Vernetztes Wissen

Innerhalb der Gedächtnisinstitutionen Bibliothek, Museum und Archiv gibt es je eigene Beschreibungsmodelle der beherbergten Objekte und Materialien. Für eine genauere bibliographische Erschließung wurde im Bibliotheksbereich das von Benutzerbedürfnissen ausgehende, statische Modell "Functional Requirements for Bibliographic Records" (FRBR) geschaffen, dessen ungenauer "Werk"-Begriff ebenso thematisiert wird wie die schwer zu realisierende Übertragbarkeit des Modells auf Nicht-Buchmaterialien. Die Museumswelt orientiert die Darstellung ihrer Bestände am CIDOC Conceptual Reference Model (CRM), das sich hinsichtlich der Beschreibung heterogener Museumsobjekte, also Artefakten künstlerischer und intellektueller Gestaltung, als hilfreich erwiesen hat. In gegenseitigem Austausch zwischen IFLA und ICOM wurde FRBR mit CRM harmonisiert. Das Ergebnis, FRBROO (Objektorientiertes FRBR), zeigt seine Vorzüge zum einen in einer strengeren Interpretation der Entitäten der Gruppe 1 des FRBR-Modells und zum anderen in einer genaueren Abbildung von Prozessen bzw. Ereignissen. Beispiele zum Anwendungsbezug von FRBROO zeigen dessen Zugewinn für die wissenschaftliche Erschließung hand-, druck- und online-schriftlicher Quellen, Werken der Darstellenden Kunst, Landkarten und Musikalien innerhalb einer CRM-basierten Datenbank.Each of the three memory institutions library, museum and archive has developed his own conceptual model for their holdings of objects and materials. The static model "Functional Requirements for Bibliographic Records" (FRBR) was established for a more precise bibliographic indexing in libraries. But this model lacks a detailed concept of the entity "work" and is not that much useful for non-book materials. The CIDOC Conceptual Reference Model (CRM) is the central data model for museums; it is very appropriate for the heterogeneous mass of museum objects and artefacts which are all products of an artistic or intellectual creation. IFLA and ICOM harmonized FRBR with CRM in mutual exchange. The outcome, FRBROO (object-oriented FRBR), shows advantages in terms of a more strict interpretation of the group 1-entities of FRBR, and also in a closer illustration of processes and events. Examples of an applied approach of FRBROO show its gain in scientific indexing of manuscripts, prints, online publications, performing arts, maps, and musical works within a CRM-based data base

Students´ reading ability moderates the effects of teachers´ beliefs on students´ reading progress

Teachers’ beliefs about teaching have been found to affect students’ learning growth. The aim of this study was to investigate effects of teachers’ constructivist and direct-transmissive beliefs on learners’ reading progress and whether these effects are influenced by prior student achievement. We measured constructivist and direct-transmissive beliefs of 29 teachers and the progress in reading fluency and reading comprehension of their students (N = 568) at eight points of measurement over one school year. Results of three-level latent growth curve modeling revealed that teachers’ constructivist beliefs were positively related to learners’ progress in reading fluency but had no general effect on growth in reading comprehension. Nevertheless, the relation between constructivist beliefs and individual learners’ progress in reading comprehension was affected by students’ level of ability. Teachers with stronger constructivist beliefs effected higher learning growth for high ability compared to low ability learners. No effects were found for direct-transmissive beliefs. Using longitudinal modelling of student learning, this study adds a more differentiated view to findings concerning the effects of teacher beliefs. Results show that effects vary depending on subject of learning (fluency vs. comprehension), and that effects of teacher beliefs may depend on students’ level of ability

Learning to reach and reaching to learn: a unified approach to path planning and reactive control through reinforcement learning

The next generation of intelligent robots will need to be able to plan reaches. Not just ballistic point to point reaches, but reaches around things such as the edge of a table, a nearby human, or any other known object in the robot’s workspace. Planning reaches may seem easy to us humans, because we do it so intuitively, but it has proven to be a challenging problem, which continues to limit the versatility of what robots can do today. In this document, I propose a novel intrinsically motivated RL system that draws on both Path/Motion Planning and Reactive Control. Through Reinforcement Learning, it tightly integrates these two previously disparate approaches to robotics. The RL system is evaluated on a task, which is as yet unsolved by roboticists in practice. That is to put the palm of the iCub humanoid robot on arbitrary target objects in its workspace, start- ing from arbitrary initial configurations. Such motions can be generated by planning, or searching the configuration space, but this typically results in some kind of trajectory, which must then be tracked by a separate controller, and such an approach offers a brit- tle runtime solution because it is inflexible. Purely reactive systems are robust to many problems that render a planned trajectory infeasible, but lacking the capacity to search, they tend to get stuck behind constraints, and therefore do not replace motion planners. The planner/controller proposed here is novel in that it deliberately plans reaches without the need to track trajectories. Instead, reaches are composed of sequences of reactive motion primitives, implemented by my Modular Behavioral Environment (MoBeE), which provides (fictitious) force control with reactive collision avoidance by way of a realtime kinematic/geometric model of the robot and its workspace. Thus, to the best of my knowledge, mine is the first reach planning approach to simultaneously offer the best of both the Path/Motion Planning and Reactive Control approaches. By controlling the real, physical robot directly, and feeling the influence of the con- straints imposed by MoBeE, the proposed system learns a stochastic model of the iCub’s configuration space. Then, the model is exploited as a multiple query path planner to find sensible pre-reach poses, from which to initiate reaching actions. Experiments show that the system can autonomously find practical reaches to target objects in workspace and offers excellent robustness to changes in the workspace configuration as well as noise in the robot’s sensory-motor apparatus

Distorted Voronoi languages

Förster M, Riedel F. Distorted Voronoi languages. Working Papers. Institute of Mathematical Economics. Vol 458. Bielefeld: Center for Mathematical Economics; 2011.In a recent paper, Jäger, Metzger, and Riedel (2011) study communication games of common interest when signals are simple and types complex. They characterize strict Nash equilibria as so-called Voronoi languages that consist of Voronoi tesselations of the type set and Bayesian estimators on the side of receivers. In this note, we introduce conflicts of interest in the same setting. We characterize strict Nash equilibria as distorted Voronoi languages that use all messages. For large conflicts, such informative equilibria need not exist. If the bias is sufficiently small, however, these equilibria do exist. This establishes the robustness of the results in Jäger, Metzger, and Riedel (2011) to biased interests. We finally give examples of strict Nash equilibria, one of them using simulations to illustrate an equilibrium with many messages and non-uniformly distributed types