Vibration and Instability of Plate-Assemblies including Shear and Anisotropy (VIPASA) user's guide, addendum

Extensions developed at Langley Research Center to the VIPASA computer program are described including a procedure for simple thermal stress analysis and options for graphical display of output. Input requirements for operation of the modified program are given in detail

Self-tuned quantum dot gain in photonic crystal lasers

We demonstrate that very few (1 to 3) quantum dots as a gain medium are sufficient to realize a photonic crystal laser based on a high-quality nanocavity. Photon correlation measurements show a transition from a thermal to a coherent light state proving that lasing action occurs at ultra-low thresholds. Observation of lasing is unexpected since the cavity mode is in general not resonant with the discrete quantum dot states and emission at those frequencies is suppressed. In this situation, the quasi-continuous quantum dot states become crucial since they provide an energy-transfer channel into the lasing mode, effectively leading to a self-tuned resonance for the gain medium.Comment: 4 pages, 4 figures, submitted to Phys. Re

Inspiring to inspire: Developing teaching in higher education

Following a three-year staff development initiative within one faculty in a UK university, the authors reflected on inspiring teaching and the role that staff development can play in enhancing individual practice. Teaching is a core component of Higher Education and is complex and multi-faceted both theoretically and in practice. Through individual reflections to a set of pre-determined questions, a group of Higher Education teachers (n = 5) with a responsibility for the development of learning, teaching and assessment, share their thoughts, feelings and beliefs on inspiring teaching. The interpretive analysis of the data shows from a staff perspective that the notion of inspiring teaching has three main components which are all interrelated, those being; the actual teaching and learning experience; the design of the curriculum and the teacher/student relationship. Staff development initiatives were found to help people explore and develop their own teaching philosophy, to develop new practices and to share and learn from others. However, individual’s mindset, beliefs and attitudes were found to be a challenge. Teachers can frame their development around the different aspects of inspiring teaching and with support from senior leadership as well as a positive culture, teaching communities can work together towards inspiring teaching

Teacher–Student Dialogue During Classroom Teaching: Does It Really Impact on Student Outcomes?

It is now widely believed that classroom dialogue matters as regards student outcome, with optimal patterns often regarded as requiring some or all of: open questions; elaboration of previous contributions; reasoned discussion of competing viewpoints; linkage and coordination across contributions; meta-cognitive engagement with dialogue; high student participation. To date however, the relevance of such features has been most convincingly examined in relation to small-group interaction amongst students; little is known about applicability to teacher-student dialogue. The paper reports a large-scale study that permits some rebalancing. The study revolves around the two lessons (covering two of mathematics, literacy and science) that were video-recorded in each of 72 demographically diverse classrooms (students aged 10-11 years). Key measures of teacher-student dialogue were related to six indices of student outcome, which jointly covered curriculum mastery, reasoning, and educationally relevant attitudes. Prior attainment and attitudes were considered in analyses as were other factors, e.g. student demographics and further aspects of classroom practice, that might confound interpretation of dialogue-outcome relations. So long as students participated extensively, elaboration and querying of previous contributions were found to be positively associated with curriculum mastery, and elaboration was also positively associated with attitudes.ESR

Dialogic practices in primary school classrooms

Research into classroom dialogue suggests that certain forms are especially productive for students’ learning (Howe and Abedin, 2013). Despite the large number of studies in this area, there is inadequate evidence about the prevalence of the identified forms, let alone their productivity. However, scarcity is widely presumed. The overall aim of the study reported in this paper was to examine the extent to which the forms are embedded within current practice in UK primary schools. Video-recordings of two lessons from each of 36 classrooms formed the database, with two subjects from mathematics, English and science covered in each classroom. Each lesson was coded per turn for the presence of ‘dialogic moves’ and rated overall for the level of student involvement in specified activities. Results revealed that the supposedly productive forms were not always as scarce as sometimes presumed, while also highlighting huge variation in their relative occurrence. They also point to the role of professional development for teachers in promoting use of some forms

Towards hardware acceleration of neuroevolution for multimedia processing applications on mobile devices

