Ein personen- und aufgabengenauer Ansatz zur robusten Einsatzplanung von Flugpersonal mittels Optimierung und Simulation

In der vorliegenden Arbeit wird ein personen- und aufgabengenauer Ansatz zur robusten Einsatzplanung von Flugpersonal vorgestellt. Es wird beschrieben, wie Methoden der mathematischen Optimierung und der diskreten Simulation weiterentwickelt und kombiniert werden, um es Verkehrs- und Einsatzplanern zu ermöglichen, die Qualität ihrer Planungsergebnisse zu erhöhen und diese noch vor deren Umsetzung auf ihre dynamischen Eigenschaften hin untersuchen zu können. So wird die anonyme Einsatzplanung zunächst in Form einer klassischen Crew Pairing Problemformulierung abgebildet, die sämtliche Zusammenhänge und Nebenbedingungen der Planung anonymer Personalumläufe beinhaltet. Hierauf aufbauend wird unter Hinzunahme personen- und aufgabenindividueller Aspekte wie Qualifikationen und Anforderungen ein Ansatz zur Planung individueller Personalumläufe entwickelt: das Job Pairing Problem. Um die Alltagstauglichkeit der Optimierungsergebnisse zu gewährleisten, werden in dessen Rahmen gleichzeitig sowohl bewährte, auf Robustheit abzielende Planungsindikatoren als auch eigens entwickelte Konzepte zur effizienteren Nutzung der Personalressource berücksichtigt. Unter Verwendung von Verfahren der multikriteriellen Optimierung und unter Einbeziehung von Planungspräferenzen werden diese heterogenen und teilw. gegenläufigen Zielsetzungen innerhalb der Problemformulierung berücksichtigt. Weiterhin werden in der Arbeit mit der ShiftJob-Nachbarschaftsrelation und der SingleBranch&Price-Heuristik Ansätze vorgestellt, die in Kombination mit etablierten exakten und heuristischen Optimierungsverfahren zur Bestimmung zulässiger und qualitativ hochwertiger Lösungen herangezogen werden können. Um die Alltagstauglichkeit der durch die Optimierung erstellten Einsatzpläne sicherstellen zu können, wird in dieser Arbeit darüber hinaus ein Simulationsmodell entwickelt, das sämtliche relevanten Flugzeug- und Personalprozesse innerhalb des operativen Flugverkehrs abbildet und auch mögliche Störungen während der Planumsetzung berücksichtigt. Um auch das operative Management und deren auf Störereignisse ausgerichteten Recoverystrategien zu integrieren, werden ausgewählte Handlungsalternativen abgebildet, die insbesondere den Bereich des Crew-Recovery mit seinen verschiedenen Einsatzformen der Flugdienstreserve abdecken. Es wird die programmtechnische Umsetzung des Modells in Form einer plattformunabhängigen und leicht zu erweiternden Simulationsanwendung beschrieben. Abschließend werden durch Validierung und Anwendung dieses Programms dessen korrektes Verhalten und dessen Nützlichkeit sowohl für wissenschaftliche als auch praktische Fragestellungen nachgewiesen. Entstanden ist diese Arbeit im Rahmen des Projekts Computer Aided Traffic Scheduling (CATS), das am Lehrstuhl von Prof. Dr. Ewald Speckenmeyer am Institut für Informatik der Universität zu Köln ins Leben gerufen und das zwischenzeitlich als Kooperation mit der Technischen Hochschule Köln, der Kölner Verkehrs-Betriebe AG (KVB) und der Lufthansa CityLine fortgeführt wurde. Innerhalb dieses Projektes werden schon seit Jahren Planungsprobleme aus dem Verkehrsbereich untersucht, immer mit dem Ziel, diese effizienter und insbesondere im Hinblick auf deren Störungsanfälligkeit robuster lösen zu können

