279 research outputs found

    Human from Blur: Human Pose Tracking from Blurry Images

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    We propose a method to estimate 3D human poses from substantially blurred images. The key idea is to tackle the inverse problem of image deblurring by modeling the forward problem with a 3D human model, a texture map, and a sequence of poses to describe human motion. The blurring process is then modeled by a temporal image aggregation step. Using a differentiable renderer, we can solve the inverse problem by backpropagating the pixel-wise reprojection error to recover the best human motion representation that explains a single or multiple input images. Since the image reconstruction loss alone is insufficient, we present additional regularization terms. To the best of our knowledge, we present the first method to tackle this problem. Our method consistently outperforms other methods on significantly blurry inputs since they lack one or multiple key functionalities that our method unifies, i.e. image deblurring with sub-frame accuracy and explicit 3D modeling of non-rigid human motion.Comment: typos and minor error fixe

    Discretization of variational regularization in Banach spaces

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    Consider a nonlinear ill-posed operator equation F(u)=yF(u)=y where FF is defined on a Banach space XX. In general, for solving this equation numerically, a finite dimensional approximation of XX and an approximation of FF are required. Moreover, in general the given data \yd of yy are noisy. In this paper we analyze finite dimensional variational regularization, which takes into account operator approximations and noisy data: We show (semi-)convergence of the regularized solution of the finite dimensional problems and establish convergence rates in terms of Bregman distances under appropriate sourcewise representation of a solution of the equation. The more involved case of regularization in nonseparable Banach spaces is discussed in detail. In particular we consider the space of finite total variation functions, the space of functions of finite bounded deformation, and the LL^\infty--space

    Methodological reflections on using pilot data from fracture patients to develop a qualitative study

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    Background: Qualitative studies are particularly valued for their exploratory nature but, like other research methods, they do require careful planning to ensure rigorous study design. Our objective was to undertake a pilot study to inform the development of a larger qualitative study. Results: We conducted a series of brief interviews with out-patients in a hospital setting. The interviews were designed to elicit superficial information about whether (and how) post-fracture osteoporosis investigation and/or treatment were being initiated among patients receiving treatment or follow-up for a current or recent fracture. We used thematic analysis to identify key themes in the data that related to the broader research questions. We analysed data obtained from 11 out of a total of 12 interviews conducted. Participants were male and female, aged 19-83 years of age (median age 57 years). Participants attended 2-8 medical appointments to seek treatment and follow up for a current or recent fracture. The following four overarching themes emerged from thematic analysis of the data: fracture event, referral pathway, osteoporosis investigation and/or treatment, and communication by health practitioners and staff. Conclusions: This pilot study was necessarily tentative and exploratory in nature, but provided a helpful snapshot of some typical experiences in the public health system following fracture. Several themes emerged for consideration in the design of the main study. Despite its critics, theoretical sampling and saturation continue to provide sustainable methods for ensuring that relevant themes and categories are covered in sufficient depth and breadth, appropriate to the needs of the study

    A Spectroscopic Study of Mass Outflows in the Interacting Binary RY Scuti

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    The massive interacting binary RY Scuti is an important representative of an active mass-transferring system that is changing before our eyes and which may be an example of the formation of a Wolf-Rayet star through tidal stripping. Utilizing new and previously published spectra, we present examples of how a number of illustrative absorption and emission features vary during the binary orbit. We identify spectral features associated with each component, calculate a new, double-lined spectroscopic binary orbit, and find masses of 7.1 +/- 1.2 M_sun for the bright supergiant and 30.0 +/- 2.1 M_sun for the hidden massive companion. Through tomographic reconstruction of the component spectra from the composite spectra, we confirm the O9.7 Ibpe spectral class of the bright supergiant and discover a B0.5 I spectrum associated with the hidden massive companion; however, we suggest that the latter is actually the spectrum of the photosphere of the accretion torus immediately surrounding the massive companion. We describe the complex nature of the mass loss flows from the system in the context of recent hydrodynamical models for beta Lyr, leading us to conclude RY Scuti has matter leaving the system in two ways: 1) a bipolar outflow from winds generated by the hidden massive companion, and 2) mass from the bright O9.7 Ibpe supergiant flowing from the region near the L2 point to fill out a large, dense circumbinary disk. This circumbinary disk (radius ~ 1 AU) may feed the surrounding double-toroidal nebula (radius ~ 2000 AU).Comment: 41 pages with 7 tables and 11 figures, accepted to Ap

    Methodological reflections on using pilot data from fracture patients to develop a qualitative study

