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141.
R Dekker J R van der Meer R Ph Plasmeijer R E Wildeman J J de Bruin 《The Journal of the Operational Research Society》1998,49(2):132-143
This paper discusses several strategies for the maintenance of light-standards, where each light-standard consists of n independent and identical lamps screwed on a lamp assembly. The lamps are subject to stochastic failures, and must be correctly replaced if the number of failed lamps reaches a prespecified number m, a norm that is set by the local management to guarantee a minimum luminance. As lamps have an increasing hazard rate and there is a fixed cost of hoisting the assembly, we propose various variants of the m-failure group replacement rule which have in particular an age-criterion to indicate which of the non-failed lamps must be preventively replaced at the time that the assembly is lowered for a corrective lamp replacement. We show how the optimal threshold age can be determined. It appears that this modification reduces the long run average maintenance cost of the Europe Combined Terminals by approximately 8.3%. 相似文献
142.
Ph. Jacobs 《Journal d'Analyse Mathématique》2000,81(1):343-372
We study the coefficients of asymptotic expansions of oscillating integrals. We also consider the connection with the coefficients
of Laurent expansions at candidate poles of the distribution |f|λ and show that some of these coefficients vanish. Next, we express some of the most important of these coefficients as the
so-called principal value integrals, first introduced by Langlands. Together with our results on principal value integrals,
this leads to new results on the vanishing of these coefficients. 相似文献
143.
Ph. Albert 《Journal of Radioanalytical and Nuclear Chemistry》1980,55(2):453-462
In this article the research topics dealt with at Research Group for Applications of Nuclear Reactions to Chemical Analysis
(GARNAC) are described. Particular emphasis is laid on the main contribution of the GARNAC to the development and the evolution
of charged particle activation analysis, evolving with the analytical studies performed and with the scientific and technical
progress realized in material and semiconductors science.
相似文献
144.
IntroductionTheproblemswithlargegradientarecommoninpracticalengineeringfields,e.g.inmateriallocalization,withinthelocalizatio... 相似文献
145.
We derive asymptotic expansions for tails of infinite weighted convolutions of some heavy-tailed distributions. Applications
are given to tail expansion of the marginal distribution of ARMA processes, randomly stopped sums, as well as limiting waiting
time distribution.
AMS 2000 Subject Classifications. Primary—62E99, Secondary—41A60, 44A35, 60G50, 60K25 相似文献
146.
We classify smooth subvarieties of codimension twoX⊂P
n
, 4≤n≤5, which are arithmetically Cohen-Macaulay and of non general type. By the way we exhibit some classes of non extendable
subvarieties. Then we give new proofs of the classification of scrolls inP
4; finally we consider smooth surfaces of non general type inP
4 arising from rank three vector bundles.
Sunto Classifichiamo le sottovarietà lisce di codimensione dueX⊂P n , 4≤n≤5, aritmeticamente Cohen-Macaulay e non di tipo generale. Nel contempo descriviamo alcune classi di sottovarietà non estendibili. Diamo poi due nuove dimostrazioni della classificazione degli scrolls inP 4; infine consideriamo superfici lisce inP 4, non di tipo generale, associate a fibrati di rango tre.相似文献
147.
IntroductionSincefiniteelementanalysisprogramsdealwiththetheoriesandmethodsofthreefieldsofmechanics,appliedmathematicsandcomputerscience,theyarecomplicatedanderror_prone .Duringdevelopmentpeopleallthroughseekthemethodtoimproveprograms.Theobject_oriente… 相似文献
148.
The problem of the determination at any point P in a body of that pair of infinitesimal material line elements which suffers the maximum shear in a deformation has been
solved [1]. Here that problem is revisited and a short proof, of geometrical type, of the result is presented.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
149.
Peng Cheng Ph.D. Michael A. Sutton Hubert W. Schreier Ph.D. Student Stephen R. McNeill 《Experimental Mechanics》2002,42(3):344-352
A full-field speckle pattern image correlation method is presented that will determine directly the complete, two-dimensional
deformation field during the image correlation process on digital images obtained using computer vision systems. In this work,
a B-Spline function is used to represent the object deformation field throughout the entire image area. This is an improvement
over subset-based image correlation methods by implicitly maintaining position and derivative continuity constraints among
subsets up to a specified order. The control point variables within the B-Spline deformation function are optimized iteratively
with the Levenberg-Marquardt method to achieve minimum disparity between the predicted and actual deformed images. Results
have shown that the proposed method is computationally efficient, accurate and robust. The general framework of this method
can be applied ton-dimensional image correlation systems that solve for multi-dimension vector fields. 相似文献
150.
I. Favero G. Cassabois D. Darson C. Voisin J. Tignon C. Delalande Ph. Roussignol R. Ferreira J. M. Grard 《Physica E: Low-dimensional Systems and Nanostructures》2004,21(2-4):336
We report the first direct observation of Huang–Rhys side-bands in the photoluminescence spectrum of a single InAs/GaAs quantum dot (QD). At low temperature (10 K) the single QD spectrum has a quasi-Lorentzian profile. At higher temperatures, we observe a strong deviation from a Lorentzian profile with the appearance of asymmetric side-bands which become symmetric above 70 K. We obtain an excellent agreement with theoretical calculations done in the framework of the Huang–Rhys formalism. We conclude that the zero-phonon linewidth is the relevant parameter for the observation of the low-energy acoustic phonon side-bands. 相似文献