A simulation based approach on robust airline job pairing

Job paring, i.e. the composition of duty rosters from single activities, is an important part of the airline operations planning process. With labor costs being a major factor in an airline's cost structure, such personnel schedules have to ensure efficiency to be of practical relevance. At the same time they have to improve customer acceptance by offering best possible robustness, keeping inevitable local delays from spreading through the airline's flight network. In this paper we present a project currently in development which aims for generating robust personnel schedules for airline operations. The resulting tool set will allow us to effectively allocate flight personnel, using optimization and simulation techniques to generate and compare schedules with respect to their applicability and their demand for standby personnel, and to evaluate them prior to their implementation in the field. This paper begins with a short introduction of the airline planning process, focusing on the job pairing problem. We then describe our project, presenting our optimization and simulation approaches

Agent based modeling and simulation of a pastoral-nomadic land use system

Almost half of Africa is covered by arid savannas, which are used as rangelands and are the source of livelihood for a vast population. To sustain pasture quality, degradation has to be avoided and efficient and sustainable land use strategies are needed. This paper describes the development of a simulation model representing the range management strategies of the Himba people in north-western Namibia. The model recognizes spatial factors and the impact of management decisions on ecosystem dynamics. The paper also describes the process of creating and validating a software application, and implementing the model

Agent based modeling and simulation of a pastoral-nomadic land use system

Almost half of Africa is covered by arid savannas, which are used as rangelands and are the source of livelihood for a vast population. To sustain pasture quality, degradation has to be avoided and efficient and sustainable land use strategies are needed. This paper describes the development of a simulation model representing the range management strategies of the Himba people in north-western Namibia. The model recognizes spatial factors and the impact of management decisions on ecosystem dynamics. The paper also describes the process of creating and validating a software application, and implementing the model

Agent-based modeling and simulation of individual traffic as an environment for bus schedule simulation

To re-establish the regular driving operations of a tram network, which was disturbed significantly by unforeseen external events, traffic schedulers apply rescheduling and rerouting strategies. These strategies are usually multi-modal; they consider the interaction of trams, buses, even taxis. Thus, to evaluate the applicability of a given rescheduling or rerouting strategy prior to its implementation in the real-world system, a multi-modal simulation software is needed. In this article we present an agent-based model of individual traffic which will be applied as background to a planned simulation of bus traffic. These combined models are to be integrated with an existing tram schedule simulation; the resulting multi-modal model will then be applied to evaluate the usefulness of given rescheduling or rerouting strategies. After a short introduction to agent-based modeling and simulation, as well as to existing models of individual traffic, this paper proposes to model the behavior of individual traffic as an environment for agent-based bus schedule simulation. Finally, some experiments are conducted by modeling and simulating individual traffic in Cologne's highly frequented Barbarossaplatz area

Agent-based modeling and simulation of individual traffic as an environment for bus schedule simulation

To re-establish the regular driving operations of a tram network, which was disturbed significantly by unforeseen external events, traffic schedulers apply rescheduling and rerouting strategies. These strategies are usually multi-modal; they consider the interaction of trams, buses, even taxis. Thus, to evaluate the applicability of a given rescheduling or rerouting strategy prior to its implementation in the real-world system, a multi-modal simulation software is needed. In this article we present an agent-based model of individual traffic which will be applied as background to a planned simulation of bus traffic. These combined models are to be integrated with an existing tram schedule simulation; the resulting multi-modal model will then be applied to evaluate the usefulness of given rescheduling or rerouting strategies. After a short introduction to agent-based modeling and simulation, as well as to existing models of individual traffic, this paper proposes to model the behavior of individual traffic as an environment for agent-based bus schedule simulation. Finally, some experiments are conducted by modeling and simulating individual traffic in Cologne's highly frequented Barbarossaplatz area

Worldwide LCOEs of decentralized off-grid renewable energy systems

Recent events mean that the security of energy supplies is becoming more uncertain. One way to achieve a more reliable energy supply can be decentralised renewable off-grid energy systems, for which more and more case studies are conducted in research. This review gives a global overview of the costs, in terms of levelised cost of electricity (LCOE), for these autonomous energy systems, which range from $0.03/kWh to about$1.00/kWh worldwide in 2021. The average LCOEs for 100% renewable energy systems have decreased by 9% annually between 2016 and 2021 from $0.54/kWh to$0.29/kWh, presumably due to cost reductions in renewable energy and electricity storage. Our overview can be employed to verify findings on off-grid systems, and to assess where these systems might be deployed and how costs are evolving

