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Reducing wind energy costs is a crucial goal to promote renewable energy and reduce dependencies on fossil fuels, both to fight climate change and to increase energy independence. Two main optimization problems arise during the design of offshore wind farms: the Wind Farm Layout Optimization (WFLO) problem and the Wind Farm Cable Routing (WFCR) problem. The goal of WFLO is to find the optimal turbine locations within a given area to maximize revenues from energy production minus construction costs. The goal of WFCR is to minimize the costs of subsea cables that transfer the electricity produced by turbines. Traditionally, the two NP-hard problems have been studied separately and are solved sequentially, despite being strongly related. The output of WFLO defines the input to WFCR, and their goals are opposing: while larger distances between turbines have a positive effect on WFLO due to reduced wake losses, they negatively impact the cable costs in WFCR. Hence, we study the combined optimization problem, unifying the two problems. We propose a novel heuristic that uses a combined local search to modify solutions of WFLO and WFCR simultaneously. While the combined approach is more computationally demanding than the sequential approach, the proposed method solves industry-scale problems and improves up to 12 million Euro the Net Present Value (NPV) of wind parks, particularly when the energy density is low. Furthermore, the combined approach reduces the up-front investment costs by up to 10%, significantly reducing investment risks, and enabling a faster expansion of wind energy.

Das Unternehmen VeggieMeat produziert Fleischersatzprodukte auf Basis von Erbsenprotein. Der aktuelle Forschungstand bietet kaum Literatur über die Entwicklung einer veganen Bratwurst. Daher hat sich das Ziel ergeben, einen Prototyp mit Rohstoffen des Unternehmens zu entwickeln sowie diesen rheologisch mittels einer Texturanalyse und sensorisch an der FH Wiener Neustadt Campus Wieselburg im Vergleich zu Marktmustern abzutesten. Zuerst wurde durch Store-Checks analysiert, welche Zutaten bei vergleichbaren Marktproben eingesetzt werden. Danach wurde bezüglich der Herstellung einer Brühwurst aus Fleisch und der Entwicklung und Herstellung einer Matrix recherchiert, die der Wurst die nötige Knackigkeit verleihen sollte. Vor Start der Entwicklung wurde eine Bratwurst aus Fleisch sensorisch beschrieben und dadurch die wichtigsten Eigenschaften, die eine Bratwurst definieren, herausgefiltert. In der Entwicklungsphase der veganen Bratwurst wurden diverse Vorversuche hinsichtlich der Festigkeit/Knackigkeit, Farbe und des Geschmacks und der Würzigkeit durchgeführt. Nach Abschluss der Vorversuche wurden die Prozesse aus dem Labor auf Anlagen, welche in der Fleischindustrie im Einsatz sind, angepasst. Mit dem entwickelten Prototyp wurde dann ein Akzeptanztest mit einer Vergleichsprobe des Store-Checks durchgeführt. Mittels der Erweiterung von Just-about-right Fragen wurden mögliche Optimierungspotentiale eruiert. Das Ergebnis der sensorische Abtestung ergab, dass das Aussehen (von außen), der Geschmack und das Mundgefühl einen signifikanten Einfluss auf die Gesamtakzeptanz der Probe hatten. Durch die Durchführung einer Penalty-Analyse konnte festgestellt werden, dass die Festigkeit der veganen Bratwurst von 81 Prozent der Probanden/innen als genau richtig fest empfunden wurde, aber puncto Würzigkeit Optimierungspotential vorhanden war. Im Rahmen der durchgeführten Rangordnungsprüfung wurde die entwickelte vegane Bratwurst von den Testpersonen gegenüber den im Gebiet Niederöster

El aprendizaje de los lenguajes artísticos ayuda a los estudiantes a experimentar procesos de transformación y permite procesos creativos que ayuda a desarrollar mentes más flexibles para la innovación ya la resolución de problemas de manera creativa en cualquier área de la vida. El objetivo de la investigación fue analizar la incidencia de la publicidad en el aprendizaje formal. En el marco de la metodología, la investigación fue transdisciplinar de tipo descriptivo, la interpretación de los resultados resultó cuali-cuantitativo y los instrumentos aplicados: encuesta y focus group y lista de cotejo. La publicidad utilizada como recurso didáctico que se puede implementar en actividades para el diseño y creación de piezas publicitarias a partir de temas generadores, aunque la publicidad no se encuentra implícita en la educación. Se concluye que a través de una serie de actividades educativas se logra fomentar una actitud crítica hacia el consumo para que los estudiantes sepan elegir que necesita consumir.

