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SQL Server数据备份策略的选择 被引量:8
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作者 罗小平 王福兆 《计算机系统应用》 2005年第5期74-75,共2页
本文所讨论的备份,不单指利用SQL Server的"备份工具"备份数据,而是泛指使用各种方法将指定的SQL Server数据库保存起来,供数据恢复或移植之用。这里介绍几种常见的数据备份策略,不仅简单,而且易于实现。
关键词 SQL Server 数据备份策略 恢复 关系数据库管理系统 “导出数据” “备份工具”
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A data-derived soft-sensor method for monitoring effluent total phosphorus 被引量:5
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作者 Shuguang Zhu Honggui Han +1 位作者 Min Guo Junfei Qiao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第12期1791-1797,共7页
The effluent total phosphorus(ETP) is an important parameter to evaluate the performance of wastewater treatment process(WWTP). In this study, a novel method, using a data-derived soft-sensor method, is proposed to ob... The effluent total phosphorus(ETP) is an important parameter to evaluate the performance of wastewater treatment process(WWTP). In this study, a novel method, using a data-derived soft-sensor method, is proposed to obtain the reliable values of ETP online. First, a partial least square(PLS) method is introduced to select the related secondary variables of ETP based on the experimental data. Second, a radial basis function neural network(RBFNN) is developed to identify the relationship between the related secondary variables and ETP. This RBFNN easily optimizes the model parameters to improve the generalization ability of the soft-sensor. Finally, a monitoring system, based on the above PLS and RBFNN, named PLS-RBFNN-based soft-sensor system, is developed and tested in a real WWTP. Experimental results show that the proposed monitoring system can obtain the values of ETP online and own better predicting performance than some existing methods. 展开更多
关键词 Data-derived soft-sensor Effluent total phosphorus Wastewater treatment process Radial basis function neural network Partial least square method
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Multiple Cropping Intensity in China Derived from Agro-meteorological Observations and MODIS Data 被引量:11
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作者 YAN Huimin XIAO Xiangming +3 位作者 HUANG Heqing LIU Jiyuan CHEN Jingqing BAI Xuehong 《Chinese Geographical Science》 SCIE CSCD 2014年第2期205-219,共15页
Double-and triple-cropping in a year have played a very important role in meeting the rising need for food in China.However,the intensified agricultural practices have significantly altered biogeochemical cycles and s... Double-and triple-cropping in a year have played a very important role in meeting the rising need for food in China.However,the intensified agricultural practices have significantly altered biogeochemical cycles and soil quality.Understanding and mapping cropping intensity in China′s agricultural systems are therefore necessary to better estimate carbon,nitrogen and water fluxes within agro-ecosystems on the national scale.In this study,we investigated the spatial pattern of crop calendar and multiple cropping rotations in China using phenological records from 394 agro-meteorological stations(AMSs)across China.The results from the analysis of in situ field observations were used to develop a new algorithm that identifies the spatial distribution of multiple cropping in China from moderate resolution imaging spectroradiometer(MODIS)time series data with a 500 m spatial resolution and an 8-day temporal resolution.According to the MODIS-derived multiple cropping distribution in 2002,the proportion of cropland cultivated with multiple crops reached 34%in China.Double-cropping accounted for approximately 94.6%and triple-cropping for 5.4%.The results demonstrat that MODIS EVI(Enhanced Vegetation Index)time series data have the capability and potential to delineate the dynamics of double-and triple-cropping practices.The resultant multiple cropping map could be used to evaluate the impacts of agricultural intensification on biogeochemical cycles. 展开更多
关键词 agricultural intensification multiple-cropping crop calendar agro-meteorological observation moderate resolution imaging spectroradiometer(MODIS)
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