Declarative Data Science Machines Sriraam Amir Martin Babak - - PowerPoint PPT Presentation

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Declarative Data Science Machines Sriraam Amir Martin Babak - - PowerPoint PPT Presentation

Declarative Data Science Machines Sriraam Amir Martin Babak Natarajan Globerson Mladenov Ahmadi and many U. Indiana HUJI TUD, Google PicoEgo more Kristian Martin Pavel Christopher Christian Grohe Tokmakov Re Kersting


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SLIDE 1

Declarative Data Science Machines

Kristian Kersting

Martin Mladenov TUD, Google Babak Ahmadi PicoEgo Amir Globerson HUJI Martin Grohe RWTH Aachen Sriraam Natarajan

  • U. Indiana

and many more …

Pavel Tokmakov INRIA Grenoble Christopher Re Stanford Christian Bauckhage

  • U. Bonn
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SLIDE 2

What about “-O” flags for Data Science Machines

Kristian Kersting

Martin Mladenov TUD, Google Babak Ahmadi PicoEgo Amir Globerson HUJI Martin Grohe RWTH Aachen Sriraam Natarajan

  • U. Indiana

and many more …

Pavel Tokmakov INRIA Grenoble Christopher Re Stanford Christian Bauckhage

  • U. Bonn
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SLIDE 3

Kristian Kersting - Declarative Data Science Machines

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SLIDE 4

Arms race to “deeply” understand data

Kristian Kersting - Declarative Data Science Machines

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SLIDE 5

Kristian Kersting - Declarative Data Science Machines

Take your spreadsheet …

Features Objects

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Latent Dirichlet Allocation Big Data Matrix Factorization

Kristian Kersting - Declarative Data Science Machines

Features Objects

… and apply Machine Learning

Gaussian Processes Decision Trees/Boosting Autoencoder/Deep Learning

and many more …

t

F(t) f(t)

Diffusion Models Distillation/LUPI

Big

Model

Small

Model

teaches

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SLIDE 7

Kristian Kersting - Declarative Data Science Machines

IS IT REALLY THAT SIMPLE?

Plant Phenotyping

Not only Big on data but also on interpretability

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SLIDE 8

What is the biological meaning of an eigenvector?

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SLIDE 9

Simplex Volume Maximization

[Thurau, Kersting, Bauckhage, DAMI 2012]

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SLIDE 10

Simplex Volume Maximization

[Römer et al. Functional Plant Biology 2012, Wahabzada et al. PlosOne 2015, Wahabzada et

  • al. Scientific Reports (Nature) 2016; Leuker et al. Functional Plant Biology 2016]

Mainly pigments

[Thurau, Kersting, Bauckhage, DAMI 2012]

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SLIDE 11

Kristian Kersting - Declarative Data Science Machines

IS IT REALLY THAT SIMPLE?

Several statistics used to characterize graphs: Degree distribution, average path length, diameter, cluster coefficients, ...

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Kristian Kersting - Declarative Data Science Machines

MY IT‘S A (SMALL) WORLD

  • S. Milgram

Psychology Today 2:60-67, 1967

  • K. Bacon

The (six-)degree of separation

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SLIDE 13

MY IT‘S A (SMALL) WORLD

The (six-)degree of separation

[Bauckhage, Kersting, Hadiji UAI 2015]

is the mean of a generalized Gamma Distribution

R R R R R R R R R R R R R R I I I I

d = 0 d = 1 d = 2 d = 3

Proof: SIR-model, multinomial over histogram

  • f distance, use Sterling’s formula to turn into

maxent, impose constraints such that polynomial reachability + finite moments

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SLIDE 14

MY IT‘S A (SMALL) WORLD

The (six-)degree of separation

[Bauckhage, Kersting, Hadiji UAI 2015]

is the mean of a generalized Gamma Distribution

1 2 3 4 5 6 7 8 9

path length

0.0 0.2 0.4 0.6 0.8 1.0

frequency

GenGamma data

101 102 103 node degree 10−4 10−3 10−2 10−1 100 frequency

data fit

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SLIDE 15

„The subject of collective attention is central to an information age where millions of people are inundated with daily messages. “

  • Wu and Huberman, PNAS, 104(45), 2007
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Kristian Kersting - Declarative Data Science Machines

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SLIDE 17

Kristian Kersting - Declarative Data Science Machines

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SLIDE 18

Kristian Kersting - Declarative Data Science Machines

Can YouTube videos really go viral?

