改进的最优非负变权组合模型及其应用     

吴少华  程朋根  付博 《大地测量与地球动力学》2016,36(11):968-971

根据GM(1,1) 、BP神经网络、卡尔曼滤波的特点,建立以灰色关联度最大为准则的最优非负变权组合预测模型,在一定程度上抑制了误差“放大”的效应。与以误差平方和最小为准则的变权组合模型、各最优加权组合模型、各单一模型进行对比分析,结果表明,本文模型预测精度最高。  相似文献   

旅游地社区参与度熵权层次分析评价模型与应用   总被引：4，自引：1，他引：3  

侯国林  黄震方 《地理研究》2010,29(10):1802-1813

建立旅游地社区参与度熵权层次分析评价模型,以周庄、同里、西递、宏村为研究对象,对我国传统村镇旅游地社区参与度进行定量评价。研究表明:(1)旅游规划与决策参与度是影响传统村镇旅游地社区总体参与度的关键性因素;(2)西递处于社区高度参与状态,周庄、同里、宏村处于社区中度参与状态,四个旅游地社区参与度由大到小的顺序为:西递＞周庄＞同里＞宏村;(3)我国传统村镇旅游地居民参与旅游规划与决策的程度偏低,成为影响社区参与度总体得分和社区参与层次的主要原因;(4)导致社区参与度差异的主要因素为传统村镇旅游地在景区经营管理模式、旅游地社会经济发展阶段、社区旅游制度和政策、社区形态与旅游资源属性上存在差异。  相似文献   

210Pb in a tropical coastal lagoon sediment core     

F. Páez-Osuna  Enrique F. Mandelli 《Estuarine, Coastal and Shelf Science》1985,20(3):367-374

Excess ²¹⁰Pb in a core from a Mexican Coastal Lagoon, which has no connection with the sea shows a small but measurable decay over the length of the core, when different approaches were compared (excess and corrected ²¹⁰Pb activity with depth, total and inorganic cumulative weights) significant differences in the values for the sedimentation rate are obtained. The best coefficient correlation was calculated when corrected ²¹⁰Pb activity for the uneven distribution of organic matter and cumulative inorganic weight is considered ($\text{ω}\text{= 0·93 cm yr}{}^{\mathrm{?1}}$, R = ?0·86; ω = 0·51 cm yr^?1 for the top 13 cm, R = ?0·90 and 1·52 cm yr^?1 for the interval 14–46 with R = ?0·96).Time frames in the sedimentary column were in agreement between the ²¹⁰Pb calculated time and the appearance of shells fragments probably associated with the disturbances caused by the 1961 hurricane Tara.The surface accumulation rate is equivalent to a mean deposition of 262·5 g m^?2 yr^?1 or organic matter which is minor but comparable to some salt marshes of United States.  相似文献   

Error sources of precipitation measurements using electronic weight systems   总被引：1，自引：0，他引：1  

B. Sevruk  B. Chvíla   《Atmospheric Research》2005,77(1-4):39

Liquid precipitation amounts below 0.05 mm in combination with intervals of measurement greater than 3 min and temperature above 15 °C can considerably affect the measured precipitation using electronic weighing gauges. This was shown by tests using different weights put in the gauge in different intervals in order to simulate different precipitation amounts and measuring intervals. These results were confirmed by field intercomparison measurements using pit gauges in two locations in Slovakia. In total, 1571 weight tests consisting of combinations of simulated precipitation amounts of 0.025, 0.05, 0.2 mm and measuring intervals of 1, 2, 3, 5 and 10 min were carried out. Based on these tests and special software, a new gauge was developed. Using this gauge, the abovementioned error sources were minimized. The Slovak Hydrometeorological Institute now uses it at 90 gauge sites. This type of gauge was selected to participate in the current World Meteorological Organization, WMO, Intercomparison measurements of recording precipitation gauges.  相似文献   

