You are Here: Home

# COMP3 - JUN 2016 Discussion Thread

Announcements Posted on
Last day to win £100 of Amazon vouchers - don't miss out! Take our quick survey to enter 24-10-2016
1. (Original post by Polyrogue)
Could somebody quickly make a quick summary of subnet masks and Subnet IDs? I'm pretty sure I get it, but I want to be certain, thanks.
Subnet mask identifies which computers are on the same segment
Subnet mask does an AND operation with the student's computer IP address
Result of AND operation is the network ID
Network IDs compared
If the networks id dont match computers arent on same segment

network id/ subnet id i think theyre the same and this was worth 6 points
2. (Original post by QuantumSylar)
Subnet mask identifies which computers are on the same segment
Subnet mask does an AND operation with the student's computer IP address
Result of AND operation is the network ID
Network IDs compared
If the networks id dont match computers arent on same segment

network id/ subnet id i think theyre the same and this was worth 6 points
Just in time, and as suspected. Thanks a lot!
3. So how did everyone find it?

For the table of 3 notations i said the 2nd one is a flowchart what did you guys say it was
4. There was a question about the how to make the floating point more precise without losing the range. I since the pattern is always 1.0 or 0.1 we can represent the 2 patterns using one bit where a 1 = 0.1 and a 0= 1.0 this way you can free up a bit space in the mantissa without using any bits from the exponent. (3 or 4 marks)

The Question about picking a number to show what things are similar to the Turing machine I wrote 4,3.(2 marks)

The transition function question did everyone end up on state Sr with the following data in the tape at the end ###01. (6 marks)

For the question asking what it does i said it rearranges the data in the tape backwards. (1 mark)

for the delete algorithm i wrote:
current <== Start
While Current.Datavalue not equal to DelItem
do
Previous <== current
Current <== Current.Next
End of While
Previous.Next <== Current.Next
Release (Current)
(8 marks)

for the regex question I got (a ((ba)*c*a)|bb|bc)) |b|c) (a|b|c)* (1 mark)
5. (Original post by aelahi23)
for the regex question I got (a ((ba)*c*a)|bb|bc)) |b|c) (a|b|c)*
You only have to talk about that will end up in the accepting state, I said a(ba)*c*
6. (Original post by MathsAndChess)
You only have to talk about that will end up in the accepting state, I said a(ba)*c*
Did it? I must of misread the question then
7. So, just finished the paper. Think I did well enough. Answers are roughly as follows, (that I can remember)

Accounting, Authentication
Worms and Viruses both replicated, viruses attach themselves to files while worms spread through networks.
Digital signatures. Calculate a mathematical representation of the message using a hashing algorithm.

Serial transmission is cheaper and does not require a clock to be in both devices

Largest negative number was 1000001 01111 (though I accidentally made the exponent 11111)
Number was -1344
12 and 3/4 was 1100.11 in standard binary so therefore 0110011 00100 in floating point
Increase precision by removing leading 0s or 1s

Turing machine reversed the input 10 became 01

For the question about psuedo-code, I imagine a lot of people will lose marks if they forgot to set the value of the start pointer if DelItem was the first item in the list.
Code:
```Procedure DeleteItem(DelItem: String)
Release(Current) //Incase it was already in use, release allows it to be reused
If (Start.DataValue = DelItem)
Current = Start.Next
Release(Start)
Start = Current
Release(Current)
Else
Do
Release(Previous)
Previous = Current
Release(Current)
Current = Previous.Next
Until (Current.DataValue = DelItem)
Release(Previous.Next)
Previous.Next = Current.Next
Release(Current)
EndIf
EndProcedure```
I used all the Release's as it suggested they needed to be released to be reused later on and therefore my code would need to do the same.

SQL was
SELECT SpecifiedSpeed, DateSent, Price, (something else) FROM Parcel, PriceBand WHERE Parcel.Weight <= PriceBand.MaxWeight AND Parcel.Weight >= PriceBand.MinWeight AND PriceBand.SpecifiedSpeed = Parcel.SpecifiedSpeed AND Parcel.CustomerID = 109 ORDERBY DateSend DESC

Diagram was a Syntax Diagram
Different diagram was 3 (regex) because it required there to be a + or - preceeding the binary string, while the other two would also accept no sign.
Regex a(ba)*c*
8. the regex question was a(ba | c)*
9. i got (a | (b|c) ) *
for the delete algorithm i wrote:

start = 0;
repeat
increment start
Previour.datavalue = current.next
until current.datavalue = DelItem
Release[Current.DataValue]

did anyone get -1344 or -1334 for the mantissa question.
10. (Original post by KnightCode)
i got (a | (b|c) ) *
for the delete algorithm i wrote:

start = 0;
repeat
increment start
Previour.datavalue = current.next
until current.datavalue = DelItem
Release[Current.DataValue]

did anyone get -1344 or -1334 for the mantissa question.
Start, Current and Previous were pointers, therefore none should have been integers.

Some of my answers are above, you can compare.
11. (Original post by Sharpify)
Largest negative number was 1000001 11111
Shouldn't the Mantissa be positive?
12. (Original post by compFed)
the regex question was a(ba | c)*
Yeah, I just realized this.
13. (Original post by MathsAndChess)
Shouldn't the Mantissa be positive?
Whoops.
14. I don't remember the question asking to write the largest negative number in denary
In floating point representation i wrote
Mantissa=1.000000
Exponent= 01111

Can someone confrim wether you had to write it in denrary form.

I got 84 or -84 for converting the given floating point to the denary
15. why is SaaS different from a conventional thin client - I said because terminals are not dumb terminals
16. (Original post by Sid1234)
why is SaaS different from a conventional thin client - I said because terminals are not dumb terminals
I said SaaS tends to be web servers which are provided by company, there is a reliance on the internet and the company that provides theses SaaS e.g.
17. (Original post by Sid1234)
why is SaaS different from a conventional thin client - I said because terminals are not dumb terminals
The software is not stored on the same network as the client.
18. Also, what do we reckon for the A* this year?
19. Regex was a(c|ba)*
Largest neg number is 1000000 01111
The second diagram is called a syntax diagram
The transition function you end up in state S(h) (obviously if you ended in S(r) you should've realised you're wrong) with 01

For the SQL was price included in parcel or not? I thought it wasn't, so my SQL was:
SELECT Postcode, OrderDate, Price, OneOtherThing
FROM Parcel, ParcelPriceBand (whatever it was called)
WHERE CustomerID = 109
AND Weight => Minweight
AND Weight <= Maxweight
AND Parcel.Speed = ParclePriceBand.Speed
ORDER BY OrderDate ASC
20. unofficial markscheme?

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: June 23, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

### How does exam reform affect you?

From GCSE to A level, it's all changing

Poll
Useful resources