Introduction to AI

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Introduction to AI
Russell and Norvig:
Chapters 1 and 2
Found on the Web …
AI
is the reproduction of the methods of
Intelligent
behavior
human
reasoning or intuition
Computer
Using computational models
to simulate
intelligent (human) behavior and
processes
AI is the study of mental faculties
through the Humans
use computational methods
Introduction to AI
2
I personally think that AI started as a
rebellion against some form of establishment
telling us “Computers cannot perform certain
tasks requiring intelligence”
For example, for many years AI researchers
have regarded computational complexity
theory as irrelevant to their field.
They eventually had to reckon with it, but in
the meantime computational complexity had
also changed a lot.
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What is AI?
Discipline that systematizes and automates
intellectual tasks to create machines that:
Act like humans
Act rationally
Think like humans
Think rationally
Introduction to AI
4
Act Like Humans
AI is the art of creating machines that
perform functions that require
intelligence when performed by humans
Methodology: Take an intellectual task
at which people are better and make a
computer do it •Prove a theorem
•Play chess
Turing test
•Plan a surgical operation
•Diagnose a disease
•Navigate
in
a
building
Introduction to AI
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Chess
Name: Garry Kasparov
Title: World Chess
Champion
Crime: Valued greed
over common sense
Humans are still better at making up excuses.
© Jonathan Schaeffer
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Perspective on Chess: Pro
“Saying Deep Blue doesn’t really think
about chess is like saying an airplane
doesn't really fly because it doesn't flap
its wings”
Drew McDermott
© Jonathan Schaeffer
Introduction to AI
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나비가 나는 이유?
나비는 유체역학적으로 날 수가 없다. 그러나
나비는 그 사실을 모르기 때문에 날 수 있다.
나비는 유체역학적으로 날기에 부적합하다.
제비는 적합하다. 그러나 나비는 제비
못지않게 잘 번성하고 있다.
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나비처럼 나는 것도 이유가 있다.
어떤 나비는 미국에서 호주까지 날아가기도 한다.
흉내보다는 같은 기능을 하면 충분!!
 두 발로 걷는 로봇 ? 지네 같은 로봇 ?
Introduction to AI
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Perspective on Chess: Con
“Chess is the Drosophila of artificial
intelligence. However, computer chess has
developed much as genetics might have if the
geneticists had concentrated their efforts
starting in 1910 on breeding racing Drosophila.
We would have some science, but mainly we
would have very fast fruit flies.”
John McCarthy
© Jonathan Schaeffer
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Think Like Humans
How the computer performs functions
does matter
Comparison of the traces of the
reasoning steps
Cognitive science  testable theories of
the workings of the human mind
But, do we want to duplicate human imperfections?
Introduction to AI
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Think/Act Rationally
Always make the best decision given what is
available (knowledge, time, resources)
•Connection
to economics,
A performance
measure operational
is required research,
and
control theory
 객관적인가?
청소로봇, 보상(reward)
디자이너의
•But ignores
role평가기준?
of consciousness, emotions,
 자원의 제한이 있을 때?
fear
of dying on intelligence
Perfect knowledge, unlimited resources 
logical reasoning
Imperfect knowledge, limited resources 
(limited) rationality
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Bits of History
1956: The name “Artificial Intelligence”
was coined. (Would “computational
rationality” have been better?)
Early period (50’s to late 60’s):
Basic principles and generality
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General problem solving
Theorem proving
Games
Formal calculus
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Bits of History
1969-1971: Shakey the
robot (Fikes, Hart, Nilsson)
Logic-based planning
(STRIPS)
Motion planning (visibility
graph)
Inductive learning (PLANEX)
Computer vision
Introduction to AI
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Bits of History
Knowledge-is-Power period (late 60’s to
mid 80’s):
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Focus on narrow tasks require expertise
Encoding of expertise in rule form:
If:
the car has off-highway tires and
4-wheel drive and
high ground clearance
Then: the car can traverse difficult terrain (0.8)

