확률 그래프 모델과 추론 · 2015-11-24 · attach prior probabilities to non-root nodes...
TRANSCRIPT
Byoung-Tak Zhang
Computer Science and Engineering &
Cognitive Science and Brain Science Programs
Seoul National University
Biointelligence Lab & Institute for Cognitive Science
http://bi.snu.ac.kr/
SKT R&D, HMI Tech Lab 2014년 3월 10일(월)
확률 그래프 모델과 추론 Inference with Probabilistic Graphical Models
기계학습이란?
• 학습 시스템: “환경 E와의 상호작용으로부터 획득한 경험적인 데이터 D를 바탕으로 모델 M을 자동으로 구성하여 스스로 성능 P를 향상하는 시스템” – 환경 E
– 데이터 D
– 모델 M
– 성능 P
• 특성 1: Self-improving Systems
(인공지능 관점)
• 특성 2: Knowledge Discovery
(데이터마이닝 관점)
• 특성 3: Data-Driven Software Design
(소프트웨어공학 관점)
• 특성 4: Automatic Programming
(컴퓨터공학 관점)
장병탁, 기계학습 개론, 2014 (to appear)
Traditional Programming
Machine Learning
Computer
Data
Program Output
Computer
Data
Output
Program
Machine Learning as Automatic Programming
2012 (c) SNU
Biointelligence Lab,
http://bi.snu.ac.kr/
Machine Learning (ML): Three Tasks
• Supervised Learning – Estimate an unknown mapping from known input and target output
pairs – Learn fw from training set D = {(x,y)} s.t. – Classification: y is discrete – Regression: y is continuous
• Unsupervised Learning – Only input values are provided – Learn fw from D = {(x)} s.t. – Density estimation and compression – Clustering, dimension reduction
• Sequential (Reinforcement) Learning – Not target, but rewards (critiques) are provided “sequentially” – Learn a heuristic function fw from Dt = {(st,at,rt) | t = 1, 2, …} s.t. – With respect to the future, not just past – Sequential decision-making – Action selection and policy learning
)()( xxw fyf
xxw )(f
( , , )t t tf a rw s
Zhang, B.-T., Next-Generation Machine Learning Technologies, Communications of KIISE, 25(3), 2007 4
기계학습 모델
감독 학습 모델 Neural Nets
Decision Trees
K-Nearest Neighbors
Support Vector Machines
무감독 학습 모델 Self-Organizing Maps
Clustering Algorithms
Manifold Learning
Evolutionary Learning
확률그래프 모델 Bayesian Networks
Markov Networks
Hidden Markov Models
Hypernetworks
동적시스템 모델 Kalman Filters
Sequential Monte Carlo
Particle Filters
Reinforcement Learning
(c) 2009-2010 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
5 장병탁, 기계학습 개론, 2014 (to appear)
Outline
• Bayesian Inference
– Monte Carlo
– Importance Sampling
– MCMC
• Probabilistic Graphical Models
– Bayesian Networks
– Markov Random Fields
• Hypernetworks
– Architecture and Algorithms
– Application Examples
• Discussion
Bayes Theorem
(c) 2010-2012 SNU Biointelligence Laboratory,
http://bi.snu.ac.kr/ 7
MAP vs. ML
• What is the most probable hypothesis given data? – From Bayes Theorem
• MAP (Maximum A Posteriori) –
• ML (Maximum Likelihood) –
(c) 2010-2012 SNU Biointelligence Laboratory,
http://bi.snu.ac.kr/ 8
(c) 2008 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/ 9
(c) 2005 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/ 10
Prof. Schrater’s Lecture Notes
(Univ. of Minnesota)
(c) 2005 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/ 11
(c) 2005 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/ 12
(c) 2005 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/ 13
(c) 2005 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/ 14
Graphical Models
Graphical Models (GM)
Causal Models Chain Graphs Other Semantics
Directed GMs Dependency Networks Undirected GMs
Bayesian Networks
DBNs FST
HMMs
Factorial HMM Mixed Memory Markov Models
BMMs
Kalman
Segment Models
Mixture Models
Decision Trees Simple
Models
PCA
LDA
Markov Random Fields / Markov
networks
Gibbs/Boltzman Distributions
Bayesian Networks
Recommendation Systems
Your friends
attended this
lecture already
and liked it.
Therefore, we
would like to
recommend it
to you !
