Displaying 10 of 136 results for "Niklas Hase" clear search
The big picture question driving my research is how do complex systems of interactions among individuals / agents result in emergent properties and how do those emergent properties feedback to affect individual / agent decisions. I have explored this big picture question in a number of different contexts including the evolution of cooperation, suburban sprawl, traffic patterns, financial systems, land-use and land-change in urban systems, and most recently social media. For all of these explorations, I employ the tools of complex systems, most importantly agent-based modeling.
My current research focus is on understanding the dynamics of social media, examining how concepts like information, authority, influence and trust diffuse in these new media formats. This allows us to ask questions such as who do users trust to provide them with the information that they want? Which entities have the greatest influence on social media users? How do fads and fashions arise in social media? What happens when time is critical to the diffusion process such as an in a natural disaster? I have employed agent-based modeling, machine learning, geographic information systems, and network analysis to understand and start to answer these questions.
My primary research interests lie at the intersection of two fields: evolutionary computation and multi-agent systems. I am specifically interested in how evolutionary search algorithms can be used to help people understand and analyze agent-based models of complex systems (e.g., flocking birds, traffic jams, or how information diffuses across social networks). My secondary research interests broadly span the areas of artificial life, multi-agent robotics, cognitive/learning science, design of multi-agent modeling environments. I enjoy interdisciplinary research, and in pursuit of the aforementioned topics, I have been involved in application areas from archeology to zoology, from linguistics to marketing, and from urban growth patterns to materials science. I am also very interested in creative approaches to computer science and complex systems education, and have published work on the use of multi-agent simulation as a vehicle for introducing students to computer science.
It is my philosophy that theoretical research should be inspired by real-world problems, and conversely, that theoretical results should inform and enhance practice in the field. Accordingly, I view tool building as a vital practice that is complementary to theoretical and methodological research. Throughout my own work I have contributed to the research community by developing several practical software tools, including BehaviorSearch (http://www.behaviorsearch.org/)
Sudhira’s research has been primarily on urban land-use and land cover change studies exploring their consequences on environmental sustainability and understanding their inter-relationship with transportation. His broader research addresses the evolution and growth of towns and cities invoking complexity sciences, understanding planning practices and studying the effect of varied governance structures.
I have a special interest in food security, agriculture, climate change, and human - ecosystem interactions. My PhD research focused on developing site-specific strategies for enhancing food production by linking process-based models and empirical models with crop production drivers in Kenya. I am advancing the ideas from my doctorate research to exploring the potential of process-based models coupled with climate data and human decisions at agricultural landscapes for food systems analysis
Social network analysis has an especially long tradition in the social science. In recent years, a dramatically increased visibility of SNA, however, is owed to statistical physicists. Among many, Barabasi-Albert model (BA model) has attracted particular attention because of its mathematical properties (i.e., obeying power-law distribution) and its appearance in a diverse range of social phenomena. BA model assumes that nodes with more links (i.e., “popular nodes”) are more likely to be connected when new nodes entered a system. However, significant deviations from BA model have been reported in many social networks. Although numerous variants of BA model are developed, they still share the key assumption that nodes with more links were more likely to be connected. I think this line of research is problematic since it assumes all nodes possess the same preference and overlooks the potential impacts of agent heterogeneity on network formation. When joining a real social network, people are not only driven by instrumental calculation of connecting with the popular, but also motivated by intrinsic affection of joining the like. The impact of this mixed preferential attachment is particularly consequential on formation of social networks. I propose an integrative agent-based model of heterogeneous attachment encompassing both instrumental calculation and intrinsic similarity. Particularly, it emphasizes the way in which agent heterogeneity affects social network formation. This integrative approach can strongly advance our understanding about the formation of various networks.
My general research interest is on modeling of complex natural and human systems systems. Specifically, I am interested in modeling agricultural production systems, that blends the complexity, multiplicity of scales and feedbacks of biophysical interactions in natural ecosystems with the additional intricacies of human decision-making. During last years I have coordinated the development and evaluation of an agent-based of agricultural production systems in the Argentinean Pampas.
I am a University Academic Fellow (UAF) in the School of Geography at the University of Leeds. My research areas are agent-based modelling, decision making in complex systems, AI and multi-agent systems, urban analytics and housing markets. I obtained PhD in Economics from Iowa State University under supervisor Prof. Leigh Tesfatsion in 2014. I worked as a researcher at the James Hutton Institute in Aberdeen, Scotland between 2014 and 2019. I joined the University of Leeds as a UAF of Urban Analytics in 2019. I am originally from Shanghai, China.
My main research areas are agent-based modelling, urban analytics and complex decision making enabled by AI. I am interested in the bottom-up transition of complex urban systems under major socio-economic and environmental shocks, such as climate change and the fourth industrial revolution. I want to understand how cities as self-organised complex systems respond to external shocks and evolve under a constantly changing environment. In the past, I have looked at various aspects of urban systems, including the housing market, the labour market, transport and energy system. I am also interested in decision making in complex systems. For example, I have studied the decision to become a vegetarian/vegan under social influence. I have also looked at global food trade in a complex trade network and the resulting food and nutrition security. Recently, I am interested in applying AI algorithms especially reinforcement learning in multi-agent systems, including applications of AI in urban adaptation to climate change, housing market dynamics and criminal behaviour in an urban system.
