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Messages - david.barton@nina.no

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1
OpenNESS / OpenNESS forum
« on: April 07, 2014, 06:47:15  »
Hello,

Is this forum available only to  OpenNESS members?

Regard,

David

2
OpenNESS / zero intervals and benefit cost analysis
« on: April 07, 2014, 06:43:12  »

I tried implementing zero intervals in the Learning Wizard (Hugin 8.0)  for the variable “wtp” (willingness-to-pay for water quality improvement) , using Discretize Manual in the Preprocessor, using the tab-delimited datafile (see attached).

What did I expect as a result?  I expected to see the interval 0-0 in CPT for “wtp”  with zero probability across all parent states (“user_type”, “dist”, “qual”).  As far as I know there are no simulation results for “wtp” exactly equal to zero,  but I still need the interval to appear in the CPT with zero probability (I don’t expect Hugin Wizard to drop intervals without observations, but maybe this happens).

Why do I need this?   Later I manually create the state “none” for the node “qual” to represent ‘water quality improvement is none’.   I then want to attach a 100% probability to a 0-0 interval in “wtp” indicating that there is exactly zero willingness to pay for water quality improvement equals “none”.  Without the 0-0 interval I have to assign an equal probability to the intervals -1000-0 and 0-1000 to capture the idea, but I lose information with a “fuzzy zero” of this kind.

This may sound trivial, but it is a key feature of integrating monetary valuation method results with DPSIR modelling in BBNs, and then conducting cost-benefit analysis of decisions.

Can you help?

Kind Regards,
David

P.S. How do I attach Hugin files to this "topic?"

3
Environmental Management / Catchment run-off model
« on: September 03, 2010, 16:43:08  »
Bayesian network methodology was used in the catchment of Storefjorden, South Eastern Norway, to integrate models of phosphorus (P) abatement costs and effects, as well as models of lake P and eutrophication dynamics. The Bayesian network integrated model was used to explore and evaluate the probable (and improbable) outcomes and uncertainties of (i) the eutrophication problem and (ii) the cost-effectiveness analysis of the corresponding abatement measures. In addition, factors which affect the reliability of transferring cost-effectiveness data for nutrient abatement measures between river basins were detected with a view to informing Norwegian implementation of the EU Water Framework Directive, and the relative uncertainty of model components within the Bayesian influence network was evaluated, with an aim to uncovering "information gaps" in abatement planning, and as a tool for prioritising future eutrophication research.  

Demonstration of the catchment run-off submodel:
http://demo.hugin.com/index.php/Catchment_phosphorous_run-off_network,_Morsa_Norway

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