El aprendizaje de los lenguajes artísticos ayuda a los estudiantes a experimentar procesos de transformación y permite procesos creativos que ayuda a desarrollar mentes más flexibles para la innovación ya la resolución de problemas de manera creativa en cualquier área de la vida. El objetivo de la investigación fue analizar la incidencia de la publicidad en el aprendizaje formal. En el marco de la metodología, la investigación fue transdisciplinar de tipo descriptivo, la interpretación de los resultados resultó cuali-cuantitativo y los instrumentos aplicados: encuesta y focus group y lista de cotejo. La publicidad utilizada como recurso didáctico que se puede implementar en actividades para el diseño y creación de piezas publicitarias a partir de temas generadores, aunque la publicidad no se encuentra implícita en la educación. Se concluye que a través de una serie de actividades educativas se logra fomentar una actitud crítica hacia el consumo para que los estudiantes sepan elegir que necesita consumir.

The cable routing problem in offshore wind farms consists in designing a transportation network to transfer the electricity generated by wind turbines to a central hub (substation) which is connected to shore. The submarine electrical cables are expensive, comprising about 5% of the total capital expenditure (CAPEX) of an offshore wind farm (BVG Associates, 2019). For this reason, the optimization of cable routing has been investigated in literature, with the objective of finding the cable routing of minimum cost (Bauer & Lysgaard, 2015). One important constraint for the cable routing problem is that cable crossings are forbidden, due to the increased installation costs and difficult maintenance. Another constraint is that the routing must avoid all obstacles in the wind farm sea area. These obstacles may be due to unsuitable seabed conditions, to ship wrecks, and to regulations, such as fishing corridors and natural reserves. Cables must not cross any of these areas for the routing solution to be feasible. Acable routing allows only one electrical cable to exit from each turbine, and multiple cables to enter turbines and the substation. Each sub-tree leaving the substation is denoted a rootbranch. A property of cable routing solution is related to how many turbines are present in each root-branch. If the number of turbines in each root-branch is the same or differs at most by one, we denote the solution balanced. While literature mainly has focused on the general unbalanced cable routing problem, in industry the wind farm developers favor balanced cable routing solutions. As the solutions to the balanced problem are a subset of the solutions to the unbalanced formulation, unbalanced solutions may be cheaper than balanced. The drawbacks of the unbalanced routing are related to the additional electrical equipment cost that needs to be installed in the offshore substation. In particular, the cost of installing a spare Offshore Transformer Module (OTM) on the subst

The two main challenges of optimizing a wind farm are the design of the turbine layout and the design of the cable routing. The first task consists in placing each turbine such that overall power production is maximized, the wake effect (wind shadow) between turbines is minimized, and foundation costs are minimized as well. The second task is to select the minimum cost cable routing to connect the turbines with submarine cables, which transfer the produced electricity to a substation and then onshore. Although the typical procedure is to solve the two problems sequentially, we investigate the benefit of solving them together. Few studies in the literature attempt to join these two optimization problems, which are often simplified to keep the computational complexity low. In our work, we model the combined problem with all constraints relevant to practical applications of wind farm design. We also present a novel local search that integrates the two problems, thus allowing the cable routing to give direct feedback to the turbine positions in the layout. We benchmark the combined optimization on a set of realistic industry-scale wind farm instances. Our results show that the combined optimization outperforms the sequential approach, especially for lower energy density wind farms, due to the significant savings in the cable routing which widely compensate for a slight reduction in power production.

In large liner shipping networks, several hundred container vessels operate 24/7,following planned routes and timetables. These networks constantly face unexpected disruptions of varying magnitude. Among the most common reasons are bad weather, port congestions, labour strikes or equipment breakdowns at ports or on vessels. Disruptions may result in delayed vessels, temporarily disabled vessels, reduced port productivity, and port closures. Due to the cargo-driven connectivity of liner shipping networks, even a single delayed vessel can create ripple effects that affect multiple other vessels. Resolving disruptions is a trade-off between minimizing operational vessel costs and port call costs on one side, and minimizing the impact on cargo, such as delays andre-routings, on the other side. We present a model and solution method that generates a set of recovery plans for the decision maker. We present preliminary results for testcases that were developed together with our industrial collaborator Mærsk. We will further discuss various challenges that arise in practice - such as incomplete information and intangible costs - and how we deal with those.