"FAIR-by-Design" Artifacts: Enriching Publications and Software with FAIR Scientific Information at the Time of Creation

Presentation on the idea of "FAIR-by-Design" Artifacts at the NFDI4Ing Conference 2023. Abstract In several research disciplines, the use and development of software have become an integral part, with researchers reporting in publications the results obtained with software and concepts implemented in software. Consequently, publications and software have become two core artifacts in academia with increasing importance for measuring research impact and reputation. The research community has made great efforts to improve digital access to publications and software. However, even now that these artifacts are available in digital form, researchers still encapsulate the scientific information in static and relatively unstructured documents unsuitable for communication. The next step in the digital transformation of scholarly communication requires a more flexible, fine-grained, context-sensitive, and semantic representation of scientific information to be understandable, processable, and usable by humans and machines. Researchers need support in the form of infrastructures, services, and tools to organize FAIR scientific information from publications and software. Several research disciplines work on initiatives to organize scientific information, e.g., machine learning with “Papers-with-Code”, invasion biology with “Hi-Knowledge”, and biodiversity with “OpenBiodiv”. However, these initiatives are often technically diverse and limited to the respective application domain. For this reason, we from the task area Ellen of NFDI4Ing (and in collaboration with NFDI4DataScience and NFDI4Energy) decided to use the Open Research Knowledge Graph (ORKG), an innovative infrastructure for organizing scientific information from publications and software. The ORKG is a cross-discipline research knowledge graph that offers all research communities an easy-to-use and sustainably governed infrastructure. This infrastructure implements best practices, such as FAIR principles and versioning, with services combining manual crowd-sourcing and (semi-)automated approaches to support researchers in producing, curating, processing, and (re-)using FAIR scientific information from publications and software. As a result, organized scientific information is openly available in the long term and can be understood, processed, and used by humans and machines. Thus, research communities can constantly build, publish, maintain, (re-)use, update, and expand organized scientific information in a long-term and collaborative manner. While the ORKG currently focuses on organizing scientific information from published publications and software, we aim to help researchers create “FAIR-by-Design” artifacts to improve their storage, access, and (re-)use, using the ORKG as exemplary infrastructure. The idea of “FAIR-by-Design” artifacts is that the creators of an artifact describe it with extensive and FAIR information once and in parallel to the time of creation. This FAIR information is embedded directly into the artifact to be available to anyone at any time. Specifically, we developed two tools (SciKGTeX for publications and DataDesc for software) that support researchers in the role of author and developer to enrich their publications and software at the time of writing and development with FAIR scientific information embedded into the respective artifact. SciKGTeX is a LaTeX package to annotate research contributions directly in LaTeX source code. Authors can enrich their publications with structured, machine-actionable, and FAIR scientific information about their research contributions. SciKGTeX embeds the annotated contribution data into the PDF’s XMP metadata so that the FAIR scientific information persists for the lifetime of the artifact. DataDesc is a toolkit that combines different tools to describe software with machine-actionable metadata. Developers can describe Python software and its interfaces with extensive metadata by annotating individual classes and functions directly within the source code. DataDesc converts all metadata into an OpenAPI-compliant YAML file, which various tools can render and process. Regarding the research data management (RDM) lifecycle, both tools target the production phase to support researchers in creating“FAIR-by-Design” artifacts. Creating “FAIR-by-Design” artifacts helps to improve their storage, leading to better access to artifacts and thus laying the foundation for their effective (re-)use. Using the ORKG as exemplary infrastructure, we demonstrate with two proof-of-concepts how infrastructure providers can use the artifacts from SciKGTeX and DataDesc to store the FAIR scientific information in their systems. In the case of SciKGTeX, the ORKG recently added a new upload feature for SciKGTeX annotated PDFs to allow researchers to add the FAIR scientific information of publications quickly and easily. In addition, the ing.grid journal provides a version of their LaTeX template that integrates the SciKGTeX. For DataDesc, we plan such an upload feature and similar use by the community in future work. Researchers only need to create a “FAIR-by-Design” artifact once, and can reuse it on multiple infrastructures to improve their dissemination and discoverability. With improved storage, researchers can more easily discover and access publications and software to determine whether an artifact fulfills their information needs. However, researchers do not have to rely on such infrastructures to find, access, and assess publications or software. When they encounter a “FAIR-by-Design” artifact, it embeds the additional information itself so that they can review the artifact themselves with the same information base. Improved discoverability and accessibility lay the foundation for effective (re-)use as researchers can better understand an artifact. In the case of the ORKG, we can even (re-)use the information from SciKGTeX and DataDesc stored in the ORKG interchangeably. A publication annotated with SciKGTeX can reference a software annotated with DataDesc stored in the ORKG and vice versa. Overall, enabling researchers to create “FAIR-by-Design” artifacts is a promising approach to support the downstream phases of storage, access, and (re-)use in the RDM lifecycle. In our presentation, we want to explain the idea of “FAIR-by-Design” artifacts in more detail using concrete examples based on the two tools and in combination with the ORKG. We believe that the idea of “FAIR-by-Design” artifacts is of interest to the research community. The two tools can inspire other researchers to extend our original approaches and develop new ones to create more “FAIR-by-Design” artifacts by enriching artifacts with FAIR scientific knowledge at the time of creation. Furthermore, we hope to encourage and motivate researchers to use our tools more intensively and thus establish them. In particular, the existing and planned future integration with ORKG and the existing collaboration with the ing.grid journal are motivating incentives for researchers to use SciKGTeX and DataDesc actively.The authors thank the Federal Government, the Heads of Government of the Länder, as well as the Joint Science Conference (GWK), for their funding and support within the NFDI4Ing and NFDI4DataScience consortia. This work was funded by the German Research Foundation (DFG) -project numbers 442146713 and 460234259, by the European Research Council for the project ScienceGRAPH (Grant agreement ID: 819536), and by the TIB - Leibniz Information Centre for Science and Technology

