Jrising at 03:12, 17 October 2012

2012-10-17T03:12:26Z

New page

<slide header="none" center="both">
= Open World Project =
Friday Forum
Oct. 19, 2012
</slide>

<slide title="Talk Plan">
* Other Projects of Interest
* Motivation and Vision
* Core Elements
* Case Study Projects
* Unified Model of Everything
* Next Steps
</slide>

<slide title="Other Projects of Interest">
* Carbon Transition Working Group
* Himalayan Melt and Flooding
* Peruvian Spatial Fisheries
* Web-Weaver
* Slider Extension
</slide>

<slide title="Introduction">
Many of the human behaviors that drive climate change and
environmental degradation are deeply embedded in our society,
economy, and government, and are mutually reinforcing. Better
modeling of human-natural systems can help in many ways:
* Analyzing feedback loops can help identify '''leverage points''', where small policy changes can have pervasive
impacts.
* Allowing models at diverse scales and contexts to
interact can help scientists '''integrate knowledge'''.
* Interactive models can facilitate '''communication'''
with policymakers and make complex problems intelligible.

The Open Model is a modeling framework aimed at these issues.
</slide>

<slide title="Applicability">
* Systemically intractable due over-determined, reinforcing drives, and spatially heterogeneous.
* Environmental and public health issues
* environmental degradation, agricultural practices in poor countries, obesity, substance abuse, groundwater use, and fishery management
* rebound effects and cross-border shifts (e.g., carbon leakage)

<delay>
'''Something for everyone!'''
</delay>
</slide>

<slide title="Big Proposals">
* Fisheries Project
* Climate Behaviors
</slide>

<slide title="Core Elements">
* Amalgamated Modeling
* Multiple Network Maps
* Networked System Dynamics
* Computational Tools
* Integrating Data
* Open Interface
</slide>

<slide title="Amalgamated Modeling">
[[File:Blobs.png]]
</slide>

<slide title="Amalgamated Modeling">
Coupling causes feedback, and models are defined at different scales.

Amalgamated modeling allows models to interact, specialize, and "overlap".
</slide>

<slide title="Bayesian Coupling">
[[File:Amalgelt.png]]
</slide>

<slide title="Bayesian Coupling">
For a variable <math>\theta</math> described by multiple models, each
model provides both a PDF across values at a given time <math>t</math>
when run in isolation, <math>p(\theta, \bar{S}^i)</math>, and a
distribution that includes feedback effects, <math>p(\theta, \tilde{S}^i)</math>. The final distribution is
<math>
p(\theta | \cdot) \propto p(\theta) \prod_i p(\theta |
\bar{S}^i)^\lambda p(\theta, \tilde{S}^i)^{1-\lambda}
</math>
</slide>

<slide title="Multiple Networks">
Models use multiple networks simultaneously
* Different paths on which stocks flow
* Structured disaggregations into classes
* Capturing network properties
</slide>

<slide title="Multiple Networks in Ohio">
[[File:Ohionet.png]]
</slide>

<slide title="Networked System Dynamics">
[[File:Netstocks.png]]
</slide>

<slide title="Networked System Dynamics">
[[File:Ohiomod.png]]
</slide>

<slide title="Networked System Dynamics">
Spatial variation matters

[[File:ssdarch-mod.png]]
</slide>

<slide title="Self-Similar Networks">
[[File:Selfsimodel.jpeg]]
</slide>

<slide title="Computational Tools">
* Evaluate model performance
* Identify driving feedback loops
* Identify tipping and leverage points
* Construct simplified models for communication
* System Regression: construct models from data
</slide>

<slide title="Open Interface">
* A '''Website Interface''' would allow researchers to explore
the model, run tests, and contribute models. For
policy-makers, the online interface would provide ways to
interact with the model, see results, and outline scenarios.
</slide>

<slide title="Intelligent Variables: Dimensions">
* <math>3</math> vs. <math>3 [tonnes]</math> vs. <math>1350487537 [seconds since Jan. 1, 1970]</math>
* Dimensional analysis at the heart of science
* Automatic model checking, unit conversion
</slide>

<slide title="Intelligent Variables: Maps">
"Maps" are dimension-aware functions in space-time, often tied to data streams (e.g., IRI tsvs, geotiffs).
Maps of different resolutions can be manipulated transparently. Example:

GeographicMap<double>& degreeDayMelt = (degreeDayFactor + degreeDaySlope * elevation) * (snowCover / 100) * (surfaceTemp - ZERO_CELSIUS) * (surfaceTemp >= ZERO_CELSIUS);

* elevation is a static map at <math>1 km</math> resolution
* surfaceTemp is a daily varying map at <math>.25^\circ</math> resolution, read from the file 1 day at a time
* snowCover is a weekly varying map at <math>.33^\circ</math> resolution, reconstructed for past years
</slide>

<slide title="Intelligent Variables: Relations">
Variables can represent relationships or differential equations between other variables.

Example (the heat equations):
<syntaxhighlight lang="cpp">
q = -k * Grad(u);
Diff(u) = (-1 / c_p * rho) * Div(q);
</syntaxhighlight>

The equations themselves are saved within <code>q</code> and <code>Diff(u)</code>, so the model can be run.
</slide>

<slide title="Networked Equations Language">
Custom '''Modeling Language''' combines a units-aware equation-like syntax with networks and GIS.

capacity = 1e10 [tons];
rate = 0.0077 [tons/year];
biomass = Stock(1e7 [tons]);
catches = TimeSeries("catches.tsv", [tons/year]);
biomass += rate * biomass * (1 - biomass / capacity) - catches;

print(biomass[0:100], "\t");
</slide>

<slide title="Toolbox">
Transparently combine Matlab, R, shell scripting, Mathematica and other code.
</slide>

<slide title="Integrating Data">
* Calibration
* Validation
* Filling in missing models
</slide>

<slide title="Unified Model of Everything">
[[File:Architecture.png]]
</slide>

<slide title="How Many Variables?">
{| World3/2000 || 283 |-
| System Dynamics National Model || 2000+ |-
| Encyclopedia of World Problems and Human Potential || 56,135 |-
|  environmental feedback loops || 2,675 |}
</slide>

<slide title="Case Study: Networked Economics">
[[File:Netmap_ext.png]]
</slide>

<slide title="Case Study: Hydrological Modeling">
[[File:Distrib.png]]
</slide>

File:Netmap ext.png - Revision history

Jrising at 03:12, 17 October 2012