UNIT 4
PLANNING AND MACHINE
LEARNING
UNIT 4
PLANNING AND MACHINE
LEARNING
Planning
•Definition : Planning is arranging a sequence of
actions to achieve a goal.
•Uses core areas of AI like searching and reasoning &
•Is the core for areas like NLP, Computer Vision.
•Robotics
•Examples : Navigation , Manoeuvring, Language
Processing (Generation)
•Definition : Planning is arranging a sequence of
actions to achieve a goal.
•Uses core areas of AI like searching and reasoning &
•Is the core for areas like NLP, Computer Vision.
•Robotics
•Examples : Navigation , Manoeuvring, Language
Processing (Generation)
Kinematics (ME)
Planning (CSE)
Language & Planning
• Non-linguistic representation for sentences.
•Sentence generation
•Word order determination (Syntax planning)
E.g. I see movie ( English)
I movie see (Intermediate Language)
see
I movie
agent object
• Non-linguistic representation for sentences.
•Sentence generation
•Word order determination (Syntax planning)
E.g. I see movie ( English)
I movie see (Intermediate Language)
I movie
STRIPS
•Stanford Research Institute Problem Solver (1970s)
•Planning system for a robotics project : SHAKEY (by
Nilsson et.al.)
•Knowledge Representation : First Order Logic.
•Algorithm : Forward chaining on rules.
•Any search procedure : Finds a path from start to goal.
•Forward Chaining : Data-driven inferencing
•Backward Chaining : Goal-driven
•Stanford Research Institute Problem Solver (1970s)
•Planning system for a robotics project : SHAKEY (by
Nilsson et.al.)
•Knowledge Representation : First Order Logic.
•Algorithm : Forward chaining on rules.
•Any search procedure : Finds a path from start to goal.
•Forward Chaining : Data-driven inferencing
•Backward Chaining : Goal-driven
Example : Blocks World
•STRIPS : A planning system – Has rules with
precondition deletion list and addition list
A
C
A
C
B
B
START GOAL
Robot
hand
Robot
hand
START GOAL
Sequence of actions :
1. Grab C
2. Pickup C
3. Place on table C
4. Grab B
5. Pickup B
6. Stack B on C
7. Grab A
8. Pickup A
9. Stack A on B
Example : Blocks World
•Fundamental Problem :
The frame problem in AI is concerned with the question
of what piece of knowledge is relevant to the situation.
•Fundamental Assumption : Closed world assumption
If something is not asserted in the knowledge base, it is
assumed to be false.
(Also called “Negation by failure”)
•Fundamental Problem :
The frame problem in AI is concerned with the question
of what piece of knowledge is relevant to the situation.
•Fundamental Assumption : Closed world assumption
If something is not asserted in the knowledge base, it is
assumed to be false.
(Also called “Negation by failure”)
Example : Blocks World
•STRIPS : A planning system – Has rules with
precondition deletion list and addition list
A
C
A
C
B
B
START GOAL
Robot
hand
Robot
hand
on(B, table)
on(A, table)
on(C, A)
hand empty
clear(C)
clear(B)
on(C, table)
on(B, C)
on(A, B)
hand empty
clear(A)
START GOAL
Rules
•R1 : pickup(x)
Precondition & Deletion List : hand empty,
on(x,table), clear(x)
Add List : holding(x)
•R2 : putdown(x)
Precondition & Deletion List : holding(x)
Add List : hand empty, on(x,table), clear(x)
•R1 : pickup(x)
Precondition & Deletion List : hand empty,
on(x,table), clear(x)
Add List : holding(x)
•R2 : putdown(x)
Precondition & Deletion List : holding(x)
Add List : hand empty, on(x,table), clear(x)
Rules
•R3 : stack(x,y)
Precondition & Deletion List :holding(x), clear(y) Add
List : on(x,y), clear(x)
•R4 : unstack(x,y)
Precondition & Deletion List : on(x,y), clear(x)
Add List : holding(x), clear(y)
•R3 : stack(x,y)
Precondition & Deletion List :holding(x), clear(y) Add
List : on(x,y), clear(x)
•R4 : unstack(x,y)
Precondition & Deletion List : on(x,y), clear(x)
Add List : holding(x), clear(y)
Plan for the block world problem
• For the given problem, Start  Goal can be achieved
by the following sequence :
1. Unstack(C,A)
2. Putdown(C)
3. Pickup(B)
4. Stack(B,C)
5. Pickup(A)
6. Stack(A,B)
• Execution of a plan: achieved through a data structure
called Triangular Table.
• For the given problem, Start  Goal can be achieved
by the following sequence :
1. Unstack(C,A)
2. Putdown(C)
3. Pickup(B)
4. Stack(B,C)
5. Pickup(A)
6. Stack(A,B)
• Execution of a plan: achieved through a data structure
called Triangular Table.
Triangular Table
holding(C)
unstack(C,A)
putdown(C)
hand empty
on(B,table) pickup(B)
clear(C) holding(B) stack(B,C)
clear(C)
on(C,A)
hand empty
1
2
3
4 clear(C) holding(B) stack(B,C)
on(A,table) clear(A) hand empty pickup(A)
clear(B) holding(A) stack(A,B)
on(C,table) on(B,C) on(A,B)
clear(A)
0 1 2 3 4 5 6
4
5
6
7
Triangular Table
• For n operations in the plan, there are :
• (n+1) rows : 1  n+1
• (n+1) columns : 0  n
• At the end of the ith row, place the ith component of the plan.
• The row entries for the ith step contain the pre-conditions for the
ith operation.
• The column entries for the jth column contain the add list for the
rule on the top.
• The <i,j> th cell (where 1 ≤ i ≤ n+1 and 0≤ j ≤ n) contain the pre-
conditions for the ith operation that are added by the jth operation.
• The first column indicates the starting state and the last row
indicates the goal state.
• For n operations in the plan, there are :
• (n+1) rows : 1  n+1
• (n+1) columns : 0  n
• At the end of the ith row, place the ith component of the plan.
• The row entries for the ith step contain the pre-conditions for the
ith operation.
• The column entries for the jth column contain the add list for the
rule on the top.
• The <i,j> th cell (where 1 ≤ i ≤ n+1 and 0≤ j ≤ n) contain the pre-
conditions for the ith operation that are added by the jth operation.
