381 research outputs found
Prediction of the 3D surface topography after ball end milling and its influence on aerodynamics
The surface topography of milled workpieces often defines their performance. One example is blades in turbine engines, where the topography defines the flow losses. This type of complex goods is often machined by ball end mills, either for manufacture or repair. The literature offers various model types to predict the surface topography in order to design a machining process without prior experiment. The most accurate models use the real kinematics of the process and blend the tool with the workpiece. But this type of surface prediction ignores the differences between the reality and the simulation due to vibrations, tool chipping etc. This paper presents a combined approach using the kinematic topography from the machining simulation and adds a stochastic topography based on empirical data. It could be shown, that the usage of the stochastic topography greatly affects the flow losses and thus cannot be ignored.DFG/CRC/87
(un)Doing standards in education with actor-network theory
Recent critiques have drawn important attention to the depoliticized consensus and empty promises embedded in network discourses of educational policy. While acceding this critique, this discussion argues that some forms of network analysis â specifically those adopting actor-network theory (ANT) approaches - actually offer useful theoretical resources for policy studies. Drawing from ANT-inspired studies of policy processes associated with educational standards, the article shows the ambivalences and contradictions as well as the possibilities that can be illuminated by ANT analysis of standards as networks. The discussion outlines the diverse network conceptions, considerations and sensibilities afforded by ANT approaches. Then it shows four phenomena that have been highlighted by ANT studies of educational standards: ordering (and rupturing) practice through âimmutable mobilesâ, local universality, tensions among networks of prescription and networks of negotiation, and different co-existing ontological forms of the same standards. The conclusion suggests starting points, drawing from these ANT-inspired network analyses, for examining policy processes associated with educational standards
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Words, rules, and mechanisms of language acquisition
We review recent artificial language learning studies, especially those following Endress and Bonatti (2007), suggesting that humans can deploy a variety of learning mechanisms to acquire artificial languages. Several experiments provide evidence for multiple learning mechanisms that can be deployed in fluent speech: one mechanism encodes the positions of syllables within words and can be used to extract generalization, while the other registers co-occurrence statistics of syllables and can be used to break a continuum into its components. We review dissociations between these mechanisms and their potential role in language acquisition. We then turn to recent criticisms of the multiple mechanisms hypothesis and show that they are inconsistent with the available data. Our results suggest that artificial and natural language learning is best understood by dissecting the underlying specialized learning abilities, and that these data provide a rare opportunity to link important language phenomena to basic psychological mechanisms
Education and service : how theories can help in understanding tensions
Acknowledgements: our thanks to Ayelet Kuper for a helpfuldiscussion about the possible application of discourseanalysis to serviceâtraining tensionsPeer reviewedPostprin
Mapping children's presence in the neighbourhood
Within the work of Gert Biesta, public spaces are considered as the main fields where processes of civic learning can take place. Learning is always âin place and timeâ. Place matters, not only as a spatial background or set of conditions , but as a pedagogical process in itself. So in order to facilitate processes of civic learning we need to understand how spaces function as a co-educator in its own right.. In my PhD I studied how the neighbourhood can be understood as a co-educator. The processes through which children are socialised into a given order are not universal, nor neutral. One might state that children grow up into very different orders. The neighbourhood is an important factor into these diversified socialisation processes, but the neighbourhood is also made by its residents and users themselves, including children. This emphasises that socialisation is a relational process and not a functional oneway introduction of children into a prescribed social ordeIn this contribution, a methodological framework will be developed for understanding and studying the neighbourhood of children as a co-educator. The basis of this framework is formed by the synergy between spatial, social and personal dimensions of the neighbourhood
Investigating pupilsâ interactions around digital texts: a spatial perspective on the âclassroom-nessâ of digital literacy practices in schools
This paper complements debates around use of new technologies and literacy in education by proposing a focus on âclassroom-ness.â It highlights the significance of incidental, everyday and ephemeral practices associated with classroom technology-use. Using examples from a study of primary pupilsâ interactions around digital texts, it argues that we must acknowledge the distinctiveness of technology-use in classroom contexts but also see the spaces associated with those contexts as continually constructed, relational and heterogeneous. This helps us look beyond binary distinctions â between in/out of school and global/local practices, on/off-screen and on/offline activity, material/virtual contexts and official/unofficial discourses â to recognise the complex and nuanced ways that children make meaning around new technologies. It is proposed that this theoretical lens â in recognising the complexity of classroom-ness â can help us better understand the barriers and opportunities associated with effective integration of new technologies in educational contexts
Vocational knowledge in motion: rethinking vocational knowledge through vocational teachers' professional development
The paper presents empirical data to consider some of the current debates concerning the nature of vocational knowledge taught in Further Education colleges to students following craft, vocational and occupational courses. The concept of âknowledge in motionâ and workplace learning theories are employed as a conceptual framework to examine the continuing professional development (CPD) activities of vocational teachers. This is used to shed light on the ways in which teachers use CPD as a means of accessing and transporting vocational knowledge from occupations to classrooms. Empirical data were gathered through questionnaire, in-depth interviews and participant observation. The findings are presented around five themes: (1) the range of CPD engaged with by vocational teachers; (2) the limitations of propositional, explicit knowledge; (3) engaging with and capturing tacit knowledge; (4) managing the temporality of vocational knowledge; and (5) networking within and to the occupation. Findings suggests that vocational knowledge is distributed and networked and this conceptualisation makes visible some of the ways teachers are able, through CPD activity, to transport vocational knowledge from occupations to classrooms
The relationship between language production and verbal short-term memory: The role of stress grouping
This study investigates the influence of stress grouping on verbal short-term memory (STM). English speakers show a preference to combine syllables into trochaic groups, both lexically and in continuous speech. In two serial recall experiments, auditory lists of nonsense syllables were presented with either trochaic (STRONG-weak) or iambic (weak-STRONG) stress patterns, or in monotone. The acoustic correlates that carry stress were also manipulated in order to examine the relationship between input and output processes during recall. In Experiment 1, stressed and unstressed syllables differed in intensity and pitch but were matched for spoken duration. Significantly more syllables were recalled in the trochaic stress pattern condition than in the iambic and monotone conditions, which did not differ. In Experiment 2, spoken duration and pitch were manipulated but intensity was held constant. No effects of stress grouping were observed, suggesting that intensity is a critical acoustic factor for trochaic grouping. Acoustic analyses demonstrated that speech output was not identical to the auditory input, but that participants generated correct stress patterns by manipulating acoustic correlates in the same way in both experiments. These data challenge the idea of a language-independent STM store and support the notion of separable phonological input and output processes
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