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    Background: Qualitative studies are particularly valued for their exploratory nature but, like other research methods, they do require careful planning to ensure rigorous study design. Our objective was to undertake a pilot study to inform the development of a larger qualitative study.Results: We conducted a series of brief interviews with out-patients in a hospital setting. The interviews were designed to elicit superficial information about whether (and how) post-fracture osteoporosis investigation and/or treatment were being initiated among patients receiving treatment or follow-up for a current or recent fracture. We used thematic analysis to identify key themes in the data that related to the broader research questions. We analysed data obtained from 11 out of a total of 12 interviews conducted. Participants were male and female, aged 19-83 years of age (median age 57 years). Participants attended 2-8 medical appointments to seek treatment and follow up for a current or recent fracture. The following four overarching themes emerged from thematic analysis of the data: fracture event, referral pathway, osteoporosis investigation and/or treatment, and communication by health practitioners and staff.Conclusions: This pilot study was necessarily tentative and exploratory in nature, but provided a helpful snapshot of some typical experiences in the public health system following fracture. Several themes emerged for consideration in the design of the main study. Despite its critics, theoretical sampling and saturation continue to provide sustainable methods for ensuring that relevant themes and categories are covered in sufficient depth and breadth, appropriate to the needs of the study.<br /

    Observations of Particulates within the North Atlantic Flight Corridor: POLINAT 2, September-October 1997

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    This paper discusses particulate concentration and size distribution data gathered using the University of Missouri-Rolla Mobile Aerosol Sampling System (UMR-MASS), and used to investigate the southern extent of the eastern end of the North Atlantic Flight Corridor (NAFC) during project Pollution From Aircraft Emissions in the North Atlantic Flight Corridor/Subsonic Assessment (SASS) Ozone and Nitrogen Oxide Experiment (POLINAT 2/SONEX) from September 19 to October 23, 1997. The analysis presented in this paper focuses on the corridor effect, or enhancement of pollutants by jet aircraft combustion events. To investigate the phenomena, both vertical and horizontal profiles of the corridor, and regions immediately adjacent to the corridor, were performed. The profiles showed a time-dependent enhancement of particulates within the corridor, and a nonvolatile (with respect to thermal volatilization at 300° C) aerosol enhancement at corridor altitudes by a factor of 3.6. The southern extent of the North Atlantic Flight Corridor was established from a four flight average of the particulate data and yielded a boundary near 42.5° N during the study period. A size distribution analysis of the nonvolatile particulates revealed an enhancement in the \u3c40 nm particulates for size distributions recorded within the flight corridor

    An inter-laboratory effort to harmonize the cell-delivered in vitro dose of aerosolized materials

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    Air-liquid interface (ALI) lung cell models cultured on permeable transwell inserts are increasingly used for respiratory hazard assessment requiring controlled aerosolization and deposition of any material on ALI cells. The approach presented herein aimed to assess the transwell insert-delivered dose of aerosolized materials using the VITROCELL® Cloud12 system, a commercially available aerosol-cell exposure system. An inter-laboratory comparison study was conducted with seven European partners having different levels of experience with the VITROCELL® Cloud12. A standard operating procedure (SOP) was developed and applied by all partners for aerosolized delivery of materials, i.e., a water-soluble molecular substance (fluorescence-spiked salt) and two poorly soluble particles, crystalline silica quartz (DQ12) and titanium dioxide nanoparticles (TiO2 NM-105). The material dose delivered to transwell inserts was quantified with spectrofluorometry (fluorescein) and with the quartz crystal microbalance (QCM) integrated in the VITROCELL® Cloud12 system. The shape and agglomeration state of the deposited particles were confirmed with transmission electron microscopy (TEM). Inter-laboratory comparison of the device-specific performance was conducted in two steps, first for molecular substances (fluorescein-spiked salt), and then for particles. Device- and/or handling-specific differences in aerosol deposition of VITROCELL® Cloud12 systems were characterized in terms of the so-called deposition factor (DF), which allows for prediction of the transwell insert-deposited particle dose from the particle concentration in the aerosolized suspension. Albeit DF varied between the different labs from 0.39 to 0.87 (mean (coefficient of variation (CV)): 0.64 (28%)), the QCM of each VITROCELL® Cloud 12 system accurately measured the respective transwell insert-deposited dose. Aerosolized delivery of DQ12 and TiO2 NM-105 particles showed good linearity (R2 > 0.95) between particle concentration of the aerosolized suspension and QCM-determined insert-delivered particle dose. The VITROCELL® Cloud 12 performance for DQ12 particles was identical to that for fluorescein-spiked salt, i.e., the ratio of measured and salt-predicted dose was 1.0 (29%). On the other hand, a ca. 2-fold reduced dose was observed for TiO2 NM-105 (0.54 (41%)), which was likely due to partial retention of TiO2 NM-105 agglomerates in the vibrating mesh nebulizer of the VITROCELL® Cloud12. This inter-laboratory comparison demonstrates that the QCM integrated in the VITROCELL® Cloud 12 is a reliable tool for dosimetry, which accounts for potential variations of the transwell insert-delivered dose due to device-, handling- and/or material-specific effects. With the detailed protocol presented herein, all seven partner laboratories were able to demonstrate dose-controlled aerosolization of material suspensions using the VITROCELL® Cloud12 exposure system at dose levels relevant for observing in vitro hazard responses. This is an important step towards regulatory approved implementation of ALI lung cell cultures for in vitro hazard assessment of aerosolized materials
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