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Alexei Manso Corrêa Machado 《Journal of Mathematical Imaging and Vision》2007,29(2-3):107-117
We present a novel method for correcting the significance level of hypothesis testing that requires multiple comparisons. It is based on the spectral graph theory, in which the variables are seen as the vertices of a complete undirected graph and the correlation matrix as the adjacency matrix that weights its edges. The method increases the statistical power of the analysis by refuting the assumption of independence among variables, while keeping the probability of false positives low. By computing the eigenvalues of the correlation matrix, it is possible to obtain valuable information about the dependence levels among the variables of the problem, so that the effective number of independent variables can be estimated. The method is compared to other available models and its effectiveness illustrated in case studies involving high-dimensional sets of variables. 相似文献
45.
S. V. Prikhodko Y. Ma A. J. Ardell D. G. Isaak J. D. Carnes S. Moser 《Metallurgical and Materials Transactions A》2003,34(9):1863-1868
The adiabatic elastic stiffness constants C
ij of Ni-Si single-crystal solid-solution alloys of two slightly different compositions, 10.78 and 11.17 at. pct Si, were measured
over the temperature range from 20 °C to 900 °C using the rectangular parallelepiped resonance method. The isotropic elastic
constants of the polycrystalline ordered intermetallic compound Ni3Si containing 23 at. pct Si were also measured over this temperature range. Values of the C
ij for Ni3Si were estimated from the data on the polycrystalline alloy, as well as from published data in the literature on isomorphous
ternary ordered intermetallic compounds containing different amounts of Si. Using measured values and previously published
data, the stiffness constants of Ni3Ti were estimated; these are the only available data on this alloy. The estimated single-crystal elastic constants of Ni3Si, as well as the experimentally measured bulk modulus, are considerably smaller than published values calculated from first-principles
methods. The same is true for the C
ij of Ni3Ti, but the discrepancies are smaller. 相似文献
46.
煤基链篦机-回转窑一步法直接还原设备改造及技术操作要点 总被引:2,自引:0,他引:2
本文主要论述了煤基链篦机-回转窑一步法直接还原关键设备改造及有关技术操作要点,并提出了进一步提高产量,稳定操作,延长作业周期,降低生产成本的技术改造方案。 相似文献
47.
针对TPS/TDC30 0 0系统串口通讯方式、机理进行了一般性的介绍 ,对规划与应用中常见的的问题 ,根据实际工程应用经验提出了解决方案。 相似文献
48.
Francisco Jos Alguacil Concepcin Caravaca María Isabel Martín 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2003,78(10):1048-1053
The transport of chromium(VI) through a flat‐sheet supported liquid membrane containing Cyanex 921 as a carrier has been investigated. The permeation of the metal is investigated as a function of various experimental variables: hydrodynamic conditions, concentration of chromium(VI) and HCl in the feed phase, carrier concentration and diluent in the membrane and strippant concentration in the stripping phase. The mass transfer coefficient and the thickness of the aqueous boundary layer were calculated from the experimental data. Furthermore, the selectivity of Cyanex 921‐based flat‐sheet supported liquid membrane towards different metal ions and the behaviour of the system against other carriers are presented. Copyright © 2003 Society of Chemical Industry 相似文献
49.
AK Ma?ek O Rowiński T Ostrowski L Hilgertner M Januszewicz M Szostek 《Canadian Metallurgical Quarterly》1995,50(40-44):19-22
Subclavian steal syndrome (SSS) appears when the origin of the subclavian artery (SA) is occluded or stenosed. Introduction of transcranial Doppler sonography (TCD) provided an opportunity to evaluate parameters of the blood flow in the vertebral (VA) and basilar artery (BA). Measurements of blood flow velocities performed at rest and after the brachial hyperemia test allow one to classify hemodynamic types of SSS. The aim of the study was to categorize types of steal and to compare the differences of flow patterns before and after percutaneous transluminal SA balloon angioplasty (SA-PTA). Fourty-eight patients with angiographically confirmed SSS (aged from 27 to 68 years, mean 53; 2/1 f/m ratio) were examined with 2 MHz range-gated, pulsed transcranial Doppler device (TC 2-64B EME). Both VA and BA were evaluated by the transoccipital approach at rest and during the brachial hyperemia. In 5 cases (10.4%) permanent reversal blood flow in the BA was observed (complete basilar steal). In flow in the BA blood flow was in the normal direction at rest and altered (reversed or decreased) when induced with brachial hyperemia test (transient basilar steal). In the next 14 patients (29.2%) permanently reversed VA blood flow was observed with only a slight or no alterations of the BA flow after the hyperemia test (complete vertebral steal). In the last 19 cases (39.6%) alterations of the VA blood flow without changes in BA flow were observed (latent vertebral steal). Between 1991 and 1994 twenty seven symptomatic patients with different hemodynamic types of SSS were treated with SA-PTA. TCD evaluation of VA's and BA using the hyperemia test was performed before, 3 to 7 days and 3 months after morphologically and hemodynamically successful subclavian artery balloon PTA. Normal results of vertebrobasilar examinations were obtained in 26 cases after this procedure. In one case the latent vertebral steal was detected. The 28 months mean follow-up revealed no significant changes in TCD flow patterns recorded from VA's and BA. After collecting data of about 60 patients with SSS we examined with TCD we conclude that: in patients with a hemodynamically significant SA stenosis the presence of reversed ipsilateral VA blood flow (a radiologic steal) its not a good determinant of either the presence or type of presenting symptoms and after successful PTA or recanalisation and PTA of SA in almost all cases we examined close to normal TCD recordings in BA and VA. 相似文献
50.
文章讨论了OSPF路由协议的扩散算法在多冗余点到点链路情况下存在的缺陷,提出了一种基于扩散接口选举的改进方案。 相似文献