Sir, thank you. This was the only video I could find that clearly explained either-or binary constraints in a way that I could understand and apply to a specific problem in my MBA course. (Ateneo de Manila Graduate School of Business - Manila, Philippines)
@coverCell
4 жыл бұрын
You're welcome! Glad you find it useful.
@dust2dust61
3 жыл бұрын
Thank you sir. This was very helpful. I was banging my head for the past few hours before finding your explanation.
@coverCell
3 жыл бұрын
You're welcome! (I'm glad to hear that this video had saved somebody's head.)
@johndias631
3 жыл бұрын
Very Well explained. Please keep doing this! You are an amazing teacher
@coverCell
3 жыл бұрын
Thank you!! I'm so glad to know that you found the explanation useful. I'll keep doing this, and hopefully will get even better as well :)
@johndias631
3 жыл бұрын
@@coverCell Can you please do a video on using meta heuristics in integer programming?
@coverCell
3 жыл бұрын
@@johndias631 Hello! I haven't got any plan on that yet. Furthermore, I think the metaheuristics application (especially the encoding/decoding) would be very highly dependent on the problem on hand. Let's say the metaheuristic is GA, then the chromosome, crossover procedure, mutation procedure, really depends on the problem (Knapsack problem, scheduling problem, etc.).
@bluetaurean
Жыл бұрын
I am a supply chain professional. I love the simplicity with which you explain and yet make the concepts super clear. Would love to see more videos from you on subject. Also can you recommend good books with real world examples of LP, IP, MILP that can be used to learn in more detail?
@coverCell
Жыл бұрын
Thank you! I think this book Operations Research: Applications and Algorithms (by Wayne L. Winston) is good. It has a lot of examples for practicing LP/IP formulations.
@Dennaton
4 жыл бұрын
Great explanation, thanks a lot!
@coverCell
3 жыл бұрын
You're welcome! Glad you find this video useful.
@Mara51029
Жыл бұрын
Appreciate your excellent video and valuable for the world 😊
@coverCell
Жыл бұрын
Hello! I'm glad you find this valuable, thank you for watching my videos.
@choosewithmeguys
3 жыл бұрын
Thank you so much Sir!
@coverCell
3 жыл бұрын
You're welcome! Thanks for watching my videos.
@defnebaseren5808
3 жыл бұрын
Thanks a lot for this! Super clear explanation!
@coverCell
3 жыл бұрын
You're welcome! I'm glad that the explanation on my video helps.
@divshu2061
3 жыл бұрын
Sir , the video was helpful. I have the following questions. Can there be different formulations for the same constraint. I have come across the constraints for the following : if b=1 then x=y the answer suggested is : y-M(1-b) =0 (Put them in the form as suggested). Then the IP constraints are -x+ y
@divshu2061
3 жыл бұрын
Sir there is another one: x1 2 . The answer suggested is b1 >= (x1 - 2)/M1 and x2 0 , -X1 >=0 resulting in x1
@coverCell
3 жыл бұрын
Hello! First, I think there is a difference between x=y (that is required in the original constraint) and x-y >= 0 (this implies x may be greater than y). Second, the variable y in the video is an indicator 0-1 variable, while in your case y is an actual variable. Therefore, -x+ y
@coverCell
3 жыл бұрын
For the second problem, I think this is correct: x1
@erayerol1629
10 ай бұрын
Thanks!
@coverCell
10 ай бұрын
You're welcome! Thanks for watching my videos.
@farahsouayfane7446
3 жыл бұрын
Thank you for the video, very helpful, In fact, I have an if-then constraint as follow if (Occ)t>0 then T1
@coverCell
3 жыл бұрын
Hello, you're welcome! It seems like you have a step function in your case, I found a suggestion about step function here: math.stackexchange.com/questions/1987271/optimization-technique-for-step-function-in-constraints-and-objective-function However, since (Occ)t > 0, it might be quite difficult to model that due to the sign being strictly larger than.
@hughrhone
2 жыл бұрын
Thanks for your explanation. I have a problem exactly like your if-then example. In my case it's if s5 = 1, s6 = s7 = s8 = 0. How would I implement this in excel? is it s6 + s7 + s8
@coverCell
2 жыл бұрын
Hello! I think if you apply it on Excel, M may be replaced by a very big positive integer. The y is a decision variable, just like your s5, s6, and so on. As for the if-then constraints, as shown in 19:16, you will have s6 + s7 + s8
@rubenstevenaar640
3 жыл бұрын
Great explanation! I've got one question, does it matter which equation you choose to be f(x) or g(x) regarding the either-or constraint?
