Biomechanical model for simulating impacts against protective padding of sport facility     

Pier Paolo Valentini  Ettore Pennestrì  Leonardo Quattrociocchi 《Sports Engineering》2016,19(1):47-57

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Lights,Camera, Action: Facilitating the Design and Production of Effective Instructional Videos     

Terry Di Paolo  Jenny S. Wakefield  Leila A. Mills  Laura Baker 《TechTrends》2017,61(5):452-460

This paper outlines a rudimentary process intended to guide faculty in K-12 and higher education through the steps involved to produce video for their classes. The process comprises four steps: planning, development, delivery and reflection. Each step is infused with instructional design information intended to support the collaboration between instructional support staff and faculty to produce video that will be meaningful to students and support their success in a class. In outlining this approach, the paper also explores technological and pedagogical considerations related to each of these steps that can help faculty and staff determine how best to incorporate video into online classes. Finally, supported by research on best video practices and with examples from our own experiences as instructional designers and instructors, the paper outlines how these steps relate to four broad categories of video: introduce, model, explain/inform and feedback.  相似文献   

The Pendulum: From Constrained Fall to the Concept of Potential     

Fabio Bevilacqua  Lidia Falomo  Lucio Fregonese  Enrico Giannetto  Franco Giudice  Paolo Mascheretti 《Science & Education》2006,15(6):553-575

Kuhn underlined the relevance of Galileo’s gestalt switch in the interpretation of a swinging body from constrained fall to time metre. But the new interpretation did not eliminate the older one. The constrained fall, both in the motion of pendulums and along inclined planes, led Galileo to the law of free fall. Experimenting with physical pendulums and assuming the impossibility of perpetual motion Huygens obtained a law of conservation of vis viva at specific positions, beautifully commented by Mach. Daniel Bernoulli generalised Huygens results introducing the concept of potential and the related independence of the ‘work’ done from the trajectories (paths) followed: vis viva conservation at specific positions is now linked with the potential. Feynman’s modern way of teaching the subject shows striking similarities with Bernoulli’s approach. A number of animations and simulations can help to visualise and teach some of the pendulum’s interpretations related to what we now see as instances of energy conservation.  相似文献   

Deductive teaching from computer science foundations     

Paolo Rocchi 《Education and Information Technologies》1998,3(1):41-50

Various problems concerning the teaching of informatics arise from the foundations of computer science. Difficulties in terminology, in lesson definition, in the introduction to topics are examples of substantial and they are not psychological or expressive problems. The foundations are officially acknowledged as an open problem and they give rise to incomplete and mnemomic computer science learning. They do not allow the student to be aware of informatics themes. They subsequently inhibit programming, systems design, research and many other activities. This paper discusses the results of theoretical research on the foundations carried out at IBM. This facititates deductive teaching and improves students preparation on the basic contents and on all the other themes of computer science. The early lessons of a high-school course are outlined. © 1998 IFIP, published by Chapman & Hall Ltd  相似文献   

e-university: a cross-case study in four Italian universities     

Patrizia Ghislandi  Paolo Calidoni  Floriana Falcinelli  Cesare Scurati 《British journal of educational technology : journal of the Council for Educational Technology》2008,39(3):443-455

This paper describes the aims, the methods, the stages and the results of the research project 'e-University. Information and communication technologies (ICTs) as a factor of change in Italian universities', undertaken between 2003 and 2006 by the Universities of Trento, Perugia and Sassari and the Catholic University of Milan.
The characteristics of the four institutions' subjects and objects of the investigation are analysed as case studies and then compared as a cross-case study in the light of the factors that we feel constitute the main areas of concern in the four institutions as to the implementation of ICTs in the teaching/learning process, ie, the characteristics of the governance strategic plan, the choices relating to technology and the choices related to pedagogy. The paper describes the collaborative effort characterising the community of researchers through the different stages of the research. It also analyses how the individual features of each university—relating to its history, the number of students, the range of faculties, the diffusion of e-learning, the driving factors for innovation, the institution's policies—have fostered a lively and fruitful discussion between different view points, thus engendering deeper reflections for each context.  相似文献   

Biorthogonal wavelet trees in the classification of embedded signal classes for intelligent sensors using machine learning applications     

