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In this paper, two methodological perspectives are used to elaborate on the value of cognitive load theory (CLT) as a scientific
theory. According to the more traditional critical rationalism of Karl Popper, CLT cannot be considered a scientific theory
because some of its fundamental assumptions cannot be tested empirically and are thus not falsifiable. According to the structuralist
view of theories introduced by Joseph D. Sneed, a theory may be considered scientific even if it comprises nontestable fundamental
assumptions. Rather, the scientific value of a theory results from the holistic empirical content of the overall theory net
built around fundamental assumptions and from the successful applications of this theory net to explain and predict empirical
findings. This latter view is helpful to explicate some implicit methodological assumptions of CLT research and to avoid the
potential circularity of CLT’s fundamental assumptions. Additionally, the structuralist view of theories can be directly used
to derive a research agenda for the future development of CLT. 相似文献
73.
Gabriele Perozzi Denis Efimov Jean-Marc Biannic Laurent Planckaert 《Journal of The Franklin Institute》2018,355(12):4809-4838
The problem of position tracking of a mini drone subject to wind perturbations is investigated. The solution is based on a detailed unmanned aerial vehicle (UAV) model, with aerodynamic coefficients and external disturbance components, which is introduced in order to better represent the impact of the wind field. Then, upper bounds of wind-induced disturbances are characterized, which allow a sliding mode control (SMC) technique to be applied with guaranteed convergence properties. The peculiarity of the considered case is that the disturbance upper bounds depend on the control amplitude itself (i.e. the system is nonlinear in control), which leads to a new procedure for the control tuning presented in the paper. The last part of the paper is dedicated to the analysis and reduction of chattering effects, as well as investigation of rotor dynamics issues. Conventional SMC with constant gains, proposed first order SMC, and proposed quasi-continuous SMC are compared. Nonlinear UAV simulator, validated through in-door experiments, is used to demonstrate the effectiveness of the proposed controls. 相似文献
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Marcel Verhoeven M. Bjørn von Rimscha Isabelle Krebs Gabriele Siegert Christoph Sommer 《媒体管理杂志》2018,20(1):51-77
Research on media success factors is a fragmented field. Definitions, measures, and methods vary, and findings are often inconsistent. In an attempt to fill this perceived research gap, we distilled generic success factors of media products from the literature. Guided by theory and empirical findings, these factors were aggregated to complex concepts, building blocks of success that we further investigated in an exploratory qualitative study. We found that the building blocks are applicable to all types of media, independent of seriality and content types of media products. Subsequently the research question of this article is: Which building blocks of success are most important for media products? To answer this question, we conducted an online survey of 255 media professionals in print, audio-visual, and online media in Austria, Germany and Switzerland. To analyze our data, we deployed qualitative comparative analysis, a method based on set theory that is suitable to investigate complex causality. We conclude that four building blocks are necessary for success: “good” distribution, environmental orientation, form/design, and human resources are preconditions for achieving success in terms of audience market share. In addition, three patterns emerge in the sufficient paths (combinations of building blocks) to success. Which route to success a media product shows can be related to the width of its topical scope and the corresponding projected audience size. 相似文献
76.
Gabriele Wulf 《Journal of sports sciences》2016,34(13):1293-1295
In this invited response to a Letter to the Editor by Carson, Collins, and Toner (2015), I comment on various issues raised by the authors. I highlight the broad range of tasks and dependent measures used in studies comparing the effectiveness of external versus internal foci of attention. These studies – many of which involved sport skills – have consistently found performance or learning benefits when an external focus was adopted. There is no convincing evidence that performers’ preferences, or their familiarity with a certain focus, have a moderating effect. Anecdotal evidence reported by coaches who have compared the two types of foci is consistent with research findings. An external focus presumably promotes functional connectivity and contributes to goal-action coupling. 相似文献
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An archaeological excavation has been carried out at Pisa (Italy), unearthing an ancient metallurgical workshop. Since archaeological burnt materials provide important records of direction and intensity of the Earth's magnetic field in the past and they can be used to better improve geomagnetic secular variation curves (SVCs), an archaeomagnetic study has been performed. This small copper-alloy furnace presents a circular concave shape covered with a thin layer of mortar, with some traces of heated clay surrounding the feature that confirms the high temperature reached inside it. Archaeological context dating points to the last firing of the furnace between the last quarter of the 13th century and the first quarter of 14th century AD, when then the metallurgical workshop was transformed in a warehouse. Archaeomagnetic sampling has been performed using the modified Thellier method, by collecting several, large and independently oriented aliquots of heated clay, forming the bottom part of the circular wall of the structure. Laboratory treatments have been conducted at the IGG-CNR ARCHEO_LAB (Pisa, Italy) and at St. Maur Palaeomagnetic laboratory (Paris, France). Analytical measurements of the thermo-remanent magnetization index acquired from the samples have been performed using a large cell induction magnetometer for large samples, and the characteristic remanent magnetization (ChRM) has been successfully isolated after an alternate field demagnetization cleaning procedure for each sample. The final mean archaeomagnetic direction has been calculated at sampling site (D = 6.9°; I = 52.8°; N = 9; k = 305; α95 = 2.6°) following the Fisher Statistics, and it exhibits a perfect agreement with some coeval already published directions obtained from Mt. Arso lava flows, these latter being an important anchor point in the preliminary Italian secular variation curve. Comparison with the preliminary Italian SVC, the French SVC and the SCHA.DIF.3K archaeomagnetic regional model have permitted to define an archaeomagnetic absolute age confirming the conventional archaeological age, underlining the importance of this result into the Italian archaeomagnetic data set. 相似文献