Das Forschungsseminar der Fakultät findet mittwochs von 16.30 bis 17.30 Uhr via Zoom statt. Der Zugang wird über die Mailingliste verschickt.
|18.11.2020||Prof. Dr. Lars Norden, Brazilian School of Public and Business Administration|
|25.11.2020||Prof. Dr. Dirk Briskorn, Bergische U Wuppertal|
|Anarchy in the Uj: Coordination Mechanisms for Maximizing the Number of On-Time Jobs |
We consider the distributed scheduling problem on parallel machines with the central objective of maximizing the number of on-time jobs. Jobs are self-interested utility-maximizers that can choose the machines they are processed on in order to reduce their own completion time or tardiness. Each machine processes the jobs according to a local policy. We discuss Nash equilibria in the resulting schedules and perform a thorough analysis of the resulting (absolute) prices of anarchy for various parallel machine environments, utilities of the agents, and local policies of the machines. We show that local policies that are based on simple sorting-based procedures like SPT and EDD lead to big losses in welfare compared to the global optimum. However, when employing Moore-Hodgson's algorithm as a local policy, we can prove a price of anarchy of $(2m-1)/m$ for uniform machines and a price of anarchy of $2$ for related and unrelated parallel machines. Moreover, we show how these results can be used to prove approximation ratios for greedy scheduling algorithms.
|02.12.2020||Martin Kanz, World Bank|
|13.01.2021||Prof. Galina Zudenkova, Ph.D., U Mannheim|
|27.01.2021||Prof. Mark Le Quement, U of East Anglia (UK)|
|03.02.2021||Karsten Kiekhäfer, FernUni Hagen, and Christian Thies, TU Braunschweig|
|Towards a carbon-neutral fleet of passenger cars in 2050 – a dynamic stock and flow analysis |
Motivated by the urgent need to curb greenhouse gas emissions from transportation, we investigate alternative pathways towards a carbon-neutral fleet of passenger cars in 2050. For the analysis, a dynamic stock and flow model is developed. The model simulates the evolution of the fleet composition in terms of vehicle age, powertrain technologies, and fuel and energy consumption based on aging-chain structures. Fleet emission are assessed over the whole vehicle life cycle with a special emphasis on upstream emissions from fuel and electricity production. The model is applied to the German market of passenger cars to determine transition pathways that lead to a carbon-neutral vehicle fleet in 2050 and acknowledge the remaining carbon budget for limiting global warming according to the IPCC targets. We show that staying within the carbon budget is possible for different scenarios. A prerequisite, however, is a coordinated action between the transport and the energy sector, aiming at a simultaneous uptake of the deployment of electric vehicles, renewable energies, and green fuels. For a carbon-neutral fleet in 2050, additional measures such as carbon sequestration or offsetting become necessary. We estimate the magnitude of the required measures and discuss the feasibility of their implementation.