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遥感技术已成为空间信息与数字技术专业领域内的热门研究方向,基于遥感技术的城市问题研究受到广泛关注,本文主要探讨了空间信息与数字技术专业内开设《城市遥感》课程的必要性及建设方案,主要强调理论教学与实践训练相结合的培养模式。 相似文献
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YANG Xiao-hua HUANG Jing-feng WANG Jian-wen WANG Xiu-zhen LIU Zhan-yu 《浙江大学学报(A卷英文版)》2007,8(6):883-895
Hyperspectral reflectance (350~2500 nm) data were recorded at two different sites of rice in two experiment fields including two cultivars, and three levels of nitrogen (N) application. Twenty-five Vegetation Indices (VIs) were used to predict the rice agronomic parameters including Leaf Area Index (LAI, m2 green leaf/m2 soil) and Green Leaf Chlorophyll Density (GLCD, mg chlorophyll/m2 soil) by the traditional regression models and Radial Basis Function Neural Network (RBF). RBF emerged as a variant of Artificial Neural Networks (ANNs) in the late 1980’s. A large variety of training algorithms has been tested for training RBF networks. In this study, Original RBF (ORBF), Gradient Descent RBF (GDRBF), and Generalized Regression Neural Network (GRNN) were employed. Results showed that green waveband Normalized Difference Vegetation Index (NDVIgreen) and TCARI/OSAVI have the best prediction power for LAI by exponent model and ORBF respectively, and that TCARI/OSAVI has the best prediction power for GLCD by exponent model and GDRBF. The best performances of RBF are compared with the traditional models, showing that the relationship between VIs and agronomic variables are further improved when RBF is used. Compared with the best traditional models, ORBF using TCARI/OSAVI improves the prediction power for LAI by lowering the Root Mean Square Error (RMSE) for 0.1119, and GDRBF using TCARI/OSAVI improves the prediction power for GLCD by lowering the RMSE for 26.7853. It is concluded that RBF provides a useful exploratory and predictive tool when applied to the sensitive VIs. 相似文献
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郭朝霞 《武汉工程职业技术学院学报》2005,17(3):77-79
本文说明了项目教学法的概念;并结合作者的教学实践,以项目为中心对土管专业的遥感课程教学进行了详细的教学设计;最后为项目教学法能更有效的实施提出了建议。 相似文献
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以承德市的森林分布区为研究区域,基于改进的光能利用率模型,利用2008年MODIS/NDVI产品和地面气象站点数据,结合土地覆被类型,估算承德市森林植被的年净初级生产力,并分析其时空分布格局.研究结果表明:2008年承德市森林NPP的总量为1.075×108 g.a-1,年平均值为424.59 g.m-2.a-1,NPP最高值为656.78 g.m-2.a-1.总体空间分布趋势是东南高,西北低,其季节变化较明显,呈单峰型. 相似文献
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Remote sensing techniques have the potential to provide information on agricultural crops quantitatively, instantaneously and above all nondestructively over large areas. Crop simulation models describe the relationship between physiological processes in plants and environmental growing conditions. The integration between remote sensing data and crop growth simulation model is an important trend for yield estimation and prediction, since remote sensing can provide information on the actual status of the agricultural crop. In this study, a new model (Rice-SRS) was developed based mainly on ORYZA1 model and modified to accept remote sensing data as input from different sources. The model can accept three kinds of NDVI data: NOAA AVHRR(LAC)-NDVI, NOAA AVHRR(GAC)-NDVI and radiometric measurements-NDVI. The integration between NOAA AVHRR (LAC) data and simulation model as applied to Rice-SRS resulted in accurate estimates for rice yield in the Shaoxing area, reduced the estimating error to 1.027%, 0.794% and (−0.787%) for early, single, and late season respectively. Utilizing NDVI data derived from NOAA AVHRR (GAC) as input in Rice-SRS can yield good estimation for rice yield with the average error (−7.43%). Testing the new model for radiometric measurements showed that the average estimation error for 10 varieties under early rice conditions was less than 1%. Project supported by the National Defense Scientific and Technological Committee of China(No. Y97#14-6-2) 相似文献
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Mapping paddy rice with multi-date moderate-resolution imaging spectroradiometer (MODIS) data in China 总被引:1,自引:0,他引:1
Hua-sheng SUN Jing-feng HUANG Alfredo R. HUETE Dai-liang PENG Feng ZHANG 《浙江大学学报(A卷英文版)》2009,10(10):1509-1522
