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水浸胁迫下植被高光谱遥感识别模型对比分析 被引量:11
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作者 蒋金豹 Michael D Steven +1 位作者 何汝艳 蔡庆空 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2013年第11期3106-3110,共5页
随着全球气候变暖,我国洪涝灾害发生的频率及影响范围都不断增加。通过野外模拟试验,研究植被(玉米、甜菜)在水浸胁迫下的光谱变化特征,以构建高光谱遥感模型对水涝灾害范围进行监测。试验于2008年5月—8月在英国诺丁汉大学Sutton Bonin... 随着全球气候变暖,我国洪涝灾害发生的频率及影响范围都不断增加。通过野外模拟试验,研究植被(玉米、甜菜)在水浸胁迫下的光谱变化特征,以构建高光谱遥感模型对水涝灾害范围进行监测。试验于2008年5月—8月在英国诺丁汉大学Sutton Bonington校区(52.8°N,1.2°W)进行,每周采集一次样本并在室内测量其光谱数据。试验结果表明植被光谱在550,800~1 300nm区域反射率都稍有降低,而在680nm区域反射率则略微增大。选取NDVI,SIPI,PRI,SRPI,GNDVI及R800*R550/R680共六个植被指数识别水浸胁迫下的植被,研究表明,指数SIPI与R800*R550/R680对水浸胁迫玉米比较敏感,而指数SIPI,PRI及R800*R550/R680对水浸胁迫甜菜比较敏感。为寻找最优的识别模型,计算对照与水浸胁迫植被指数之间的归一化均值距离并进行对比分析,发现植被指数R800*R550/R680的归一化均值距离在胁迫早期即大于其他指数的距离,说明该指数识别水浸胁迫植被的能力优于其他指数,且具有较强的敏感性与稳健性。因此,可以利用该指数快速地提取水浸面积,为救灾减灾决策提供信息支持。 展开更多
关键词 光谱特征 水浸胁迫 植被 识别模型对比分析 归一化均值距离
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论财务预警系统的功能及其建设 被引量:20
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作者 吴晓梅 《计划与市场》 2002年第6期43-44,共2页
现代企业财务管理理念特别强调对经济活动的事前预测和事中控制,力求将其运行纳入预先规划的轨道,以期达到低风险、高效率实现企业目标的目的。建立和健全财务预警系统是其中的有效途径之一。一、财务预警系统的功能财务预警系统是以企... 现代企业财务管理理念特别强调对经济活动的事前预测和事中控制,力求将其运行纳入预先规划的轨道,以期达到低风险、高效率实现企业目标的目的。建立和健全财务预警系统是其中的有效途径之一。一、财务预警系统的功能财务预警系统是以企业信息化为基础,对企业在经营管理活动中潜在的风险进行适时监控以防止财务失败的系统。一般说来,企业财务预警系统有以下几种功能:(一)监测功能 根据预先设计的财务预警指标体系,收集整理各种静态数据和动态信息,以实现对经营过程的适时跟踪监控。 展开更多
关键词 财务预警系统 功能 企业 财务预警指标体系 指标警戒值 预警报告 分析识别模型
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地下水水质的物元评价方法及应用 被引量:21
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作者 邹同庆 《常德师范学院学报(自然科学版)》 2001年第4期31-34,共4页
运用可拓学理论,论述了物元分析识别评判模型,建立了地下水水质评判的关联函数,为定量评价地下水水质提供了科学依据。给出了评价实例。并与地下水水质质量评价的灰色聚类方法、模糊数学方法进行了比较。
关键词 地下水 水质评价 关联函数 物元分析识别评判模型 综合评价
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Phase Analysis and Identification Method for Multiphase Batch Processes with Partitioning Multi-way Principal Component Analysis (MPCA) Model 被引量:2
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作者 董伟威 姚远 高福荣 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第6期1121-1127,共7页
Multi-way principal component analysis (MPCA) is the most widely utilized multivariate statistical process control method for batch processes. Previous research on MPCA has commonly agreed that it is not a suitable me... Multi-way principal component analysis (MPCA) is the most widely utilized multivariate statistical process control method for batch processes. Previous research on MPCA has commonly agreed that it is not a suitable method for multiphase batch process analysis. In this paper, abundant phase information is revealed by way of partitioning MPCA model, and a new phase identification method based on global dynamic information is proposed. The application to injection molding shows that it is a feasible and effective method for multiphase batch process knowledge understanding, phase division and process monitoring. 展开更多
关键词 batch process multi-way principal component analysis MULTIPHASE process monitoring
