Archive for the ‘Data Science’ Category

Model Thinking Part 3 – Coarsera

Tipping Point

  • Can be direct cause which is something causes the tip — small action or event (small change in variable) has large impact on end state — this depends also on context
  • Can be contextual  (percolation model is example) which means something in context changes to permit tip – a slight change in the context (environment)can have a big impact on final state
  • Between and within class — system can go within the class from one state to another or the system can go between states across systems

Note:  4 types of systems: equilibrium , periodic, random, complex

Percolation Model – physics model – water percolating down into ground is example

use a checker board model with filled in squares to show tipping point (59.27%) at which a process goes from start to finish (end) used in information flow, forest fire prediction, innovation flow, social model (context changes if more connections are made)

Diffusion Model –  natural diffusion but no tipping point

W sub t (time) = W sub-t (time) (current state) + N * c(number * contact rate) * t (tau – transmission rate) * W sub-t (time) /N (people with disease  / number) * (W sub-t (time) – N / N)

SIS– S (for susceptible), I (for infectious) and S (for susceptible). epidemiology —  non-linear – diffusion model  but person can get cured than reinfected — has a tipping point because people can be cured — this can alos apply to information

W sub t (time) = W sub-t (time) (current state) + N * c(number * contact rate) * t (tau – transmission rate) * W sub-t (time) /N (people with disease  / number) * (W sub-t (time) – N / N) – a [# of people cured)W (sub t) — this can be simplified using standard algebra notation

Basic Reproduction Number is R sub 0 = ct/a then if R sub 0> 1 disease spreads , hence a tipping point

V = % vaccinated  so R sub0(1 – V) = r sub 0 he< or equal to V nce 1 – 1/R sub 0 = number to vaccinate — must get to the number to vaccinate percentage (R sub 0) to create the tipping point needed to protect those people not vacinnated.  If R sub 0 < or + 1, no spread of disease, but if / or > than 1, disease will spread

Economic Models

Real growth is growth – inflation

Linked Data Graph Orientated Frameworks

January 9, 2012 Comments off

Glossary of Semantic Technology Terms

The Rationale for Semantic Technologies

Ontologies as Conceptual Models

The Rationale for Semantic Technologies

JSON-LD by Manu Sporny!

Semantic Web Intro by Manu Sporny

Linked Data Intro by Manu Sporny

Linked Data FAQ

Linked Data – Welcome to the Data Network (may behind a pay wall)


Google Pregel Graph Processing

Pregel: a system for large-scale graph processing – “ABSTRACT”

Pregel a system for larescale graph processing slides



Data Sources

December 18, 2011 Comments off

Welcome to NYC Open Data

Common Crawl

Public Sector Information – Raw Data for New Services and Products

Data Science

August 15, 2011 Comments off