The problem considered in this paper is a real world problem. It concerns the management of the deliveries of coal to the several plants of a coke industry firm in order to meet the demand of several clients at minimal purchasing, transportation and production cost. The problem is solved using a column generation technique. At the lower level, a mix of one ton satisfying all the client quality ...

The C-bound, introduced in Lacasse et al. [2006], gives a tight upper bound on the risk of the majority vote classifier. Laviolette et al. [2011] designed a learning algorithm named MinCq that outputs a dense distribution on a finite set of base classifiers by minimizing the C-bound, together with a PACBayesian generalization guarantee. In this work, we design a column generation algorithm that...

In examination timetabling we have to assign the exams of a given set of courses to time slots, such that conflicting exams are assigned to different time slots. We study the problem that occurs at our department. The characteristics of this problem are as follows. The exams have to take place in 5 days, and per day there are 2 time slots. Teachers can express their preferences for the time slo...

Linear chains and trees are basic building blocks in many applications of graphical models, and they admit simple exact maximum a-posteriori (MAP) inference algorithms based on message passing. However, in many cases this computation is prohibitively expensive, due to quadratic dependence on variables’ domain sizes. The standard algorithms are inefficient because they compute scores for hypothe...

We consider optimization problems that consist in minimizing a quadratic function under an atomic norm1 regularization or constraint. In the line of work on conditional gradient algorithms, we show that the fully corrective Frank-Wolfe (FCFW) algorithm — which is most naturally reformulated as a column generation algorithm in the regularized case — can be made particularly efficient for difficu...

We consider planning of freight train classification at hump yards using integer programming. The problem involves the formation of departing freight trains from arriving trains subject to scheduling and capacity constraints. To increase yard capacity, we allow the temporary storage of early freight cars on specific mixed-usage tracks. The problem has previously been modeled using a direct inte...

Parallel machine scheduling problems concern the scheduling of n jobs on m machines to minimize some function of the job completion times. If preemption is not allowed, then most problems are not only NP-hard, but also very hard from a practical point of view. In this paper, we show that strong and fast linear programming lower bounds can be computed for an important class of machine scheduling...

Container terminals offer transfer facilities to move containers from vessels to trucks, trains and barges and vice versa. Within the terminal the container yard serves as a temporary buffer where incoming containers are piled up in stacks. Only the topmost container of each stack can be accessed. If another container has to be retrieved, containers stored above it must be relocated first. Cont...

We study the problem of multi-person pose estimation in natural images. A pose estimate describes the spatial position and identity (head, foot, knee, etc.) of every non-occluded body part of a person. Pose estimation is difficult due to issues such as deformation and variation in body configurations and occlusion of parts, while multi-person settings add complications such as an unknown number...

The integral simplex method for set partitioning problems allows only pivots-on-one to be made, which results in a primal all-integer method. In this technical note we outline how to tailor the column generation principle to this method. Because of the restriction to pivots-onone, only local optimality can be guaranteed, and to ensure global optimality we consider the use of implicit enumeratio...