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Knowledge engineering
5th generation computer project
CYC system (Lenat)
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Bits of History
AI becomes an industry (80’s – present):
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Expert systems: Digital Equipment,
Teknowledge, Intellicorp, Du Pont, oil
industry, …
Lisp machines: LMI, Symbolics, …
Constraint programming: ILOG
Robotics: Machine Intelligence Corporation,
Adept, GMF (Fanuc), ABB, …
Speech understanding
Introduction to AI
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Bits of History
The return of neural networks, genetic
algorithms, and artificial life (80’s – 90’s)
Increased connection with economics,
operational research, and control theory
(90’s – present)
AI becomes less philosophical, more
technical and mathematically oriented
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Predictions and Reality … (1/3)
In the 60’s, a famous AI professor from MIT
said: “At the end of the summer, we will have
developed an electronic eye”
As of 2002, there is still no general computer
vision system capable of understanding
complex dynamic scenes
But computer systems routinely perform road
traffic monitoring, facial recognition, some
medical image analysis, part inspection, etc…
Introduction to AI
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Predictions and Reality … (2/3)
In 1958, Herbert Simon (CMU) predicted
that within 10 years a computer would
be Chess champion
This prediction became true in 1998
Today, computers have won over world
champions in several games, including
Checkers, Othello, and Chess, but still do
not do well in Go
Introduction to AI
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Predictions and Reality … (3/3)
In the 70’s, many believed that computer-controlled
robots would soon be everywhere from manufacturing
plants to home
Today, some industries (automobile, electronics) are
highly robotized, but home robots are still a thing of
the future
But robots have rolled on Mars, others are performing
brain and heart surgery, and humanoid robots are
operational and available for rent (see:
http://world.honda.com/news/2001/c011112.html)
Introduction to AI
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Mistakes …
Often, the potential of a new field is
over-estimated in its early age, but
under-estimated over the longer term
AI proponents have over-estimated the
need for smart software, and underestimated the feasibility and potential of
large software systems based on
massive coding effort
Introduction to AI
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생물학적으로 본 인간
인류의 진화
뇌의 크기
언어의 사용
도구의 사용
직립보행
사회생활
예측에 의한 행동
?
Introduction to AI
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본능인가 학습인가?
각인
언어능력
모국어
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인간과 다른 유인원
Introduction to AI
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Sahelanthropus tchadensis
뇌의 진화과정
원인류
네안데르탈 인
Homo sapiens
1300-1700 cc
600만
500만
400만
300만
유럽인
100만
200만
아프리카인
오스트랄로 피테쿠스
뇌용적 :
400-500 cc
Homo habilus
(handy man)
600-800 cc
Homo erectus
동아시아인
800-1200 cc
호주 원주민
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뇌의 용량
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인류의 진화
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Human Brain
Chimpanzee Brain
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보복전쟁 원인은 진화덜된 두뇌탓
미국 폴 로스코 교수 주장
미국 과학진흥협회 (AAAS) annual meeting
“핵 기술을 보유한 인간의 두뇌가 여전히 석기 시대 수준에 머물러 있다”
“자신뿐 아니라 자기 종족까지 죽이는
‘복수’ 행위는
정상적인 진화의 산물이 아니다”
Introduction
to AI
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일란성 쌍둥이 연구
건선
강한 유전자 영향
우울병
정신분열병
IQ
신경증
당뇨병
천식
심장병
암
다발성 경화증
Introduction to AI
약한 유전자 영향
29
언어의 진화
Introduction to AI
30
'Speech Gene' Tied to Modern Humans
FOXP2 gene
- first identified by Monaco’s group at Oxford University (Science 2001)
- 715 amino acids, two amino acid mutation in human lineage since 6 million years ago –
fixed at 120,000 – 200,000 years ago (Svante Paabo, Nature 2002)
Evolutionary leap. One of these primates is able to talk about what
he's seeing; the other isn't. Introduction to AI
31
언어를 관할하는 FOXP2 유전자의 돌연변이
Introduction to AI
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유전자의 영향
IQ
(어머니와 아들)
모성애 (아버지와 딸 (NAST))
도파민 D4 수용체(11번 염색체)
• 3번 exon(long) : 창조성, 탐구성, 스릴 추구
• 3번 exon(short) : 완고, 융통성 결여
• D4 장애 : 정신분열병
Introduction to AI
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아인슈타인의 뇌
Introduction to AI
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폭력의 생물학
Richard J. Davidson et al., Science 2000
(폭력과 전전두엽 장애 – 세로토닌 신경계 장애)
연쇄살인자 – 세로토닌 장애 – 책임문제
Introduction to AI
정신분열병 – 도파민 장애 – 살인 - 면죄부
35
생체 전자 공학
기록전극 부분의 확대도
전극의 전체 레이아웃
배양을 시작한 직후의 신경세포종의 모습
배양 후 2일이 경과한 신경세포종의 모습
Introduction to AI
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생체전자공학
뇌에 기계 또는 전자적 연결


눈 수술
귀 수술
Introduction to AI
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뇌의 특정 유전자 과도 발현하는 형질 전환 마우스 제조
(smart mice)
T. V. P. BLISS et al., Nature,1999
transgenic mice overexpressing
the NR2B subunit of the NMDA
receptor
Introduction
to AI
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최초의 유전자 치료술 (중증 복합 면역결핍증, SCID)
Introduction to AI
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Mistakes …
Often, the potential of a new field is over-estimated
in its early age, but under-estimated over the longer
term
What about Bio-informatics?

줄기세포의 치료효과
 쥐의 실험에 의하면 척추장애를 완벽히 치료
 그러나 저항력이 없는 쥐에서는 바로 암으로 전이, 있을 때에도
3개월 뒤면 암으로 전이
? 탄소 큐브 (나노기술)
 완벽한 새로운 물질
 인류는 경험하지 못했으며, 가장 무서운 발암물질?
핵, 유전자변형???
Introduction to AI
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Intelligent Agent
인간의 능력을 대신할 수 있는
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부분적: 걷는? 말하는? 판단하는?
인간과 같은?
지능적 능력을 가진
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인간과 다른 형태의?
말하는 개? 말하는 앵무새? 덧셈을 하는 개?
비교: SOAP, Service-oriented approach, XML,
Context, …
Introduction to AI
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Notion of an Agent
sensors
?
environment
agent
actuators
laser range
finder
sonars
Introduction to AI
touch sensors
42
Notion of an Agent
sensors
?
environment
agent
actuators
Introduction to AI
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Notion of an Agent
sensors
?
environment
agent
actuators
•Locality of sensors/actuators
•Imperfect modeling
•Time/resource constraints
•Sequential interaction
•Multi-agent
worlds
Introduction to AI
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단순화한 인공지능 문제
에이전트의 조건
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성공을 평가한 판단기준
환경 또는 응용영역에 대한 사전지식
Agent가 행할 수 있는 행위
현재까지 한 행위와 결과에 대한 인식
문제의 어려움
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Fully observable vs. Partially observable
Deterministic vs. Stochastic
Episodic vs. Sequential
Static vs. Dynamic
Discrete vs. Continuous
Single agent vs. Multiagent
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Example: Tracking a Target
• The robot must keep
the target in view
• The target’s trajectory
is not known in advance
• The robot may not know
all the obstacles in
advance
• Fast decision is required
robot
Introduction to AI
target
46
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