The objective of this study was to obtain spatial distribution maps of paddy rice fields using multi-date moderateresolution imaging spectroradiometer (MODIS) data in China. Paddy rice fields were extracted by identifying the unique characteristic of high soil moisture in the flooding and transplanting period with improved algorithms based on rice growth calendar regionalization. The characteristic could be reflected by the enhanced vegetation index (EVI) and the land surface water index (LSWI) derived from MODIS sensor data. Algorithms for single, early, and late rice identification were obtained from selected typical test sites. The algorithms could not only separate early rice and late rice planted in the same fields, but also reduce the uncertainties. The areal accuracy of the MODIS-derived results was validated by comparison with agricultural statistics, and the spatial matching was examined by ETM+ (enhanced thematic mapper plus) images in a test region. Major factors that might cause errors, such as the coarse spatial resolution and noises in the MODIS data, were discussed. Although not suitable for monitoring the inter-annual variations due to some inevitable factors, the MODIS-derived results were useful for obtaining spatial distribution maps of paddy rice on a large scale, and they might provide reference for further studies. 相似文献
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ERP系统总体规划是成功实施该项目的先决条件,对整个实施过程有着重要的指导意义,对资金、人才相对薄弱的中小型模具企业更是如此.文章应用工业工程(IE)、业务流程重组(BPR)以及计算机集成制造系统(CIMS)等先进的管理哲学、理念和技术,从模具行业现状、企业现状、以及ERP系统的特点、性能等方面做了较为详尽的阐述,提出了中小模具企业ERP系统总体规划中常见且易忽视的六大关键问题. 相似文献
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Chuan ZUO Xi-sheng XIE Hong-yu QIU Yao DENG Da ZHU Jun-ming FAN 《Journal of Zhejiang University. Science. B》2009,10(5)
Astragalus mongholicus (AM) derived from the dry root of Astragalus membranaceus Bge. var. mongolicus (Bge.) Hsiao is a widely used traditional Chinese medicine. The present study investigated the potential role of AM on renal fibrosis on a rat model of unilateral ureteral obstruction (UUO). We divided 48 Sprague-Dawley rats randomly into 4 groups: sham-operated group (Sham), untreated UUO group, AM-treated (10 g/(kg.d)) UUO group, and losartan-treated (20 mg/(kg.d)) UUO group as positive control. Haematoxylin & eosin (HE) and Masson staining were used to study the dynamic histological changes of the kidneys 7 and 14 d after operation. The expressions of fibronectin (FN), type I collagen (coII), hepatocyte growth factor (HGF), transforming growth factor-pi (TGF-βl), and a-smooth muscle actin (a-SMA) were analyzed by real-time polymerase chain reaction (PCR), immunohistochemistry staining, and Western blot. Results show that, similar to losartan, AM alleviated the renal damage and decreased the deposition of FN and colI from UUO by reducing the expressions of TGF-pi and a-SMA (P<0.05), whereas HGF increased greatly with AM treatment (P<0.05). Our findings reveal that AM could retard the progression of renal fibrosis. The renoprotective effect of AM might be related to inhibition of myofibroblast activation, inducing of HGF and reducing of TGF-β1 expression. 相似文献
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全球卫星导航定位系统(GNSS)气象学是南京信息工程大学依托\"大气科学\"一流学科,充分发挥大气探测和大地测量方面的技术储备和人才优势,面向测绘类专业开设的气象特色课程.该课程的开设对于推动GNSS大气遥感技术人才培养,支撑气象观测技术自动化、信息化和智能化发展具有重大意义.课程团队从课程培养目标、课程建设、课程组织、成... 相似文献
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The main purpose of this paper is to demonstrate how to apply the Hierarchical Linear Modeling (HLM) technique to multi-wave Curriculum-Based Measurement (CBM) measures in modeling academic growth and assessing its relations to student- and instruction-related variables. HLM has advantages over other statistical methods (e.g., repeated measures ANOVA, Structural Equation Modeling) in modeling academic growth. The advantages include allowing more flexible research designs in collecting multiple data points and estimating growth rates and their relations to correlates in more reliable, accurate ways. CBM, as a multi-wave progressmonitoring system, also has distinctive psychometric features that facilitate longitudinal research on academic skill development. These features include provision of multiple data points within short time periods, good validity and reliability, and sensitivity for detecting small degrees of change. Finally, research questions related to assessing the academic growth of students with learning difficulties and using assessment results to improve educational practices for them are discussed 相似文献
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Yijia MAO Lingkai MENG Huayi LIU Yuting LU Kuo YANG Guangze OUYANG Yanran BAN Shuang CHEN 《Journal of Zhejiang University. Science. B》2022,23(5):353
