The Wisdom of Practice Meets the Pursuit of Scientific Inquiry. A Response to Scientifically Based Research and Teacher Agency: Combating \u27Conspiracies of Certainty\u27

Stemhagen and Nomi argued that the influence of many contemporary forms of education research, especially scientifically based research, inevitably position teachers as problems rather than as active agents whose judgement is indivisible from the activity of teaching and learning. We share the authors’ intuitions and concerns about the divide between research and teaching but also wonder if there remains another way into some of the concerns they raise. We start with a different question but one we think is fundamental to Stemhagen and Nomi’s critique: How do the findings of empirical research make their way into the work of teaching? By answering this question, we hope to reframe the authors’ concerns and reconsider their recommendation that teachers become participatory action researchers. It is distressing that practitioners and researchers have not yet found ways (despite the insights of John Dewey and other theorist and practitioners over more than a century) to substantively account for each others’ growing understanding because both the wisdom of practice and the pursuit of scientific insight are central to the effective and generative practice of educating children and adults

Blickpunktabhängige Computergraphik

Contemporary digital displays feature multi-million pixels at ever-increasing refresh rates. Reality, on the other hand, provides us with a view of the world that is continuous in space and time. The discrepancy between viewing the physical world and its sampled depiction on digital displays gives rise to perceptual quality degradations. By measuring or estimating where we look, gaze-contingent algorithms aim at exploiting the way we visually perceive to remedy visible artifacts. This dissertation presents a variety of novel gaze-contingent algorithms and respective perceptual studies. Chapter 4 and 5 present methods to boost perceived visual quality of conventional video footage when viewed on commodity monitors or projectors. In Chapter 6 a novel head-mounted display with real-time gaze tracking is described. The device enables a large variety of applications in the context of Virtual Reality and Augmented Reality. Using the gaze-tracking VR headset, a novel gaze-contingent render method is described in Chapter 7. The gaze-aware approach greatly reduces computational efforts for shading virtual worlds. The described methods and studies show that gaze-contingent algorithms are able to improve the quality of displayed images and videos or reduce the computational effort for image generation, while display quality perceived by the user does not change.Moderne digitale Bildschirme ermöglichen immer höhere Auflösungen bei ebenfalls steigenden Bildwiederholraten. Die Realität hingegen ist in Raum und Zeit kontinuierlich. Diese Grundverschiedenheit führt beim Betrachter zu perzeptuellen Unterschieden. Die Verfolgung der Aug-Blickrichtung ermöglicht blickpunktabhängige Darstellungsmethoden, die sichtbare Artefakte verhindern können. Diese Dissertation trägt zu vier Bereichen blickpunktabhängiger und wahrnehmungstreuer Darstellungsmethoden bei. Die Verfahren in Kapitel 4 und 5 haben zum Ziel, die wahrgenommene visuelle Qualität von Videos für den Betrachter zu erhöhen, wobei die Videos auf gewöhnlicher Ausgabehardware wie z.B. einem Fernseher oder Projektor dargestellt werden. Kapitel 6 beschreibt die Entwicklung eines neuartigen Head-mounted Displays mit Unterstützung zur Erfassung der Blickrichtung in Echtzeit. Die Kombination der Funktionen ermöglicht eine Reihe interessanter Anwendungen in Bezug auf Virtuelle Realität (VR) und Erweiterte Realität (AR). Das vierte und abschließende Verfahren in Kapitel 7 dieser Dissertation beschreibt einen neuen Algorithmus, der das entwickelte Eye-Tracking Head-mounted Display zum blickpunktabhängigen Rendern nutzt. Die Qualität des Shadings wird hierbei auf Basis eines Wahrnehmungsmodells für jeden Bildpixel in Echtzeit analysiert und angepasst. Das Verfahren hat das Potenzial den Berechnungsaufwand für das Shading einer virtuellen Szene auf ein Bruchteil zu reduzieren. Die in dieser Dissertation beschriebenen Verfahren und Untersuchungen zeigen, dass blickpunktabhängige Algorithmen die Darstellungsqualität von Bildern und Videos wirksam verbessern können, beziehungsweise sich bei gleichbleibender Bildqualität der Berechnungsaufwand des bildgebenden Verfahrens erheblich verringern lässt

Managing for change: October 11, 1989

Bi-weekly newsletter of University Hospital's Change Project, provided to managers at the hospital

Iodine content in bulk biomass of wild-harvested and cultivated edible seaweeds: Inherent variations determine species-specific daily allowable consumption

