O slideshow foi denunciado.
Utilizamos seu perfil e dados de atividades no LinkedIn para personalizar e exibir anúncios mais relevantes. Altere suas preferências de anúncios quando desejar.
Statistical Physics, Network
theory & Big data
An approach to human mobility

Oleguer Sagarra
Dept. Física Fonamental,
Uni...
A killing combination...
Statistical Physics
&
Big Data
“New Social Sciences”
2
Why?
We want to study Human Mobility…

Mobility has deep implications in many processes..
(contagion, spread of ideas...)
...
What?
(Human) Mobility is a rather complex process…
Different scales (Micro/Meso/Macro)
Society is heterogeneous… (Humans ...
But we don’t need
modelling…
“Computers are useless, they can only
give you answers…” (P. Picasso)
This talk is about ques...
How?
Theoretical
Physics
Mathematics

Empirical
Real (big) Data

Network Science

6
The data... (has problems)
a) How to get it?
Private companies
(Social Media)

Citizens

7
Getting the data... Experiments
Smartphones give lots of “sensing opportunities”
Citizen science aims to involve people in...
Getting the data...
Social Media
b) Is it biased?
(Big data can also mean big errors)

9
Social media data
Social media data is geolocalized, we can extract
trajectories from it.
But first, is the data representa...
The data... is geolocalized,
and (too) big!
c) Continuous vs discrete data
From points to a network?
(We want only the flow...
The network approach
Data
Filtering
Aggregation (grid)
Network

12
Network data

(We can now apply network metrics
and… data is normalized!)
Sagarra, O. Master Thesis. http://upcommons.upc....
Now we know how to deal
with the data...

We want to detect “abnormal” patterns...
What is chance, what is not?
What is im...
Modeling as a physicist…
Take all trivial elements out…
Keep just the “basic” factors in mobility
!

- Distance / Cost (a....
Macro/Meso level:
(urban/regional/national)

We need a general model for mobility networks…

Taking inspiration from Stati...
We need a null model for the
data...
Procedure:
1. Fix some hypothesis
“The population leaving or entering each cell is gi...
Roadmap
Raw data
Experiments, Databases...

Prediction
(Product)

Data treatment tools

Statistical Validation
Hypothesis....
What’s the goal of all this?
Understand what drives human mobility
Discriminate important factors from negligible ones
(po...
osagarra@ub.edu
@usagarra

Thanks for your attention...

20
Próximos SlideShares
Carregando em…5
×

Networks, Big Data and Statistical Physics: A killing combination

1.514 visualizações

Publicada em

Publicada em: Educação, Tecnologia, Negócios
  • DOWNLOAD FULL BOOKS, INTO AVAILABLE FORMAT ......................................................................................................................... ......................................................................................................................... ,DOWNLOAD FULL. PDF EBOOK here { https://tinyurl.com/yyxo9sk7 } ......................................................................................................................... ,DOWNLOAD FULL. EPUB Ebook here { https://tinyurl.com/yyxo9sk7 } ......................................................................................................................... ,DOWNLOAD FULL. doc Ebook here { https://tinyurl.com/yyxo9sk7 } ......................................................................................................................... ,DOWNLOAD FULL. PDF EBOOK here { https://tinyurl.com/yyxo9sk7 } ......................................................................................................................... ,DOWNLOAD FULL. EPUB Ebook here { https://tinyurl.com/yyxo9sk7 } ......................................................................................................................... ,DOWNLOAD FULL. doc Ebook here { https://tinyurl.com/yyxo9sk7 } ......................................................................................................................... ......................................................................................................................... ......................................................................................................................... .............. Browse by Genre Available eBooks ......................................................................................................................... Art, Biography, Business, Chick Lit, Children's, Christian, Classics, Comics, Contemporary, Cookbooks, Crime, Ebooks, Fantasy, Fiction, Graphic Novels, Historical Fiction, History, Horror, Humor And Comedy, Manga, Memoir, Music, Mystery, Non Fiction, Paranormal, Philosophy, Poetry, Psychology, Religion, Romance, Science, Science Fiction, Self Help, Suspense, Spirituality, Sports, Thriller, Travel, Young Adult,
       Responder 
    Tem certeza que deseja  Sim  Não
    Insira sua mensagem aqui

Networks, Big Data and Statistical Physics: A killing combination

  1. 1. Statistical Physics, Network theory & Big data An approach to human mobility Oleguer Sagarra Dept. Física Fonamental, University of Barcelona 1
  2. 2. A killing combination... Statistical Physics & Big Data “New Social Sciences” 2
  3. 3. Why? We want to study Human Mobility… Mobility has deep implications in many processes.. (contagion, spread of ideas...) The development of GPS/mobile phone technologies makes gathering data cheap and possible at large scale. 3
  4. 4. What? (Human) Mobility is a rather complex process… Different scales (Micro/Meso/Macro) Society is heterogeneous… (Humans are not “monkeys”… in principle!) But we are physicists! So we will try to model it anyway… 4
  5. 5. But we don’t need modelling… “Computers are useless, they can only give you answers…” (P. Picasso) This talk is about questions rather… “Models push the boundaries of our understanding" 5
  6. 6. How? Theoretical Physics Mathematics Empirical Real (big) Data Network Science 6
  7. 7. The data... (has problems) a) How to get it? Private companies (Social Media) Citizens 7
  8. 8. Getting the data... Experiments Smartphones give lots of “sensing opportunities” Citizen science aims to involve people in data collection, sharing and processing BeePath: Experiments on human mobility http://bee-path.net (Btw: Very interesting project, but don’t have time for it today) 8
  9. 9. Getting the data... Social Media b) Is it biased? (Big data can also mean big errors) 9
  10. 10. Social media data Social media data is geolocalized, we can extract trajectories from it. But first, is the data representative from the population? (We want info about people, not about “some people that tweet a lot”) We can compare with the census… Analysis must be done at user level! 10
  11. 11. The data... is geolocalized, and (too) big! c) Continuous vs discrete data From points to a network? (We want only the flows: From where and to where people go, “on average”) 11
  12. 12. The network approach Data Filtering Aggregation (grid) Network 12
  13. 13. Network data (We can now apply network metrics and… data is normalized!) Sagarra, O. Master Thesis. http://upcommons.upc.edu/pfc/handle/ 2099.1/13134 13
  14. 14. Now we know how to deal with the data... We want to detect “abnormal” patterns... What is chance, what is not? What is important, what is not? 14
  15. 15. Modeling as a physicist… Take all trivial elements out… Keep just the “basic” factors in mobility ! - Distance / Cost (a.k.a. laziness) - Population density (a.k.a. opportunities) (We look for causality, not correlation) 15
  16. 16. Macro/Meso level: (urban/regional/national) We need a general model for mobility networks… Taking inspiration from Statistical Mechanics and Network Theory, one can define flexible null models. 16
  17. 17. We need a null model for the data... Procedure: 1. Fix some hypothesis “The population leaving or entering each cell is given” ! (quite a lot of maths….)* 2. Generate predictions “How do the flows organize?” ! 3. Compare Data vs Prediction Sagarra, O. et altr. Phys. Rev. E 88, 062806 (2013) 17
  18. 18. Roadmap Raw data Experiments, Databases... Prediction (Product) Data treatment tools Statistical Validation Hypothesis... Modelling (We are here) Clean data Null Model predictions Data features Visualizations 18
  19. 19. What’s the goal of all this? Understand what drives human mobility Discriminate important factors from negligible ones (population density, distance, cost...) Create tools to study data in an unbiased manner 19
  20. 20. osagarra@ub.edu @usagarra Thanks for your attention... 20

×