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971.
972.
We continue the study of the linear complexity of binary sequences, independently introduced by Sidel’nikov and Lempel, Cohn,
and Eastman. These investigations were originated by Helleseth and Yang and extended by Kyureghyan and Pott. We determine
the exact linear complexity of several families of these sequences using well-known results on cyclotomic numbers. Moreover,
we prove a general lower bound on the linear complexity profile for all of these sequences. 相似文献
973.
本文给出单状态变量的局部分岔问题中一类具有有限余维数的理想中最大内蕴理想的计算公式并且得到关于内蕴理想的两个充分必要条件. 相似文献
974.
A Frisch-Newton Algorithm for Sparse Quantile Regression 总被引:3,自引:0,他引:3
RogerKoenker PinNg 《应用数学学报(英文版)》2005,21(2):225-236
Recent experience has shown that interior-point methods using a log barrier approach are far superior to classical simplex methods for computing solutions to large parametric quantile regression problems. In many large empirical applications, the design matrix has a very sparse structure. A typical example is the classical fixed-effect model for panel data where the parametric dimension of the model can be quite large, but the number of non-zero elements is quite small. Adopting recent developments in sparse linear algebra we introduce a modified version of the Prisch-Newton algorithm for quantile regression described in Portnoy and Koenker~([28]). The new algorithm substantially reduces the storage (memory) requirements and increases computational speed. The modified algorithm also facilitates the development of nonparametric quantile regression methods. The pseudo design matrices employed in nonparametric quantile regression smoothing are inherently sparse in both the fidelity and roughness penalty components. Exploiting the sparse structure of these problems opens up a whole range of new possibilities for multivariate smoothing on large data sets via ANOVA-type decomposition and partial linear models. 相似文献
975.
借助于光滑模ωψ^rλ(f,t)(0≤λ≤1)给出了Bernstein算子线性组合同时逼近的点态结果。 相似文献
976.
本文给出了一类带参数2n阶非对称微分算子Aλ的一些正则性定理,籍此可刻画一类飞行器在其运行过程中的双向平稳行为. 相似文献
977.
978.
张连平 《高校应用数学学报(A辑)》2002,17(3):318-322
本文给出例子,说明离散算子本征投影一致有界推不出其本征幂零一致,有界幂零一致有界也推不出本征幂零的幂一致有界。 相似文献
979.
Gautam Mitra Cormac Lucas Shirley Moody Bjarni Kristjansson 《Computational Optimization and Applications》1995,4(3):263-283
LP models are usually constructed using index sets and data tables which are closely related to the attributes and relations of relational database (RDB) systems. We extend the syntax of MPL, an existing LP modelling language, in order to connect it to a given RDB system. This approach reuses existing modelling and database software, provides a rich modelling environment and achieves model and data independence. This integrated software enables Mathematical Programming to be widely used as a decision support tool by unlocking the data residing in corporate databases. 相似文献
980.
Recently, Freund and Nachtigal proposed the quasi-minimal residual algorithm (QMR) for solving general nonsingular non-Hermitian linear systems. The method is based on the Lanczos process, and thus it involves matrix—vector products with both the coefficient matrix of the linear system and its transpose. Freund developed a variant of QMR, the transpose-free QMR algorithm (TFQMR), that only requires products with the coefficient matrix. In this paper, the use of QMR and TFQMR for solving singular systems is explored. First, a convergence result for the general class of Krylov-subspace methods applied to singular systems is presented. Then, it is shown that QMR and TFQMR both converge for consistent singular linear systems with coefficient matrices of index 1. Singular systems of this type arise in Markov chain modeling. For this particular application, numerical experiments are reported. 相似文献