RESEARCH TOPICS
Resilience of Ecological Network
in Wetlandscape
Wetlands distributed in a large landscape play a critical role in providing various ecosystem services including the provision of ecological habitats, hydrologic controls, and biogeochemical processes. These services are, however, also controlled by hydro-climatic and geological conditions and dispersal pattern of inhabiting species. We are interested in various dispersal models to allow dispersal strategies between habitats. Implications of modeling ecological networks will provide a new decision-making process, especially for conservation purposes.
Kim, Bin (PhD student)
Generating ecological networks using dispersal models (Left: threshold; middle: exponential kernel; right: heavy-tailed model)
Topological analysis of urban water network
For the provision of a reliable supply of water services, water distribution network should be designed and managed to cope with various threats (e.g., disasters). Due to physical properties of this kind of infrastructure, we can view it as a network (or graph) to apply complex system network theory. However, a primal network has limitations to analyze network topology because of spatial features of the network. We aim to develop a dual method to enable getting a deeper insight and more meaningful analytical results from this network. This newly obtained information will be helpful for improving the resilience of infrastructures as complex networks.
Son, Jaewoo (M.S. 2019)
Fig 1. Analysis of water distribution network topology, Geojedo Island, South Korea.
Fig 2. Water distribution system, Jeon-ju city, South Korea.
Water Cycle Sustainability in Megacities
Groundwater has been threatened by various pressures, therefore, sustainable groundwater management is necessary. By compiling the 5856 indicator results of the City Blueprint Approach (CBA) from 122 cities and analyzing the correlation between these indicators, we constructed City Blueprint networks (CBN) by using a complex network modeling approach for three groups of cities: all 122 cities, 40 coastal, and 82 non-coastal cities.
By combining the results of network analysis and CB assessment of the two cities, we could identify the indicators that are potentially at risk regarding coastal groundwater. We propose the CBN as a novel approach to unveil underestimated or hidden factors related to the target system (e.g., groundwater), which allows extensive options for sustainable groundwater management.
City Blueprint Approach
Topology and Resilience of Socio-technical Networks
We are interested in topology and its relation to the resilience of various networked infrastructures such as power grids. As a case study, we have analyzed Korean power grid (KPG) providing another empirical evidence of power grid topology. We identify node degree distribution, efficiency and clustering coefficient, etc. We also do the analysis to test error and attack tolerance of the networks using various scenarios (e.g., intentional vs. random attacks, cascading failures).
For more details, see our recent publication in Physica A
In addition to viewing infrastructure as a solely technicial network, we view it as an engineered complex system coupled by social and technical system. The logic underlying this is by recognizing how well a system recovers from failures depends on policies and protocols for human and organizational coordination that must be considered alongside technological analyses.
Here is our another recent publication in COMPEXITY.
Map of Korean power grid
(Source: Eisenberg et al. 2018)