4.5 Fundamentals Of Data Representation Flashcards
1
Q
Hex vs Binary (2)
A
- code, read, spot errors
- 2 vs 8 digits
2
Q
Problems with Decimals (1)
A
Accuracy
3
Q
Absolute and Relative Errors (3)
A
Absolute = original - binary
Relative = absolute/original
Percentage = relative
4
Q
ASCII (4)
A
- English alphabet
- Simplify
- Some Symbols
- 7
5
Q
Representation (2)
A
- all have code associated
- global, uniform
6
Q
Unicode (3)
A
- ASCII + languages + £% + 😄
- ASCII used until Unicode needed
- less bits
7
Q
Parity Bit (2)
A
- simplest form
- even/odd - 1 bits
8
Q
Majority Voting (3) reliability
A
- fix interference
- 3 times
- more reliable but not 100%
9
Q
Parity vs Majority (6)
A
Storage = little. More
Multiple errors = ❎ ✅
Error fixing = ❎ ✅
Ease of creation = easy. Easier
Processing = less. More
Reliability = not very. Very
10
Q
Check Sums (3)
A
- bytes of data block added
- result transmitted with data
- accepted is checksum = result
11
Q
Check Digit (4) calculated?
A
- many algorithms
- calculated from code digits
- on end —> compared
- spot human error
12
Q
Bitmapped Graphics (3)
A
- resolution = width x height
- metadata: height, width, colour depth, file type
- photos, videos
13
Q
Vector Images (3) (5)
A
- objects layered + properties
- logos
- real life
- quality
- file size
- edit
- scalable
14
Q
Sound (2)
A
- sample rate = num samples per sec
- sample resolution = num bits available each sample
15
Q
Nyquist Theorem (1)
A
- sampling resolution = 2 x highest frequency
16
Q
MIDI (8) purpose, benefits etc
A
- technical standard
- protocol, digital interface, standard set of controllers
- allow communication between computers and instruments to synthesise sound
- controller —> event messages
- pitch, vibrato, note length, easily changed
- list of instructions
- easy to modify
- score generated directly from file
17
Q
Compression (4) comparison
A
- text files/programs
- transfer speed
- reduction
- original data can(not) be retrieved
18
Q
Run Length Encoding (3) examples
A
- redundant repeating data
- pixel by pixel, 1 instance + times repeated
- images, sound
19
Q
Dictionary Encoding (2)
A
- long passages, repeated words
- word by word, dictionary, unique reference, replaced
20
Q
Caesar Cipher (2)
A
- shift right n places
- simple, easy to crack
21
Q
Vernam Cipher (4) (4) comparison
A
- XOR gate (same = 1, diff = 0)
- same length, random, once, secure
- mathematically impossible
- code, generate, range of keys, secure
