首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
研究两种混合系数线性模型Zij=[x(tij)]'α+[y(tij)]'βi+εij(i=1,2,…,m;j=1,2,…,ni;ni>p+q)和Zi=Cid+ei(i=1,2,…,m,eii.i.d(0,YiΣY'i+σ2Ini))参数估计的容许性,可视为一种小样本理论。  相似文献   

2.
通过研究集合S={ 1,2 ,… ,n}上变换σ的动力系统性质 :(1)得到了σ的标准分解式 :σ =(q11q12 …q1t1 ) ∧ (q2 1q2 2 …q2t2 ) ∧ … (qm1qm2 …qmtm) ∧ (j11j12 …j1n1 ) (j2 1j2 2 …j2n2 )… (jk1jk2 …jknk) ;(2 )证明了 :|H n | =∑ni =0Cin(n-i) i(n-i) ! ,其中H n ={σ∈Hn|σk+ 1=σ ,k =1,2 ,3,… } .  相似文献   

3.
n(n≥2)条长为2的路具有两个共同的端点的二分图记为A(n)=(X,Y,E),其中X为2n度顶点集合,y为2度顶点集合,记X={u1,u2},y={v0,v1,…,vn-1},A(nj)=(Xj,Yj,Ej)(nj≥2)中的Xj={v1j,v2j},Yj={v1j,v2j,…,vnjj-1}(j=1,2,…,m),用一条边连接vnjj-1与u2j+1(j=1,2,…,m-1)得到的图记为∧mj=1A(nj).图∪ni=1∧mij=1A(nj)是n个∧mij=1A(nj)的不交并,本文证明了∪ni=1∧mij=1A(nj)是优美的且是交错的.  相似文献   

4.
n(n≥2)条长为2的路具有两个共同的端点的二分图记为A(n)=(X,Y,E),其中X为2n度顶点集合,Y为2度顶点集合,记X={u1,u2},y=v0,v1,…,vn-1,A(nj)=(Xj,Yj,Ej)(nj≥2)中的Xj={uj1,uj2},Yj={vj1,vj2,…,vjnj-1}(j=1,2,…,m),用一条边连接vjnj-1与uj2+1(j=1,2,…,m-1)得到的图记为∧from j=1 to m A(nj).图∪from i=1 to n ∧from j=1 to m_i A(n_j)是n个∧from j=1 to m_i的不交并.本文证明了∪from i=1 to n ∧from j=1 to m_i A(n_j)是优美的且是交错的.  相似文献   

5.
设X=(X_1,X_2,…,X_n)′~N_n(∑β,∑),其中β∈R~n,∑=(σ_(ij))。如果β的所有分量同时非负或同时非正,且存在对角元取值±1的对角矩阵D使得-DΣ~(-1)D的非对角元元素非负,则P[|X_j|相似文献   

6.
讨论多时滞一阶非线性微分方程组dxi(t)/dt mΣj=1aij(t)fij(xj(t-τj(t)))=0,i=1,2,…,m. 的所有解振动的充分条件.同时我们也得到了多时滞LOGISTIC方程组dNi(t)/dt=Ni(t)[ai-mΣj=1bijNj(t-τj)],i=1,2,…,m.的所有正解关于它的平衡点振动的充分条件.  相似文献   

7.
设{Xi;i≥1}是一严平稳零均值PA随机变量序列,EX12>0,σ2=EX12 2∑∞j=2EX1Xj,并且0<σ2<∞.令Sn=∑ni=1Xi,n≥1.利用部分和Sn的弱收敛定理,证明了当ε→0时,∑∞n=1(logn)δnP{Sn≥εnlogn}的精确渐近性成立.  相似文献   

8.
EV线性模型参数的经验似然比置信区域   总被引:2,自引:1,他引:1  
考虑EV(error in variables) }线性模型 Yi =xτiβ0 +εi,Xi =xi+ μi, i=1,2 ,… ,n ,其中εi 是i.i.d .的具有均值 0和连续可导的分布函数的误差 ,Xi 为 p维可观测随机向量 ,xi 为 p维不可观测随机向量 ,β0 为 p× 1未知参数向量 ,μi 是 p维i.i.d .的不可观测随机误差 .记 ei =(εi,μτi) τ,且Eei=0 ,Σee=σ2 Ip+ 1.设xj与ei对所有的i,j都是独立的 .在一般的条件下证明了非参数形式的Wilks theorem在EV线性模型中的正确性 ,并利用它构造出了 β0 的置信区域 ,然后在小样本下给出了模拟结果 .  相似文献   

9.
具连续变量线性脉冲时滞差分方程的振动性   总被引:2,自引:0,他引:2  
研究具连续变量的脉冲时滞差分方程{y(t)-y(t-τ) m∑j=1pj(t)y(t-σj)=0,t≠tk,y(tk^ )-y(tk)=bky(tk),k=1,2,…得到了方程所有解振动的若干充分性条件。}  相似文献   

10.
文章得到了二阶非线性中立型微分方程[a(t)x(t)-∑mi=1bi(t)x(t-τi)]″-∑lj=1Pj(t)fj(t,x(t-σj))=0,t>t0,和相对应的不等式[a(t)x(t)-∑mi=1bi(t)x(t-τi)]″-∑lj=1Pj(t)fj(t,x(t-σj))≥0,t>t0,存在最终有界正解是等价的,其中τi>0,σj≥0,a(t),bi(t),Pj(t)∈C([t0,∞],R ),(i=1,2,…,m,j=1,2,…,l),当t充分大时,Pj(t)不恒等于零,fj(t,u)是关于u的单调不减的实函数,且当u>0时,fj(t,u)>0,(j=1,2,…,l).  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号