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Visualization of Graphs with Associated Timeseries Data
"... The most common approach to support analysis of graphs with associated time series data include: overlay of data on graph vertices for one timepoint at a time by manipulating a visual property (e.g. color) of the vertex, along with sliders or some such mechanism to animate the graph for other timepo ..."
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Cited by 18 (3 self)
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The most common approach to support analysis of graphs with associated time series data include: overlay of data on graph vertices for one timepoint at a time by manipulating a visual property (e.g. color) of the vertex, along with sliders or some such mechanism to animate the graph for other timepoints. Alternatively, data from all the timepoints can be overlaid simultaneously by embedding small charts into graph vertices. These graph visualizations may also be linked to other visualizations (e.g., parallel coordinates) using brushing and linking. This paper describes a study performed to evaluate and rank graph+timeseries visualization options based on users’ performance time and accuracy of responses on predefined tasks. The results suggest that overlaying data on graph vertices one timepoint at a time may lead to more accurate performance for tasks involving analysis of a graph at a single timepoint, and comparisons between graph vertices for two distinct timepoints. Overlaying data simultaneously for all the timepoints on graph vertices may lead to more accurate and faster performance for tasks involving searching for outlier vertices displaying different behavior than the rest of the graph vertices for all timepoints. Single views have advantage over multiple views on tasks that require topological information. Also, the number of attributes displayed on nodes has a non trivial influence on accuracy of responses, whereas the number of visualizations affect the performance time.
Mental Map Preserving Graph Drawing Using Simulated Annealing
 Proc. AsiaPacific Symp. Information Visualisation
, 2006
"... Information visualization has attracted much attention in recent years in many fields of science and engineering. In many applications, graphs are ‘dynamic ’ in the sense that changes are constantly applied to a graph to reflect the evolution of the system behaviour represented by the graph. In the ..."
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Information visualization has attracted much attention in recent years in many fields of science and engineering. In many applications, graphs are ‘dynamic ’ in the sense that changes are constantly applied to a graph to reflect the evolution of the system behaviour represented by the graph. In the past, the concept of the socalled “mental map ” has largely been ignored. Users often have to spend a lot of time relearning the redrawn graphs. This paper proposes an effective way to release the user from such kind of a distasteful job by maintaining a high degree of the “mental map ” for general graphs when graphs are redrawn. Our experimental results suggest this new approach to be promising..
Organizing Search Results with a Reference Map
"... (a) reference map (entire database) (b) query hits by relevance and similarity Fig. 1. Maintaining the global organization of subsets in hierarchically clustered document collections. Abstract — We propose a method to highlight query hits in hierarchically clustered collections of interrelated items ..."
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Cited by 8 (0 self)
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(a) reference map (entire database) (b) query hits by relevance and similarity Fig. 1. Maintaining the global organization of subsets in hierarchically clustered document collections. Abstract — We propose a method to highlight query hits in hierarchically clustered collections of interrelated items such as digital libraries or knowledge bases. The method is based on the idea that organizing search results similarly to their arrangement on a fixed reference map facilitates orientation and assessment by preserving a user’s mental map. Here, the reference map is built from an MDS layout of the items in a Voronoi treemap representing their hierarchical clustering, and we use techniques from dynamic graph layout to align query results with the map. The approach is illustrated on an archive of newspaper articles. Index Terms—Search results, mental map, voronoi treemaps, dynamic graph layout, multidimensional scaling, edge bundling. 1
Minimizing crossings in hierarchical digraphs with a hybridized genetic algorithm
 J. Heuristics
, 2006
"... Abstract. Producing clear and intelligible layouts of hierarchical digraphs knows a renewed interest in information visualization. Recent experimental results show that metaheuristics are welladapted methods for this problem. In this paper, we develop a new Hybridized Genetic Algorithm for arc cros ..."
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Cited by 8 (2 self)
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Abstract. Producing clear and intelligible layouts of hierarchical digraphs knows a renewed interest in information visualization. Recent experimental results show that metaheuristics are welladapted methods for this problem. In this paper, we develop a new Hybridized Genetic Algorithm for arc crossing minimization. It follows the basic scheme of a GA with two major differences: problembased crossovers adapted from ordering GAs are combined with a local search strategy based on averaging heuristics. Computational testing was performed on a set of 180 random hierarchical digraphs of standard sizes with various structures. Results show that the Hybridized Genetic Algorithm significantly outperforms Tabu Searchwhich is one of the best known methods for this problem and also a multistart descent except for highly connected graphs.
On the Hardness of OrthogonalOrder Preserving Graph Drawing
, 2009
"... There are several scenarios in which a given drawing of a graph is to be modified subject to preservation constraints. Examples include shape simplification, sketchbased, and dynamic graph layout. While the orthogonal ordering of vertices is a natural and frequently called for preservation constrai ..."
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Cited by 6 (0 self)
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There are several scenarios in which a given drawing of a graph is to be modified subject to preservation constraints. Examples include shape simplification, sketchbased, and dynamic graph layout. While the orthogonal ordering of vertices is a natural and frequently called for preservation constraint, we show that, unfortunately, it results in severe algorithmic difficulties even for the simplest graphs. More precisely, we show that orthogonalorder preserving rectilinear and uniform edge length drawing is NPhard even for paths.