In global liner shipping networks, a large share of transported cargo is transshipped at least once between container vessels, and the total transportation time of these containers depends on how well the corresponding services are synchronized. We propose a problem formulation that integrates service scheduling into the liner shipping network design problem. Furthermore, the model incorporates many industry-relevant modeling aspects: it allows for leg-based sailing speed optimization, it is not limited to simple or butterfly-type services, and it accounts for service-level requirements such as cargo transit time limits. The classic liner shipping network design problem is already a hard problem, and to solve the extended version, we propose a column-generation matheuristic that uses advanced linear programming techniques. The proposed method solves LINER-LIB instances of up to 114 ports and, if applied to the classic liner shipping network design problem, finds new best solutions to all instances, outperforming existing methods reported in the literature. Additionally, we analyze the relevance of scheduling for liner shipping network design. The results indicate that neglecting scheduling and approximating transshipments instead may result in the design of liner shipping networks that underestimate cargo transit times and their implications.

In large liner shipping networks, several hundred container vessels operate 24/7, following planned routes and timetables. These networks constantly face unexpected disruptions of varying magnitude. Among the most common reasons are bad weather, port congestions, labour strikes or equipment breakdowns at ports or on vessels. Disruptions may result in delayed vessels, temporarily disabled vessels, reduced port productivity, and port closures. Due to the cargo-driven connectivity of liner shipping networks, even a single delayed vessel can create ripple effects that affect multiple other vessels. Resolving disruptions is a trade-off between minimizing operational vessel costs and port call costs on one side, and minimizing the impact on cargo, such as delays and re-routings, on the other side. One difficulty of finding a good trade-off arises from the fact that cargo related costs are largely not tangible or directly quantifiable, such as lost reputation and customer churn. Incomplete information during the planning of recovery plans adds another challenge: ports may reject a revised vessel schedule if no berthing window is available, resulting in multiple iterations of recovery planning. We present a model and solution method that generates a set of recovery plans for the decision maker. We present preliminary results for test cases that were developed together with our industrial collaborator Maersk.

Despite a precisely established plan, disruptions are a reality in liner shipping. They are caused by unforeseen factors such as weather, port congestion, low terminal productivity, crane breakdowns etc. Disruptions vary in magnitude. Smaller disruptions, such as the temporary stop of a crane operations due to fog, often impacts only a single vessel. In contrast, the closure of a hub terminal as Algeciras for two days due to rough weather in Gibraltar Straits has severe ripple effects that spread across the entire network. Recovery actions for such major events require rescheduling of multiple vessels, as well as cargo re-routing. Maersk, in cooperation with the Technical University of Denmark, is working on a decision support tool aimed at recovering operations after disruptions of different sizes in near real time. The tool uses an integrated approach that jointly optimizes vessel schedules and cargo routes. The objective is to minimize (a) operational cost, mainly vessel related such as fuel and port stays, and (b) impact on cargo delivery dates. The outcome is "cargo-friendly" revised vessel schedules that recovers operations within a fixed time horizon. The practical considerations and mathematical formulation of the model(s) will be presented together with preliminary computational results.

Global container liner shipping networks are composed of services and each service represents a roundtrip that connects a set of ports following a published schedule. The majority of services is operated at a weekly frequency, and each port on a service is visited at the same time each week. Commonly, all vessels deployed on a service are of the same capacity. Liner services are connected through common port calls that allow liner network operators to move cargo from one service to another. The movement of containers between services is called transshipment and enables large liner shipping companies to transport containers between almost any possible pair of ports around the globe. Current state-of-the-art models and methods (e.g. Karsten et al., 2017) for liner shipping network design problems only determine the routes and sailing speeds for individual services, but approximate transshipment times by a constant. In practice, the transshipment time between two services depends on how well the schedules of the individual services are synchronized. In the network of the world’s largest overseas cargo carrier, around half of all transported containers are transshipped, and the transshipment times may significantly affect the total transit time of containers between their origin and destination port.

