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1.
针对目前公路工程土工试验数据处理方法的不足,利用数据拟合原理和计算机可视化编程技术,对公路边坡病害研究中的土工试验数据进行分析,给出了多项式线性最小二乘拟合和三次B样条函数拟舍两种方法及计算机实现算法。以含水量分布规律为例,对两种方法进行验证。结果表明,两种方法的拟合曲线均较好地逼近原始试验数据折线,三次B样条函数的偏差更小一些,平均绝对值误差比多项式线性最小二乘平均绝对值误差小0.0539%。  相似文献   

2.
在EV模型中,函数型EV多项式模型中未知参数估计问题已解决,但在结构型EV多项式模型中还未解决。利用改进的最小二乘估计方法构造了结构型EV多项式模型中未知参数β、2σ的估计量^β、^σ2,获得了估计量^β、^σ2分别是β、2σ的弱相合估计。  相似文献   

3.
讨论了矩阵最小多项式的几条性质,并利用线性相关的概念,给出了最小多项式的一种初等求法,该方法与其他方法^[3,4]相比更为简单,计算量更小。  相似文献   

4.
Pearson-χ2的最大距离的性质   总被引:9,自引:0,他引:9  
在Pearson—χ^2距离的基础上,对Pearson—χ^2距离进行了推广,给出了Pearson—χ^2最大距离的概念,既可克服Pearson—χ^2距离不具有列称性和惟一性的缺点,同时也能保持Pearson—χ^2距离的原有特性.讨论了其性质并与其他的距离进行了比较,最后给出了几类重要分布的Pearson—χ^2最大距离.  相似文献   

5.
Lagrange算子与Bernstein算子是用于处理多项式逼近问题的两个重要算子,这两种算子各有优缺点.为此,Sablonniere P.引入并研究了一种新的算子Bn^(k),它是一种介于Lagrange算子与Bernstein算子之间的拟插值算子.笔者研究了如何利用这种算子来完成满足某些给定条件的多项式曲线的设计.由于最适合应用的多项式是三次多项式,研究Bn^(k)(k=0,1,2,3)的性质,此时,算子B3^(0)、B3^(1)是Bernstein算子B3,B3^(3)是Lagrange算子L3,且B3^(2)f≠B3f,B3^(2)≠L3f,B3^(2),在体现逼近效果以及f的性质方面表现是最好的,且B3^(2)f型多项式曲线可以通过基变换方法得到新的控制点再由Bezier曲线作图法做出.  相似文献   

6.
目的研究部分线性自回归模型中误差矩的估计。方法利用非参数分段多项式估计和最小二乘法进行讨论。结果给出了误差tε的k(k≥1)阶矩及误差方差σ2的估计的大样本性质。结论误差k(k≥1)阶矩的估计的收敛速度为T-1/2,T(^σ2T-σ2)/D^T依分布收敛于N(0,1),其中^σ2T和D^2T分别为σ2和Var(23ε)的分段多项式估计,T为数据个数。  相似文献   

7.
对于单因素试验方差分析统计模型的假设检验问题,由χ^2分布和F分布导出了一个用来进行显著性检验的,检验定理,并作了定理的理论证明。  相似文献   

8.
通过对Weibull分布和Pearson-χ^2距离等概念的讨论,给出了2个Weibull分布的Pearson-χ^2距离和最大Pearson-χ^2距离的表达式。  相似文献   

9.
一类连通图族伴随多项式的最小根   总被引:4,自引:0,他引:4  
伴随多项式是色多项式的一种代数变形,它的引入主要是为了便于从补图的角度研究图的色惟一与色等价划分,其中寻找图的伴随多项式的最小根的序是主要方法之一.本文主要刻画了特征标为-2、基圈数为2的连通图族伴随多项式的最小根,给出了其对应的根极值图,并通过比较这些极图的最小根给出了此类连通图族伴瞎多项式最小根的序.  相似文献   

10.
Pearson—χ^2检验法是一种常见的齐一性检验法,但是所需要的样本量很大.在多个总体期望相等而方差单调的假设下,提出用F-检验法进行齐一性检验,所需样本量比Pearson—χ^2检验法大为减少.通过Monte—Carlo模拟还可以看到,在节省样本的同时,F-检验法还具有比Pearson—χ^2检验法更高的功效.  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.
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   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
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   

15.
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   

16.
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   

17.
18.
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   

19.
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   

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   

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