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41.
Vilijandas Bagdonavičius Ruta Levuliene Mikhail Nikulin 《Comptes Rendus Mathematique》2004,339(6):425-428
We propose two tests to test the hypothesis of the equality of two survival functions against the alternative of crossing of these functions for right-censured data. The asymptotic laws of test statistics are given. The powers of the tests are calculated. To cite this article: V. Bagdonavi?ius et al., C. R. Acad. Sci. Paris, Ser. I 339 (2004). 相似文献
42.
Ruta J Ravelet C Baussane I Fize J Décout JL Peyrin E 《Journal of separation science》2008,31(12):2239-2243
In this paper, we describe an aptamer-based competitive affinity CE (ACE) assay involving (i) the pre-incubation of the target (D-arginine) and the specific ligand (anti-D-arginine-L-RNA aptamer) before (ii) the competition with the labeled target (dansylated D-arginine) through an on-capillary mixing strategy. The effects of some critical operating parameters such as the applied voltage and the sample-aptamer mixture plug length on the assay sensitivity were investigated. The ACE assay appeared particularly dependent on the plug length of the pre-incubated sample-aptamer solution. It was shown that this "hybrid" strategy significantly improved the assay sensitivity relative to that obtained with a "full" on-capillary mixing approach. 相似文献
43.
This paper presents the analysis of linear elastic trusses proposed by Valentino Cerruti in his graduation thesis. While Cerruti
is famous among rational mechanicians, very little is known on this work of his. We will consider the work in some detail,
putting into evidence the main subjects dealt with by the author: redundant trusses and uniform resistance. We will also provide
a comparison with his contemporaries and some critical comments. 相似文献
44.
This paper presents the theorem proposed by Luigi Federico Menabrea to study linear elastic redundant systems. Some of Menabrea’s
papers on the subject are examined, as well as the criticism and the corrections brought to his first proof. We consider Menabrea’s
work in the frame of the studies of his contemporaries; we try to provide a historical and epistemological background for
Menabrea’s theorem and for its consequences in modern mechanics. 相似文献
45.
New trends in fast and high-resolution liquid chromatography: a critical comparison of existing approaches 总被引:1,自引:0,他引:1
Davy Guillarme Josephine Ruta Serge Rudaz Jean-Luc Veuthey 《Analytical and bioanalytical chemistry》2010,397(3):1069-1082
Recent developments in chromatographic supports and instrumentation for liquid chromatography (LC) are enabling rapid and
highly efficient separations. Various analytical strategies have been proposed, for example the use of silica-based monolithic
supports, elevated mobile phase temperatures, and columns packed with sub-3 μm superficially porous particles (fused core)
or with sub-2 μm porous particles for use in ultra-high-pressure LC (UHPLC). The purpose of this review is to describe and
compare these approaches in terms of throughput and resolving power, using kinetic data gathered for compounds with molecular
weights ranging between 200 and 1300 g mol−1 in isocratic and gradient modes. This study demonstrates that the best analytical strategy should be selected on the basis
of the analytical problem (e.g., isocratic vs. gradient, throughput vs. efficiency) and the properties of the analyte. UHPLC
and fused-core technologies are quite promising for small-molecular-weight compounds, but increasing the mobile phase temperature
is useful for larger molecules, for example peptides. 相似文献
46.
47.
Virgilijus Uloza Antanas Verikas Marija Bacauskiene Adas Gelzinis Ruta Pribuisiene Marius Kaseta Viktoras Saferis 《Journal of voice》2011,25(6):700-708
Objectives
The aims of the present study were to evaluate the accuracy of an elaborated automated voice categorization system that classified voice signal samples into healthy and pathological classes and to compare it with classification accuracy that was attained by human experts.Material and Methods
We investigated the effectiveness of 10 different feature sets in the classification of voice recordings of the sustained phonation of the vowel sound /a/ into the healthy and two pathological voice classes, and proposed a new approach to building a sequential committee of support vector machines (SVMs) for the classification. By applying “genetic search” (a search technique used to find solutions to optimization problems), we determined the optimal values of hyper-parameters of the committee and the feature sets that provided the best performance. Four experienced clinical voice specialists who evaluated the same voice recordings served as experts. The “gold standard” for classification was clinically and histologically proven diagnosis.Results
A considerable improvement in the classification accuracy was obtained from the committee when compared with the single feature type-based classifiers. In the experimental investigations that were performed using 444 voice recordings coming from 148 subjects, three recordings from each subject, we obtained the correct classification rate (CCR) of over 92% when classifying into the healthy-pathological voice classes, and over 90% when classifying into three classes (healthy voice and two nodular or diffuse lesion voice classes). The CCR obtained from human experts was about 74% and 60%, respectively.Conclusion
When operating under the same experimental conditions, the automated voice discrimination technique based on sequential committee of SVM was considerably more effective than the human experts. 相似文献48.
Meccanica - The behaviour of pre-twisted and tapered beams (such as turbine or helicopter blades) is characterized by stress distributions that may be quite different from those of the usual beam... 相似文献
49.
Ruta Lazauskaite Maryte Daskeviciene Vytautas Getautis Juozas V. Grazulevicius 《Monatshefte für Chemie / Chemical Monthly》2009,10(2):565-571
Abstract
Photoinitiated cationic polymerizations of various epoxy monomers bearing a carbazole moiety, 9-[3-(allyloxy)-2-(oxiran-2-ylmethoxy)propyl]-9H-carbazole, 9-[3-methoxy-2-(oxiran-2-ylmethoxy)propyl]-9H-carbazole, 9-[2-(oxiran-2-ylmethoxy)ethyl]-9H-carbazole, as well as a composition of 3,6-dibromo-9-(oxiran-2-ylmethyl)-9H-carbazole with 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate were investigated in bulk using triphenyl carbenium salts having anions such as BF4 −, SnCl5 −, and SbCl6 −. Dark polymerizations of the carbazolyl monomers in the presence of the initiators are studied. These photoinduced polymerization reactions give oligomers of degree of polymerization 4-22. The effect of the anion of the photoinitiator and polymerization time on the polymerization reaction is discussed. 相似文献50.
We use Signorini's expansion to analyse deformations of a straight, prismatic, isotropic, stress free, homogeneous body made
of a second-order elastic material and loaded as follows. It is first twisted by an infinitesimal amount and then loaded by
applying surface tractions, with nonzero resultant forces and/or moments, only at its end faces. The centroid of one end face
is taken to be rigidly clamped. By using a semi-inverse method, the problem is reduced to that of solving two plane elliptic
problems involving six arbitrary constants that characterize flexure, bending, extension, and torsion superimposed upon the
infinitesimal twist. It is shown that the Clebsch hypothesis is not valid for this problem. A second-order Poisson's effect,
not of the Saint-Venant type, and generalized Poynting effects may also occur in these problems.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献