© 2007, SNU Biointelligence Lab, http://bi.snu.ac.kr/
18
Bayesian Networks
Bayesian network DAG (Directed Acyclic Graph)
Express dependence relations between variables
Can use prior knowledge on the data (parameters)
A B C
P(A,B,C,D,E) = P(A)P(B|A)P(C|B)
P(D|A,B)P(E|B,C,D)
D E
n
i
iiXPP1
)|()( paX
Representing Probability Distributions
• Probability distribution = probability for each
combination of values of these attributes
• Naïve representations (such as tables) run into troubles
– 20 attributes require more than 220106 parameters
– Real applications usually involve hundreds of attributes
Hospital patients described by
• Background: age, gender, history of diseases, …
• Symptoms: fever, blood pressure, headache, …
• Diseases: pneumonia, heart attack, …
Bayesian Networks - Key Idea
• Bayesian networks
• utilize conditional independence
• Graphical representation of conditional
independence respectively “causal”
dependencies
Exploit regularities !!!
Bayesian Networks
1. Finite, directed acyclic graph
2. Nodes: (discrete) random variables
3. Edges: direct influences
4. Associated with each node: a table
representing a conditional probability
distribution (CPD), quantifying the effect the
parents have on the node
M J
E B
A
Bayesian Networks
X1 X2
X3
(0.2, 0.8) (0.6, 0.4)
true 1 (0.2,0.8)
true 2 (0.5,0.5)
false 1 (0.23,0.77)
false 2 (0.53,0.47)
- In
tro
ductio
n
Example
Train
Strike
Martin
Late
Norman
Late
Project
Delay
Office
Dirty
Boss
Angry
Boss
Failure-in-Love
Martin
Oversleep
Norman
Oversleep
Use a DAG to model the causality.
Example
Train
Strike
Martin
Late
Norman
Late
Project
Delay
Office
Dirty
Boss
Angry
Boss
Failure-in-Love
Martin
Oversleep
Norman
Oversleep
Attach prior probabilities to all root nodes
Norman oversleep
Probability
T 0.2
F 0.8
Train Strike
Probability
T 0.1
F 0.9
Martin oversleep
Probability
T 0.01
F 0.99
Boss failure-in-love
Probability
T 0.01
F 0.99
Example
Train
Strike
Martin
Late
Norman
Late
Project
Delay
Office
Dirty
Boss
Angry
Boss
Failure-in-Love
Martin
Oversleep
Norman
Oversleep
Attach prior probabilities to non-root nodes
Norman
untidy
Norman oversleep
T F
Norman
untidy
T 0.6 0.2
F 0.4 0.8
Train strike
T F
Martin oversleep
T F T F
Martin
Late
T 0.95 0.8 0.7 0.05
F 0.05 0.2 0.3 0.95
Each column is summed to 1.
Example
Train
Strike
Martin
Late
Norman
Late
Project
Delay
Office
Dirty
Boss
Angry
Boss
Failure-in-Love
Martin
Oversleep
Norman
Oversleep
Norman
untidy
Each column is summed to 1. Boss Failure-in-love
T F
Project Delay
T F T F
Office Dirty
T F T F T F T F
Boss
Angry
very 0.98 0.85 0.6 0.5 0.3 0.2 0 0.01
mid 0.02 0.15 0.3 0.25 0.5 0.5 0.2 0.02
little 0 0 0.1 0.25 0.2 0.3 0.7 0.07
no 0 0 0 0 0 0 0.1 0.9
Attach prior probabilities to non-root nodes
Inference
A Bayesian Network
The “ICU alarm” network
37 binary random variables
509 parameters instead of
PCWP CO
HRBP
HREKG HRSAT
ERRCAUTER HR HISTORY
CATECHOL
SAO2 EXPCO2
ARTCO2
VENTALV
VENTLUNG VENITUBE
DISCONNECT
MINVOLSET
VENTMACH KINKEDTUBE INTUBATION PULMEMBOLUS
PAP SHUNT
ANAPHYLAXIS
MINOVL
PVSAT
FIO2
PRESS
INSUFFANESTH TPR
LVFAILURE
ERRBLOWOUTPUT STROEVOLUME LVEDVOLUME
HYPOVOLEMIA
CVP
BP
Cf. Markov Networks
Undirected graphs
Nodes = random variables
Cliques = potentials (~ local jpd)
Fielded Applications
• Expert systems
Medical diagnosis (Mammography)
Fault diagnosis (jet-engines, Windows 98)
• Monitoring
Space shuttle engines (Vista project)
Freeway traffic, Activity Recognition
• Sequence analysis and classification
Speech recognition (Translation, Paraphrasing
Biological sequences (DNA, Proteins, RNA, ..)
