Pre-Specific Modeling - Computational Machines in Coexistence with Urban Data Streams

PhD Candidate: Vahid Moosavi

Supervisor: Ludger HovestadtCo-supervisor: Barbara Hammer

Pre-Specific ModelingComputational Machines in Coexistence with Urban Data Streams

27th of April 2015ETH Zurich

Tuesday, 28 April, 15

The Landscape of Computational Urban Modeling

Research (In a Concrete Level)

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Applied Domains



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Applied Domains

Mod

elin

g C

once

pts



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If one scans 5 bn books from 1900 (Google n-gram)


And if we just follow the market?!

Google Trends 4


And if we just follow the market?!

Google Trends

RQ: But What are the underlying paradigms and abstract concepts behind these patterns?

andHow architects and urban designers can

be proactive contributors in this domain?

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Approach of this research (how to be abstract but operational?)

1.It is not adequate to talk about individual modeling approaches. Instead, we need abstract and philosophical research in computational modeling in order to discuss the foundations. (Toward this, we tried to formalize “pre-specific modeling” as a way of thinking in computational urban modeling.)

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Approach of this research (how to be abstract but operational?)

1.It is not adequate to talk about individual modeling approaches. Instead, we need abstract and philosophical research in computational modeling in order to discuss the foundations. (Toward this, we tried to formalize “pre-specific modeling” as a way of thinking in computational urban modeling.)

2.Further, if the developed concepts and ideas are true then they should work in different applied domains(Therefore, we implemented the developed concepts in different applied domains.)

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First partConceptual Set up of Pre-Specific Modeling

(Toward formalizing the elements of a modeling approach)

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Specific Modeling Pre-Specific Modeling


The issue of Representation

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Selected'Features'to'Represent'the'Objects'

Objects'

Examples:*•  Ci-es*•  Streets*•  Buildings*•  People*•  Companies*•  Food**•  Energy*•  Medicine*•  Internet*•  Words*in*a*text*

Each concrete object is an instance of a generic object, defined a-priori

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A

B



Objects'


Each concrete object is a feature for itself related to other objects based on concrete

relations


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A

B



Objects'


Each concrete object is a feature for itself related to other objects based on concrete

relations


Abstract Universals Concrete Universals 7



The Issue of Causality

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The Rule8




The Rule Any Rule8



The role of Data

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The role of Data

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Classical SpaceSyntax, London “The social logic of space”1984

Structured and designed data


The role of Data

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Classical SpaceSyntax, London “The social logic of space”1984

GPS Trajectory of Taxicabs, Beijing, 2012

Structured and designed data Unstructured and indirectly produced data streams


Second partComputational Machines that aligns with the concept of pre-specific modeling

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Markov ChainsSelf Organizing Maps


Obs

erve

d

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Specific ModelingSelected'Features'to'Represent'the'Objects'

Objects'


Obs

erve

dModel

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Objects'


Obs

erve

dModel

Fourier Decomposition

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Objects'


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Pre-Specific ModelingA

B


Learned Dictionary of Forms in Co-existence with Data12


B


Learned Dictionary of Forms in Co-existence with Data

Self Organizing Map (SOM)

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B


Functions of Self Organizing Map (SOM) •Nonlinear function approximation •Time series prediction•Classification•Clustering•Representation Learning•Dimensionality Reduction•Topological Data Analysis (TDA)•Nonparametric Probability Density Estimation

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Functions of Self Organizing Map (SOM) •Nonlinear function approximation •Time series prediction•Classification•Clustering•Representation Learning•Dimensionality Reduction•Topological Data Analysis (TDA)•Nonparametric Probability Density Estimation

An Open Source Python Librarybased on parallel processing

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Third partApplications and Experiments

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Applications

•Urban Traffic Modeling Using Data Streams

•Urban Air Pollution Modeling

•Contextual Mapping

•Modeling the Dynamics of Real Estate Market

•Other experiments in different domains:•Financial Markets

•Biological Systems

•Atmospheric Environments

•Natural Language Processing and Text Modeling

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First ApplicationUrban Traffic Modeling Using Data Streams

Moosavi, Hovestadt 2013 16


Objects'



Moosavi, Hovestadt 2013

State of the art: Agent Based ModelingNeeds the grammars and rules of transport in advance like a languageTo be validated by the classical data such as surveys

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Objects'



Moosavi, Hovestadt 2013

State of the art: Agent Based ModelingNeeds the grammars and rules of transport in advance like a languageTo be validated by the classical data such as surveys

Using GPS tracks of cars as data streamsIn an analogy to spoken language, taking urban cells as a word in a language, each individual driver is a unique story teller, while driving within urban grid cells…

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Objects'

A

B


First ApplicationUrban Traffic Modeling Using Urban Data Streams

GPS$Trajectory$of$Taxicabs,$Beijing$

Road$communi;es$based$on$movement$of$the$cars$not$just$the$physical$road$network$

highly$cri;cal$areas$for$the$whole$traffic$flow$

Areas$with$high$poten;al$of$traffic$jam$

Moosavi, Hovestadt 2013 17


Second ApplicationUrban Air Pollution Modeling

•State of the art: CFD models•Based on idealized models of the fluid movements and numerical methods (Given Priors)•With many simplifying assumptions on the ambient level•Limited in resolution and integration•Computational complexity

