Short-time quantum propagator and Bohmian trajectorie

We begin by giving correct expressions for the short-time action following the work Makri–Miller. We use these estimates to derive an accurate expression modulo Δt2 for the quantum propagator and we show that the quantum potential is negligible modulo Δt2 for a point source, thus justifying an unfortunately largely ignored observation of Holland made twenty years ago. We finally prove that this implies that the quantum motion is classical for very short times

COACHING BIOMECHANICS INTERFACE: SIMULATION MODELLING

Computer simulation modelling is a powerful tool that can be used to gain insight into the mechanics of gymnastics technique. Having identified the underlying mechanics performance may be optimised and new skills developed. As computer processing power has increased so have the applications for simulation modelling. Research is currently being conducted to combine simulation models with virtual reality environments to produce innovative gymnastics training aids

Propulsion and airframe aerodynamic interactions of supersonic V/STOL configurations, phase 1

A wind tunnel model of a supersonic V/STOL fighter configuration has been tested to measure the aerodynamic interaction effects which can result from geometrically close-coupled propulsion system/airframe components. The approach was to configure the model to present two different test techniques. One was a coventional test technique composed of two test modes. In the Flow-Through mode, absolute configuration aerodynamics are measured, including inlet/airframe interactions. In the Jet-Effects mode, incremental nozzle/airframe interactions are measured. The other test technique is a propulsion simulator approach, where a subscale, externally powered engine is mounted in the model. This allows proper measurement of inlet/airframe and nozzle/airframe interactions simultaneously

OPTIMISATION OF THE FELGE TO HANDSTAND ON PARALLEL BARS

The felge, or undersomersault, to handstand on parallel bars has become an important skill in Men’s Artistic Gymnastics as it forms the basis of many complex variations. To receive no deductions from the judges, the felge must be performed without demonstrating the use of strength to achieve the final handstand position. Two male gymnasts each performed nine trials of the felge from handstand to handstand while data were recorded using an automatic motion capture system. The highest and lowest scoring trials of each gymnast, as determined by four international judges, were chosen for further analysis. The technique used by each gymnast was optimised using a computer simulation model so that the final handstand position could be achieved with straight arms. Two separate optimisations found different techniques identified in the coaching literature that are used by gymnasts. Although the stoop stalder technique used by the two gymnasts was found to be more demanding than the clear circle technique in terms of the strength required, it offered the potential for more consistent performance and future developments in skill complexity

Quantum Blobs

Quantum blobs are the smallest phase space units of phase space compatible with the uncertainty principle of quantum mechanics and having the symplectic group as group of symmetries. Quantum blobs are in a bijective correspondence with the squeezed coherent states from standard quantum mechanics, of which they are a phase space picture. This allows us to propose a substitute for phase space in quantum mechanics. We study the relationship between quantum blobs with a certain class of level sets defined by Fermi for the purpose of representing geometrically quantum states.Comment: Prepublication. Dedicated to Basil Hile

Northern New Hampshire Youth in a Changing Rural Economy: A Ten-Year Perspective

The Coös Youth Study was a ten-year research project about growing up in a rural county undergoing transformative economic and demographic changes. The study addressed how these changes affected youths’ well-being as well as their plans to stay in the region, pursue opportunities elsewhere, permanently relocate, or return to their home communities with new skills and new ideas. In this report, the authors describe their findings and point to specific areas for action to support and retain North Country youth. The study was sponsored by the Neil and Louise Tillotson Fund of the New Hampshire Charitable Foundation as one component of the long-term research collaboration Tracking Change in the North Country

Multiple Instance Learning for Heterogeneous Images: Training a CNN for Histopathology

Multiple instance (MI) learning with a convolutional neural network enables end-to-end training in the presence of weak image-level labels. We propose a new method for aggregating predictions from smaller regions of the image into an image-level classification by using the quantile function. The quantile function provides a more complete description of the heterogeneity within each image, improving image-level classification. We also adapt image augmentation to the MI framework by randomly selecting cropped regions on which to apply MI aggregation during each epoch of training. This provides a mechanism to study the importance of MI learning. We validate our method on five different classification tasks for breast tumor histology and provide a visualization method for interpreting local image classifications that could lead to future insights into tumor heterogeneity