26 research outputs found
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
Management of pulmonary mucormycosis after orthotopic heart transplant: A case series
Invasive pulmonary mucormycosis is a potentially fatal infection that can occur in immunosuppressed patients such as those who have undergone orthotopic heart transplant (OHT). High-dose intravenous antifungal agents, including amphotericin B, are generally accepted as the first-line medical treatment, with prompt surgical resection of lesions if feasible. The body of evidence guiding treatment decisions, however, is sparse, particularly regarding adjustment of immunosuppression during acute infection and long-term recovery. We present 2 cases of patients with pulmonary mucormycosis occurring within the first 6 months after OHT, both of whom successfully recovered after appropriate medical and surgical treatment, and we highlight differences in immunosuppression management strategies for this life-threatening condition
Designing for Light-Weight Collaboration: The Case of Interactive Citizens’ Advisory Services
This paper reports on the design of a collaborative system to support citizens' advisory services. Recent research on the adoption of collaborative technologies indicates that: a) successful collaborative technologies diffuse from the private sector to the business sector and not vice versa, b) collaborative processes evolve and therefore cannot be prestructured in detail, and c) creative collaboration can be characterized as creating and sharing mental models. We demonstrate how these insights informed our design of a citizens' advisory system and provide data from an evaluation in a German city. Implications for the design of our collaborative system are offered