NO WORDS can match up to the simplest n easiest language this professor uses... sir, u r truly amazing... i was so worried about ma final sem oral of OR, ur lectr were of gr8 help... fundamentals r so cleared now.... thank u...
I think that at 10:54 instead of "dual infeasibility implies primal's optimality" one should say, "dual feasibility implies primal's optimality" as it was explained in one of the earlier lectures in the playlist considering the primal-dual relationships in the Simplex Algorithm. Thanks to Prof. G. Srinivasan for these wonderful series!
The relationship between the (i)(price of selling) = (price of purchase) + (price of transportation) is easy to understand with this explanation. However I couldn't immediately grasp why is it represented in the numbers of the given example in the way it was represented there. I think that the following note is helpful (and I think it's correct), that u_i, being the "out cashflow", i.e. the money that the third person pays, is intrinsically taken with the negative sign when we are adding the positive values of u_i and v_j. Then, if we rewrite the equation I denoted as (i) considering those signs (and assuming, as it is assumed in the problem that both u's and v's are positive values), we'll get: v_j = - u_i + c_ij => u_i + v_j = c_ij which is precisely one of the equations actually working in the method. Once again, thanks to guru ji G. Srinivasan for a wonderful explanation, which I hope I could make even more clear with that little remark.
I have same confusion about this part. Your explanation of adding a negative sign to u_i makes sense in terms of dual feasibility. However, under this assumption, if you increase u_i, then v_j would go down because c_ij is fixed, which mainly says if the third party person get the commodity with a higher price, then he would like to sell the commodity for less, which doesn't make sense. So, I'm not sure if adding a negative sign to u_i really works.
You look at the primal problem, two types of constraints are there. One Is < or = and second is > or =, since the primal problem has a minimization objective therefore we will have to change all the constraints into greater than equal type(> or =) that is the standard form we convert it into dual. Converting less than equal to type constraints into greater than equal to type constraints will give us a negative sign in every constraints which have less than equal to type sign. Precisely these are those constraints which are associated with u_i's. So it finally results in v_i - u_i = C_ij Since the teacher has not converted it. and he Considered the original problem therefore it takes. v_i + u_i = C_ij
Thank You Sir. I felt OR subject interesting after listening to your lecturues. I have studied almost all your lectures. Hope for your support in future too. Thank You Sir
Hello, I'm confused by the economic interpretation of the dual variables. @16:38, it is said that c12=6=v2-u1=6-0. If we interpret this way, then how about c23=6? v3-u2=5-1 which is not equal to c23.
thnk u so much sirrrr...i was so confused bout all dis stuff......saw dis videos a day bfore my practicals ...still helped a lot ..............thnk u soooo much .......
Excellent explanation, if any one interested then please join NPTEL online certificate examination for the course Introduction to Operations Research by Prof. G. Shrinivasan, IIT - Madras.
Assignment Problem starts at 47:35
Thanks for all these wonderful lectures
Thanks mate!
unbalanced problems starts @23:30
Thank you
NO WORDS can match up to the simplest n easiest language this professor uses... sir, u r truly amazing... i was so worried about ma final sem oral of OR, ur lectr were of gr8 help... fundamentals r so cleared now.... thank u...
@1.00.00 there is a mistake, the column 2 sould be 2 1 0 3 be careful ,but still he is amazing
I think that at 10:54 instead of
"dual infeasibility implies primal's optimality"
one should say,
"dual feasibility implies primal's optimality"
as it was explained in one of the earlier lectures in the playlist considering the primal-dual relationships in the Simplex Algorithm.
Thanks to Prof. G. Srinivasan for these wonderful series!
True :)
18:44 preferred methods
23:33 unbalanced problems
30:02 some other aspects
The relationship between the
(i)(price of selling) = (price of purchase) + (price of transportation)
is easy to understand with this explanation.
However I couldn't immediately grasp why is it represented in the numbers of the given example in the way it was represented there.
I think that the following note is helpful (and I think it's correct), that
u_i, being the "out cashflow", i.e. the money that the third person pays, is intrinsically taken with the negative sign when we are adding the positive values of
u_i and v_j.
Then, if we rewrite the equation I denoted as (i) considering those signs (and assuming, as it is assumed in the problem that both u's and v's are positive values), we'll get:
v_j = - u_i + c_ij
=> u_i + v_j = c_ij
which is precisely one of the equations actually working in the method.
Once again, thanks to guru ji G. Srinivasan for a wonderful explanation, which I hope I could make even more clear with that little remark.
I have same confusion about this part. Your explanation of adding a negative sign to u_i makes sense in terms of dual feasibility. However, under this assumption, if you increase u_i, then v_j would go down because c_ij is fixed, which mainly says if the third party person get the commodity with a higher price, then he would like to sell the commodity for less, which doesn't make sense. So, I'm not sure if adding a negative sign to u_i really works.
What about the transportation cost. Is it not the cash outflow? It should also be represented by a negative sign then.
I think there is something missing in this interpretation of variables of transportation problem
You look at the primal problem, two types of constraints are there. One Is < or = and second is > or =, since the primal problem has a minimization objective therefore we will have to change all the constraints into greater than equal type(> or =) that is the standard form we convert it into dual.
Converting less than equal to type constraints into greater than equal to type constraints will give us a negative sign in every constraints which have less than equal to type sign.
Precisely these are those constraints which are associated with u_i's. So it finally results in v_i - u_i = C_ij
Since the teacher has not converted it. and he Considered the original problem therefore it takes. v_i + u_i = C_ij
Thank You Sir. I felt OR subject interesting after listening to your lecturues. I have studied almost all your lectures. Hope for your support in future too. Thank You Sir
Hello, I'm confused by the economic interpretation of the dual variables. @16:38, it is said that c12=6=v2-u1=6-0. If we interpret this way, then how about c23=6? v3-u2=5-1 which is not equal to c23.
I am getting confused at 59:40 please some clarify. Thanx
Why I never find such useful videos when I need them?
It is really an amazing lecture. Thank you very much.
This teacher is awesome he is the best for sure
thnk u so much sirrrr...i was so confused bout all dis stuff......saw dis videos a day bfore my practicals ...still helped a lot ..............thnk u soooo much .......
column subtraction for assg problem will be 0,1,0,3 and not 0.1.0.6
sir, U have truly great have explained us in a very nice and simple way. Truly superb.
Excellent explanation, if any one interested then please join NPTEL online certificate examination for the course Introduction to Operations Research by Prof. G. Shrinivasan, IIT - Madras.
59:49 doubt
you are simply amazing sir.. thank u so much!!!!!
@anandkasirajan
watch the lec-14 for stepping stone method.
Very nice lecture 👌👏
Thanks
Thanks a lot sir for such a wwonderfull lecture .
thank you so much sir , i really appreciate sir !
thanks for these lectures!!!!!!!!!
lecturer 15 and 16 superb good
column subtraction at column 2 is wrongly done but still a very good tutorial
thanx sir.............
thanks.
thank you sir
Unbalanced TP @ 23:41
At 59:40 professor messed up..😡
Prashant Jha he's human too
sir, you are a legend.
thank you sir