A Regularized Graph Layout Framework for Dynamic Network Visualization

Many real-world networks, including social and information networks, are dynamic structures that evolve over time. Such dynamic networks are typically visualized using a sequence of static graph layouts. In addition to providing a visual representation of the network structure at each time step, the sequence should preserve the mental map between layouts of consecutive time steps to allow a human to interpret the temporal evolution of the network. In this paper, we propose a framework for dynamic network visualization in the on-line setting where only present and past graph snapshots are available to create the present layout. The proposed framework creates regularized graph layouts by augmenting the cost function of a static graph layout algorithm with a grouping penalty, which discourages nodes from deviating too far from other nodes belonging to the same group, and a temporal penalty, which discourages large node movements between consecutive time steps. The penalties increase the stability of the layout sequence, thus preserving the mental map. We introduce two dynamic layout algorithms within the proposed framework, namely dynamic multidimensional scaling (DMDS) and dynamic graph Laplacian layout (DGLL). We apply these algorithms on several data sets to illustrate the importance of both grouping and temporal regularization for producing interpretable visualizations of dynamic networks.Comment: To appear in Data Mining and Knowledge Discovery, supporting material (animations and MATLAB toolbox) available at http://tbayes.eecs.umich.edu/xukevin/visualization_dmkd_201

Using interactive and multi-touch technology to support decision making in multidisciplinary team meetings

In multidisciplinary team (MDT) meetings for colorectal and liver cancer, each patient case is reviewed while evidence, including digital image scans such as MRI and PET/CT, is presented by clinicians. Currently these images are projected onto a wall, limiting clinician interaction. While multi-touch and interactive tabletops have been used to enhance collaboration in various scenarios, some aspects such as image quality and touch resolution need to be evaluated in this particular scenario. In this paper we present the results of work conducted to test the suitability of using a DiamondTouch tabletop, a multi-touch and multi-user surface, in MDT meetings to enhance clinician interaction. © 2010 IEEE

Lowering the barriers to cancer imaging

There are various issues that limit the development and deployment of new software solutions in cancer image analysis research. In this paper we discuss some of these and propose a framework design based on cloud computing concepts, Microsoft technologies, existing middleware and imaging toolkits. Furthermore, we address some of these issues by introducing collaborative visual tools for visual input data and multi-user interactions. © 2008 IEEE

Sharing and reusing cancer image segmentation algorithms using scientific workflows: Pros and cons

Image analysis researchers would benefit considerably by sharing and reusing image processing algorithms. We consider some of the issues that researchers face in trying to provide algorithms in a shareable and reusable form illustrating our approach in the context of medical imaging needs and workflow for colorectal cancer. We consider the use of workflow as a model for developing and reusing components of medical imaging and specifically we consider a solution built using .Net and Windows Workflow Foundation. © 2009 IEEE

From Data Analysis and Visualization to Causality Discovery.

As data becomes invisible, emerging technologies can help human analysts and decision makers understand, model, and visualize causal relationships. © 2011 IEEE

Visualizing Cardiovascular Magnetic resonance (CMR) imagery: challenges and opportunities

Cardiovascular Magnetic Resonance (CMR) imaging is an essential technique for measuring regional myocardial function. However, it is a time-consuming and cognitively demanding task to interpret, identify and compare various motion characteristics based on watching CMR imagery. In this work, we focus on the problems of visualising imagery resulting from 2D myocardial tagging in CMR. In particular we provide an overview of the current state of the art of relevant visualization techniques, and a discussion on why the problem is difficult from a perceptual perspective. Finally, we introduce a proof-of-concept multilayered visualization user interface for visualizing CMR data using multiple derived attributes encoded into multivariate glyphs. An initial evaluation of the system by clinicians suggested a great potential for this visualisation technology to become a clinical practice in the future

Visual multiplexing

The majority of display devices used in visualization are 2D displays. Inevitably, it is often necessary to overlay one piece of visual information on top of another, especially in applications such as multi-field visualization and geo-spatial information visualization. In this paper, we present a conceptual framework for studying the mechanisms for overlaying multiple pieces of visual information while allowing users to recover occluded information. We adopt the term 'multiplexing' from tele- and data communication to encompass all such overlapping mechanisms. We establish 10 categories of visual multiplexing mechanisms. We draw support evidence from both perception literature and existing works in visualization to support this conceptual framework. We examine the relationships between multiplexing and information theoretic measures. This new conceptual categorization provides the much-needed theory of visualization with an integral component. © 2014 The Eurographics Association and John Wiley and Sons Ltd. Published by John Wiley and Sons Ltd

Visual multiplexing

The majority of display devices used in visualization are 2D displays. Inevitably, it is often necessary to overlay one piece of visual information on top of another, especially in applications such as multi-field visualization and geo-spatial information visualization. In this paper, we present a conceptual framework for studying the mechanisms for overlaying multiple pieces of visual information while allowing users to recover occluded information. We adopt the term 'multiplexing' from tele- and data communication to encompass all such overlapping mechanisms. We establish 10 categories of visual multiplexing mechanisms. We draw support evidence from both perception literature and existing works in visualization to support this conceptual framework. We examine the relationships between multiplexing and information theoretic measures. This new conceptual categorization provides the much-needed theory of visualization with an integral component. © 2014 The Eurographics Association and John Wiley and Sons Ltd. Published by John Wiley and Sons Ltd

Visualizing Cardiovascular Magnetic resonance (CMR) imagery: challenges and opportunities

Cardiovascular Magnetic Resonance (CMR) imaging is an essential technique for measuring regional myocardial function. However, it is a time-consuming and cognitively demanding task to interpret, identify and compare various motion characteristics based on watching CMR imagery. In this work, we focus on the problems of visualising imagery resulting from 2D myocardial tagging in CMR. In particular we provide an overview of the current state of the art of relevant visualization techniques, and a discussion on why the problem is difficult from a perceptual perspective. Finally, we introduce a proof-of-concept multilayered visualization user interface for visualizing CMR data using multiple derived attributes encoded into multivariate glyphs. An initial evaluation of the system by clinicians suggested a great potential for this visualisation technology to become a clinical practice in the future