95 research outputs found

    Joint complete monotonicity of rational functions in two variables and toral mm-isometric pairs

    Full text link
    We discuss the problem of classifying polynomials p:R+2(0,)p : \mathbb R^2_+ \rightarrow (0, \infty) for which 1p={1p(m,n)}m,n0\frac{1}{p}=\{\frac{1}{p(m, n)}\}_{m, n \geq 0} is joint completely monotone, where pp is a linear polynomial in y.y. We show that if p(x,y)=a+bx+cy+dxyp(x, y)=a+b x+c y+d xy with a>0a > 0 and b,c,d0,b, c, d \geq 0, then 1p\frac{1}{p} is joint completely monotone if and only if adbc0.a d - b c \leq 0. We also present an application to the Cauchy dual subnormality problem for toral 33-isometric weighted 22-shifts.Comment: 28 page

    Design de fiabilidade bidimensional do software de múltiplos lançamentos tendo em conta o fator de redução de falhas na depuração imperfeita

    Get PDF
    Introduction: The present research was conducted at the University of Delhi, India in 2017. Methods: We develop a software reliability growth model to assess the reliability of software products released in multiple versions under limited availability of resources and time. The Fault Reduction Factor (frf) is considered to be constant in imperfect debugging environments while the rate of fault removal is given by Delayed S-Shaped model. Results: The proposed model has been validated on a real life four-release dataset by carrying out goodness of fit analysis. Laplace trend analysis was also conducted to judge the trend exhibited by data with respect to change in the system’s reliability. Conclusions: A number of comparison criteria have been calculated to evaluate the performance of the proposed model relative to only time-based multi-release Software Reliability Growth Model (srgm). Originality: In general, the number of faults removed is not the same as the number of failures experienced in given time intervals, so the inclusion of frf in the model makes it better and more realistic. A paradigm shift has been observed in software development from single release to multi release platform. Limitations: The proposed model can be used by software developers to take decisions regarding the release time for different versions, by either minimizing the development cost or maximizing the reliability and determining the warranty policies.Introducción: la presente investigación se realizó en la Universidad de Delhi, India en 2017. Métodos: desarrollamos un modelo de crecimiento de confiabilidad de software para evaluar la confiabilidad de los productos de software lanzados en múltiples versiones bajo disponibilidad limitada de recursos y tiempo. El factor de reducción de fallas (frf) se considera una constante en entornos de depuración imperfecta, mientras que la tasa de eliminación de fallas está dada por el modelo de forma retardada en S. Resultados: se valida el modelo propuesto en un conjunto de datos de cuatro lanzamientos de la vida real mediante un análisis de bondad de ajuste. También se aplicó el análisis de tendencia de Laplace para juzgar la tendencia que presentan los datos con respecto al cambio en la confiabilidad del sistema. Conclusiones: se calculó una serie de criterios de comparación para evaluar el rendimiento del modelo propuesto en relación con el modelo de crecimiento de confiabilidad del software (srgm) de múltiples lanzamientos basado únicamente en el tiempo. Originalidad: en general, el número de fallas eliminadas no es el mismo que el número de fallas experimentadas en intervalos de tiempo determinados, por lo que la inclusión de frf en el modelo lo mejora y lo hace más realista. Se ha observado un cambio de paradigma en el desarrollo de software, que pasa de un lanzamiento único a una plataforma múltiples lanzamientos. Limitaciones: los desarrolladores de software pueden emplear el modelo propuesto para tomar decisiones con respecto al tiempo de lanzar diferentes versiones, ya sea minimizando el costo de desarrollo o maximizando la confiabilidad y determinando las políticas de la garantía.Introdução: esta pesquisa foi realizada na Universidade de Deli, na Índia, em 2017. Métodos: desenvolvemos um modelo de crescimento de confiabilidade de software para avaliar a confiabilidade dos produtos de software lançados em múltiplas versões sob disponibilidade limitada de recursos e tempo. O fator de redução de falhas (frf) é considerado uma constante em contextos de depuração imperfeita, enquanto a taxa de eliminação de falhas é dada pelo modelo de forma retardada em S.Resultados: o modelo proposto é avaliado em um conjunto de dados de quatro lançamentos da vida real mediante uma análise de bondade de ajuste. Também foi utilizada a análise de tendência de Laplace para avaliar a tendência apresentada pelos dados com respeito à mudança na confiabilidade do sistema.Conclusões: uma série de critérios de comparação foi calculada para avaliar o rendimento do modelo proposto em relação com o modelo de crescimento de confiabilidade do software (srgm) de múltiplos lançamentos baseado unicamente no tempo.Originalidade: em geral, o número de falhas eliminadas não é o mesmo que o número de falhas existentes em intervalos de tempo determinados, sendo assim, a inclusão do frf no modelo o torna melhor e mais realista. Foi observada uma mudança de paradigma no desenvolvimento de software, que passa de um lançamento único a uma plataforma de múltiplos lançamentos.Limitações: o modelo proposto pode ser utilizado pelos desenvolvedores de software para tomar decisões com respeito ao tempo de lançar diferentes versões, seja para minimizar o custo de desenvolvimento ou maximizar a confiabilidade e determinar as políticas de garantia

