Category:Optimization
About the optimization tool
For PlanWise an optimization tool is available for formulating and solving LP and MIP problems. For the problem formulation, a graphical user interface to the ZIMPL optimization modelling language has been developed. For solving a problem, external third-party solvers have been linked to the program. Currently, the solvers available are
- LPSolve, which is freely available, and
- ILOG CPLEX, which is a very efficient, state-of-the-art solver. However, it is commercial and requires that the user has a licence.
The optimization model is linked to a Heureka-formatted SQL Server database used for storing input data, simulation data, and result data. This enables a seamless integration with the input data required by the optimization model, as well as direct presentation of optimization results in the form of tables, graphs, and maps. This simplifies the analysis and visualization of scenarios or plans of forest development and outputs.
As an alternative to the integrated optimization tool, an AIMMS model has been developed, which may be more suitable for a OR researcher or the very advanced user who needs maximum flexibility or maximum optimization performance. This model is also linked to the same database, but is run as a separate application. It also requires an AIMMS licence.
With integrated optimization tool, a number of basic models will be developed. A user should be able to use these as they are, or as a starting point for further development.
Optimization models developed or under development
===Non-spatial model for analyzing sustainable cut and other values (available)
Harvest scheduling with clustering of old growth areas and harvest areas
Harvest scheduling including road access, AAC constraints, opening size constraints, and harvest flow constraints
Other options
Ongoing research
We have had the pleasure of hosting a finnish postdoc during 2007-2008, dr Tero Heinonen. He has developed a software application in which optimization algorithms are combined with cellular automata to solve spatial problems when raster cells are used as description units instead of stands. The application can read from the Heureka database directly and could become available in the future.