17.6 Other Hybridisation Forms
This module has covered a few forms of hybridisation between ic
There are a variety of problem decomposition techniques that support
other forms of hybridisation. Three forms which employ linear duality
are Column Generation, Benders Decomposition and Lagrangian Relaxation.
All three forms have been implemented in ECLiPSe and used to solve
large problems, and the ECLiPSe library colgen, described in
the next chapter, supports Column Generation.
Often it is useful to extract several linear subproblems and apply a
separate linear solver to each one. The eplex library offers
facilities to support multiple linear solvers. Space does not permit
further discussion of this feature.
Cooperating solvers have been used to implement some global
constraints, such as piecewise linear constraints .
Linearisation of ic global constraints
is another method of achieving tight cooperation.
Finally many forms of hybridisation involve different search
techniques, as well as different solvers. For example stochastic
search can be used for probing instead of a linear solver, as described
In conclusion, ECLiPSe provides a wonderful environment for exploring
forms of hybridisation.