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 578 毫秒
1.
Banach空间中关于增生算子方程解带误差的Ishikawa迭代序列   总被引:1,自引:1,他引:0  
设X是任意实Banach空间,T:X→X是Lipschitz连续的增生算子,在没有假设∞∑n=0αnβn<∞之下,证明了由xn 1=(1-αn)xn αn(f-Tyn) un及yn=(1-βn)xn βn(f-Txn) vn,(A)n≥0生成的、带误差的Ishikawa迭代序列强收敛到方程x Tx=f的唯一解,并给出了更为一般的收敛率估计:若un=vn=0,(A)n≥0,则有‖xn 1-x*‖≤(1-γn)‖xn-x*‖≤…≤n∏j=0(1-γj)‖x0-x*‖,其中{yn}是(0,1)中的序列,满足γn≥[1/2max{η,1-η}-1/4min{η,1-η}]αn,(A)n≥0.  相似文献   

2.
Banach空间上广义渐近拟非扩张型映象不动点的逼近   总被引:7,自引:4,他引:3  
引入一类比渐近拟非扩张型映象更加广泛的广义渐近拟非扩张型映象,并给出具混合误差的Ishikawa迭代序列强收敛于广义渐近拟非扩张型映象的一个不动点的充要条件:设E是一Banach空间,T:E→E是广义渐近拟非扩张型映象,其渐近系数kn满足∑(kn-1)<∞;若T在F(T)中的点处一致连续,任取一点x0∈E,{xn}是由下式定义的具混合误差的Ishikawa迭代序列{xn 1=(1-αn)xn αnTnyn un, ,yn=(1-βn)xn βnTnxn vn,n≥0其中{αn}、{βn}是[0,1]中的两个数列且∞∑n=0αn收敛,{un}、{vn}是E中两个点列且{vn}有界同时∞En=0‖un‖收敛.则{xn}强收敛于T在E中一个不动点的充要条件是lim inf D(xn,F(T))=0.  相似文献   

3.
关于一致凸Banach空间的注记   总被引:1,自引:2,他引:1  
给出了Banach空间一致凸的几个新的充要条件.定理 设10,存在δ>0,使得当‖x‖≤1,‖y‖≤1,‖x-y‖≥ε时,有‖λx+μy‖≤1-δ   对任意满足‖xn‖≤1,‖yn‖≤1,limn∞‖λxn+μyn‖1的序列{xn},{yn}都有limn∞‖xn-yn‖=0   对任意ε>0,存在δ>0,使得当‖x‖≤1,‖x-y‖≥ε时,有‖λx+μy‖p<λ‖x‖p+μ‖y‖p-δ  相似文献   

4.
设X是一实Banach空间,T∶X→X是Lipschitz连续的增生算子,在没有假设∑∞n=0αnβn<∞之下,本文证明了由xn 1=(1-αn)xn αn(f-Tyn) un以yn=(1-βn)xn βn(f-Txn) vn,n≥0产生的带误差的Ishikawa迭代序列强收敛到方程x Tx=f的唯一解,并给出了更为一般的收敛率估计:若un=vn=0,n≥0,则有‖xn 1-x*‖≤(1-αn)‖xn-x*‖≤…≤∏in=0(1-αj)‖xn-x*‖,其中{αn}是(0,1)中的序列,满足γn≥4ηL(L 1)αn,n≥0。  相似文献   

5.
目的 研究Hilbert空间H上的Hilbert基、Bessel基、Riesz基三者间的关系,及其与Bessel列、小波Ricsz基的关系.方法 算子论方法 .结果 证明了对于Hilberr空间日的任一Schuder基{xn},序列{xn xn≠}是H的一个Besselian基且{xn xn≠}≥{xn},{xn xn≠}≥{xn≠}.结论 对于H的任一Schuder基{xn},定义U(xn xn≠):xn≠则{xn}是H的一个Besselian基当且仅当‖U‖<1.而且给出了彤eSZ基的5个等价刻画.  相似文献   

