A driver model of a two-man bobsleigh

Up to now, the optimization of structural parameters affecting the performance of a bobsleigh has been carried out mainly on the basis of athletes’ feedback, thus leading to a series of small modifications without univocal guidelines. Even though on-track tests represent a basic step for the final tuning of the sled, experimentation does not seem to represent an appropriate tool to objectively determine the influence of such structural parameters on the overall performance. In fact, their effect can easily be masked by driving errors, changes in the ice surface conditions and temperature thus requiring repeated tests for achieving statistical evidence. For this reason, numerical analysis, carried out with a 3D model of the bobsled, turns out to be a privileged instrument to optimize bob design although limitations in the sled model (e.g. ice friction properties that still have to be fully understood) may affect the obtained results. However, such tool is able to provide useful indications only if a correct driver model is implemented. This work focuses on the development of a numerical model of a bobsleigh driver that aims at reproducing the driving behaviour of real-world cup drivers and is basically made up of two steps: the identification of the trajectory that allows minimizing run time and the determination of the driver’s inputs to exactly follow that trajectory. For comparison purposes, the simulated driver’s inputs are compared with recorded ones on Cesana Pariol Olympic track.     

College Students’ Perceptions About the Plausibility of Human-Induced Climate Change

Overcoming students’ misconceptions may be a challenge when teaching about phenomena such as climate change. Students tend to cite short-term weather effects as evidence to support or refute long-term climate transformations, which displays a fundamental misunderstanding about weather and climate distinctions. Confusion about weather and climate may also reflect student misunderstanding about deep time, a concept that spans several scientific content areas. This study examines the relationships between students’ understanding of deep time and their understandings of the distinctions between weather and climate, as well as how these understandings influence students’ perceptions about the plausibility of human-induced global climate change. Undergraduate students enrolled in an introductory science class on global climate change completed measures of their (a) understanding of distinctions between weather and climate, (b) knowledge of deep time, and (c) plausibility perceptions of human-induced climate change, both at the beginning and end of the course. The study includes comparison groups of similar students enrolled in introductory physical geography classes. Results revealed that greater knowledge of deep time and increased plausibility perceptions of human-induced climate change provide significant explanation of variance in students’ understanding of weather and climate distinctions. Furthermore, students achieve significantly increased understanding of weather and climate, even with brief instruction.     

Issues Related to the Restoration of Mirrors of the Wooden paliotto della chiesa del Santissimo Crocifisso all’Albergheria,Sicily (Italy)

In this work, the decision-making process involved in the restoration of the eighteenth century paliotto ligneo (wooden altar frontal) della chiesa del Santissimo Crocifisso all’Albergheria of Palermo is presented. Earlier research concerning mirror restoration was based on only a few case studies and the proposed techniques were not suitable for the artwork here. As a consequence, it was necessary to re-examine theories and protocols of modern restoration to plan an appropriate intervention of the altar frontal. Since in this artwork the role of mirrors is not to give back images, as usual, but rather to create special light effects and play of lights, this work aims to find an approach to the restoration of the altar frontal and its decorations that allows a homogeneous overview of the piece. Thus, the mirrors were not substituted or re-created. Only a visual integration of the damaged ancient mirrors was proposed, with the use of metallic-polymeric films, permitting a completely reversible restoration.     

The increasing role of non-State actors in education policy-making. Evidence from Uruguay

ABSTRACT

Over the last decades privatization policies have taken centre stage in many processes of educational reform globally. In Latin America, these policies have played an important role since the 1990s leading to an increasing participation of private agents in educational provision. The case of Uruguay stands out for having remained somehow apart from this privatization agenda. More recently, however, research has identified a significant shift in the discursive order especially driven by a series of new actors including think tanks and civil society organizations favourable to different forms of privatization. Building on case study methods and informed by a cultural political economy (CPE) approach this paper addresses two purposes. First, it attempts to explore possible explanations for the scarce development of the private sector in Uruguayan education. Second, it aims to characterize the discourses and strategies increasingly used by different actors to frame and promote policy ideas potentially leading to privatization policies. The study shows how a small but influential number of actors have become involved in the process of promoting ideas that seek to influence policymaking. Findings reveal how these actors frame school autonomy and accountability as policy solutions by means of different strategies of networking and knowledge mobilization.     