Bauckhage, Kersting, Hadiji ICWSM 2015

S I R

i r 1 − i 1 − r 1

f(t) = 8 < :

α α−λ e−λt + λ λ−α ↵ e−αt

if 6= ↵ 2 t e−λt if = ↵. Closed-from density of two convolved exponential distributions

Yes, they are ! Collective attention to YouTube videos follows an epidemic model

YoutTube View Counts Google Trend Search Counts

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SLIDE 19

Unsettledness in Politics and Business

Let’s better not say anything. Otherwise, we will have an

  • nline firestorm

tomorrow

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Kristian Kersting - Declarative Data Science Machines reuters.com/article/2011/11/22/us-qantas-idUSTRE7AL0HB20111122

Just a day after Qantas and its unions broke off contract negotiations and after Qantas grounded its fleet in late October, Qantas invited users to enter a "Qantas Luxury" competition, asking people to describe their "dream luxury in-flight experience”

10 20 30 40 50 20 40 60 80 100

Hours after outbreak Attention

qantasluxury

  • SIR

SIR/C CF1−3 CF1−4

  • Tweets/1h

Tweets/8h

Kersting, Bauckhage, Köcher, Swazinna, Pfeffer 2016

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SLIDE 21

Kristian Kersting - Declarative Data Science Machines

IS IT REALLY THAT SIMPLE?

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SLIDE 22

E.g. mining Electronic Health Records are an opportunities to save our lifes and a lot of money.

PatientID Date Prescribed Date Filled Physician Medication Dose Duration P1 5/17/98 5/18/98 Jones prilosec 10mg 3 months PatientID SNP1 SNP2 … SNP500K P1 AA AB BB P2 AB BB AA PatientID Gender Birthdate P1 M 3/22/63 PatientID Date Physician Symptoms Diagnosis P1 1/1/01 Smith palpitations hypoglycemic P1 2/1/03 Jones fever, aches influenza PatientID Date Lab Test Result P1 1/1/01 blood glucose 42 P1 1/9/01 blood glucose ??

Patient Table Visit Table Lab Tests SNP Table Prescriptions

Actually, most data in the world are stored in relational DBs

Unfortunately, they are dirty and interconnected

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SLIDE 23

[Circulation; 92(8), 2157-62, 1995; JACC; 43, 842-7, 2004]

Plaque in the left coronary artery

Atherosclerosis is the cause of the majority of Acute Myocardial Infarctions (heart attacks)

Relational Mining of EHRs

Kristian Kersting - Declarative Data Science Machines [Kersting, Driessens ICML´08; Karwath, Kersting, Landwehr ICDM´08; Natarajan, Joshi, Tadepelli, Kersting,

  • Shavlik. IJCAI´11; Khot, Natarajan, Kersting, Shavlik ICDM´13, MLJ´12, Springer Brief´15, MLJ´15]

Algo Likelihood AUC-ROC AUC-PR Time Boosting 0.810 0.961 0.930 9s MLN 0.730 0.535 0.621 93 hrs Probabilities Logical Variables (Placeholders) Probabilistic Rule

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Kristian Kersting - Declarative Data Science Machines [Lu, Krishna, Bernstein, Fei-Fei „Visual Relationship Detection“ CVPR 2016]

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… the study and design of intelligent agents that act in noisy worlds composed of

  • bjects and relations among

the objects

Statistical Relational Learning/AI Mining Probabilistic DBs

Search IR

DM/ML CV KR Optimization CogSci Scaling Uncertainty Logic Graphs Trees Mining And Learning

[Getoor, Taskar MIT Press ’07; De Raedt, Frasconi, Kersting, Muggleton, LNCS’08; Domingos, Lowd Morgan Claypool ’09; Natarajan, Kersting, Khot, Shavlik Springer Brief’15; Russell CACM 58(7): 88-97 ’15]

De Raedt, Kersting, Natarajan, Poole, Statistical Relational Artificial Intelligence: Logic, Probability, and Computation. Morgan and Claypool Publishers, 2016.

