Chapter 4 (Pt. 1)

Question 1

What are the fundamental building blocks of all computer systems?

Answer 1

• Binary Represenation
• Boolean Logic
• Gates
• Circuits

Question 2

How are numeric and textual information represented?

Answer 2

Two types of information representation

• External Represenation
• Internal Represenation

Binary represenation is a base-2 positional numbering system.

Question 3

How do we convert from binary-to-decimal?

Answer 3

• Whenever there is a 1 in a column, add the positional value of that column to a running sum
• Whenever there is a 0 in a column, add nothing
• The final sum is the decimal value of this binary number.

Question 4

What are the preset limiations to binary storage?

Answer 4

Maximum number of binary digits that can be used to store integers: 16, 32, or 64 bits.

Question 5

Define:

Arithmetic Overflow

Answer 5

Operation that produces an unasigned value greater than 65,535; 16 bit system.

Question 6

What is the alternative name to the base 8 system?

Answer 6

Octal Numbering Sytem

Question 7

How do you convert from binary to base eight (vice versa)? from base ten to eight (vice versa)?

Answer 7

To covert from binary to base eight: group in threes.

To convert from eight to binary: expand in threes.

From ten to eight: use binary as the intermediate.

Question 8

What is the alternative name for base sixteen?

Answer 8

Hexadecimal Numbering System

Question 9

How do you convert from binary to base sixteen (vice versa)? from ten to base sixteen (vice verse?

Answer 9

To convert from binary to base sixteen: group in fours.

To convert from base sixteen to binary: expand in fours.

To convert from base ten to sixteen use binary as an intermediate.

Question 10

How are fractional numbers represented in binary?

Answer 10

Can be represented in binary by using signed integer techniques; assigned a specific bit(s) as indicators for decimal or cutoff.

Normalize the number

• First significant digit is immediately to the right of the binary point

Question 11

How is scientific notation represented in binary?

Answer 11

• ±M x B^±E
• M is the mantissa, B is the exponent base (usually 2), and E is the exponent

Question 12

How is textual information encoded in binary?

Answer 12

Code mapping

• Assigning each printable letter or symbol in our alphabet a unique number

ASCII

• International standard for representing textual information in the majority of computers
• Uses 8 bits to represent each character.

Question 13

Describe encoding systems.

Answer 13

• Encoding systems are used to assign a number for each letter or character
• There are many possible encoding systems, with each one using its own assignment

Question 14

What are certain pitfalls of different enconding systems?

Answer 14

• Any given computer needs to support different encodings
• When data is passed between different encodings or platforms, the data runs th risk of corruption.

Question 15

Define:

Unicode

Answer 15

• An international encoding standard for use with different languages and scripts.
• Each letter, digit, or symbol is assigned a unique numeric value that applies across different platforms, program and languages.

Question 16

Why is unicode so beneficial?

Answer 16

• Unicode standard has been adopted by industry leaders
• Unicode enables a single software product or website to be targeted across multiple platforms, languages and countries without re-engineering.
• The Unicode consortium was founded to develop, extend and promote the use of the Unicode Standard.

Question 17

What are the different types of encoding?

Answer 17

UTF - 8

• Variable byte representation
  
  • 1 byte to 4 bytes per code point
• First 128 characters are encoded just like ASCII

UTF - 16

• Variable byte representation
• 2 bytes to 4 bytes per code point
• Optimized for languages residing in the 2 bytes character range

UTF - 32

• Fixed width byte representation
• 4 bytes per code point

Question 18

How are characters assigned numbers in unicode?

Answer 18

Characters are assigned a number written in the U+XXX form.

• Called a Code Point
• Example: U+0041
• The numbers are hexadecimal
  
  • Listed on the Unicode website
• Hellow is represented by a list of points
  
  • U+0048 | U+0065 | U+006C | U+006F

Question 19

What are the differences in enconding between different versions of python?

Answer 19

Python 2

• Enconding is ASCII
• Not all python 2 internal supports Unicode

Python 3

• ”< type ‘str’ >” is a Unicode Object
• All built-in modules support Unicode
• Default enconding is UTF-8, not ASCII

Question 20

Define:

Digital Representation

Answer 20

Values for a given object are drown from a finite set.

Question 21

Define:

Analog Representation

Answer 21

Object can take on any value

Question 22

What does amplitude measure?

Answer 22

It measures loudness

• Units: Electrical Voltage

Question 23

What does period measures?

Answer 23

Time it takes for the wave to make on complete cycle

• Units: Time (Seconds)

Question 24

What does frequency measure?

Answer 24

Total number of cycles per unit time

• Units: Hertz (Hz)

Question 25

# Define: Sampling Rate

Answer 25

Measures how many times per second we sample the amplitude of the sound wave.

Question 26

# Define: Bit Depth

Answer 26

Also known as Sampling Precision; the number of bits used to encode each sample.

Question 27

# Define: MP3

Answer 27

Most popular and widely used digital audio format * wave files also exist but less popular.

Question 28

# Define: Scanning

Answer 28

Measuring the intesity values of distinct points located at regular intervals across the image's surface.

Question 29

How qualitative are CD recordings?

Answer 29

* Sampling rate: 44,000 times per second * Lower sampling rate produces distortions detectable to the human ear.

Question 30

What role do bit-systems play in bit depth or sampling precision?

Answer 30

* 1 byte (8 bits) can represent 256 levels (2⁸ levels) * 2 byte (16 bits) can represent 65,536 (2¹⁶ levels)

Question 31

How is the resolution of an image determined?

Answer 31

The density of pixels used to represent the image

Question 32

If you were to superimpose a grid on an image, how would you store the information of the image?

Answer 32

* Only store one color of information for each square of the grid. * For a given image, more squares increases the resolution.

Question 33

Which are the common units of resolution?

Answer 33

* Dots per inch (example: 72 dpi) * Pixels: (example: 640 x 480 pixels)

Question 34

# Define: Raster Graphics

Answer 34

* Each pixel is encoded as an unsigned binary value representing its gray scale intensity * Individual pixels can be edited * Number of bits used for each pixel affects image quality and amount of memory needed to store the image.

Question 35

# Define: RGB Encoding Scheme

Answer 35

Most common format for storing color images Specify the red component, the green component and the blue component separately. True Color * 24-bit color-encoding scheme * 8 bits per color (Red, Green, Blue)