Editor's Column: Primal Needs, Primary Concerns

Column Generation based Primal Heuristics

In the past decade, significant progress has been achieved in developing generic primal heuristics that made their way into commercial mixed integer programming (MIP) solver. Extensions to the context of a column generation solution approach are not straightforward. The Dantzig-Wolfe decomposition principle can indeed be exploited in greedy, local search, rounding or truncated exact methods. Th...

New developments in the primal-dual column generation technique

The classical column generation is based on optimal solutions of the restricted master problems. This strategy frequently results in an unstable behaviour and may require an unnecessarily large number of iterations. To overcome this weakness, variations of the classical approach use interior points of the dual feasible set, instead of optimal solutions. In this paper, we address the primal-dual...

Large-scale optimization with the primal-dual column generation method

The primal-dual column generation method (PDCGM) is a general-purpose column generation technique that relies on the primal-dual interior point method to solve the restricted master problems. The use of this interior point method variant allows to obtain suboptimal and well-centered dual solutions which naturally stabilizes the column generation. A reduction in the number of calls to the oracle...

Learning disabilities: individual needs or categorical concerns?

Despite the fact that the field of learning disabilities has grown dramatically in recent years, many questions remain unanswered or disputed. In the absence of a clear definition of learning disabilities, the authors suggest that it has become an educational simile with children described as "like a learning disabled child." It is postulated that the learning disabled label has become reflecti...

Guest Editors’ Column Reading Sideways: Middlebrow into Modernism