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1.
现有的区间组合预测模型往往是将单项预测方法不同时刻的预测精度转化为实数,这将导致预测信息的损失。因此,文章提出一种新的区间预测精度的概念,将单项预测方法不同时刻的精度用区间数表示,并利用可能度对其进行排序;将排序后的预测精度作为诱导变量,构建基于区间预测精度和诱导有序加权平均(induced ordered weighted averaging,IOWA)算子的区间变权组合预测模型;实例分析说明了该区间组合预测方法的有效性;最后,对模型参数做了灵敏度分析。  相似文献   

2.
4种诱导有序加权平均模型的构建   总被引:1,自引:1,他引:0  
诱导有序加权平均算子是一种新的信息集结算子,用途非常广泛.基于诱导有序加权平均算子构建了4种组合预测模型.实例表明这种模型能有效地提高预测精度.  相似文献   

3.
客观世界中人们会用区间数来描述不确定和不完备的信息,由此开展区间型的组合预测方法的研究很有意义.将区间数的左、右端点分别视作时间序列,以向量夹角余弦为准则,结合IOWHA信息集结算子,借鉴实数型组合预测的思想,将实际值区间数和变权系数组合预测值区间数的左、右端点序列分别建立最优组合预测模型,最后引入偏好系数转换成单目标最优组合预测模型而实现求解.  相似文献   

4.
在连续区间有序加权调和平均(Continuous ordered weighted harmonic averaging,C-OWHA)算子的基础之上,提出连续区间广义有序加权调和平均(Continuous generalized ordered weighted harmonic averaging,C-GOWHA)算子。对该算子进行拓展,提出了加权的连续区间广义有序加权调和平均算子、有序加权的连续区间广义有序加权调和平均算子、诱导有序加权的连续区间广义有序加权调和平均算子及组合的连续区间广义有序加权调和平均算子,以便能够用于计算区间数据组。此外,在诱导有序加权的连续区间广义有序加权调和平均算子的基础之上,以灰色趋势关联度为相关性指标,提出了基于灰色趋势关联度的诱导有序加权的连续区间广义有序加权调和平均算子的区间数组合预测模型,通过实例分析,表明该模型能够起到提高预测精度的作用。  相似文献   

5.
针对预测值为区间数形式,将区间数距离和诱导连续有序加权平均算子ICOWA结合,以ICOWA算子下实际预测序列与组合预测序列的距离最小为准则,构建了变权组合预测模型,并证明了模型的非劣性.最后,通过实例说明了模型能够有效提高预测精度.  相似文献   

6.
针对实际值序列和预测值序列均为区间数的组合预测问题,把区间数的左右端点作为两个独立的时序数列,通过引入诱导有序加权调和平均(IOWHA)算子,分别建立以区间数左右端点的倒数离差相关系数最大化为准则的IOWHA算子的变权系数最优组合预测模型,再通过引入偏好系数把多目标最优化模型转化为单目标最优化模型,并尝试给出各模型最优解的性质.最后利用数据进行分析,并和其他单项预测方法或组合预测方法相比较,从而证明该方法确实能够提高区间预测的精度.  相似文献   

7.
在广义诱导有序加权对数平均算子(IGOWLA算子)的基础上,引入指数支撑度以及构建了一种基于支撑度的IGOWLA算子的最优组合预测模型,并对该模型的预测精度、优性及非劣性给出定义.实例分析表明,该组合预测模型优于传统的组合预测模型,能够充分利用各个单项预测方法的信息并能提高预测精度,是一种优性组合预测.  相似文献   

8.
针对C-OWGA(continuous ordered weighted geometric averaging)算子只能集结单一区间数据的不足,提出一类连续区间数集结新算子.在C-OWGA基础上引入IGOWA(induced generalized ordered weighted averaging)算子,构造出诱导广义加权的C-OWGA(induced generalized ordered weighted continuous ordered weighted geometric averaging,即IGOWC-OWGA)算子,以向量夹角余弦为相关性准则,构建一个连续区间组合预测新模型.最后经实例验证表明该新方法在提高预测精度方面具有显著效果.  相似文献   

9.
基于IOWA算子的赤潮LMBP神经网络组合预测模型   总被引:1,自引:0,他引:1  
针对现有赤潮单项预测模型不能综合各种理化因子有效信息的问题,提出了一种赤潮组合预测模型,该模型基于诱导有序加权平均(IOWA)算子与Levenberg-Marquardt人工神经网络(LMBP)算法,能够有效集结各种理化因子的信息,其预测精度比单项LMBP神经网络预测模型有较大提高.采用烟台四十里湾赤潮监测数据对该模型进行实验.结果验证了该模型的有效性和实用性.  相似文献   

10.
为了克服传统的单项预测方法选取固定参数时的不足,在诱导有序加权调和平均算子(IOWHA算子)的基础上引入Theil不等系数,构建了基于Theil不等系数的IOWHA算子的最优组合预测模型.对该模型的预测精度、优性及非劣性进行定义,从理论角度探究了其非劣性组合预测、优性组合预测存在的充分条件.实例分析表明,该组合预测模型优于传统的组合预测模型,能够充分利用各个单项预测方法的信息并能提高预测精度,是一种优性组合预测.  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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