• The first column indicates the starting state and the last row
indicates the goal state.
Search in case of planning
• Ex: Blocks world
• Triangular table leads
• to some amount of fault-tolerance in the robot
Start
S1 S2
Pickup(B) Unstack(C,A)
• Ex: Blocks world
• Triangular table leads
• to some amount of fault-tolerance in the robot
A
C
B
START
A C
B
A
C B
WRONG
MOVE
NOT ALLOWED
Resilience in Planning
• After a wrong operation, can the robot come back to
the right path ?
• i.e. after performing a wrong operation, if the system
again goes towards the goal, then it has resilience
w.r.t. that operation
• Advanced planning strategies
– Hierarchical planning
– Probabilistic planning
– Constraint satisfaction
• After a wrong operation, can the robot come back to
the right path ?
• i.e. after performing a wrong operation, if the system
again goes towards the goal, then it has resilience
w.r.t. that operation
• Advanced planning strategies
– Hierarchical planning
– Probabilistic planning
– Constraint satisfaction
K Strips
• Modal Operator K :
We are familiar with the use of connectives ∧
and V in logics.
• Thinking of these connectives as operators
that construct more complex formulas from
simpler components.
• Here, we want to construct a formula whose
intended meaning is that a certain agent
knows a certain proposition.
• Modal Operator K :
We are familiar with the use of connectives ∧
and V in logics.
• Thinking of these connectives as operators
that construct more complex formulas from
simpler components.
• Here, we want to construct a formula whose
intended meaning is that a certain agent
knows a certain proposition.
• The components consist of a term denoting
the agent and a formula denoting a
proposition that the agent knows.
• To accomplish this, modal operator K is
introduced.
• For example, to say that Robot (name of
agent) know that block A is on block B, then
write,
K( Robot, On(A,B))
K Strips
• The components consist of a term denoting
the agent and a formula denoting a
proposition that the agent knows.
• To accomplish this, modal operator K is
introduced.
• For example, to say that Robot (name of
agent) know that block A is on block B, then
write,
K( Robot, On(A,B))
K Strips
• The sentence formed by combining K with the
term Robot and the formula On(A,B) gets a
new formula, the intended meaning of which
is “Robot knows that block A is on block B”.
• The words “knows” and “belief” is different in
meaning.
• That means an agent can believe a false
proposition, but it cannot know anything that
is false.
• The sentence formed by combining K with the
term Robot and the formula On(A,B) gets a
new formula, the intended meaning of which
is “Robot knows that block A is on block B”.
• The words “knows” and “belief” is different in
meaning.
• That means an agent can believe a false
proposition, but it cannot know anything that
is false.
K Strips
• Some examples,
• K(Agent1, K(Agent2, On(A,B) ) ], means Agent1
knows that Agent1 knows that A is on B.
K(Agent1, On(A,B)) V K(Agent1, On(A,C) )
means that either Agent1 knows that A is on B
or it knows that A is on C.
• K(Agent1, On(A,B)) V K(Agent1, ¬On(A,B) )
means that either Agent1 knows whether or
not A is on B.
• Some examples,
• K(Agent1, K(Agent2, On(A,B) ) ], means Agent1
knows that Agent1 knows that A is on B.
K(Agent1, On(A,B)) V K(Agent1, On(A,C) )
means that either Agent1 knows that A is on B
or it knows that A is on C.
• K(Agent1, On(A,B)) V K(Agent1, ¬On(A,B) )
means that either Agent1 knows whether or
not A is on B.
K Strips
• Knowledge Axioms:
• The operators ∧ and V have compositional
semantics (depends on truth value) , but the
semantics of K are not compositional.
• The truth value of K(Agent1, On(A,B) ) for
example, cannot necessarily be determined
from the properties of K, the denotation of
Agent1 and the truth value of On(A,B).
• K Operator is said to be referentially opaque.
• Knowledge Axioms:
• The operators ∧ and V have compositional
semantics (depends on truth value) , but the
semantics of K are not compositional.
• The truth value of K(Agent1, On(A,B) ) for
example, cannot necessarily be determined
from the properties of K, the denotation of
Agent1 and the truth value of On(A,B).
• K Operator is said to be referentially opaque.
K Strips
• Example in Planning Speech Action:
• We can treat speech acts just like other agent
systems.
• Our agent can use a plan-generating system to
make plans comprising speech acts and other
actions.
• To do so, it needs a model of the effects of
these actions.
• Example in Planning Speech Action:
• We can treat speech acts just like other agent
systems.
• Our agent can use a plan-generating system to
make plans comprising speech acts and other
actions.
• To do so, it needs a model of the effects of
these actions.
K Strips
• Consider for example, Tell( A, φ ) , where A is
Agent and φ is true.
We could model the effects of that action by
the STRIPS rule :
• Tell( A, φ ) :
• Precondition : Next_to(A) ∧ φ ∧ ¬K(A, φ)
• Delete : ¬K(A, φ)
• Consider for example, Tell( A, φ ) , where A is
Agent and φ is true.
We could model the effects of that action by
the STRIPS rule :
• Tell( A, φ ) :
• Precondition : Next_to(A) ∧ φ ∧ ¬K(A, φ)
• Delete : ¬K(A, φ)
K Strips
• Add : K(A, φ)
• The precondition Next_to(A) ensures that our
agent is close to agent A to enable
communication.
• The precondition φ is imposed to ensure that
our agent actually believes φ before it can
inform another agent about the truth.
• The precondition ¬K(A, φ) ensure that our
agent does not communicate redundant
information.
• Add : K(A, φ)
• The precondition Next_to(A) ensures that our
agent is close to agent A to enable
communication.
• The precondition φ is imposed to ensure that
our agent actually believes φ before it can
inform another agent about the truth.
• The precondition ¬K(A, φ) ensure that our
agent does not communicate redundant
information.
Intelligence
• Intelligence
– Ability to solve problems
• Examples of Intelligent Behaviors or Tasks
– Classification of texts based on content
– Heart disease diagnosis
– Chess playing
• Intelligence
– Ability to solve problems
• Examples of Intelligent Behaviors or Tasks
– Classification of texts based on content
– Heart disease diagnosis
– Chess playing
Example 1: Text Classification (1)
Huge oil platforms dot the Gulf like beacons
-- usually lit up like Christmas trees at night.
