134 research outputs found

    Building Façade Separation in Vertical Aerial Images

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    Three-dimensional models of urban environments have great appeal and offer promises of interesting applications. While initially it was of interest to just have such 3D data, it increasingly becomes evident that one really would like to have interpreted urban objects. To be able to interpret buildings we have to split a visible whole building block into its different single buildings. Usually this is done using cadastral information to divide the single land parcels. The problem in this case is that sometimes the building boundaries derived from the cadastre are insufficiently accurate due to several reasons like old databases with lower accuracies or inaccuracies due to transformation between two coordinate systems. For this reason it can happen that a cadastral boundary coming from an old map is displaced by up to several meters and therefore divides two buildings incorrectly. To overcome such problems we incorporate the information from vertical aerial images. We introduce a façade separation method that is able to find individual building façades using multi view stereo. The purpose is to identify the individual façades and separate them from one another before on proceeds with the analysis of a façade’s details. The source was a set of overlapping, thus “redundant ” vertical aerial images taken by an UltraCam digital aerial camera. Therefore in a first step we determine the building block outlines using the building classification and use the height values from the Digital Surface Model (DSM) to determine approximate “façade quadrilaterals”. We also incorporate height discontinuities using the height profiles along the building outlines to enhance our façade separation. In a next step we detect repeated pattern in these “façade images ” and use them to separate the façades respectively building blocks from one another

    Eye-tracking during newborn intubations

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    Moisture adsorption and desorption behavior of raw materials for the t-rtm process

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    The use of fiber reinforced plastics (FRPs) has significant potential to reduce the weight of components. As regards the sustainability of these components, thermoplastic matrices offer more potential for recycling than thermoset ones. A possible manufacturing process for the production of thermoplastic FRPs is thermoplastic resin transfer molding (T-RTM). In this very moisture-sensitive process, ε-caprolactam in addition to an activator and catalyst polymerizes anionically to polyamide 6 (aPA6). The anionic polymerization of aPA6 is slowed down or even completely blocked by the presence of water. This study analyses the sorption behavior of the matrix, fiber, binder and core materials for the production of anionic polyamide 6 composites, which are processed in the thermoplastic RTM process. Water vapor sorption measurements are used to determine the adsorption and desorption behavior of the materials. The maximum moisture loading of the materials provides information about the water adsorption capacity of the material. This knowledge is crucial for correct handling of the materials to achieve a fast process and good properties of the final product

    Eye-tracking to observe compliance with hand hygiene in the intensive care unit – a randomised feasibility study

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    Background: Healthcare-associated infections are associated with increased patient mortality. Hand hygiene is the most effective method to reduce these infections. Despite simplification of this easy intervention, compliance with hand disinfection remains low. Current assessment of hand hygiene is mainly based on observation by hygiene specialists. The aim of this study was to investigate additional benefits of eye-tracking during the analysis of hand hygiene compliance of healthcare professionals in the intensive care unit. Methods: In a simulated, randomised cross-over study conducted at the interdisciplinary intensive care unit of the University Hospital Zurich (Switzerland), doctors and nurses underwent eye-tracking and completed two everyday tasks (injection of 10 micrograms of norepinephrine via a central venous line, blood removal from the central line) in two scenarios where alcoholic dispenser locations differed ("in-sight" and "out-of-sight"). The primary outcomes were dwell time, revisits, first fixation duration and average fixation time on three areas of interest (central venous line, alcohol dispenser, protective glove box) for both scenarios. Compliance with hand hygiene guidelines was analysed. Findings: 49 participants (35 nurses, 14 doctors) were included. Eye-tracking provided additional useful information compared to conventional observations. Dwell time, revisits, first fixation duration and average fixation time did not differ between the two scenarios for all areas of interest. Overall compliance with recommended hand hygiene measures was low in both doctors (mean 20%) and nurses (mean 42.9%). Conclusion: Compared to conventional observations offered additional helpful insights and provided an in-depth analysis of gaze patterns during the recording of hand hygiene compliance in the intensive care unit. Keywords: compliance; eye-tracking; hand hygiene; intensive care unit

    Reversible Barrier Switching of ZnO/RuO₂ Schottky Diodes

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    The current-voltage characteristics of ZnO/RuO₂ Schottky diodes prepared by magnetron sputtering are shown to exhibit a reversible hysteresis behavior, which corresponds to a variation of the Schottky barrier height between 0.9 and 1.3 eV upon voltage cycling. The changes in the barrier height are attributed to trapping and de-trapping of electrons in oxygen vacancies

    Polarization dependence of ZnO Schottky barriers revealed by photoelectron spectroscopy

