My picture
Location: 2231 EB-II, Centennial Campus, Raleigh, NC
Email: p-hsiao@ncsu.edu (remove dash)
Tel: 919-513-4663

My name is Ping-Lin Hsiao. I go by Joe Hsiao.
I am a currently a 3rd-year Computer Science Ph.D Student working in Knowledge Discovery Lab (KDL) with Chris Healey at NCSU.
My research interests are visualilzation and computer graphics. Here is my resume.


Research

document clustering   Document Clustering  (pdf)

Document clustering is an approach to organize unstructured text information into meaningful groups. It can be applied to documents in a database to improve performance in information retrieval, or it can be used to organize query results from the web or other types of large, heterogeneous text collections. In this report, we describe a new clustering algorithm to categorize and spatially cluster text documents. We employ TF-IDF and term co-occurrence to measure document-to-document similarities. Next, a modified minimum spanning tree algorithm is used to cluster similar documents. Finally, we apply multidimensional scaling on the clusters to represent them as spatial clusters on a 2D plane. The system is tested with sets of articles generated by an Internet search engine for certain topic areas. Our result shows that the system is capable of distinguishing different topics and producing recognizable and informative clusters.


Master Thesis

Visualization for Combinatorial Auctions   Visualization for Combinatorial Auctions  (pdf)

We propose a new 2D scheme for concisely visualizing combinatorial datasets. The visualization displays concentric rings composed of arcs, with each base element subset mapped to a single arc. Equal sized subsets are placed on a common ring. The outermost ring contains subsets of size one. Interior rings contain larger subsets. The rings are positioned to try to overlap common base elements as much as possible. This allows viewers to search a local region of the visualization to study the behavior of a given base element (i.e., a given item offered within the combinatorial auction). Additional visual features, including motion, color, and texture are applied to represent auction attributes like the identity of a bidder, which bids win in a particular stage of the auction, and so on. Our visualizations provide viewers with an efficient and effective way to observe how an auction progresses.


Project

Flow Visualization   Flow Visualization  (exe)

The application takes as input a grid of vector data, and maps those vectors to a grid on the screen. Each coordinate within the grid has two properties: direction and speed, which are inherited from the input vector. The grid is invisible and works like an underlying magnetic field. We chooses a set of seed places on the screen. Each seed place spits out a sequence of bitmaps constantly. These bitmaps travel to different directions with varied speeds, reflecting on which vector the bitmap is on at the current moment. If a bitmap moves onto a new vector, its direction and speed would be changed by the new vector. With enough bitmaps, their movement will reveal the flows of the whole grid of underlying vectors. All bitmaps have a same life cycle. Bitmaps become transparent when they approach the end of life, and disappear at the end. This avoids the screen to be overwhelmed by too many bitmaps. Users can also load their own bitmaps.