Blar i Bergen Open Research Archive på forfatter "Haugland, Dag"

Comparison of Discrete and Continuous Models for the Pooling Problem
Alfaki, Mohammed; Haugland, Dag (Chapter; Peer reviewed, 2011)The pooling problem is an important global optimization problem which is encountered in many industrial settings. It is traditionally modeled as a bilinear, nonconvex optimization problem, and solved by branchandbound ... 
Fixed cardinality stable sets
Samer, Phillippe; Haugland, Dag (Journal article; Peer reviewed, 2021)Given an undirected graph G=(V,E) and a positive integer k in {1, ..., V}, we initiate the combinatorial study of stable sets of cardinality exactly k in G. Our aim is to instigate the polyhedral investigation of the ... 
Integer Programming Formulations for the Shared Multicast Tree Problem
Ivanova, Marika; Haugland, Dag (Peer reviewed; Journal article, 2019)We study the shared multicast tree (SMT) problem in wireless networks. To support a multicast session between a set of network nodes, SMT aims to establish a wireless connection between them, such that the total energy ... 
A model for optimal fleet composition of vessels for offshore wind farm maintenance
GutierrezAlcoba, Alejandro; Ortega, Gloria; Hendrix, Eligius M.T.; HalvorsenWeare, Elin Espeland; Haugland, Dag (Peer reviewed; Journal article, 2017)We present a discrete optimisation model that chooses an optimal fleet of vessels to support maintenance operations at Offshore Wind Farms (OFWs). The model is presented as a bilevel problem. On the first (tactical) level, ... 
Modelling overfow using mixed integer programming in short‑term hydropower scheduling
Litlabø, Tormod; Aaslid, Per; Riise, Tarjei Lid; Haugland, Dag (Journal article; Peer reviewed, 2023)Shortterm hydropower scheduling seeks to find a production schedule that maximizes profit, but must also consider the hydrological balance and risk of overflow. Overflow is by nature a nonlinear and nonconvex phenomenon. ... 
On offshore wind farm maintenance scheduling for decision support on vessel fleet composition
GutierrezAlcoba, Alejandro; Hendrix, Eligius M.T.; Lopez, Gloria Ortega; HalvorsenWeare, Elin Espeland; Haugland, Dag (Peer reviewed; Journal article, 2019)Maintenance costs account for a large part of the total cost of an offshore wind farm. Several models have been presented in the literature to optimize the fleet composition of the required vessels to support maintenance ... 
Optimization of reliable cyclic cable layouts in offshore wind farms
Klein, Arne; Haugland, Dag (Peer reviewed; Journal article, 2020)A novel approach for optimizing reliable cable layouts in offshore wind farms is presented. While optimization models traditionally are designed to suggest acyclic cable routes, those developed in this work recognize that ... 
Polyhedral results and stronger Lagrangean bounds for stable spanning trees
Samer, Phillippe; Haugland, Dag (Journal article; Peer reviewed, 2023)Given a graph G=(V,E) and a set C of unordered pairs of edges regarded as being in conflict, a stable spanning tree in G is a set of edges T inducing a spanning tree in G, such that for each {ei,ej}∈C, at most one of the ... 
Pooling Problems with SingleFlow Constraints
Haugland, Dag (Chapter; Peer reviewed, 2019)The pooling problem is a frequently studied extension of the traditional minimum cost flow problem, in which the composition of the flow is subject to restrictions. In a network consisting of three layers of nodes, the ... 
Solving the pooling problem with LMI relaxations
Frimannslund, Lennart; El Ghami, Mohamed; Alfaki, Mohammed; Haugland, Dag (Chapter; Peer reviewed, 2012)We consider the standard pooling problem with a single quality parameter, which is a polynomial global optimization problem occurring among other places in the oil industry. In this paper, we show that if the feasible set ... 
Strategic optimization of offshore wind farm installation
Backe, Stian; Haugland, Dag (Lecture Notes in Computer Science, Chapter; Peer reviewed; Journal article, 2017)This work describes logistical planning of offshore wind farm (OWF) installation through linear programming. A mixed integer linear programming (MILP) model is developed to analyze costeffective port and vessel strategies ... 
Towards stronger Lagrangean bounds for stable spanning trees
Samer, Phillippe; Haugland, Dag (Chapter, 2022)Given a graph G=(V,E) and a set C of unordered pairs of edges regarded as being in conflict, a stable spanning tree in G is a set of edges T inducing a spanning tree in G, such that for each {e_i, e_j} in C, at most one ... 
The unsuitable neighbourhood inequalities for the fixed cardinality stable set polytope
Samer, Phillippe; Haugland, Dag (Chapter, 2021)Given an undirected graph G = (V, E) and an integer k∈{1,…,V} , we initiate the combinatorial study of stable sets of cardinality exactly k in G. Our aim is to instigate the polyhedral investigation of the convex hull ...