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Binary Representation of Information
bit: 0
byte: 0110 11000 "word": 01011100 11101111
00010000 11110000
chapter8
Slide 8-2
Digital Information (Binary)
There are 10 different kinds of people in the world: those who know binary and those who don't. --Anon
Slide 8-3
Digital Information (Binary)
Von Neumann ArchitectureA. CPU; B. RAM; C. I/O; D. Bus
What Can Computers Do?1. I/O operations2. Storage ops. (RAM, disk, disc, ...)3. Arithmetic ops. (+, -, *, /, %, ^, ...) 4. Logic ops. (<, <=, ==, !=, >=, >, AND,
OR, ...)
==> Computers are technologically complex but conceptually simple
Slide 8-4
Digital Information (Binary)
Pictures of the Tinker Toy computer.
How the Tinker Toy computer works.
Slide 8-5
Digital Information Processing Performance Speeds
How Fast Are Computers?
Two measures of throughput
MIPS: 2 ^ 3 ==> 8FLOPS: 3.14159 ^ 2.718 =
22.45186162
Supercomputers: MFLOPS; GFLOPS; TFLOPS; PFLOPS.
The Prefixes of the S.I.
Slide 8-6
Digital Information Processing Performance Speeds
Q: If a supercomputer can execute 1 GFLOPS, one instruction requires how much time to execute?A: 1 nanosecond.
Q: If a supercomputer can execute 1 PFLOPS, one instruction requires how much time to execute?A: ???
Slide 8-7
Information Processing Speeds
People
MFLOPS: recite 1..1M; 2 sec/recitation; 2Msec = 33,333 min. == 23 days
GFLOPS: recite 1..1G; 3 sec/recitation; 3Gsec = 50M min. == 34K days = 100 yrs
TFLOPS: recite 1..1T; 6 sec/recitation; 6Tsec = 200K yrs
Slide 8-8
Neurobiology
1011 neurons, each connected to 104 others
Switching Speed: 10-3 sec.vs.computer: 10-10 sec.
Yet humans are able to make surprisingly complex decisions, surprisingly quickly.
(eg) 10-1 sec. for infant to visually recognize its mother
Slide 8-9
Neurobiology
the information-processing abilities of biological systems must follow from highly parallel processes distributed over many neurons
Artificial Neural Networks
Slide 8-10
Artificial Intelligence Research:
Basic Premise
Genus:Information Processing System(IPS)
/ \Species: Biological Computers
Systems
Both species governed by same principles
Slide 8-11
AI Research
Scientific Metaphors
The heart is a pump
The brain is a computer (IPS)
Metaphor “The heart has its reasons of which reason knows nothing.”
-- Blaise Pascal
Slide 8-12
Digeratus: Alan Turing
During WWII Turing worked at Bletchley Park, Britain's codebreaking centre, & was responsible for German naval cryptanalysis. He devised a number of techniques for breaking German ciphers, including the method of the bombe, an electromechanical machine that could find settings for the Enigma machine.
Slide 8-13
The Turing Test for Intelligence: "Computing machinery and intelligence." (1950)
The Turing test is a proposal for a test of a machine's capability to demonstrate intelligence:
A human judge engages in a natural language conversation with one human and one machine, each of which try to appear human; if the judge cannot reliably tell which is which, then the machine is said to pass the test.
Slide 8-15
Five Categories of Information
1. Rover photos of Mars. Category: ? 2. 100 Kdigits of PI. Category: ?3. Clerk's Prolog, Canterbury Tales.
Category: ?4. Prelude & Fugue in C, J.S. Bach.
Category: ?5. A statement in a computer program.
Category: ?
Slide 8-16
Five Categories of Information
Q: Which of the 5 categories is this? 01011100 11101111 00010000 11110000
A: It could be any one of the 5(eg) How bit maps are used to represent images in
computers.
Slide 8-17
Why Do Computers Use Binary?
Nine Rungs of the Computer Inferno
1. Physics level.2. Device Level: Transistors3. Gate Level: AND, OR
PandA = TandF (p. 212)
“Logic is the foundation of reasoning, and the foundation of computing.
By associating true with presence & False with Absence, we can use the physical world to implement the logical world. This produces Information Technology.”
Slide 8-18
Why Do Computers Use Binary?
4. Machine Level:
full adder
a water adder
flip-flop (stores one bit)