Visualisation of ATM network connectivity and topology

Bibliography: leaves 110-113.ATM and dynamic reconfiguration allow for rapid changes in a virtual path network depending on traffic load and future demands. This technology improves the utilisation, lowers the call blocking probability and increases the overall performance of a network. However, it poses several management difficulties when user intervention is required to resolve complex routing problems. In this dissertation, we describe a visualisation approach which uses a network metaphor to aid administrators in managing dynamic ATM networks. Our metaphor scales well for networks of varying size, addresses the cluttering problem experienced by past metaphors and maintains the overall network context while providing additional support for navigation and interaction

From insights to innovations : data mining, visualization, and user interfaces

This thesis is about data mining (DM) and visualization methods for gaining insight into multidimensional data. Novel, exploratory data analysis tools and adaptive user interfaces are developed by tailoring and combining existing DM and visualization methods in order to advance in different applications. The thesis presents new visual data mining (VDM) methods that are also implemented in software toolboxes and applied to industrial and biomedical signals: First, we propose a method that has been applied to investigating industrial process data. The self-organizing map (SOM) is combined with scatterplots using the traditional color linking or interactive brushing. The original contribution is to apply color linked or brushed scatterplots and the SOM to visually survey local dependencies between a pair of attributes in different parts of the SOM. Clusters can be visualized on a SOM with different colors, and we also present how a color coding can be automatically obtained by using a proximity preserving projection of the SOM model vectors. Second, we present a new method for an (interactive) visualization of cluster structures in a SOM. By using a contraction model, the regular grid of a SOM visualization is smoothly changed toward a presentation that shows better the proximities in the data space. Third, we propose a novel VDM method for investigating the reliability of estimates resulting from a stochastic independent component analysis (ICA) algorithm. The method can be extended also to other problems of similar kind. As a benchmarking task, we rank independent components estimated on a biomedical data set recorded from the brain and gain a reasonable result. We also utilize DM and visualization for mobile-awareness and personalization. We explore how to infer information about the usage context from features that are derived from sensory signals. The signals originate from a mobile phone with on-board sensors for ambient physical conditions. In previous studies, the signals are transformed into descriptive (fuzzy or binary) context features. In this thesis, we present how the features can be transformed into higher-level patterns, contexts, by rather simple statistical methods: we propose and test using minimum-variance cost time series segmentation, ICA, and principal component analysis (PCA) for this purpose. Both time-series segmentation and PCA revealed meaningful contexts from the features in a visual data exploration. We also present a novel type of adaptive soft keyboard where the aim is to obtain an ergonomically better, more comfortable keyboard. The method starts from some conventional keypad layout, but it gradually shifts the keys into new positions according to the user's grasp and typing pattern. Related to the applications, we present two algorithms that can be used in a general context: First, we describe a binary mixing model for independent binary sources. The model resembles the ordinary ICA model, but the summation is replaced by the Boolean operator OR and the multiplication by AND. We propose a new, heuristic method for estimating the binary mixing matrix and analyze its performance experimentally. The method works for signals that are sparse enough. We also discuss differences on the results when using different objective functions in the FastICA estimation algorithm. Second, we propose "global iterative replacement" (GIR), a novel, greedy variant of a merge-split segmentation method. Its performance compares favorably to that of the traditional top-down binary split segmentation algorithm.reviewe

Virtual software in reality

Software visualisation is an important weapon in the program comprehension armoury. It is a technique that can, when designed and used effectively, aid in understanding existing program code. It can achieve this by displaying information in new and different forms, which may make obvious something missed in reading the code. It can also be used to present many aspects of the data at once. Software, despite many software engineering advances in requirements, design and implementation techniques, continues to be complex and large and if anything seems to be growing in these respects. This means that techniques that failed to aid comprehension and maintenance are certainly not going to be able to deal with the current software. Therefore this area requires research to be able to suggest solutions to deal with the information overload that is sure to occur. There are several issues that this thesis addresses; all of them related to the creation of software visualisation systems that are capable of being used and useful well into the next generation of software systems. The scale and complexity of software are pressing issues, as is the associated information overload problem that this brings. In an attempt to address this problem the following are considered to be important: abstractions, representations, mappings, metaphors, and visualisations. These areas are interrelated and the first four enable the final one, visualisations. These problems are not the only ones that face software visualisation systems. There are many that are based on the general theory of the applicability of the technique to such tasks as program comprehension, rather than the detail of how a particular code fragment is shown. These problems are also related to the enabling technology of three- dimensional visualisations; virtual reality. In summary the areas of interest are: automation, evolution, scalability, navigation and interaction, correlation, and visual complexity. This thesis provides an exploration of these identified areas in the context of software visualisation. Relationships that describe, and distinguish between, existing and future software visualisations are presented, with examples based on recent software visualisation research. Two real world metaphors (and their associated mappings and representations) are defined for the purpose of visualising software as an aid to program comprehension. These metaphors also provide a vehicle for the exploration of the areas identified above. Finally, an evaluation of the visualisations is presented using a framework developed for the comparative evaluation of three-dimensional, comprehension oriented, software visualisations. This thesis has shown the viability of using three-dimensional software visualisations. The important issues of automation, evolution, scalability, and navigation have been presented and discussed, and their relationship to real world metaphors examined. This has been done in conjunction with an investigation into the use of such real world metaphors for software visualisation. The thesis as a whole has provided an important examination of many of the issues related to these types of visualisation in the context of software and is therefore a valuable basis for future work in this area

A sketching-oriented design method for information visualization software.

The aim of this research is to describe a useful approach for supporting creativity and problem-solving in the design of Information Visualization software. This type of software is useful for helping people to understand large or complex collections of data by making the data easier to see and use. Because it can be so helpful, many people are motivated to create visualization software to address their own unique problems of understanding data. However, the techniques which visualizations use to enhance cognition of data are not widely known. Also, there are currently few resources which comprehensively describe a method for designing novel visualizations. Consequently, people who seek to build new Information Visualization tools are left to consult design examples, guidelines, and reference models, which do not adequately describe the visualization design process. The key question of the research concerns how Information Visualization methodologies should account for representation of the user, existing visualization design knowledge, and sketching. Given that the current methods of Information Visualization design are incomplete and show evidence of significant shortcomings, how can novice visualization design teams bridge these gaps by using methods from other design disciplines to successfully create effective visualizations To investigate this question, several studies were conducted. Also, a design methodology called So Viz was developed. It incorporates a participatory design approach, using sketching and visualization design patterns to support creativity and problem-solving. A prototype was designed using the SoViz approach. The key contributions of this thesis are results which show that Information Visualization designers can benefit from using this method. The thesis presents the results of using SoViz to create an Information Visualization prototype and describes the theoretical consequences for Information Visualization methodology

Engineering Perceptually Effective Visualizations for Abstract Data

Data Stephen G. Eick * AT&T Bell Laboratories 21 March 1995 Abstract Visualization is an emerging discipline practiced by skilled artisans who are hand-crafting the current systems. In the process of constructing many displays of abstract corporate data, we have distilled some aspects of the successful displays into a set of guidelines for creating perceptually effective visualizations. By describing our guidelines, illustrating their usage with several novel examples, and discussing our software infrastructure, we hope to further the progress of visualization from a craft into a production technology. 1 Introduction Visualization is a powerful link between the two most powerful information processing systems--the human mind and the modern computer. It is a key technology for extracting information, and therefore it is becoming more and more necessary in our increasingly information-rich society. Visualization techniques can enable us to navigate and explore the fast growing numbe..