1,518 research outputs found

    Variable anodic thermal control coating

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    A process for providing a thermal control solar stable surface coating for aluminum surfaces adapted to be exposed to solar radiation wherein selected values within the range of 0.10 to 0.72 thermal emittance (epsilon sub tau) and 0.2 to 0.4 solar absorptance (alpha subs) are reproducibly obtained by anodizing the surface area in a chromic acid solution for a selected period of time. The rate voltage and time, along with the parameters of initial epsilon sub tau and alpha subs, temperature of the chromic acid solution, acid concentration of the solution and the material anodized determines the final values of epsilon/tau sub and alpha sub S. 9 Claims, 5 Drawing Figures

    Appearance-based localization for mobile robots using digital zoom and visual compass

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    This paper describes a localization system for mobile robots moving in dynamic indoor environments, which uses probabilistic integration of visual appearance and odometry information. The approach is based on a novel image matching algorithm for appearance-based place recognition that integrates digital zooming, to extend the area of application, and a visual compass. Ambiguous information used for recognizing places is resolved with multiple hypothesis tracking and a selection procedure inspired by Markov localization. This enables the system to deal with perceptual aliasing or absence of reliable sensor data. It has been implemented on a robot operating in an office scenario and the robustness of the approach demonstrated experimentally

    Utility of patient decision aids (PDA) in stress urinary incontinence surgery

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    Introduction and hypothesis Patient decision aids (PDAs) facilitate shared decision making allowing patients to make decisions about their healthcare that take into account their personal values and preferences. The aim of this study was to establish whether a PDA used in women requiring stress incontinence surgery is helpful to women when making choices about the treatments they choose by using a Decision Conflict Scale (DCS). Methods Forty-five consecutive women were identified as having stress urinary incontinence and had completed all conservative treatments. All patients included in the study had stress urinary incontinence confirmed on urodynamic testing and were given the PDA at the point where they needed to make a decision about surgery. Following completion of the PDA, patients were given a DCS to complete which measures personal perceptions of uncertainty when making a decision about treatment. Results Forty-three out of 45 (95.5%) patients scored 4/4 for the DCS indicating they were sure of their decision. Two patients (4.5%) scored 3/4 and were therefore unsure of their choice. No patient scored < 3 on the DCS. The choice of procedures varied in all the ages and two women opted to have no treatment. Conclusions The use of a PDA in the surgical treatment of stress urinary incontinence reduces decision conflict and ensures patients are sure of their decision, understand the information provided as well as the risk benefit ratio of the various options and feel they have adequate support and advice to make a choice

    Learning globally consistent maps by relaxation

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    Mobile robots require the ability to build their own maps to operate in unknown environments. A fundamental problem is that odometry-based dead reckoning cannot be used to assign accurate global position information to a map because of drift errors caused by wheel slippage. The paper introduces a fast, online method of learning globally consistent maps, using only local metric information. The approach differs from previous work in that it is computationally cheap, easy to implement and is guaranteed to find a globally optimal solution. Experiments are presented in which large, complex environments were successfully mapped by a real robot, and quantitative performance measures are used to assess the quality of the maps obtained

    New species of Clavicornaltica Scherer (Coleoptera: Chrysomelidae) from continental Asia

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    Four new species of Clavicornaltica Scherer are described and illustrated, of which two are from China (C. dali new species and C. longsheng new species) and two are from Vietnam (C. tamdao new species and C. vietnamensis new species). The wing and metathorax are described and illustrated for the genus for the first time. A key to the newly described species is presented. Male genitalia of Clavicornaltica australis Konstantinov are illustrated for the first time

    Sharing Polarization within Quantum Subspaces

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    Given an ensemble of n spins, at least some of which are partially polarized, we investigate the sharing of this polarization within a subspace of k spins. We assume that the sharing results in a pseudopure state, characterized by a single purity parameter which we call the bias. As a concrete example we consider ensembles of spin-1/2 nuclei in liquid-state nuclear magnetic resonance (NMR) systems. The shared bias levels are compared with some current entanglement bounds to determine whether the reduced subspaces can give rise to entangled states.Comment: 7 pages, 3 figure

    3D modeling of indoor environments for a robotic security guard

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    Autonomous mobile robots will play a major role in future security and surveillance tasks for large scale environments such as shopping malls, airports, hospitals and museums. Robotic security guards will autonomously survey such environments, unless a remote human operator takes over control. In this context a 3D model can convey much more useful information than the typical 2D maps used in many robotic applications today, both for visualisation of information and as human machine interface for remote control. This paper addresses the challenge of building such a model of a large environment (50m x 60m) using data from the robot’s own sensors: a 2D laser scanner and a panoramic camera. The data are processed in a pipeline that comprises automatic, semi-automatic and manual stages. The user can interact with the reconstruction process where necessary to ensure robustness and completeness of the model. A hybrid representation, tailored to the application, has been chosen: floors and walls are represented efficiently by textured planes. Non-planar structures like stairs and tables, which are represented by point clouds, can be added if desired. Our methods to extract these structures include: simultaneous localization and mapping in 2D and wall extraction based on laser scanner range data, building textures from multiple omni-directional images using multi-resolution blending, and calculation of 3D geometry by a graph cut stereo technique. Various renderings illustrate the usability of the model for visualising the security guard’s position and environment

    A role for low concentration reaction intermediates in the signal amplification by reversible exchange process revealed by theory and experiment

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    A route to monitor the involvement of less abundant species during the catalytic transfer of hyperpolarisation from parahydrogen into a substrate is detailed. It involves probing how the degree of hyperpolarisation transfer catalysis is affected by the magnetic field experienced by the catalyst during this process as a function of temperature. The resulting data allows the ready differentiation of the roles played by hard to detect and highly reactive complexes, such as [Ir(H)2(NHC)(substrate)2(methanol)]Cl, from dominant species such as [Ir(H)2(NHC)(substrate)3]Cl. The difference in behaviour results from changes in the interligand spin-spin coupling network within the active SABRE catalysts

    Health economics

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    National BSUG audit of stress urinary incontinence surgery in England

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    Introduction and hypothesis The aim of the British Society of Urogynaecology (BSUG) 2013 audit for stress urinary incontinence (SUI) surgery was to conduct a national clinical audit looking at the intra- and postoperative complications and provide outcomes for these procedures. This audit was supported by the Healthcare Quality Improvement Partnership (HQIP) and National Health Service (NHS) England. Methods Data were collected for all continence procedures performed in 2013 through the BSUG database. All clinicians in England performing SUI surgery were invited to submit data to a central database. Outcomes data for the different continence procedures were collected and included intraoperative and postoperative complications and the change in continence scores at postoperative follow-up Changing trends in stress incontinence surgery were also assessed. Results We recorded 4993 urinary incontinence procedures from 177 consultants at 110 centres in England: 94.6% were midurethral slings; 86.7% (4331) were submitted by BSUG members with the remaining 13.3% submitted by non-BSUG members. Postoperative follow-up data were available for 3983 (80%) patients: 92.3% (3676) were very much better/much better postoperatively, and 4806 (96.3%) proceeded with no reported complications. There were 187 cases (3.7%) in which a perioperative complication was recorded. Pain persisting >30 days was reported in 1.9% of all patients. Conclusions Surgery for SUI has good outcomes in the short term. Midurethral synthetic slings have been shown to be safe and effective as a treatment option, with >90% being very much/much better at their postoperative follow-up
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