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Publications
Publications (39)
Offshore wind energy is experiencing a rising importance for many electricity markets. While the effects of wind energy overall on electricity prices have been thoroughly studied, it remains unknown if offshore wind has a different impact on electricity prices than onshore wind. The aim of this paper is therefore to estimate the effect of offshore...
We consider two systems of nonlinear first‐order ordinary differential equations proposed to describe Ca2+‐levels in renal vascular smooth muscle cells and in liver cells. Initially, we present the models and its assumptions. We next investigate an approach to local solvability by Picard–Lindelöf 's Theorem. Further, we prove nonnegativity of the s...
The rapidly growing city of Kigali has a bus network that is undergoing increased development as underlined in its Transport Master Plan. Two schemes of bus driver remuneration coexist in the city: One constitutes a hybrid salary and commission system, while the other pays a fixed monthly salary. This paper examines the effect of these differing co...
Everyday commuting as a mobility phenomenon is well-investigated and has been the topic of many contributions.
Nevertheless, the distinct determinants of the commuting professional’s motivation to regularly travel comparably long distances have not been in the focus of research yet.
Thus, this contribution analyses the sociodemographic variables th...
Mobility and transportation service requirements change with growing age. Also in a car-based society like Germany many seniors need to give up driving the car and are dependent on relatives or public transport. Especially in rural areas, the accessibility of public transport is often limited. Demand responsive transportation has occasionally been...
Demand Responsive Transport (DRT) systems are often discussed to expand public transport in rural areas, where conventional buses are often used below capacity. DRT systems can particularly improve the mobility situation for less mobile people or other people who depend on public transport and ultimately prevent them from social exclusion. This pap...
This paper analyzes in a large-scale field experiment (N = 1425) whether gift vouchers stimulate the use of a demand responsive transportation (DRT) system. This scenario is compared to a situation where customers receive environmental certificates, which report the saved carbon dioxide as a consequence of the bus ride. In our two treatments, the g...
Globally, housing markets in urban areas have seen significant increase in prices over the past years. These developments are of relevance for the local population as well as social processes that underline the urban cohabitation. Increasing income inequality can impede social mobility, economic opportunities and lead to rising social segregation....
In this article, an abstract framework for annual averaged wind power output generation prediction of wind turbines is presented which is heavily based on large wind speed data sets and power curve data of wind turbines due to the rising interest in wind energy as one main future renewable energy source. As combinations of arbitrary power curve mod...
COVID-19 has spread rapidly around the globe. While there has been a slow down of the spread in some countries, e.g., in China, the African continent is still at the beginning of a potentially wide spread of the virus. Owing to its economic strength and imbalances, South Africa is of particular relevance with regard to the drastic measures to preve...
This chapter considers the challenges and solutions for public transport in low population density areas from an economic perspective. The lower demand density causes economic challenges for providing public transport due to relatively low revenues and cost recovery compared to public transport provision in urban areas. The on-going urbanization ma...
In this paper, we extend existing population growth models and propose a model based on a nonlinear cubic differential equation that reveals itself as a special subclass of Abel differential equations of first kind. We first summarize properties of the time-continuous problem formulation. We state the boundedness, global existence, and uniqueness o...
Tuberculosis (TB) is the 10th leading cause of death worldwide, and since 2007 it has been the main cause of death from a single infectious agent, ranking above HIV/AIDS. The current COVID-19 is a pandemic which caused many deaths around the world. The danger is not only a coinfection as observed for TB and HIV for a long time, but that both TB and...
The future dynamics of the Corona Virus Disease 2019 (COVID-19) outbreak in African countries is largely unclear. Simultaneously, required strengths of intervention measures are strongly debated because containing COVID-19 in favor of the weak health care system largely conflicts with socio-economic hardships. Here we analyze the impact of interven...
Background: COVID-19 has spread from China across Europe and the United States and has become a global pandemic. In countries of the Global South, due to often weaker socioeconomic options and health care systems, effective local countermeasures remain debated.
Methods: We combine large-scale socioeconomic and traffic survey data with detailed agen...
Zusammenfassung
Das Minibustaxi ist eines der wichtigsten Mobilitätsangebote in Südafrika. Allerdings sind Informationen, wie Fahrpläne oder -zeiten, aufgrund der hohen Flexibilität gar nicht oder nur selten verfügbar. Die damit einhergehenden Ineffizienzen, auch im Hinblick auf eine Abstimmung mit anderen Mobilitätsangeboten, können ohne Dokumenta...
Disruptive developments in automated driving systems, new powertrain concepts and digital mobility are shaping changes in the way people move in rural and urban areas. In combination with these technical potentials, novel mobility concepts as for instance demand responsive transportation (DRT) can improve the everyday mobility of people in terms of...
In this paper, the technical requirements to perform a cost-benefit analysis of a Demand Responsive Transport (DRT) service with the traffic simulation software MATSim are elaborated in order to achieve the long-term goal of assessing the introduction of a DRT service in G\"ottingen and the surrounding area. The aim was to determine if the software...
The emergence of new flexible passenger transport services enabled by technological advancements can have substantial impacts on efficiency and sustainability of public transport systems. Socio-economic appraisal methods of transport investments have developed during last decades, and especially CBA is proven to provide robust method for ranking al...
