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Other Calculation Methods (other + calculation_methods)

Distribution by Scientific Domains

Engineering	50%

Selected Abstracts

Fast analytical short-circuit current calculation of rectifier-fed auxiliary subsystems

EUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 3 2003
M. Kunz
The course of time of a three-phase rectifier system which its alternating valve participation can be interpreted as a continuous sequence of alternating switching states. To allow a more convenient calculation, the substitutional circuit with the converter is transformed into state-space coordinates. Hereby each operational mode of the rectifier can be represented by two linear independent space-phasor component networks. In the state-space, an analytical solution for this boundary value system can be carried out. After a retransformation back into the time domain, its time functions can be derived. In contrast to other calculation methods, no assumptions or simplifications have to be made like ideal smooth DC currents. Furthermore, all states of operation of the rectifier bridge can be easily calculated, which cover DC side idle-running to DC short-circuit. [source]

Linearization of second-order calibration curves in stable isotope dilution,mass spectrometry

FLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2001
Laurent B. Fay
Abstract The quantification of compounds using isotope dilution mass spectrometry requires the establishment of calibration curves prior to determination of any unknown sample. When calibration over a wide concentration range is required and/or when an overlap exists between internal standard and analyte ions (if mono- or di-isotopically-labelled internal standards are used), second-order calibration curves are obtained. In this paper we have compared several calculation methods to linearize such calibration curves. We found that the method published by Bush and Trager6 gives a satisfactory linear relationship between the corrected amount ratio y = Ql(Qu+tQl) (the value Qu being the amount of unlabelled analyte, Ql the amount of labelled internal standard and t, the fixed fraction of the internal standard, which is identical to the unlabelled analyte) and the ratio of unlabelled to labelled ion intensities. All the other calculation methods that have been published so far have failed to linearize the second-order calibration curve build-up over a wide concentration range. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Analysis of microwave components and circuits using the iterative method

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2004
A. Mami
Abstract This article presents an efficient implementation of an iterative method that includes a fast-mode transformation (FMT). The method has the advantages of simplicity and not involving basis functions and inversion of matrices, as used in other calculation methods. Therefore, this approach has the potential to be capable of analysing larger bodies than other classical techniques. An implementation of the iterative calculation is shown for the extraction of S parameters of microwave components and antennas. The good agreement between the simulation results and experimental published data justifies the design procedure and validates the present analysis approach. © 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14, 404,414, 2004. [source]

Analytical evaluation of the Voigt function using binomial coefficients and incomplete gamma functions

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2008
B. A. Mamedov
ABSTRACT Using the binomial expansion theorem, the simple general analytical expressions are obtained for the Voigt function arising in various fields of physical research. As we will seen, the present formulation yields compact closed-form expressions which enable the ready analytical calculation of the Voigt function. The validity of this approximation is tested by other calculation methods. The series expansion relations established in this work are accurate enough in the whole range of parameters. The convergence rate of the series is estimated and discussed. Some examples of this methodology are presented. [source]