One of them, sitting astride the Rostam
offshore oilfield, was all but blown out of
the water by U.S. Warships on Monday.
The Iranian platform, an unsightly mass of
steel and concrete, was a three-tier
structure rising 200 feet (60 metres) above
the warm waters of the Gulf until four U.S.
Destroyers pumped some …
Human
Judgment
Huge oil platforms dot the Gulf like beacons
-- usually lit up like Christmas trees at night.
One of them, sitting astride the Rostam
offshore oilfield, was all but blown out of
the water by U.S. Warships on Monday.
The Iranian platform, an unsightly mass of
steel and concrete, was a three-tier
structure rising 200 feet (60 metres) above
the warm waters of the Gulf until four U.S.
Destroyers pumped some …
Human
Judgment
Crude
Ship
Example 1: Text Classification (2)
The Federal Reserve is expected to enter the
government securities market to supply
reserves to the banking system via system
repurchase agreements, economists said.
Most economists said the Fed would
execute three-day system repurchases to
meet a substantial need to add reserves in
the current maintenance period, although
some said a more …
Human
Judgment
The Federal Reserve is expected to enter the
government securities market to supply
reserves to the banking system via system
repurchase agreements, economists said.
Most economists said the Fed would
execute three-day system repurchases to
meet a substantial need to add reserves in
the current maintenance period, although
some said a more …
Human
Judgment
Money-fx
Example 2: Disease Diagnosis (1)
Patient 1’s data
Age: 67
Sex: male
Chest pain type: asymptomatic
Resting blood pressure: 160mm Hg
Serum cholestoral: 286mg/dl
Fasting blood sugar: < 120mg/dl
…
Doctor
Diagnosis
Patient 1’s data
Age: 67
Sex: male
Chest pain type: asymptomatic
Resting blood pressure: 160mm Hg
Serum cholestoral: 286mg/dl
Fasting blood sugar: < 120mg/dl
…
Doctor
Diagnosis
Presence
Example 2: Disease Diagnosis (2)
Patient 2‘s data
Age: 63
Sex: male
Chest pain type: typical angina
Resting blood pressure: 145mm Hg
Serum cholestoral: 233mg/dl
Fasting blood sugar: > 120mg/dl
…
Doctor
Diagnosis
Patient 2‘s data
Age: 63
Sex: male
Chest pain type: typical angina
Resting blood pressure: 145mm Hg
Serum cholestoral: 233mg/dl
Fasting blood sugar: > 120mg/dl
…
Doctor
Diagnosis
Absence
Example 3: Chess Playing
• Chess Game
– Two players playing one-by-one under the
restriction of a certain rule
• Characteristics
– To achieve a goal: win the game
– Interactive
• Chess Game
– Two players playing one-by-one under the
restriction of a certain rule
• Characteristics
– To achieve a goal: win the game
– Interactive
Artificial Intelligence
• Artificial Intelligence
– Ability of machines in conducting intelligent
tasks
• Intelligent Programs
– Programs conducting specific intelligent tasks
• Artificial Intelligence
– Ability of machines in conducting intelligent
tasks
• Intelligent Programs
– Programs conducting specific intelligent tasks
Input
Intelligent
Processing
Output
Example 1: Text Classifier (1)
…
fiber = 0
…
huge = 1
…
oil = 1
platforms = 1
…
Classification
…
Crude = 1
…
Money-fx = 0
…
Ship = 1
…
Text File:
Huge oil
platforms dot
the Gulf like
beacons --
usually lit up …
Preprocessing
…
fiber = 0
…
huge = 1
…
oil = 1
platforms = 1
…
Classification
…
Crude = 1
…
Money-fx = 0
…
Ship = 1
…
Text File:
Huge oil
platforms dot
the Gulf like
beacons --
usually lit up …
Preprocessing
Example 1: Text Classifier (2)
…
enter = 1
expected = 1
…
federal = 1
…
oil = 0
…
Classification
…
Crude = 0
…
Money-fx = 1
…
Ship = 0
…
Text File:
The Federal
Reserve is
expected to
enter the
government …
Preprocessing
…
enter = 1
expected = 1
…
federal = 1
…
oil = 0
…
Classification
…
Crude = 0
…
Money-fx = 1
…
Ship = 0
…
Text File:
The Federal
Reserve is
expected to
enter the
government …
Preprocessing
Example 2: Disease Classifier (1)
Preprocessed data of patient 1
Age = 67
Sex = 1
Chest pain type = 4
Resting blood pressure = 160
Serum cholestoral = 286
Fasting blood sugar = 0
…
Classification
Preprocessed data of patient 1
Age = 67
Sex = 1
Chest pain type = 4
Resting blood pressure = 160
Serum cholestoral = 286
Fasting blood sugar = 0
…
Classification
Presence = 1
Example 2: Disease Classifier (2)
Preprocessed data of patient 2
Age = 63
Sex = 1
Chest pain type = 1
Resting blood pressure = 145
Serum cholestoral = 233
Fasting blood sugar = 1
…
Classification
Preprocessed data of patient 2
Age = 63
Sex = 1
Chest pain type = 1
Resting blood pressure = 145
Serum cholestoral = 233
Fasting blood sugar = 1
…
Classification
Presence = 0
Example 3: Chess Program
Searching and
evaluating
Best move -New
matrix
Opponent’s
playing his move
Matrix representing the
current board
AI Approach
• Reasoning with Knowledge
– Knowledge base
– Reasoning
• Traditional Approaches
– Handcrafted knowledge base
– Complex reasoning process
– Disadvantages
• Knowledge acquisition bottleneck
• Reasoning with Knowledge
– Knowledge base
– Reasoning
• Traditional Approaches
– Handcrafted knowledge base
– Complex reasoning process
– Disadvantages
• Knowledge acquisition bottleneck
Machine Learning
• Machine Learning (Mitchell 1997)
– Learn from past experiences
– Improve the performances of intelligent
programs
• Definitions (Mitchell 1997)
– A computer program is said to learn from
experience E with respect to some class of
tasks T and performance measure P, if its
performance at the tasks improves with the
experiences
• Machine Learning (Mitchell 1997)
– Learn from past experiences
– Improve the performances of intelligent
programs
• Definitions (Mitchell 1997)
– A computer program is said to learn from
experience E with respect to some class of
tasks T and performance measure P, if its
performance at the tasks improves with the
experiences
Example 1: Text Classification
Classified text files
Text file 1 trade
Text file 2 ship
… …
Text classifier
New text file class
Classified text files
Text file 1 trade
Text file 2 ship
… …
Training
Example 2: Disease Diagnosis
Database of medical records
Patient 1’s data Absence
Patient 2’s data Presence
… …
Disease classifier
New patient’s
data
Presence or
absence
Database of medical records
Patient 1’s data Absence
Patient 2’s data Presence
… …
Training
Example 3: Chess Playing
Games played:
Game 1’s move list Win
Game 2’s move list Lose
… …
Strategy of
Searching and
Evaluating
New matrix
representing the
current board
Best move
Games played:
Game 1’s move list Win
Game 2’s move list Lose
… …
Training
Examples
• Text Classification
– Task T
• Assigning texts to a set of predefined categories
– Performance measure P
• Precision and recall of each category
– Training experiences E
• A database of texts with their corresponding
categories
• How about Disease Diagnosis?