• Information access
Collaborative filtering
Information retrieval & extraction
… among others ?
© 2007, SNU Biointelligence Lab, http://bi.snu.ac.kr/
32
Web Mining: e-Commerce
© 2007, SNU Biointelligence Lab, http://bi.snu.ac.kr/
33
KDD-2000 Web Mining Competition
Data: 465 features over 1700 customers
Features include friend promotion rate, date
visited, weight of items, price of house,
discount rate, …
Data was collected during Jan. 30 – March
30, 2000
Friend promotion was started from Feb. 29
with TV advertisement.
Aims: Description of heavy/low spenders
Web Mining: Customer Analysis
© 2007, SNU Biointelligence Lab, http://bi.snu.ac.kr/
34
Web Mining: Customer Analysis
© 2007, SNU Biointelligence Lab, http://bi.snu.ac.kr/
35
© 2007, SNU Biointelligence Lab, http://bi.snu.ac.kr/
36
Web Mining: Results
A Bayesian net for
KDD web data
V229 (Order-Average) and
V240 (Friend) directly
influence V312 (Target)
V19 (Date) was influenced by
V240 (Friend) reflecting the
TV advertisement.
[Chang et al., 2002]
Markov Random Fields
(Markov Networks)
Graphical Models
38
Directed Graph (e.g. Bayesian Network)
Undirected Graph (e.g. Markov Random Field)
(c) 2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
Bayesian Image Analysis
Likelihood Marginal
yProbabilit PrioriA Processn Degradatio
yProbabilit PosterioriA Image Degraded
Image OriginalImage OriginalImage DegradedImage DegradedImage Original
Pr
PrPr Pr
Original Image Degraded
(observed) Image
Transmission
Noise
Image Analysis
We could thus represent both the observed image (X) and
the true image (Y) as Markov random fields.
And invoke the Bayesian framework to find P(Y|X)
X – observed image
Y – true image
Details
Remember
P(Y|X) proportional to P(X|Y)P(Y)
P(X|Y) is the data model.
P(Y) models the label interaction.
Next we need to compute the prior P(Y=y)
and the likelihood P(X|Y).
P(Y | X) =P(X |Y )P(Y )
P(X)µP(X |Y )P(Y )
Back to Image Analysis
Likelihood can be modeled as a mixture of
Gaussians.
The potential is modeled to capture the domain
knowledge. One common model is the Ising
model of the form βyiyj
Bayesian Image Analysis
Let X be the observed image = {x1,x2…xmn}
Let Y be the true image = {y1,y2…ymn}
Goal : find Y = y* = {y1*,y2*…} such that P(Y = y*|X)
is maximum.
Labeling problem with a search space of Lmn
L is the set of labels.
m*n observations.
Unfortunately
Observed Image SVM MRF
Markov Random Fields (MRFs)
Introduced in the 1960s, a principled approach for
incorporating context information.
Incorporating domain knowledge .
Works within the Bayesian framework.
Widely worked on in the 70s, disappeared over the 80s,
and finally made a big come back in the late 90s.
Markov Random Field
Random Field: Let be a family of
random variables defined on the set S , in which each
random variable takes a value in a label set L. The
family F is called a random field.
Markov Random Field: F is said to be a Markov random
field on S with respect to a neighborhood system N if and
only if the following two conditions are satisfied:
},...,,{ 21 MFFFF
iF if
Positivity: ( ) 0,P f f F
)|(}){|( :tyMarkovianiiNii ffPiSfP
Inference
Finding the optimal y* such that P(Y=y*|X) is maximum.
Search space is exponential.
Exponential algorithm - simulated annealing (SA)
Greedy algorithm – iterated conditional modes (ICM)
There are other more advanced graph cut based
strategies.
Sampling and Simulated Annealing
Sampling
A way to generate random samples from a (potentially very
complicated) probability distribution.
Gibbs/Metropolis.
Simulated annealing
A schedule for modifying the probability distribution so that, at
“zero temperature”, you draw samples only from the MAP
solution.
If you can find the right cooling schedule the algorithm
will converge to a global MAP solution.
Flip side --- SLOW finding the correct schedule is non
trivial.
Iterated Conditional Modes
Greedy strategy, fast convergence
Idea is to maximize the local conditional probabilities
iteratively, given an initial solution.
