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51.
灰色关联分析法在海洋环境质量评价中的应用   总被引:2,自引:0,他引:2  
介绍了灰色关联分析法的原理,说明了其评价步骤。以青岛某海区海水水质评价为例阐明了该方法在海洋环境评价中的应用,并将评价结果与模糊综合评价结果加以比较,结果表明,两种评价方法的评价结果有着较明显的差别,分析了原因。本文还提出了海水污染防治措施,为海洋环境保护提供依据。  相似文献   
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53.
如何计算整个系统的运转效率,特别是受不确定因素影响的系统(如过驳系统),仍然是一个非常重要的研究课题。文章提出基于模糊综合评判方法的效率计算方法,是一种新的尝试,这种方法较好的避免了人的主观随意性,更符合实际情况,同时又可以弥补统计方法的不足。文章对某沿海地区的一过驳系统进行了效率计算,取得比较好的效果。  相似文献   
54.
In recent years, bulk carriers have been identified with high risks of catastrophic structural failure and foundering, and with heavy loss of human life. This study, based upon Lloyd's of London casualty records, identified four risk factors that had significant, independent effect upon the likelihood of a bulk carrier foundering. The risk of foundering increased with the age of the ship, and was related to the ship's flag of registration. Most importantly, however, increased risks were found for heavy cargoes of iron ore and scrap steel or iron, and for trading routes to the Far East and from Europe to North America. Additional safety measures, in particular regarding ship design and high-risk trades, may well be necessary to reduce the high casualty rates.  相似文献   
55.
The working group Mathematical Geology of the Freie Universität Berlin was formed in 1971. We review quantitative methods used by the working group since 1983 to treat mineral exploration problems. The methods applied vary from elementary statistical analysis of multivariate exploration data to optimal strategies for selecting favorable targets, and from multiobjective decision-making for additional drill hole locations to expert systems in exploration.The methods applied are directly related to the level of information at each stage of the exploration process. Special emphasis was placed on the relationship between and evaluation of subjective and objective data. Case studies illustrating the various methods are presented for different kinds of mineral deposits and exploration environments.  相似文献   
56.
Pollution index is a powerful tool for ecological geochemistry assessment. The commonly used pollution indices by heavy metals in soils and sediments were classified as two types of single index and integrated index in an algorithm point of view. Four single indices of contamination factor (or concentration factor), ecological risk factor, enrichment factor, and index of geo-accumulation were illustrated, and the reference values for calculating single indices were distinguished into background levels and threshold pollution values. Eight integrated indices were divided into two groups. One group is suitable for the normal distribution single indices including the sum, average, weighted average,vector modulus, and Nemerow pollution indices, and the other for log-normal distribution including the product, root of product, and weighted power product pollution indices. Using background levels as reference values, five contamination classes were divided, and the terminologies are suggested for the single and integrated indices to unify the assessment results. Software of EGAPI was developed in a single document interface to calculate the four single and eight integrated indices by heavy metals to assess the quality of soil and sediment ecological geochemistry. Pollution indices by heavy metals of Cu,Pb, and Zn in soils in parks of Beijing were calculated using EGAPI software, and these five contamination classes and terminologies suggested in this study were evaluated and used. Results ofintegrated indices of Cu, Pb, and Zn in soils indicated that the soil qualities are unpolluted as a whole and varied from low polluted to unpolluted status from the center to the outskirts of Beijing City.  相似文献   
57.
GIS空间分析与模糊综合评判在银行ATM网点选址中的应用   总被引:4,自引:1,他引:3  
黎雯  周廷刚  张伟 《测绘科学》2008,33(1):229-231,237
空间分析是GIS的核心和灵魂,是GIS区别于一般信息系统的主要标志之一。运用GIS空间分析中的叠置分析、缓冲区分析、网络分析等功能对自动柜员机(ATM)网点进行选址,应用模糊综合评判模型对选址区位评价确定出ATM布放的最终布局,并通过实例验证该方法能为在ATM网点选址中提供决策依据,最后探讨了今后研究的方向。  相似文献   
58.
Accuracy assessment of lidar-derived digital elevation models   总被引:2,自引:0,他引:2  
Despite the relatively high cost of airborne lidar-derived digital elevation models (DEMs), such products are usually presented without a satisfactory associated estimate of accuracy. For the most part, DEM accuracy estimates are typically provided by comparing lidar heights against a finite sample of check point coordinates from an independent source of higher accuracy, supposing a normal distribution of the derived height differences or errors. This paper proposes a new methodology to assess the vertical accuracy of lidar DEMs using confidence intervals constructed from a finite sample of errors computed at check points. A non-parametric approach has been tested where no particular error distribution is assumed, making the proposed methodology especially applicable to non-normal error distributions of the type usually found in DEMs derived from lidar. The performance of the proposed model was experimentally validated using Monte Carlo simulation on 18 vertical error data-sets. Fifteen of these data-sets were computed from original lidar data provided by the International Society for Photogrammetry and Remote Sensing Working Group III/3, using their respective filtered reference data as ground truth. The three remaining data-sets were provided by the Natural Environment Research Council's Airborne Research and Survey Facility lidar system, together with check points acquired using high precision kinematic GPS. The results proved promising, the proposed models reproducing the statistical behaviour of vertical errors of lidar using a favourable number of check points, even in the cases of data-sets with non-normally distributed residuals. This research can therefore be considered as a potentially important step towards improving the quality control of lidar-derived DEMs.  相似文献   
59.
居住单元是与人们生活密切相关的社区范围,其交通环境的优劣是衡量居住单元环境好坏的重要标准之一。高分辨遥感影像 的高空间分辨率特点为我们提供了研究居住单元交通环境的可能性。本文从区域交通环境、路网可达性出发,对城市居住单元交通 环境质量的遥感评价方法进行了研究,根据高分辨率遥感影像的特点构建了居住单元交通环境的多级指标评价体系,并对厦门市的 50个居住单元进行了评价分析。实验表明,利用高分辨率影像进行城市交通环境质量评价是一种成本较低,简便可行的方法。  相似文献   
60.
由于地质灾害的突发性和引发因素的复杂性,在及时和有效地掌握潜在隐患部位上还亟待进一步探索与细化,力求防灾抗灾工作有的放矢,以确保人民群众的生命财产损失降到最低限度。本文就基于山区的基本特征和房后边坡潜在地质安全隐患基本信息调查,简要分析房后边坡孕灾致灾环境,并针对它们的影响程度,采取层次分析(AHP)等方法来确定安全评价因子权重和安全系数,对构造安全评价结构作进一步研究。  相似文献   
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