检索结果-南通市图书馆

QP-FREE,TRUNCATED HYBRID METHODS FOR LARGE-SCALE NONLINEAR CONSTRAINED OPTIMIZATION

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 1997年第1期15卷 36-54页

作者： Q. Ni(school of Science, nanjing university of Aeronautics and Astronautics, nanjing, china) 南京航空航天大学研究生院江苏南京

In this paper, a truncated hybrid method is proposed and developed for solving sparse large-scale nonlinear programming problems. In the hybrid method, a symmetric system of linear equations, instead of the usual quadratic programming subproblems, is solved at iterative process. In order to ensure the global convergence, a method of multiplier is inserted in iterative process. A truncated solution is determined for the system of linear equations and the unconstrained subproblems are solved by the limited memory BFGS algorithm such that the hybrid algorithm is suitable to the large-scale problems. The local convergence of the hybrid algorithm is proved and some numerical tests for medium-sized truss problem are given.

关键词： QP-FREE,TRUNCATED HYBRID METHODS FOR LARGE-SCALE NONLINEAR CONSTRAINED OPTIMIZATION II

Luminosity function of optically-selected type II QSOs

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 191-195页

作者： BIAN WeiHao & ZHANG ShiYan Department of Physics,nanjing normal university,nanjing 210097,china Department of Physics Nanjing Normal University Nanjing China

For a sample of 411 type II QSOs with redshifts less then 0.3,we use the Balmer decrements to do the reddening correction of the [O III] luminosities and then derive the intrinsic [O III] luminosity *** find that the host reddening correction of the [O III] 5007 luminosity for type II QSOs cannot be *** median Balmer decrement of Hα/Hβ=4.0 corresponds to an extinction of 0.94 mag for the [O III] 5007 line,which is consistent with the result derived from the median Hβ/Hγ.Comparing the intrinsic luminosity function of type II QSOs with that of type I QSOs,we find that the upper limit of the type II QSO’s fraction in the total QSOs is 80% for type II QSOs with z < 0.3 and 8.6≤log(L[O III]/L)≤9.4.

关键词： type II QSOs luminosity function emission lines Balmer decrements

Calmodulin regulates the post-anaphase reposition of centrioles during cytokinesis

在线全文

学校读者我要写书评

暂无评论

Cell Research 2005年第7期15卷 548-552页

作者： Yue Yue YU, Gu DAI, Fei Yan PAN, Jie CHEN, Chao Jun LI*Jiangsu Key Laboratory for Molecular & Medical Biotechnology, school of Life sciences, nanjing normal university.nanjing 210097, china Jiangsu Key Laboratory for Molecular & Medical Biotechnology School of Life Sciences Nanjing Normal University Nanjing China

A transient postanaphase repositioning of the centriole is found to control the completion of cytokinesis. Using agreen fluorescent protein-calmodulin fusion protein as a living cell probe, we have previously found that calmodulin isassociated with the initiation and progression of cytokinesis. In this study, we further studied the effect of calmodulinon the repositioning of the centriole and subsequent cell cycle progression. When activity of calmodulin is inhibited, theregression of the centriole from the intercellular bridge to the cell center is blocked, and thus the completion of celldivision is repressed and two daughter cells are linked by longer cell bridge in perturbed cells. W7 treatment duringcytokinesis also results in unfinished cytokinesis and stopped G1 phase. These results suggest that calmodulin activity isrequired for centriole repositioning and can affect the completion of cytokinesis and cell cycle progression.

关键词： CaM centriole reposition cytokinesis W7.

A semiparametric Wald statistic for testing logistic regression models based on case-control data

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Mathematics 2008年第11期51卷 2020-2032页

作者： WAN ShuWen Biostatistics Lab, school of Life sciences, nanjing university, nanjing 210093, china Biostatistics Lab School of Life Sciences Nanjing University Nanjing China

We propose a semiparametric Wald statistic to test the validity of logistic regression models based on case-control data. The test statistic is constructed using a semiparametric ROC curve estimator and a nonparametric ROC curve estimator. The statistic has an asymptotic chi-squared distribution and is an alternative to the Kolmogorov-Smirnov-type statistic proposed by Qin and Zhang in 1997, the chi-squared-type statistic proposed by Zhang in 1999 and the information matrix test statistic proposed by Zhang in 2001. The statistic is easy to compute in the sense that it requires none of the following methods: using a bootstrap method to find its critical values, partitioning the sample data or inverting a high-dimensional matrix. We present some results on simulation and on analysis of two real examples. Moreover, we discuss how to extend our statistic to a family of statistics and how to construct its Kolmogorov-Smirnov counterpart.

