This work proposes an eco-driving assistance system (EDAS) based on model predictive control (MPC) with a primary objective to improve the driver’s driving style in an energy-efficient manner. To improve the efficiency of an EDAS, a learning-based approach to model the driver behavior from an urban driving data collected using a dynamic driving simulator is presented. To cluster the driving data of thirty-four participants, unsupervised learning techniques such as principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used. Furthermore, to predict the driver speed error while tracking an advisory speed, both stochastic and determinstic models, namely Stochastic Volatility (SV) and Gated Recurrent Unit (GRU) respectively, are trained. Six new drivers evaluated the proposed concept, whose driving style is classified using a trained temporal convolution network (TCN). Using the predicted driver speed error, the eco-driving advisory speed is compensated and provided as a feedback to the driver via a human-machine interface (HMI). The results reveal that the deterministic model has been able to achieve higher prediction accuracy as compared to the stochastic model. Furthermore, the results also suggest that the drivers using EDAS with driver error compensation have been able to perform better advisory speed tracking and achieve improved energy savings.

One of the main concerns during usage of the current smart mobile devices in public is the vulnerability of password hacking by shoulder-suffering or smudge attack. The traditional user authentication techniques such as PIN code or patterns-based password are easy target of such attacks. In this paper, we propose using simple shapes (e.g., circle, triangle, etc.) to get users' touch behavioral biometrics data. The users are asked to draw over these shapes while the developed system extracts 25 different features (e.g., finger middle stroke and its pressure, velocity, mobile orientation, etc.) for the model training and authentication purpose. The proposed solution is simple for all kinds of users and could solve the problem of password hacking through shoulder-suffering or smudge attacks.

Analysis and understanding of large software systems requires exploring not only the software structure but also associated software metrics over the development releases. Information visualization helps in this regard greatly through interactive visualizations in comparison to exploring these through the source code or traditional software diagrams like UML diagrams. In this paper, we present our developed visualization tool, called HiMVis, that visualizes software hierarchies and metrics through multi-views visualizations on the same screen. HiMVis visualizes packages and class hierarchies through two space-filling interactive layouts. Further, it shows on demand through multiple views more than fifty software metrics information associated to a particular class or interface over all development releases. We provide a number of interaction and filtering options in the tool to make the exploration of the underlying software system more intuitive. We also conducted a brief user study with 10 participants to determine the usability of the developed tool.

We are now living in the era of digital transformation: Innovative and digital business models are transforming the global business world and society. However, the authors of this paper have perceived barriers that prevent requirements engineers from contributing properly to the development of the software systems that underpin the digital transformation. We also realized that breaking down each of these barriers would contribute to requirements engineering (RE) becoming ubiquitous in certain dimensions: RE everywhere, with everyone, for everything, automated, accepting openness, and cross-domain. In this paper, we analyze each dimension of ubiquity in the scope of the interaction between requirements engineers and end users. In particular, we point out the transformation that is required to break down each barrier, present the perspective of the scientific community and our own practical perspective, and discuss our vision on how to achieve this dimension of ubiquity. Our goal is to raise the interest of the research community in providing approaches to address the barriers and move towards ubiquitous RE.

Due to the usage of social media platforms for different purposes in our current digital social life, people are interested to explore and understand their personal networks (called the ego networks) and how their contacts are associated with different social circles on these social media platforms. In this work, we propose an enhanced multi-layered Chord layout to show people' ego networks and the associated social circles in interactive visual forms. This proposed solution enables the users to explore intuitively how their contacts are associated to different social circles through a set of provided interaction and filtering options.

Large displays are one of the core components of visualizing large-scale data sets, allowing users to render a larger amount of information and present it in the corresponding context. However, these displays still have many disadvantages, like the high costs that increase exponentially with display size and the immobility of the display setups. In this paper, we introduce a virtual large screen that is designed as an alternative to physical large displays. It is implemented with the help of the Oculus Rift head mounted display (HMD). Users wearing the virtual glasses are able to see and explore a virtual screen and make use of its size advantages without the cost and location restrictions of the physical counterpart. A preliminary evaluation of our system suggests that the users' perception and cognitive abilities are similar for both working on large physical displays and our large virtual screens.

Providing insight in complex networks or graphs with multivariate data is one of the main challenges for visual analysis today. Much work has been done for visualizing information on nodes, but the space in between has mostly not been used yet. We developed a user study based on two techniques called Partially filled Bars and Bars of Varying Height and asked subjects to perform different tasks. We briefly present both techniques and our design of a large user study. Our goal is to understand the advantages and disadvantages of both approaches compared to each other. After describing our evaluation setup and our initial hypothesis, the results are analyzed, discussed and the most accepted configuration is presented. Finally we briefly discuss the outcome of the user study and our next steps for further investigations.

