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In the veneer cutting industry tree trunks are peeled into thin veneer strips which are cut, glued together, and pressed into bentwood pieces for seats, backrests, etc. In this work, a model for optimizing the inherent cutting problem with respect to resource efficiency is presented. Especially the heterogeneous quality of the wood renders existing models for classic cutting stock problems useless...
The travelling salesperson problem with hotel selection (TSPHS) is a recently proposed variant of the travelling salesperson problem. Currently, the approach that finds the best solutions is a memetic algorithm. However, this approach is unsuitable for applications that require very short computation times. In this paper, a new set-partitioning formulation is presented along with a simple but powerful...
This is the traditional triennial note used by the Editors to give the readers of 4OR information on the state of the journal and its future. In the three years that have passed since the last editorial note (Liberti et al. in 4OR 10(1):1–13, 2012), three volumes (each containing four issues) of the journal have been published: vol. 10 (2012), vol. 11 (2013) and vol. 12 (2014)....
The paper addresses the problem of strategic base stations placement in cognitive radio networks. We consider a primary user, operating on the frequency channels of a primary network, and an operator (a leader) facing the competition of a second operator (a follower). These operators are willing to exploit the unused capacity of the primary network and maximize their profits derived from operating...
We consider a variance minimization problem for semi-Markov decision processes with state-dependent discount factors in Borel spaces. The reward function may be unbounded from below and from above. Under suitable conditions, we first prove that the discount variance minimization criterion can be transformed into an equivalent expected discount criterion, and then show the existence of a discount variance...
Many cutting problems on two- or three-dimensional objects require that the cuts be orthogonal and of guillotine type. However, there are applications in which the cuts must be orthogonal but need not be of guillotine type. In this paper we focus on the latter type of cuts on rectangular bins. We investigate the so-called $$L$$ L -approach, introduced by Lins et al. (J Oper Res Soc 54:777–789,...
This paper presents a new Lagrangian heuristic to solve the general capacitated single item lot sizing problem (CSILSP) where the total costs of production, setup, and inventory are to be minimized. We introduce a pre-smoothing procedure to transform the problem into a CSILSP with non-customer specific time windows and relax constraints that are specific to the CSILSP. The resulting uncapacitated...
The Unit Commitment problem in energy management aims at finding the optimal productions schedule of a set of generation units while meeting various system-wide constraints. It has always been a large-scale, non-convex difficult problem, especially in view of the fact that operational requirements imply that it has to be solved in an unreasonably small time for its size. Recently, the ever increasing...
We outline a relatively new research agenda aiming at building a new approximation paradigm by matching two distinct domains, the polynomial approximation and the exact solution ofNP-hard problems by algorithms with guaranteed and non-trivial upper complexity bounds. We show how one can design approximation algorithms achieving ratios that are “forbidden” in polynomial time (unless a very unlikely...
An automatic method for constructing linear relaxations of constrained global optimization problems is proposed. Such a construction is based on affine and interval arithmetics and uses operator overloading. These linear programs have exactly the same numbers of variables and inequality constraints as the given problems. Each equality constraint is replaced by two inequalities. This new procedure...
In this paper, we study the problem of joint placement and routing, both in the deterministic and stochastic cases, arising in the field of compilation of dataflow applications for manycore architectures. A GRASP algorithm is first proposed for solving the deterministic version and extended afterwards to treat the chance-constrained program with uncertainty affecting the weights of a dataflow process...
This paper proposes a pricing game among a manufacturer and two competing suppliers. One of the suppliers establishes an ingredient brand, which can enhance the valuations of the end products. The equilibrium is derived to investigate the impact of the ingredient brand awareness and the production costs on the suppliers’ pricing competition, the manufacturer’s product mix and retail price(s), and...
In this paper, we introduce a new extension of the bottleneck transportation problem where additionally auxiliary resources are needed to support the transports. A single commodity has to be sent from supply to demand nodes such that the total demand is satisfied and the time at which all units of the commodity have arrived at the demand nodes is minimized. We show that already the problem with a...
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