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Time to treat the climate and nature crisis as one indivisible global health emergency

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Stroke & Vascular Neurology 2024年第4期9卷 325-327页

作者： Chris Zielinski on behalf of the authorship group listed below Centre for Global Health University of WinchesterWinchesterUK 不详

Over 200 health journals call on the United Nations(UN),political leaders and health professionals to recognise that climate change and biodiversity loss are one indivisible crisis and must be tackled together to pres... 详细信息

关键词： preserve global divisible

Time to treat the climate and nature crisis as one indivisible global health emergency

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Family Medicine and Community Health 2023年第4期11卷 1-3页

作者： Chris Zielinski Centre for Global Health University of WinchesterWinchesterUK

关键词： preserve global divisible

Asymptotic Existence of Nearly Kirkman Systems

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Science China Mathematics 1994年第5期37卷 555-562页

作者：沈灏储文松 Department of Applied Mathematics Shanghai Jiaotong UniversityShanghai 200030PRC

It is proved in this paper that,for any given positive integer k≥2,there exists a constant v0=v0(k) such that for v≥v0,the necessary condition v=0 (mod k(k-)) for the existence of a nearly Kirkman system NKS (2,k,v)... 详细信息

关键词： group divisible design Kirkman system nearly Kirkman system asymptotic existence

Multidimensional compound Poisson distributions in free probability

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Science China Mathematics 2019年第5期62卷 921-934页

作者： Guimei An Mingchu Gao School of Mathematical Sciences and LPMC Nankai University School of Mathematics and Information Science Baoji University of Arts and Sciences Department of Mathematics Louisiana College

Inspired by Speicher's multidimensional free central limit theorem and semicircle families, we prove an in?nite dimensional compound Poisson limit theorem in free probability, and de?ne in?nite dimensional compound free Poisson distributions in a non-commutative probability space. In?nite dimensional free in?nitely divisible distributions are de?ned and characterized in terms of their free cumulants. It is proved that for a sequence of random variables, the following three statements are equivalent:(1) the distribution of the sequence is multidimensional free in?nitely divisible;(2) the sequence is the limit in distribution of a sequence of triangular trays of families of random variables;(3) the sequence has the same distribution as that of {a_1^((i)): i = 1, 2,...}of a multidimensional free L′evy process {{a_1^((i)): i = 1, 2,...} : t≥0}. Under certain technical assumptions, this is the case if and only if the sequence is the limit in distribution of a sequence of sequences of random variables having multidimensional compound free Poisson distributions.

关键词： free probability multidimensional free Poisson distributions multidimensional free infinitely divisible distributions

Simple Minimum(K_4-e)-coverings of Complete Multipartite Graphs

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Acta Mathematica Sinica,English Series 2019年第5期35卷 632-648页

作者： Yu Feng GAO Yan Xun CHANG Tao FENG Institute of Mathematics Beijing Jiaotong University College of Mathematics Tonghua Normal University

A decomposition of K_(n(g))∪Γ, the complete n-partite equipartite graph over gn vertices union a graph Γ(called the excess) that is a subgraph of K_(n(g)), into edge disjoint copies of a graph G is called a simple minimum group divisible covering of type g^n with G if Γ contains as few edges as possible. We examine all possible excesses for simple minimum group divisible(K_4-e)-*** and sufficient conditions are established for their existence.

关键词： Group divisible covering (K4-e)-covering excess graph

The existence spectrum of Meta(K_4^((3))>K_4^((3))-e)

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Science China Mathematics 2010年第11期53卷 2865-2876页

作者： LO FARO Giovanni TRIPODI Antoinette Department of Mathematics University of Messina

Let H and J1 be both t-uniform hypergraphs. Let J2 be a sub-hypergraph of J1. In this paper, the metamorphosis of a hypergraph decomposition is introduced, denoted by (H, J1 > J2)-design, which is a generalization of the concept of metamorphosis of a graph decomposition. Let Meta(J1>J2) denote the set of all integers v such that there exists a (Kv((3)), J1>J2)-design. We completely determine the set Meta(K4((3))>K4((3))-e).

关键词： hypergraph decomposition metamorphosis t-GDD group divisible (Γ t)-design candelabra (Γ t)-system

Simulated Minimum Hellinger Distance Estimation for Some Continuous Financial and Actuarial Models

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Open Journal of Statistics 2017年第4期7卷 743-759页

作者： Andrew Luong Claire Bilodeau école d’actuariat Université Laval Québec Canada

Minimum Hellinger distance (MHD) estimation is extended to a simulated version with the model density function replaced by a density estimate based on a random sample drawn from the model distribution. The method does not require a closed-form expression for the density function and appears to be suitable for models lacking a closed-form expression for the density, models for which likelihood methods might be difficult to implement. Even though only consistency is shown in this paper and the asymptotic distribution remains an open question, our simulation study suggests that the methods have the potential to generate simulated minimum Hellinger distance (SMHD) estimators with high efficiencies. The method can be used as an alternative to methods based on moments, methods based on empirical characteristic functions, or the use of an expectation-maximization (EM) algorithm.

关键词： Infinitely divisible Distribution Mixture Distribution Hellinger Distance Robustness

FURTHER RESULTS ON THE EXISTENCE OF LABELED RESOLVABLE BLOCK DESIGNS

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Journal of Shanghai Jiaotong university(Science) 1999年第2期4卷 52-56页

作者：沈灏沈佳颖

It was proved in this paper that there exists a labeled resolvable block design LRB (4,3; v ) if and only if v ≡0 (mod 4) and v ≥8, with 8 possible exceptions. It was also proved that there exists a nearly Kirkman s... 详细信息

关键词： labeled resolvable block design nearly Kirkman system group divisible design

A Result on Multiply Perfect Number

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Journal of Southeast University(English Edition) 2002年第3期18卷 265-269页

作者：程林凤中国矿业大学数学系徐州221008

Let n be a positive integer satisfying n >1; ω(n) denotes the number of distinct prime factors of n ; σ(n) denotes the sum of the positive divisors of n . If σ(n)=2n then n is said to be a perfect number and if σ(n)=kn(k≥3) then n is said to be a multiply perfect number. In this paper according to Euler theorem and Fermat theorem, we discuss the result of σ(n)=ω(n)n and prove that only n=2 3·3·5, 2 5·3·7, 2 5·3 3·5·7 satisfies σ(n)= ω(n) n(ω(n)≥3). ...

关键词： multiply perfect number Euler theorem divisible