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    In order to answer the question of whether Schottky barriers on polar ZnO surfaces are different at Zn- and O-terminated surfaces, the interface formation of n-type ZnO and different high work function metals and metal oxides (Pt, PtOₓ, and RuO₂) with Schottky barrier heights of up to 1.5 eV has been studied using photoelectron spectroscopy with in situ sample preparation. The experiments are designed to exclude the effects of substrate reduction and consequent Fermi level pinning by high concentrations of oxygen vacancies. Moreover, by including the Zn LMM Auger emission in the analysis, it is demonstrated that an accurate extraction of barrier heights needs to take into account that the screening of the photoelectron core hole can change in the course of contact formation. The polarization dependence of Schottky barriers, which is important for piezotronic applications, is in most cases dominated by the influence of defects. Reducing the influence of defects, up to ∼240 meV higher Schottky barriers are revealed on oxygen-terminated surfaces. This is opposite to what has been reported in the literature but agrees with the dependence of barrier heights expected for an incomplete screening of the polarization of ZnO by the electrode as for ferroelectric materials

    Variability and predictors of weekly pesticide exposure in applicators from organic, sustainable and conventional smallholder farms in Costa Rica

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    Estimates of pesticide exposure among applicators from low- and middle-income countries (LMICs) are scarce, and exposure assessment methods are sometimes costly or logistically unfeasible. We examined the variability in weeklong pesticide exposure among applicators in Costa Rica and its predictors.; We conducted a cross-sectional survey among 221 pesticide applicators from organic, sustainable and conventional farms in 2016. We administered structured questionnaires to assess pesticide application practices at two time points (4-6 weeks apart). We adapted an existing algorithm to fit the context of smallholders and derive weekly pesticide exposure scores. We used linear mixed-effect models to examine within-worker and between-worker score variability. We then identified sociodemographic and occupational predictors of weekly pesticide exposure scores.; We observed high within-worker and between-worker variability in weekly pesticide exposures (eg, up to 180-fold and 70-fold differences in average weekly exposures within and between workers, respectively; intraclass correlation coefficient=0.4). Applicators working on conventional and sustainable farms had exposure scores twofold and 1.5-fold higher than those working in organic farms, respectively. Farm workers who received training on pesticide use had weekly pesticide exposure scores of 33% (95% CI 1% to 55%) lower than those who did not receive any training.; In this study of applicators from smallholder farms in Costa Rica, we determined the importance of collecting questionnaire data on self-reported pesticide use repeatedly due to its high variability within workers and absence of application records. Our questionnaire-based exposure algorithm could allow the calculation of semiquantitative estimates of average pesticide exposure for applicators from other LMICs

    Coagulation side effects of enzymatic debridement in burned patients

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    Objectives Bromelain-based enzymatic debridement has emerged as a valuable option to the standard surgical intervention for debridement in burn injuries. Adverse effects on coagulation parameters after enzymatic debridement have been described. The purpose of this study was to compare the effect of enzymatic and surgical debridement on coagulation. Methods Between 03/2017 and 02/2021 patients with burn injuries with a total body surface area (TBSA) ≥ 1% were included in the study. Patients were categorized into two groups: the surgically debrided group and the enzymatically debrided group. Coagulation parameters were assessed daily for the first seven days of hospitalization. Results In total 132 patients with a mean TBSA of 17% were included in this study, of which 66 received enzymatic debridement and 66 received regular surgical-debridement. Patients receiving enzymatic debridement presented significantly higher factor-V concentration values over the first seven days after admission (p = 0.05). Conclusion Enzymatic debridement in burned patients does not appear to increase the risk of coagulation abnormalities compared with the regular surgical approach

    Where do ICU trainees really look? An eye-tracking analysis of gaze patterns during central venous catheter insertion

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    Background: There is limited knowledge about gaze patterns of intensive care unit (ICU) trainee doctors during the insertion of a central venous catheter (CVC). The primary objective of this study was to examine visual patterns exhibited by ICU trainee doctors during CVC insertion. Additionally, the study investigated whether differences in gaze patterns could be identified between more and less experienced trainee doctors. Methods: In a real-life, prospective observational study conducted at the interdisciplinary ICU at the University Hospital Zurich, Switzerland, ICU trainee doctors underwent eye-tracking during CVC insertion in a real ICU patient. Using mixed-effects model analyses, the primary outcomes were dwell time, first fixation duration, revisits, fixation count, and average fixation time on different areas of interest (AOI). Secondary outcomes were above eye-tracking outcome measures stratified according to experience level of participants. Results: Eighteen participants were included, of whom 10 were inexperienced and eight more experienced. Dwell time was highest for CVC preparation table ( p = 0.02), jugular vein on ultrasound image ( p < 0.001) and cervical puncture location ( p < 0.001). Concerning experience, dwell time and revisits on jugular vein on ultrasound image ( p = 0.02 and p = 0.04, respectively) and cervical puncture location ( p = 0.004 and p = 0.01, respectively) were decreased in more experienced ICU trainees. Conclusions: Various AOIs have distinct significance for ICU trainee doctors during CVC insertion. Experienced participants exhibited different gaze behavior, requiring less attention for preparation and handling tasks, emphasizing the importance of hand-eye coordination
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