Connectivity and community structure in the London bike sharing system. More stories here
A big-data approach to analyzing urban metro ridership in Beijing. More stories here
Modeling of passenger queuing and crowding at a major international train station
Reduction of Black Carbon concentration in West Glasgow after applying intelligent traffic signal control and variable message sign. Negative values indicate reduction (the CARBOTRAF project)
Dr Han's research focuses on developing models and methodologies to deliver insights into the design and management of complex transport systems and to facilitate their implementation and assessment in a real-world environment. This is done by combining modern mobility concepts and technologies with traditional tools of mathematics, statistics, operations research, and scientific computing. His research has advanced the modelling, simulation, and optimization of dynamic, multi-agent, multi-modal, interdependent, complex, and competitive transport systems. These have given rise to efficient and tractable models and algorithms, robust and reliable solutions for real-time decisions, managerial insights into transport systems with quantifiable and validated outcomes, and enhanced understanding of the qualitative behaviour of transport networks pertinent to robustness, resilience, stability, and sustainability. Ke's research is underpinned by the following three pillars.
1. MODELING OF COMPLEX AND DYNAMIC TRANSPORT NETWORKS.
Ke has developed models with varying spatial-temporal resolutions (i.e. microscopic, mesoscopic, and macroscopic) and fidelities (i.e. analytical vs. simulation-based) to accurately and efficiently describe and predict traffic and transport networks. These include, but are not limited to, urban arterial networks, intra-urban and inter-urban transit networks, motorway networks, air traffic networks, and supply chain networks. A key focus has been placed on their computability, i.e. mathematical properties pertinent to the existence, uniqueness and well-posedness of the solutions, as well as robust and efficient algorithms for large-scale simulation and integration with control and optimization procedures.
2. TRANSPORT OPERATION AND TRAFFIC MANAGEMENT.
Building on 1, Dr Han has been designing methodological frameworks for the control and management of network traffic at the levels of strategic planning and real-time operation. He has developed innovative procedures to utilize advanced models and data management paradigms in order to identify and optimize traffic control and management measures. These include traffic signal control, variable message sign, ramp metering, congestion charging, route guidance, information dissemination, etc. The impacts of these measures have been broadened to include not only the social and economic aspects of congestion externality, but also the environmental welfare related to air quality, energy consumption, and public health. This is done through collaboration with colleagues from environmental science, big-data analytics, and smart city.
3. NETWORK SCIENCE AND ENGINEERING.
Using tools developed in 1 and 2, Ke is investigating and assessing the qualitative behaviour of networks with diverse structure, configuration, and functionality. Specifically, he has been studying the network response to natural and man-made disasters with varying degrees of magnitude and severity. This line of research is naturally related to transport network resilience, robustness, stability, and viability. It also sheds lights on network design and infrastructure management. Ke's research in this regard goes beyond the state-of-the-art in network science, and focuses on the inner mechanisms pertaining to demand-supply balance and adaptive agent behaviour. These mechanisms give rise to the macroscopic and collective behaviour of the network in terms of formation, evolution, and self-regulation – a notion now recognized as one aspect of modern complexity science.
- Imperial College – Zhejiang University Exchange Program, "Mitigating urban traffic emissions based on big data in traffic and air quality".
- 7th EU Framework Programme/28786, "CARBOTRAF - A Decision Support System for Reducing CO2 and Black Carbon Emissions by Adaptive Traffic Management"
- US NSF/EFRI-1024707, "A Theory of Complex Transportation Network Design"
- US NSF/CMMI-0900040, "Stochastic Dynamic Game-Theoretic Models of Urban Freight Systems"
- US NSF/CMMI-0824640, "Congestion Option: A Market Solution to Congestion Externalities"
- US MAUTC/PSU-2011-06, "Computational and Data Enabled Analysis for Sustainable Transportation Systems"
College of Civil Aviation, Nanjing University of Aeronautics and Astronautics, Air traffic flow management, 2015
Reducing air pollution with smart transportation, Smart City in the Big Data Era Summit, the Big Data Expo, Guiyang, Guizhou, China, 2017
Real-time traffic management: challenges and solutions, Institute for Transport Studies, University of Leeds, Leeds, UK, 2016
An analytical approach to sustainable transportation network design, Transportation Research Board Doctoral Dissertation Workshop on Transportation Modeling, Washington DC, USA, 2014
Statistical metamodeling of dynamic network loading and application to dynamic traffic assignment, University of New South Wales, Sydney, NSW, Australia, 2016
On the continuum approximation of the on-and-off signal control on dynamic traffic networks, Institut Henri Poincaré, Paris, 2014
The mathematical foundation of dynamic user equilibria, Workshop on ANalysis and COntrol on NETwork (ANCONET), University of Padova, Italy, 2016
Data-driven decision rule approach for real-time traffic management, Transportation Research Board Traffic Flow Theory and Characteristics Committee, ISTTT21 Webinar Series, 2016
On some theoretical and practical aspects of traffic signal control, Southwest Jiaotong University, Chengdu, Sichuan, China, 2015
Optimization of operations in multi-airport systems, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu, China, 2016
Data-driven decision rule approach for real-time traffic management, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu, China, 2016
Dynamic traffic flow on networks (Tutorial), University of Sydney, Sydney, New South Wales, Australia, 2016
Dynamic user equilibrium: A differential game perspective (Tutorial), University of Sydney, Sydney, New South Wales, Australia, 2016
Traffic operation facilitated by telecommunication: Some case studies, Transportation Research Board Chan Wui & Yunyin Rising Star Workshop, USA, 2016
How to publish your research in scientific journals, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu, China, 2016
Optimization of operations in multi-airport systems, Dalian Maritime University, Dalian, Liaoning, China, 2016
Some aspects of real-time traffic control & management, Zhejiang University, Hangzhou, Zhejiang, China, 2016