• How about Chess Playing?
• Text Classification
– Task T
• Assigning texts to a set of predefined categories
– Performance measure P
• Precision and recall of each category
– Training experiences E
• A database of texts with their corresponding
categories
• How about Disease Diagnosis?
• How about Chess Playing?
Why Machine Learning Is Possible?
• Mass Storage
– More data available
• Higher Performance of Computer
– Larger memory in handling the data
– Greater computational power for calculating
and even online learning
• Mass Storage
– More data available
• Higher Performance of Computer
– Larger memory in handling the data
– Greater computational power for calculating
and even online learning
Advantages
• Alleviate Knowledge Acquisition Bottleneck
– Does not require knowledge engineers
– Scalable in constructing knowledge base
• Adaptive
– Adaptive to the changing conditions
– Easy in migrating to new domains
• Alleviate Knowledge Acquisition Bottleneck
– Does not require knowledge engineers
– Scalable in constructing knowledge base
• Adaptive
– Adaptive to the changing conditions
– Easy in migrating to new domains
Success of Machine Learning
• Almost All the Learning Algorithms
– Text classification (Dumais et al. 1998)
– Gene or protein classification optionally with
feature engineering (Bhaskar et al. 2006)
• Reinforcement Learning
– Backgammon (Tesauro 1995)
• Learning of Sequence Labeling
– Speech recognition (Lee 1989)
– Part-of-speech tagging (Church 1988)
• Almost All the Learning Algorithms
– Text classification (Dumais et al. 1998)
– Gene or protein classification optionally with
feature engineering (Bhaskar et al. 2006)
• Reinforcement Learning
– Backgammon (Tesauro 1995)
• Learning of Sequence Labeling
– Speech recognition (Lee 1989)
– Part-of-speech tagging (Church 1988)
Adaptive Learning
Adaptive Learning Basics
• A system which collects user information and behavioral
data to customize a learning experience for an individual
• Encourages active participation rather than passive
receptacle
• Moves away from static hypermedia (same page content
and links for all users)
• Artificial Intelligence movement
• A system which collects user information and behavioral
data to customize a learning experience for an individual
• Encourages active participation rather than passive
receptacle
• Moves away from static hypermedia (same page content
and links for all users)
• Artificial Intelligence movement
This…
Not this…
Machine Learning
• Machine collects data and recognizes patterns in the
data
• Algorithms – sequence of instructions to transform
the input into output
• Intelligent systems have the ability to learn in a
changing environment
• Machine collects data and recognizes patterns in the
data
• Algorithms – sequence of instructions to transform
the input into output
• Intelligent systems have the ability to learn in a
changing environment
Adaptation Process
• Data collection
– User interaction
– Direct input
• Interpret data using models
• Infer user requirements and preferences
• Tailored aggregation
• Presentation of tailored content (adaptive
effect)
• Synthesis with population data
• Data collection
– User interaction
– Direct input
• Interpret data using models
• Infer user requirements and preferences
• Tailored aggregation
• Presentation of tailored content (adaptive
effect)
• Synthesis with population data
Adaptation Process
Modeling
Categories of Adaptation
• Interaction with the system
• Course/object delivery
• Content adaptation
• Collaborative/social support
• Interaction with the system
• Course/object delivery
• Content adaptation
• Collaborative/social support
Content Adaptation
• Adaptive presentation
– content of a hypermedia page adapted to the user’s
goals, knowledge and other information
• Adaptive navigation
– link presentation and functionality adapted to the
goals, knowledge and characteristics of the user
• Direct guidance
• Link sorting
• Link annotation
• Link hiding
• Adaptive presentation
– content of a hypermedia page adapted to the user’s
goals, knowledge and other information
• Adaptive navigation
– link presentation and functionality adapted to the
goals, knowledge and characteristics of the user
• Direct guidance
• Link sorting
• Link annotation
• Link hiding
Assessment
• System feedback
• Embedded assessment
• Adaptive
– Timing/architecture
– Question level
• System feedback
• Embedded assessment
• Adaptive
– Timing/architecture
– Question level
Examples
• Adaptive eLearning Research Group
• AHA!
• Andes Physics Tutor
• ELM-ART
• GRE
• iKnow!
• Learnthat
• Khan Academy
• Knewton
• Adaptive eLearning Research Group
• AHA!
• Andes Physics Tutor
• ELM-ART
• GRE
• iKnow!
• Learnthat
• Khan Academy
• Knewton
Adaptive vs machine learning
• An adaptive system is a set of interacting or interdependent entities, real
or abstract, forming an integrated whole that together are able to respond
to environmental changes or changes in the interacting parts. Feedback
loops represent a key feature of adaptive systems, allowing the response
to changes; examples of adaptive systems include: natural ecosystems,
individual organisms, human communities, human organizations, and
human families.
• Some artificial systems can be adaptive as well; for instance, robots
employ control systems that utilize feedback loops to sense new
conditions in their environment and adapt accordingly.
