Data representation Flashcards
what is a “set”
an disorganized collection of unique elements {finite or infinite}
symbol for “Real Numbers”
R
symbol for “Irrational numbers”
R-Q
symbol for “Rational numbers”
Q
symbol for “Integers”
Z
symbol for “Natural numbers”
N
what are “Ordinal numbers” and what do they describe
Natural numbers that describe the position of values in a set
what is “Enumeration”
letters being used in a set of ordinal numbers
what is a use of “natural numbers”
counting
what is a use of “ordinal numbers”
ordering
which includes all numbers
Real
which includes numbers that cant be expressed as a fraction
Irrational
which numbers include fractions (and integers)
Rational
“Integers” include natural numbers but the opposite isn’t true why
Natural numbers don’t include negatives, as they are an infinite set above zero
Nyquist’s theorem
sample rate must be at least double the highest frequency
What are 4 methods of error checking?
parity bits, majority voting, checksum and check digit (which is just data validation)
routers role in sending messages from private devices across a network
Routers do network address translation to switch the private IP with their own public IP
Fixed point (don’t recall just read)
assume unsigned
0.343752=0.688
0.6882=1…ans
0.ans2=0…ans
0.ans2=1…ans
1111.0101
Floating point
assume 2s compliment(signed)
effect of the exponent when positive and negative (floating point)
Like standard form but base 10 is replaced by base 2
Mantissa: is binary number (fixed point)
Exponent: multiplication value
normalisation
For memory efficiency,
Avoids lead 0s and 1s for positive and negative numbers respectfully.
Kilo vs Kibi
10 to 3 vs 2 to 10
What is Meta Data
Data About Data (i.e location) that increases file size
Effect of allocating more bits to the Mantissa
Greater precision of the number
Effect of allocating more bits to the Exponent
Greater range of numbers can be represented
Benefits vs Negatives of a Bitmap Image
++
1. each pixel can be manipulated
(greater detail)
2. fixed file size
–
1. loses quality when enlarged
2.Meta data stored on each pixel means file size can get very large
Vector Images Benefits
- Can be scaled without losing quality
- each object can be manipulated (instead of individual pixels)
3.Objects can be stacked (useful for map imaging) - Less storage space for simple shapes
Vector Images Negatives
- difficult to make complex/detailed shapes from instructions
- can take more storage when representing images with high color depth
Analogue to digital converter (ADC)
- Audio recorded and converted into current
- Sampled at regular Intervals for amplitude
- values are quantized into discrete values
- represented by binary values
Midi Sound
electronic instruments connected to computer give stored event messages to device on what audio to play
Midi Sound Benefits vs Negatives
++
1. Smaller size // no BG noise
2. easier to manipulate
–
1. Less realistic
2. Cannot Mimic Human vocals
