Katja Einsfeld’s research while affiliated with Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau and other places

The design and the operation of urban drainage systems and wastewater treatment plants (WWTP) have become increasingly complex. This complexity is due to increased requirements concerning process technology, technical, environmental, economical, and occupational safety aspects. The plant operator has access not only to some timeworn filers and measured parameters but also to numerous on-line and off-line parameters that characterize the current state of the plant in detail. Moreover, expert databases and specific support pages of plant manufactures are accessible through the World Wide Web. Thus, the operator is overwhelmed with predominantly unstructured data. The first part of our contribution describes the project SIMLAR, which covered information visualization approaches for various tasks and devices. Visualizations for mobile devices are especially useful in the case of large, distributed wastewater systems. Especially in the case of an alarm, mobile process information can help to determine if it is necessary to visit the plant. The second part details the project KOMPLETT, which researches intuitive visualization systems for complex plants. Considering the fact that the plant is unmanned and thus even non-experts have to cope with the system, it has to meet diverse requirements: it has to visually and intuitively indicate trends and irregular behavior of quantitative data.

One important intention of human-centered information visualization is to represent huge amounts of abstract data in a visual representation that allows even users from foreign application domains to interact with the visualization, to understand the underlying data, and finally, to gain new, application-related knowledge. The visualization will help experts as well as non-experts to link previously or isolated knowledge-items in their mental map with new insights. Our approach explicitly supports the process of linking knowledge-items with three concepts. At first, the representation of data items in an ontology categorizes and relates them. Secondly, the use of various visualization techniques visually correlates isolated items by graph-structures, layout, attachment, integration, or hyperlink techniques. Thirdly, the intensive use of visual metaphors relates a known source domain to a less known target domain. In order to realize a scenario of these concepts, we developed a visual interface for non-experts to maintain complex wastewater treatment plants. This domain-specific application is used to give our concepts a meaningful background.

Within the research project KOMPLETT an advanced sanitation scheme for separated grey-and blackwater is developed in order to close domestic water and material cycle.In the second project phase two pilot plants were operated treating separated grey-and blackwater flow in order to achieve optimum water qualities for reuse.Both plants discharge effluent of very high quality, meeting different urban reuse quality standards.In particular for greywater the effluent quality reached highest requirements for utilization, e.g.drinking water standards.Simultaneously new sanitary products and an intelligent diagnosis system were developed and tested.In 2008 the final pilot phase has been started.For this the KOMPLETT-treatment plant has been integrated in an office building for about 150-200 employees as a demonstration plant.There the systems of sanitary equipment, treatment and visualization are coupled and water cycles are closed for the first time.This paper describes the results of the second pro ject phase.

In order to make use of domain knowledge and thus to create less abstract visualizations of the available information, we propose to integrate information visualization techniques in 3D visualizations of the application subject. We describe a framework that is build on an ontology, an hierarchical visualization toolkit, and a modular concept of modeling 3D layouts. This allows us to integrate semantically related information directly in the scene. We achieve this integration by modifying the real world geometry in several ways. Our concept helps non-expert users to intuitively interact with the system and to understand what is going on.

Today, there are many systems with large amounts of com-plex data sets. Visualizing these systems in a way that en-lightens the user and provides a profound understanding of the respective information space is one of the big information visualization research challenges. Keim [10] states that it is no longer possible to display an overview of these systems as proposed in Shneiderman's information seeking mantra [18]. To overcome this incapacity and to provide a solution to the dilemma of time multiplexing-vs. space multiplexing techniques, we propose the context-sensitive use of a collec-tion of animated 3D metaphors. These metaphors are inte-grated in a flexible framework called HANNAH. This pro-vides the possibility to interconnect media of various types in order to bridge the semantic gab as required for human-centered applications according to Elgammal [6].

In this paper we describe an adaptable multi-purpose 3D user interface for complex heterogeneous information. The framework allows to create visualization instruments by hierarchically combining small visualization widgets. We integrate well known 3D visualization tools in our system and also present new metaphors like the RotaryDiagram. Due to the modular architecture and the underlying ontology we are able to build intuitive visualizations that allow direct manipulation, that directly and vividly respond to user actions and adopt to changing needs. The visualizations provide the user with multiple perspectives on the data and semantic relations between items of various perspectives. The effectiveness of our proposed concepts for 3D information visualization systems is being proven by applying them to an user interface for monitoring, controlling, and optimization of a complex wastewater treatment plant.

Current sanitation concepts of decentralised wastewater treatment and reuse raise the issue of monitoring and maintenance of such systems. To guarantee high quality of the recycled water, systems with high requirements concerning process technology are essential. With increasing numbers of decentralised treatment systems spread over far distances it will become more and more impossible and uneconomic to have expert personnel on site. Therefore, new visualisation and intelligent information systems are necessary. The paper describes the structure and 3D-demonstrations as a base for information visualisation. Up-to-date visualisation techniques, facilitating the cognition of context-adapted information, make it possible to maximise the amount of information presented to the user without overwhelming her or him. Concerning diagnosis and decision support systems in the domain of wastewater treatment, several interesting approaches are presented, estimating their applicability for decentralised wastewater treatment systems. The intelligent decision support system presented here consists of a combined ontology- and case-based reasoning system in addition to a process monitoring system. It is responsible for plausibility checks, error diagnosis, solution proposals, and optimisation suggestions.

Although information visualization claims to provide the means to induce mental models of any kind of data, the visualization of semantic information is still an open field of research. Existing approaches either concentrate on the visualization of documents without additional metadata or produce unintuitive expert graphics. This paper seeks to fill this gap by presenting a semantic information visualization system with a dynamic 3D interface and intuitive metaphors. The application called DocuWorld visualizes documents, document meta-data, and semantic relations between documents. The general visualization and navigation metaphor called Thought Wizard Metaphor allows user- and context-sensitive adaption of visualization modes and visualization environments

The efficient operation of complex industrial processes requires the organization of large amounts of heterogeneous data. We explain that both, these data characteristics as well as the need for context sensitive information interfaces, require the design of visualizations with multiple dynamic perspectives on the data. The benefits of animated 3D information visualization are stated and an efficient motion parallax technique is proposed. Additionally, a navigation concept for information rich semantic 3D environments that frees the user from part of the mental load is described. We present new metaphors for visualizing the data in those perspectives like Cone-View, animated 3D Explosion View, and Rotary Diagram. Moreover, a labeling technique for dynamic 3D environments is explained. Although still at an early state of development, our implementation of this toolbox of concepts, metaphors, and techniques promises to indicate an new generation of industrial process visualization systems.