• An adaptive system is a set of interacting or interdependent entities, real
or abstract, forming an integrated whole that together are able to respond
to environmental changes or changes in the interacting parts. Feedback
loops represent a key feature of adaptive systems, allowing the response
to changes; examples of adaptive systems include: natural ecosystems,
individual organisms, human communities, human organizations, and
human families.
• Some artificial systems can be adaptive as well; for instance, robots
employ control systems that utilize feedback loops to sense new
conditions in their environment and adapt accordingly.
UNIT 4 ENDS!!!

CS1017-unitIV.pdf

  • 1.
    UNIT 4 PLANNING ANDMACHINE LEARNING UNIT 4 PLANNING AND MACHINE LEARNING
  • 2.
    Planning •Definition : Planningis arranging a sequence of actions to achieve a goal. •Uses core areas of AI like searching and reasoning & •Is the core for areas like NLP, Computer Vision. •Robotics •Examples : Navigation , Manoeuvring, Language Processing (Generation) •Definition : Planning is arranging a sequence of actions to achieve a goal. •Uses core areas of AI like searching and reasoning & •Is the core for areas like NLP, Computer Vision. •Robotics •Examples : Navigation , Manoeuvring, Language Processing (Generation) Kinematics (ME) Planning (CSE)
  • 3.
    Language & Planning •Non-linguistic representation for sentences. •Sentence generation •Word order determination (Syntax planning) E.g. I see movie ( English) I movie see (Intermediate Language) see I movie agent object • Non-linguistic representation for sentences. •Sentence generation •Word order determination (Syntax planning) E.g. I see movie ( English) I movie see (Intermediate Language) I movie
  • 4.
    STRIPS •Stanford Research InstituteProblem Solver (1970s) •Planning system for a robotics project : SHAKEY (by Nilsson et.al.) •Knowledge Representation : First Order Logic. •Algorithm : Forward chaining on rules. •Any search procedure : Finds a path from start to goal. •Forward Chaining : Data-driven inferencing •Backward Chaining : Goal-driven •Stanford Research Institute Problem Solver (1970s) •Planning system for a robotics project : SHAKEY (by Nilsson et.al.) •Knowledge Representation : First Order Logic. •Algorithm : Forward chaining on rules. •Any search procedure : Finds a path from start to goal. •Forward Chaining : Data-driven inferencing •Backward Chaining : Goal-driven
  • 5.
    Example : BlocksWorld •STRIPS : A planning system – Has rules with precondition deletion list and addition list A C A C B B START GOAL Robot hand Robot hand START GOAL Sequence of actions : 1. Grab C 2. Pickup C 3. Place on table C 4. Grab B 5. Pickup B 6. Stack B on C 7. Grab A 8. Pickup A 9. Stack A on B
  • 6.
    Example : BlocksWorld •Fundamental Problem : The frame problem in AI is concerned with the question of what piece of knowledge is relevant to the situation. •Fundamental Assumption : Closed world assumption If something is not asserted in the knowledge base, it is assumed to be false. (Also called “Negation by failure”) •Fundamental Problem : The frame problem in AI is concerned with the question of what piece of knowledge is relevant to the situation. •Fundamental Assumption : Closed world assumption If something is not asserted in the knowledge base, it is assumed to be false. (Also called “Negation by failure”)
  • 7.
    Example : BlocksWorld •STRIPS : A planning system – Has rules with precondition deletion list and addition list A C A C B B START GOAL Robot hand Robot hand on(B, table) on(A, table) on(C, A) hand empty clear(C) clear(B) on(C, table) on(B, C) on(A, B) hand empty clear(A) START GOAL
  • 8.
    Rules •R1 : pickup(x) Precondition& Deletion List : hand empty, on(x,table), clear(x) Add List : holding(x) •R2 : putdown(x) Precondition & Deletion List : holding(x) Add List : hand empty, on(x,table), clear(x) •R1 : pickup(x) Precondition & Deletion List : hand empty, on(x,table), clear(x) Add List : holding(x) •R2 : putdown(x) Precondition & Deletion List : holding(x) Add List : hand empty, on(x,table), clear(x)
  • 9.
    Rules •R3 : stack(x,y) Precondition& Deletion List :holding(x), clear(y) Add List : on(x,y), clear(x) •R4 : unstack(x,y) Precondition & Deletion List : on(x,y), clear(x) Add List : holding(x), clear(y) •R3 : stack(x,y) Precondition & Deletion List :holding(x), clear(y) Add List : on(x,y), clear(x) •R4 : unstack(x,y) Precondition & Deletion List : on(x,y), clear(x) Add List : holding(x), clear(y)
  • 10.
    Plan for theblock world problem • For the given problem, Start  Goal can be achieved by the following sequence : 1. Unstack(C,A) 2. Putdown(C) 3. Pickup(B) 4. Stack(B,C) 5. Pickup(A) 6. Stack(A,B) • Execution of a plan: achieved through a data structure called Triangular Table. • For the given problem, Start  Goal can be achieved by the following sequence : 1. Unstack(C,A) 2. Putdown(C) 3. Pickup(B) 4. Stack(B,C) 5. Pickup(A) 6. Stack(A,B) • Execution of a plan: achieved through a data structure called Triangular Table.
  • 11.
    Triangular Table holding(C) unstack(C,A) putdown(C) hand empty on(B,table)pickup(B) clear(C) holding(B) stack(B,C) clear(C) on(C,A) hand empty 1 2 3 4 clear(C) holding(B) stack(B,C) on(A,table) clear(A) hand empty pickup(A) clear(B) holding(A) stack(A,B) on(C,table) on(B,C) on(A,B) clear(A) 0 1 2 3 4 5 6 4 5 6 7
  • 12.
    Triangular Table • Forn operations in the plan, there are : • (n+1) rows : 1  n+1 • (n+1) columns : 0  n • At the end of the ith row, place the ith component of the plan. • The row entries for the ith step contain the pre-conditions for the ith operation. • The column entries for the jth column contain the add list for the rule on the top. • The <i,j> th cell (where 1 ≤ i ≤ n+1 and 0≤ j ≤ n) contain the pre- conditions for the ith operation that are added by the jth operation. • The first column indicates the starting state and the last row indicates the goal state. • For n operations in the plan, there are : • (n+1) rows : 1  n+1 • (n+1) columns : 0  n • At the end of the ith row, place the ith component of the plan. • The row entries for the ith step contain the pre-conditions for the ith operation. • The column entries for the jth column contain the add list for the rule on the top. • The <i,j> th cell (where 1 ≤ i ≤ n+1 and 0≤ j ≤ n) contain the pre- conditions for the ith operation that are added by the jth operation. • The first column indicates the starting state and the last row indicates the goal state.
