Semantic multimedia remote display for mobile thin clients

Current remote display technologies for mobile thin clients convert practically all types of graphical content into sequences of images rendered by the client. Consequently, important information concerning the content semantics is lost. The present paper goes beyond this bottleneck by developing a semantic multimedia remote display. The principle consists of representing the graphical content as a real-time interactive multimedia scene graph. The underlying architecture features novel components for scene-graph creation and management, as well as for user interactivity handling. The experimental setup considers the Linux X windows system and BiFS/LASeR multimedia scene technologies on the server and client sides, respectively. The implemented solution was benchmarked against currently deployed solutions (VNC and Microsoft-RDP), by considering text editing and WWW browsing applications. The quantitative assessments demonstrate: (1) visual quality expressed by seven objective metrics, e.g., PSNR values between 30 and 42 dB or SSIM values larger than 0.9999; (2) downlink bandwidth gain factors ranging from 2 to 60; (3) real-time user event management expressed by network round-trip time reduction by factors of 4-6 and by uplink bandwidth gain factors from 3 to 10; (4) feasible CPU activity, larger than in the RDP case but reduced by a factor of 1.5 with respect to the VNC-HEXTILE

Dash Sylvereye:A Python Library for Dashboard-Driven Visualization of Large Street Networks

State-of-the-art open graph visualization tools like Gephi, KeyLines, and Cytoscape are not suitable for studying street networks with thousands of roads since they do not support simultaneously polylines for edges, navigable maps, GPU-accelerated rendering, interactivity, and the means for visualizing multivariate data. To fill this gap, we present Dash Sylvereye: a new Python library to produce interactive visualizations of primal street networks on top of tiled web maps. Thanks to its integration with the Dash framework, Dash Sylvereye can be used to develop web dashboards around temporal and multivariate street data. This is achieved by coordinating the various elements of a Dash Sylvereye visualization with other plotting and UI components provided by Dash. Additionally, Dash Sylvereye provides convenient functions to easily import OpenStreetMap street topologies obtained with the OSMnx library. Moreover, Dash Sylvereye uses WebGL for GPU-accelerated rendering when redrawing the road network. We conduct experiments to assess the performance of Dash Sylvereye on a commodity computer when exploiting software acceleration in terms of frames per second, CPU time, and frame duration. We show that Dash Sylvereye can offer fast panning speeds, close to 60 FPS, and CPU times below 20 ms, for street networks with thousands of edges, and above 24 FPS, and CPU times below 40 ms, for networks with dozens of thousands of edges. Additionally, we conduct a performance comparison against two state-of-the-art street visualization tools. We found Dash Sylvereye to be competitive when compared to the state-of-the-art visualization libraries Kepler.gl and city-roads. Finally, we describe a web dashboard application that exploits Dash Sylvereye for the analysis of a SUMO vehicle traffic simulation

Dash Sylvereye:A WebGL-powered Library for Dashboard-driven Visualization of Large Street Networks

State-of-the-art open network visualization tools like Gephi, KeyLines, and Cytoscape are not suitable for studying street networks with thousands of roads since they do not support simultaneously polylines for edges, navigable maps, GPU-accelerated rendering, interactivity, and the means for visualizing multivariate data. To fill this gap, the present paper presents Dash Sylvereye: a new Python library to produce interactive visualizations of primal street networks on top of tiled web maps. Thanks to its integration with the Dash framework, Dash Sylvereye can be used to develop web dashboards around temporal and multivariate street data by coordinating the various elements of a Dash Sylvereye visualization with other plotting and UI components provided by the Dash framework. Additionally, Dash Sylvereye provides convenient functions to easily import OpenStreetMap street topologies obtained with the OSMnx library. Moreover, Dash Sylvereye uses WebGL for GPU-accelerated rendering when redrawing the road network. We conduct experiments to assess the performance of Dash Sylvereye on a commodity computer when exploiting software acceleration in terms of frames per second, CPU time, and frame duration. We show that Dash Sylvereye can offer fast panning speeds, close to 60 FPS, and CPU times below 20 ms, for street networks with thousands of edges, and above 24 FPS, and CPU times below 40 ms, for networks with dozens of thousands of edges. Additionally, we conduct a performance comparison against two state-of-the-art street visualization tools. We found Dash Sylvereye to be competitive when compared to the state-of-the-art visualization libraries Kepler.gl and city-roads. Finally, we describe a web dashboard application that exploits Dash Sylvereye for the analysis of a SUMO vehicle traffic simulation

Personalisation and recommender systems in digital libraries

Widespread use of the Internet has resulted in digital libraries that are increasingly used by diverse communities of users for diverse purposes and in which sharing and collaboration have become important social elements. As such libraries become commonplace, as their contents and services become more varied, and as their patrons become more experienced with computer technology, users will expect more sophisticated services from these libraries. A simple search function, normally an integral part of any digital library, increasingly leads to user frustration as user needs become more complex and as the volume of managed information increases. Proactive digital libraries, where the library evolves from being passive and untailored, are seen as offering great potential for addressing and overcoming these issues and include techniques such as personalisation and recommender systems. In this paper, following on from the DELOS/NSF Working Group on Personalisation and Recommender Systems for Digital Libraries, which met and reported during 2003, we present some background material on the scope of personalisation and recommender systems in digital libraries. We then outline the working group’s vision for the evolution of digital libraries and the role that personalisation and recommender systems will play, and we present a series of research challenges and specific recommendations and research priorities for the field

Interaktion mit Medienfassaden : Design und Implementierung interaktiver Systeme für große urbane Displays

Media facades are a prominent example of the digital augmentation of urban spaces. They denote the concept of turning the surface of a building into a large-scale urban screen. Due to their enormous size, they require interaction at a distance and they have a high level of visibility. Additionally, they are situated in a highly dynamic urban environment with rapidly changing conditions, which results in settings that are neither comparable, nor reproducible. Altogether, this makes the development of interactive media facade installations a challenging task. This thesis investigates the design of interactive installations for media facades holistically. A theoretical analysis of the design space for interactive installations for media facades is conducted to derive taxonomies to put media facade installations into context. Along with this, a set of observations and guidelines is provided to derive properties of the interaction from the technical characteristics of an interactive media facade installation. This thesis further provides three novel interaction techniques addressing the form factor and resolution of the facade, without the need for additionally instrumenting the space around the facades. The thesis contributes to the design of interactive media facade installations by providing a generalized media facade toolkit for rapid prototyping and simulating interactive media facade installations, independent of the media facade’s size, form factor, technology and underlying hardware.Die wachsende Zahl an Medienfassenden ist ein eindrucksvolles Beispiel für die digitale Erweiterung des öffentlichen Raums. Medienfassaden beschreiben die Möglichkeit, die Oberfläche eines Gebäudes in ein digitales Display zu wandeln. Ihre Größe erfordert Interaktion aus einer gewissen Distanz und führt zu einer großen Sichtbarkeit der dargestellten Inhalte. Medienfassaden-Installationen sind bedingt durch ihre dynamische Umgebung nur schwerlich vergleich- und reproduzierbar. All dies macht die Entwicklung von Installationen für Medienfassaden zu einer großen Herausforderung. Diese Arbeit beschäftigt sich mit der Entwicklung interaktiver Installationen für Medienfassaden. Es wird eine theoretische Analyse des Design-Spaces interaktiver Medienfassaden-Installationen durchgeführt und es werden Taxonomien entwickelt, die Medienfassaden-Installationen in Bezug zueinander setzen. In diesem Zusammenhang werden ausgehend von den technischen Charakteristika Eigenschaften der Interaktion erarbeitet. Zur Interaktion mit Medienfassaden werden drei neue Interaktionstechniken vorgestellt, die Form und Auflösung der Fassade berücksichtigen, ohne notwendigerweise die Umgebung der Fassade zu instrumentieren. Die Ergebnisse dieser Arbeit verbessern darüber hinaus die Entwicklung von Installationen für Medienfassaden, indem ein einheitliches Medienfassaden-Toolkit zum Rapid-Prototyping und zur Simulation interaktiver Installationen vorgestellt wird, das unabhängig von Größe und Form der Medienfassade sowie unabhängig von der verwendeten Technologie und der zugrunde liegenden Hardware ist