This is a page about what Zhenhua Zhang is doing now.

Current work for research:

Flow Mapping


Flows, such as population migration, disease spread, and network/traffic, naturally form a weighed location-to-location graph. Such kind of geographic location based graphs are often very large. The problem how to draw these large graphs with a great amount of nodes and edges nicely to help to analyse and understand movements better is challenging.


original algorithm enhanced by zhenhua
original algorithm enhanced by zhenhua

* enhance Phan-Tree algorithm

  • do edge routine as soon as the graph comes out of the root(the original algorithm ignores edge routine of the out edge/cluster of root)
  • do more complete intersection check to reduce clutter of graph
  • try to introduce some other parameters to participate the node clustering, currently only use the distance between locations
  • invoke heuristic algorithm to draw graphs
  • read papers about draw pictures with heuristic algorithm like Simulated Annealing, Genetic algorithm
  • try to apply classic heuristic algorithm or enhancing version of heuristic algorithm to draw flow mapping graphs to make the clutter as few as possible

Current work for project:

Collaboration Environment for CIGI

Yongzheng and Zhenhua are now trying to build collaboration System for CIGI with HUBzero opensource. Currently, we have finished the configuration of the original HUBzero version, added social network capability to the system homepage including updating and receiving messages from twitter and facebook, revised some bugs and errors of original opensource, deployed it on the virtual machine with IP I am still doing the test work and some development work with Yongzheng and Julie.

cigi collaboration