concept in research. For a while now, I've preferred genetic algorithms as my go-to heuristic optimization technique, ...
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How to derive a conclusion with the scatterplot that we made using the data in a quantitative research? [closed]
How can we write the result section by using the scatter plot that we made using the data in a quantitative research. Also most importantly if the scatter plot shows no correlation.
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Survival analysis with unobserved right censoring
Assume we have a tire shop and would like to build a survival curve for the lifetime of our tires.Once we know how long our tires are useful, we can send push notifications prompting customers to get ...
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QR Factorization to Solve Least Squares Without Using an Inverse
I'm playing around with different ways to solve least squares, and am using numpy to derive values for $\beta$ in a regression problem.
I know that if you do a $QR$ factorization of $X$ such that $...
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1
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Simulating a queue in R [closed]
It's noted that the number of folks in a stationary system will maintain an average equal to the rate of arrival multiplied by the mean of the service distribution.
Where the formula $L = \lambda$ ...
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Formulating a mixed integer programming problem with a binary maximization term
Real-world description of the problem:
In the US, funding for school lunch programs is given to local school districts by the Federal government. If >=40% of students in a school or group of schools ...
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Student-Teacher matching problem
The problem I want to solve is as follows: I have data about how many teaching hours different students spend with their teacher in order to pass their exams. The teaching varies from 25-55 hours. In ...
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How to handle real-world (soft) constraints in an optimization problem? [closed]
I am working on a problem which involves optimizing for minimum power consumption in a large compressor network interconnected through pipelines (think of a connected graph with nodes as compressors ...
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1
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qualitative data in data envelopment analysis (DEA)
I wish to use qualitative input to calculate efficiency using DEA model. For that I based the input on certain questions which were answered on 1-5 rating scale. each input has 5 such questions(...
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Which optimization algorithm applies better for this production problem? Cost minimization
This is a cost minimization problem, where I have to plan the development of a field and the installation of some machines there.
Rectangles A,B,C,D represent production areas, that can overlap. I ...
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1
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How many people at any given time
I have been tasked with finding out approximately how many people were in a location at a given time. I know how many people arrived per hour and how many people left per hour and the average time ...
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185
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Assignment Problem (Linear Programming, Genetic Algorithm, etc.)
I'm looking for advice on how I should approach a specific problem. Some background first:
The problem is about shipments falling into a bin. There are 19 such bins, which are further sorted into 20 ...
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1
answer
401
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Monte Carlo simulation--Have I applied Bernoulli distribution properly? [closed]
I am trying to run a monte carlo simulation and I just wanted to make sure that I set it up properly.
A salesman visits 100 different homes. Someone answers the door 80% of the time. Of that ...
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Sample size human sciences [closed]
I will apply a questionnaire with 90 questions about the possible requests: very bad, bad, neutral, good and very good, the answers will be categorized into 8 different groups. Subsequently the data ...
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Office Desk Rota Assignment problem
This is not a home work and the question is not related to studies (I am not a student). I have to do the weekly desk rota at the office and thought this forum might help with suggestions. My problem ...
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Is this a contextual bandit problem?
I have an operations research problem that I would like to solve but I am unsure what the correct framework for analyzing it would be. The closest I've come across so far is contextual bandits I ...
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How can we decompose generalization gap as done in the paper "Generalization in Deep Learning"?
I am reading a recent paper "Generalization in Deep Learning" and I am unable to understand a step. In this step, they first take neural network as a direct acyclic graph(DAG) and described output of ...
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How to deal with NaN when they make up 45% of the data?
I compare two countries (Germany and Sweden) and have 30 variables over 15 (2001-2016) years. Unfortunately, the first years (2001-2007) for Sewden and (2001-2006) for Germany have NaN (missing values)...
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Design of experiment: Is there correlation between performance vs. employee attrition?
Background:
Assume company X has a cyber security incident team. One of their key performance/risk indicators is how fast they triage the security incidents. For the past 2 quarters, COO observed ...