Vascular endothelial growth factor (VEGF) is the main regulator of physiological angiogenesis during embryonic development, bone growth, and reproductive function, and it also participates in a series of pathological changes. Traditional Chinese medicine (TCM), with a history of more than 2000 years, has been widely used in clinical practice, while the exploration of its mechanisms has only begun. This review summarizes the research of recent years on the influence of TCM on VEGF. It is found that many Chinese medicines and recipes have a regulatory effect on VEGF, indicating that Chinese medicine has broad prospects as a complementary and alternative therapy, providing new treatment ideas for clinical applications and the theoretical basis for research on the mechanisms of TCM. 相似文献
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LIU Peng XIA Bing-jie TENG Zhao-wei 《浙江大学学报(A卷英文版)》2007,8(4):631-637
Floorplan, clock network and power plan are crucial steps in deep sub-micron system-on-chip design. A novel di- agonal floorplan is integrated to enhance the data sharing between different cores in system-on-chip. Custom clock network con- taining hand-adjusted buffers and variable routing rules is constructed to realize balanced synchronization. Effective power plan considering both IR drop and electromigration achieves high utilization and maintains power integrity in our MediaSoC. Using such methods, deep sub-micron design challenges are managed under a fast prototyping methodology, which greatly shortens the design cycle. 相似文献
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FDI技术溢出、人力资本与海西崛起 总被引:1,自引:0,他引:1
基于新古典经济增长理论模型,利用1981-2008年时间序列,分析FDI对福建经济增长的影响,结果表明:(1)相比于国内资本,FDI对福建经济增长的促进作用较小,中等人力资本与FDI结合并不能对经济增长带来好处,而高等人力资本与FDI的结合才能促进经济增长;(2)FDI能显著提高福建全要素生产率,人力资本水平越高、FDI占比越大越有利于全要素生产率的提高,同时,FDI的技术外溢效应的发挥离不开一定水平的人力资本支持。 相似文献
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基于线性插值的方法提出了一种适用于交替方向隐式时域有限差分法(ADI-FDTD)的吸收边界条件,该边界条件能够在ADI-FDTD方法中改善边界反射性能.首先,对由截断误差和相速估计误差引起的此吸收边界条件的反射进行了分析和推导.通过理论分析,说明了基于相速估计和非均匀网格的对此吸收边界改进方法能够改善边界条件的反射特性.然后进行了矩形波导情况下该吸收边界条件的数值仿真.最后给出了数值仿真结果,并通过对有无相速估计下吸收边界条件反射系数比较、对均匀和非均匀网格处理下吸收边界条件反射系数的比较,以及对在不同时间步长下吸收边界条件反射系数变化的分析,说明了该吸收边界条件及其改进方法对ADI-FDTD方法中的边界反射性能有很好的改善效果. 相似文献
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More efficient ground truth ROI image coding technique: implementation and wavelet based application analysis 总被引:1,自引:0,他引:1
KUMARAYAPA Ajith ZHANG Ye 《浙江大学学报(A卷英文版)》2007,8(6):835-840
In this paper, more efficient, low-complexity and reliable region of interest (ROI) image codec for compressing smooth low texture remote sensing images is proposed. We explore the efficiency of the modified ROI codec with respect to the selected set of convenient wavelet filters, which is a novel method. Such ROI coding experiment analysis representing low bit rate lossy to high quality lossless reconstruction with timing analysis is useful for improving remote sensing ground truth sur- veillance efficiency in terms of time and quality. The subjective [i.e. fair, five observer (HVS) evaluations using enhanced 3D picture view Hyper memory display technology] and the objective results revealed that for faster ground truth ROI coding applications, the Symlet-4 adaptation performs better than Biorthogonal 4.4 and Biorthogonal 6.8. However, the discrete Meyer wavelet adaptation is the best solution for delayed ROI image reconstructions. 相似文献
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In this paper, a distributed compressive spectrum sensing scheme in wideband cognitive radio networks is investigated. An
analog-to-information converters (AIC) RF front-end sampling structure is proposed which use parallel low rate analog to digital
conversions (ADCs) and fewer storage units for wideband spectrum signal sampling. The proposed scheme uses multiple low rate
congitive radios (CRs) collecting compressed samples through AICs distritbutedly and recover the signal spectrum jointly.
A general joint sparsity model is defined in this scenario, along with a universal recovery algorithm based on simultaneous
orthogonal matching pursuit (S-OMP). Numerical simulations show this algorithm outperforms current existing algorithms under
this model and works competently under other existing models. 相似文献
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提出了一种新的构造LDPC码的方法, 并把用该方法产生的LDPC码应用到编码正交频分复用(OFDM)系统中进行了研究. 该方法拓展了单位阵移位构造的LDPC码, 它利用简单的不等式可确保在置换单位阵构造中不会产生Tanner图中的短圈, 使得产生的LDPC码的Tanner图最小圈长为8. 由于该类码是准循环码以及其校验矩阵所固有的分层结构, 编码器和解码器都易于实现, 它们分别是线性可编和线性可译的. 所提出的LDPC码码率范围较大, 可以灵活选取. 利用迭代解码进行计算机仿真, 发现新的LDPC码比其他的规则LDPC码在编码OFDM系统中具有更好的性能. 相似文献
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