共33页 河南理工大学本科毕业论文外文文献资料翻译 第 15 页
k?1???limP?max??Xj?EXj????0. n1??,n2??n?k?nm???12j?n1?所以
??Xnn?EXn?尾部收敛到0 a.s.,即??Xn?EXn?收敛,由(i)知?Xn收敛.
nn定理2.1的证明 设Fn?x?是Xn的分布函数,令Yn?XnIXn?bn,I???是示性函数,则
??EXn?Yn2?x2x2??????E?dFx?dFx?????x?bnbn2?b2???x?bnb2nbnpnnnn?n?n于是
p,
EXn?Yn??Yn2?????Var????E?2????pn?bn?n?bn?nbn因此,由定理2.3得,
因为EXn?0,故
p??.
Yn?EYn收敛a.s. (2.5) ?bnn?nEYnbn??n?x?bnxdFn?x?bnx??n?x?bnxdFn?x?bnxppn
???nx?bnbndFn?x????nx?bnbdFn?x?
?由(2.5)和(2.6)知
?nEXnbpnp??. (2.6)
?Ynnbn一致收敛.且
dFn?x????n?P?Xnn?Yn????nxx?bnpx?bnbpndFn?x???nEXnbpnp??
由Borel-Cantelli定理,
?Xnnbn收敛a.s..
?1n应用Kronecker定理,在每一个概率为1的集合上的任意一个样本点?有b?X????0 故有
ii?1nb
?1n?Xi?1ni?0 a.s.
§3 其他线性形式的稳定性
指导教师:李文玲 学生:闻晶晶
共33页 河南理工大学本科毕业论文外文文献资料翻译 第 16 页
在这一节中,我们将给出?-混合随机变量的其他线性形式的稳定性.所有的证明建立在定理2.1的结果中.
定理3.1 设?an??bn?是两列正数,cn?bnan,bn??,?Xn,n?1?是一列?-混合随机变量,
?Xn??X,令N?x??Card?n:cn?x?,x?R.若下列条件满足
(a)EN?X??? (b)
??0tp?1?1?p?2? P?X?t??N?y?yp?1dydt??,t?1n?则存在dn?R N?1,2,??有b?aXii?1ni?dn?0 a.s.
n证明 设Yn?XnIXn?cn,Sn????aX,T??aY,则
iiniii?1i?1?n?1n?P?Xn?1?n?Yn???P?Xn?cn??c?P?X?cn??cEN?X???.
n?1??1?1由Broel-Cantelli引理知:对任意实数列?dn?,bnTn?dn和bnSn?dn在相同的集合上收敛到
????相同的极限.只须证明b?1n?a?Y?EY??0,a.s.就有了定理的diiii?1nn?b?1n?aEY
iii?1n由于?an?Yn?EYn?,n?1?是一列零均值?-混合随机变量且
????l???,得
l?1?
?n?1Ean?Yn?EYn?bnpp?p?c?cnEYnn?1??p
?c?pcn?p?tp?1P?Xn?t?dt
cnn?1`0? ?cp??0tp?1P?X?t??c???n:cn?t?pndt
?cp2最后不等式成立是由于以下事实
?0tp?1P?X?t??N?y?yp?1dydt
tu??n:cn?t??cn?p?limu???n:t?cn?u??cn?p?lim?y?pdN?y?
u??t ?lim?uu?????pN?t??t?pN?t??p?N?y?yp?1dy?
?t?y?u?且
指导教师:李文玲 学生:闻晶晶
共33页 河南理工大学本科毕业论文外文文献资料翻译 第 17 页
u?pN?u??p?N?t?yp?1dy?0,u??
u?由条件(2)和定理2.1即可证得.
定理3.2 如果我们用如下条件替换定理3.1的条件(1)(2): (3)EN?X???; (4)
??1EN?Xs?ds??;
pj(5)maxc1?j?n?cj?n??pj???n?;
?1n此外假定EXn?0,得b?aXii?1ni?0 a.s.
