A flexible approach to reassembling thin artifacts of unknown geometry

We present a novel 3D reassembly method for fragmented, thin objects with unknown geometry. Unlike past methods, we do not make any restrictive assumptions about the overall shape of the object, or its painted texture. Our key observation is that regardless of the object's shape, matching fragments will have similar geometry and photometry along and across their adjoining regions. We begin by encoding the scale variability of each fragment's boundary contour in a multichannel, 2D image representation. Using this multichannel boundary contour representation, we identify matching sub-contours via 2D partial image registration. We then align the fragments by minimizing the distance between their adjoining regions while simultaneously ensuring geometric continuity across them. The configuration of the fragments as they are incrementally matched and aligned form a graph structure that we use to improve subsequent matches. By detecting cycles in this graph, we identify subsets of fragments with interdependent alignments. We then minimize the error within the subsets to achieve a globally optimal alignment. We leverage user feedback to cull the otherwise exponential search space; after each new match is found and aligned, it is presented to a user for confirmation or rejection. Using ceramic pottery as the driving example, we demonstrate the accuracy and efficiency of our method on six real-world datasets.     

Suboptimal choice in nonhuman animals: Rats commit the sunk cost error

The present experiments investigated the sunk cost error, an apparently irrational tendency to persist with an initial investment, in rats. This issue is of interest because some have argued that nonhuman animals do not commit this error. Two or three fixed-ratio (FR) response requirements were arranged on one lever, and an escape option was arranged on a second lever. The FRs were of different sizes, and escaping was the behavior of interest. Several variables that might influence the decision to persist versus escape were manipulated: the number of trials with different FR schedules in an experimental session (Exps. 1 and 2), effort to escape (Exp. 2), and the size of the larger FR (Exp. 3). The sunk cost error would result in never escaping, and the optimal strategy would be to escape from the larger FR. The main variable that determined persisting versus escaping was the size of the large FR. Rats that escaped from the large FR-apparently optimal behavior-did so at a suboptimal point, and hence committed the sunk cost error.     

Lecturing in Post‐Compulsory Education: profession,occupation or reflective practice?

Abstract

This paper argues that a new conceptualisation of teaching in post‐compulsory education is required. Taking into account the radical ideology‐driven change experienced in the sector in recent times, it is suggested that there are difficulties with the model of the lecturer as a ‘professional’, chief amongst which is that lecturers do not seem to think of themselves in this way. It is suggested that any alternative conceptualisation must: (i) take into account lecturers' own conceptions of their working practices, (ii) reflect the range of these practices, and (Hi) reflect the epistemological and ethical basis of teaching, in particular lecturers' sense of the value and worth of what they do. Finally, some implications of the proposed model of teaching for management practice and development, and the potential of the approach for theory practice and practitioners, are explored.     

Towards a Practice of Critical Teaching about Teachers' Work

Abstract

This paper represents our struggle to interpret the practical intent of critical theory as a resource for teaching in a postgraduate degree in education. In this paper we argue for the increasing need for critical teaching about teacher's work at a time when the possibilities of engaging in a curriculum making practice capable of delivering on commitments to social justice seem less likely. We describe the struggle to develop a practice which opens up opportunities for our students (experienced teachers) to connect the life‐worlds of their classrooms with the relentlessly changing surrounding sociocultural milieu. On this nexus teachers have an opportunity to investigate the possibilities for developing agency as the makers of culture as opposed to the delivers of somebody else's curriculum