@coverCell
3 жыл бұрын
Hello, thanks for watching the video & glad you find it useful! I think, for the either-or case, it does not matter which equation you choose as f(x) or g(x).
@rubenstevenaar640
3 жыл бұрын
@@coverCell Thanks for the quick respond!
@flownamas31
3 жыл бұрын
Thank you very much for the video. I am wondering how do you write it down when asked either or both?
@coverCell
3 жыл бұрын
Hello. That's an interesting question. If I understand correctly, you are asking how to formulate this condition: we have two constraints, we must satisfy any or both of them but we can't violate both. I'm thinking if it's possible to use two sets of if-then constraints: (1) if Constraint 1 is violated, then Constraint 2 must be satisfied; (2) if Constraint 2 is violated, then Constraint 1 must be satisfied. What do you think? Thanks!
@xondiego
2 жыл бұрын
Hi and thanks for the video. How do you get the value of the Big M for the second example, and when the condition is in the capacities how can I get a good value for the big M? Thanks a lot!
@coverCell
2 жыл бұрын
Hello! In 26:00, for example, since each x may have the maximum value equal 1, then I think it is enough to set the M = 3 (to handle the situation when x21 = 1, x31 = 1, and x41 = 1); larger than 3 is also OK.
@xondiego
2 жыл бұрын
@@coverCell Thanks a lot for your response, very well understood, God bless you!
@hansotjes3459
Жыл бұрын
Hi @dididedi, would you know how to to treat an if statement like this: if X_1 + 2(X_2 + X_3) = 4 , then X_4 = 1. The reverse does not have to hold per se.
@coverCell
Жыл бұрын
Hello! That's an interesting question. Would it work if you transform those equations to these? X1 + 2X2 + 2X3 - 3 > 0 (this is the f(x)) X4 - 1 >= 0 (this is the g(x)) Then you apply the if-then formula 19:40
@alaratizer8495
2 жыл бұрын
hi, would it be the same process if we had constraints such as if you invest in 3 or more projects from this portfolio, you need to invest in at least 2 project in another portfolio. Would we still try to leave the inequality to the zero?
@coverCell
2 жыл бұрын
Hello! I'm thinking to solve such problem with a set of constraints like below. Let me know if it makes sense. Let's say we have portfolio A and portfolio B. The variable "a" is the sum of investments that we choose from portfolio A, out of 5 possible investments. a = xA1 + xA2 + xA3 + xA4 + xA5 b = xB1 + xB2 + xB3 + xB4 + xB5 The variables y1 and y2 are 0 or 1. If "a" is 3 or greater, y1 must be 1. a >= 3y1 b >= 2y2 Finally, we say that if y1 equals 1 (which means we invest in 3 or more investments from portfolio A), then y2 must equal 1 too. y2 >= y1
@alinateh6688
Жыл бұрын
hello didideidi, do u provide assignment help for linear programming on this? hope to hear from you soon as to how to contact you as it is urgent.
@coverCell
Жыл бұрын
Hello! Unfortunately, by now I do not provide help for assignments. I hope the examples on Linear Programming may help you: kzitem.info/door/PL0ZLI5mvN8kCsgjrK-YrTC81KY00rQKCK kzitem.info/door/PL0ZLI5mvN8kA8a1e4Z8mKDLMm1ydLhKRs
@rosspaterson1426
3 жыл бұрын
I have to come up with constraints so that x_1>2 and x_2>3 can not be true at the same time. Do you have any idea on how to go about this
@coverCell
3 жыл бұрын
Hello there. Here's my idea, do you think it would work? (x_1) - 2
@rosspaterson1426
3 жыл бұрын
@@coverCell yea that could work. Thanks for the help.
@coverCell
3 жыл бұрын
@@rosspaterson1426 You're welcome!
@coverCell
3 жыл бұрын
@AmazingTube Hello! Thanks for the correction. I changed the signs to become
@kaganesengin552
3 жыл бұрын
Great explanation, thank you!
@coverCell
3 жыл бұрын
You're welcome! I'm glad it helps and thanks for watching.
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