  • 13.
    Search in caseof planning • Ex: Blocks world • Triangular table leads • to some amount of fault-tolerance in the robot Start S1 S2 Pickup(B) Unstack(C,A) • Ex: Blocks world • Triangular table leads • to some amount of fault-tolerance in the robot A C B START A C B A C B WRONG MOVE NOT ALLOWED
  • 14.
    Resilience in Planning •After a wrong operation, can the robot come back to the right path ? • i.e. after performing a wrong operation, if the system again goes towards the goal, then it has resilience w.r.t. that operation • Advanced planning strategies – Hierarchical planning – Probabilistic planning – Constraint satisfaction • After a wrong operation, can the robot come back to the right path ? • i.e. after performing a wrong operation, if the system again goes towards the goal, then it has resilience w.r.t. that operation • Advanced planning strategies – Hierarchical planning – Probabilistic planning – Constraint satisfaction
  • 15.
    K Strips • ModalOperator K : We are familiar with the use of connectives ∧ and V in logics. • Thinking of these connectives as operators that construct more complex formulas from simpler components. • Here, we want to construct a formula whose intended meaning is that a certain agent knows a certain proposition. • Modal Operator K : We are familiar with the use of connectives ∧ and V in logics. • Thinking of these connectives as operators that construct more complex formulas from simpler components. • Here, we want to construct a formula whose intended meaning is that a certain agent knows a certain proposition.
  • 16.
    • The componentsconsist of a term denoting the agent and a formula denoting a proposition that the agent knows. • To accomplish this, modal operator K is introduced. • For example, to say that Robot (name of agent) know that block A is on block B, then write, K( Robot, On(A,B)) K Strips • The components consist of a term denoting the agent and a formula denoting a proposition that the agent knows. • To accomplish this, modal operator K is introduced. • For example, to say that Robot (name of agent) know that block A is on block B, then write, K( Robot, On(A,B))
  • 17.
    K Strips • Thesentence formed by combining K with the term Robot and the formula On(A,B) gets a new formula, the intended meaning of which is “Robot knows that block A is on block B”. • The words “knows” and “belief” is different in meaning. • That means an agent can believe a false proposition, but it cannot know anything that is false. • The sentence formed by combining K with the term Robot and the formula On(A,B) gets a new formula, the intended meaning of which is “Robot knows that block A is on block B”. • The words “knows” and “belief” is different in meaning. • That means an agent can believe a false proposition, but it cannot know anything that is false.
  • 18.
    K Strips • Someexamples, • K(Agent1, K(Agent2, On(A,B) ) ], means Agent1 knows that Agent1 knows that A is on B. K(Agent1, On(A,B)) V K(Agent1, On(A,C) ) means that either Agent1 knows that A is on B or it knows that A is on C. • K(Agent1, On(A,B)) V K(Agent1, ¬On(A,B) ) means that either Agent1 knows whether or not A is on B. • Some examples, • K(Agent1, K(Agent2, On(A,B) ) ], means Agent1 knows that Agent1 knows that A is on B. K(Agent1, On(A,B)) V K(Agent1, On(A,C) ) means that either Agent1 knows that A is on B or it knows that A is on C. • K(Agent1, On(A,B)) V K(Agent1, ¬On(A,B) ) means that either Agent1 knows whether or not A is on B.
  • 19.
    K Strips • KnowledgeAxioms: • The operators ∧ and V have compositional semantics (depends on truth value) , but the semantics of K are not compositional. • The truth value of K(Agent1, On(A,B) ) for example, cannot necessarily be determined from the properties of K, the denotation of Agent1 and the truth value of On(A,B). • K Operator is said to be referentially opaque. • Knowledge Axioms: • The operators ∧ and V have compositional semantics (depends on truth value) , but the semantics of K are not compositional. • The truth value of K(Agent1, On(A,B) ) for example, cannot necessarily be determined from the properties of K, the denotation of Agent1 and the truth value of On(A,B). • K Operator is said to be referentially opaque.
  • 20.
    K Strips • Examplein Planning Speech Action: • We can treat speech acts just like other agent systems. • Our agent can use a plan-generating system to make plans comprising speech acts and other actions. • To do so, it needs a model of the effects of these actions. • Example in Planning Speech Action: • We can treat speech acts just like other agent systems. • Our agent can use a plan-generating system to make plans comprising speech acts and other actions. • To do so, it needs a model of the effects of these actions.
  • 21.
    K Strips • Considerfor example, Tell( A, φ ) , where A is Agent and φ is true. We could model the effects of that action by the STRIPS rule : • Tell( A, φ ) : • Precondition : Next_to(A) ∧ φ ∧ ¬K(A, φ) • Delete : ¬K(A, φ) • Consider for example, Tell( A, φ ) , where A is Agent and φ is true. We could model the effects of that action by the STRIPS rule : • Tell( A, φ ) : • Precondition : Next_to(A) ∧ φ ∧ ¬K(A, φ) • Delete : ¬K(A, φ)
  • 22.
    K Strips • Add: K(A, φ) • The precondition Next_to(A) ensures that our agent is close to agent A to enable communication. • The precondition φ is imposed to ensure that our agent actually believes φ before it can inform another agent about the truth. • The precondition ¬K(A, φ) ensure that our agent does not communicate redundant information. • Add : K(A, φ) • The precondition Next_to(A) ensures that our agent is close to agent A to enable communication. • The precondition φ is imposed to ensure that our agent actually believes φ before it can inform another agent about the truth. • The precondition ¬K(A, φ) ensure that our agent does not communicate redundant information.
  • 23.
    Intelligence • Intelligence – Abilityto solve problems • Examples of Intelligent Behaviors or Tasks – Classification of texts based on content – Heart disease diagnosis – Chess playing • Intelligence – Ability to solve problems • Examples of Intelligent Behaviors or Tasks – Classification of texts based on content – Heart disease diagnosis – Chess playing
  • 24.