We address two problems that affect operational costs as well as the service level of a liner shipping company: The service scheduling problem and the cargo allocation problem. The service scheduling problem aims at determining optimal port call times of liner shipping services. It is a generalization of the simpler speed optimization problem. Different to previous studies (e.g. Guericke and Tierney, 2015) it does not only determine the speed and fuel consumption between subsequent port calls, but also the weekly berth times at each port. In liner shipping networks the schedules of individual liner shipping services establish the transshipment times between pairs of services that call the same port.

We consider a strategic infrastructure and tanker fleet sizing problem in the liquefied natural gas business. The goal is to minimize long-term on-shore infrastructure and tanker investment cost combined with interrelated expected cost for operating the tanker fleet. A non-linear arc-based model and an exact solution method based on a set-partitioning formulation are developed. The latter approach allows very fast solution times. Computational results for a case study with a liner shipping company are presented, including an extensive sensitivity analysis to account for limited predictability of key parameter values, to analyze the solutions’ robustness and to derive basic decision rules.

Den moderne økonomi er afhængig af billig og pålidelig godstransport over hele kloden. Transport ved hjælp af containerskibe udgør et vigtigt element i den globale forsyningskæde. Containerskibe forbinder lande og kontinenter over lange afstande med forholdsvis lave transportomkostninger. Store containerskibsrederier (linierederier) kontrollerer flere hundrede containerskibe der typisk sejler på faster ruter. En enkelt rute deles typisk mellem adskillige containerskibe så hver havn på ruten modtager et besøg af et containerskib fra den pågældende rute en gang om ugen. De enkelte ruter er forbundet via havne, hvor containere kan lastes, losses, men også omlastes mellem skibe. Kombinationen af containerskibsruter og havne danner et kompliceret transportnetværk der muliggør transport af containere mellem de fleste større havne i verden. I denne afhandling præsenterer vi matematiske modellerings- og optimeringsværktøjer, der hjælper beslutningstagere inden for containerskibssejlads til at finde løsninger på komplekse beslutningsproblemer. Beslutningsproblemerne vi adresserer indebærer spørgsmål som: Hvilke havne skal være omfattet af transportnetværket? Hvordan skal hver rute udformes for at opnå et godt forbundet og omkostningseffektivt netværk? Hvordan skal havnebesøg planlægges og synkroniseres mellem ruterne for at give den mest økonomiske og hurtigste transport? På hvilken rute skal containere transporteres, hvis der findes flere muligheder? Artiklerne i denne afhandling bidrager til forskning indenfor operationsanalyse med anvendelse i maritim optimering. Nærmere bestemt fremlægger de to første artikler modeller og løsningsmetoder til design og re-planlægning af store netværk indenfor containerskibsfart. Artiklerne kombinerer og udvider modelleringsegenskaberne væsentligt i forhold til tidligere bidrag og mindsker afstanden mellem akademiske prototyper og de reelle problemstillinger so, The modern economy relies on cheap and reliable transportation of goods all around the globe. Liner shipping networks represent an important link in the global supply chain, as they connect countries and continents over long distances at comparatively low transportation costs. In largeliner shipping networks, several hundred container vessels operate more than a hundred shipping routes. The individual routes are linked through ports, where containers can be loaded, unloaded but also be transshipped between shipping routes. The resulting networks constitute inherently complex systems. In this thesis we present mathematical modeling and optimization tools that help decision makers in the liner shipping industry to find solutions to complex decision problems. The decision problems we address involve questions like: Which ports shall be covered by the network? How shall each single shipping route be designed to achieve a well-connected but cost-efficient network? How shall port calls be scheduled and synchronized between shipping routes to offer the most economical and fastest transportation between ports? On which route shall containers be transported, if multiple options exist? The articles in this thesis contribute to the field of Operations Research with application in maritime optimization. More particularly, the first two articles present models and solution methods to (re-)design and (re-)schedule large liner shipping networks. The articles combine and substantially extend modeling features of previous contributions and narrow the gap to the economic and operational reality of liner shipping. The results obtained from solving the models shed light on previously unexamined issues. The developed solution algorithms cannot only handle the increased complexity inherent to the models, but improve over existing methods proposed in the literature. The third article addresses a strategic infrastructure and tanker fleet sizing problem as part of an industrial case study w