Keynotes

 Professor of Applied Quantitative Analysis,
Director of Industrial Liaison,
Director of the Centre for Cryptocurrency Research and Engineering
in the Department of Computing, Imperial College London, UK

Bio:

William Knottenbelt is Professor of Applied Quantitative Analysis, Director of Industrial Liaison, and Director of the Centre for Cryptocurrency Research and Engineering in the Department of Computing at Imperial College London, where he became a Lecturer in 2000.  He has co-authored more than 200 scientific papers, is an editor of Performance Evaluation Journal, and has served as general or program chair of numerous conferences and workshops related to quantitative modelling and/or cryptocurrencies, most recently ACM/SPEC ICPE 2024 and IEEE ICBC 2024. A keen supporter of student-led innovation, he is technical advisor to a number of start ups including Deep Render, Aventus and DeepSearch Labs.
Abstract: 
In proof-of-work blockchains, difficulty regulates the rate at which blocks are produced by miners in an effort to avoid producing new units of cryptocurrency too quickly. Over the years, several different algorithms for adjusting difficulty have been proposed, some of which have led to severe problems such as oscillation in the Bitcoin Cash. The recent bitcoin halving took place around 8 months ahead of the ideal schedule. In this talk we take a look at the state of the art in this area, and propose a new algorithm which is able to adjust difficulty on a block-by-block basis while keeping block production close to an ideal schedule.

Professor of Business Analytics at Southampton Business School, the University of Southampton, UK
Member of the Centre for Operational Research, Management Science and Information Systems (CORMSIS),
Director of Internationalisation at Southampton Business School

Bio:

Stephan Onggo is a Professor of Business Analytics at Southampton Business School, the University of Southampton and a member of the Centre for Operational Research, Management Science and Information Systems (CORMSIS). Currently, he holds the position of Director of Internationalisation at Southampton Business School. He serves as an Associate Editor (Agent-Based Simulation) for the Journal of Simulation, Area Editor (Simulation) for Flexible Services and Manufacturing Journal, and a General Council member of The OR Society. His research interests lie in the areas of simulation and its interface with other Data Analytics methods. He is particularly interested in simulation modelling methodology (symbiotic simulation/digital twin, hybrid modelling, agent-based simulation, discrete-event simulation, simulation optimisation) and its applications in the management of supply chain, health care and disaster. He was the Principal Investigator of an EPSRC funded project to designing a resilient relief supply network for natural disasters in West Java Indonesia using optimisation-via-simulation (Relief-OpS) and the co-Investigator of an EPSRC funded project to improve the community resilience and sustainability through Operational Research capacity building in Southeast Asia (CREST-OR).


Abstract: 

In recent years, there has been a significant rise in the number of works related to Digital Twin (DT) technology. A key element of a DT is the digital representation of a physical object, process, or system that decision-makers aim to evaluate or manage. One of the most commonly used forms of digital representation is a simulation model. Traditionally, simulation has been used mainly in offline contexts. However, with the advent of DT technology, it is now possible to establish an effective online connection between a simulation model and its physical counterpart, enabling simulations to be integrated into dynamic control systems for real-time decision-making. In this talk, I will explore whether various steps in simulation modeling methodology, such as conceptual modeling, input modeling, model development, validation, and output analysis, need to be adapted for DT applications.

Associate Professor and Deputy Head of the Institute of Production and Logistics
at BOKU University, Vienna, Austria

Bio:

Patrick Hirsch is an associate professor and deputy head of the Institute of Production and Logistics at the BOKU University in Vienna. He serves as study programme coordinator for the doctoral studies in social and economic sciences in his university. Patrick has (co-)authored numerous scientific journal articles and book chapters. He works as an associate editor for the Flexible Services and Manufacturing Journal and is member of the board of the Austrian Operations Research Society. He has also led several national and international research projects. Patrick is co-founder of the company ingentus decision support KG, which provides tailored decision support systems for organizations in health care and the wood-processing industry. His research interests include sustainable logistics, health care logistics, food logistics, and disaster management.

Authors of the presentation:
Patrick Hirsch, Yvonne Kummer
 
Abstract:
This presentation deals with the impact of an African swine fever (ASF) outbreak in Austria. ASF is one of the most significant and critical diseases for the global domestic pig population. Hence, the authors evaluated control strategies and identified bottlenecks during an ASF outbreak. A hybrid approach was selected, including discrete-event and agent-based simulation. An extended Susceptible-Exposed-Infectious-Recovered (SEIR) model (within a pig farm) and a standard SEIR model (between pig farms) were used to simulate the chain of infection. A total of 576 scenarios with several parameter variations were calculated to identify the influence of external factors on key performance indicators. The main results show a comparison between two control strategies anchored in law: a standard strategy (SS) and a preventive culling strategy (SC). The calculated scenarios show a difference between these strategies and indicate that with SC during an outbreak, fewer farms would be infected, and fewer pigs would be culled. Furthermore, specific geographical areas were identified, which—due to their density of pigs and farms—would be severely affected in case of an ASF outbreak. The analysis of bottlenecks in rendering plants (RPs) showed an increase in the number of days RPs were overutilized as the transmission rate increased. In addition, SS caused more days of overutilized RPs than SC.
 
The presentation is based on the paper:
Kummer Y., Fikar C., Burtscher J., Strobl M., Fuchs R., Domig K.J., Hirsch P. (2022): Facilitating Resilience during an African Swine Fever Outbreak in the Austrian Pork Supply Chain through Hybrid Simulation Modelling. Agriculture (Switzerland), 12 (3), art. no. 352
DOI: 10.3390/agriculture12030352