Notes
Slide Show
Outline
1
Introduction to
Advanced AI Topics
  • Vision
  • Natural Language Processing
  • Robotics
2
Homework #2
  • We are not yet ready to hand out Homework #2.  We will probably have it ready for you by Friday.
  • You will be grouping yourselves into teams of three students via a web form.  We will announce the URL for this on Friday.


3
Advanced Topics Overview
  • Agents have sensors and actuators


  • Sensors:
    • Seeing (visual input) Ž Image Processing and Computer Vision
    • Hearing (audio input) Ž Natural Language Processing
  • Actuators:
    • Moving and manipulating Ž Robotics
4
Computer Vision
  • Perception
5
Definition: versus graphics
  • Graphics
    • Have world model W
    • Generate the sensory stimulus from the model
      S = f(W)


  • Vision
    • Generate the model from the sensors: W = f-1(S)
    • To think about: f() doesn’t have a proper inverse.  Why?
6
Ambiguity in sensory input
  • Girls playing with dollhouses
  • Or giants playing with people?
7
Definition: versus image processing
  • Image Processing
    • A transformation of data to other data
    • e.g., smoothing


  • Computer Vision
    • Reduction in data to a (more useful) abstraction
    • e.g., digit / face recognition
8
Applications
  • Surveillance – can we detect objects or people as they move around our field of vision?
  • Handwriting recognition – from handwritten addresses to barcodes
  • Content based Image Retrieval – query for images using without any text features.  “Show me similar pictures”
  • Automated Driving – speaks for itself
9
Natural Language Processing
  • Communication


10
Definition of NLP
  • Examines communication in human languages.
    • Theoretical and practical aspects.
    • Similar to vision, has production and understanding affects
      • Understanding: speech / text to meaning
      • Generation: meaning to speech / text
    • Both processes have inherent ambiguity
11
Not so great newspaper headlines
  • Squad helps dog bite victim.
  • Helicopter powered by human flies
  • Portable toilet bombed; police have nothing to go on.
  • British left waffles on Falkland Islands.
  • Teacher strikes idle kids.
12
Sample Applications
  • Restaurant Query converts English queries into SQL.
  • MS Dictation converts speech into text
  • Babelfish translates Web pages to different languages
  • Summarizing multiple news articles from the web
13
Robotics
  • Planning in the real world environment
14
Getting around
  • Effectors
    • Sensors on effectors? Is the output noisy?
    • Low-level: need to build higher-level abstractions


15
Problems
  • Localization – where am I?
    • Mobile robots but also robotic arms
  • Mapping – what does my environment look like?
  • Moving – how do I get from here to my goal? What type of plan do I have execute?
16
Applications of robotics
  • Robotic Flight – robotic helicopter, unmanned piloting
  • Path planning for exploration
  • Rock climbing, perhaps difficult even for some of us
17
Summary
  • All three areas deal with search:
    • Vision: search for most likely world w given input sensor s
    • Natural Language Processing: given an input utterance / text i, find most likely meaning m
    • Robotics:
      • Localization: given unknown input configuration / location, determine configuration.
      • Planning: given goal g and state s output plan p to reach g from s
18
Summary
  • All three areas use heuristics :
    • Vision: trihedral structure
    • Natural Language Processing: grammars of language, most frequent meanings
    • Robotics: decomposition of problems into cells, maximizing distance between obstacles
  • Many of these heuristics involve probability, which we will return to at the end of the semester.