1,102 research outputs found

    A dimensionally split Cartesian cut cell method for the compressible Navier–Stokes equations

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    We present a dimensionally split method for computing solutions to the compressible Navier-Stokes equations on Cartesian cut cell meshes. The method is globally second order accurate in the L1 norm, fully conservative, and allows the use of time steps determined by the regular grid spacing. We provide a description of the three-dimensional implementation of the method and evaluate its numerical performance by computing solutions to a number of test problems ranging from the nearly incompressible to the highly compressible flow regimes. All the computed results show good agreement with reference results from theory, experiment and previous numerical studies. To the best of our knowledge, this is the first presentation of a dimensionally split cut cell method for the compressible Navier-Stokes equations in the literature

    Trustworthy Quantum Computation through Quantum Physical Unclonable Functions

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    Quantum computing is under rapid development, and today there are several cloud-based, quantum computers (QCs) of modest size (>100s of physical qubits). Although these QCs, along with their highly-specialized classical support infrastructure, are in limited supply, they are readily available for remote access and programming. This work shows the viability of using intrinsic quantum hardware properties for fingerprinting cloud-based QCs that exist today. We demonstrate the reliability of intrinsic fingerprinting with real QC characterization data, as well as simulated QC data, and we detail a quantum physically unclonable function (Q-PUF) scheme for secure key generation using unique fingerprint data combined with fuzzy extraction. We use fixed-frequency transmon qubits for prototyping our methods

    Correction for Stokes' Law

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    The Provision of Time to the Elderly by Their Children

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    This paper uses matched data on the elderly and their children to study the provision of time by children to the elderly. It develops a Tobit model as well as a structural model to analyze the determinants of this decision. The main determinants of the amount of time given to parents appear to be the parent's age, reported health, and institutionalization status, and the children's age, health, and sex. Older parents, less healthy parents, and non-institutionalized parents receive more time from their children, while younger children, healthier children, and female children provide more time. In contrast to these demographic determinants, economic variables, such as children's wage rate and income levels, appear to play a rather insignificant role in the provision of time. In addition, the evidence does not support the hypothesis that parents purchase time from their children.

    The annuitization of Americans' resources: a cohort analysis

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    An analysis of the changes since 1960 in the share of Americans' resources that are annuitized, which has declined slightly for younger Americans but has risen dramatically for the elderly, with important implications for the national saving rate and income inequality.Saving and investment

    Uterine artery embolization: the only life saving measure in some obstetric cases

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    Uterine artery embolization is a highly specialised and efficacious method that can be used prophylactically to reduce obstetric haemorrhage. Its use in modern obstetrics is currently limited to morbidly adherent placenta and acreta. This report presents a case where uterine artery embolization has been used as the primary treatment for obstetric haemorrhage in a patient with high risk for PPH where surgical management would not have been possible. We aim at highlighting the benefits of this procedure in terms of reduced surgical blood loss, morbidity and fertility preservation

    Pyrexia of unknown origin: a rare presentation of primary ovarian lymphoma

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    It is very rare to have a lymphomatous involvement of ovary. Malignant lymphoma of ovary is a well-known late manifestation of disseminated nodal disease. Primary ovarian lymphoma with ovarian mass as an initial manifestation is a rare entity and may have varied presentations which can cause confusion to the physician and cause delay in diagnosis. Study presents a case of non-Hodgkin’s lymphoma where the initial presentation was fever with weight loss, and was evaluated as pyrexia of unknown origin. When no other cause of fever was identified PET-CT was done showing metabolically active uterine mass with no lymphadenopathy. Exploratory laparotomy was planned followed by hysterectomy with bilateral salpingo ophorectomy with omentectomy. Ovarian malignancy was detected intraoperatively, which was diagnosed as diffuse large B cell lymphoma, NHL double expresser phenotype on histopathology and IHC. Patient was started on chemotherapy and is doing fine
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