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241.
A. D. Gilbert C. Froeschlé U. Frisch 《Celestial Mechanics and Dynamical Astronomy》1993,56(1-2):263-272
Wavelet analysis is applied to distributions of points generated by iterating the standard map. The initial condition is chosen so that the points fill the largest chaotic region. When the standard map parameterk=1.3, the distribution of points contains many voids corresponding to islands in the chaotic region. The wavelet transform is dominated by contributions from these islands. Fork=10 the chaos fills phase space and no structure is apparent; the wavelet transform reveals statistical fluctuations in the distribution of points. 相似文献
242.
GIS-based hazard mapping and zonation of debris flows in Xiaojiang Basin,southwestern China 总被引:11,自引:0,他引:11
Y.?P.?HeEmail author H.?Xie P.?Cui F.?Q.?Wei D.?L.?Zhong J.?S.?Gardner 《Environmental Geology》2003,45(2):286-293
Debris flow sites were identified at 140 locations in the Xiaojiang Basin in Yunnan province, southwestern China. Their spatial distribution and catchment characteristics are described in detail on the basis of previous research, air photo interpretation, field investigation and mapping using Geographical Information Systems (GIS). Using a statistical approach, a quantitative model of hazards assessment and zonation was developed through synthesis analysis of basin areas, gradients, and the relative reliefs of these debris flow sites. In terms of debris flow hazard assessment, areas within the Xiaojiang Basin can be classified as severe, heavy and light hazard regions. 相似文献
243.
Knowledge-Driven and Data-Driven Fuzzy Models for Predictive Mineral Potential Mapping 总被引:5,自引:0,他引:5
In this paper, we describe new fuzzy models for predictive mineral potential mapping: (1) a knowledge-driven fuzzy model that uses a logistic membership function for deriving fuzzy membership values of input evidential maps and (2) a data-driven model, which uses a piecewise linear function based on quantified spatial associations between a set of evidential evidence features and a set of known mineral deposits for deriving fuzzy membership values of input evidential maps. We also describe a graphical defuzzification procedure for the interpretation of output fuzzy favorability maps. The models are demonstrated for mapping base metal deposit potential in an area in the south-central part of the Aravalli metallogenic province in the state of Rajasthan, western India. The data-driven and knowledge-driven models described in this paper predict potentially mineralized zones, which occupy less than 10% of the study area and contain at least 83% of the model and validation base metal deposits. A cross-validation of the favorability map derived from using one of the models with the favorability map derived from using the other model indicates a remarkable similarity in their results. Both models therefore are useful for predicting favorable zones to guide further exploration work. 相似文献
244.
数字摄影测量,应用计算机技术、数字影像处理、影像匹配、模式识别等理论与方法,以计算机视觉代替人眼的立体观测,其产品与中间数据的记录以及处理的原始资料均是数字的,较之常规的(传统的)数字产品的生产方法,具有自动化程度高、速度快、成果多样化等优点。两次外业和两次内业,是∶地形图数字摄影测量的主要作业流程,第二次外业调绘作为1500数字摄影测量的主要外业工作与常规调绘方法有一定的区别。∶地形图数字摄影测量适合于1500大面积数字化测图。 相似文献
245.
Main concepts of the "European approach" to karst-groundwater-vulnerability assessment and mapping 总被引:4,自引:1,他引:3
D. Daly A. Dassargues D. Drew S. Dunne N. Goldscheider S. Neale I. Popescu F. Zwahlen 《Hydrogeology Journal》2002,10(2):340-345
In order to achieve some consistency in the establishment of groundwater intrinsic vulnerability maps in Europe, a new approach
is proposed by Working Group 1 of the European COST Action 620 on "Vulnerability mapping for the protection of carbonate (karst)
aquifers". A general procedure is offered which provides consistency while allowing the required flexibility for application
to a continent and under conditions of varying geology, scale, information availability, time, and resources.
The proposed methodology is designed to be clearly more physically based than the existing vulnerability-mapping techniques.
It takes the specificity of the karstic environments into account without necessarily excluding the applicability to other
geological conditions. Combined "core factors" for overlying layers and for concentration of flow account for the relative
protection of groundwater from contamination while taking into account any bypass of the overlying layers.
A precipitation factor is distinguished for describing characteristics of the input of water to the system. Differentiation
is made between groundwater resource intrinsic vulnerability mapping and source intrinsic vulnerability mapping. For the latter,
a factor describing the karst network development is relevant. This short technical note describes a first step in the work
program of Working Group 1 of the COST Action 620. Future steps are now in progress to quantify the approach and to apply
it in various European pilot areas.
Electronic Publication 相似文献
246.
在分析了当前测绘仪器管理存在问题的基础上,从仪器在实验室的管理体制、模式方面做了有益探讨和分析,提出了测绘仪器实行动态管理和开放使用的模式。 相似文献
247.
248.
数字测绘技术在城镇地籍测量中的应用 总被引:1,自引:0,他引:1
通过实例简述了数字化测绘技术在城镇地籍测量中作业流程、实施过程与地籍管理信息系统的建立过程。说明用该技术作业效率与成果精度比较高。 相似文献
249.
测绘标准管理信息系统是标准信息化建设的主要内容,是测绘标准信息管理、应用及服务的重要基础支撑平台。本文结合开展测绘标准管理信息系统研究和建立的实际经验,根据标准信息建设与服务的技术现状和发展趋势,从设计要求、系统功能框架、标准信息管理、标准化工作管理、安全性和数据备份等方面介绍了测绘标准管理信息系统的设计思路,并就其实现方法和所采用的相应技术作了简单的叙述。 相似文献
250.
中国古代测绘发展具有显著特点。本文基于大量测绘史料,论述了中国古代测绘发展道路的独创性、发展速度的跳跃性、测绘方法的实用性等特点及其形成原因,反映了测绘科学发展的若干规律,这对于今天的测绘科技创新具有借鉴意义。 相似文献