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.
两种加权观测融合算法的全局最优性和完全功能等价性   总被引:8,自引:5,他引:8  
对于基于Kalman滤波的多传感器观测数据融合,有两种加权观测融合算法。应用Kalman滤波器,证明了同集中式观测融合算法相比,它们具有全局最优性和完全功能等价性。它们不仅可给出全局最优Kalman估值器(滤波器、预报器和平滑器)、白噪声估值器和信号估值器,而且可明显减少计算负担,便于实时应用。  相似文献   

2.
对于带不同局部动态模型的多传感器线性离散时变随机控制系统,应用Kalman滤波方法,在按标量加权最优融合准则下,提出了统一和通用的最优信息融合白噪声反卷积估值器,并对定常系统提出了稳态最优信息融合白噪声反卷积估值器。它们可统一处理白噪声反卷积融合滤波、平滑和预报问题。为了计算最优加权,提出了输人白噪声局部估计误差互协方差计算公式。它们在石油、地震勘探领域中有重要的应用背景。  相似文献   

3.
基于 Kalman 滤波,对带非零均值的相关噪声系统提出了统一的稳态白噪声估值器,可统一处理白噪声滤波、平滑和预报问题。它们包括稳态输入白噪声估值器和观测白噪声估值器,且包括白噪声新息滤波器和 Wiener 滤波器。一个 Bernoulli-Gaussian 白噪声的仿真例子说明了它们的有效性。  相似文献   

4.
白噪声反卷积问题在石油地震勘探中具有重要的应用背景。利用Kalman滤波方法提出了多传感器最优观测加权融合白噪声反卷积Wiener滤波器。同集中式和分布式融合方法相比,不仅可得到全局最优白噪声融合估值器,而且可显著地减小计算负担,便于实时应用。一个四传感器Bernoulli-Gaussian白噪声加权观测融合估值器的仿真例子说明了其有效性。  相似文献   

5.
多传感器分布式协方差信息融合Kalman滤波理论   总被引:3,自引:3,他引:3  
对于带多传感器和带相关噪声的线性离散时变随机控制系统,基于按矩阵加权、按对角阵加权和按标量加权的三种最优信息融合规则,提出了相应的三种分布式最优信息融合Kalman估值器,可统一处理融合滤波、预报和平滑问题。为了计算最优加权,提出了计算局部估计误差协方差公式。作为特殊情形,还提出了定常系统的稳态最优信息融合Kalman估值器,其中用解Lyapunov方程计算局部估计误差协方差。同集中融合Kalman估值器相比,可减小计算负担。同单传感器Kalman估值器相比,可提高精度。它们构成了统一和通用的分布式协方差信息融合Kalman滤波理论。  相似文献   

6.
通过对观测方程的线性变化,将带有色观测噪声系统化为带白色观测噪声的系统。基于自回归滑动平均(ARMA)新息模型,由稳态最优Kalman估值器导出了渐近稳定的Wiener状态估值器,可统一处理滤波、平滑和预报问题。一个仿真例子说明它们的有效性。  相似文献   

7.
对于带多传感器的Y-可观广义线性离散随机系统,通过状态线性变换,将其化为两个降阶的非广义多传感器子系统。应用Kalman滤波方法和白噪声估值器,提出了子系统和原系统的局部状态估值器及它们的误差互协方差公式。在线性最小方差按矩阵加权,按对角阵加权和按标量加权最优信息融合准则下,提出了原系统状态的三种稳态广义Kalman。融合器,可统一处理融合滤波、平滑和预报问题,且可改善局部估计精度。  相似文献   

8.
基于Kalman滤波的白噪声估计理论的推广   总被引:2,自引:0,他引:2  
应用Kalman滤波方法和射影理论,将现行的白噪声估计理论推广到一般的随机系统,其中系统噪声在相邻时刻是相关的,且系统噪声和观测噪声在相同和相邻时刻也是相关的。提出了统一的最优和稳态白噪声和拟白噪声估值器。一个仿真例子说明了其有效性。  相似文献   

9.
对于带相关观测噪声和带不同观测阵的多传感器线性离散定常随机系统,用加权最小二乘(WLS)法提出了两种加权观测融合稳态Kalman滤波方法,可处理状态、白噪声和信号融合估计。基于稳态信息滤波器证明了它们功能等价于集中式融合稳态Kalman滤波方法,因而具有渐近全局最优性,且可显著减少计算负担。两个跟踪系统数值仿真例子验证了它们的功能等价性。  相似文献   

10.
对于带相关的输入白噪声和观测白噪声及相关观测白噪声的多传感器线性离散定常随机系统,用加权最小二乘(wLs)法提出了一种加权观测融合稳态Kalman滤波算法,并基于信息滤波器证明了它同集中式观测融合稳态Kalman滤波算法功能的等价性.因而,它具有渐近全局最优性,且可减少计算负担.一个跟踪系统数值仿真例子验证了它的功能等价性.  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   

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