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GIS-based Analysis for Hotspot Identification of Tradeoff Between Ecosystem Services: A Case Study in Yanhe Basin, China 被引量:13
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作者 ZHENG Zhenmin FU Bojie FENG Xiaoming 《Chinese Geographical Science》 SCIE CSCD 2016年第4期466-477,共12页
Although the quantification and valuation of ecosystem services have been studied for a long time, few studies have specifi- cally focused on the quantification of tradeoffs between ecosystem services and tradeoff hot... Although the quantification and valuation of ecosystem services have been studied for a long time, few studies have specifi- cally focused on the quantification of tradeoffs between ecosystem services and tradeoff hotspots, Based on previous studies of ecosys- tem service assessment, we proposed a feasible method to analyze the tradeoffs between ecosystem services, including determination of their relationship, quantification of tradeoffs, and identification of tradeoff hotspots. Potential influencing factors were then further ana- lyzed. The Yanhe Basin in the Loess Plateau was selected as an example to demonstrate the application process. Firstly, the amounts of net primary production (NPP) and water yield (WY) in 2000 and 2008 were estimated by using biophysical models, Secondly, correla- tion analysis was used to indicate the tradeoffs between NPP and WY. Thirdly, tradeoff index (TINpp/wy) was established to quantify the extent of tradeoffs between NPP and WY, and the average value of TINpp/wy is 24.4 g/(mm·m2) for the Yanhe Basin between 2000 and 2008. Finally, the tradeoff hotspots were identified. The results indicated that the area of lowest tradeoff index concentrated in the mid- dle part of the Yanhe Basin and marginal areas of the southern basin. Map overlapping was used for preliminary analysis to seek poten- tial influencing factors, and the results showed that shrub was the best suited for growing in the Yanhe Basin, but also was a potential irtfluencing factor for formulatiort of the tradeoff hotspots. The concept of tradeoff index could also be used to quantify the degree of synergy between different ecosystem services. The method to identify the tradeoff hotspots could help us to narrow the scope of study area for further research on the relationship among ecosystem services and concentrate on the potential factors for formation of tradeoff between ecosystem services, enhance the capacity to maintain the sustainability of ecosystem. 展开更多
关键词 correlation analysis net primary productivity water yield tradeoff index inlluencing tactor
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企业财务风险分析与防范——以W公司为例 被引量:1
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作者 孔颖 《商场现代化》 2022年第1期146-148,共3页
当今世界经济全球化以非常快的速度发展,世界各地的企业每时每刻都在面临多方因素所带来的财务风险。财务风险发生于企业日常的生产经营活动,对一个企业的长远发展有着重要的影响,因而企业必须对财务风险有一个全方位的认识,从而制定出... 当今世界经济全球化以非常快的速度发展,世界各地的企业每时每刻都在面临多方因素所带来的财务风险。财务风险发生于企业日常的生产经营活动,对一个企业的长远发展有着重要的影响,因而企业必须对财务风险有一个全方位的认识,从而制定出相应的措施来防范财务风险。企业应该预先制定计划,将财务风险控制在一个合适的范围,加强对财务工作的管理,最大限度地降低生产经营过程中所面临的风险,从而保证企业实现利润最大化的目标,并且为企业的长期稳定发展提供保障。 展开更多
关键词 财务风险 单变量模型分析识别 防范措施
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