一种实现工业数字摄影测量自动化的方法     

LU Cheng-jing  HUANG Gui-ping  LI Guang-yun  CONG Dian-wei  Fan Sheng-hong 《测绘学院学报》2008,(3)

在工业数字摄影测量中,当被测物大而复杂时,目标像片的数量可能达到数百张,像点达到几千个,因此人工去识别这些像点是不切实际的,不但费工费时而且也加大了出错率。为了实现工业数字摄影测量的自动化,引入了一种点状编码标志,讲述了其设计原理,并应用透视投影中交比不变量和仿射变换对其进行了识别。试验表明,该编码标志点设计严密,自动识别率为100%,可以满足应用要求。  相似文献   

Cs+水合结构密度泛函理论计算研究          下载免费PDF全文

张文倩  房春晖  周永全  朱发岩  刘红艳 《盐湖研究》2018,26(3)

本文用密度泛函理论在WB97XD/gen def2-tzvp基组水平上对[Cs(H2O) n] +(n=1-15)水合团簇结构的振动光谱进行了研究。研究表明,随着水分子数的增加,在气相和液相中,8配位的Cs+ 水合团簇是最稳定的;随着水分子数的增加,Cs-O键长增大,Cs+上的电荷密度减小。当水分子数大于11时,Cs-O键长和Cs+上的电荷密度变化很小。O(H2O)-O(H2O)距离、∠O(H2O)-Cs-O(H2O)°统计结果表明,15个水分子足以形成Cs+的近似饱和水合层。此外,红外光谱显示[Cs(H2O)n]+水合团簇中O-H伸缩振动随着水分子数的增加而发生变化,由此可以作为鉴别水合层位置的一种参考方法。  相似文献   

利用旋转不变特征提取全极化SAR影像人工地物     

车美琴  阿里木&#;赛买提  杜培军  罗洁琼  鲍蕊 《遥感学报》2016,20(2):303-314

  相似文献   

高光谱遥感影像海上舰船目标检测算法的研究   总被引：1，自引：0，他引：1  

路威  余旭初  马永刚  刘娟 《海洋测绘》2005,25(4):8-12

提出一种基于独立分量分析的高光谱遥感影像海上舰船目标检测方法。首先借助快速独立分量分析(FICA),将高维数据中隐藏的舰船目标信息集中投影到低维特征影像中,然后以峰度为特征度量指标选择特征影像,最后用以偏斜为指标的直方图分割方法提取舰船目标。实验证明,此算法精度较高,适用于对杂波背景中的舰船目标进行提取。  相似文献   

福建省铁帽山钼矿床地质、地球化学异常特征与找矿方向研究   总被引：2，自引：0，他引：2  

刘鹤  姚敬金  任宏  刘碧洪 《地球学报》2014,35(6):683-692

福建铁帽山钼矿床位于闽西南拗陷带,是一个与晚侏罗世中酸性侵入岩有关的斑岩型钼矿床。矿体产出于花岗杂岩体中,杂岩体由中粗粒二长花岗岩、中粗粒钾长花岗岩、花岗斑岩和少量石英闪长岩组成,钼矿体围绕着矿区中部的花岗斑岩岩株近似呈环状分布,主要赋存于蚀变的二长花岗岩中。矿体受到后期断裂构造的破坏而被截断。矿区的围岩蚀变作用强烈,并具有明显的分带特征,自下而上、由内到外可划分为钾化带、石英-伊利石化带、蒙脱石化带和高岭石化带。其中,石英-伊利石化作用与钼矿化作用的关系最为密切。土壤地球化学测量结果显示,Mo元素对数值的频率统计呈双峰式分布,异常下限为12.2×10–6,由此圈定的Mo元素异常近似呈环状分布,与矿体分布范围总体上相一致;而低温成矿元素Zn、Ag元素和高温成矿元素Sn的异常多数分布于Mo元素环状异常的外围和中心低值区。在勘查工作中,石英-伊利石化蚀变和Mo元素地球化学异常可以作为最重要的找矿标志,同时要特别注意断层对矿体的截断和破坏作用。  相似文献   

Uncertainties in global warming science and near-term emission policies     

L. D. Danny Harvey 《Climate Policy》2013,13(5):573-584

Abstract

It is argued here that stringent, early emission reductions are necessary in order to minimize ‘dangerous anthropogenic interference in the climate system’ (DAI), the stated Objective of Article 2 of the UNFCCC (United Nations Framework Convention on Climate Change). Given probability distribution functions (pdfs) for climate sensitivity and the temperature threshold for harm consistent with currently available evidence, and accepting a 10% risk of unacceptable damage as the threshold for ‘danger’, it is not possible to avoid DAI. Having adopted a precautionary approach in setting emission trajectories, the possibility arises that future resolution of uncertainties concerning climate sensitivity and the harm threshold may show the climate sensitivity to be low (1–2 K) and the harm threshold high (2 K rather than 1 K). Using a simple coupled climate-carbon cycle model, it is shown that if the climate sensitivity were to be definitively determined to be 2 K in 2020, then the emission reductions achieved by that time and planned for the next two decades are still fully needed. Only if climate sensitivity is very low (1 K) and the harm threshold is high (2 K) would the emissions achieved by 2020 not have been fully necessary. However, this would still lead to changes in ocean chemistry that are likely to be highly detrimental to marine life. Thus, when the full spectrum of impacts is considered, there is no plausible set of assumptions under which stringent near-term emission reductions are rendered unnecessary.  相似文献   

