545 research outputs found

    Embodied learning at a distance: From sensory-motor experience to constructing and understanding a sine graph

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    Educational technologies develop quickly. Which functions of face-to-face education can be substituted by technology for distance learning? One of the risks of online education is the lack of embodied interactions. We investigate what embodied interactive technologies might offer for teaching trigonometry when learning at a distance. In a multiple case study, we analyze the potential of embodied action-based design for fostering conceptual understanding of a sine graph. It appears that independent learning with tablet-based activities leads to acquiring new sensory-motor coordinations. Some students include these new embodied experiences into mathematical discourse and trigonometry problem solving themselves, while others still need some support from a teacher. However, distantly acquired embodied experiences can be easily recalled in a few days after learning and serve well as a substrate for further conceptualization and problem-solving. The results speak for a clear contribution that embodied design might provide for grounding conceptual understanding in distance learning. However, we expect embodied design to be particularly helpful in a blended learning format

    High Intensity Low Temperature (HILT) performance of space concentrator GaInP/GaInAs/Ge MJ SCs

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    In the work, the results of an investigation of GaInP/GaInAs/Ge MJ SCs intended for converting concentrated solar radiation, when operating at low temperatures (down to -190 degrees C) are presented. A kink of the cell I-V characteristic has been observed in the region close to V-oc starting from -20 degrees C at operation under concentrated sunlight. The causes for its occurrence have been analyzed and the reasons for formation of a built-in potential barrier for majority charge carriers at the n-GaInP/n-Ge isotype hetero-interface are discussed. The effect of charge carrier transport in n-GaInP/n-p Ge heterostructures on MJ SC output characteristics at low temperatures has been studied including EL technique

    Minimal deformations of the commutative algebra and the linear group GL(n)

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    We consider the relations of generalized commutativity in the algebra of formal series Mq(xi) M_q (x^i ) , which conserve a tensor Iq I_q -grading and depend on parameters q(i,k) q(i,k) . We choose the Iq I_q -preserving version of differential calculus on Mq M_q . A new construction of the symmetrized tensor product for Mq M_q -type algebras and the corresponding definition of minimally deformed linear group QGL(n) QGL(n) and Lie algebra qgl(n) qgl(n) are proposed. We study the connection of QGL(n) QGL(n) and qgl(n) qgl(n) with the special matrix algebra \mbox{Mat} (n,Q) containing matrices with noncommutative elements. A definition of the deformed determinant in the algebra \mbox{Mat} (n,Q) is given. The exponential parametrization in the algebra \mbox{Mat} (n,Q) is considered on the basis of Campbell-Hausdorf formula.Comment: 14 page

    AlGaAs/GaAs photovoltaic converters for high power narrowband radiation

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    AlGaAs/GaAs-based laser power PV converters intended for operation with high-power (up to 100 W/cm(2)) radiation were fabricated by LPE and MOCVD techniques. Monochromatic (lambda = 809 nm) conversion efficiency up to 60% was measured at cells with back surface field and low (x = 0.2) Al concentration 'window'. Modules with a voltage of 4 V and the efficiency of 56% were designed and fabricated

    Risk of sudden cardiac death in strength training

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    Physical activity is a generally accepted means of primary and secondary prevention of cardiovascular diseases, but in some cases, it can be a risk factor for cardiovascular events, including sudden cardiac death (SCD). Most studies analyze the relationship of cardiovascular events with the volume and general directions of exercise. Besides, a significant part of the guidelines and studies are devoted to the effects of aerobic exercise, while the importance of anaerobic exercise remains controversial. The review analyzes works devoted to the influence of strength training, such as weightlifting, bodybuilding, powerlifting, etc., on the cardiovascular system, as well as their relationship with SCD and other cardiovascular events. The design and contingent of the analyzed papers did not allow them to be systematized correctly. Therefore, the review is largely analytical in nature

    Optimization of roll calibration for flange shape rolling. Groove space

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    The most important component of any rolling mill is the calibration of the rolls. The ability to obtain a finished product of high quality at minimal cost depends on the right calibration. According to the previous experience and practice a large number of different calibrations for the flange profiles production are known. The universal 'concept of two-stage optimization', consisting of two successively carried out optimization stages developed in the Department of Metal Forming of the Ural Federal University in relation to optimization of the roll calibration for flange shape rolling is considered in this article. Common features of these shapes classification and their variation levels are identified and justified. This developed classification structure is the basis for the formation of spaces of groove schemes, due to which the groove space is formed. In the software implementation the groove space is represented as a 'groove database'. In the future this database will be used to form the space of calibration schemes that are fundamentally suitable for these shapes rolling. © Published under licence by IOP Publishing Ltd.The reported study was funded by RFBR according to the research project 20-38-90246

    Embodied collaboration to foster instrumental genesis in mathematics

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    As cognitive science reports joint action requiring tight intercorporeal coordination between two partners, we aim to evaluate the role of this coordination in computer-supported instrumental genesis for mathematics. In our dual eye-tracking design study we developed an embodied activity that potentially contributes to technologically extended problem solving in trigonometry. We tested three versions of the design: (a) individual sensorimotor enactment only, (b) individual and then collaborative enactments, and (c) individual enactment and then collaborative description followed by enactment. As our first case showed, the required sensorimotor coordination was developed but never used in the following problem solving when a student worked alone. In contrast, in both collaborative cases the relevant sensorimotor coordination became a part of instrumented action scheme. Future research is needed to investigate if intercorporeal coordination with the other is crucial for the transfer of sensorimotor coordination from their original source to instrumental activity in mathematics
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