Rural regions in industrialised countries are facing problems in public transport (PT) provision against the backdrop of demographic change, urbanisation and austerity policies. However, innovative mobility concepts evolve under technological developments. Demand responsive transport (DRT) has been identified in research to meet the challenges and...
Since Kermack and McKendrick have introduced their famous epidemiological SIR model in 1927, mathematical epidemiology has grown as an interdisciplinary research discipline including knowledge from biology, computer science, or mathematics. Due to current threatening epidemics such as COVID-19, this interest is continuously rising. As our main goal...
Since Kermack and McKendrick have introduced their famous epidemiological SIR model in 1927, mathematical epidemiology has grown as an interdisciplinary research discipline including knowledge from biology, computer science or mathematics. Due to current threatening epidemics such as COVID-19, this interest is continuously rising. As our main goal,...
Since age and sex play an important role in transmission of diseases, we propose a SIR (susceptible-infectious-recovered) model for short-term predictions where the population is divided into subgroups based on both factors without taking into account vital dynamics. After stating our model and its underlining assumptions, we analyze its qualitativ...
Wind energy represents an important future energy source due to rising global interest in renewable energies. For this reason, power output prediction of wind turbines is a prominent task for supporting decisions regarding future sites. The aim of this study is therefore the development of a general framework for estimating annual averaged power ou...
The following paper examines the determinants of transport mode choice for trips in the Metropolitan Area of the Mexican Valley. Using a data set from the Mexican household travel survey (Encuesta Origen - Destino) conducted in 2017 and multinomial logistic regression, the influence of transportation supply, spatial characteristics and socio-econom...
For many emerging and developing countries, urbanization and demographic changes require a remodelling of transportation systems and networks. Paratransit, with its demand responsive characteristics of being fully flexible, often represents the backbone of the transport sector while being an informal and, therefore, fairly unorganised system with l...
In this article, we reexamine properties of maximum log-likelihood parameter estimation for two-parameter Weibull distributions which have been applied in many different sciences. Besides closed form expressions for the mean and the variance of Weibull distributions, finding reasons for this popularity regarding its use in maximum log-likelihood pa...
This article examines the relationship between offshore wind power generation and the electricity price on the European Energy Exchange (EEX) in Germany. With the help of a GARCH model we show in an integrated approach the influence of offshore wind energy on the level and volatility of the electricity price.The results show that offshore wind ener...
The pandemic outbreak of COVID-19 threatens people worldwide. Politicians around the globe have to balance different interests. Accordingly, they make decisions which heavily impact our daily life or even curtail fundamental rights. They consequently base their judgements on advices from scientists. For these reasons, many epidemiological models ha...
The future dynamics of the Corona Virus Disease 2019 (COVID-19) outbreak in Africa is largely unclear. Simultaneously, required strengths of intervention measures are strongly debated because containing COVID-19 in favor of the weak health care system largely conflicts with socio-economic hardships. Here we analyze the impact of interventions on ou...
One Sentence Summary: Regional agent-based scenario simulations of the COVID-19 outbreak in South Africa suggest that countermeasures in many countries of the Global South are required to be especially rapid and severe to not overload the capacity set by locally available intensive care units.
COVID-19 has spread from China across Europe and the United States and has become a global pandemic. In countries of the Global South, due to often weaker socioeconomic options and health care systems, effective local countermeasures remain debated. We combine large-scale socioeconomic and traffic survey data with detailed agent-based simulations o...
Using online survey data conducted during a pilot phase of the “EcoBus” project, one of the largest true door-to-door demand responsive transport (DRT) field experiments in rural areas, this paper investigates the willingness to pay for different modes of transport. It is assumed that the willingness to pay is affected by parameters favourable for...
The effects of demographic change and the lack of acceptance represent some of the main problems for the public transport infrastructure in rural areas. As a consequence, the development of new transport service options becomes especially relevant for rural communities. The Max-Planck-Institute for Dynamics and Self-Organization developed a new for...
We consider a system of nonlinear first-order differential equations proposed to describe Ca 2+-levels in renal vascular smooth muscle cells. Initially, we present the model and its assumptions. We next investigate an approach to local solvability by Peano's Theorem. Further, we prove non-negativity of the system's possible solutions and we especia...
Zusammenfassung
Der Ausbau der Windenergie geht mit zunehmenden Akzeptanzproblemen und unterschiedlichen Flächennutzungskonflikten einher. Diese ergeben sich maßgeblich aufgrund der großen visuellen und akustischen Signatur von horizontalen Windenergieanlagen und dem großen Flächenbedarf von Windparks. Gegenwärtig werden Untersuchungen zu einem Anl...
Die Infrastrukturen ländlicher Räume sind im Vergleich zu denen städtischer Gebiete geringer ausgebaut. Das hat nicht nur Auswirkungen für die Bevölkerung, sondern auch auf die gesamtgesellschaftlich-wirtschaftliche Ebene. Für die Gesellschaft ist es wichtig, die Verkehrs- und Bildungsinfrastrukturen ländlicher Räume für junge Menschen attraktiv zu...