[D556mm]

Hey guys, making this thread because of the upcoming Decision 2 exam this week. Our class has finished the syllabus late and I was wondering if anyone had any revision notes, especially Network flows.

Thanks guys and to all of you taking it, good luck

[walkbesideme]

Hi, I haven't got any notes as such but I can answer any questions if you have them =)

[stupefy!]

(Original post by D556mm)
Hey guys, making this thread because of the upcoming Decision 2 exam this week. Our class has finished the syllabus late and I was wondering if anyone had any revision notes, especially Network flows.

Thanks guys and to all of you taking it, good luck

I have also just finished the syllabus late as I have self taught it. I don't have any revision notes but, like the other poster said, I will be happy to answer any questions you have!

Good luck to you too!

[Dangerous Theory]

Exam should be fine as long as they don't decide to ask some unorthodox question that we haven't recognized from past papers. I think flow augmentation is the most thought-requiring part - I find it easy to get confused on that. Also simplex is a mistake magnet especially when you're adding /subtracting multiples of fractions. It doesn't help that the module is so unbelievably boring! Dijkstras and maximum matching were kinda fun in D1.. The best we've got now is. Hungarian algorithm >. < lol

This was posted from The Student Room's Android App on my GT-I9300

[walkbesideme]

(Original post by Dangerous Theory)
Exam should be fine as long as they don't decide to ask some unorthodox question that we haven't recognized from past papers. I think flow augmentation is the most thought-requiring part - I find it easy to get confused on that. Also simplex is a mistake magnet especially when you're adding /subtracting multiples of fractions. It doesn't help that the module is so unbelievably boring! Dijkstras and maximum matching were kinda fun in D1.. The best we've got now is. Hungarian algorithm >. < lol

This was posted from The Student Room's Android App on my GT-I9300

I dunno - I quite enjoy doing game theory

My personal hatred lies exclusivly for resource levelling but it was on in january so hopefully they don't ask about it

[Jarred]

I'm doing this as a resit. Haven't studied it since January 2011, but I managed to reteach the whole module to myself in a day, it's quite empty when you think about it. My only issues are network flows and resource leveling.

I have a question though, is it possible for there to be multiple correct solutions to the questions for network flows? Maybe to have a diagram which looks slightly different but has the same max flow, just maybe with one or two edges having different weights? I got this once and thought maybe the order you choose your augmenting paths affects the flow on certain edges, but still gives a correct answer? Is that so? Or did I go wrong?

[Dangerous Theory]

(Original post by Jarred)
I'm doing this as a resit. Haven't studied it since January 2011, but I managed to reteach the whole module to myself in a day, it's quite empty when you think about it. My only issues are network flows and resource leveling.

I have a question though, is it possible for there to be multiple correct solutions to the questions for network flows? Maybe to have a diagram which looks slightly different but has the same max flow, just maybe with one or two edges having different weights? I got this once and thought maybe the order you choose your augmenting paths affects the flow on certain edges, but still gives a correct answer? Is that so? Or did I go wrong?

It's possible. I believe the mark scheme often has a comment such as "several possibilities".

I agree resource levelling is horribly but thankfully uncommon and i hope it doesn't appear. In terms of easy marks game theory and Hungarian are the best imo.

My problem is the book is a massive POS. Very hard to follow and mainly based on OCR questions which indicates it probably isn't much involved with AQA. I dont understand why there isn't a book by the same author as D1. Then again, the subject is utterly useless anyway and a wasteful maths module. I just need to average an A on this and M2 to get an A for further maths!

[f1mad]

(Original post by Dangerous Theory)
It's possible. I believe the mark scheme often has a comment such as "several possibilities".

I agree resource levelling is horribly but thankfully uncommon and i hope it doesn't appear. In terms of easy marks game theory and Hungarian are the best imo.

My problem is the book is a massive POS. Very hard to follow and mainly based on OCR questions which indicates it probably isn't much involved with AQA. I dont understand why there isn't a book by the same author as D1. Then again, the subject is utterly useless anyway and a wasteful maths module. I just need to average an A on this and M2 to get an A for further maths!