    Example 1: TextClassification (1) Huge oil platforms dot the Gulf like beacons -- usually lit up like Christmas trees at night. One of them, sitting astride the Rostam offshore oilfield, was all but blown out of the water by U.S. Warships on Monday. The Iranian platform, an unsightly mass of steel and concrete, was a three-tier structure rising 200 feet (60 metres) above the warm waters of the Gulf until four U.S. Destroyers pumped some … Human Judgment Huge oil platforms dot the Gulf like beacons -- usually lit up like Christmas trees at night. One of them, sitting astride the Rostam offshore oilfield, was all but blown out of the water by U.S. Warships on Monday. The Iranian platform, an unsightly mass of steel and concrete, was a three-tier structure rising 200 feet (60 metres) above the warm waters of the Gulf until four U.S. Destroyers pumped some … Human Judgment Crude Ship
  • 25.
    Example 1: TextClassification (2) The Federal Reserve is expected to enter the government securities market to supply reserves to the banking system via system repurchase agreements, economists said. Most economists said the Fed would execute three-day system repurchases to meet a substantial need to add reserves in the current maintenance period, although some said a more … Human Judgment The Federal Reserve is expected to enter the government securities market to supply reserves to the banking system via system repurchase agreements, economists said. Most economists said the Fed would execute three-day system repurchases to meet a substantial need to add reserves in the current maintenance period, although some said a more … Human Judgment Money-fx
  • 26.
    Example 2: DiseaseDiagnosis (1) Patient 1’s data Age: 67 Sex: male Chest pain type: asymptomatic Resting blood pressure: 160mm Hg Serum cholestoral: 286mg/dl Fasting blood sugar: < 120mg/dl … Doctor Diagnosis Patient 1’s data Age: 67 Sex: male Chest pain type: asymptomatic Resting blood pressure: 160mm Hg Serum cholestoral: 286mg/dl Fasting blood sugar: < 120mg/dl … Doctor Diagnosis Presence
  • 27.
    Example 2: DiseaseDiagnosis (2) Patient 2‘s data Age: 63 Sex: male Chest pain type: typical angina Resting blood pressure: 145mm Hg Serum cholestoral: 233mg/dl Fasting blood sugar: > 120mg/dl … Doctor Diagnosis Patient 2‘s data Age: 63 Sex: male Chest pain type: typical angina Resting blood pressure: 145mm Hg Serum cholestoral: 233mg/dl Fasting blood sugar: > 120mg/dl … Doctor Diagnosis Absence
  • 28.
    Example 3: ChessPlaying • Chess Game – Two players playing one-by-one under the restriction of a certain rule • Characteristics – To achieve a goal: win the game – Interactive • Chess Game – Two players playing one-by-one under the restriction of a certain rule • Characteristics – To achieve a goal: win the game – Interactive
  • 29.
    Artificial Intelligence • ArtificialIntelligence – Ability of machines in conducting intelligent tasks • Intelligent Programs – Programs conducting specific intelligent tasks • Artificial Intelligence – Ability of machines in conducting intelligent tasks • Intelligent Programs – Programs conducting specific intelligent tasks Input Intelligent Processing Output
  • 30.
    Example 1: TextClassifier (1) … fiber = 0 … huge = 1 … oil = 1 platforms = 1 … Classification … Crude = 1 … Money-fx = 0 … Ship = 1 … Text File: Huge oil platforms dot the Gulf like beacons -- usually lit up … Preprocessing … fiber = 0 … huge = 1 … oil = 1 platforms = 1 … Classification … Crude = 1 … Money-fx = 0 … Ship = 1 … Text File: Huge oil platforms dot the Gulf like beacons -- usually lit up … Preprocessing
  • 31.
    Example 1: TextClassifier (2) … enter = 1 expected = 1 … federal = 1 … oil = 0 … Classification … Crude = 0 … Money-fx = 1 … Ship = 0 … Text File: The Federal Reserve is expected to enter the government … Preprocessing … enter = 1 expected = 1 … federal = 1 … oil = 0 … Classification … Crude = 0 … Money-fx = 1 … Ship = 0 … Text File: The Federal Reserve is expected to enter the government … Preprocessing
  • 32.
    Example 2: DiseaseClassifier (1) Preprocessed data of patient 1 Age = 67 Sex = 1 Chest pain type = 4 Resting blood pressure = 160 Serum cholestoral = 286 Fasting blood sugar = 0 … Classification Preprocessed data of patient 1 Age = 67 Sex = 1 Chest pain type = 4 Resting blood pressure = 160 Serum cholestoral = 286 Fasting blood sugar = 0 … Classification Presence = 1
  • 33.
    Example 2: DiseaseClassifier (2) Preprocessed data of patient 2 Age = 63 Sex = 1 Chest pain type = 1 Resting blood pressure = 145 Serum cholestoral = 233 Fasting blood sugar = 1 … Classification Preprocessed data of patient 2 Age = 63 Sex = 1 Chest pain type = 1 Resting blood pressure = 145 Serum cholestoral = 233 Fasting blood sugar = 1 … Classification Presence = 0
  • 34.
    Example 3: ChessProgram Searching and evaluating Best move -New matrix Opponent’s playing his move Matrix representing the current board
  • 35.
    AI Approach • Reasoningwith Knowledge – Knowledge base – Reasoning • Traditional Approaches – Handcrafted knowledge base – Complex reasoning process – Disadvantages • Knowledge acquisition bottleneck • Reasoning with Knowledge – Knowledge base – Reasoning • Traditional Approaches – Handcrafted knowledge base – Complex reasoning process – Disadvantages • Knowledge acquisition bottleneck
  • 36.
    Machine Learning • MachineLearning (Mitchell 1997) – Learn from past experiences – Improve the performances of intelligent programs • Definitions (Mitchell 1997) – A computer program is said to learn from experience E with respect to some class of tasks T and performance measure P, if its performance at the tasks improves with the experiences • Machine Learning (Mitchell 1997) – Learn from past experiences – Improve the performances of intelligent programs • Definitions (Mitchell 1997) – A computer program is said to learn from experience E with respect to some class of tasks T and performance measure P, if its performance at the tasks improves with the experiences
  • 37.
