Resolution Examples
Steps in Resolution Theorem Proving
translate English sentences (premises and query) into First-Order Logic sentences
we want to prove that the sentence (P1 P2 . Pn) Q is True
equivalently, we want to prove that the negation is inconsi
Chapter 2
Application Layer
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Chapter 2
Application Layer
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Articial Intelligence
W4701
Administration
texts required reading for each class from
Articial Intelligence: A Modern Approach, by Russell
& Norvig
The Minds I, by Hofstadter & Dennett
three assignments, 15 points each
four quizzes, 10 points each
one nal
Program = Data
Introduction to LISP
Linked Lists
in memory
BANANA
displayed as strings
MENU
FOX
357
(BANANA (FOX 357) NIL MENU)
improper lists
(A B . C)
A
BC
LISP and the REPL
LISP, invented by John McCarthy in 1959, was one
of the rst two 3GLs
programs a
Prelude. Ant Fugue
Intelligent Processing
What is the input? Sensory perceptions.
Sight: Images (still or moving)
Sound: Wave forms
Touch, taste, and smell: (uh. skip these, why?)
Perception: Translate images and sound waves into symbolic knowledge
repres
Uninformed Search
Traveling through Romania
currently in Arad
ight leaves tomorrow from
Bucharest
goal: be in Bucharest
problem:
states = various cities
actions = drive between
cities
solve:
nd the sequence of
cities to drive through:
Arad, Sibiu,
Heuristic Search
Best-First Search
use an evaluation function f(n) for each node
estimates desirability
expand most desirable node in fringe
enqueueing function maintains fringe in order of
f(n) smallest (lowest cost) rst
two approaches: Greedy and A*
Rom
Local Search
Local Search: Goal = Solution
integrated circuit design: how should the circuitry be laid
out on the chip to optimize space and function?
job-shop scheduling: how should resources (human or
equipment) be allocated and scheduled optimally?
Adversarial Search
Adversarial Search
optimal decisions with the Minimax algorithm
pruning
imperfect decisions
Adversarial vs Search
unpredictable opponent
explore moves for all possible replies
assume worst case (perfect opponent)
time limits force su
Knowledge Search
and
Propositional Logic
AI as Two Searches
so far, we have studied state space search
in state space search, the space is populated by states representing
congurations
you search through these congurations looking for a goal state the
First-Order Logic
Advantages and Disadvantages of PL
propositional logic is declarative
propositional logic allows partial, disjunctive, and
negated information unlike most data structures
and databases
propositional logic is compositional meaning of
s
Chapter 1
Introduction
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Theyre in PowerPoint form so you can add, modify, and delete slides
(including this one) and slide content to suit
Chapter 1
Introduction
A note on the use of these ppt slides:
Were making these slides freely available to all (faculty, students, readers).
Theyre in PowerPoint form so you can add, modify, and delete slides
(including this one) and slide content to suit
Horn Clause Inference
Horn Clauses
we know that all PL (and FOL) sentences can be expressed in CNF (i.e. a set of
disjunctive clauses, conjoined together)
some of these will have at most one positive literal per clause: Horn Clauses
if zero positives (p q
Rule-Based
Expert Systems
Rule-Based Systems
rule-based systems are structured as two memories
knowledge base of rules
working memory of facts
these can be logic based and use unication to determine rule satisfaction
rules = denite horn clauses (multiple
Improving Rule-Based
System Performance
Performance and Parallelism
many patterns and many facts result often result in
poor performance of rule-based systems, even
with state-saving algorithms such as rete
since rule bases are collections of unordered
ru
Uncertainty and
Bayess Rule
Logic Theory vs
Decision Theory
in propositional logic, propositional variables can
be true or false in different models
in probabilistic decision theory, propositional
variables have associated probabilities
probabilities assi
Adversarial Search
Chapter 6
Section 1 4
Outline
Optimal decisions
- pruning
Imperfect, real-time decisions
Games vs. search problems
"Unpredictable" opponent specifying a
move for every possible opponent reply
Time limits unlikely to find goal, must
ELEN E6776: Content Distribution Networks
Instructor: Anwar Walid
Lecture 7
Status of Presentation Wiki
-Network Coding
- Avalanche: BitTorrent + Network Coding
- Introduction to DHTs
E. Soljanin
Avalanche: BitTorrent + Network Coding
The Problem of Effic