62 research outputs found

    Progress Monitoring in Primary Education using Levumi: A Case Study

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    We present, as a case study, the web-based platform Levumi that enables teachers to easily monitor learning progressions of children with a focus on elementary skills in reading, writing, and mathematics. Curriculumbased measurements are used that can be administered economically in short time and - in many parts - in parallel for multiple children. The system is built around exchanging data between schools and educational research, such that data with high ecological validity can be collected anonymously in order to gain insights into learning processes and in turn offer improved tests for teachers. For this case study, the acceptance and use of the platform over the last years is evaluated with a focus on tests for reading abilities. The results show how that many users are integrating the system in their daily teaching, learning progressions can be assessed and that the data is even usable for validation purposes

    Correlation of pre-operative cancer imaging techniques with post-operative gross and microscopic pathology images

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    In this paper, different algorithms for volume reconstruction from tomographic cross-sectional pathology slices are described and tested. A tissue-mimicking phantom made with a mixture of agar and aluminium oxide was sliced at different thickness as per pathological standard guidelines. Phantom model was also virtually sliced and reconstructed in software. Results showed that shape-based spline interpolation method was the most precise, but generated a volume underestimation of 0.5%

    Graphen der Lernverlaufsdiagnostik interpretieren und anwenden - Leseförderung mit der Onlineverlaufsmessung Levumi

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    Viele Schüler mit sonderpädagogischem Förderbedarf entwickeln Schwierigkeiten im sprachlichen Bereich. Dies hat zur Folge, dass insbesondere der Leseerwerb einer pädagogischen Aufbereitung bedarf. In dieser pädagogischen Arbeit bietet der problemlösende Ansatz der Lernverlaufsdiagnostik (engl. Curriculum- Based Measurement) Lehrkrä%en eine Unterstützung bei der Überprüfung der Effektivität ihres Unterrichts durch kurze und leicht handhabbare Tests. Diese Unterstützung kann durch weiterführende Materialien (z. B. Interpretationshilfen, Fördermaterialien) bestärkt werden. Für eine erfolgreiche Etablierung der Lernverlaufsdiagnostik und der damit verbundenen computergestützten Testsysteme in der Praxis müssen die aus dem Schulsystem bedingten Anforderungen berücksichtigt werden. Dieser Beitrag thematisiert literaturbasiert die Chancen und Grenzen bei der Implementation der Lernverlaufsdiagnostik in der pädagogischen Praxis. Dafür werden digitale Testsysteme, die Perspektive der Lehrkrä%e sowie Schwierigkeiten bei der Interpretation von Lernverlaufsgraphen fokussiert betrachtet. Als Praxisbeispiel wird das Angebot der kostenlosen Onlineplattform Levumi (www.levumi.de), ihre Lernverlaufstests im Bereich Lesen, die Interpretation der Klassen- und Individualgraphen und Fördermaterialien vorgestellt. Damit sich der Ansatz der Lernverlaufsdiagnostik in Deutschland im inklusiven Schulsystem etablieren kann, müssen Barrieren durch Kosten oder einen fehlenden technischen Support abgebaut werden. Zusätzlich können adaptive Testsysteme die Leseförderung durch automatisierte Empfehlungen von Fördermaterialien, schülergerechte Rückmeldungen und Analysen der Kompetenzpro+le der Schüler den Unterricht bereichern

    Machine-learning-driven advanced characterization of battery electrodes

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    Materials characterization is fundamental to our understanding of lithium ion battery electrodes and their performance limitations. Advances in laboratory-based characterization techniques have yielded powerful insights into the structure–function relationship of electrodes, yet there is still far to go. Further improvements rely, in part, on gaining a deeper understanding of complex physical heterogeneities in the materials. However, practical limitations in characterization techniques inhibit our ability to combine data directly. For example, some characterization techniques are destructive, thus preventing additional analyses on the same region. Fortunately, artificial intelligence (AI) has shown great potential for achieving representative, 3D, multi-modal datasets by leveraging data collected from a range of techniques. In this Perspective, we give an overview of recent advances in lab-based characterization techniques for Li-ion electrodes. We then discuss how AI methods can combine and enhance these techniques, leading to substantial acceleration in our understanding of electrodes

    Adding Spin Functionality to Traditional Optoelectronics via Chiral Perovskite

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    Spin polarized current generation and injection into semiconductors at room temperature are key to enable a broader range of opto-spintronic functionalities, yet the inherent efficiency of spin injection across commonly used semiconductor-ferromagnet interfaces is limited. Here, we demonstrate efficient spin injection into commercially viable III-V light emitting diodes (LED) by integrating chiral halide perovskite layers with (AlxGa1-x)0.5In0.5P multiple quantum wells (MQW). Spin polarized current is injected via chirality induced spin selectivity (CISS) and the spin accumulation in the III-V semiconductor is detected via the emission of circularly polarized light with a degree of circular polarization of up to ~ 15%. X-ray photoemission spectroscopy (XPS) and transmission electron microscopy (TEM) cross sectional imaging indicate a pristine perovskite/III-V interface. These findings demonstrate chiral perovskite semiconductors transform well-developed semiconductor platforms to enable control over spin, charge, and light