Euler Diagram Transformations
 Graph Transformations & Visual Modelling Techniques, ECEASST
"... Abstract: Euler diagrams are a visual language which are used for purposes such as the presentation of setbased data or as the basis of visual logical languages which can be utilised for software specification and reasoning. Such Euler diagram reasoning systems tend to be defined at an abstract le ..."
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Abstract: Euler diagrams are a visual language which are used for purposes such as the presentation of setbased data or as the basis of visual logical languages which can be utilised for software specification and reasoning. Such Euler diagram reasoning systems tend to be defined at an abstract level, and the concrete level is simply a visualisation of an abstract model, thereby capturing some subset of the usual boolean logic. The visualisation process tends to be divorced from the data transformation process thereby affecting the user’s mental map and reducing the effectiveness of the diagrammatic notation. Furthermore, geometric and topological constraints, called wellformedness conditions, are often placed on the concrete diagrams to try to reduce human comprehension errors, and the effects of these conditions are not modelled in these systems. We view Euler diagrams as a type of graph, where the faces that are present are the key features that convey information and we provide transformations at the dual graph level that correspond to transformations of Euler diagrams, both in terms of editing moves and logical reasoning moves. This original approach gives a corre
MOVIS: A system for Visualizing Distributed Mobile Object Environments
"... This paper presents MOVIS – a system for visualizing mobile object frameworks. In such frameworks, the objects can migrate to remote hosts, along with their state and behavior, while the application is running. An innovative graph–based visualization is used to depict the physical and the logical c ..."
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This paper presents MOVIS – a system for visualizing mobile object frameworks. In such frameworks, the objects can migrate to remote hosts, along with their state and behavior, while the application is running. An innovative graph–based visualization is used to depict the physical and the logical connections in the distributed object network. Scalability is achieved by using a focus+context technique jointly with a usersteered clustering algorithm. In addition, an event synchronization model for mobile objects is presented. The system has been applied to visualizing several mobile object applications. Index Terms – Distributed software visualization, mobile objects, dynamic graph layout 1
InsightBased Studies for Pathway and Microarray Visualization Tools
, 2006
"... Pathway diagrams, similar to the graph diagrams using a nodelink representation, are used by biologists to represent complex interactions at the molecular level in living cells. The recent shift towards dataintensive bioinformatics and systemslevel science has created a strong need for advanced p ..."
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Pathway diagrams, similar to the graph diagrams using a nodelink representation, are used by biologists to represent complex interactions at the molecular level in living cells. The recent shift towards dataintensive bioinformatics and systemslevel science has created a strong need for advanced pathway visualization tools that support exploratory data analysis. User studies suggest that an important requirement for biologists is the need to associate microarray data to pathway diagrams. A design space for visualization tools that allow analysis of microarray data in pathway context was identified for a systematic evaluation of the visualization alternatives. The design space is divided into two dimensions. Dimension 1 is based on the method used to overlay data attributes onto pathway nodes. The three possible approaches are: overlay of data on pathway nodes one data attribute at a time by manipulating a visual property (e.g. color) of the node, along with sliders or some such mechanism to animate the pathway for other timepoints. In another approach data from all the attributes in data can be overlaid simultaneously by embedding small charts (e.g.,
Dynamic graph drawing with a hybridized genetic algorithm
 In ACDM VI
, 2004
"... Automatic graph drawing algorithms, especially those for hierarchical digraphs, have an important place in computeraided design software or more generally in software programs where an efficient visualization tool for complex structure is required. In these cases, aesthetics plays a major role for ..."
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Automatic graph drawing algorithms, especially those for hierarchical digraphs, have an important place in computeraided design software or more generally in software programs where an efficient visualization tool for complex structure is required. In these cases, aesthetics plays a major role for generating readable and understandable layouts. Besides, in an interactive approach, the program must preserve the mental map of the user between time t − 1 and t. In this paper we introduce a dynamic drawing procedure for hierarchical digraph drawing. It tends to minimize arccrossing thanks to a hybridized genetic algorithm. The hybridization consists of a local optimization step based on averaging heuristics and two problembased crossover operators. A stability constraint based on a similarity measure is used to preserve the likeness between the layouts at time t−1 and t. Computational experiments have been done with an adapted random graph generator to simulate the construction process of 90 graphs. They confirm that, because of the actual algorithm, the arc crossing number of the selected layout is close to the best layout found. We show that computation of the similarity measure tends to preserve the likeness between the two layouts. 1
OrthogonalOrdering Constraints make Graph Drawing Hard
, 2010
"... There are several scenarios in which a given drawing of a graph is to be modified subject to preservation constraints. Examples include shape simplification, sketchbased, and dynamic graph layout. While the orthogonal ordering of vertices is a natural and frequently called for preservation constrai ..."
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There are several scenarios in which a given drawing of a graph is to be modified subject to preservation constraints. Examples include shape simplification, sketchbased, and dynamic graph layout. While the orthogonal ordering of vertices is a natural and frequently called for preservation constraint, we show that, unfortunately, it results in severe algorithmic difficulties even for the simplest graphs. More precisely, we show that orthogonalorder preserving rectilinear, octilinear and uniform edge length drawing is N Phard even for paths. Submitted: