Transferable atomic multipole machine learning models for small organic molecules

Accurate representation of the molecular electrostatic potential, which is often expanded in distributed multipole moments, is crucial for an efficient evaluation of intermolecular interactions. Here we introduce a machine learning model for multipole coefficients of atom types H, C, O, N, S, F, and Cl in any molecular conformation. The model is trained on quantum chemical results for atoms in varying chemical environments drawn from thousands of organic molecules. Multipoles in systems with neutral, cationic, and anionic molecular charge states are treated with individual models. The models' predictive accuracy and applicability are illustrated by evaluating intermolecular interaction energies of nearly 1,000 dimers and the cohesive energy of the benzene crystal.Comment: 11 pages, 6 figure

Appearance-based localization for mobile robots using digital zoom and visual compass

This paper describes a localization system for mobile robots moving in dynamic indoor environments, which uses probabilistic integration of visual appearance and odometry information. The approach is based on a novel image matching algorithm for appearance-based place recognition that integrates digital zooming, to extend the area of application, and a visual compass. Ambiguous information used for recognizing places is resolved with multiple hypothesis tracking and a selection procedure inspired by Markov localization. This enables the system to deal with perceptual aliasing or absence of reliable sensor data. It has been implemented on a robot operating in an office scenario and the robustness of the approach demonstrated experimentally

Effect of screen presentation on text reading and revising. International Journal of Human-Computer Studies

Two studies using the methods of experimental psychology assessed the effects of two types of text presentation (page-by-page vs. scrolling) on participants' performance while reading and revising texts. Greater facilitative effects of the page-by-page presentation were observed in both tasks. The participants' reading task performance indicated that they built a better mental representation of the text as a whole and were better at locating relevant information and remembering the main ideas. Their revising task performance indicated a larger number of global corrections (which are the most difficult to make)

Interacting "Through the Display"

The increasing availability of displays at lower costs has led to a proliferation of such in our everyday lives. Additionally, mobile devices are ready to hand and have been proposed as interaction devices for external screens. However, only their input mechanism was taken into account without considering three additional factors in environments hosting several displays: first, a connection needs to be established to the desired target display (modality). Second, screens in the environment may be re-arranged (flexibility). And third, displays may be out of the user’s reach (distance). In our research we aim to overcome the problems resulting from these characteristics. The overall goal is a new interaction model that allows for (1) a non-modal connection mechanism for impromptu use on various displays in the environment, (2) interaction on and across displays in highly flexible environments, and (3) interacting at variable distances. In this work we propose a new interaction model called through the display interaction which enables users to interact with remote content on their personal device in an absolute and direct fashion. To gain a better understanding of the effects of the additional characteristics, we implemented two prototypes each of which investigates a different distance to the target display: LucidDisplay allows users to place their mobile device directly on top of a larger external screen. MobileVue on the other hand enables users to interact with an external screen at a distance. In each of these prototypes we analyzed their effects on the remaining two criteria – namely the modality of the connection mechanism as well as the flexibility of the environment. With the findings gained in this initial phase we designed Shoot & Copy, a system that allows the detection of screens purely based on their visual content. Users aim their personal device’s camera at the target display which then appears in live video shown in the viewfinder. To select an item, users take a picture which is analyzed to determine the targeted region. We further extended this approach to multiple displays by using a centralized component serving as gateway to the display environment. In Tap & Drop we refined this prototype to support real-time feedback. Instead of taking pictures, users can now aim their mobile device at the display resulting and start interacting immediately. In doing so, we broke the rigid sequential interaction of content selection and content manipulation. Both prototypes allow for (1) connections in a non-modal way (i.e., aim at the display and start interacting with it) from the user’s point of view and (2) fully flexible environments (i.e., the mobile device tracks itself with respect to displays in the environment). However, the wide-angle lenses and thus greater field of views of current mobile devices still do not allow for variable distances. In Touch Projector, we overcome this limitation by introducing zooming in combination with temporarily freezing the video image. Based on our extensions to taxonomy of mobile device interaction on external displays, we created a refined model of interacting through the display for mobile use. It enables users to interact impromptu without explicitly establishing a connection to the target display (non-modal). As the mobile device tracks itself with respect to displays in the environment, the model further allows for full flexibility of the environment (i.e., displays can be re-arranged without affecting on the interaction). And above all, users can interact with external displays regardless of their actual size at variable distances without any loss of accuracy.Die steigende Verfügbarkeit von Bildschirmen hat zu deren Verbreitung in unserem Alltag geführt. Ferner sind mobile Geräte immer griffbereit und wurden bereits als Interaktionsgeräte für zusätzliche Bildschirme vorgeschlagen. Es wurden jedoch nur Eingabemechanismen berücksichtigt ohne näher auf drei weitere Faktoren in Umgebungen mit mehreren Bildschirmen einzugehen: (1) Beide Geräte müssen verbunden werden (Modalität). (2) Bildschirme können in solchen Umgebungen umgeordnet werden (Flexibilität). (3) Monitore können außer Reichweite sein (Distanz). Wir streben an, die Probleme, die durch diese Eigenschaften auftreten, zu lösen. Das übergeordnete Ziel ist ein Interaktionsmodell, das einen nicht-modalen Verbindungsaufbau für spontane Verwendung von Bildschirmen in solchen Umgebungen, (2) Interaktion auf und zwischen Bildschirmen in flexiblen Umgebungen, und (3) Interaktionen in variablen Distanzen erlaubt. Wir stellen ein Modell (Interaktion durch den Bildschirm) vor, mit dem Benutzer mit entfernten Inhalten in direkter und absoluter Weise auf ihrem Mobilgerät interagieren können. Um die Effekte der hinzugefügten Charakteristiken besser zu verstehen, haben wir zwei Prototypen für unterschiedliche Distanzen implementiert: LucidDisplay erlaubt Benutzern ihr mobiles Gerät auf einen größeren, sekundären Bildschirm zu legen. Gegensätzlich dazu ermöglicht MobileVue die Interaktion mit einem zusätzlichen Monitor in einer gewissen Entfernung. In beiden Prototypen haben wir dann die Effekte der verbleibenden zwei Kriterien (d.h. Modalität des Verbindungsaufbaus und Flexibilität der Umgebung) analysiert. Mit den in dieser ersten Phase erhaltenen Ergebnissen haben wir Shoot & Copy entworfen. Dieser Prototyp erlaubt die Erkennung von Bildschirmen einzig über deren visuellen Inhalt. Benutzer zeigen mit der Kamera ihres Mobilgeräts auf einen Bildschirm dessen Inhalt dann in Form von Video im Sucher dargestellt wird. Durch die Aufnahme eines Bildes (und der darauf folgenden Analyse) wird Inhalt ausgewählt. Wir haben dieses Konzept zudem auf mehrere Bildschirme erweitert, indem wir eine zentrale Instanz verwendet haben, die als Schnittstelle zur Umgebung agiert. Mit Tap & Drop haben wir den Prototyp verfeinert, um Echtzeit-Feedback zu ermöglichen. Anstelle der Bildaufnahme können Benutzer nun ihr mobiles Gerät auf den Bildschirm richten und sofort interagieren. Dadurch haben wir die strikt sequentielle Interaktion (Inhalt auswählen und Inhalt manipulieren) aufgebrochen. Beide Prototypen erlauben bereits nicht-modale Verbindungsmechanismen in flexiblen Umgebungen. Die in heutigen Mobilgeräten verwendeten Weitwinkel-Objektive erlauben jedoch nach wie vor keine variablen Distanzen. Mit Touch Projector beseitigen wir diese Einschränkung, indem wir Zoomen in Kombination mit einer vorübergehenden Pausierung des Videos im Sucher einfügen. Basierend auf den Erweiterungen der Klassifizierung von Interaktionen mit zusätzlichen Bildschirmen durch mobile Geräte haben wir ein verbessertes Modell (Interaktion durch den Bildschirm) erstellt. Es erlaubt Benutzern spontan zu interagieren, ohne explizit eine Verbindung zum zweiten Bildschirm herstellen zu müssen (nicht-modal). Da das mobile Gerät seinen räumlichen Bezug zu allen Bildschirmen selbst bestimmt, erlaubt unser Modell zusätzlich volle Flexibilität in solchen Umgebungen. Darüber hinaus können Benutzer mit zusätzlichen Bildschirmen (unabhängig von deren Größe) in variablen Entfernungen interagieren

Gaze+touch vs. touch: what’s the trade-off when using gaze to extend touch to remote displays?

Direct touch input is employed on many devices, but it is inherently restricted to displays that are reachable by the user. Gaze input as a mediator can extend touch to remote displays - using gaze for remote selection, and touch for local manipulation - but at what cost and benefit? In this paper, we investigate the potential trade-off with four experiments that empirically compare remote Gaze+touch to standard touch. Our experiments investigate dragging, rotation, and scaling tasks. Results indicate that Gaze+touch is, compared to touch, (1) equally fast and more accurate for rotation and scaling, (2) slower and less accurate for dragging, and (3) enables selection of smaller targets. Our participants confirm this trend, and are positive about the relaxed finger placement of Gaze+touch. Our experiments provide detailed performance characteristics to consider for the design of Gaze+touch interaction of remote displays. We further discuss insights into strengths and drawbacks in contrast to direct touch

Ultraviolet Observations of Supernovae

The motivations to make ultraviolet (UV) studies of supernovae (SNe) are reviewed and discussed in the light of the results obtained so far by means of IUE and HST observations. It appears that UV studies of SNe can, and do lead to fundamental results not only for our understanding of the SN phenomenon, such as the kinematics and the metallicity of the ejecta, but also for exciting new findings in Cosmology, such as the tantalizing evidence for "dark energy" that seems to pervade the Universe and to dominate its energetics. The need for additional and more detailed UV observations is also considered and discussed.Comment: 10 pages, 5 figures - Invited talk at the "Supernova 1987A: 20 Years after: Supernovae and Gamma-Ray Bursters" Conference, February 19-23, 2007, Aspen, CO, (AIP Conf. Proc.), eds. S. Immler, R. McCray and K.W. Weiler, in press. Slightly revised version that clarifies some confusing statement