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1.
区域粮食生产灰色关联分析   总被引:2,自引:0,他引:2  
采用灰色系统理论,对影响河南省粮食产量的诸因素进行动态灰色关联分析,运用GM(1,1)模型在对其发展趋势预测的基础上,进行趋势关联分析.研究结果动态地反映了河南粮食生产发展的趋势,为粮食生产持续发展、科学决策提供理论依据.  相似文献   

2.
安徽省粮食生产时空变化特征的影响因素分析   总被引:3,自引:0,他引:3  
根据1997-2007年安徽省统计资料,对全省粮食生产时空变化特征进行了分析,在此基础上,进一步对影响安徽省粮食生产的诸要素进行了灰色关联分析.结果表明:粮食播种面积(耕地面积、粮食播面比与复种指数三者的乘积)、单产、农田水利设施以及农民的粮食收入是影响安徽省粮食生产时空变化的相对活跃因素,粮食生产支持政策对全省粮食生产起到了积极作用,城镇化、工业化以及农业现代化对粮食生产的影响相对较小,但随着工业化、城镇化的进一步发展所带来的耕地非农化、粮食总需求增长的压力,势必对粮食生产提出更高的要求.粮食生产时空变化是资源禀赋背景下,城镇化、工业化及政策因素引致农户响应的结果.  相似文献   

3.
粮食生产影响因素的灰色关联动态分析   总被引:14,自引:0,他引:14  
根据1949~2001年济宁市(不包括泗水、汶上、梁山)各县(市、区)的统计资料,分析了53年来粮食生产的发展变化历程,并进一步以1978~2001年济宁市12个县(市、区)的统计资料为基础,运用灰色系统理论,对影响济宁市粮食生产的诸因素进行关联动态分析,从定量的角度考察了粮食产量与诸因子的关联程度,指出了粮食单产、劳动力、有效灌溉面积、耕地面积和播种面积是影响济宁市粮食生产的最主要因素,并提出粮食生产可持续发展的基本对策,为解决济宁市粮食产量持续稳定增长提供了理论依据。  相似文献   

4.
宿州市粮食生产灰色关联分析及预测   总被引:1,自引:0,他引:1  
根据宿州市1978~2009年粮食产量相关统计资料,运用灰色模型对宿州市粮食生产预测并进行影响因素灰色关联分析.结果表明:宿州市粮食产量整体呈上升趋势,但中间因气候因素导致较大波动,若措施得当,未来6年粮食产量将逐年增加;9个影响因子中,粮食单产、粮食播种面积、农业生产资料价格及农田水利设施是影响宿州市粮食生产的最重要的因子.  相似文献   

5.
基于灰色关联支持向量机的中国粮食产量预测模型   总被引:2,自引:0,他引:2  
研究我国粮食生产系统的变动规律,做好粮食产量科学预测不仅是制定农业政策的重要依据,而且对于保证我国的粮食安全具有重要意义。鉴于粮食生产系统的复杂性和信息不完全性,在对粮食生产系统灰色关联分析的基础上,确定出影响粮食产量的主要因子,然后根据支持向量机回归原理,建立了基于灰色关联支持向量机的预测模型。预测结果表明该模型具有较高的预测精度,为粮食产量预测提供了一条新的途径。  相似文献   

6.
基于灰色关联支持向量机的中国粮食产量预测模型   总被引:1,自引:0,他引:1  
研究我国粮食生产系统的变动规律,做好粮食产量科学预测不仅是制定农业政策的重要依据,而且对于保证我国的粮食安全具有重要意义。鉴于粮食生产系统的复杂性和信息不完全性,在对粮食生产系统灰色关联分析的基础上,确定出影响粮食产量的主要因子,然后根据支持向量机回归原理,建立了基于灰色关联支持向量机的预测模型。预测结果表明该模型具有较高的预测精度,为粮食产量预测提供了一条新的途径。  相似文献   

7.
灰色综合关联度及其应用   总被引:5,自引:0,他引:5  
在讨论灰色系统理论中的灰色关联度的同时,定义了灰色综合关联度,并对内蒙古自治区科右中旗粮食生产结构进行了关联排序和分析,认为定义的灰色综合关联度较好地刻划了该旗粮食生产发展的基本结构和现状  相似文献   

8.
运用灰色关联理论,对影响内蒙古自治区粮食产量的因素进行灰色关联分析,并提出了相应的发展对策。关联分析表明,播种面积与粮食产量的关联度最大,其次为粮食单产和农业劳动力。  相似文献   

9.
中国粮食多因子灰色关联神经网络预测研究   总被引:11,自引:0,他引:11  
针对BP神经网络多变量输入难以确定的缺点,提出了采用灰色关联分析法确定主要影响因子输入的多因子灰色关联分析神经网络预测模型,并给出了灰色关联神经网络BP预测模型的建立方法,对我国粮食生产影响因子多因子预测实证研究结果表明,用该网络建立的模型经过训练后,可得到影响粮食产出的主要影响因子及其之间的非线性关系,网络模型新颖,具有较好的预测精度及较好的预测效果,可广泛应用于各种预测研究,有较高的推广价值。  相似文献   

10.
本文把黑龙江垦区经济作为研究对象,分析了以黑龙江垦区生产活动为核心的区域经济圈的特点,进一步剖析东北亚经济区域的特殊性,并对如何使黑龙江垦区经济更好地融入东北亚经济圈进行了分析。为进一步加快建设垦区现代化大农业,以创新理论指导垦区现代化大农业的建设,为城乡一体经济跨越的实现提供理论依据。  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.
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   

20.
Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.  相似文献   

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