Architectural Concept and Evaluation of a Framework for the Efficient Automation of Computational Scientific Workflows: An Energy Systems Analysis Example

Scientists and engineers involved in the design of complex system solutions use computational workflows for their evaluations. Along with growing system complexity, the complexity of these workflows also increases. Without integration tools, scientists and engineers are often highly concerned with how to integrate software tools and model sets, which hinders their original research or engineering aims. Therefore, a new framework for streamlining the creation and usage of automated computational workflows is introduced in the present article. It uses state-of-the-art technologies for automation (e.g., container-automation) and coordination (e.g., distributed message oriented middleware), and a microservice-based architecture for novel distributed process execution and coordination. It also supports co-simulations as part of larger workflows including additional auxiliary computational tasks, e.g., forecasting or data transformation. Using Apache NiFi, an easy-to-use web interface is provided to create, run and control workflows without the need to be concerned with the underlying computing infrastructure. Initial framework testing via the implementation of a real-world workflow underpins promising performance in the realms of parallelizability, low overheads and reliable coordination

Wealth-in-people and practical rationality: aspirations and decisions about money in South Africa

This article explores crucial decisions made by Sylvia, a Xhosa woman living in the townships of Cape Town, during a period of approximately thirty years. These decisions involved large sums of money and had important consequences for her own life, for those of her son and grandchild, and for the relationships she had with her first and second husbands and in‐laws. Sylvia's decisions continued to be influenced by gendered ways of belonging to ancestors and descendants but also show important changes in connecting wealth and people. The wealth‐in‐people approach offers important insights into how Sylvia's decisions are guided by power and control over people as well as by prestige. However, it also becomes evident that the wealth‐in‐people approach does not sufficiently explain or theorize the agency of people. By drawing on the philosophical notion of practical rationality as a complementary analytical perspective, I explore agency in relation to aspirations and the acquisition of new open‐ended values. The perspective offered by practical rationality increases our understanding of how individual decisions, especially complex decisions around money, are made because of their transformative potential and the aspiration to cultivate oneself.Horizon 2020(H2020)Global Challenges (FSW