Abstract of Invited Talks
 
Jennifer Seberry (Wollongong)
"Privacy Piracy"
We will explore the effect of Privacy Legislation and Hacktivism on the privacy of individuals in the Global Village.
 
Xuemin Lin (UNSW)
" Graph Partition Based Multi-Way Spatial Joins"
In this paper, we investigate the problem of efficiently computing a multi-way spatial join without spatial indexes. We propose a novel and effective filtering algorithm based on a two  phase partitioning technique.
To avoid missing hits due to an inherent difficulty in multi-way spatial joins, we propose to firstly partition a join graph into sub-graphs whenever necessary. In the second phase, we partition the spatial data sets; and then the sub-joins will be executed simultaneously in each partition to minimize the I/O costs. Finally, a multi-way relational join will be applied to merge together the sub-join results. Our experiment results demonstrated the effectiveness and efficiency of the proposed algorithm.
 
Mao Lin Huang (UTS)
"Information Visualization for B2C e-Commerce"
This paper describes the development of a 2D interactive visual interface for navigating online product catalogs that are commonly used for B2C e-commerce. We introduce an e-commerce framework for Visual Online Shops that use a 2D dynamic graph visualization as an interface allowing buyers to interactively navigate through the large product hierarchies with a sense of information space.
We discuss applications of several dynamic visualization techniques, such as Image-Map and OFDAV browser that can be used to assist buyers in navigating large product information spaces dynamically and help them in selecting suitable products through the mouse clicks of appropriate
graphical nodes in the visualization. The prototypes are written in Java, JavaScript, PHP and MySQL that simulate the online shopping experiences. These techniques are applicable to any e-commerce online purchasing application.
 
Richard Webber (Newcastle)
"Interacting with 3D Graph Drawings"
While three-dimensional graph drawing has been a hot-topic of research for some time, little attention has been paid to the ways in which we view the resulting drawings. This talk will provide an outline of the techniques available for presenting the three-dimensional graph drawings. In particular, it will concentrate on viewpoint selection, and will review the results to date in this area.
 
Hugo do Nascimento (Usyd)
"An Interactive System for Drawing Directed Graphs"
In this talk we investigates an  interactive approach where users can help a system to produce nice
drawings of directed graphs by giving "hints" to graph drawing algorithms. Hints can be three kinds of operations: focus on a specific part of the drawing that needs improvement, insertion of layout constraints, and manual changes of the drawing.  
A system that supports such facilities was built and tested in a pilot study involving human experiments. We believe that the hint-based approach can effectively extend the capabilities of graph drawing tools.
 
Quang Vinh Nguyen (UTS)
"A Space-Optimising Tree Visualization"
The project investigates on a new technique for visualising and manipulating information especially for very large hierarchies (more than ten thousand nodes). Tree-maps (Johnson & Schneiderman, 91), which claims 100% space efficiency, does not shows well relationship and structure of information. Traditional tree layout techniques; however, waste a lot of space and are not adequate for visualising large hierarchies (more then a thousand nodes). The aim of this technique is to optimise available displaying space while visualizes well relationships of the structures.
 
Qing Zhang (UNSW)
"Error Minimization for Approximate Aggregation by Histograms"
Histogram techniques are widely used in commercial database management systems for an estimation of query results. Recently, they have been also used to approximately processing database queries, especially aggregation queries. Existing research results in this area have been focused on constructing a histogram to approximately represent, as accurate as possible on an intuitive base, the original data frequencies. 
In this talk, we will propose a novel data partition model to construct a histogram to minimize   aggregation processing errors. Our new model suits for any query patterns. Based on the new model, we have developed an efficient algorithm to construct "optimal" histograms to minimize   aggregation processing errors. Our experiment results showed that the new histogram construction techniques lead to more accurate results than those by existing histogram techniques, and also out-perform the existing wavelet techniques.
 
Kim Marriott (Monash)
"Supporting Adaptive, Interactive Diagrams for the Web"
People use diagrams all of the time, ranging from UML notations to subway maps. With the advent of SVG, the new W3C standard for vector graphics, the use of diagrams on the web is certain to increase. However, this new medium forces a radical reappraisal of what we understand a diagram to be. We need to move from the print-media based view of a diagram as a static collection of markings on a fixed size piece of paper, to one in which a diagram is dynamic, adapting its layout and level of detail to the current context in order to best utilise the viewing device capabilities, such as screen size and so as to take into account the viewer's requirements, such as area of interest, native language or need for large fonts. As well, we need support for interactive exploration of diagrams and support for retrieval of diagrams based on their semantic content and surrounding context. Of course, we also need authoring tools to build such intelligent, interactive diagrams. And these need to support both construction by humans and automatic generation and layout. In this talk I will argue that constraint-based graphics and grammar-based diagram understanding provide a good basis for providing these capabilities. In particular, I will describe a proposed extension to SVG which uses one-way constraints to provide adaptation and interactive exploration and a prototype implementation using Visio.
 
Seokhee Hong (Usyd)
"Survey on Symmetric Graph Drawing"
Symmetry is one of the most important aesthetic criteria that represent the structure and properties of a graph visually. This talk begins with a discussion of the motivations, definitions, and complexity of symmetric graph drawing. It goes on to review certain solved problems in this area, including optimal algorithms for the detection and display of geometric symmetry in planar graphs in two and three dimensions. Then discuss some methods for finding symmetries in general graphs. Finally, some open problems are presented and discussed.
 
Carsten Friedrich (Usyd)
"Force Directed Animation"
Being able to maintain the mental map between changing drawings is a basic challenge for users of dynamic graph visualization systems. Animations, that is smooth transformations from the initial to the target drawings, can significantly help the user in achieving this task. However, not all possible animations are equally suitable, and in particular naive animation methods often do not yield convincing results. In this talk we identify criteria and measures that allow comparison of different animation methods. We further present two animation methods that directly optimise some of those criteria by encoding and simulating them in a force directed system.