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stochastic inventory question
Does anyone have any references for inventory optimization? By optimizing I mean going from supplier to the allocation to the store.
I am doing research as to how to optimize any given inventory ...
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What is the difference between the Poisson distribution and the uniform distribution?
I'm modeling a factory with orders arriving independently of each other. I need a series of actual time stamps of arrivals. I've been told that everyone uses the Poisson distribution to model arrivals....
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Does anyone here knows this variable? No one had ever answer this yet in all sites I've been. [duplicate]
what does "W" represents there in the equation 2?
no one had ever answer this yet in all sites I've been.
here is the source.
http://www.scirp.org/journal/PaperInformation.aspx?PaperID=65933
user166388
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What concepts in optimization do I need for machine learning?
I am a Math/CS dual major. As part of my math major, I have the option of taking optimization and mathematical programming classes. I am also interested in machine learning. I know that a lot of ...
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Discrete optimisation of a gym workout routine
I am working on the following problem, which I would like to solve using an elegant optimisation method (both because the answer is genuinely useful to me, and because I am interested in the maths of ...
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If the mean is equal to the standard deviation, what is the general likelihood that the underlying distribution is normal vs exponential?
This comes from operations analysis. Often you have measurement of times, such as time between customers arriving at a store (e.g. Starbucks) or time it takes to process an order (e.g. a cappuccino).
...
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Why do Statistics, Machine learning and Operations research stand out as separate entities
It seems nowadays people who work in ${\bf Statistics, \ Machine\ Learning \ and \ Operations\ research }$ all consider themselves as working in data analytics.
These three categories try to ...
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How to optimize call center call times?
I have been asked to develop a predictive model to optimize call times from a call center. We have historical data on successful calls, date/time, member-specific attributes, etc.
Ideally, the output ...
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Comparing coefficients to understand the change in impact of a variable
Our success measure (satisfaction) have dropped in July compared to June. I want to understand the factors that affected the drop. Since I could not create a flag that identify records that ...
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effect of linear term on quadratic programming
What's the impact of linear term ($d$) on quadratic programming problem ($P$) described as follows
\begin{align*}
\min_x d^T x + 1/2 x^T D x\\
\text{such that }A^T x \geq x_0
\end{align*}
where $D$ ...
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What type of test / research design is recommended for this analysis
It is assumed that people are not seeking for help when they need to, therefore a program is implemented to teach them when to seek help. People can join the program voluntarily. I would like to study ...
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Reverse Code for Factor Analysis
I have done my survey, and now I need to do the data analysis. However, I am not sure whether or not I need to do the reverse code at the first step before I can do the remaining analysis.
There are ...
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Modeling worker performance parameters for optimum allocation of tasks to workers
Lets say we have an English to French translation task in a company and there are 100s of workers who are proficient in doing this task but each worker has its own unique attributes which allow them ...
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Sample size for clinical research
I determined the sample size already (25), but I want to know if it has to be increased because of a minor change. Our study consists of two groups - one will be sedated and the other will not. For ...
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online bin packing and machine learning
I am trying to optimize scheduling disk allocation in data centers. In nature it is an online bin packing problem. But, since each customer has it's own behavior or kind of workload I was wondering, ...
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A YouTube View Estimator [closed]
Here's a thought experiment that I can't come up with a good answer for.
Imagine you have 5 YouTube videos that you want to reach 50,000 views (10,000 views per video) by the 10th day after ...
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Constrained assignment problem (Linear Programming, Genetic Algorithm, etc...)
I'm looking for advice on how I should approach a specific problem. I have about 1000 shops that I have to assign to about 20 different supply centers out of a possible 28, and I'm trying to pick the ...
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What is a good model for revenue managment / price optimization problem
I am trying to create a dynamic pricing model to optimize revenue for a hypothetical business. Lets say I have an application that connects dog walkers to people who want to pay for their dog to get ...
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Scheduling Algorithm for a multi-server queue problem
I have 4 servers, n customers and m reports. At any time, a customer may request one of m reports. There are only 4 servers which are capable of generating reports. Each server can only process one ...
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