Enhanced neophobia induced by incentive contrast

In two experiments, a successive negative contrast effect in licking was produced by shifting rats from 32% to 4% sucrose solution. Subsequent to the downshift in reward, the rats were tested for licking either a plain 12% sucrose solution or 12% plus a neutral flavor. Licking for the 12% solution was depressed in downshifted rats when a flavor was present, regardless of whether this flavor was novel or had been present in the shift solution. The results were interpreted in terms of an enhancement of neophobia by reward reduction.     

The sociology of policy change within international organisations: beyond coercive and normative perspectives – towards circuits of power

ABSTRACT

For international organisations in the global education policy field, legitimacy is based in large part on the supposed techno-rational basis of these organisations and their ability to credibly produce knowledge and policy expertise. However, as the present article demonstrates, there are clearly a range of macro–micro organisational dynamics driving the production of knowledge and the policy ideas that are advanced. By revealing the way that a particular policy emerged and was promoted within the World Bank, this article seeks to expose the way that policy innovation is produced by the iterative interplay of agentic activity and particular organisational circumstances – and how this process is used to maintain and extend the influence of international organisations and the individuals who represent them. By drawing on Stewart Clegg’s ‘circuits of power’ approach, we seek to theorise the internal dynamics of international organisations, and, in so doing, to move beyond the dominant coercive and normative perspectives.     

Stability of memristor neural networks with delays operating in the flux-charge domain

The paper considers a class of neural networks where flux-controlled dynamic memristors are used in the neurons and finite concentrated delays are accounted for in the interconnections. Goal of the paper is to thoroughly analyze the nonlinear dynamics both in the flux-charge domain and in the current-voltage domain. In particular, a condition that is expressed in the form of a linear matrix inequality, and involves the interconnection matrix, the delayed interconnection matrix, and the memristor nonlinearity, is given ensuring that in the flux-charge domain the networks possess a unique globally exponentially stable equilibrium point. The same condition is shown to ensure exponential convergence of each trajectory toward an equilibrium point in the voltage-current domain. Moreover, when a steady state is reached, all voltages, currents and power in the networks vanish, while the memristors act as nonvolatile memories keeping the result of computation, i.e., the asymptotic values of fluxes. Differences with existing results on stability of other classes of delayed memristor neural networks, and potential advantages over traditional neural networks operating in the typical voltage-current domain, are discussed.     

‘That is like a 24 hours-day tournament!’: using social media to further an authentic sport experience within sport education

Several studies demonstrate that Sport Education supports the development of an authentic experience of sport. Social media has the potential to further the development of an authentic sport experience since it is a key aspect of contemporary sport culture and can be a space for individuals to interact during the Sport Education. Yet the evidence-base on the use of social media within Sport Education is limited. The purpose of this study was to explore how social media supports the development of an authentic sport experience within Sport Education. The context of this study was within a female recreational community sport futsal club. Players engaged with Sport Education as a focus for their sessions for 13 weeks. The Sport Education season embedded the six key features. During the Sport Education season, players interacted with each other through Facebook. Data were generated from; (1) researcher/player field journal, (2) Facebook posts and (3) post-season player interviews. Data analysis involved inductive, constant comparison and member-checking methods. Results showed that players’ uses of Facebook supported the development of an authentic sport experience. Players’ uses of Facebook strengthened the development of three key Sport Education features; affiliation, festivity and season. Based on the limited amount of research on the impact of social media within Sport Education and community sport, future studies should continue to examine the effectiveness of social media as an interactional tool to enhance the development of an authentic sport experience.