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131.
Gaëlle Semard Valerie Peulon-Agasse Auguste Bruchet Jean-Philippe Bouillon Pascal Cardinaël 《Journal of chromatography. A》2010,1217(33):5449-5454
It is important to develop methods of optimizing the selection of column sets and operating conditions for comprehensive two-dimensional gas chromatography. A new method for the calculation of the percentage of separation space used was developed using Delaunay's triangulation algorithms (convex hull). This approach was compared with an existing method and showed better precision and accuracy. It was successfully applied to the selection of the most convenient column set and the geometrical parameters of second column for the analysis of 49 target compounds in wastewater. 相似文献
132.
The variable returns to scale data envelopment analysis (DEA) model is developed with a maintained hypothesis of convexity in input–output space. This hypothesis is not consistent with standard microeconomic production theory that posits an S-shape for the production frontier, i.e. for production technologies that obey the Regular Ultra Passum Law. Consequently, measures of technical efficiency assuming convexity are biased downward. In this paper, we provide a more general DEA model that allows the S-shape. 相似文献
133.
We give a new approach, inspired by Hörmander?s L2-method, to weighted variance inequalities which extend results obtained by Bobkov and Ledoux. It provides in particular a local proof of the dimensional functional forms of the Brunn–Minkowski inequalities. We also present several applications of these variance inequalities, including reverse Hölder inequalities for convex functions, weighted Brascamp–Lieb inequalities and sharp weighted Poincaré inequalities for generalized Cauchy measures. 相似文献
134.
Given a monotone convex function on the space of essentially bounded random variables with the Lebesgue property (order continuity), we consider its extension preserving the Lebesgue property to as big solid vector space of random variables as possible. We show that there exists a maximum such extension, with explicit construction, where the maximum domain of extension is obtained as a (possibly proper) subspace of a natural Orlicz-type space, characterized by a certain uniform integrability property. As an application, we provide a characterization of the Lebesgue property of monotone convex function on arbitrary solid spaces of random variables in terms of uniform integrability and a “nice” dual representation of the function. 相似文献
135.
Juan Enrique Martínez-Legaz Maxim Ivanov Todorov Carlos Armando Zetina 《Numerical Functional Analysis & Optimization》2014,35(7-9):1078-1094
In this article, we extend the definition of γ-active constraints for linear semi-infinite programming to a definition applicable to convex semi-infinite programming, by two approaches. The first approach entails the use of the subdifferentials of the convex constraints at a point, while the second approach is based on the linearization of the convex inequality system by means of the convex conjugates of the defining functions. By both these methods, we manage to extend the results on γ-active constraints from the linear case to the convex case. 相似文献
136.
We consider the convex composite problem of minimizing the sum of a strongly convex function and a general extended valued convex function. We present a dual-based proximal gradient scheme for solving this problem. We show that although the rate of convergence of the dual objective function sequence converges to the optimal value with the rate O(1/k2), the rate of convergence of the primal sequence is of the order O(1/k). 相似文献
137.
该文得到了凸度量空间上混合映射的共同点的一些结果.推广了Ciric在文献[3]中的结论. 相似文献
138.
M. Tezer-Sezgin S. Han Aydin 《International Journal of Computational Fluid Dynamics》2013,27(1):49-63
A dual reciprocity boundary element method is given to obtain the solution in terms of velocity and induced magnetic field for the study of MHD (magnetohydrodynamic) flow through a rectangular duct having insulating walls. The equations are transformed to two types of nonlinear Poisson equations and the right-hand sides in these equations are approximated using combinations of two classes of radial basis functions (the value of the function and its normal derivatives are utilized for approximation). Computations are carried out for several values of the Hartman number (0 h M h 10) by using constant boundary elements. Comparisons are made for two types of formulations and for traditional and osculatory type approximations of the right-hand side functions. It is found that osculatory interpolation gives better results than traditional interpolation and the type of the Poisson equation, which contains derivative of the unknown function, is better than the other type, which contains unknown function only. The results for velocity and induced magnetic field are illustrated by some selected graphs. 相似文献
139.
We characterize the convex envelope of a given function f as the unique solution of a convex programming problem. It allows us to build a sequence of convex and polygonal function
un
that converges uniformly to the convex envelope of f. 相似文献
140.
Pierre Cardaliaguet 《Journal of Mathematical Analysis and Applications》2011,381(1):43-63
We consider the Monge transportation problem when the cost is the squared geodesic distance around a convex obstacle. We show that there exists at least one—and in general infinitely many—optimal transport maps. 相似文献