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141.
A new approach to steady-state rolling, with and without force transmission, based on the boundary element method is presented. The proposed formulation solves the problem in a more general way than semi-analytical methods, with which it shares some approximations. The robustness and accuracy of the proposed method is reflected in the comparative analysis of the results obtained for three different types of rolling problems involving identical, dissimilar and tyred cylinders, respectively. 相似文献
142.
Rafael Gadea Gironés Rafael Gadea Gironés Ricardo Colom Palero Joaquín Cerdá Boluda Joaquín Cerdá Boluda Angel Sebastia Cortés 《The Journal of VLSI Signal Processing》2005,40(2):189-213
The paper describes the implementation of a systolic array for a multilayer perceptron with a hardware-friendly learning algorithm. A pipelined modification of the on-line backpropagation algorithm is shown and explained. It better exploits the parallelism because both the forward and backward phases can be performed simultaneously. The neural network performance for the proposed modification is discussed and compared with the standard so-called on-line backpropagation algorithm in typical databases and with the various precisions required. Although the preliminary results are positive, subsequent theoretical analysis and further experiments with different training sets will be necessary. For this reason our VLSI systolic architecture—together with the combination of FPGA reconfiguration properties and a design flow based on generic VHDL—can create a reusable, flexible, and fast method of designing a complete ANN on a single FPGA and can permit very fast hardware verifications for our trials of the Pipeline On-line Backpropagation algorithm and the standard algorithms. 相似文献
143.
A general model is proposed to optimize the shading interaction between an awning and an external wall that project shadows on the facade of a construction. The original method was presented by the authors in Renewable Energy 28 (2003): 111, for a particular shading proposal. They emphasize the advantage of a one-dimensional approach to solve the problem of this interaction, analyzing the shadows projected by these elements from a side view. The generalized method, presented in this paper, is useful for architects to design shelter projects with more alternatives in the use of such shading devices. The general model also permits study and evaluation of any strategy chosen by the builder to shadow a facade, with an emphasis on windowpane shading, through graphical outputs of the solar performance. 相似文献
144.
Natlia Moreno Xavier Querol Angel Lpez‐Soler Jos Manuel Andres Maria Janssen Henk Nugteren Mark Towler Kenneth Stanton 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(9):1009-1018
Zeolitic material is obtained from fly ash both by direct conversion of the ash or from SiO2 extracts obtained from fly ash. This study focuses on determining the suitability of a fly ash for SiO2 extraction and for zeolite synthesis by direct conversion. The SiO2 extraction experiments from different fly ashes show that the main parameters governing the SiO2 extraction are: (a) a high bulk SiO2 content (>52%, for obtaining an extraction yield of 100 g SiO2 kg?1) in the starting fly ash, (b) a high proportion (>55%) of the bulk SiO2 present in the degradable glass matrix and the highly soluble opaline fraction, and (c) a high bulk SiO2/Al2O3 ratio (>2.0) of the fly ash. The results from experiments of zeolite synthesis by direct conversion demonstrate that the most important criteria for the selection of a fly ash for this process are: (a) a high content of Al2O3 and SiO2(>65%) (b) a high glass content (>63%) and (c) relatively low SiO2/Al2O3 ratio (<2.0). Multivariate analysis confirms the importance of the above‐mentioned variables and shows some additional variables that have influence on ash behaviour under alkaline conditions. It quantifies the use of those variables for determining the suitability of ashes for SiO2 extraction and zeolite synthesis and is able to distinguish between the two. Copyright © 2004 Society of Chemical Industry 相似文献
145.
A Kumar JB Angel MP Daftarian K Parato WD Cameron L Filion F Diaz-Mitoma 《Canadian Metallurgical Quarterly》1998,114(1):78-86
The present study determines the proportions of unmyelinated cutaneous axons at the dermal-epidermal junction in glabrous skin and of myelinated and unmyelinated axons in the sural and medial plantar nerves that immunostain for subunits of the ionotropic glutamate receptors. Approximately 20% of the unmyelinated cutaneous axon profiles at the dermal-epidermal junction immunostain for either N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), or kainate receptor subunits. These findings are consistent with previous observations that NMDA and non-NMDA antagonists ameliorate nociceptive behaviors that result from noxious peripheral stimulation. In the sural nerve, where the large majority of myelinated fibers are sensory, approximately half of the myelinated axon profiles immunostain for the NMDA receptor 1 (R1) subunit, 28% immunostain for the glutamate receptor 1 (GluR1) AMPA subunit, and 11% for the GluR5,6,7 kainate subunits. Even higher proportions immunostain for these receptors in the medial plantar nerve, a mixed sensory and motor nerve. In the sural nerve, 20% of the unmyelinated axon profiles immunostain for NMDAR1 and only 7% label for GluR1 or GluR5,6,7. Because the sural nerve innervates hairy skin, these data suggest that glutamate will activate a higher proportion of unmyelinated axons in glabrous skin than in hairy skin. Measurements of fiber diameters indicate that all sizes of myelinated axon profiles, including Adelta and Abeta, are positively labeled for the ionotropic receptors. The presence of glutamate receptors on large-diameter myelinated axons suggests that these mechanosensitive receptors, presumably transducing touch and pressure, may also respond to local glutamate and thus be chemosensitive. 相似文献
146.
Rafael Alique Pilar Luna Teresa Hernández M. Angel Martínez 《European Food Research and Technology》2009,229(4):661-669
Atomised hot water vapour at between 46 and 54 °C for 60 min was tested as a method of delaying ripening and extending shelf
life in cv “Fino de Jete” cherimoya fruit (Annona cherimola Mill.). Heat treatment at 46 °C stimulated the respiration rate and starch degradation, induced ethylene production, increased
the accumulation of soluble sugars and α-amylase activity, and moved the onset of ethylene production (OEP) forward. Treatment
at 50 °C, and especially at 52 °C, delayed the climacteric peak and the OEP, decreased sugar and organic acid accumulation,
and reduced α-amylase and invertase activity. The results obtained indicate that temperatures higher than 48 °C slowed physiological
processes and carbohydrate metabolism and extend the shelf life of the cherimoya fruits, while temperatures higher than 52 °C
blocked ripening irreversibly. 相似文献
147.
James A. Anderson Fiona-Mairead McKenna Angel Linares-Solano Richard P. K. Wells 《Catalysis Letters》2007,119(1-2):16-20
By conducting the catalytic hydrogenation over water miscible Pd/carbon nanofibre catalysts, selective ring hydrogenation
of aromatic acids can be performed in aqueous solution without the need to provide protection for the external acid function. 相似文献
148.
Javier Garcia de Jalón Miguel Angel Serna Rafael Avilés 《Mechanism and Machine Theory》1981,16(5):557-566
In the first part of this study, a new method for solving the problem of kinematic analysis was presented, based on the concepts of “basic coordinates” and “link constraint equations”. In this second part, these same concepts are used to solve the problems of initial position, finite displacements and static equilibrium position of a mechanism with springs between its links. The proposed algorithms are elementary in their formulation and of exceptional efficiency in their performance. The methods describes are based on the solution of a problem of mathematical programming. Several examples are presented, giving an idea of the potential of said algorithms. 相似文献
149.
The precipitation of carbides in the Fe-C system aged at constant temperature is simulated considering two transformation
kernels of complex reactions, involving different impingement and rate-time factors. The metastable and stable phase are identified
by deconvolution of the experimental kinetics. The activation energy of carbides is found to depend, slightly, on the transformation
kernel in which it is used. 相似文献
150.