Lake, Salakhutdinov, Tenenbaum, Science 350 (6266), 1332-1338, 2015 Tenenbaum, Kemp, Griffiths, Goodman, Science 331 (6022), 1279-1285, 2011

And this had major impact on CogSci

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SLIDE 26

Kristian Kersting - Declarative Data Science Machines

Symbolic-Numerical Inference Feature Extraction Probabilistic Database

(Un-)Structured Data Sources External Databases

Features and Rules

Features and Rules

Weighted Relational/Graph Database and Declarative Mathematical Program

Representation Learning Model Rules and DomainKnowledge DM and ML Algorithms

Inference Results Feedback p 0.9 0.6

Graph Kernels Diffusion Processes Random Walks Decision Trees Frequent Itemsets SVMs Graphical Models Topic Models Gaussian Processes Autoencoder Matrix and Tensor Factorization Reinforcement Learning …

[Ré, Sadeghian, Shan, Shin, Wang, Wu, Zhang IEEE Data Eng. Bull.’14; Natarajan, Picado, Khot, Kersting, Ré, Shavlik ILP’14; Natarajan, Soni, Wazalwar, Viswanathan, Kersting Solving Large Scale Learning Tasks’16, Mladenov, Heinrich, Kleinhans, Gonsior, Kersting DeLBP’16, …]

Declarative Data Science Machines

The next breakthrough in data analytics may not be a new data analysis algorithm… …but may be in the ability to rapidly combine, deploy, and maintain existing algorithms

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SLIDE 27

BUT WHAT DOES “RAPIDLY COMBINE AND DEPLOY” MEAN?

Kristian Kersting - Declarative Data Science Machines

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SLIDE 28

Guy van den Broeck UCLA

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SLIDE 29

card (1,d2) card (1,d3) card (1,pAce) card (52,d2) card (52,d3) card

(52,pAce)

… … … …

Guy van den Broeck UCLA

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SLIDE 30

card (1,d2) card (1,d3) card (1,pAce) card (52,d2) card (52,d3) card

(52,pAce)

… … … …

Guy van den Broeck UCLA

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SLIDE 31

No independencies. Fully connected. 22704 states

card (1,d2) card (1,d3) card (1,pAce) card (52,d2) card (52,d3) card

(52,pAce)

… … … …

Guy van den Broeck UCLA

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SLIDE 32

A machine will not solve the problem

card (1,d2) card (1,d3) card (1,pAce) card (52,d2) card (52,d3) card

(52,pAce)

… … … …

Guy van den Broeck UCLA

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Faster modelling Faster inference and learning

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WHAT ARE SYMMETRIES IN APPROXIMATE PROBABILISTIC INFERENCE?

Kristian Kersting - Declarative Data Science Machines

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Lifted Loopy Belief Propagation = Exploit computational symmetries

Compress the model Run a modified Loopy Belief Propagation

[Singla, Domingos AAAI’08; Kersting, Ahmadi, Natarajan UAI’09; Ahmadi, Kersting, Mladenov, Natarajan MLJ’13]

Kristian Kersting - Declarative Data Science Machines

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SLIDE 37

Compression: Coloring the graph

§ Color nodes according to the evidence you have

§ No evidence, say red § State „one“, say brown § State „two“, say orange § ...

§ Color factors distinctively according to their equivalences For instance, assuming f1 and f2 to be identical and B appears at the second position within both, say blue

[Singla, Domingos AAAI’08; Kersting, Ahmadi, Natarajan UAI’09; Ahmadi, Kersting, Mladenov, Natarajan MLJ’13]

Kristian Kersting - Declarative Data Science Machines

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SLIDE 38

Compression: Pass the colors around

  • 1. Each factor collects the colors of its neighboring nodes

Kristian Kersting - Declarative Data Science Machines

[Singla, Domingos AAAI’08; Kersting, Ahmadi, Natarajan UAI’09; Ahmadi, Kersting, Mladenov, Natarajan MLJ’13]

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SLIDE 39

Compression: Pass the colors around

  • 1. Each factor collects the colors of its neighboring nodes
  • 2. Each factor „signs“ ist color signature with its own color

Kristian Kersting - Declarative Data Science Machines

[Singla, Domingos AAAI’08; Kersting, Ahmadi, Natarajan UAI’09; Ahmadi, Kersting, Mladenov, Natarajan MLJ’13]

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SLIDE 40

Compression: Pass the colors around

  • 1. Each factor collects the colors of its neighboring nodes
  • 2. Each factor „signs“ ist color signature with its own color
  • 3. Each node collects the signatures of its neighboring factors

