16,875 research outputs found

    Becoming a teacher educator : guidelines for induction : 2nd edition

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    The first edition of these guidelines was published in 2007. Since that date it has been used to support the induction of new teacher educators in the UK and beyond. The guidelines and the research which underpinned them also won the Sage BERA Practitioner Research Prize in 2009. But change in the higher education sector and in the field of teacher education mean that the time is now right for a second edition. This new edition has been revised in four main ways. Firstly, a considerable body of published international research focused on teacher educators has been produced since 2007 and the revised guidelines are informed by this work. Secondly, the new guidelines include the ‘voices’ of new teacher educators themselves gathered during our regular workshops for new teacher educators and our research projects. Thirdly, the revised edition aims to be more inclusive of all teacher educators, including those in further education. In terms of this latter group, it is informed by the limited literature available and our own research into the experiences of those teaching higher education programmes in further education colleges. Finally, the new guidelines seek to respond in a measured way to changing policy and contextual frameworks. These include the continued intensification and increasing fragmentation of academic work and identity in the higher education sector; and the wider questioning of the contribution of higher education to professional education for teachers

    Fracture simulation for zirconia toughened alumina microstructure

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    Purpose - The purpose of this paper is to describe finite element modelling for fracture and fatigue behaviour of zirconia toughened alumina microstructures. Design/methodology/approach - A two-dimensional finite element model is developed with an actual Al2O3Al{_2}O{_3} - 10 vol% ZrO2ZrO{_2} microstructure. A bilinear, time-independent cohesive zone law is implemented for describing fracture behaviour of grain boundaries. Simulation conditions are similar to those found at contact between a head and a cup of hip prosthesis. Residual stresses arisen from the mismatch of thermal coefficient between grains are determined. Then, effects of a micro-void and contact stress magnitude are investigated with models containing residual stresses. For the purpose of simulating fatigue behaviour, cyclic loadings are applied to the models. Findings - Results show that crack density is gradually increased with increasing magnitude of contact stress or number of fatigue cycles. It is also identified that a micro-void brings about the increase of crack density rate. Social implications - This paper is the first step for predicting the lifetime of ceramic implants. The social implications would appear in the next few years about health issues. Originality/value - This proposed finite element method allows describing fracture and fatigue behaviours of alumina-zirconia microstructures for hip prosthesis, provided that a microstructure image is available

    A bounded degree SOS hierarchy for polynomial optimization

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    We consider a new hierarchy of semidefinite relaxations for the general polynomial optimization problem (P): f∗=min⁡{ f(x):x∈K }(P):\:f^{\ast}=\min \{\,f(x):x\in K\,\} on a compact basic semi-algebraic set K⊂RnK\subset\R^n. This hierarchy combines some advantages of the standard LP-relaxations associated with Krivine's positivity certificate and some advantages of the standard SOS-hierarchy. In particular it has the following attractive features: (a) In contrast to the standard SOS-hierarchy, for each relaxation in the hierarchy, the size of the matrix associated with the semidefinite constraint is the same and fixed in advance by the user. (b) In contrast to the LP-hierarchy, finite convergence occurs at the first step of the hierarchy for an important class of convex problems. Finally (c) some important techniques related to the use of point evaluations for declaring a polynomial to be zero and to the use of rank-one matrices make an efficient implementation possible. Preliminary results on a sample of non convex problems are encouraging

    A DYNAMIC ANALYSIS OF THE EFFECTS OF A PRICE SUPPORT PROGRAM ON PRICE DYNAMICS AND PRICE VOLATILITY

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    This study presents an econometric analysis of the effects of a government price support program on price dynamics and price volatility. Price support programs, a common feature of agricultural policy, provide a lower-bound censoring of the distribution of market prices. An econometric model of market prices is developed using a dynamic Tobit specification under time-varying volatility. The model is applied to the U.S. non-fat dry milk market. It is used to investigate the impact of market liberalization on price dynamics and price volatility in the presence of private and public stocks. The econometric results show how the price support program and stocks (both private and public) affect expected price volatility.Agricultural and Food Policy,

    AN ECONOMETRIC ANALYSIS OF THE EFFECTS OF MARKET LIBERALIZATION ON PRICE DYNAMICS AND PRICE VOLATILITY

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    The paper investigates price dynamics under market liberalization, with a focus on the effects of lowering price floors. We analyze price dynamics by specifying and estimating a dynamic Tobit model under time-varying volatility, where the market price is censored by a government-set support price. The model is applied to the U.S. butter market over the last three decades. The econometric results show how the price support program affects both expected prices and the volatility of prices. It is found that the censoring effects of a price support program can be significant and large even if the price support is set relatively low.Demand and Price Analysis,

    SFNet: Learning Object-aware Semantic Correspondence

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    We address the problem of semantic correspondence, that is, establishing a dense flow field between images depicting different instances of the same object or scene category. We propose to use images annotated with binary foreground masks and subjected to synthetic geometric deformations to train a convolutional neural network (CNN) for this task. Using these masks as part of the supervisory signal offers a good compromise between semantic flow methods, where the amount of training data is limited by the cost of manually selecting point correspondences, and semantic alignment ones, where the regression of a single global geometric transformation between images may be sensitive to image-specific details such as background clutter. We propose a new CNN architecture, dubbed SFNet, which implements this idea. It leverages a new and differentiable version of the argmax function for end-to-end training, with a loss that combines mask and flow consistency with smoothness terms. Experimental results demonstrate the effectiveness of our approach, which significantly outperforms the state of the art on standard benchmarks.Comment: cvpr 2019 oral pape

    Towards a model of how designers mentally categorise design information

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    This study aims to explore how designers mentally categorise design information during the early sketching performed in the generative phase. An action research approach is particularly appropriate for identifying the various sorts of design information and the cognitive operations involved in this phase. Thus, we conducted a protocol study with eight product designers based on a descriptive model derived from cognitive psychological memory theories. Subsequent protocol analysis yielded a cognitive model depicting the mental categorisation of design information processing performed by designers. This cognitive model included a structure for design information (high, middle, and low levels) and linked cognitive operations (association and transformation). Finally, this paper concludes by discussing directions for future research on the development of new computational tools for designers

    Temporally coherent 4D reconstruction of complex dynamic scenes

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    This paper presents an approach for reconstruction of 4D temporally coherent models of complex dynamic scenes. No prior knowledge is required of scene structure or camera calibration allowing reconstruction from multiple moving cameras. Sparse-to-dense temporal correspondence is integrated with joint multi-view segmentation and reconstruction to obtain a complete 4D representation of static and dynamic objects. Temporal coherence is exploited to overcome visual ambiguities resulting in improved reconstruction of complex scenes. Robust joint segmentation and reconstruction of dynamic objects is achieved by introducing a geodesic star convexity constraint. Comparative evaluation is performed on a variety of unstructured indoor and outdoor dynamic scenes with hand-held cameras and multiple people. This demonstrates reconstruction of complete temporally coherent 4D scene models with improved nonrigid object segmentation and shape reconstruction.Comment: To appear in The IEEE Conference on Computer Vision and Pattern Recognition (CVPR) 2016 . Video available at: https://www.youtube.com/watch?v=bm_P13_-Ds
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