The generalised imbalanced forces of each node of the initial solution of the one-step algorithm for bus rollover collision are iterated to balance based on the improved gradient method. Meanwhile, the local perturbat...
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The generalised imbalanced forces of each node of the initial solution of the one-step algorithm for bus rollover collision are iterated to balance based on the improved gradient method. Meanwhile, the local perturbation method is introduced into the equilibrium iteration process of the generalised imbalanced forces of the nodes of the improved algorithm, and the final deformation of rollover collision is quickly obtained. Comparing with the original Newton-Raphson iteration method, the computational efficiency is greatly promoted, and the simulation precision of the one-step collision algorithm is guaranteed at the same time. A case study on rollover collision for a typical 12 meter bus body section is carried out using the improved one-step collision algorithm. The practical effectiveness of the proposed method of this paper is verified by comparing the simulation results with that of the original algorithm and rollover test.
Global Ozone Monitoring by Occultation of Stars (GOMOS) is a satellite instrument onboard the ENVISAT platform that was in operation during 2002-2012. During these years, GOMOS observed about 880 000 vertical profiles...
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ISBN:
(纸本)9780819497598
Global Ozone Monitoring by Occultation of Stars (GOMOS) is a satellite instrument onboard the ENVISAT platform that was in operation during 2002-2012. During these years, GOMOS observed about 880 000 vertical profiles of ozone, NO2, NO3 and aerosols. The GOMOS measurement principle is relatively simple based on the stellar-occultation technique. In this paper, we present an alternative retrieval algorithm for processing the GOMOS measurements. The presented algorithm is based on the so-called one-step approach, where both the spectral and the vertical inversions are executed simultaneously. This approach has several attractive features. In particular, the one-step approach allows a better use of the smoothness prior information and, unlike in the operative algorithm, the prior given to one specie affects the other species too. This feature is critical when going near the detection limit, especially in the upper troposphere lower stratosphere (UTLS) region. The main challenge in the GOMOS one-step algorithm is to find the correct smoothness priors for the different species at different altitudes. In this paper, we give a technical description of the one-step retrieval algorithm and discuss the differences between this and the operative algorithm. In the case study part of this paper, we compare the one-step and the operative ozone retrievals in Arctic region during the exceptional ozone-depletion conditions in spring 2011. We show that the quality of the ozone profiles can be improved by introducing the one-step algorithm. The improvement is drastic in the lower stratosphere at 15-20km altitude.
We present a one-step algorithm to solve the time-dependent Maxwell equations for systems with spatially varying permittivity and permeability. We compare the results of this algorithm with those obtained from the Yee...
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We present a one-step algorithm to solve the time-dependent Maxwell equations for systems with spatially varying permittivity and permeability. We compare the results of this algorithm with those obtained from the Yee algorithm and from unconditionally stable algorithms. We demonstrate that for a range of applications the one-step algorithm may be orders of magnitude more efficient than multiple time-step, finite-difference time-domain algorithms. We discuss both the virtues and limitations of this one-step approach.
A one-step algorithm for parallel negabinary addition of two negabinary numbers is achieved by minimizing the truth-table for the two-stepalgorithm. Without increasing the encoding cell size or adding complexity of t...
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A one-step algorithm for parallel negabinary addition of two negabinary numbers is achieved by minimizing the truth-table for the two-stepalgorithm. Without increasing the encoding cell size or adding complexity of the corresponding optical system, the proposed one-step scheme doubles the computation speed. The optical system can also be used to realize a one-step modified signed digit adder. Additionally, optical implementation of negabinary multiplication using this proposed one-step optical adder is discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.
In this letter, an algorithm is developed for the analysis of domains containing lossy media, in the time domain, using the onestep method that was proposed by De Raedt for lossless media. This method is known to be ...
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In this letter, an algorithm is developed for the analysis of domains containing lossy media, in the time domain, using the onestep method that was proposed by De Raedt for lossless media. This method is known to be unconditionally stable and so it can be interesting to use it for applications for which the Courant-Friedrich-Levy stability condition can be a limiting factor, e.g., for bioelectromagnetic applications. The perfectly matched layer absorbing conditions are also introduced in our algorithm.
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