Kristian Kersting - Declarative Data Science Machines

[Singla, Domingos AAAI’08; Kersting, Ahmadi, Natarajan UAI’09; Ahmadi, Kersting, Mladenov, Natarajan MLJ’13]

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SLIDE 41

Compression: Pass the colors around

  • 1. Each factor collects the colors of its neighboring nodes
  • 2. Each factor „signs“ ist color signature with its own color
  • 3. Each node collects the signatures of its neighboring factors
  • 4. Nodes are recolored according to the collected signatures

Kristian Kersting - Declarative Data Science Machines

[Singla, Domingos AAAI’08; Kersting, Ahmadi, Natarajan UAI’09; Ahmadi, Kersting, Mladenov, Natarajan MLJ’13]

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SLIDE 42

Compression: Pass the colors around

  • 1. Each factor collects the colors of its neighboring nodes
  • 2. Each factor „signs“ ist color signature with its own color
  • 3. Each node collects the signatures of its neighboring factors
  • 4. Nodes are recolored according to the collected signatures
  • 5. If no new color is created stop, otherwise go back to 1

Kristian Kersting - Declarative Data Science Machines

[Singla, Domingos AAAI’08; Kersting, Ahmadi, Natarajan UAI’09; Ahmadi, Kersting, Mladenov, Natarajan MLJ’13]

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This compression can speed up considerably loopy BP and also training graphical models

[Singla, Domingos AAAI’08; Kersting, Ahmadi, Natarajan UAI’09; Ahmadi, Kersting, Mladenov, Natarajan MLJ’13; Van Haaren, Van den Broeck, Meert, Davis MLJ‘16]

CORA entity resolution parameter training using a lifted stochastic gradient

Kristian Kersting - Declarative Data Science Machines

can be orders of magnitude faster than state-of-the-art

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SLIDE 44

The Weisfeiler-Lehman Algorithm

It turns out that color passing is well known in graph theory

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Weisfeiler-Lehman (WL) Algorithmus aka “naive vertex classification”

§ Basic subroutine for graph isomorphism testing § Computes LP-relaxations of GA-ILP,

  • aka. fractional automorphisms

§ Quasi-linear running time O((n+m)log(n)) when using asynchronous updates [Berkholz, et al. ESA´13] § Part of graph tool SAUCY [See e.g. Darga, Sakallah, Markov DAC´08] § Has lead to highly performant graph kernels [Shervashidze

et al. JMLR 12:2539-2561 ´11, Neumann, Garnett, Bauckhage, Kersting MLJ 102(2):209-245´16]

§ Can be extended to weighted graphs/real-valued matrices [Grohe, Kersting, Mladenov, Selman ESA´14] § Can be viewed as recursive spectral clustering using random walks [Kersting, Mladenov, Garnett, Grohe AAAI´14]

Kristian Kersting - Declarative Data Science Machines

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Kristian Kersting - Declarative Data Science Machines

... and it paves the way to an

algebraic understanding of lifted inference:

Instead of looking at ML through the glasses of probabilities over possible worlds, let‘s approach it using optimization

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SLIDE 47

Approximate inference in graphical models is closely connected to linear programs

Kristian Kersting - Declarative Data Science Machines

Marginal Polytope Relaxed Polytope Objective Function

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Lifted Linear Programming

[Mladenov, Ahmadi, Kersting AISTATS´12, Grohe, Kersting, Mladenov, Selman ESA´14, Kersting, Mladenov, Tokmatov AIJ´15]

Kristian Kersting - Declarative Data Science Machines

(1) Reduce the LP by running WL on the LP-Graph (2) Run any solver on the (hopefully) smaller LP

quasi-linear overhead that may result in exponential speed up

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SLIDE 49

Why does this work?

Feasible region

  • f LP and the
  • bjective vectors

Span of the fractional auto- morpishm of the LP Projections of the feasible region onto the span of the fractional auto- morphism

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SLIDE 50

Lifted approximate inference in graphical models

Kristian Kersting - Declarative Data Science Machines

Marginal Polytope Relaxed Polytope Objective Function Symmetrized Subspace

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SLIDE 51

LBP LCE BP Modified MP Beliefs Pseudo Beliefs MAP-LP Standard Lifted MPLP and Co Concave energies LMPLP

Kristian Kersting - Declarative Data Science Machines

[Mladenov, Globerson, Kersting UAI 2014; Mladnov, Kersting UAI 2015]

requires one to reimplement each algorithm

All message-passing inference approaches based on LPs are liftable

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SLIDE 52

LBP LCE BP Modified MP Beliefs Pseudo Beliefs MAP-LP Standard Lifted MPLP and Co Concave energies LMPLP

Kristian Kersting - Declarative Data Science Machines

[Mladenov, Globerson, Kersting UAI 2014; Mladnov, Kersting UAI 2015]

requires one to reimplement each algorithm

lifting refine

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SLIDE 53

Reparameterized BP ?