Moosavi, Aschwanden, Velasco 2015 18


Second ApplicationUrban Air Pollution Modeling

•State of the art: CFD models•Based on idealized models of the fluid movements and numerical methods (Given Priors)•With many simplifying assumptions on the ambient level•Limited in resolution and integration•Computational complexity

•Using only 3% of direct measurements at the ground level •Plus more than 80 urban parameters using SOM, we were able to estimate the aerosol levels of the whole region with a reasonable accuracy (Cross Validated)•Further, we were able to detect the most informative candidate locations for monitoring stations (which are expensive)Moosavi, Aschwanden, Velasco 2015 18


Third Application

Contextual MappingOr how to create personalized images of the space?

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Third ApplicationContextual Mapping

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Top down or the bottom up Map“The image of the city”

The MapTuesday, 28 April, 15


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Any MapThe MapTuesday, 28 April, 15


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Any Map

Individualized and context dependent Maps“Any image of the city”

The MapTuesday, 28 April, 15

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How to look at a city with huge amount of data? “Digital Opacity?”

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How to look at a city with huge amount of data? “Digital Opacity?”

Is it possible that instead of a top-down map, we provide a simple mapping process?

“Toward designing the process of any map”

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Age + Health22


Method: Learn a one dimensional dictionary and take its elements as an ordered set of numbers. (Computing with contextual numbers)

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Age + Health

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Crime Categories

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Contextual MappingRacial Mixture in New York City?

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Contextual MappingRedistricting and the will of the people

How polarized is Colorado in different elections?Is there any bottom up approach to define the electoral borders?

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Fourth Application

Modeling the Dynamics of Real Estate Market

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Monthly Median Price per sq.ft of sold houses of each Zip code in the state of

Florida 29


One of the Basics of Spa0al Modelingis Spa0al Correla0ons

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Classical Notion of Space(First Law of Geography)

One of the Basics of Spa0al Modelingis Spa0al Correla0ons

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As an alternative: to create a space of temporal patterns

SOM$

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As an alternative: to create a space of temporal patterns

SOM$

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This space can be based on any other aspects too.

(It is a Time Varying Random Field)


Two notions of space

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Experimental,set,up,Forecast,model,

d#%me#steps#Price#of#zone#i#in#future#

Price#in#the#selected#neighbors#

Price#in#the#target#Zone#

TIme#

Time#lag#

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22"

Experimental,set,up,Forecast,model,

Price"in"the"selected"neighbors"

Price"in"the"target"Zone"

Different"neighborhoods"in"different"methods"

Based,on,the,trained,SOM,Classical:,Based,on,physical,proximity,

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Experimental,set,up,Forecast,model,Parameters:,Es5ma5on,methods:,Linear,Regression,,Ridge,,,Bayesian,Ridge,,Knn,,…,,Time,Lag,:,15,months,(based,on,several,runs),Number,of,neighboring,zones,,K:,0,to,40,Predic5ons,ahead,=,12,months,,Training,Data:,from,1996P,No.,of,zones:,300,Before,fiTng,the,model,we,reduce,the,dimensions,using,PCA,,Measure,of,quality,of,predic5on:,Mean,Absolute,Rela5ve,Error,,ARE,,=,|prealPppredicted|/preal,

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Modeling the Dynamics of Real Estate MarketResults'

Predic-ng:'2005406401'from'12'months'in'advance' 36


Modeling the Dynamics of Real Estate MarketResults'

Predic-ng:'2006404401'from'12'months'in'advance' 37



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Results'

Predic-ng:'2013509501'from'12'months'in'advance'38



Most of the times (>80%), we get better results with looking to the new space!

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Modeling the Dynamics of Real Estate MarketSpatial Distribution of Error

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Summary of this research

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•Since computational technologies have become a dominant factor in urban design and modeling...



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•Since computational technologies have become a dominant factor in urban design and modeling...•In order to have a pro-active role in this domain, the designers needs to be computationally literate, not just (expert) users of the computational products.



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•Since computational technologies have become a dominant factor in urban design and modeling...•In order to have a pro-active role in this domain, the designers needs to be computationally literate, not just (expert) users of the computational products. •Toward this goal as a first step, we tried to formalize the abstract notion of pre-specific modeling as a conceptual alternative to the state of the art in computational urban modeling and simulation.



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•Further, we investigated the applicability of a certain category of generic computational methods that encapsulate the complex real phenomena in a co-existence with urban data and depend less on prior domain specific theories.



Summary of this research Publications•5 conference paper presentations•1 journal paper accepted•1 journal paper submitted•3 working papers •1 forthcoming book (Co-editor)

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•Further, we investigated the applicability of a certain category of generic computational methods that encapsulate the complex real phenomena in a co-existence with urban data and depend less on prior domain specific theories.



thank YOU

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Pre-Specific Modeling - Computational Machines in Coexistence with Urban Data Streams

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