Tree layouts are among the key approaches for network visualization, and are of particular importance for exploring the hierarchical structure of networks. However, visualizations of the overall ...network structure and its hierarchical relationships can rarely be optimized simultaneously. This paper presents a radial layout algorithm called PLANET that enables users to explore the network structure from a root node, while maintaining readability. In order to distribute the nodes evenly and minimize edge crossings, we define a list of angle assignment rules for displaying child nodes which can automatically maximize the tunable angles between parent and child nodes, and to uniformly divide the angles of child nodes. Using these rules, the structural properties of the network such as hubs can be properly conveyed, and the readability of nodes that are far from the root can be guaranteed. Our experimental results show that PLANET is comparable to similar algorithms in terms of execution time, and gives better performance in terms of node distribution, variance of edge length and number of edge crossing; these advantages become greater for networks with large diameters.
•A parent-centric layout algorithm for networks (PLANET) is proposed.•PLANET show clear hierarchical relationship without compromising the clarity of the overall network structure.•PLANET produces drawings of spanning trees with uniform node distribution and minimum number of edge crossing.•The time complexity of PLANET is O(N), which is relatively low.•Users can adjust the node size and edge length of each layer as needed with PLANET.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A composite indicator (CI) is a measuring and benchmark tool used to capture multi-dimensional concepts, such as Information and Communication Technology (ICT) usage. Individual indicators are ...selected and combined to reflect a phenomena being measured. Visualization of a composite indicator is recommended as a tool to enable interested stakeholders, as well as the public audience, to better understand the indicator components and evolution overtime. However, existing CI visualizations introduce a variety of solutions and there is a lack in CI's visualization guidelines. Radial visualizations are popular among these solutions because of CI's inherent multi-dimensionality. Although in dispute, Radar-charts are often used for CI presentation. However, no empirical evidence on Radar's effectiveness and efficiency for common CI tasks is available. In this paper, we aim to fill this gap by reporting on a controlled experiment that compares the Radar chart technique with two other radial visualization methods: Flowercharts as used in the well-known OECD Betterlife index, and Circle-charts which could be adopted for this purpose. Examples of these charts in the current context are shown in Figure 1. We evaluated these charts, showing the same data with each of the mentioned techniques applying small multiple views for different dimensions of the data. We compared users' performance and preference empirically under a formal task-taxonomy. Results indicate that the Radar chart was the least effective and least liked, while performance of the two other options were mixed and dependent on the task. Results also showed strong preference of participants toward the Flower chart. Summarizing our results, we provide specific design guidelines for composite indicator visualization.
An optimization framework for global optimization of the cable layout topology for offshore wind farm (OWF) is presented. The framework designs and compares closed‐loop and radial layouts for the ...collection system of OWFs. For the former, a two‐stage stochastic optimization program based on a mixed integer linear programming (MILP) model is developed, while for the latter, a hop‐indexed full binary model is used. The purpose of the framework is to provide a common base for assessing both designs economically, using the same underlying contingency treatment. A discrete Markov model is implemented for calculating the cable failure probability, useful for estimating the time under contingency for multiple power generation scenarios. The objective function supports simultaneous optimization of (i) initial investment (network topology and cable sizing), (ii) total electrical power loss costs and (iii) operation costs due to energy curtailment from cable failures. Constraints are added accounting for common engineering aspects. The applicability of the full method is demonstrated by tackling three differently sized real‐world OWFs. Results show that (i) the profitability of either topology type depends strongly on the project size and wind turbine rating. Closed loop may be a competitive solution for large‐scale projects where large amounts of energy are potentially curtailed. (ii) The stochastic model presents low tractability to tackle large‐scale instances, increasing the required computing time and memory resources. (iii) Strategies must be adopted in order to apply stochastic optimization for modern OWFs, intending analytically or numerically simplification of mathematical models.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Geoscience observation data refer to the datasets consisting of time series of multiple parameters generated from the sensors at fixed locations. Although a few works have attempted to visualize such ...data, none of them views these data as a specific type and attempts to show the overview in all the space, time and attribute aspects. It is important for domain experts to select the subsets of interest from huge amounts of observation data according to the high level patterns shown in the overview. We present a novel approach to visualize geoscience observation data in a compact radial view. Our solution consists of three visual elements. A map showing the spatial aspect is in the center of the visualization, while temporal and attribute aspects are seamlessly combined with the spatial information. Our approach is equipped with interactive mechanisms for highlighting the selected features, adjusting the display range, as well as interactively generating a fisheye view. We demonstrate the usability of our approach with three case studies of different domains. Eye tracking records and user feedbacks obtained in a small experiment also prove the effectiveness of our approach.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We present a new approach to visualizing the climate data of multi-dimensional, time-series, and geo-related characteristics. Our approach integrates three new highly interrelated visualization ...techniques, and uses the same input data types as in the traditional model-based analysis methods. As the main visualization view, Global Radial Map is used to identify the overall state of climate changes and provide users with a compact and intuitive view for analyzing spatial and temporal patterns at the same time. Other two visualization techniques, providing complementary views, are specialized in analysing time trend and detecting abnormal cases, which are two important analysis tasks in any climate change study. Case studies and expert reviews have been conducted, through which the effectiveness and scalability of the proposed approach has been confirmed.
Polar coordinates have been widely used in various techniques of interactive data visualization. The spatial organization through circular and radial layouts is implemented in a wide range of ...statistical charts and plots and is applicable for space-filling techniques and for node-link-group diagrams. Different arrangements of dots, lines and areas in polar coordinates create grids for data distribution, aggregation and linking.
This work is devoted to the study of visual notations of data and their relationships and proposes an outline of their application in designing node-link-group diagrams, in order to arrange the geometric solutions at functional and logical levels of the visual representation.
In this paper, we present the design, implementation and an evaluation of the "Foresighted Heat Ring", a technique for visualizing the productivity and collaborative ness of researchers in dynamic ...networks. Our approach combines a heat map and a foresighted radial layout with physiological theories of visual perception to achieve visual stability on the drawing. The technique has been embedded into a network analysis workbench and applied to a time-sliced nanotechnology publication network from Web of Science. Based on this scenario, an evaluation with twenty participants was conducted. The results suggest that there are three factors that allow a visualization technique to be perceived as stable.
Supporting menu design with radial layouts Samp, Krystian; Decker, Stefan
Proceedings of the International Conference on Advanced Visual Interfaces,
05/2010
Conference Proceeding
One of the ways of decreasing selection times in displayed menus is through the use of radial layouts which shorten distances to the items and increase the item sizes. Previous work on radial menus ...does not demonstrate that radial layouts are beneficial for menu hierarchies. The paper focuses on this topic.
We compare two main characteristics of radial and linear layouts: a) the time it takes to find an item (i.e. visual search time), b) the time it takes to navigate to an item (i.e. pointing time). We use objective and subjective measures, two menu sizes, three menu levels, one linear and three radial layout variations.
We also present requirements and the Compact Radial Layout (CRL) design which supports menu hierarchies. We assess its performance for novice and expert users.
Wikipedia is a large and popular daily information source for millions of people. How are articles distributed by topic area, and what is the semantic coverage of Wikipedia? Using manual methods it ...is impractical to determine this. We present the design of an information visualization tool that produces overview diagrams of Wikipedia's articles distributed according to category relationships, and show examples of visualizing English Wikipedia.
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