Simulated annealing with T =0 .
Parameter Learning
Supervised learning (easiest case)
Maximum likelihood:
For an MRF:
( | )/1( | )
( )
U f TP f eZ
* arg max ( | )P f
Pseudo Likelihood
So we approximate
Large lattice theorem: in the large lattice limit M, PL
converges to ML estimate.
Turns out that a local learning method like pseudo-likelihood
when combined with a local inference method such as ICM
does quite well. Close to optimal results.
( , )
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i i Ni
i j j N j
j
U f f
i N U f fi X
f L
ePL f P f f
e
( ) ( , )ii i N
i
U f U f f
Hypernetworks
Graphical Models
53
Directed Graph (e.g. Bayesian Network)
Undirected Graph (e.g. Markov Random Field)
(c) 2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
© 2010, SNU Biointelligence Lab, http://bi.snu.ac.kr/ 54
From Simple Graphs to Higher-Order Graphs
G
F
J
A
S
G
F
J
A
S
{ , , , }
( | , , , )
( , , , | ) ( )
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P F J G S A
P J G S A F P F
P J G S A
P J G S A F
P J F P G F P S F P A F
P x F
G
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{ , , , , }
( , , , , )
( | ) ( | ) ( | )( | )
( | ( ))x F J G S A
P F J G S A
P G F P J F P J A J S
P x pa x
( , ) {( , )| , { , , , } and }
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x y
P F J G S A
P J G F P J S F P J A F
P G S F P G A F
P S A F
P he x y F
(1) Naïve Bayes
(2) Bayesian Net
(3) High-Order PGM
x1
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[Zhang, DNA-2006]
[Zhang, IEEE CIM, 2008]
Hypernetwork as a Probabilistic Distributed Associative Memory
Hyperedges
55 (c) 2010-2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
56
Hypernetwork Coding: Population of
Hyperedges
v5
v1
v3
v7
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H = (V, E, W)
V = {v1, v2, v3, …, v7}
E = {E1, E2, E3, E4, E5}
W = {w1, w2, w3, w4, w5}
E1 = {v1, v3, v4} E2 = {v1, v4}
E3 = {v2, v3, v6}
E4 = {v3, v4, v6, v7}
E5 = {v4, v5, v7}
E1
E4
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E2
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(c) 2005-2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
[Zhang, 2008]
© 2010, SNU Biointelligence Lab, http://bi.snu.ac.kr/
57 x8 x9
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Round 1 Round 2 Round 3
Data
x8 x11 y=0 x6
x11 x15 y=0 x8
(c) 2005-2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
57
© 2009, SNU Biointelligence Lab, http://bi.snu.ac.kr/
58
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[Zhang, DNA-2006]
[Zhang, IEEE CIM, 2008]
Hypernetwork as a Probabilistic Model of Distributed Parallel Associative Memory
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59 (c) 2010-2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
Derivation of the Learning Rule
(c) 2010-2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/ 60
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Higher-order terms Explicit representation
fast learning
cf. Bayesian networks
Structural learning
Evolving complex networks
discovery of modules
cf. Markov random fields
Population coding
Collection of modules
incremental learning
cf. numerical CPT
Features of Hypernetworks
Compositionality Creation of new modules
symbolic computation
cf. connectionist models
Self-supervised
Can learn from unlabeled data
no need for labeling
cf. supervised
Reconfigurable architecture
Run-time self-assembly
anytime inference
cf. fixed architecture
61 (c) 2010-2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
Difference from Markov Networks
In Markov networks, the joint distribution is written as a product of
potential functions over the maximal cliques of the graph
Similarity
Hyperedges define potential functions (components) like cliques
Distribution is represented as a product of potential functions
Difference
Novel hyperedges are constructed from data (cliques are given)
Both model structures and parameters are evolved (cliques are fixed)
