检索结果-南通市图书馆

On the behavior of the product of independent random variables

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2006年第3期49卷 342-359页

作者： su chun CHEN Yu Department of Statistics and Finance University of Science and Technology of China Hefei 230026 China Department of Statistics and Finance University of Science and Technology of China Hefei 230026 China

For two independent non-negative random variables X and Y, we treat X as the initial variable of major importance and Y as a modifier (such as the interest rate of a portfolio).Stability in the tail behaviors of the product compared with that of the original variable X is of practical interests. In this paper, we study the tail behaviors of the product XY when the distribution of X belongs to the classes L and S, respectively. Under appropriate conditions, we show that the distribution of the product XY is in the same class as X when X belongs to class L or S, in other words, classes L and S are stable under some mild conditions on the distribution of Y. We also show that if the distribution of X is in class L(γ) (γ＞ 0) and continuous, then the product XY is in L if and only if Y is unbounded.

关键词： independent product, stability, tails of a distribution, heavy-tailed.

Precise Asymptotics for Lévy Processes

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2007年第7期23卷 1265-1270页

作者： Zhi Shui HU chun su Department of Statistics and Finance University of Science and Technology of China

Let {X（t）, t ≥ 0} be a Lévy process with EX（1） = 0 and EX^2（1）〈 ∞. In this paper, we shall give two precise asymptotic theorems for {X（t）, t 〉 0}. By the way, we prove the corresponding conclusions for s... 详细信息

关键词： precise asymptotic Lévy process stable process Fuk-Nagaev type inequality

Precise large deviations for generalized dependent compound renewal risk model with consistent variation

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mathematics in China 2014年第1期9卷 31-44页

作者： Yu CHEN Weiping ZHANG chun su Department of Statistics and Finance School of Management University of Science and Technology of China Hefei 230026 China

We investigate the precise large deviations of random sums of negatively dependent random variables with consistently varying tails. We find out the asymptotic behavior of precise large deviations of random sums is insensitive to the negative dependence. We also consider the generalized dependent compound renewal risk model with consistent variation, which including premium process and claim process, and obtain the asymptotic behavior of the tail probabilities of the claim surplus process.

关键词： Negative dependence precise large deviation random sum consistently varying tail

Branching structure of uniform recursive trees

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2005年第6期48卷 769-784页

作者： FENG Qunqiang su chun HU Zhishui Department of Statistics and Finance University of Science and Technology of China Hefei 230026 China Department of Statistics and Finance University of Science and Technology of China Hefei 230026 China Department of Statistics and Finance University of Science and Technology of China Hefei 230026 China

The branching structure of uniform recursive trees is investigated in this *** the method of sums for a sequence of independent random variables, the distribution law of ηn, the number of branches of the uniform recursive tree of size n are given first. It is shown that the strong law of large numbers, the central limit theorem and the law of iterated logarithm for ηn follow easily from this method. Next it is shown that ηn and ξn, the depth of vertex n, have the same distribution, and the distribution law of ζn,m, the number of branches of size m, is also given, whose asymptotic distribution is the Poisson distribution with parameter λ = 1/m. In addition, the joint distribution and the asymptotic joint distribution of the numbers of various branches are given. Finally, it is proved that the size of the biggest branch tends to infinity almost sure as n -→∞.

关键词： uniform recursive tree, branch, depth, distribution law, limit theorem.

Convergence in the law of logarithm for NA sequences

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第15期44卷 1356-1360页

作者： Hanying Liang chun su Univ Sci & Technol China Dept Stat & Finance Hefei 230026 Peoples R China

Some results in the law of logarithm for NA sequences are obtained, which are similar to the result of id random variables; as a corollary, a sufficient result for the bounbed law of logarithm for NA arrays is given. Meanwhile, A conjecture for id random variables of Gut is answered in NA setting. Under weaker moment conditions than su and Qin’s, a stronger convergence resuit than their Theorem 1 is obtained.

关键词： NA sequence law of logarithm convergence.

Binary digit representation of moments for maximum partial sums of random variables and applications

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第22期44卷 2037-2040页

作者： chun su Xiang Chi Univ Sci & Technol China Dept Stat & Finance Hefei 230026 Peoples R China

Binary digit representation of partial sums for random variables has been investigated, and a good upper bound of moments of maximum partial sums for random variables has been reduced by using this representation. As an applications, stability and strong law of large numbers have been discussed. Many known classical results have been refined.

关键词： arbitrary random variable binary digit representation maximum partial sum moment inequality.

Limiting theorems for the nodes in binary search trees

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2008年第1期51卷 101-114页

作者： LIU Jie su chun CHEN Yu Department of Statistics and Finance University of Science and Technology of ChinaHefei 230026China

We consider three random variables X_n, Y_n and Z_n, which represent the numbers of the nodes with 0, 1, and 2 children, in the binary search trees of size n. The expectation and variance of the three above random variables are got, and it is also shown that X_n, Y_n and Z_n are all asymptotically normal as n→∞by applying the contraction method.

关键词： binary search tree nodes law of large numbers contraction method limiting distribution 60F05 05C80

The Effect of Planting Oilseed Rape and Compost Application on Heavy Metal Forms in Soil and Cd and Pb Uptake in Rice

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2011年第2期10卷 267-274页

作者： WU Fei-long LIN Dai-yan su De-chun College of Resources and Environmental Sciences China Agricultural UniversityBeijing 100193P.R.China Institute of Agricultural Engineering Fujian Academy of Agricultural SciencesFuzhou 350013P.R.China

Pot experiments were conducted under greenhouse condition to investigate whether Cd and Pb uptake by rice could be reduced when it was rotated with oilseed rape and compost *** results showed that the rice grown after oilseed rape had significantly lower Cd and Pb concentrations in both straw and *** and Pb concentrations in the grains of the rice rotated with oilseed rape decreased by approximately 46-80% and 17-86%,respectively,although the Cd and Pb removal by oilseed rape ranged only from 2.39-3.67 and 0.032-0.13% of the total content in *** amendment also decreased the bioavailability of Cd and Pb in the soil and reduced Cd and Pb uptake by oilseed rapes and *** concentrations of Cd and Pb significantly decreased in the exchangeable and carbonate fractions and Pb concentration decreased in the organic matter and sulfide fractions in the contaminated soil after planting oilseed rapes.

关键词： heavy metal crop rotation compost oilseed rape rice

Synthesis and optical activity of isosorbide chiral derivative containing fluorocarbon group as chiral dopant in liquid crystal materials

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2011年第12期22卷 1447-1450页

作者： Kong Liang Xie Yin He su chun Xiang Zhang College of Chemistry Chemical Engineering and Biotechnology Donghua University Shanghai 201620 China

Novel isosorbide derivative containing perfluorocarbon group,bi（perfluorooctanesulfonyl）isosorbide ester as chiral dopant in liquid crystal,was *** structure was characterized by elemental analysis,FT-IR,~1H NMR and ^（19）F *** optical texture of the mixture was observed by polarized optical microscopy（POM）.Novel chiral dopant containing perfluorocarbon group had excellent optical *** specific rotation and molar rotation were noticeable higher than those of bi（4-chloromethylbenzenecarbonic）isosorbide *** fluorocarbon group improved the molar rotation of chiral compound and did not affect optical rotation *** texture of the mixture added isosorbide derivative with fluorocarbon group showed the oily streak texture.

关键词： Optical properties surfaces Texture Liquid crystal Fluorocarbon