    Example 1: TextClassification Classified text files Text file 1 trade Text file 2 ship … … Text classifier New text file class Classified text files Text file 1 trade Text file 2 ship … … Training
  • 38.
    Example 2: DiseaseDiagnosis Database of medical records Patient 1’s data Absence Patient 2’s data Presence … … Disease classifier New patient’s data Presence or absence Database of medical records Patient 1’s data Absence Patient 2’s data Presence … … Training
  • 39.
    Example 3: ChessPlaying Games played: Game 1’s move list Win Game 2’s move list Lose … … Strategy of Searching and Evaluating New matrix representing the current board Best move Games played: Game 1’s move list Win Game 2’s move list Lose … … Training
  • 40.
    Examples • Text Classification –Task T • Assigning texts to a set of predefined categories – Performance measure P • Precision and recall of each category – Training experiences E • A database of texts with their corresponding categories • How about Disease Diagnosis? • How about Chess Playing? • Text Classification – Task T • Assigning texts to a set of predefined categories – Performance measure P • Precision and recall of each category – Training experiences E • A database of texts with their corresponding categories • How about Disease Diagnosis? • How about Chess Playing?
  • 41.
    Why Machine LearningIs Possible? • Mass Storage – More data available • Higher Performance of Computer – Larger memory in handling the data – Greater computational power for calculating and even online learning • Mass Storage – More data available • Higher Performance of Computer – Larger memory in handling the data – Greater computational power for calculating and even online learning
  • 42.
    Advantages • Alleviate KnowledgeAcquisition Bottleneck – Does not require knowledge engineers – Scalable in constructing knowledge base • Adaptive – Adaptive to the changing conditions – Easy in migrating to new domains • Alleviate Knowledge Acquisition Bottleneck – Does not require knowledge engineers – Scalable in constructing knowledge base • Adaptive – Adaptive to the changing conditions – Easy in migrating to new domains
  • 43.
    Success of MachineLearning • Almost All the Learning Algorithms – Text classification (Dumais et al. 1998) – Gene or protein classification optionally with feature engineering (Bhaskar et al. 2006) • Reinforcement Learning – Backgammon (Tesauro 1995) • Learning of Sequence Labeling – Speech recognition (Lee 1989) – Part-of-speech tagging (Church 1988) • Almost All the Learning Algorithms – Text classification (Dumais et al. 1998) – Gene or protein classification optionally with feature engineering (Bhaskar et al. 2006) • Reinforcement Learning – Backgammon (Tesauro 1995) • Learning of Sequence Labeling – Speech recognition (Lee 1989) – Part-of-speech tagging (Church 1988)
  • 44.
  • 45.
    Adaptive Learning Basics •A system which collects user information and behavioral data to customize a learning experience for an individual • Encourages active participation rather than passive receptacle • Moves away from static hypermedia (same page content and links for all users) • Artificial Intelligence movement • A system which collects user information and behavioral data to customize a learning experience for an individual • Encourages active participation rather than passive receptacle • Moves away from static hypermedia (same page content and links for all users) • Artificial Intelligence movement
  • 46.
  • 47.
  • 48.
    Machine Learning • Machinecollects data and recognizes patterns in the data • Algorithms – sequence of instructions to transform the input into output • Intelligent systems have the ability to learn in a changing environment • Machine collects data and recognizes patterns in the data • Algorithms – sequence of instructions to transform the input into output • Intelligent systems have the ability to learn in a changing environment
  • 49.
    Adaptation Process • Datacollection – User interaction – Direct input • Interpret data using models • Infer user requirements and preferences • Tailored aggregation • Presentation of tailored content (adaptive effect) • Synthesis with population data • Data collection – User interaction – Direct input • Interpret data using models • Infer user requirements and preferences • Tailored aggregation • Presentation of tailored content (adaptive effect) • Synthesis with population data
  • 50.
  • 51.
  • 52.
    Categories of Adaptation •Interaction with the system • Course/object delivery • Content adaptation • Collaborative/social support • Interaction with the system • Course/object delivery • Content adaptation • Collaborative/social support
  • 53.
    Content Adaptation • Adaptivepresentation – content of a hypermedia page adapted to the user’s goals, knowledge and other information • Adaptive navigation – link presentation and functionality adapted to the goals, knowledge and characteristics of the user • Direct guidance • Link sorting • Link annotation • Link hiding • Adaptive presentation – content of a hypermedia page adapted to the user’s goals, knowledge and other information • Adaptive navigation – link presentation and functionality adapted to the goals, knowledge and characteristics of the user • Direct guidance • Link sorting • Link annotation • Link hiding
  • 54.
    Assessment • System feedback •Embedded assessment • Adaptive – Timing/architecture – Question level • System feedback • Embedded assessment • Adaptive – Timing/architecture – Question level
  • 55.
    Examples • Adaptive eLearningResearch Group • AHA! • Andes Physics Tutor • ELM-ART • GRE • iKnow! • Learnthat • Khan Academy • Knewton • Adaptive eLearning Research Group • AHA! • Andes Physics Tutor • ELM-ART • GRE • iKnow! • Learnthat • Khan Academy • Knewton
  • 56.
    Adaptive vs machinelearning • An adaptive system is a set of interacting or interdependent entities, real or abstract, forming an integrated whole that together are able to respond to environmental changes or changes in the interacting parts. Feedback loops represent a key feature of adaptive systems, allowing the response to changes; examples of adaptive systems include: natural ecosystems, individual organisms, human communities, human organizations, and human families. • Some artificial systems can be adaptive as well; for instance, robots employ control systems that utilize feedback loops to sense new conditions in their environment and adapt accordingly. • An adaptive system is a set of interacting or interdependent entities, real or abstract, forming an integrated whole that together are able to respond to environmental changes or changes in the interacting parts. Feedback loops represent a key feature of adaptive systems, allowing the response to changes; examples of adaptive systems include: natural ecosystems, individual organisms, human communities, human organizations, and human families. • Some artificial systems can be adaptive as well; for instance, robots employ control systems that utilize feedback loops to sense new conditions in their environment and adapt accordingly.
  • 57.