We study the problems of multi-person pose segmentation in natural images and instance segmentation in biological images with crowded cells. We formulate these distinct tasks as integer programs where variables correspond to poses/cells. To optimize, we propose a generic relaxation scheme for solving these combinatorial problems using a column generation formulation where the program for genera...

We present a review of column generation formulations for the Routing and Wavelength Assignment (rwa) problem with the objective of minimizing the blocking rate. Several improvements are proposed together with a comparison of the different formulations with respect to the quality of their continuous relaxation bounds and their computing solution ease.

This paper describes how to use the AGU package (AGUTEX) for producing manuscripts, preprints, and camera-ready copy, together with an unofficial extension package called AGU. This extension adds extra features such as author-year citations with BibTEX and true figures in the preprint version. Other extra features include corrected coding to avoid having to give certain numbers explicitly, subl...

In this paper, we present one generalization of the famous capacitated p-median location problem, called budget constraint multi-capacitated location problem (MCLP). This generalization is characterized by allowing each facility to be used with different capacity levels. We consider n customers, m facilities and l capacity levels, we note that the solution shape of MCLP can be represented as a ...

A subgradient method for solving large linear programs is implemented and analyzed in a column generation framework. A performance comparison of the implementation is made versus the commercial linear programming solver XPress. Computational results from tests using data from airline crew scheduling, in particular crew rostering, show that the method performs very well in a column generation sc...

We introduce a hybrid approach integrating CP-based Column Generation and pure CP methods. It is being applied to the large scale optimization problem of Airline Crew Assignment. The combination of methods from CP and OR results in an algorithm that overcomes the inherent weaknesses of each approach. First numerical results show the superiority of the hybrid algorithm in comparison to direct CP...

Abstract: In this paper, we develop a simultaneous column-and-row generation algorithm that could be applied to a general class of large-scale linear programming problems. These problems typically arise in the context of linear programming formulations with exponentially many variables. The defining property for these formulations is a set of linking constraints, which are either too many to be...

A column generation approach for tramper ship routing problems is studied. We show that an efficient algorithm can be obtained by decomposing the problem into two simple problems. The master problem of the column generation is a set partitioning problem and the subproblem is the time-dependent shortest path problems with time windows. Numerical results of problems using general-purpose integerp...

We study the problem of instance segmentation in biological images with crowded and compact cells. We formulate this task as an integer program where variables correspond to cells and constraints enforce that cells do not overlap. To solve this integer program, we propose a column generation formulation where the pricing program is solved via exact optimization of very small scale integer progr...

Branch-and-price algorithms combine a branch-and-bound search with an exponentiallysized LP formulation that must be solved via column generation. Unfortunately, the standard branching rules used in branch-and-bound for integer programming interfere with the structure of the column generation routine; therefore, most such algorithms employ alternate branching rules to circumvent this difficulty...