This paper addresses the problem of accelerating large artificial neural networks (ANN), whose topology and weights can evolve via the use of a genetic algorithm. The proposed digital hardware architecture is capable of processing any evolved network topology, whilst at the same time providing a good trade off between throughput, area and power consumption. The latter is vital for a longer battery life on mobile devices. The architecture uses multiple parallel arithmetic units in each processing element (PE). Memory partitioning and data caching are used to minimise the effects of PE pipeline stalling. A first order minimax polynomial approximation scheme, tuned via a genetic algorithm, is used for the activation function generator. Efficient arithmetic circuitry, which leverages modified Booth recoding, column compressors and carry save adders, is adopted throughout the design

The Cut & Enhance method : selecting clusters of galaxies from the SDSS commissioning data

We describe an automated method, the Cut & Enhance method (CE) for detecting clusters of galaxies in multi-color optical imaging surveys. This method uses simple color cuts, combined with a density enhancement algorithm, to up-weight pairs of galaxies that are close in both angular separation and color. The method is semi-parametric since it uses minimal assumptions about cluster properties in order to minimize possible biases. No assumptions are made about the shape of clusters, their radial profile or their luminosity function. The method is successful in finding systems ranging from poor to rich clusters of galaxies, of both regular and irregular shape. We determine the selection function of the CE method via extensive Monte Carlo simulations which use both the real, observed background of galaxies and a randomized background of galaxies. We use position shuffled and color shuffled data to perform the false positive test. We have also visually checked all the clusters detected by the CE method. We apply the CE method to the 350 deg^2 of the SDSS (Sloan Digital Sky Survey) commissioning data and construct a SDSS CE galaxy cluster catalog with an estimated redshift and richness for each cluster. The CE method is compared with other cluster selection methods used on SDSS data such as the Matched Filter (Postman et al. 1996, Kim et al. 2001), maxBCG technique (Annis et al. 2001) and Voronoi Tessellation (Kim et al. 2001). The CE method can be adopted for cluster selection in any multi-color imaging surveys.Comment: 62 pages, 32 figures, Accepted for publication in the Astronomical Journal, "the CE galaxy cluster catalog can be downloaded from, http://astrophysics.phys.cmu.edu/~tomo/ce/

Cavity Quantum Electrodynamics with Anderson-localized Modes

A major challenge in quantum optics and quantum information technology is to enhance the interaction between single photons and single quantum emitters. Highly engineered optical cavities are generally implemented requiring nanoscale fabrication precision. We demonstrate a fundamentally different approach in which disorder is used as a resource rather than a nuisance. We generate strongly confined Anderson-localized cavity modes by deliberately adding disorder to photonic crystal waveguides. The emission rate of a semiconductor quantum dot embedded in the waveguide is enhanced by a factor of 15 on resonance with the Anderson-localized mode and 94 % of the emitted single-photons couple to the mode. Disordered photonic media thus provide an efficient platform for quantum electrodynamics offering an approach to inherently disorder-robust quantum information devices

Improving Global Knowledge Exchange for Mental Health Systems Improvement

Policymakers globally are paying increasing attention to the challenges of providing more accessible and integrated mental health care. For transformative change to take place, thought needs to be given to the structure and form of evidence-informed change strategies at all levels: individual, organizational, community and complex, large systems. Yet few frameworks specifically consider the transfer of evidence-based programs across jurisdictions at regional and national levels; most are focused on local service implementation. This paper examines how a specific analytical model developed to assess and develop Knowledge Exchange (KE) can be applied to regional and national KE initiatives.  It specifically examines the efforts of the International Knowledge Exchange Network for Mental Health (IKEN-MH), and the associated community of interest on change and improvement, to support mental health systems change at these levels. Using a theoretical model, the Promoting Action on Research Implementation in Health Services framework (Kitson, Harvey, & McCormack, 1998, Rycroft-Malone, et al., 2002), we explore systems change efforts according to the constructs of evidence, context and facilitation. By matching some exemplars in the use of KE for mental health best practice against this model, the potential strategies of the IKEN-MH to assist transformational change emerge