排序方式: 共有74条查询结果,搜索用时 15 毫秒
41.
We introduce multi-scale filtering by the way of certain double convolution systems. We prove stability theorems for these
systems and make connections with function theory in the polydisc. Finally, we compare the framework developed here with the
white noise space framework, within which a similar class of double convolution systems has been defined earlier. 相似文献
42.
A nonparametric deconvolution algorithm for recovering the photon time-of-flight distribution (TOFD) from time-resolved (TR) measurements is described. The algorithm combines wavelet denoising and a two-stage deconvolution method based on generalized singular value decomposition and Tikhonov regularization. The efficacy of the algorithm was tested on simulated and experimental TR data and the results show that it can recover the photon TOFD with high fidelity. Combined with the microscopic Beer-Lambert law, the algorithm enables accurate quantification of absorption changes from arbitrary time-of-flight windows, thereby optimizing the depth sensitivity provided by TR measurements. 相似文献
43.
Gabriel Nguetseng Mamadou Sango Jean Louis Woukeng 《Communications in Mathematical Physics》2010,300(3):835-876
We redefine the homogenization algebras without requiring the separability assumption. We show that this enables one to treat
more complicated homogenization problems than those solved by the previous theory. In particular we exhibit an example of
algebra which, contrary to the algebra of almost periodic functions, induces no homogenization algebra. We prove some general
compactness results which are then applied to the resolution of some homogenization problems related to the generalized Reynolds
type equations and to some nonlinear hyperbolic equations. 相似文献
44.
Mamadou Sango 《Comptes Rendus Mathematique》2006,342(8):563-568
We investigate the Neumann problem for a nonlinear elliptic operator of Leray–Lions type in , , where Ω is a domain in , is a closed set located in the neighborhood of a -dimensional manifold Γ lying inside Ω. We study the asymptotic behavior of as , when the set tends to Γ. To cite this article: M. Sango, C. R. Acad. Sci. Paris, Ser. I 342 (2006). 相似文献
45.
Mamadou Sy Didier Bresch Francisco Guillén-González Jérôme Lemoine Maria Angeles Rodríguez-Bellido 《Comptes Rendus Mathematique》2006,342(3):169-174
We consider a Navier–Stokes type system with a Korteweg stress tensor, coupled with a concentration equation without diffusion. We give a result concerning the local in time existence (and uniqueness) of strong solution for any data (and the global in time existence defined in a interval for fixed if data are small enough), in the case of a bounded domain . To cite this article: M. Sy et al., C. R. Acad. Sci. Paris, Ser. I 342 (2006). 相似文献
46.
47.
Moustapha Dieye Mamadou Abdoul Diop Khalil Ezzinbi 《Mathematical Methods in the Applied Sciences》2017,40(6):2090-2106
In this work, we consider the question of controllability of a class of integrodifferential equations on Hilbert space with measures as controls. We assume that the linear part has a resolvent operator in the sense given by R. Grimmer. We generalize the original work of N. Ahmed on vector measures, and we use it to develop necessary and sufficient conditions for weak and the exact controllability of the integrodifferential equation. Using the latter, we prove that exact controllability of the integrodifferential equation implies exact controllability of a perturbed integrodifferential equation. Controllability problem for the perturbed system is formulated fixed point problem in the space of vector measures. Our results cover impulsive controls as well as regular controls. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
48.
Antimony trichloride has been found to be an efficient and expedient catalyst for the acylation of alcohols, phenols, amines, and sugars with acetic anhydride in high yields and in a short reaction time under solvent‐free conditions at room temperature. Also, racemization of chiral alcohols and epimerization of sugars were not observed in any of the substrates. 相似文献
49.
In order to make reliable predictions of the acid-base properties of macroligands with a large number of ionizable sites such as dendrimers, one needs to develop and validate computational methods that accurately estimate the acidity constants (pKa) of their chemical building blocks. In this article, we couple density functional theory (B3LYP) with a Poisson-Boltzmann continuum solvent model to calculate the aqueous pKa of aliphatic amines, diamines, and aminoamides, which are building blocks for several classes of dendrimers. No empirical correction terms were employed in the calculations except for the free energy of solvation of the proton (H+) adjusted to give the best match with experimental data. The use of solution-phase optimized geometries gives calculated pKa values in excellent agreement with experimental measurements. The mean absolute error is <0.5 pKa unit in all cases. Conversely, calculations for diamines and aminoamides based on gas-phase geometries lead to a mean absolute error >0.5 pKa unit compared to experimental measurements. We find that geometry optimization in solution is essential for making accurate pKa predictions for systems possessing intramolecular hydrogen bonds. 相似文献
50.
Mamadou Moustapha Kanté 《Discrete Applied Mathematics》2007,155(17):2328-2340
We prove that local complementation and vertex deletion, operations from which vertex-minors are defined, can simulate edge contractions. As an application, we prove that the rank-width of a graph is linearly bounded in term of its tree-width. 相似文献