2,832 research outputs found

    A particle filter to reconstruct a free-surface flow from a depth camera

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    We investigate the combined use of a Kinect depth sensor and of a stochastic data assimilation method to recover free-surface flows. More specifically, we use a Weighted ensemble Kalman filter method to reconstruct the complete state of free-surface flows from a sequence of depth images only. This particle filter accounts for model and observations errors. This data assimilation scheme is enhanced with the use of two observations instead of one classically. We evaluate the developed approach on two numerical test cases: a collapse of a water column as a toy-example and a flow in an suddenly expanding flume as a more realistic flow. The robustness of the method to depth data errors and also to initial and inflow conditions is considered. We illustrate the interest of using two observations instead of one observation into the correction step, especially for unknown inflow boundary conditions. Then, the performance of the Kinect sensor to capture temporal sequences of depth observations is investigated. Finally, the efficiency of the algorithm is qualified for a wave in a real rectangular flat bottom tank. It is shown that for basic initial conditions, the particle filter rapidly and remarkably reconstructs velocity and height of the free surface flow based on noisy measurements of the elevation alone

    Acute kidney injury in critically ill cancer patients : an update

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    Patients with cancer represent a growing group among actual ICU admissions (up to 20 %). Due to their increased susceptibility to infectious and noninfectious complications related to the underlying cancer itself or its treatment, these patients frequently develop acute kidney injury (AKI). A wide variety of definitions for AKI are still used in the cancer literature, despite existing guidelines on definitions and staging of AKI. Alternative diagnostic investigations such as Cystatin C and urinary biomarkers are discussed briefly. This review summarizes the literature between 2010 and 2015 on epidemiology and prognosis of AKI in this population. Overall, the causes of AKI in the setting of malignancy are similar to those in other clinical settings, including preexisting chronic kidney disease. In addition, nephrotoxicity induced by the anticancer treatments including the more recently introduced targeted therapies is increasingly observed. However, data are sometimes difficult to interpret because they are often presented from the oncological rather than from the nephrological point of view. Because the development of the acute tumor lysis syndrome is one of the major causes of AKI in patients with a high tumor burden or a high cell turnover, the diagnosis, risk factors, and preventive measures of the syndrome will be discussed. Finally, we will briefly discuss renal replacement therapy modalities and the emergence of chronic kidney disease in the growing subgroup of critically ill post-AKI survivors

    Focus on ethics of admission and discharge policies and conflicts of interest

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    Factors influencing ICU referral at the end of life in the elderly

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    Referral to the intensive care unit (ICU) and frequency of do-not-resuscitate (DNR) decisions at the end of life (EOL) in adult hospitalized patients a parts per thousand yen75 years and those < 75 years were examined and influencing factors in the elderly were determined. Data were prospectively collected in all adult patients who deceased during a 12-week period in 2007 and a 16-week period in 2008 at a university hospital in Belgium. Overall, 330 adult patients died of whom 33% were a parts per thousand yen75 years old. Patients a parts per thousand yen75 years old were less often referred to ICU at the EOL (42% vs. 58%, p=0.008) and less frequently died in the ICU (31% vs. 46%, p=0.012) as compared to patients < 75 years old. However, there was no difference in frequency of DNR decisions (87% vs. 88%, p=0.937) for patients dying on non-ICU wards. After adjusting for age, gender, and the Charlson comorbidity index, being admitted on a geriatric ward (OR 0.30, 95% CI 0.10-0.85, p=0.024) and having an active malignant disease (OR 0.39, 95% CI 0.19-0.78, p=0.008) were the only factors associated with a lower risk of dying in the ICU. Patients a parts per thousand yen75 years are less often referred to the ICU at the EOL as compared to patients < 75 years old. However, the risk of dying in the ICU was only lower for elderly with cancer and for those admitted to the geriatric ward

    Global Optimization of H ∞ problems: Application to robust control synthesis under structural constraints

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    International audienceIn this paper, a new technique to compute a synthesis structured Robust Control Law is developed. This technique is based on global optimization methods using a Branch-and-Bound algorithm. The original problem is reformulated as a min/max problem with non-convex constraint. Our approach uses interval arithmetic to compute bounds and accelerate the convergence
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