Hyperedges can be ordered (cliques are not)
1( ) ( )C C
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energy function
Boltzmann
Distribution
62 (c) 2010-2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
Mobile Phone Applications of Hypernetworks
• mLife
• eHealth
Mobile Sensors on Smartphones
일상 Logging을 통한 사용자의 행동패턴 인식 및 추천
Android 스마트폰을 이용하여 Real-life logging data 를 수집 (삼성
Galaxy S 시리즈, HTC Desire)
64 Action Logger (MDS)
센서 정보
GPS 절대 위치 정보
Accelerometer 3D 축을 기준으로 가속도 크기 및 방향
Proximity 단말 가까이에 물체의 존재 유무
Orientation 단말 정면을 기준으로 roll과 pitch 값
Magnetic fields 자기장 센서
Illuminometer 조도센서
Sound Noise Noise sound의 크기
Bluetooth Bluetooth device address
WIFI SSID 명, 신호 세기
(c) 2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
Mobile Sensor Data
(c) 2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
추론 예: 일반적인 경우 학습모델을 이용한 추론의 예
User Scenario
DietAdvisor: A Personalized eHealth Agent in a Mobile Computing Environment 67
John’s daily-life and
DietAdvisor
Experimental Results: Activity Recognition
DietAdvisor: A Personalized eHealth Agent in a Mobile Computing Environment 68
Personalized Recommendation Module
Hypernetwork-based learning for menu
DietAdvisor: A Personalized eHealth Agent in a Mobile Computing Environment 69
Weight Item1 Item2
15 쌀밥 배추김치
3 김 깍두기
2 현미밥 버섯볶음
4 계란찜 숙주나물
4 쌀밥 두부조림
1 배추김치 깍두기
3 부추김치 장조림
5 마른김 양념간장
6 현미밥 배추김치
3 탕수육 군만두
4 현미밥 북어국
0 X X
Weight Item1 Item2
15 쌀밥 배추김치
3 김 깍두기
3 현미밥 버섯볶음
4 계란찜 숙주나물
4 쌀밥 두부조림
1 배추김치 깍두기
3 부추김치 장조림
5 마른김 양념간장
7 현미밥 배추김치
3 탕수육 군만두
4 현미밥 북어국
1 북어국 버섯볶음
Learning Late: 50%
Experimental Results: Menu Recommendation
DietAdvisor: A Personalized eHealth Agent in a Mobile Computing Environment 70
Other Applications of
Hypernetworks
• Language, Music, and Videos
• CogTV Recommendations
© 2010, SNU Biointelligence Lab, http://bi.snu.ac.kr/
72
Text Corpus: TV Drama Series
Friends, 24, House, Grey Anatomy, Gilmore Girls, Sex and the City
289,468
Sentences
(Training Data)
700 Sentences
with Blanks
(Test Data)
I don't know what happened.
Take a look at this. …
What ? ? ? here. ? have ? visit the ? room.
…
73
Sentence Completion Task
Why ? you ? come ? down ?
Why are you go come on down here
? appreciate it if ? call her by ? ?
I appreciate it if you call her by the way
Would you ? to meet ? ? Tuesday ?
Would you nice to meet you in Tuesday and
? gonna ? upstairs ? ? a shower
I'm gonna go upstairs and take a shower
? have ? visit the ? room I have to visit the ladies' room
? ? ? decision
to make a decision
? still ? believe ? did this
I still can't believe you did this
(c) 2005-2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
74
Corpus: Friends
Keyword: “mother”
Corpus: Prison Break
Keyword: “mother” you're mother killed herself it's my mother was shot by a woman at eight we're just gonna go to your mother that i love it feeling that something's wrong with my mother and father she's the single mother i put this on my friend's mother apparently phoebe's mother killed herself thanks for pleasing my mother killed herself i'm your mother told you this is an incredible mother that's not his mother or his hunger strike holy mother of god woman i like your mother and father on their honeymoon suite with her and never called your mother really did like us is my mother was shot by a drug dealer
tells his mother and his family she's the mother of my eyes speak to your mother used to be tells his mother made it pretty clear on the floor has speak to your mother never had life insurance she's the mother of lincoln's child she's the mother of my own crap to deal with you just lost his mother is fine just lost his mother and his god tells his mother and his stepfather she's the mother of my time his mother made it clear you couldn't deliver fibonacci she's the mother of my brother is facing the electric chair same guy who was it your mother before you do it they gunned my mother down
Concept Maps for Friends and Prison Break
[J.-H. Lee et al., 2009]
Music Generation Result: Cross-Corpus
Scores generated by Evolutionary Hypernetworks that learned
American (A), Scottish (B), Korean Singer Kim (C), and Korean
Singer Shin (D) with the cue (left side of the bar in the middle)
from “Swanee River”, the famous American folk song
[H.-W. Kim and B.-H. Kim]
(c) 2005-2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
75
Digital Videos for Teaching Machines
(c) 2010-2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/
76
Multimodal Language
Vision
Audio
“Situated”
Contexts
“Naturalistic”
Dynamic
“Quasireal”
Continuous
Educational
LEARNING BY PLAYING
Learning the image from the given text
Click the Right Option
Text Query
Score : 01
78
Learning the text from the given image
LEARNING BY PLAYING
Image Query
Click the Right Option
Score : 02
© 2010, SNU Biointelligence Lab, http://bi.snu.ac.kr/
0.5
0.55
0.6
0.65
0.7
0.75
0.8
0.85
0.9
0.95
1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Player 1
Player 2
No. of Sessions
Acc
ura
cy
Result 1: Humans for T2I Learning
Result 2: Humans for I2T Learning
© 2010, SNU Biointelligence Lab, http://bi.snu.ac.kr/
No. of Sessions
Acc
ura
cy
0.5
0.55
0.6
0.65
0.7
0.75
0.8
0.85
0.9
0.95
1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Player 1
Player 2
© 2010, SNU Biointelligence Lab, http://bi.snu.ac.kr/
0.4
0.45
0.5
0.55
0.6
0.65
0.7
0.75
0.8
0.85
0.9
0.95
1
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105
No. of Epochs
Acc
ura
cy
Result 3: Machines for I2T Learning
[Fareed et al., 2009]
Answer Query
I don't know what
happened
There's a kitty in my
guitar case
Maybe there's
something I can do to
make sure I get
pregnant
Maybe there's something
there's something I
…
I get pregnant
There's a
a kitty in
…
in my guitar case
I don't know
don't know what
know what happened
Matching &
Completion
Image-to-Text Recall Examples
© 2009, SNU Biointelligence Lab, http://bi.snu.ac.kr/
Query Matching &
Completion
I don't know what happened
Take a look at this
There's a kitty in my guitar case
Maybe there's something I
can do to make sure I get
pregnant
Answer
Text-to-Image Recall Examples
© 2009, SNU Biointelligence Lab, http://bi.snu.ac.kr/
Utterance-scene representation
84
Word Learning from Video
Oh, the rabbit's followed you
home, Maisy.
Oh, and don't forget panda.
Good night, bird. See you
in the morning.
Original sentence-scene pairs
rabbit, followed,
home, maisy
forget, panda
good, night, bird,
see, morning
Visual words Textual words
Concept representation
85
Sparse Population Code Models
w
w
w
w
w
v
v
v
v
mouse
tail
yellow
dark
v
longwred
w
eye
v
v
v
v
w ear
v
whop
w
run
Concept map for MOUSE Concept map for RABBIT
[Zhang et al., CogSci-2012]
Concept generalization and specialization (cont’d)
86
Experimental Results
bird
rabbit little
favoriteonion
excited
today
doingfarm
water
idea
night
morning
hole
rabbit
ride
maisy
good
want
need
look
helping
new
tree
diggingpenguin
Episodes 1-4 Episodes 1-6
[Zhang et al., CogSci-2012]
CogTV: 멀티모달 인터랙티브 추천서비스 플랫폼
87
User Log 환경 데이터
User Descriptor
사용자 데이터
Image/Audio/Text
데이터 학습/추론엔진
멀티모달 스트림데이터
데이터
인지기반 추론엔진
추천 서비스 데이터
User Interface
사용자 학습 및 모델링 엔진
인지기반 연상검색
내용기반추천
User
Cognitive TV
88
• 인터랙티브 홈씨어터 파일럿 버전 구축 (가상 거실 환경 조성 및 디지털 컨텐츠 수집)
• 인터랙티브 홈씨어터 환경에서 시청자의 인지 모형 구축을 위한 실험 설계, 수행 및 데이터 수집
MMG + EEG Experiments
Projection System: TRI-SPACE, an immersive VR-display system providing 3
stereoscopic screens using 6 digital JVC D-ILA projectors by 3Dims
Eye tracker: ViewPoint PC-60, BS007, from Arrington Research
Head movement tracking: An optical (cable-less) tracking system by ART
Visualization Software: InstantReality, OpenSG
MMG + Eye-Tracking Experiments
In Collaboration with Bielefeld University, Germany
Acknowledgements
Sponsors: National Research Foundation (NRF), Ministry of Education, Science, and
Technology (MEST), Ministry of Knowledge Economy (MKE), Samsung Electronics, and
Microsoft Research (MSR)
(c) 2005-2012 SNU Biointelligence Laboratory, http://bi.snu.ac.kr/ 91