关于离散时间马氏链的一些注记

常返性的判别和平稳分布存在性是离散时间马氏链的重要研究内容．通过对转移概率极限存在性的判定，给出了离散时间马氏链常返性的一个充分且必要条件，在此基础上给出了一个判断马氏链平稳分布是否存在的简单定理．     

Cayley树指标集马氏链的射线常返性

给出了Cayley树边界TC,2的集合形式,研究在不限定根顶点O的条件下,Cayley树指标集马氏链的射线常返性,得出了Cayley树指标集马氏链或者强常返,或者非常返的结论。     

随机环境中马氏链的常返与强常返

本文给出了随机环境中马氏链的特征数的定义，讨论了在可这条件下常返与强常返等的相互关系。部分推广了经典马氏链的相应结果。     

三状态齐次马氏链

三状态齐次马氏链是比较简单的马氏链,但马氏链理论的所有基本问题在这种简单情形下都有其反映。三状态齐次马氏链的性质由其(一步)转移矩阵完全决定,因而关于状态的周期、常返性、状态之间的互通性等等基本问题都应当利用转移矩阵本身来作出回答。本文将要给出关于这些问题的一系列的判定准则,我们的条件都加在转移矩阵上,直接用转移矩阵的元素来表述,因而十分简洁且便于应用。值得指出的是,我们的方法亦适用于状态更多的有限马氏链,只是随着状态数目的增加,条件将变得十分复杂。就这个意义而言,对于有限马氏链,三状态情形是非常典型的。     

一类随机环境中单边二重随机游动的常返性

随机环境中的单边二重随机游动是随机环境中随机游动的推广,讨论了随机环境中单边二重随机游动的常返性.在环境满足一定的条件下给出二重随机游动的常返、正常返、零常返和非常返的判别准则.     

随机环境中马氏链的状态性质

利用马氏链的一般理论和Foguel的L1理论讨论了随机环境中马氏链正则本质状态的性质,同时得到了状态强常返的一个充分条件。     

随机环境中的马氏链状态分类的几点注记

本文给出了随机环镜中马氏链的特征数和状态的定义,讨论了状态间的传递性,自反性,对称性,是经典马氏链相应结果的一般化,并运用位势方法研究了状态间的关系,它们在极限理论的研究中非常有用。     

谈谈简单随机游动

本文介绍了简单随机游动的分布,常返性和暂留性,首中时及其分布。     

谈谈简单随机游动

本文介绍了简单随机游动的分布、常返性和暂留性、首中时及其分布。     

两参数宽过去马氏过程的强马氏性

定义了一类两参数宽过去马氏过程的强马氏性,给出了满足强马氏性的一个充分条件,研究了此类强马氏过程的一些性质.     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

胡主席在印度,我却在中国

Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.