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Michael Braun 《组合设计杂志》2019,27(11):682-687
An ‐arc in is a set of points such that each line contains at most of the selected points. It is well known that ‐arcs in correspond to projective linear codes. Let denote the maximal number of points for which an ‐arc in exists. In this paper we obtain improved lower bounds on by explicitly constructing ‐arcs. Some of the constructed ‐arcs correspond to linear codes meeting the Griesmer bound. All results are obtained by integer linear programming. 相似文献
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Eric C. Chi Liuyi Hu Arvind K. Saibaba Arvind U. K. Rao 《Journal of computational and graphical statistics》2019,28(1):36-47
We consider the problem of performing matrix completion with side information on row-by-row and column-by-column similarities. We build upon recent proposals for matrix estimation with smoothness constraints with respect to row and column graphs. We present a novel iterative procedure for directly minimizing an information criterion to select an appropriate amount of row and column smoothing, namely, to perform model selection. We also discuss how to exploit the special structure of the problem to scale up the estimation and model selection procedure via the Hutchinson estimator, combined with a stochastic Quasi-Newton approach. Supplementary material for this article is available online. 相似文献
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In this paper, we investigate the complete moment convergence for dependent linear processes with random coefficients to form 相似文献
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Rik H. Verschueren Julie Schmauck Dr. Michael S. Perryman Dr. Hui-Lan Yue Julian Riegger Dr. Bertrand Schweitzer-Chaput Dr. Martin Breugst Dr. Martin Klussmann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(38):9088-9097
In this work, the reactivities of acetonyl and benzoyl radicals in aromatic substitution and addition reactions have been compared in an experimental and computational study. The results show that acetonyl is more electrophilic than benzoyl, which is rather nucleophilic. A Hammett plot analysis of the addition reactions of the two radicals to substituted styrenes clearly support the nucleophilicity of benzoyl, but in the case of acetonyl, no satisfactory linear correlation with a single substituent-related parameter was found. Computational calculations helped to rationalize this effect, and a good linear correlation was found with a combination of polar parameters (σ+) and the radical stabilization energies of the formed intermediates. Based on the calculated philicity indices for benzoyl and acetonyl, a quantitative comparison of these two radicals with many other reported radicals is possible, which may help to predict the reactivities of other aromatic radical substitution reactions. 相似文献
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Verena Bögelein Frank Duzaar Leah Schätzler Christoph Scheven 《Journal of Differential Equations》2019,266(11):7709-7748
We establish that solutions to the Cauchy–Dirichlet problem for functionals of linear growth can be obtained as limits of solutions to flows with p-growth in the limit . The result can be interpreted on the one hand as a stability result. On the other hand it provides an existence result for general flows with linear growth. 相似文献