Joint Implementation in Ukraine: national benefits and implications for further climate pacts     

Vicki Duscha  Joachim Schleich 《Climate Policy》2013,13(3):305-327

The contribution that no-lose target schemes for non-Annex I (NAI) countries could make to achieve the 2°C target is explored by accounting for the incentives of 18 NAI countries’ participation in no-lose target schemes. Using various scenarios, it is shown that implementing uniform no-lose targets as part of the burden-sharing will not lead to global emissions levels compatible with the 2°C target, because uniform no-lose targets will only be beneficial to a few NAI countries. Employing more lenient uniform no-lose targets or individual no-lose targets for large emitters could increase participation by NAI countries and decrease global emissions, global compliance costs, rents by NAI countries, and compliance costs for Annex I (AI) countries. However, the resulting global emissions levels will not be compatible with attaining the 2°C target. Achieving this target will require more stringent emissions targets for AI countries and more lenient no-lose targets for NAI countries. As such, no-lose targets should account for 20% to 47% of global emissions reductions, while due to emissions trading around two-thirds of global emissions reductions should be realized in NAI countries. Indeed, an effective solution may only require no-lose targets for five to seven of the largest NAI countries.

Policy relevance

No-lose targets are one of a number of instruments discussed under the United Nations Framework Convention on Climate Change New Market Mechanism to integrate NAI countries in global emissions reduction efforts. In contrast to binding reduction targets, which apply penalties if a target is not met, no-lose targets provide incentives for meeting a target, e.g. in the form of excess emissions certificates that can be sold on the global carbon market. The presented simulations show that no-lose targets can result in contributions from NAI countries to global emissions reduction efforts. However, the simulations also show that the necessary incentives for no-lose targets need to be adjusted. AI countries require more ambitious targets and NAI countries require less ambitious no-lose targets than proposed by the Intergovernmental Panel on Climate Change report. Effective no-lose targets may only be required for five to seven of the largest NAI countries.  相似文献   

The emperor's new clothes: redressing the Kyoto Protocol     

《Climate Policy》2013,13(2-3):161-177

Abstract

US President Bush repudiated the Kyoto Protocol because, in his view, it is ‘fatally flawed in fundamental ways’. This paper evaluates seven proposals to redress the protocol according to their potential to deal with three key issues that have reinforced US intransigence: hot air, cost uncertainty and developing country participation. It argues that negotiations on intensity targets hold the most promise. Because intensity targets limit hot air, but do not limit economic growth, and a high variance of carbon intensity exists among countries with similar GDP per capita, intensity targets based on best practice levels might be agreeable to developing countries and the US. If a protocol specifying such targets were implemented, less warming would be associated with larger world GDP than would otherwise be the case, and countries' carbon intensity and emissions per capita would tend to converge to best practice levels at every stage of development.  相似文献   

Sediment targets for informing river catchment management: international experience and prospects   总被引：3，自引：0，他引：3  

A. L. Collins  P. S. Naden  D. A. Sear  J. I. Jones  I. D. L. Foster  K. Morrow 《水文研究》2011,25(13):2112-2129

Sediment plays a pivotal role in determining the physical, chemical and biological integrity of aquatic ecosystems. A range of factors influences the impacts of sediment pressures on aquatic biota, including concentration, duration of exposure, composition and particle size. In recognition of the need to assess environmental status for sediment and mitigate excessive sediment pressures on aquatic habitats, both water column and river substrate metrics have been proposed as river sediment targets. Water column metrics include light penetration, turbidity, sediment concentration summary statistics and sediment regimes. Substrate metrics include embeddedness, the fredle index and riffle stability. Identification of meaningful numeric targets along these lines has, however, been undermined by various issues including the uncertainty associated with toxicological dose‐response profiles and the impracticalities of deploying statistically robust sampling strategies capable of supporting catchment‐scale targets. Many of the thresholds reported are based on correlative relationships that fail to capture the specific mechanisms controlling sediment impacts on aquatic habitats and are stationary in nature. Temporal windows represented by the key life stages of specific species must be given greater emphasis. Given such issues and the need to support the revision of sediment targets for river catchment management, it is proposed that greater emphasis should be placed on developing generic modelling toolkits with the functionality for coupling current or future projected sediment regimes with biological response for a range of biota. Such tools should permit the identification of river catchment‐specific targets within a national context, based on biological effect and incorporate sufficient flexibility for utilizing updated physical, chemical, biological and catchment attribute data. Confidence will continue to be required in compliance screening to ensure cost‐effective management programmes for avoiding disproportionate investment in impacted river catchments. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

石灰改性膨胀土击实曲线的双峰特性研究     

程钰  石名磊 《岩土力学》2011,32(4):979-0983

膨胀土掺石灰改性之后,其粉粒组的含量显著增加。当采用湿法击实时,由于土体保持了原有的结构性并表现出粉土的特性,在某个较低含水率时,击实功没有超过破坏其结构性的程度,出现一个干密度峰值。随着含水率的增加,击实功破坏了土的结构性,土体重新压实,曲线出现了另一个大干密度的峰值。因此,击实曲线表现出不稳定的双峰现象,从而降低了击实曲线的实用性及可靠性。然而采用修正湿法得到的击实标准,相对于湿法更加合理,相对于干法更加实用可靠,为工程施工质量控制与路基工后质量评价提供了更加有效的方法  相似文献