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.
容错性对于互联网络来说极为重要,这是因为网络规模的扩大会导致一些元器件的脆弱性.为维持多处理机系统的高可靠性能有必要将故障处理机识别和替换下来,这一过程通常称为故障诊断分析.通过对扭立方连接网络TN n的容错性分析,确定了其在PMC诊断模型下的条件诊断度,并给出简易的t/t-诊断算法.  相似文献   

2.
利用变分原理和Z2不变群指标对一类二阶时滞微分方程(a(t)x′(t-τ))′-b(t)x(t-)τ+fλ(t,x(t),x(t-)τ,x(t-2)τ)=0的周期解问题进行研究,得出在一些条件下方程有2n个周期为2π的非平凡周期解。  相似文献   

3.
研究一类一阶非线性时滞微分方程,x′(t)+a(r)f(x(t))+p(t)g(x(t))h(x(t-τ1(t)),x(t-τ2(t)),…,x(t-τn(t)))=0,其中,a,p,τj∈C(R^+,R^+),limt→+∞(t-τ1(t))=+∞,j=1,2,…,n,f,g∈C(R,R),获得了其存在正解的充分条件。  相似文献   

4.
n个滞量的微分差分方程周期解的存在性   总被引:1,自引:0,他引:1       下载免费PDF全文
通过构造多元函数,定性分析一个耦合自治常微分方程组周期解的存在性,研究含多个滞量的微分差分方程x′(t)=F(x(t),x(t-τ1),x(t-τ2),...,x(t-τn))和x′(t)=F(x(t),x(t-τ),x(t-2τ),…,x(t-nτ))周期解的存在性问题,获得系统存在非平凡振动周期解的一组充分条件,推广和改进了文献[3~5]的结果.  相似文献   

5.
为提高系统故障诊断的诊断度,Somani 和Peleg提出了t/k诊断故障策略. n维折叠超立方体网络是具有2n个顶点,(n+1)2n-1条边的(n+1)-维正则图,它是n维超立方体网络增加2n-1补边得到的.中证明了当n≥6和1≤k≤n+1时n维超立方体网络是t/k可诊断的,其中t=(k+1)(n+1)-1/2(k+1)(k+2)+1.  相似文献   

6.
邓伟 《科技信息》2009,(7):166-167
研究带有时滞的Duffiang型方程ax″(t)+bx'(t)+cx(t)+g(t-τ1,x'(t-τ2),x″(t-τ3))=p(t)=p(t+2τ)利用Brouwer度等理研究了上述方程2τ周期的存在条件.  相似文献   

7.
复杂多体系统通常可以看作是一个系统和热浴相互耦合作用构成的体系.从郎之万方程的推导出发,可以得出线性耦合情况下热浴的关联函数为〈F(t)·F(τ)〉=kT∑j((λj^2)/(mjωj~2))cosωj(t-τ).线性耦合情况下系统的郎之万方程为P(t)+(δHS(m)/δQ)+λ^2 integral from n=0 to t(dτK(t-τ)·P(τ)=λF(t))  相似文献   

8.
一类高阶微分方程周期解的存在性   总被引:1,自引:1,他引:0  
考虑一类高阶微分方程ax^(2n)(t)+cx’(t)+bx(t)+g[x(t-τ)]=p(t),利用重合度理论,获得了此类方程至少存在一个T-周期解的充分条件。  相似文献   

9.
利用Banach压缩映象原理,研究下列一阶非线性中立型时滞微分方程d/(dt)[x(t)]+c(t)x(t-τ1)+d(t)x(t-τ2)]+h(t)f(t,x(t-σ1(t)),x(t-σ2(t)),…,x(t-σk(t)))=g(t)的非振动解的存在性,并获得了相应非振动解的迭代逼近序列.  相似文献   

10.
利用变分原理和Zz不变群指标,研究一类二阶中立型泛函微分方程(p(t)(μx'(t)+x'(t-τ)+μx'(t-2τ)))’-q(t)x(t-τ)+λf(t,x(t)),x(t-τ),x(t-2τ))=0,|μ|〈1/2多重周期解的存在性问题,得出了有关新结果.  相似文献   

11.
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   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
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   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
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   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  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