排序方式: 共有45条查询结果,搜索用时 731 毫秒
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Due to more and more restrictive emission standards, the air system of Diesel engines has evolved into a complex system with several coupled actuating and controlled variables. In this paper, a linear-quadratic regulator (LQR) is used as a model-based, multivariable, optimal control of the air system. This technique is validated by results of an on-board test. (© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Extending dynamic convex risk measures from discrete time to continuous time: A convergence approach
Mitja Stadje 《Insurance: Mathematics and Economics》2010,47(3):391-404
We present an approach for the transition from convex risk measures in a certain discrete time setting to their counterparts in continuous time. The aim of this paper is to show that a large class of convex risk measures in continuous time can be obtained as limits of discrete time-consistent convex risk measures. The discrete time risk measures are constructed from properly rescaled (‘tilted’) one-period convex risk measures, using a d-dimensional random walk converging to a Brownian motion. Under suitable conditions (covering many standard one-period risk measures) we obtain convergence of the discrete risk measures to the solution of a BSDE, defining a convex risk measure in continuous time, whose driver can then be viewed as the continuous time analogue of the discrete ‘driver’ characterizing the one-period risk. We derive the limiting drivers for the semi-deviation risk measure, Value at Risk, Average Value at Risk, and the Gini risk measure in closed form. 相似文献
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This paper presents an experimental and CFD numerical study of convective heat transfer in a rotating cascade. Infrared thermography
was used to measure surface temperature distribution on a rotating hollow blade, heated internally by secondary air. A CFD
numerical model was made according to the actual test rig geometry and operating conditions. Tests were carried out in an
iposonic flow regime at relatively low fluid temperatures, with the rotational and Reynolds numbers varied and hot-to-cool
air mass flow ratio kept constant. Experimental and numerical results for the blade pressure side are compared in terms of
surface temperature 2D distribution and Nusselt number one-dimensional distribution along the blade midspan, providing a reasonable
agreement. 相似文献
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An original gas chromatographic method has been developed for simultaneous determination of major terpenes and cannabinoids in plant samples and their extracts. The main issues to be addressed were the large differences in polarity and volatility between both groups of analytes, but also the need for an exhaustive decarboxylation of cannabinoid acidic forms. Sample preparation was minimised, also by avoiding any analyte derivatisation. Acetone was found to be the most appropriate extraction solvent. Successful chromatographic separation was achieved by using a medium polarity column. Limits of detection ranged from 120 to 260 ng/mL for terpenes and from 660 to 860 ng/mL for cannabinoids. Parallel testing proved the results for cannabinoids are comparable to those obtained from established HPLC methods. Despite very large differences in concentrations between both analyte groups, a linear range between 1 and 100 µg/mL for terpenes and between 10 and 1500 µg/mL for cannabinoids was determined. 相似文献