证明:由定理3.1的Yn,Sn,Tn.同理有需须证明bn?P?Xn?1?n?Yn??cEN?X???.为了证明所要的结果只
?1n?1(4)易证b?aY?a?Y?EY??0,a.s..由条件(3)
iiii?1i?1nii?0.这样,我们只需证
b?1n?a?Y?EY??0.
iiii?1因为?an?Yn?EYn??是一列?-混合随机变量且满足(2.3)得
?Ean?Yn?EYn?n?1?p?pb?c?cnEXnI?Xn?cn? ppn?1?? ?c?c?cP?X?c??EXI?X?c??
?pnpnpnnn?1? ?c令dn?maxcj,d0?0,则
1?j?n?pn?P?X?c??c?cnn?1n?1??pnEXpI?X?cn?.
?cn?1??pEXI?X?cn???cEXI?X?dn????cnEXpI?dj?1?X?dj?
p?pnpn?1n?1j?1??n??EXI?dj?1?X?dj??cpj?1n?j???pn??P?dj?1?X?dj?dj?1?pj?cn?j??pn ?c?jP?dj?1?j?1?X?dj??c?P?X?dj?1?j?1?
???????c?1?PX?cj?????j?1??指导教师:李文玲 学生:闻晶晶
共33页 河南理工大学本科毕业论文外文文献资料翻译 第 18 页 由定理2.1得知,b?1n?a?Y?EY??0证毕.
iiii?1n在下文中,令??x?:R??R?为正的不增函数.令an???n?,bn??a,cii?1nn?bnan,
假定(Ⅰ)0?liminfn?1cn??logcn??limsupn?1cn??logcn???;
n??n??(Ⅱ)对x?0,x?logx是不增的. 在条件(Ⅰ)和(Ⅱ)下,我们有如下定理:
定理3.3设?Xn?与EX1?logX1??同分布,则存在dn,使
??????b?1?aXii?1ni?dn?0 a.s.
证明 由an,bn,cn的定义及假定(Ⅱ)知,存在m0?N,??0,??0,对任意n?m0,有
?n?cn??logcn???n.
故cn??n???logcn??,它能确保对任意m?m0都有
?1?cj?m??2j??2?logcm??2m.
仿照定理3.1,令Yn?XnIXn?cn,则当m?m0时,
???Ea?Yjj?m??2j?j?EYj?22b?c?cEXjIXj?cj?c?c?jEX1I?X1?cj?2j?2j22j?mj?m????j??22?c?c?EX1I?X1?cm?1???EX1I?ci?1?X1?ci??j?mi?m?????1??c?cj?m???2j?EX1I?ci?1?X1?ci?2i?m2j???1??c???2i?1?2?logci?EX1I?ci?1?X1?ci?i?m
???1??c?????1??c????根据定理2.1,得到b另一方面,
?2???logc?EXI?c2i1i?m??i?1?X1?ci??2?EX?logX1I?ci?1?X1?ci??1i?m???1n?a?Y?EY??0 a.s.
iiii?1n指导教师:李文玲 学生:闻晶晶
共33页 河南理工大学本科毕业论文外文文献资料翻译 第 19 页
?P?Xi?1?i?Yi???P?Xi?ci??i?1??m0?1i?1?P?Xi?ci???P?Xi?ci?i?m0???m0?1???PXi?log?Xi?ci??logci?i?m0????????
??m0?1???PXi?log?Xi??i??i?m0?由Borel-Cantelli 定理知,定理3.3的结论正确 ,dn?b
?1n?aEY.
iii?1n致谢 作者在此呜谢相关文献作者,他们做出的极有价值的研究.
参考文献
[1] Gan, S.X., Almost sure convergence for ?-mixing random variable sequences, Statist. Prob. L 67(4)(2004), 289-298.
[2] Blum, J.R., Hanson, D.L. and Koopmans, L., On the strong law of large number for a cla stochastic processes, Z. Wahrsch., Verw. Gebiete, 2(1963), 1-11.
[3] Lu, C.Y. and Lin, Z.Y., The Limiting Theory of Mixing-Dependent Random Variables, China demic Press, 1997.
[4] Chung, K.L., A Course in Probability Theory (2nd Ed.), Academic Press, New York, 1974.
指导教师:李文玲 学生:闻晶晶