Reparameterized

Lifting as preprocessing Run any existing MP solver

RMPLP RCE LBP LCE BP Modified MP Beliefs Pseudo Beliefs MAP-LP Standard Lifted MPLP and Co Concave energies LMPLP

Lifted inference = Inference in a smaller, reparameterized model

Kristian Kersting - Declarative Data Science Machines

[Mladenov, Globerson, Kersting UAI 2014; Mladnov, Kersting UAI 2015]

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MAP Any MAP-LP message-passing approach is liftable

40 50

Domain Size MPLP-reparam. MPLP-ground MPLP-reparam. TRW-reparam.

5 15 25 50 5 10 20 30 40 50 5 10 20 30 40 50

120

[Mladenov, Globerson, Kersting AISTATS `14, UAI `14; Mladenov, Kersting UAI´15]

Kristian Kersting - Declarative Data Science Machines

(a) Complete Graph MLN. (b) Clique-Cycle MLN.

10 5 5 10 W 20000 40000 60000 80000 100000 120000 140000 Objective of dcBP ground reparam 50 100 150 200 250 300 Domain Size 2 4 6 8 10 12 14 |V| + |F|, log 50 100 150 200 250 300 Domain Size 2 1 1 2 3 4 5 Running time, log scale

(c) Friends-smokers MLN.

Marginals Any concave free energy is liftable

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BUT WAIT A MINUTE! WE WANT TO USE ANY DATA SCIENCE METHOD, NOT JUST GRAPHICAL MODELS!

Kristian Kersting - Declarative Data Science Machines

Latent Dirichlet Allocation Matrix Factorization Gaussian Processes Decision Trees/Boosting Autoencoder/Deep Learning

and many more …

Support Vector Machines

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SLIDE 56

Let’s say we want to classify publications that cite each other into scientific disciplines

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SLIDE 57

This is a quadratic program. If you replace l2- by l1-,l∞-norm you get a linear program

H∗ = n ~ x

  • D

~ x , ~

  • E

+ 0 = 0

  • H1

H2

+ + + + + − − − − − − − d(H1, H2)

d(H1, H2) = 2 ||~ ||

Standard data science approach: Support Vector Machines

Kristian Kersting - Declarative Data Science Machines

[Vapnik ´79; Bennett´99; Mangasarian´99; Zhou, Zhang, Jiao´02, ... ]

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SLIDE 58

Relational Mathemtical Programming

[Kersting, Mladenov, Tokmakov AIJ´15, Mladenov, Heinrich, Kleinhans, Gonsio, Kersting DeLBP´16]

Logically parameterized constraint Data stored externally

http://www-ai.cs.uni-dortmund.de/weblab/static/RLP/html/

Logically parameterized variable (set of ground variables)

Write down the problem in „paper form“. The machine compiles into algebraic solver form.

Logically parameterized objective

Kristian Kersting - Declarative Data Science Machines

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SLIDE 59

But wait, publications are citing each other. OMG, I have to use graph kernels!

REALLY?

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SLIDE 60

Kristian Kersting - Declarative Data Science Machines

Simply program some additional constraints

[Kersting, Mladenov, Tokmakov AIJ´15, Mladenov, Heinrich, Kleinhans, Gonsio, Kersting DeLBP´16]

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SLIDE 61

Finally, the „-O1“ flag

[Kersting, Mladenov, Tokmakov AIJ 2015, Mladenov, Kleinhans, Kersting CoRR abs/1606.04486 2016] Kristian Kersting - Declarative Data Science Machines

(1) Reduce the QP via symmetries (2) Run any solver on the reduced QP

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SLIDE 62

Algebraic Decision Diagrams

Formulae parse trees

Matrix Free Optimization

(

è

)

+

Actually, there there are other “-02”, “-03”, … flags ahead, e.g symbolic-numerical interior point solvers

