Exploring Digital Information Technologies: Lecture 1- Part 2
Exploring Digital Information Technologies: Lecture 1- Part 2
The Landscape—Information and Computation
Encoding Digital Information
Encoding Digital Information
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Digital information is data encoded into symbols.
Most common form of digital data is the Binary Digit or Bit (it stores a teeny bit of information).
Most common form of digital data is the Binary Digit or Bit (it stores a teeny bit of information).
A bit can either be 0 or 1.
How is information coded?
How is information coded?
Question: What is your favorite color?
Answers:
Encoding color information using numbers
Encoding color information using numbers
The answers are information about us.
Here are a few colors:
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We can use a number to represent each color.
There are 9 colors, so the numbers 0-8 can be used:
There are 9 colors, so the numbers 0-8 can be used:
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0,1,2,3,4,5,6,7,8
Encoding with bits
Encoding with bits
However with bits you have only 0 and 1 to encode all the information. Why just 0 and 1?
Information is Stored Physically
Information is Stored Physically
How do we store information?
How do we store information?
In a digital system, information is stored using physical quantities such as:
◼
voltage,
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crystal structure, or
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magnetic field.
Storing Information Physically
Storing Information Physically
Physical storage systems typically have two states: off or on OR which we can call 0 and 1.
That gives us a binary digit, or bit.
How do we measure information?
How do we measure information?
Information is measured by how many bits are needed to store it.
How is information coded into bits?
How is information coded into bits?
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0,1,2,3,4,5,6,7,8
How many bits would we need to store 9 different numbers? Let’s start small
1 Bit
1 Bit
2 Bits
2 Bits
With 2 bits we can store 4 numbers (or colors or names or 4 of anything):
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Numbers
Numbers
Colors
Colors
Mickey and Friends
Mickey and Friends
3 Bits and 4 Bits
3 Bits and 4 Bits
From Bits to Decimal Numbers and Back
From Bits to Decimal Numbers and Back
You don't have to do the math but you must understand how it works.
How many different things can we represent with “n” bits?
How many different things can we represent with “n” bits?
How many bits do we need to represent “n” different things?
How many bits do we need to represent “n” different things?
Encoding Images
Encoding Images
What to do with lots of bits?
What to do with lots of bits?
Compression
Compression
What is Computation?
What is Computation?
Travel Directions
Travel Directions
Identifying Images
Identifying Images
Social Network Analysis
Social Network Analysis
Church-Turing Hypothesis
Church-Turing Hypothesis
Terminology You Should Know from this Lecture
Terminology You Should Know from this Lecture
Concepts You Should Know from this Lecture
Concepts You Should Know from this Lecture