In this paper, we discuss and evaluate the handling of uncertainty in visual network analysis, i.e. the uncertainty of edge attributes. This can be useful to answer a question like ”How reliable is a flow rate value on a specific edge/pipeline?”. For investigating the most suitable and most intuitive representation of uncertain edge attributes in visual network analysis, we extend the state of the art in uncertain edge visualization. We present and compare four different approaches in a large user study to gain insight into effectiveness, efficiency and user satisfaction. In our user study, we show that dashed lines are the most promising method in general. But, depending on the task, wavy lines as well as blurred lines can be a better choice in terms of efficiency.

In car manufacturing, quality management and control are important parts of the series process. In series production, many parts are controlled in various ways in some or all stages of assembly. While tactile measurements are mostly restricted to the points on an inspection plan, this restriction does not apply to optical measurements. We propose a method based on the theory of Pareto sets (multivariate topological analysis) to cope with the large amount of data produced by optical measurements and to find points of interest on the measured surface in addition to the inspection plan. We describe a method which automatically detects areas of systematic errors on a component and visualizes them on the triangulated surface. The visualization can help experts to decide, whether a detected feature is severe enough to be added to the inspection plan.

In terms of software maintenance and comprehension, the fields of software engineering and software visualization have produced several methods and tools. However, they are typically separate tools in practice. In this paper, we present a novel methodology of combining software analysis and software visualization tools via an interactive visual workflow modeling approach. Standard software analysis tools are also limited in that they support only well-known metrics or are too complicated to use for generating custom software metrics. To address these shortcomings, our approach focuses on visual elements, their configurations, and interconnectivity rather than a data ontology and querying language. In order to test and validate our methodology, we developed a prototype tool called VIMETRIK (Visual Specification of Metrics). Our preliminary evaluation study illustrates the intuitiveness and ease-of-use of our approach with regard to understanding software measurement and analysis data.

The current mobile paradigm is in many ways fundamentally different from the conventional desktop paradigm due to many factors such as multi-touch gesture interaction, usage of sensors, single-task focused model, etc. These factors mean several new challenges for the interaction designers with regard to communicating their ideas and thoughts during early design activities, which they might be unable to tackle properly using traditional prototyping techniques. Therefore, we envision that research must address the need for a change in existing prototyping techniques as well as focus on novel prototyping approaches and frameworks that would support not only the interaction design process but also the whole development process of mobile app development. In the footsteps of the first workshop, PID-MAD 2014 provides a platform to the interested communities for discussing issues and will bring together researchers and practitioners for sharing their knowledge and experience in order to tackle the upcoming challenges.

Collaboration between users of a system is often a crucial factor for reaching given goals in an effective and efficient way. However, in many application domains, the current systems do not sufficiently support collaborative work (sometimes they even don't support it at all). One good example is geographical information systems (GIS), that usually only follow an one user at one time approach. In this paper, we present the development of a scalable Multi-user Geographical Information System (MuGIS). With MuGIS it is now possible to integrate large display environments with mobile smart devices for remote control. The system is deployed as a client-server architecture. It uses the NASA World Wind Java framework and SOAP web services for communication. On the client side, all common mobile smart devices are supported. The underlying concept provides different user roles and multi-user identification.

In this work, we present a new technique, called ExpanD, for expanding compound nodes in stereoscopic platforms. In this technique, stereoscopic depth is used to encode the structural relationships in compound graphs using the containment representation, while explicit edges are used to represent the adjacency relations between the graph nodes. Further, stereoscopic depth is used to show the parent-child relations in such a manner that the children level is rendered in a plane closer to the viewer than the parent node. The technique provides a novel interactive operation for expanding or contracting nodes in order to align graph nodes in the 3D space with minimum occlusion. Different visual cues are used together to encode other data aspects, e.g., color to encode node status, shape to encode node type, and stereoscopic depth to encode hierarchical relations between nodes.

One of the main challenges in the maintenance of large-scale software systems is to ascertain the underlying software structure and to analyze its evolution. In this paper we present a tool to assist software architects and developers in not only understanding the software structure of their system but more importantly to track the insertion, removal, or modification of components over time. The tool is based on the idea that the above-mentioned stakeholders should have an intuitive, efficient, and effective means to detect when, where, and what structural changes took place. The main components include an interactive visualization that provides an overview of these changes. The usefulness of this approach is highlighted through a summary of a user study we conducted.