Kristian Kersting - Declarative Data Science Machines

[Mladenov, Belle, Kersting CoRR abs/1605.08187 2016]

Applies to QPs but here illustrated on MDPs for a factory agent which must paint two objects and connect

  • them. The objects must be smoothed, shaped and polished and possibly drilled before painting, each of

which actions require a number of tools which are possibly available. Various painting and connection methods are represented, each having an effect on the quality of the job, and each requiring tools. Rewards (required quality) range from 0 to 10 and a discounting factor of 0. 9 was used used >4.8x faster than state-of-the-art

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SLIDE 63

FRACTIONAL SYMMETRIES ARE …

Conclusions

Kristian Kersting - Declarative Data Science Machines

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SLIDE 64

SYMMETRY-BASED DATA SCIENCE

… a natural foundation for

Kristian Kersting - Declarative Data Science Machines

§ Learning (rich) representations is a central problem of data science § (Fractional) symmetry / group theory is a natural foundation for learning representations § Symmetries = “unimportant” variants of data (graphs, relational structures, …) § Let’s move beyond QPs: CSPs, SDPs, Autoencoders, Deep Learners, …

[Kersting, Kleinhans, Mladenov to be submitted]

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SLIDE 65

DECLARATIVE DATA SCIENCE

Together with high-level data science languages this is a step towards

Kristian Kersting - Declarative Data Science Machines

§ Reduces the level of expertise necessary to build data science applications, makes models faster to write and easier to communicate § Facilitate the construction of sophisticated models with rich domain knowledge § Speed up solvers by exploiting language properties, compression, and compilation

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Kristian Kersting - Declarative Data Science Machines

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SLIDE 67

Kristian Kersting - Declarative Data Science Machines

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SLIDE 68

Compute Equitable Partition (EP) of the LP using WL Intuitively, we group together variables

  • resp. constraints that interact in the

very same way in the LP.

using$WL$

n P = {P1, . . . , Pp; Q1, . . . , Qq}

Partition of LP variables Partition of LP constraints

Kristian Kersting - Declarative Data Science Machines

[Mladenov, Ahmadi, Kersting AISTATS´12, Grohe, Kersting, Mladenov, Selman ESA´14, Kersting, Mladenov, Tokmatov AIJ´15]

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SLIDE 69

Fractional Automorphisms of LPs The EP induces a fractional automorphism of the coefficient matrix A

where XQ and Xp are doubly-stochastic matrixes (relaxed form of automorphism)

Kristian Kersting - Declarative Data Science Machines

XQA = AXP

(XP )ij = ( 1/|P| if both vertices i, j are in the same P,

  • therwise.

(XQ)ij = ( 1/|Q| if both vertices i, j are in the same Q,

  • therwise
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SLIDE 70

Fractional Automorphisms Preserve Solutions

If x is feasible, then Xpx is feasible, too.

Kristian Kersting - Declarative Data Science Machines

By induction, one can show that left-multiplying with a double-stochastic matrix preserves directions of inequalities. Hence,

$ $

Ax ≤ b ⇒ XQAx ≤ XQb ⇔ AXP x ≤ b

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SLIDE 71

Fractional Automorphisms Preserve Solutions

If x* is optimal, then Xpx* is optimal, too.

Kristian Kersting - Declarative Data Science Machines

Since$by$construncCon$$$$$$$$$$$$$$$$$$$$$$$$$$$and$hence$ $

cT (XP x) = cT x cT XP = cT

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SLIDE 72

What have we established so far?

Instead of considering the original LP It is sufficient to consider i.e. we “average” parts of the polytope.

Kristian Kersting - Declarative Data Science Machines

(AXP , b, XP

T c)

to$consider$

(A, b, c)

But why is this dimensionality reduction?

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SLIDE 73

Dimensionality Reduction

Kristian Kersting - Declarative Data Science Machines

The$doubly7stochasCc$matrix$$$$$$$$$can$be$wriren$ as$$ $ $

BiP = (

1

|P |

if vertex i belongs to part P,

  • therwise.

XP XP = BBT

Since$the$column$space$of$B$is$equivalent$to$the$ span$of$$$$$$$$$,$it$is$actually$sufficient$to$consider$

  • nly$$

$

(ABP , b, BT

P c)

XP

This is of reduced size, and actually we can also drop any constraint that becomes identical