I am Professor in Computational Resilience Economics at the University of Twente (the Netherlands), which I joined in 2010. In September 2017 I also joined University of Technology Sydney (Australia) as Professor of Computational Economic Modeling working with spatial simulation models to study socioeconomic impacts of disasters and emergence of resilience across scales. I was honored to be elected as a Member of the De Jonge Akademie of the Royal Dutch Academy of Sciences (DJA/ KNAW in 2016) and of Social Sciences Council (SWR/KNAW in 2017). From 2009 to 2015 I have been working part-time as an economist at Deltares – the leading Dutch knowledge institute in the field of water management – specializing in economics of climate change, with focus on floods and droughts management.
I am interested in the feedbacks between policies and aggregated outcomes of individual decisions in the context of spatial and environmental policy-making. The issue of social interactions and information diffusion through networks to affect economic behavior is highly relevant here. My research line focuses on exploring how behavioral changes at micro level may lead to critical transitions (tipping points/regime shifts) on macro level in complex adaptive human-environment systems in application to climate change economics. I use agent-based modelling (ABM) combined with social science methods of behavioral data collection on individual decisions and social networks. This research line has been distinguished by the NWO VENI and ERC Starting grants and the Early Career Excellence award of the International Environmental Modeling Society (iEMSs). In 2018 I was invited to serve as the Associate Editor of the Environmental Modelling & Software journal, where I have been a regular Member of the Editorial Board since 2013.
Community assembly after intervention by coral transplantation
The potential of transplantation of scleractinian corals in restoring degraded reefs has been widely recognized. Levels of success of coral transplantation have been highly variable due to variable environmental conditions and interactions with other reef organisms. The community structure of the area being restored is an emergent outcome of the interaction of its components as well as of processes at the local level. Understanding the
coral reef as a complex adaptive system is essential in understanding how patterns emerge from processes at local scales. Data from a coral transplantation experiment will be used to develop an individual-based model of coral community development. The objectives of the model are to develop an understanding of assembly rules, predict trajectories and discover unknown properties in the development of coral reef communities in the context of reef restoration. Simulation experiments will be conducted to derive insights on community trajectories under different disturbance regimes as well as initial transplantation configurations. The model may also serve as a decision-support tool for reef restoration.
performance of urban water service provision, high levels of inequities and inefficiency persist. In terms of water distribution and cost, these undesirable patterns have a high impact on peri-urban areas usually populated by marginalized and poor populations. The high levels of Non-Revenue Water (NRW), together with the existence of corrupt practices and mismanagement of water utilities, remain a highly controversial issue.
This situation confronts rent-seeking theory directly, explaining the performance-corruption relationship (Repetto, 1986). The presumption is that low performance in water supply service provision results from corruption because rent-seeking occurs. Hence, the implementation of performance-oriented reforms in the water supply sector, such as regulation or private sector participation, will reduce corruption, increasing the efficiency of water service provision. Nevertheless, latest evidence shows that “key elements of good political governance have a positive effect on the access to water services in developing countries. In turn, private sector participation has little influence other than increasing internal efficiency of water providers” (Krausse, 2009).
Indeed the relation between governance, corruption and performance seems to be more complex than theory wants to acknowledge. It must be reviewed further than a simple cause-effect relationship. It appears that poor management of water utilities, evidenced by high levels of NRW, justifies new investments. Such practices can be encouraged by an “opportunistic management”, whilst at the same time maintaining an influential “hydrocratic elite” in the sphere of water control.
The present research proposal aims to understand the relation between mismanagement and corruption of water control practices in water supply service provision. The research examines how this relationship affects the performance of water service provision and relates to water supply governance models at municipal peri-urban level in three African countries.
To understand the mismanagement-corruption relationship, we look at different case studies of water supply service provision in Senegal, Ghana and Kenya. Each case represents a different governance model in terms of management practices, institutional and organizational settings, and the actors in place, which affects the performance of water service provision in terms of allocative efficiency and access to water (equity). Whether regulation, decentralization and private sector participation constitute possible ways to reduce corruption is examined in the context of water sector reform.
In a second step, we propose a theoretical model based on Agent Based Modelling (ABM) (Pahl-Wostl, 2007) to reproduce complex social networks under a Socio-Ecological System (SES) framework approach. The model will allow us to test whether collaborative governance in the form of collective action in a participatory and negotiated decision-making process for water control, can reduce corruption and increase performance.
The present research benefits from the project “Transparency and Integrity in Service Delivery in Sub-Saharan Africa”. This project, carried out by Transparency International (TI) in 8 Sub-Saharan countries, aims to increase access to education, health and water by improving transparency and integrity in basic service delivery. The proposal retains focus on Senegal, Ghana and Kenya in the water sector.
Key words: water control, mismanagement, corruption, performance, collaborative governance, modelling, collective action, negotiation, participation
Displaying 10 of 136 results for "Niklas Hase" clear search