    Levumi: A Web-Based Curriculum-Based Measruement to Monitor Learning Progress in Inclusive Classrooms

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    Our paper introduces and assesses the Levumi platform’s web-based assessment of reading fluency. One challenges of inclusive education is meeting the needs of the learners with special education needs (SEN). Children with SEN and other risk factors face an increased risk of failing in schools and manifesting academic and social problems over the time. Web-based curriculum-based measurement (CBM) can provide an effective tool to track progress of learners and limit such risks. In particular, it can ease the challenges of test administration in inclusive classrooms through automation and providing multiple difficulty levels without the need of different paper-forms. Furthermore, Levumi can help educators track children and thus provide support for learners. Levumi takes advantage of the strengths of web-based CBM to assess reading fluency in primary school students. We confirmed the reading fluency test’s test-retest reliability (n = 334), its ability to measure learning over time in individual learners with SEN (n = 8, across 14 MPs), and its applicability to learners with SEN (n = 300, including n = 46 with SEN). We evaluate Levumi’s overall usefulness in assessing different types of learners, and discuss its contributions to CBM research

    Catalysing sustainable fuel and chemical synthesis

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    Concerns over the economics of proven fossil fuel reserves, in concert with government and public acceptance of the anthropogenic origin of rising CO2 emissions and associated climate change from such combustible carbon, are driving academic and commercial research into new sustainable routes to fuel and chemicals. The quest for such sustainable resources to meet the demands of a rapidly rising global population represents one of this century’s grand challenges. Here, we discuss catalytic solutions to the clean synthesis of biodiesel, the most readily implemented and low cost, alternative source of transportation fuels, and oxygenated organic molecules for the manufacture of fine and speciality chemicals to meet future societal demands

    Strong Geometrical Effects in Submillimeter Selective Area Growth and Light Extraction of GaN Light Emitting Diodes on Sapphire.

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    Advanced semiconductor devices often utilize structural and geometrical effects to tailor their characteristics and improve their performance. We report here detailed understanding of such geometrical effects in the epitaxial selective area growth of GaN on sapphire substrates and utilize them to enhance light extraction from GaN light emitting diodes. Systematic size and spacing effects were performed side-by-side on a single 2" sapphire substrate to minimize experimental sampling errors for a set of 144 pattern arrays with circular mask opening windows in SiO2. We show that the mask opening diameter leads to as much as 4 times increase in the thickness of the grown layers for 20 μm spacings and that spacing effects can lead to as much as 3 times increase in thickness for a 350 μm dot diameter. We observed that the facet evolution in comparison with extracted Ga adatom diffusion lengths directly influences the vertical and lateral overgrowth rates and can be controlled with pattern geometry. Such control over the facet development led to 2.5 times stronger electroluminescence characteristics from well-faceted GaN/InGaN multiple quantum well LEDs compared to non-faceted structures

    Molecular Dynamics Simulation and Cryo-Electron Microscopy Investigation of AOT Surfactant Structure at the Hydrated Mica Surface

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    Structural properties of the anionic surfactant dioctyl sodium sulfosuccinate (AOT or Aerosol-OT) adsorbed on the mica surface were investigated by molecular dynamics simulation, including the effect of surface loading in the presence of monovalent and divalent cations. The simulations confirmed recent neutron reflectivity experiments that revealed the binding of anionic surfactant to the negatively charged surface via adsorbed cations. At low loading, cylindrical micelles formed on the surface, with sulfate head groups bound to the surface by water molecules or adsorbed cations. Cation bridging was observed in the presence of weakly hydrating monovalent cations, while sulfate groups interacted with strongly hydrating divalent cations through water bridges. The adsorbed micelle structure was confirmed experimentally with cryogenic electronic microscopy, which revealed micelles approximately 2 nm in diameter at the basal surface. At higher AOT loading, the simulations reveal adsorbed bilayers with similar surface binding mechanisms. Adsorbed micelles were slightly thicker (2.2–3.0 nm) than the corresponding bilayers (2.0–2.4 nm). Upon heating the low loading systems from 300 K to 350 K, the adsorbed micelles transformed to a more planar configuration resembling bilayers. The driving force for this transition is an increase in the number of sulfate head groups interacting directly with adsorbed cations
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