This study represents a large-scale investigation into iodine contents in three commercially important and edible seaweed species from the North Atlantic: the brown algae Saccharina latissima and Alaria esculenta, and the red alga Palmaria palmata. Variability among and within species were explored in terms of temporal and spatial variations in addition to biomass source. Mean iodine concentration in bulk seaweed biomass was speciesspecific: Saccharina > Alaria > Palmaria. Iodine contents of Saccharina biomass were similar between years and seasons, but varied significantly between sampling locations and biomass sources. In Alaria and Palmaria, none of the independent variables examined contributed significantly to the small variations observed. Our data suggest that all three species are rich sources of iodine, and only 32, 283, or 2149 mg dry weight of unprocessed dry biomass of Saccharina, Alaria, or Palmaria, respectively, meets the recommended daily intake levels for most healthy humans.publishedVersio

Optical Gaze Tracking with Spatially-Sparse Single-Pixel Detectors

Gaze tracking is an essential component of next generation displays for virtual reality and augmented reality applications. Traditional camera-based gaze trackers used in next generation displays are known to be lacking in one or multiple of the following metrics: power consumption, cost, computational complexity, estimation accuracy, latency, and form-factor. We propose the use of discrete photodiodes and light-emitting diodes (LEDs) as an alternative to traditional camera-based gaze tracking approaches while taking all of these metrics into consideration. We begin by developing a rendering-based simulation framework for understanding the relationship between light sources and a virtual model eyeball. Findings from this framework are used for the placement of LEDs and photodiodes. Our first prototype uses a neural network to obtain an average error rate of 2.67{\deg} at 400Hz while demanding only 16mW. By simplifying the implementation to using only LEDs, duplexed as light transceivers, and more minimal machine learning model, namely a light-weight supervised Gaussian process regression algorithm, we show that our second prototype is capable of an average error rate of 1.57{\deg} at 250 Hz using 800 mW.Comment: 10 pages, 8 figures, published in IEEE International Symposium on Mixed and Augmented Reality (ISMAR) 202

Detraining Effects on Musculoskeletal Parameters in Early Postmenopausal Osteopenic Women: 3-Month Follow-Up of the Randomized Controlled ACTLIFE Study

Periods of absence from supervised group exercise while maintaining physical activity might be a frequent pattern in adults’ exercise habits. The aim of the present study was to determine detraining effects on musculoskeletal outcomes after a 3-month detraining period in early post-menopausal, osteopenic women. Due to the COVID-19 pandemic, we terminated the 18-month randomized controlled ACTLIFE exercise intervention immediately after the 13-month follow-up assessment. This put an abrupt stop to the high-intensity aerobic and resistance group exercise sessions undertaken three times per week by the exercise group (EG: n = 27) and the gentle exercise program performed once per week for the attention control group (CG: n = 27); but both groups were permitted to conduct individual outdoor activity for the 3-month lock-down period. Study endpoints were lean body mass (LBM), bone mineral density (BMD) at the lumbar spine (LS), maximum hip-/leg extension strength and power. Detraining-induced reductions of LBM, hip/leg strength and power (but not BMD-LS) were significantly greater (p < 0.001 to p = 0.044) compared with the CG. Significant exercise effects, i.e. differences between EG and CG, present after 13 months of exercise, were lost after 3 months of detraining for LBM (p = 0.157) and BMD-LS (p = 0.065), but not for strength (p < 0.001) and power (p < 0.001). Of note, self-reported individual outdoor activities and exercise increased by about 40% in both groups during the lock-down period. Three months’ absence from a supervised group exercise protocol resulted in considerable detraining effects for musculoskeletal parameters. Thus, exercise programs for adults should be continuous rather than intermittent. Trial registration number: ClinicalTrials.gov: NCT04420806, 06.05.2020

Optimizing Apparent Display Resolution Enhancement for Arbitrary Videos

Display resolution is frequently exceeded by available image resolution. Recently, apparent display resolution enhancement techniques (ADRE) have demonstrated how characteristics of the human visual system can be exploited to provide super-resolution on high refresh rate displays. In this paper we address the problem of generalizing the apparent display resolution enhancement technique to conventional videos of arbitrary content. We propose an optimization-based approach to continuously translate the video frames in such a way that the added motion enables apparent resolution enhancement for the salient image region. The optimization takes the optimal velocity, smoothness and similarity into account to compute an appropriate trajectory. Additionally, we provide an intuitive user interface which allows to guide the algorithm interactively and preserve important compositions within the video. We present a user study evaluating apparent rendering quality and demonstrate versatility of our method on a variety of general test scenes.Aktuelle Kameras sind in der Lage, Videos mit sehr hoher Auflösung aufzunehmen (> 4K Pixel). Monitore, Fernseher und Projektoren haben jedoch meist eine deutlich niedrigere Auflösung (FullHD). Bei der Darstellung hochaufgelöster Videos auf diesen Geräten gehen durch das nötige Herrunterrechnen der Videodaten feine Details verloren, z.B. Haare oder die Pigmentierung von Oberflächenmaterialien. Es wird ein Verfahren präsentiert, welches die Darstellung eines beliebigen Videos mit einer Auflösung ermöglicht, die perzeptuell höher ist als die Auflösung des Ausgabegerätes