期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
植被光谱维特征提取模型 被引量:30
1
作者 谭倩 赵永超 +1 位作者 童庆禧 郑兰芬 《遥感信息》 CSCD 2001年第1期14-18,共5页
提出了一种针对植被的光谱维特征提取模型植被光谱特征提取模型 (Vegetation Spectral Feature ExtractionModel,缩写为 VSFEM)。该模型通过分析大量野外植被高光谱曲线 ,选择了 8个光谱维特征位置 。
关键词 植被 光谱维 高光谱 特征提取 生物物理参量估算 农业遥感 模型
下载PDF
面向Web服务系统的规划方法研究
2
作者 陈晓苏 张俊 +1 位作者 肖道举 刘辉宇 《华中科技大学学报(自然科学版)》 EI CAS CSCD 北大核心 2006年第3期8-10,共3页
将运筹学方法与计算机测试方法相结合,确定了为系统规划提供必要数据依据的方法.根据计算机系统的特点总结出计算机单元、服务、用户请求等三个典型估算参量,说明了各自的度量标准,并对为简化计算机模型而进行的约定进行了简要描述.参... 将运筹学方法与计算机测试方法相结合,确定了为系统规划提供必要数据依据的方法.根据计算机系统的特点总结出计算机单元、服务、用户请求等三个典型估算参量,说明了各自的度量标准,并对为简化计算机模型而进行的约定进行了简要描述.参照运筹学中目标规划的有关理论,利用估算参量建立了最优状态方程组与极限状态方程组,并给出了这两个方程组的一般解法.根据测试数据得到方程组的解,研究表明解在系统规划过程中对软、硬件投资估算、服务优化、系统升级、维护方案设计等方面有很好的参考作用. 展开更多
关键词 系统规划 估算参量 线性规划 数学模型
下载PDF
Yield Estimation Model of Citrus Based on Spectral Data and Agronomic Parameters 被引量:1
3
作者 邹扬庆 罗红霞 +3 位作者 Habtom Yemane Tekle 王俊 余天霞 张锐 《Agricultural Science & Technology》 CAS 2013年第10期1513-1516,共4页
With the development of precision agriculture, the research that applies Remote Sensing technology, especially hyperspectral remote sensing, to realize crop management, monitoring and yield estimation, has been concer... With the development of precision agriculture, the research that applies Remote Sensing technology, especially hyperspectral remote sensing, to realize crop management, monitoring and yield estimation, has been concerned. Nowadays, the growth-monitoring and yield-estimating methods in rice, wheat and other annual crops develop rapidly with some achievements having already been put into service. But the yield estimation research on perennial economic crops is few. Taking peren- nial citrus trees as the research object, using ASD spectrometer to collect citrus canopy spectral, this article studied and analyzed the citrus of veget&tion index and its relationship on yield, synthetically considered the influence of the agriculture pa- rameters on crop yield, and finally constructed the citrus yield estimation model based on the spectral data and agronomic parameters. Through the Significance Test and Samples' Test, olutained that the model's fitting degree was R=0.631, F= 13.201, P〈0.01 and the error rate of estimating accuracy was controlled in the range 3%-16%, proving that the model has statistical signification and reliability. It concluded that hyperspectral acquired from citrus canopy has substantial potential for citrus yield estimation. This study is an application and exploration of Hyperspectral Remote Sensing technology in the citrus yield estimation. 展开更多
关键词 CITRUS Yield estimation Hyperspectral data Agronomic parameter
下载PDF
软X射线Mo/Si多层膜反射率拟合分析 被引量:14
4
作者 王洪昌 王占山 +4 位作者 秦树基 李佛生 陈玲燕 朱杰 崔明启 《光学学报》 EI CAS CSCD 北大核心 2003年第11期1362-1365,共4页
由于多层膜的表界面粗糙度和材料之间的相互扩散等因素 ,导致多层膜的实际反射率小于理论计算的反射率 ,因此 ,多层膜结构参量的确定对镀膜工艺参量的标定具有重要意义。由于描述单个非理想粗糙界面散射的Stearns法适用于软X射线短波段... 由于多层膜的表界面粗糙度和材料之间的相互扩散等因素 ,导致多层膜的实际反射率小于理论计算的反射率 ,因此 ,多层膜结构参量的确定对镀膜工艺参量的标定具有重要意义。由于描述单个非理想粗糙界面散射的Stearns法适用于软X射线短波段区域 ,采用它的数学模型来描述软X射线多层膜的粗糙度 ,利用最小二乘法曲线拟合法对同步辐射测得的Mo/Si多层膜的反射率曲线进行拟合 ,得到了非常好的拟合结果 ,从而确定了多层膜结构参量 ,同时分析了多层膜周期厚度 ,厚度比率 ,界面宽度以及仪器光谱分辨率对多层膜反射特性的影响 ,这些工作都为镀膜工艺改进提供了一定的理论依据。 展开更多
关键词 薄膜光学 软X射线 界面缺陷 参量估算 反射率拟合 钼/硅多层膜 标量散射理论 界面散射 光谱分辨率
原文传递
Estimating biophysical parameters of rice with remote sensing data using support vector machines 被引量:13
5
作者 YANG XiaoHua HUANG JingFeng +4 位作者 WU YaoPing WANG JianWen WANG Pei WANG XiaoMing Alfredo R. HUETE 《Science China(Life Sciences)》 SCIE CAS 2011年第3期272-281,共10页
Hyperspectral reflectance (350-2500 nm) measurements were made over two experimental rice fields containing two cultivars treated with three levels of nitrogen application.Four different transformations of the reflect... Hyperspectral reflectance (350-2500 nm) measurements were made over two experimental rice fields containing two cultivars treated with three levels of nitrogen application.Four different transformations of the reflectance data were analyzed for their capability to predict rice biophysical parameters,comprising leaf area index (LAI;m-2 green leaf area m-2 soil) and green leaf chlorophyll density (GLCD;mg chlorophyll m 2 soil),using stepwise multiple regression (SMR) models and support vector machines (SVMs).Four transformations of the rice canopy data were made,comprising reflectances (R),first-order derivative reflectances (D1),second-order derivative reflectances (D2),and logarithm transformation of reflectances (LOG).The polynomial kernel (POLY) of the SVM using R was the best model to predict rice LAI,with a root mean square error (RMSE) of 1.0496 LAI units.The analysis of variance kernel of SVM using LOG was the best model to predict rice GLCD,with an RMSE of 523.0741 mg m-2.The SVM approach was not only superior to SMR models for predicting the rice biophysical parameters,but also provided a useful exploratory and predictive tool for analyzing different transformations of reflectance data. 展开更多
关键词 biophysical parameters support vector machines remote sensing
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部