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OCR Computer Science Paper 2 J276/02 - Thursday 16th May 2019 (Revision Material)

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Reply 140

sonu2003

For me paper 1 was way easier except for that tcp/ip question and hmaish's ****ing cipher **** Lol

Original post by HAMISH_CIPHER

I found it easier than paper 1 :/

Reply 141

sonu2003

1)(a) (i) What is meant by sampling? The sampling is used to store the audio recordings by using software to get frequent samples of sound from the audio file at certain intervals and converting them into binary to represent the audio.

(ii)What is meant by sampling frequency? Sampling frequency is the measure of the amount of samples/snippets of audio is taken and converted into a binary value.

(b)(i) How is binary used to represent Bitmap images? Bitmap images are represented with pixels, and each of the pixels represent different parts of the image and the colours of the pixels are represented by binary and different binary numbers for the image will determine the colour of the pixels and its colour depth.

b(iii) An image is being uploaded into a website and it has been compressed through the use of lossy compression What are the advantage and disadvantage of lossy compression? Advantage is that lossy compression will permanently delete some unrequired data or data thats not really needed from the image will, which will help reduce the size of the file. Disadvantage is that lossy compression will delete some data form the image file this will decrease the quality of the image file.

3) (d) (i) What is purpose of the Boolean variable swaps in this algorithm? The Boolean variable swaps is used to create an iteration within the bubble sort algorithm program which will make sure that it repeats till all of the data items had been put into the correct order.

Alright everyone, lets make an unofficial mark scheme, submit the answers to the questions u think is correct. Feel free to say anything if you disagree with any of the answers if u think they are invalid.

(edited 4 years ago)

Reply 142

IsMo987

For sampling frequency could I put the intervals that data were recorded

Reply 143

sonu2003

Yh you could put that, What did you put for the defensive design question?

Original post by IsMo987

For sampling frequency could I put the intervals that data were recorded

Reply 144

IsMo987

Original post by sonu2003

Yh you could put that, What did you put for the defensive design question?

Input sanitisation and input validation but I also added presence and range checks

Reply 145

sonu2003

Do u think I could say anticipating misuse through input validation and sanitation
and allowing users access to only certain parts of the system and disallowing access to certain parts of the program?

Original post by IsMo987

Input sanitisation and input validation but I also added presence and range checks

Reply 146

HAMISH_CIPHER

same here

Original post by IsMo987

Input sanitisation and input validation but I also added presence and range checks

Reply 147

HAMISH_CIPHER

Took me 10 mins to figure that shi* lol

Original post by sonu2003

For me paper 1 was way easier except for that tcp/ip question and hmaish's ****ing cipher **** Lol

Reply 148

lokidokie

I pretty much did this but decided to do 'while eightPeople = false' and set it to when the counter reaches 8 it'll make it true,,, smh I don't know what I was thinking lol

Did everything else though, so hopefully I won't lose too many marks.

Also, anyone have any code for what they did in the two 6 markers? Would be great. :smile: