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1.
为使通信设备能安全稳定运行、无人职守机房故障能被及时地发现,通过对集中监控系统的构成、监控内容进行详细研究,开发了基于网络的通信电源监测软件。基本实现了被监控设备和被监测信号遥测、遥感、遥控。  相似文献   

2.
我国农作物遥感估产研究进展   总被引:1,自引:0,他引:1  
概述了遥感在我国农作物长势监测、种植面积测算和产量估算等方面的应用和研究进展,同时分析了近来MODIS在农作物遥感估产方面的应用和存在的问题。展望了我国遥感估产的研究及发展方向,认为3S技术一体化、高光谱遥感、定量遥感是今后遥感估产应用的发展方向。  相似文献   

3.
农田生态系统模型与农业资源高效利用   总被引:9,自引:0,他引:9  
在过去的几十年中,系统分析方法在农业研究中的应用有了较大的发展。在各种不同领域使用系统分析方法的科学家发展许多不同类型的模型,其中有概念的、综合性和概化的。模型的意义是在不同尺度上整合多学科的研究结果。概化模型用于土利用的定量评价和在更高的尺度上的资源管理研究。其它模型可以为政策制定者提供战略的和技术的决策支持。作为信息技术和地学方法在农业中的应用,作物生长模型的研发是面向农田生态系统中的资源管理。其目标是应用系统分析方法,以作物生长模型为核心,以区域资源环境数据库为基础,建立基于遥感和地理信息系统的决策支持系统和作物长势监测与产量预报系统。  相似文献   

4.
星基遥感技术在获取时空复杂多变的水信息方面具有独特的优势,如TRMM/GPM,SMAP,GRACE,SWOT,GRACE-II,PATH,TERRA,AQUA,以及国内的风云系列等环境卫星提供了前所未有的全球遥感水文大数据.为了进一步促进遥感技术在水循环研究和水资源管理中的应用,促进学科交叉和系统集成研究,本文系统综述国际前沿的全球水循环遥感卫星技术、遥感参数反演及其在水文中的潜在应用等,重点介绍降水、土壤湿度、蒸散、地下水、水面高程、冰川、云和大气水等遥感技术,同时探讨全球水循环观测卫星的研发和功能,分析数据同化、遥感反演参数不确定性方面的技术瓶颈及未来展望.  相似文献   

5.
作为网构软件的基本特性之一,自适应性是指软件系统在预设策略的指导下自动地监测系统状态信息,并在必要时对自身进行调整,以提供更好的服务.针对网构软件可适应性、自适应可操作性及适应结果可信性3个基本问题,提出了一种以体系结构为中心的网构软件自适应方法,即监测、分析、规划、实施等自适应活动均围绕软件体系结构展开,其中,网构软件运行状态和行为以运行时软件体系结构的方式实时展现和在线调整;自适应相关知识通过软件体系结构记录、组织和加工,以实现系统状态和行为的自动分析和调整规划.  相似文献   

6.
首先介绍了农田渍害的表现特征;其次根据监测原理,将国内外农田溃害遥感监测的主要方法分为地表指示标志法、地下水位反演法和与非遥感方法相结合的综合分析法,并分别对各类方法的原理、技术、适用范围及优缺点进行分析,发现各种方法均能解决特定的农田渍害监测问题,同时也存在着缺陷和局限性;最后,进行了总结并指出了两种潜在的遥感监测方...  相似文献   

7.
静止卫星的海洋水色观测计划   总被引:1,自引:0,他引:1  
海洋现象的时空尺度分析表明目前以极轨方式运行的海洋水色卫星遥感不能完全满足沿海及海岸带地区管理和研究的需要.采用静止卫星作为水色遥感观测的平台对沿海和海岸带进行高频率的遥感观测,可以满足海岸带生物物理过程研究和调查所需观测频度的要求,有利于确定潮汐混合条件,建立新的模型,探测短时间尺度的生物物理现象,改变现有的海岸带管理方式,实现海岸带资源的科学管理,具有极轨卫星不可具备的优势.本文简单介绍了韩国预计发射的静止水色成像仪KGOCI和美国GOES-R卫星计划的HES-CW,同时希望我国能早日研制发射出自主的静止水色观测卫星和传感器,为我国漫长的海岸带监测提供利剑.  相似文献   

8.
准确诊断作物氮素营养状况是实现氮肥优化管理的前提.遥感可全覆盖、大面积同步监测作物多种形态和理化参数.将其应用于氮素营养诊断,对指导施肥管理具有重要意义.基于遥感手段开展作物氮素营养诊断研究已有几十年,将其成果加以总结,并分析存在的问题,有利于更好地促进遥感技术在该领域中应用.本文综述了基于遥感的作物氮素营养诊断技术发展现状,分析提炼了科学问题,在此基础上提出了本领域若干研究方向,期望能对相关领域研究者有所启发.  相似文献   

9.
网络化制造系统对于工业制造业的影响长远而又深刻,尤其是近50年以来,世界各国都在研发适应国内供应链生产以及国际化全球制造的网络化制造系统,以期能够突破传统以流水线批量生产为代表的主流生产方式,充分利用工业系统中各层级闲置的制造资源,建立竞争优势.本文在分析总结网络化制造研究现状和发展趋势的基础上,提出了基于数据驱动的网络化制造系统总体架构,构建了以工业云大数据中心为核心的网络化制造系统云边运行体系.接着,在网络化制造系统的运行流程中引入了关键的主体性原则,探索并研究了“网络化制造系统究竟该如何运行”和“主体如何参与网络化制造流程”这两个重要的科学问题.进一步地,设计了网络化制造系统的部署模式,并进行了实验验证.最后,讨论了该原型系统的内涵与基于数据驱动的运行方式,同时指出重视主体性原则才是实现网络化制造运行的根本,深度挖掘主体特征将是网络化制造系统升级转变的关键.  相似文献   

10.
随着对地观测技术的发展,人类获取遥感数据的途径和方式也越来越多,遥感数据呈现出大数据的特征.本文通过对大规模多源遥感数据应用所面对的问题进行分析,总结出遥感数据具有总量大、来源多与文件格式不一致、多尺度与投影方式多样、结构复杂以及与其他领域数据具有较大差异等特点.针对大规模多源遥感数据的协同处理应用,提出了解决这类应用需要在统一的数据结构及抽象层次、生产及管理的统一剖分参考框架和分布式高性能处理3个方面开展工作,并介绍了多源数据协同定量遥感产品生产系统在这3方面的实现途径.  相似文献   

11.
The delayed release of the National Account data for GDP is an impediment to the early understanding of the economic situation. In the short run, this information gap may be at least partially eliminated by bridge models (BM) which exploit the information content of timely updated monthly indicators. In this paper we examine the forecasting ability of BM for GDP growth in the G7 countries and compare their performance to that of univariate and multivariate statistical benchmark models. We run four alternative one‐quarter‐ahead forecasting experiments to assess BM performance in situations as close as possible to the actual forecasting activity. BM are estimated for GDP both for single countries (USA, Japan, Germany, France, UK, Italy and Canada), and area‐wide (G7, European Union, and Euro area). BM forecasting ability is always superior to that of benchmark models, provided that at least some monthly indicator data are available over the forecasting horizon. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

12.
As the 1990-91 Gulf crisis has emphasized, the risk of new oil shocks remains high in the medium to long run. Although energy intensity has decreased in the major countries since the first two oil shocks, the simulation performed with the MIMOSA world model, which is described in this paper, shows that a permanent rise in oil prices still induces direct strong negative consequences in the OECD: a temporary recession, a durable loss in production and employment and a lasting rise in inflation. Moreover, according to the model and due to national dissimilarities, an oil shock in Europe has some asymmetrical effects which are pointed out here. Further simulations test two different economic policy responses in the OECD: a ‘beggar-thy-neighbor’ policy in which each country tries to ‘export’ its unemployment by curbing domestic inflation and wage growth; and a co-ordinated policy supporting both supply and demand. The first leads to a general deflationist overshooting. The second ensures stabilization with a much lower cost in employment.  相似文献   

13.
详细介绍了一种家居安防监视系统的硬件设计.该系统使用主控芯片STM32F103和模块M33,实现了图像采集和处理、GSM/GPRS通讯、短距离无线通讯、人机交互信息显示、红外感应、外部电源和内部锂电池供电等功能.实际运行表明,该系统具有可靠性好、功能强、成本低、安装和使用方便的特点,满足了人们对家居安防产品的要求.  相似文献   

14.
Summary Bacterial mutagenicity assay to detect potential chronic toxicity of a potent, new, benzoyl urea insect growth regulator (CGA-112913 or IKI-7899, formerly UC-62644) was conducted using 5 histidine auxotrophs ofSalmonella typhimurium. Tests within the concentration range of 0.9–500 g (saturating)/plate of the compound with and without the 5–9 mammalian metabolic activation system showed no mutagenic effects clearing the way for long-term chronic toxicology studies.The authors thank Professor Bruce N. Ames for supplying the tester strains together with all the relevant information for conducting the bioassays and Ms. Norma Charlebois for her meticulous technical assistance.  相似文献   

15.
In this paper, we forecast real house price growth of 16 OECD countries using information from domestic macroeconomic indicators and global measures of the housing market. Consistent with the findings for the US housing market, we find that the forecasts from an autoregressive model dominate the forecasts from the random walk model for most of the countries in our sample. More importantly, we find that the forecasts from a bivariate model that includes economically important domestic macroeconomic variables and two global indicators of the housing market significantly improve upon the univariate autoregressive model forecasts. Among all the variables, the mean square forecast error from the model with the country's domestic interest rates has the best performance for most of the countries. The country's income, industrial production, and stock markets are also found to have valuable information about the future movements in real house price growth. There is also some evidence supporting the influence of the global housing price growth in out‐of‐sample forecasting of real house price growth in these OECD countries.  相似文献   

16.
A large proportion of the world telecommunications market can be characterized as supply restricted. In ITU (1999) official waiting lists numbered about 50 million worldwide with an average waiting time of two years. More than 100 countries had not eliminated the waiting list for telephone connections and hence a supply restricted market prevailed in all of these countries. Only about 25 countries have succeeded in eradicating their waiting list for basic telephone service. In terms of the pattern of diffusion, the subscriber's flow from waiting applicants to adopters is controlled by supply restrictions adding an important dimension that needs to be addressed when modeling and forecasting demand. An empirical analysis of the diffusion of main telephones in 46 supply‐restricted countries is presented to demonstrate the usefulness of a three‐stage Bass model that has been proposed to capture the dynamics of supply restrictions. We also compare the forecasting ability of different approaches to estimation when panel data are available. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

17.
Summary Through their catalytic abilities microbes can increase rates of chemical reactions which would take a very long time to reach equilibrium under abiotic conditions. Microbes also alter the concentration and composition of chemicals in the environment, thereby creating new conditions for further biological and chemical reactions. Rates of degradation and possible indirect consequences on leaching rates in waste repositories are a function of the presence or absence of microbes and of the conditions which allow them to become catalytically active.Microbially mediated reactions are no exception to the rule that all chemical processes are basically governed by thermodynamic laws. Naturally occurring processes proceed in the direction that leads to the minimal potential energy level attained when equilibrium is reached. A continuous supply of energy to an ecosystem in the form of biochemically unstable compounds maintains non-equilibrium conditions, a prerequisite for all chemotrophic life. Energy is released as a chemical reaction progresses towards equilibrium. Microbes scavenge that portion of the free energy of reaction (Gr) which can be converted into biochemically usable forms during the chemical oxidation processes. As electrontransfer catalysts, the microorganisms mediate reactions which are thermodynamically possible thereby stimulating reaction rates. Decomposition and mineralization in systems without a continuous supply of substrates and oxidants will lead to equilibria with minimal free energy levels at which point further microbial action would cease. The differences in the free energy levels of reactions (Gr), represent the maximal energy which is available to microorganisms for maintenance and growth. How much of the released free energy will be conserved in energy-rich bonds, compounds (e.g. ATP), and chemical potentials (e.g. emf) useful for biosynthesis and biological work is characteristic for the microbes involved and the processes and metabolic routes employed.Materials whose elements are not present in the most oxidized form attainable in the oxic environment of our planet are potentially reactive. Microbial activities are associated only with chemical reactions whose free energy changes are exergonic. This should be kept in mind for all investigations related to the role of microbes in repositories or in the layout of proper waste storage conditions. Rigorous application of thermodynamic concepts to environmental microbiology allows one to develop models and design experiments which are often difficult to conceive of in complex natural systems from physiological information alone. Thermodynamic considerations also aid in selecting proper deposition conditions and in carrying out thoughtful experiments in areas related to microbial ecology of waste repositories.  相似文献   

18.
在目前的信息化时代,传统的交通运输方式已经阻碍了社会的发展,城市的交通拥堵、环境污染以及电子商务(e-business)的物流瓶颈等也都是困扰大城市的首要问题。为此,许多国家正在研究管道物流系统,特别是城市地下管道物流运输系统,更是一个十分新颖的研究领域。本文介绍了国外管道物流的发展历史及研究现状,分析了地下管道物流研究要解决的关键问题主要集中在工程规划建设和相关技术、自动化传输和监控技术和成本效益分析三个方面。本世纪大力发展和全面推动城市地下管道物流系统建设的技术条件已基本成熟,地下管道物流将是一个具有划时代意义的研究与发展领域。  相似文献   

19.
This paper examines the problem of forecasting macro‐variables which are observed monthly (or quarterly) and result from geographical and sectorial aggregation. The aim is to formulate a methodology whereby all relevant information gathered in this context could provide more accurate forecasts, be frequently updated, and include a disaggregated explanation as useful information for decision‐making. The appropriate treatment of the resulting disaggregated data set requires vector modelling, which captures the long‐run restrictions between the different time series and the short‐term correlations existing between their stationary transformations. Frequently, due to a lack of degrees of freedom, the vector model must be restricted to a block‐diagonal vector model. This methodology is applied in this paper to inflation in the euro area, and shows that disaggregated models with cointegration restrictions improve accuracy in forecasting aggregate macro‐variables. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

20.
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