Recent changes in the mobile environment; such as the addition of multi-touch gestures, usage of sensors, or single-focused mobile apps; brought several challenges for interaction designers in communicating their ideas and thoughts enduring early design activities. Traditional prototyping techniques may not provide sufficient support due to the lack of current mobile interaction paradigms in them. Therefore, a shift is required in prototyping techniques and approaches in order to support properly the interaction design process of mobile application development for the current mobile environment.

Providing interactive mockups of mobile applications in designing phases introduces new challenges for interaction designers compared to the traditional way of static mockups. In particular, the complexity of this process increases when it comes to enabling the user to actually explore the intended user experience of the mobile environment by enhancing traditional handmade sketches or tool-generated wireframes with concrete mobile interaction elements. We introduce a framework, called i2ME (interactive Mockup-Building for Mobile Environment), for building interactive mockups with concrete mobile interaction elements. The framework enhances the static mockups (handmade or tool-generated) with screen transitions and multi-touch gestures, and enables the deployment of the resulting HTML5+JavaScript based interactive mockups to multiple platforms and device classes.

In recent years, high-resolution displays have become increasingly important to decision makers and scientists because large screens combined with a high pixel count facilitate content rich, simultaneous display of computer-generated imagery and high-definition video data from multiple sources. Tiled displays are attractive due to their extended screen real estate, scalability, and low cost. LCD panels are usually preferred over projectors because of their superior resolution. One of the drawbacks of LCD-based tiled displays is the fact that users sometimes get distracted by the screens' bezels, which cause discontinuities in rendered images, animations, or videos. Most conventional solutions either ignore the bezels and display all pixels, causing objects to become distorted, or eliminate the pixels that would normally fall under the bezels, causing pixels to be missing in the display of static images. In animations, the missing pixels will eventually reappear when the object moves, providing an experience that is similar to looking through a French window. In this paper, we present a new scalable approach that leads neither to discontinuities nor to significant loss of information. By projecting onto the bezels, we demonstrate that a combination of LCD-based tiled displays and projection significantly reduces the bezel problem. Our technique eliminates ambiguities that commonly occur on tiled displays in the fields of information visualization, visual data analysis, human-computer interaction, and scientific data display. It improves the usability of multimonitor systems by virtually eliminating the bezels. We describe a setup and provide results from an evaluation experiment conducted on a 3 x 3 and on a 10 x 5 tiled display wall.

We present a novel user interface in the form of a complementary virtual environment for managing personal document archives, i.e., for document filing and retrieval. Our implementation of a spatial medium for document interaction, exploratory search and active navigation plays to the strengths of human visual information processing and further stimulates it.

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.

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.

With powerful graphics hardware becoming affordable for everyone, there is an increasing tendency towards a new generation of user interfaces, with the focus shifting from traditional two-dimensional desktops to three-dimensional virtual environments. Therefore, there is a growing need for applicable immersive interaction metaphors to manipulate these environments. In our paper we propose a gesture recognition engine using an inexpensive data glove with integrated 6 DOF tracking. Despite of noisy input data from the glove, we are able to achieve reliable and flexible gesture recognition. New gestures can be trained easily and existing gestures can be individually adapted for different users

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

This poster abstract presents a scalable information visualization system for mobile devices and desktop systems. It is designed to support the operation and the workflow of wastewater systems. The regarded information data includes general information about buildings and units, process data, occupational safety regulations, work directions and first aid instructions in case of an accident. Technically, the presented framework combines visualization with agent technology in order to automatically scale various visualization types to fit on different platforms like PDAs (Personal Digital Assistants) or Tablet PCs. The implementation is based on but not limited to SQL, JSP, HTML and VRML.

The accelerating evolution of information visualization research in the last few years has led to several specific system implementations. The obvious drawbacks of this development are highly dependent software systems, which are only available for a restricted number of users. Today, due to the remarkable advances in hardware and software technologies, not only very expensive graphics workstations, but also low-cost PCs are capable of running computational demanding visualization systems. Furthermore, the rapid development of the medium World Wide Web along with state-of-the-art Internet programming techniques has led to a trend toward more generally usable visualization systems. In this paper, we propose a functional developer's framework for general Web-based visualization systems which makes intelligent use of application specific software and hardware components on the server side, as well as Java's benefits on the client side. To demonstrate the framework's abilities, we have applied it to two practical visualization tasks and report on our experience concerning practicability and pitfalls.