Thank you sooo much Sergiy, I'm currently studying in germany and my Professor could'nt explain it half as understandable as you in 1 hour of time! You saved me a lot of nerves!
@AsadAli-tb7hy
3 жыл бұрын
This is probably the best video on this topic. Such a difficult topic is made so easy.
@ameyamunagekar3795
2 жыл бұрын
Fantastic explanation! The example really helped. Thank you!
@konstantinkuchenmeister1400
3 жыл бұрын
Best video on this topic!
@danielmaia9336
2 жыл бұрын
Thank you! From Brazil!
@fatiheee1996
2 жыл бұрын
Thank you my man!
@Snowmanver2
2 жыл бұрын
Thank you for the video!
@miikenaeko
3 жыл бұрын
I am an undergraduate student in Japan. I am doing my own research on this issue. I wish I could have seen this wonderful video in my own language.
@sergiybutenko
3 жыл бұрын
You should record one!
@blendmeister
2 жыл бұрын
Excellent video, it would great if you could extend it by doing a video on branch and price or even branch price and cut. Thanks!
@the_presenter5602
Жыл бұрын
Best Explanation
@pakwidi531
7 ай бұрын
Thank you sir.
@user-sz6ll4fn1d
2 ай бұрын
legend!
@jameszack7158
2 жыл бұрын
Can column generation method only be used by computer software or can a person use this method on paper to solve LP problems?
@Mattykkk25
Жыл бұрын
Can you offer this in an excel sheet w solving formula?
@HUARASTACA
Жыл бұрын
i would like to see a CODE to find all the useful patterns and their waste
@tanvirkaisar7245
Жыл бұрын
hello Professor, thank you so much for the great explanation! I have some questions, I would be grateful if you could take the time to answer them. 1. @28:00 Since you enumerated all the patterns, and used those patterns to see which pattern gives you the highest objective of CGSP, does not that defeat the whole purpose of not relying on storing the whole matrix A? 2. @35:13, should not we drop the exiting basic variable from the RMP? otherwise, at each iteration the RMP will get larger, which means A will keep growing?
@sergiybutenko
Жыл бұрын
1. Yes, you are right; in this toy example this is done for illustration purposes, since the complete LP is small enough to show it entirely. 2. You could do that, but that (keeping only basic variables in the RMP) would be one of the two extremes, the other one being keeping all the columns introduced in the process. In the first extreme case you may end up spending more time on solving the subproblem, whereas in the second one the RMP may become too large. In practice one usually tries to balance between the two extremes (say, drop a nonbasic column from the RMP if it does not reenter the basis for a certain number of iterations).
@tanvirkaisar7245
Жыл бұрын
Thanks a ton!!
@nagihanbostan2023
3 жыл бұрын
Thanks for video :) What is the C matrix and z used in the equation.
@sergiybutenko
3 жыл бұрын
You mean vector c? Check this video: kzitem.info/news/bejne/sneInq6qoYOqo5g
@nagihanbostan2023
3 жыл бұрын
@@sergiybutenko Thanks a lot.
@nagihanbostan2023
3 жыл бұрын
@@sergiybutenko When I change the number of cuts (80, 50, 100) when I look at probabilities with a maximum of 3 waste, the number of pieces does not integer in the equation. Is it because my solution of the equation is wrong or because these probabilities are not enough for each number of pieces? do i have to look at more probabilities.
@sergiybutenko
3 жыл бұрын
We do not impose the integrality constraints in this formulation, so you can get non-integer solutions.
@abdulrahman-cb9uo
2 жыл бұрын
sir i have a question, do u have code Column Generation for the Cutting Stock Problem for matlab?
@apprentice5271
6 ай бұрын
Hi thanks for the lesson! I have a question. What happens if the solution of the CGSP is not a pattern of the problem. Suppose you solve the CGSP with knapsack and the solution is not one of your column.
@sergiybutenko
6 ай бұрын
The solution to the CGSP must be a feasible pattern, by design.
@hayataatafay3668
2 жыл бұрын
what if we have more than 3 lengths, is there a way to determinate the pattern?
@sergiybutenko
2 жыл бұрын
Yes, the process of determining the feasible patterns would pretty much be the same.
@kamillebidan8410
Жыл бұрын
Can the number of columns being used actively increase? If the number of columns increases to 4, then matrix B would be a 4*3 matrix and it would be impossible to inverse?
@sergiybutenko
Жыл бұрын
Matrix B contains only the columns corresponding to basic variables.
@lopyus
2 жыл бұрын
15:55 how did you say that optimal dual solution is y=c_B^{T} B^{-1}? Why substituting c_B^{T} B^{-1} with y is useful? Thank you
@lopyus
2 жыл бұрын
Nevermind, I think you mentioned it somewhere in your Dual Simplex video. Anyways, thanks for uploading this great course!
@harunyucel354
3 жыл бұрын
Will you consider to give online live training/courses. I would like to take because i have questions and need to understand also 2D cut and stock problems.
@sergiybutenko
3 жыл бұрын
You should come to Texas A&M and take the class :).
@harunyucel354
3 жыл бұрын
@@sergiybutenko Thanks for you reply. and woow it is long way :))) Hello from Turkiye :) I need to understand this type of question for my thesis and i am really struggling- suffering :) In youtube you are the only one , explain fluent and detailed but i have missing part in basic knowledge about integer linear programming. Now i am watching other videos of you to figure out dual problems. I think you used duality in this example. (at least you can give such small trick :D:D )
@sergiybutenko
3 жыл бұрын
@@harunyucel354 yes, definitely study the duality material. Best of luck with your studies!
@harunyucel354
3 жыл бұрын
@@sergiybutenko Sir , i handled 1D cutting stock problem.Thanks for you help via video. At final calculation i used excel solver and got good results. Thanks again. But now i need to understand 2D cut and stock problems. Cutting of rectangular stock plate in identical rectangular small pieces. Do you have any suggestion about this problem. Where should i start ? Do you have any idea about such problems ? Thanks in advance.
@s.butenko
3 жыл бұрын
@@harunyucel354 There is a universal method, called Feynman Problem-Solving Algorithm. Check it out :).
@mrkunalgoswami2010
2 жыл бұрын
is it Gilmore-Gomory model ?
@sergiybutenko
2 жыл бұрын
Yes, the idea was originally proposed by Gilmore and Gomory in 1961.
@RayRay-yt5pe
Жыл бұрын
What I do not like is you dancing in between notations without telling us what they mean. Otherwise great video.
Пікірлер: 45