    The Cauchy dual subnormality problem for cyclic 2-isometrie

    Get PDF
    The Cauchy dual subnormality problem asks whether the Cauchy dual operator of a 2-isometry is subnormal. Recently this problem has been solved in the negative. Here we show that it has a negative solution even in the class of cyclic 2-isometries

    Primitive neuroectodermal tumor with inferior vena cava thrombus: A rare case report

    Get PDF
    Primitive neuroectodermal tumors (PNETs) are rare type of small cell, aggressive tumors, commonly seen in the central nervoussystem, and PNET of the kidney with inferior vena cava thrombus is an extremely uncommon presentation of this entity. There are noestablished distinctive signs or radiological characteristics for diagnosis, but a majority of cases report positivity for CD99 marker.The patients usually present in the advanced stages of the disease and require progressive techniques of immunohistochemicalanalysis and expertise of multidisciplinary team of physicians to arrive at a correct diagnosis and have a proper management.Although rare, these tumors should be considered in the differential diagnosis of all patients with large renal masses, especially inthe younger population. We present a case of a 23-years-old female, with PNET of the left kidney, treated with radical nephrectomyand adjuvant chemotherapy

    Blink and it's done: Interactive queries on very large data

    Get PDF
    In this demonstration, we present BlinkDB, a massively parallel, sampling-based approximate query processing framework for running interactive queries on large volumes of data. The key observation in BlinkDB is that one can make reasonable decisions in the absence of perfect answers. BlinkDB extends the Hive/HDFS stack and can handle the same set of SPJA (selection, projection, join and aggregate) queries as supported by these systems. BlinkDB provides real-time answers along with statistical error guarantees, and can scale to petabytes of data and thousands of machines in a fault-tolerant manner. Our experiments using the TPC-H benchmark and on an anonymized real-world video content distribution workload from Conviva Inc. show that BlinkDB can execute a wide range of queries up to 150x faster than Hive on MapReduce and 10--150x faster than Shark (Hive on Spark) over tens of terabytes of data stored across 100 machines, all with an error of 2--10%.National Science Foundation (U.S.) (CISE Expeditions Award CCF-1139158)QUALCOMM Inc.Amazon.com (Firm)Google (Firm)SAP CorporationBlue GojiCisco Systems, Inc.Cloudera, Inc.Ericsson, Inc.General Electric CompanyHewlett-Packard CompanyIntel CorporationMarkLogic CorporationMicrosoft CorporationNetAppOracle CorporationSplunk Inc.VMware, Inc.United States. Defense Advanced Research Projects Agency (Contract FA8650-11-C-7136

    An open-label, multicenter, randomized, parallel, single-dose, comparative bioavailability study of two triamcinolone hexacetonide injectable suspensions in patients with knee osteoarthritis

    Get PDF
    Background: Triamcinolone hexacetonide (THA), a synthetic glucocorticoid with low solubility, can provide sustained pain relief and less systemic side effects in patients with knee osteoarthritis. This study aimed to characterize pharmacokinetic profile of THA-test product containing 20 mg/ml injectable suspension and compare its bioavailability with the standard reference in Indian patients with knee osteoarthritis. Methods: In this open-label, randomized, multicenter study, 44 adult patients were randomized (1:1; test n=23, reference n=21) to receive a single dose of test or reference products. The primary objective was to characterize the pharmacokinetic profile and compare bioavailability of both products via serum triamcinolone acetonide (TCA) concentration. Secondary objectives included safety and tolerability evaluation, impact on hypothalamic-pituitary-adrenal axis, and efficacy of test and reference products in reducing index knee pain. Results: Both products were absorbed with a median Tmax of 23.9 hours. Comparative bioavailability analysis demonstrated no statistically significant formulation effect for ln-transformed Cmax (1098.052 pg/ml for test, 1333.850 pg/ml for reference) and AUC0-t (159112.561 pg×h/ml for test, 211531.035 pg×h/ml for reference) for TCA. T/R ratio for Cmax was 82.3% and T/R ratio for AUC0-t was 75.2%, with >100% inter-subject variability for both Cmax and AUC0-t. Additionally, recovery time of cortisol levels of test and reference arms was 96 hours and 456 hours, respectively. Both products significantly reduced knee pain (p<0.0001). Conclusions: The test product provided lower systemic exposure and faster recovery of serum cortisol levels than the reference, while still providing similar beneficial effect in sustained index knee pain reduction
    corecore