I thought the book was fine. Was **** for the topic on network flows though.

[Dangerous Theory]

(Original post by f1mad)
I thought the book was fine. Was **** for the topic on network flows though.

Compared to the heinemann books, it's terrible.

This was posted from The Student Room's Android App on my GT-I9300

[f1mad]

(Original post by Dangerous Theory)
.. In terms of easy marks game theory and Hungarian are the best imo.

Simplex too.

[stupefy!]

Does anyone have a link to January 12?

[magdaplaysbass]

I'm doing this exam too. Last time I did it was in Jan 2011; but D2 is one of the exams that you can learn quite quickly. I'm not a fan of resource levelling and creating Dynamic Programming networks; but the rest is alright

[Jarred]

(Original post by Dangerous Theory)
It's possible. I believe the mark scheme often has a comment such as "several possibilities".

I agree resource levelling is horribly but thankfully uncommon and i hope it doesn't appear. In terms of easy marks game theory and Hungarian are the best imo.

My problem is the book is a massive POS. Very hard to follow and mainly based on OCR questions which indicates it probably isn't much involved with AQA. I dont understand why there isn't a book by the same author as D1. Then again, the subject is utterly useless anyway and a wasteful maths module. I just need to average an A on this and M2 to get an A for further maths!

Ok that's good to know, cheers.

Do you have the Stan Dolan book? I don't like it either. And yeah, I also hate D2. I'm only resitting it to see if I can get an A* overall, and it's the easiest A2 module I have. Wish my school taught something like M2 instead though.

[Dangerous Theory]

(Original post by Jarred)
Ok that's good to know, cheers.

Do you have the Stan Dolan book? I don't like it either. And yeah, I also hate D2. I'm only resitting it to see if I can get an A* overall, and it's the easiest A2 module I have. Wish my school taught something like M2 instead though.

Yeah Stan Dolan. I don't believe there is an alternative? Are you doing further Maths? Cause they're both part of my FM grade


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[magdaplaysbass]

Can anyone please tell me why 12 & 19 haven't been included in the value of the cut? Thanks

[D556mm]

(Original post by magdaplaysbass)
Can anyone please tell me why 12 & 19 haven't been included in the value of the cut? Thanks

Because the part underneath the cut is the Source region and above is the Sink region. If you look at the directions of the arrows, only 38, 25 and 34 move from the source region to the sink region where as 19 and 12 are moving from Sink region to Source region

[magdaplaysbass]

(Original post by D556mm)
Because the part underneath the cut is the Source region and above is the Sink region. If you look at the directions of the arrows, only 38, 25 and 34 move from the source region to the sink region where as 19 and 12 are moving from Sink region to Source region

ah, i never thought about it that way. thank you!!

[originalsteph]

hey could some one help me on question 6 iv ) Indicate on Figure 5 a possible flow along each edge corresponding to this
maximum flow

I found out that the maximum flow is 53 but i don't understand what to do for this question


AQA-MD02-W-QP-JAN10.PDF

[Jarred]

(Original post by Dangerous Theory)
Yeah Stan Dolan. I don't believe there is an alternative? Are you doing further Maths? Cause they're both part of my FM grade


This was posted from The Student Room's iPhone/iPad App

Yeah, apparently some of the other spec's books are OK for some parts of our spec but then obviously you're not going to get all of it so unfortunately the Dolan book is the only one for D2 on AQA. His book isn't too bad, I've read worse textbooks, but then it's not amazing either.

Yeah I am but we do FP4 instead of M2. Only mechanics module I ever sat was M1 as part of normal maths. Next year though at my school they're going to do M2 instead of FP4 because of how horrible the JAN12 paper was. I'd prefer they just got rid of D1 and D2 completely though.

[Jarred]

I've just thought of another couple of queries, anyone know the answers?

>Are you allowed to use pencil for the network flow questions? The papers say pencil should "only be used for drawing" Do network flows count as drawing?

>And if not; what if you go wrong on the figure/ diagram given (for any question, not just flows)? Can we request a replacement figure diagram to use, or do we have to draw it out by hand in the lined paper sections.