基于双正交多小波的SAR与可见光图像融合研究   总被引：1，自引：3，他引：1  

洪日昌  吴秀清  杨浩 《测绘信息与工程》2006,31(2):1-3

针对已有的数据融合技术,提出了一种基于双正交多小波变换的遥感图像融合算法,采用了邻域方差准则和非线性加权相结合的方法,分别融合小波低频和高频系数,试验选取星载SAR与SPOT可见光图像进行融合,实现了很好的融合效果。  相似文献   

单位权方差公式的统一推证     

郭宗河  郑进凤 《测绘科学与工程》2006,26(1):29-31,40

本文从二次型的期望公式出发，推导了经典最小二乘平差、最小二乘滤波、最小二乘推估和最小二乘配置的验后单位权方差的估计公式。  相似文献   

The Application of Artificial Neural Networks to Landslide Susceptibility Mapping at Janghung, Korea   总被引：13，自引：0，他引：13  

Saro Lee  Joo-Hyung Ryu  Moung-Jin Lee  Joong-Sun Won 《Mathematical Geology》2006,38(2):199-220

The purpose of this study was to develop techniques for landslide susceptibility using artificial neural networks and then to apply these to the selected study area at Janghung in Korea. Landslide locations were identified from interpretation of satellite images and field survey data, and a spatial database of the topography, soil, forest, and land use. Thirteen landslide-related factors were extracted from the spatial database. These factors were then used with an artificial neural network to analyze landslide susceptibility. Each factor's weight was determined by the back-propagation training method. Five different training sets were applied to analyze and verify the effect of training. Then the landslide susceptibility indices were calculated using the back-propagation weights, and susceptibility maps were constructed from Geographic Information System (GIS) data for the five cases. Landslide locations were used to verify results of the landslide susceptibility maps and to compare them. The artificial neural network proved to be an effective tool for analyzing landslide susceptibility.  相似文献   

堤防工程安全评估专家赋权模型   总被引：4，自引：0，他引：4  

顾冲时  汪自力  刘成栋 《岩土力学》2006,27(12):2099-2104

针对堤防工程安全影响因素多，影响因素既有定量又有非定量指标，并且存在指标的模糊性和不确定性等特点的问题；利用模糊数学和模式识别理论以及动态聚类方法等，提出了堤防工程安全评估专家主观和客观赋权模型：在此基础上，还提出了融合专家主观和客观权重的堤防工程安全评估专家综合赋权模型。并用实例对所提出的模型进行了验证。  相似文献   

南海北部灾害地质稳定度评价模型     

杨春霞  王春民  王圣洁 《中国地质灾害与防治学报》2006,17(1):77-79

海洋经济的开发需要了解海洋灾害地质环境状况。海洋工程设计与建设需要考虑海底工程地质条件,特别是国家宏观决策更需要了解海洋地质环境的基本特征以及灾害地质类型、分布规律。灾害地质综合评价可以基于灾害地质分区进行,灾害地质综合评价的目标是比较不同分区的灾害地质稳定性并给出定量评价。文中就南海北部灾害地质稳定性提出了网格化加权统计模型。该模型结合专家智能的参与,体现了不同种类灾害地质因素的等级差别。另外还考虑到不同种类灾害地质因素之间的空间分布差异性及同类灾害地质因素的空间分布差异性。根据模型计算结果将评价区划分为稳定区、过渡区及危险区。这种划分通过与南海北部灾害地质稳定性定性描述对比。证明该模型在全面地定量化反映南海北部的地质环境状况方面是实用的。由于模型建立过程中各灾害因素权重分值的设定完全依赖于专家智能,因此,今后应当致力于更精确地确定权重分值。  相似文献   

潼关金矿区矿渣型泥石流熵权评价   总被引：3，自引：0，他引：3  

徐友宁  陈社斌  袁汉春  张江华  刘瑞平  何芳 《地质科技情报》2006,25(5):101-104

在简述信息熵概念的基础上,对陕西潼关金矿区8条泥石流沟堆积的采矿废石量、沟谷纵坡降比等9个定量、定性调查指标进行了统计,求出各指标熵Hj、熵权Wj以及沟谷指标可能的概率值fij后,计算得出了潼关金矿区矿渣型泥石流潜势度信息熵的综合评价值;探讨了熵权评价与主观赋权评价的结果差异的原因及建议.  相似文献