关键词： case-control data density ratio model empirical likelihood Kolmogorov-Smirnov statistic logistic regression ROC curve 30P12 32C12

AN EQUIVALENCY CONDITION OF NONSINGULARITY IN NONLINEAR SEMIDEFINITE PROGRAMMING

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2010年第4期23卷 822-829页

作者： Chengjin LI Wenyu SUN Raimundo J. B. de SAMPAIO school of mathematical sciences Nanjing Normal and Computer Science Fujian Normal University Wenyu SUN University Nanjing 210046 China school of Mathematics Fuzhou 350007 China school of mathematical sciences Nanjing Normal University Nanjing 210046 China Pontifical Catholic university of Parana ( PUCPR) Graduate Program in Production and Systems Engineering (PPGEPS) CEP 81611-970 Curitiba Parana Brazil

In this paper,an equivalency condition of nonsingularity in nonlinear semidefinite programming,which can be viewed as a generalization of the equivalency condition of nonsingularity for linearsemidefinite programming,... 详细信息

关键词： Equivalency condition of nonsingularity nonlinear semidefinite programming semidefinite programming.

SOME RESULTS ON GENERALIZED DIFFERENCE SETS

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2008年第1期21卷 76-84页

作者： Xiwang CAO school of mathematical Science, nanjing university of Aeronautics and Astronautics, nanjing 210016, china State Key Lab. of Information Security, Beijing 100049, china. school of mathematical Science Nanjing University of Aeronautics and Astronautics Nanjing China State Key Lab. of Information Security China

Sequences with ideal correlation functions have important applications in communications such as CDMA, FDMA, etc. It has been shown that difference sets can be used to construct such sequences. The author extends Pott and Bradley＇s method to a much broader case by proposing the concept of generalized difference sets. Some necessary conditions for the existence of generalized difference sets are established by means of some Diophantine equations. The author also provides an algorithm to determine the existence of generalized difference sets in the cyclic group Zv. Some examples are presented to illustrate that our method works.

关键词： Correlation functions diophantine equations generalized difference sets.

Discrimination of depositional seasonality of tidal flat sediment in northern Jiangsu Province,china

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2001年第S1期46卷 104-107页

作者： WANG Jian, HUANG Qiaohua, XIAO Jiayi, BAI Chunguang, ZHU Xiaohua & CHEN XiaCollege of Geographical sciences, nanjing normal university, nanjing 210097, china College of Geographical sciences Nanjing Normal University Nanjing 210097 China

12 consecutive monthly sediment samples were collected from the tidal flat surface in Dafeng County, Jiangsu province. Palynological analysis of these samples indicates that seasonal palynological features of the tidal flat sediment are distinct and some palynological indices such asspecies percentages of Arboreal and Herbaceous pollen and spore are good indicators for discriminating the depositional seasonality of the tidal flat sediment. Sedimentary sequences formed between 1984 and 1994 were used to verify this method. The result proposes that this method can be applied to muddy flat and the species percentage of arboreal pollen is the best indicator for the seasonality study of the tidal flat sediment.

关键词： seasonal deposition tidal flat sporopollen Jiangsu Province.

A note on periodic solutions for semi-ratio-dependent predator-prey systems

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2010年第1期25卷 1-8页

作者： LIU Xiu-xiang school of mathematical sciences, South china normal university, Guangdong 510631, china school of mathematical sciences South China Normal University Guangdong China

This note investigates the existence of periodic solutions for semi-ratio-dependent predator-prey models with functional response. New sharp criteria without any other nontrivial assumptions are presented by the invariance property of homotopy and analysis technique, which improve and extend many previous work. Some interesting numerical examples are given to illustrate our results.

关键词： Periodic solutions predator-prey system functional response.

B→K~*γ Decay in Top-Quark Two-Higgs-Doublet Model

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2006年第11期46卷 895-900页

作者： XIAO Zhen-Jun,~+ CHENG Hui-Hui, and L Lin-Xia Department of Physics and Institute of Theoretical Physics, nanjing normal university, nanjing 210097, china Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210097 China

By employing the QCD factorization approach for the exclusive B→Vγ decays, we study the exclusive decay B→K~*γ in the top-quark two-Higgs-doublet model (T2HDM). Within the considered parameter space, we find the following conclusions (a) A light charged-Higgs boson with a mass about 200 GeV is clearly excluded by the date of B→K~*γ decay, and this lower limit is comparable with that from the inclusive B→Xγ decay; (b) The theoretical predictions for CP asymmetry of B→K~*γ in the T2HDM is always less than 1% in size; and (c) The isospin symmetry breaking for B→K~*γ decay in the SM and T2HDM considered here is around 6% in size and well consistent with the data and the general expectations.

关键词： B meson decay charged-Higgs boson branching ratio CP asymmetry