Artificial Intelligence in the World. Prof. Levy Fromm Institute Spring Session, 2017

Transcription

1 Artificial Intelligence in the World Prof. Levy Fromm Institute Spring Session, 2017

2 Lecture 2 agenda What is software and how is it made? History of computing Key people John von Neumann, John McCarthy Influence of the AI Lab at Stanford Components of modern AI systems Self-driving cars who, where, when

3 RASPBERRY PI 3 MODEL B BUY FROM OUR DISTRIBUTORS $30 The Raspberry Pi 3 is the third generation Raspberry Pi. It replaced the Raspberry Pi 2 Model B in February Compared to the Raspberry Pi 2 it has: A 1.2GHz 64-bit quad-core ARMv8 CPU n Wireless LAN Bluetooth 4.1 Bluetooth Low Energy (BLE) Like the Pi 2, it also has: 1GB RAM 4 USB ports 40 GPIO pins Full HDMI port Ethernet port Combined 3.5mm audio jack and composite video Camera interface (CSI) Display interface (DSI) Micro SD card slot (now push-pull rather than push-push)

4 History - Review Ada Lovelace (explained Babbage s unrealized Analytical Engine ) General-purpose (sequences of operations, storage, the mill) Symbols can represent anything, not just math Algorithm (with subroutines, loops, library of common routines, conditional branching) Code Alan Turing Any computation can be expressed in terms of a Turing Machine Proof that some things cannot be computed ( The halting problem ) (1936, at age 24, to Princeton with Einstein, Godel, von Neumann) Can machines think? (Ada s objection; Turing s test)

5 Computer fundamentals Instructions and Memory (RAM) data address program counter counter instruction counter +1 Central Processing Unit (CPU) registers ALU The mill (ALU) the mill Data Data or instruction

6 Instructions in Memory (Machine Code) Memory (RAM) Binary value Instruction (assembly code) Meaning data LDI R0,=6 Take the value 6 that is stored in this instruction and move it into Register 0

7 Machine code (in RAM memory)

8 Machine code

9 Instructions in Memory (Machine Code) Memory (RAM) Binary value Instruction (assembly code) Meaning data LDI R0,=6 Take the value 6 that is stored in this instruction and move it into Register 0

10 Object code or Assembly code

11 Object code or Assembly code

12 Object code or Assembly code

13 Software Source Code (what people write) Object Code (what s generated by a compiler) Library Code (what s saved from previous work) Machine Code (what actually runs in the computer)

14 High-Level Languages (for Source Code) Fortran Cobol C C++ C# Pascal

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16 Source Code

17 Source Code

18 Source Code

19 Source Code

20 Source Code

21 Source Code

22 Source Code

23 Compilers Take Source Code as input Generate Assembly Language or Machine Language as output The Compiler parses formulas to generate sequences of operations The Compiler keeps track of names (symbols), to allow the programmer to use any kind of name for variables, subprograms, etc. Even though in the computer, each one has to be referenced as a number (address)

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25 Software development process (part 1) Write Source code (using a text editor), store it on disk Compile Source code into Object code, store it on disk Link Object code modules with Library code modules, creating Load modules stored on disk When ready to run the program, read Load modules from disk into RAM memory Execute the program

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27 Software development process (part 2) Watch what the executing program does Such as read data in, write data out If the program stops prematurely (or has some other error), Look for what went wrong (a bug) When you figure out what went wrong, edit the source code to correct the error Repeat (Edit, compile, link, load, run)

28 Software development process (part 3) Use special debugging tools Testing the program with many possible input errors Extra source code that prints out something ( I got this far ) Extra source code that checks values of variables Breakpoints places where execution of the program stops to let you look at what the values of variables (and registers) are Traps that stop the program when something is obviously wrong Coverage maps did all of the code get executed?

29 Software development process (part 4) Software Engineering Requirements Analysis Design Development (writing the code) Quality Assurance (testing the code) Deployment (letting other people use the code) Maintenance (feedback from users of the code updates to the code) Agile software development Requirements will change during the development process Break the development into small pieces that can be done in a few days Demonstrate the working pieces before continuing

30 History Alan Turing Turing Machine on computable numbers 1943 Colossus code-breaking The Turing Test: behavioral test only (ignore consciousness) Turing: learning? (anticipating current ANNs)

31 History From 1945 to Von Neumann stored program ENIAC, Univac Compiler Grace Hopper integrated circuit (Shockley; Noyce & Moore) 1959 MIT AI Lab John McCarthy 1961 PDP-1 donated to MIT (spacewar) 1962 Stanford AI Lab 1965 spacewar at SLAC

32 John von Neumann & the EDVAC computer

33 AI Labs - history John McCarthy MIT AI Lab (1959) à Stanford AI Lab (1962)

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35 I 1 PROaM.MWIED DATA PROCESSOR

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37 Self-driving Cars Who is developing them? Auto manufacturers: GM, Ford, BMW, Daimler, Tesla High-tech firms: Google, Apple, Uber Defense industry for industry (mining), military Universities & National labs (NASA)

38 AI Labs history & influence ShakeyIEEE milestone (29:44 35:00) video of Shakey impact on Mars rovers (3:28 total)

39 Modern AI systems Components Hardware Software Engineering disciplines Digital computers (CPUs, RAM, storage) Software Control systems Networks

40 Components of AI-based systems These are specific to AI Processors, software, modeling, abstraction Sensors (input devices) & Output devices Feedback control systems Communicating over networks (distributed computing) Including the internet and the World-Wide Web Pattern recognition Heuristics (rules of thumb for choosing responses or actions) Big Data

41 Self-driving Cars Sensor components Software components What drove the transition to practical self-driving cars? What culture? What events? The DARPA challenge (2005) Google - know the streets Uber in Pittsburgh