Paolo Mercorelli 《Journal of The Franklin Institute》2007,344(6):813-829

The paper deals with a method of constructing orthonormal bases of coordinates which maximize, through redundant dictionaries (frames) of biorthogonal bases, a class separability index or distances among classes. The method proposes an algorithm which consists of biorthogonal expansions over two redundant dictionaries. Embedded classes are often present in multiclassification problems. It is shown how the biorthogonality of the expansion can really help to construct a coordinate system which characterizes the classes. The algorithm is created for training wavelet networks in order to provide an efficient coordinate system maximizing the Cross Entropy function between two complementary classes. Sine and cosine wavelet packets are basis functions of the network. Thanks to their packet structure, once selected the depth of the tree, an adaptive number of basis functions is automatically chosen. The algorithm is also able to carry out centering and dilation of the basis functions in an adaptive way. The algorithm works with a preliminary extracted feature through shrinkage technique in order to reduce the dimensionality of the problem. In particular, our attention is pointed out for time-frequency monitoring, detection and classification of transients in rail vehicle systems and the outlier problem. In the former case the goal is to distinguish transients as inrush current and no inrush current and a further distinction between the two complementary classes: dangerous inrush current and no dangerous inrush current. The proposed algorithm is used on line in order to recognize the dangerous transients in real time and thus shut-down the vehicle. The algorithm can also be used in a general application of the outlier detection. A similar structure is used in developed algorithms which are currently integrated in the inferential modeling platform of the unit responsible for Advanced Control and Simulation Solutions within ABB's (Asea Brown Boveri) industry division. It is shown how impressive and rapid performances are achieved with a limited number of wavelets and few iterations. Real applications using real measured data are included to illustrate and analyze the effectiveness of the proposed method.  相似文献   

Chemicals in the Field - Edmund Russell,War and Nature: Fighting Humans and Insects with Chemicals from World War I to Silent Spring     

Palladino  Paolo  Mitman  Gregg  Jansen  Sarah 《Metascience》2003,12(1):3-23

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Self-citations as strategic response to the use of metrics for career decisions     

Marco Seeber  Mattia Cattaneo  Michele Meoli  Paolo Malighetti 《Research Policy》2019,48(2):478-491

There is limited knowledge on the extent to which scientists may strategically respond to metrics by adopting questionable practices, namely practices that challenge the scientific ethos, and the individual and contextual factors that affect their likelihood. This article aims to fill these gaps by studying the opportunistic use of self-citations, i.e. citations of one’s own work to boost metric scores. Based on sociological and economic literature exploring the factors driving scientists’ behaviour, we develop hypotheses on the predictors of strategic increase in self-citations. We test the hypotheses in the Italian Higher Education system, where promotion to professorial positions is regulated by a national habilitation procedure that considers the number of publications and citations received. The sample includes 886 scientists from four of science’s main disciplinary sectors, employs different metrics approaches, and covers an observation period beginning in 2002 and ending in 2014. We find that the introduction of a regulation that links the possibility of career advancement to the number of citations received is related to a strong and significant increase in self-citations among scientists who can benefit the most from increasing citations, namely assistant professors, associate professors and relatively less cited scientists, and in particular among social scientists. Our findings suggest that while metrics are introduced to spur virtuous behaviours, when not properly designed they favour the usage of questionable practices.  相似文献   

It's never too late: Funding dynamics and self pledges in reward-based crowdfunding     

Paolo Crosetto  Tobias Regner 《Research Policy》2018,47(8):1463-1477

Crowdfunding recently emerged as an alternative funding channel for entrepreneurs. We use pledge-level data from Startnext, the biggest German platform, to gain insights on funding dynamics and pledgers’ motivations. We find that the majority of projects that eventually succeed are not on a successful track at 75% of their funding period. These late successes are boosted by information cascades during the final 25% of the funding duration. We conclude – in contrast with earlier literature – that project success is only partially path-dependent. While early pledges do anticipate project success, a lack of them does not necessarily mean that projects will fail. Interviews and questionnaire responses indicate that projects’ communication efforts play a role in making severely under track projects succeed eventually. Moreover, our dataset uniquely allows us to quantify the extent of self funding. Self pledges account for about 10% of all initial pledges and 9% of all pledges that secure funding. Nonetheless, the late surges at severely under track projects are mostly driven by external funders. Furthermore, we find no evidence of subsequent herding triggered by self pledges.  相似文献   

Is microrheometry affected by channel deformation?     

Francesco Del Giudice  Francesco Greco  Paolo Antonio Netti  Pier Luca Maffettone 《Biomicrofluidics》2016,10(4)

Microrheometry is very important for exploring rheological behaviours of several systems when conventional techniques fail. Microrheometrical measurements are usually carried out in microfluidic devices made of Poly(dimethylsiloxane) (PDMS). Although PDMS is a very cheap material, it is also very easy to deform. In particular, a liquid flowing in a PDMS device, in some circumstances, can effectively deform the microchannel, thus altering the flow conditions. The measure of the fluid relaxation time might be performed through viscoelasticity induced particle migration in microfluidics devices. If the channel walls are deformed by the flow, the resulting measured value of the relaxation time could be not reliable. In this work, we study the effect of channel deformation on particle migration in square-shaped microchannel. Experiments are carried out in several PolyEthylene Oxyde solutions flowing in two devices made of PDMS and Poly(methylmethacrylate) (PMMA). The relevance of wall rigidity on particle migration is investigated, and the corresponding importance of wall rigidity on the determination of the relaxation time of the suspending liquid is examined.  相似文献