6.
非线性强增生算子方程解的迭代逼近定理   总被引:1,自引:1,他引:0       下载免费PDF全文
设1〈P≤2,X是实P-一致光滑的Banach空间,T:X→X是强增生算子.研究了用带误差的Ishikawa迭代程序:(xn+1)=(1-αn)xn+αn(f-Tyn+yn)+un, yn=(1-βn)xn+βn(f-Txn+xn)+υn,n≥0,)来逼近方程Tx=f解的问题,其中x0∈X,{un}{υn}是X中的有界序列,{αn},{βn},是[0,1]中的实数列.在无需假设条件αn→0之下,证明了,当T连续时,迭代序列{xn}强收敛到方程Tx=f的唯一解。  相似文献   

7.
设K是任意实Banach空间X中的闭凸子集,T ∶ K→K是Lipschitz严格伪压缩映象,在没有假设∑∞n=0αnβn<∞之下,本文证明了由xn+1=(1-αn) xn+αnTyn+un与yn=(1-βn) xn+βnTxn+vn,n∈N,生成的带误差的Ishikawa迭代序列强收敛到T的唯一不动点,并给出了更为一般的收敛率估计:若un=vn=0,n∈N,则有‖xn+1-x*‖≤(1-γn) ‖xn-x*‖≤…≤∏nj=0(1-γj) ‖x0-x*‖,其中{γn}是(0,1)中的序列,满足γn≥11+kmin(ε,η-ε) αn.所得结果改进和推广了最新的一些结果.  相似文献   

8.
研究序列{xn}的收敛性,其中x0∈C,yn=βnTxn (1-βn)xn,xn 1=anTyn (1-an)x,n=0,1,2,…这里0αn,βn≤1,C是Banach空间中的闭凸子集,T是从C到自身的映射。  相似文献   

9.
渐近非扩张映象的粘性逼近序列的强收敛定理   总被引:1,自引:0,他引:1  
假设E是具有一致Gateaux可微范数的实Banach空间,D是E的非空闭凸子集,f∶D→D是压缩映象,T∶D→D是渐近非扩张映象。设粘性逼近序列{xn}定义为xn 1=αnf(yn) (1-αn)Tnyn,yn=βnxn (1-βn)Tnxn(n≥0),其中αn∈[0,1],βn∈[0,1]。本文给出了{xn}强收敛于T的不动点的充要条件:若{αn}满足如下条件:limn→∞αn=0,∑∞n=0αn=∞,定义一簇压缩映象Sn∶D→D为Sn(z)=(1-dn)f(z) dnTnz,z∈D,其中dn=ktnn--αα,tn∈(α,1)(n=1,2,…),limn→∞tn=1且k2n-1≤(1-dn)2,n≥n0,设zn∈D是Sn的唯一不动点,即zn=Sn(zn)=(1-dn)f(zn) dnTnzn,n≥1,若limn→∞‖xn-Txn‖=0且{zn}强收敛于z*∈F(T),则{xn}强收敛于z*∈F(T)的充分必要条件是{yn}有界。本文的结果不仅是对Reich公开问题的解答,而且是对Reich[1-2]、Shioji和Takahashi[3]、张石生[4]相应结果的推广。  相似文献   

10.
文中讨论了下面修正Mann’s迭代格式{xn},x0∈K,xn 1=(1-αn)yn αnf(xn)yn=(1-βn)Txn βnxnn≥0的迭代序列的收敛性问题,在适当的假设条件之下在Banach空间中证明了迭代序列{xn}强收敛到非扩张映射的某个不动点x,且x是某个变分不等式在不动点集F(T)上的唯一解.结果改进和推广了Xu Hong-kun[1]、Kim Tae-hwa和Xu Hong-kun[2]等的相应结果.  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.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  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.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

19.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

20.
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